Herbs, Herbal Compounds and Nutrients that Synergize with Chemotherapeutic Agents

by John G. Connor, M.Ac., L.Ac., edited by Barbara Connor, M.Ac., L.Ac.

Table of Contents
Introduction
Summaries of Synergetic Actions between Herbs, Herbal Compounds and Nutrients and Chemotherapeutic Agents
Abstracts Examined
Other Recently Published Related Reviews & Studies
Appendix

Introduction
Cancer cells exhibit deregulation in multiple cellular signaling pathways. Therefore, treatments using specific agents that target only one pathway usually fail in cancer therapy. The combination treatments using chemotherapeutic agents with distinct molecular mechanisms are considered more promising for higher efficacy; however, using multiple agents contributes to added toxicity. Emerging evidence has shown that some “natural products” such as isoflavones, indole-3-carbinol (I3C) and its in vivo dimeric product 3,3′-diindolylmethane (DIM), and curcumin among many others, have growth inhibitory and apoptosis inducing effects on human and animal cancer cells mediated by targeting multiple cellular signaling pathways in vitro without causing unwanted toxicity in normal cells. Therefore, these non-toxic “natural products” from natural resources could be useful in combination with conventional chemotherapeutic agents for the treatment of human malignancies with lower toxicity and higher efficacy.  (For recent 2009 published studies on indole-3-carbinol and DIM in relation to breast and prostate cancer please see Appendix.)

In fact, recently increasing evidence from pre-clinical in vivo studies and clinical trials have shown some success in support of the use of rational design of multi-targeted therapies for the treatment of cancers using conventional chemotherapeutic agents in combination with “natural products”. These studies have provided promising results and further opened-up newer avenues for cancer therapy. In this review article, we have succinctly summarized the known effects of “natural products” especially by focusing on isoflavones, indole-3-carbinol (I3C) and its in vivo dimeric product 3,3′-diindolylmethane (DIM), and curcumin, and provided a comprehensive view on the molecular mechanisms underlying the principle of cancer therapy using combination of “natural products” with conventional therapeutics. Cancer Treat Rev. 2009 Aug 4. [Epub ahead of print] (Sarkar FHLi Y. 2009)

Given the multiple effects of these natural agents, their future use for cancer therapy probably lies in synergistic combinations.  During active cancer therapy, they should generally be evaluated in combination with chemotherapy and radiation. In this role, they act as modifiers of biologic response or as adaptogens, potentially enhancing the efficacy of the conventional therapies. Curr Oncol.2006 Feb;13(1):14-26. (Sagar SMYance DWong RK. 2006)

Because botanicals contain a variety of organic chemical complexes, they usually act on multiple targets.  A potential advantage of phytochemicals is that they may act through multiple pathways and reduce the development of resistance by cancer cells. Curr Oncol. 2006 Feb;13(1):14-26. (Sagar SMYance DWong RK. 2006)

Teamwork between the oncologist, the herbalist, the laboratory scientist, and the research methodologist is important for studying anti-angiogenic herbs and other natural health products.  As clinical trials introduce these products into the clinic, more definitive evidence of efficacy will be provided and more cancer patients may potentially experience improved outcomes. Curr Oncol. 2006 Feb;13(1):14-26. (Sagar SMYance DWong RK. 2006)

Herbal Compounds and Nutrients with Chemotherapeutic Agents
I have compiled the following summaries based on 67 published scientific studies – abstracts of which are included later on in this article. I have excluded from this compilation all studies that are prior to the year 2003.

These studies examine the actions of 10 different herbs, 27 herbal compounds and 14 nutrients with 28 different chemotherapeutic agents, 1 NSAID, and 1 COX-2 inhibitor.

54 of these studies have demonstrated synergistic actions between herbs, herbal compounds or nutrients and chemotherapeutic agents.

 Out of the above studies there are 17 human studies, 17 animal studies and 36 in vitro studies.

The Breakdown of the 17 Human Studies is as Follows:·  
   
Randomized double-blind, placebo-controlled study – 1
Double-blind, placebo-controlled study – 1
Meta-analysis of randomized trials – 1
Randomized controlled trial – 1  
Phase II trials – 2  
Open label study – 1  
Safety and pharmacokinetic study – 1  
Clinical studies – 4
Epidemiological studies – 5


 Chemotherapeutic Agent Herb, Herbal Compound or Nutrient in Study
5-FU (5-fluorouracil) ———— Ginkgo biloba extract; Green Tea; Panax notoginseng ……………………………………………….. root extract; Panaxadiol; Asian ginseng
5-FU & oxaliplatin (FOLFOX)   Curcumin
Arabinosylcytosine ————– Fatty Acids
Capecitabine ——————— Curcumin
Carboplatin ———————- Silibinin
cDDP —————————— Quercetin
Chlorambucil——————— Honokiol
Cisplatin —————————Fish oil, Vit. A, Vit E & Selenium; Luzea c., Rhodiola r. ……………………………………………….. Eleutherococcus senticosus & Schizandra; Resveratrol ……………………………………………….. and genistein; Grape seed proantho-cyanidin extract; ……………………………………………….. Acetyl-L-carnitine 
Cladribine ———————— Honokiol
Cyclophosphamide (Cytoxan) — Licorice extract; Luzea c., Rhodiola rosea., ……………………………………………….. Eleutherococcus senticosus & Schizandra; Andrographis ………………………………………………. paniculata and andrographolide; Uncaria tomentosa bark ……………………………………………… (Pentacyclic oxindole alkaloid mitraphylline) 
Cyclophosphamide & radiation Andrographis paniculata
Docetaxel ————————– Fatty Acids; Astragalus; Resveratrol
Doxorubicin (Adriamycin) —– Grape seed extract; Silibinin; Withania somnifera extract; ————————————- Fatty Acids; Quercetin
Epirubicin ———————— Fatty Acids
Etoposide ————————- Honokiol; Quercetin
Faslodex ————————– Parthenolide
Fludarabine ———————– Honokiol
Gemcitabine ———————- Curcumin
Gemcitabine & paclitaxel ——- Curcumin; Green Tea
Herceptin (Trastuzumab) ——- Fatty Acids
Idarubicin ————————- DIM
Irinotecan ————————- Panax notoginseng root extract; Fatty Acids
Mitomycin C ———————- Green Tea; Resveratrol and Genistein; Fatty Acids
Oxaliplatin ———————— Acetyl-L-carnitine
Paclitaxel ————————– Resveratrol; Acetyl-L-carnitine; Vitamin E
Platinum-based chemo ———- Astragalus
Tamoxifen ————————- CoQ10, Riboflavin & Niacin; Soy; Flaxseed; Selenium; Ginseng; Black Cohosh
Vincristine ———————— Mistletoe; Uncaria tomentosa bark (Pentacyclic oxindole ————————————-  alkaloid mitraphylline)

Abstracts Examined 
Acetyl-L-carnitine
Paclitaxel and Cisplatin-induced neurotoxicity: a protective role of acetyl-L-carnitine.
PURPOSE: Antineoplastic drugs belonging to platinum or taxane families are severely neurotoxic, inducing the onset of disabling peripheral neuropathies with different clinical signs. Acetyl-L-carnitine (ALC) is a natural occurring compound with a neuroprotective activity in several experimental paradigms. In this study we have tested the hypothesis that ALC may have a protective role on cisplatin and paclitaxel-induced neuropathy. EXPERIMENTAL DESIGN: Sensory nerve conduction velocity (SNCV) was measured in rats before, at end, and after an additional follow-up period from treatments with cisplatin, paclitaxel, or with the respective combination with ALC. In addition, serum from treated animals was collected to measure the levels of circulating NGF, and left sciatic nerves were processed for light and electron microscope observations. ALC interference on cisplatin and paclitaxel antitumor activity and protective mechanisms were investigated using several in vitro and in vivo models. RESULTS: ALC cotreatment was able to significantly reduce the neurotoxicity of both cisplatin and paclitaxel in rat models, and this effect was correlated with a modulation of the plasma levels of NGF in the cisplatin-treated animals. Moreover, experiments in different tumor systems indicated the lack of interference of ALC in the antitumor effects of cisplatin and paclitaxel. The transcriptional profile of gene expression in PC12 cells indicated that ALC, in the presence of NGF, was able to positively modulate NGFI-A expression, a gene relevant in the rescue from tissue-specific toxicity. Finally, the transcriptionally ALC-mediated effects were correlated to increase histone acetylation. CONCLUSION: In conclusion, our results indicate that ALC is a specific protective agent for chemotherapy-induced neuropathy after cisplatin or paclitaxel treatment without showing any interference with the antitumor activity of the drugs. Clin Cancer Res. 2003 Nov 15;9(15):5756-67. (Pisano C, et al 2003)

Acetyl-L-Carnitine prevents and reverts experimental chronic neurotoxicity induced by oxaliplatin, without altering its antitumor properties.BACKGROUND: Oxaliplatin (OHP) is severely neurotoxic and induces the onset of a disabling sensory peripheral neuropathy. Acetyl-L-carnitine (ALC), a natural compound with neuroprotective action, was tested to determine whether it plays a protective role in OHP-induced neuropathy. MATERIALS AND METHODS: Peripheral neuropathy was induced in Wistar rats, and the effect of OHP alone or in combination with ALC was assessed, using behavioral and neurophysiological methods. Moreover, ALC interference on OHP antitumor activity was investigated using several in vitro and in vivo models. RESULTS: ALC-co-treatment reduced the neurotoxicity of OHP when it was coadministered. Furthermore, the administration-of OHP, once OHP-induced neuropathy was established, significantly mitigated its severity. Finally, experiments in different tumor systems indicated that ALC does not interfere with the antitumor effects of OHP.CONCLUSION: ALC is effective in the prevention and treatment of chronic OHP-induced peripheral neurotoxicity in an experimental rat model. Anticancer Res. 2005 Jul-Aug;25(4):2681-7. (Ghirardi O, et al 2005)

Acetyl-L-carnitine prevents and reduces paclitaxel-induced painful peripheral neuropathy.
This study examines the potential efficacy of acetyl-L-carnitine (ALC) to prevent and treat paclitaxel-induced pain. Rats received four intraperitoneal (i.p.) injections of 2 mg/kg paclitaxel on alternate days which, following a short delay induced marked mechanical hypersensitivity. Daily administration of ALC (50 mg/kg and 100 mg/kg; p.o.; concurrently with paclitaxel and for 14 days afterwards) prevented the development of paclitaxel-induced pain. This effect was long lasting, for at least 3 weeks after the last dose of ALC. In a separate experiment, daily administration of ALC (100 mg/kg; p.o.; for 10 days) to rats with established paclitaxel-induced pain produced an analgesic effect. This effect dissipated shortly after ALC treatment was withdrawn. We conclude that ALC may be useful in the prevention and treatment of chemotherapy-induced painful peripheral neuropathy. Neurosci Lett. 2006 Apr 24;397(3):219-23. Epub 2006 Jan 6. (Flatters SJXiao WH,Bennett GJ.2006)

Andrographis paniculata extract
Effect of Andrographis paniculata as an adjuvant in combined chemo-radio and whole body hyperthermia treatment – a preliminary study.
Modulation of immune responses to alleviate disease has been of interest for a long time. Intraperitoneal administration of Andrographis paniculata extract along with whole body hyperthermia (WBH) was found to enhance the total WBC count in cyclophosphamide (CTX) and radiation treated animals when compared to untreated control animals. Maximum inhibition in the solid tumor development was observed when the CTX and radiation exposed animals were treated with extract in combination with whole-body hyperthermia. Similarly myeloperoxidase activity in tumor tissue from CTX and radiation-treated animals was also significantly inhibited when they were administered with Andrographis paniculata extract along with whole body hyperthermia. Moreover the production of cytokines such as IL-2 and GM-CSF, which was reduced after combined CTX and radiation treatment was significantly increased by the simultaneous treatment of extract and whole body hyperthermia. The elevated level of serum Tumor Necrosis Factor (TNF-alpha) level, after CTX and radiation treatment was also lowered significantly after the administration of extract and simultaneous exposure of whole-body hyperthermia with respect to untreated tumor-bearing animals. Immunopharmacol Immunotoxicol. 2008;30(1):181-94. (Sheeja KKuttan G. 2008)

Protective effect of Andrographis paniculata and andrographolide on cyclophosphamide-induced urothelial toxicity.
The protective effect of Andrograhis paniculata and andrographolide (ANDLE) against cyclophosphamide (CTX)-induced urothelial toxicity was investigated in this study. Pretreatment of Swiss albino mice with A paniculata extract (10 mg/dose/animal intraperitoneally [ip]) and ANDLE (500 microg/dose/animal ip) could significantly reduce CTX (1.5 nmol/kg body weight)-induced urothelial toxicity. Morphological and histopathological analysis of urinary bladder of CTX-treated mice showed severe inflammation and dark coloration, whereas A paniculata and ANDLE-treated mice showed almost normal bladder morphology. Elevation of urinary protein level (7.33 +/- 0.3 g/L) by CTX administration was reduced by A paniculata (3.78 +/- 0.4 g/L) and ANDLE treatment (4.19 +/- 0.1 g/L). Urinary urea N2 level, which was elevated after 48 hours of CTX administration (24.25 +/- 0.2 g/L) was found to be reduced by the treatment with A paniculata (14.19 +/- 0.5 g/L) and ANDLE (15.79 +/- 0.4 g/L). A decreased level of reduced glutahione (GSH) content in liver (2.81 +/- 0.1 nmol/mg protein) and bladder (1.20 +/- 0.2 nmol/mg protein) after CTX administration was also increased by the treatment with A paniculata (liver: 5.78 +/- 0.3 nmol/mg protein; bladder: 2.96 +/- 0.2 nmol/mg protein) and ANDLE (liver: 5.14 +/- 0.3 nmol/mg protein; bladder: 2.84 +/- 0.2 nmol/mg protein). Production of the proinflammatory cytokine, tumor necrosis factor-alpha, which was elevated during CTX administration, was found to be inhibited by A paniculata and ANDLE treatment. The lowered level of interleukin-2 and interferon-gamma during CTX treatment was elevated by the administration of A paniculata and ANDLE. Integr Cancer Ther.2006 Sep;5(3):244-51. (Sheeja KKuttan G. 2006)

Antioxidants(pyrrolidine dithiocarbamate, vitamin E, epigallocatechin gallate, and genistein)
Taxol synergizes with antioxidants in inhibiting hormonal refractory prostate cancer cell growth.
Taxanes are chemotherapeutic agents commonly used to treat various carcinomas. Dietary antioxidants, such as vitamin E, green tea extracts, and isoflavones have been used against prostate cancer, and exhibit anticancer effects both in vitro and in vivo. We evaluated the combined effect of taxol (paclitaxel) with pyrrolidine dithiocarbamate, vitamin E, epigallocatechin gallate, and genistein in killing hormone-refractory prostate cancer cells. Those agents were tested on the hormone-refractory prostate cancer cell line PC-3, and the viability of the cells was determined using MTT {3 (4, 5-dimethylthiazo-2-yl)-2, 5-diphenyl tetrazolium} assay after drug treatment. PC-3 cells were sensitive to these drugs with 50% inhibitory concentrations of 0.1, 23, 220, 1122, and 260 muM, for taxol, pyrrolidine dithiocarbamate, epigallocatechin gallate, genistein, and vitamin E, respectively. Genistein, pyrrolidine dithiocarbamate, and epigallocatechin gallate showed synergistic cytotoxicity to PC-3 cells when combined with 0.01 muM taxolOnly high concentration of vitamin E showed a synergistic effect with this dose of taxol. Further study revealed that 3 combinations could induce sub-G1 phase of cell cycle, induce apoptosis, and increase caspase activity and decrease Bcl-2 expression simultaneously. In conclusion, in addition to vitamin E, incorporation of these antioxidants with taxan-based cytotoxic therapies offers encouraging strategies for combating hormone-refractory prostate cancers. Urol Oncol. 2008 Sep 23. [Epub ahead of print] (Ping SY,Hour TCLin SRYu DS.2008)

Asian ginseng
Asian ginseng enhances the anti-proliferative effect of 5-fluorouracil on human colorectal cancer: comparison between white and red ginseng.
Previous studies showed that Asian ginseng, Panax ginseng C.A. Meyer, may have anti-cancer properties. However, there is limited data exploring the use of Asian ginseng as an adjuvant to chemotherapy, and minimal mechanistic studies related to their possible synergistic activities. In this study, the content of 8 ginsenosides, Rb1, Rb2, Rb3, Rc, Rd, Re, Rg1 and Rg3, in the extracts of white ginseng (WG) and red ginseng (RG) were determined by HPLC. Using HCT-116 human colorectal cancer cells, we compared the efficacy of WG and RG. We evaluated the synergy between ginseng and 5-fluorouracil (5-FU), and explored the mechanism of their anti-proliferative effects. As single extract, WG or RG used at concentrations of 0.1, 0.2 and 0.3 mg/mL, inhibited HCT-116 cell proliferation in a concentration-related manner. WG at 0.2 mg/mL did not show obvious synergy with 5-FU co-treatment, while RG at 0.2 and 0.3 mg/mL significantly enhanced the anti-proliferative effects of 5-FU at concentrations of 10, 50 and 100 microM (P < 0.05). Using flow cytometric assay, RG 0.3 mg/mL did not affect cancer cell apoptotic induction activity. However, the RG induced cell cycle arrest in the G1 phase, while 5-FU arrested the cell in the S phase. Different ginsenoside profiles are responsible for the observed differences in pharmacological effects. The effects of 8 ginsenosides on HCT-116 cells were assayed. Rd and Rg3 showed positive anti-proliferative effect. Our data suggested a potential for RG as an adjuvant therapy in the treatment of colorectal cancer, via a synergistic action. Arch Pharm Res. 2009 Apr;32(4):505-13. Epub 2009 Apr 29. (Fishbein AB, et al 2009)

Astragalus
Astragalus-based Chinese herbs and platinum-based chemotherapy for advanced non-small-cell lung cancer: meta-analysis of randomized trials.PURPOSE: Systemic treatments for advanced non-small-cell lung cancer have low efficacy and high toxicity. Some Chinese herbal medicines have been reported to increase chemotherapy efficacy and reduce toxicity. In particular, Astragalus has been shown to have immunologic benefits by stimulating macrophage and natural killer cell activity and inhibiting T-helper cell type 2 cytokines. Many published studies have assessed the use of Astragalus and other Chinese herbal medicines in combination with chemotherapy. We sought to evaluate evidence from randomized trials that Astragalus-based Chinese herbal medicine combined with platinum-based chemotherapy (versus platinum-based chemotherapy alone) improves survival, increases tumor response, improves performance status, or reduces chemotherapy toxicity. METHODS: We searched CBM, MEDLINE, TCMLARS, EMBASE, Cochrane Library, and CCRCT databases for studies in any language. We grouped studies using the same herbal combinations for random-effects meta-analysis. RESULTS: Of 1,305 potentially relevant publications, 34 randomized studies representing 2,815 patients met inclusion criteria. Twelve studies (n = 940 patients) reported reduced risk of death at 12 months (risk ratio [RR] = 0.67; 95% CI, 0.52 to 0.87). Thirty studies (n = 2,472) reported improved tumor response data (RR = 1.34; 95% CI, 1.24 to 1.46). In subgroup analyses, Jin Fu Kang in two studies (n = 221 patients) reduced risk of death at 24 months (RR = 0.58; 95% CI, 0.49 to 0.68) and in three studies (n = 411) increased tumor response (RR = 1.76; 95% CI, 1.23 to 2.53). Ai Di injection (four studies; n = 257) stabilized or improved Karnofsky performance status (RR = 1.28; 95% CI, 1.12 to 1.46). CONCLUSION: Astragalus-based Chinese herbal medicine may increase effectiveness of platinum-based chemotherapy when combined with chemotherapy. These results require confirmation with rigorously controlled trials. J Clin Oncol. 2006 Jan 20;24(3):419-30. (McCulloch M, et al 2006)

Safety and pharmacokinetic trial of docetaxel plus an Astragalus-based herbal formula for non-small cell lung cancer patients.
PURPOSE: To study a commonly used Astragalus-based herbal formula previously found effective in non-small cell lung cancer (NSCLC) on the pharmacokinetics of docetaxel in patients with NSCLC. METHODS: Patients with advanced NSCLC who progressed after prior platinum-containing chemotherapy were accrued and received docetaxel at 35 mg/m(2) for 3 weeks followed by 1 week of rest. At 4 days prior to the second dosing, Jinfukang was given orally. Pharmacokinetic studies of initial-dose docetaxel (in the absence of Jinfukang) and the third dose (in the presence of Jinfukang) were compared. RESULTS: Of the 24 patients enrolled, 21 started Jinfukang and docetaxel. Jinfukang had no significant impact on the pharmacokinetics of docetaxel. Median time to progression or withdrawal from treatment was 7 weeks. Twelve patients were removed from study for progression of disease; nine patients withdrew. CONCLUSIONS: Jinfukang did not alter the pharmacokinetics of docetaxel nor appear to affect survival in this study. Cancer Chemother Pharmacol. 2009 Dec;65(1):67-71. Epub 2009 May 7. (Cassileth BR, et al 2009)

Citronellol, Ganoderma lucidum, Codonopsis pilosula and Angelica sinensisEffect of citronellol and the Chinese medical herb complex on cellular immunity of cancer patients receiving chemotherapy/radiotherapy.
Leukopenia and immunity impairment usually occur during cancer therapy. Citronellol, an oil soluble compound derived from the geranium, has anticancer and antiinflammatory properties, as well as promoting wound healing. Ganoderma lucidum, Codonopsis pilosula and Angelicae sinensis are traditional Chinese herbs, all of which have proven immunomodulatory functions in laboratory-based research. This randomized, double-blind, placebo-controlled study examined whether the Chinese medicinal herb complex (CCMH; a mixture of citronellol and extracts of G. lucidum, C. pilosula and A. sinensis) improves the immune cell counts of cancer patients receiving chemotherapy and/or radiotherapy. A total of 105 cancer patients receiving chemotherapy or radiotherapy were enrolled. The quantities of immune cells in the blood of the subjects were determined before and after 6 weeks of cancer treatment, with either CCMH or a placebo. CCMH significantly reduced the depletion of leukocytes (14.2% compared with 28.2%) and neutrophils (11.0% compared with 29.1%). Analysis of the lymphocyte phenotype revealed that the patients receiving the placebo had reduced CD4 lymphocytes and natural killer (NK) cells than the CCMH-treated patients. Treatment with CCMH for patients receiving chemotherapy and/or radiotherapy may improve their immune function, improving their ability to fight off the cancer, as well as any secondary infections that could compromise their treatment and their health.Phytother Res. 2009 Jun;23(6):785-90(Zhuang SR, et al 2009).

CoQ10, Riboflavin & Niacin
Effect of Coenzyme Q(10), Riboflavin and Niacin on Tamoxifen treated postmenopausal breast cancer women with special reference to bloodchemistry profiles.
Background Tamoxifen (TAM) a non-steroidal antiestrogen, is widelyused in adjuvant therapy for all stages of breast carcinomas and inchemoprevention of high-risk group. TAM also has estrogenic activityon liver and endometrium causing severe oxidative stress withvarious biochemical derangements. Coenzyme Q(10), Riboflavin and Niacin (CoRN) are well-known potent antioxidants and protective agents against many diseases including cancer. In this context, this study was undertaken to find if co-administration of TAM along with CoRN could alleviate the sole TAM-induced biochemical derangements in postmenopausal women with breast cancer. Method The vitamin supplementation with TAM was given for a period of 90 days. Blood samples were collected at the base line, 45th and 90th day during the course of treatment. Various blood chemistry profiles were assessed in 78 untreated, sole TAM treated and combinatorial treated group along with 46 age- and sex-matched controls. Results A statistically significant alteration in various blood chemistry parameters, such as serum total bilirubin (S. BIL), serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), gamma glutamyl transpeptidase (gamma-GT), uric acid (UA), lipoprotein lipase (LPL), lecithin: cholesterol acyl transferases (LCAT), potassium, calcium and Na(+), K(+)-ATPase in sole TAM-treated group, was favorably reverted back to near normal levels on combinatorial therapy with CoRN. Conclusion TAM on coadministration with CoRN has a favorable impact on various blood chemistry profiles. However, large scale randomized studies over a longer time span are required to ascertain the safety and efficacy of co-administrating antioxidants with conventional chemotherapy. Breast Cancer Res Treat. 2008 Apr 22. [Epub ahead of print] (Yuvaraj S, et al 2008)

Curcumin
Phase II trial of curcumin in patients with advanced pancreatic cancer.
PURPOSE: Pancreatic cancer is almost always lethal, and the only U.S. Food and Drug Administration-approved therapies for it, gemcitabine and erlotinib, produce objective responses in <10% of patients. We evaluated the clinical biological effects of curcumin (diferuloyl-methane), a plant-derived dietary ingredient with potent nuclear factor-kappaB (NF-kappaB) and tumor inhibitory properties, against advanced pancreatic cancer. EXPERIMENTAL DESIGN: Patients received 8 g curcumin by mouth daily until disease progression, with restaging every 2 months. Serum cytokine levels for interleukin (IL)-6, IL-8, IL-10, and IL-1 receptor antagonists and peripheral blood mononuclear cell expression of NF-kappaB and cyclooxygenase-2 were monitored. RESULTS: Twenty-five patients were enrolled, with 21 evaluable for response. Circulating curcumin was detectable as drug in glucuronide and sulfate conjugate forms, albeit at low steady-state levels, suggesting poor oral bioavailability. Two patients showed clinical biological activity. One had ongoing stable disease for >18 months; interestingly, one additional patient had a brief, but marked, tumor regression (73%) accompanied by significant increases (4- to 35-fold) in serum cytokine levels (IL-6, IL-8, IL-10, and IL-1 receptor antagonists). No toxicities were observed. Curcumin down-regulated expression of NF-kappaB, cyclooxygenase-2, and phosphorylated signal transducer and activator of transcription 3 in peripheral blood mononuclear cells from patients (most of whom had baseline levels considerably higher than those found in healthy volunteers). Whereas there was considerable interpatient variation in plasma curcumin levels, drug levels peaked at 22 to 41 ng/mL and remained relatively constant over the first 4 weeks. CONCLUSIONS: Oral curcumin is well tolerated and, despite its limited absorption, has biological activity in some patients with pancreatic cancer. Clin Cancer Res. 2008 Jul 15;14(14):4491-9. Comment in: Clin Cancer Res. 2009 Jan 15;15(2):747; author reply 747.  (Dhillon N, et al 2008)  

Curcumin potentiates antitumor activity of gemcitabine in an orthotopic model of pancreatic cancer through suppression of proliferation, angiogenesis, and inhibition of nuclear factor-kappaB-regulated gene products.
Gemcitabine is currently the best treatment available for pancreatic cancer, but the disease develops resistance to the drug over time. Agents that can either enhance the effects of gemcitabine or overcome chemoresistance to the drug are needed for the treatment of pancreatic cancer. Curcumin, a component of turmeric (Curcuma longa), is one such agent that has been shown to suppress the transcription factor nuclear factor-kappaB (NF-kappaB), which is implicated in proliferation, survival, angiogenesis, and chemoresistance. In this study, we investigated whether curcumin can sensitize pancreatic cancer to gemcitabine in vitro and in vivo. In vitro, curcumin inhibited the proliferation of various pancreatic cancer cell lines, potentiated the apoptosis induced by gemcitabine, and inhibited constitutive NF-kappaB activation in the cells. In vivo, tumors from nude mice injected with pancreatic cancer cells and treated with a combination of curcumin and gemcitabine showed significant reductions in volume (P = 0.008 versus control; P = 0.036 versus gemcitabine alone), Ki-67 proliferation index (P = 0.030 versus control), NF-kappaB activation, and expression of NF-kappaB-regulated gene products (cyclin D1, c-myc, Bcl-2, Bcl-xL, cellular inhibitor of apoptosis protein-1, cyclooxygenase-2, matrix metalloproteinase, and vascular endothelial growth factor) compared with tumors from control mice treated with olive oil only. The combination treatment was also highly effective in suppressing angiogenesis as indicated by a decrease in CD31(+) microvessel density (P = 0.018 versus control). Overall, our results suggest that curcumin potentiates the antitumor effects of gemcitabine in pancreatic cancer by suppressing proliferation, angiogenesis, NF-kappaB, and NF-kappaB-regulated gene products. Cancer Res. 2007 Apr 15;67(8):3853-61. (Kunnumakkara AB, et al 2007)

Curcumin sensitizes human colorectal cancer to capecitabine by modulation of cyclin D1, COX-2, MMP-9, VEGF and CXCR4 expression in an orthotopic mouse model.
Because of the poor prognosis and the development of resistance against chemotherapeutic drugs, the current treatment for advanced metastatic colorectal cancer (CRC) is ineffective. Whether curcumin (a component of turmeric) can potentiate the effect of capecitabine against growth and metastasis of CRC was investigated. The effect of curcumin on proliferation of CRC cell lines was examined by mitochondrial dye-uptake assay, apoptosis by esterase staining, nuclear factor-kappaB (NF-kappaB) by electrophoretic mobility shift assay and gene expression by Western blot analysis. The effect of curcumin on the growth and metastasis of CRC was also examined in orthotopically implanted tumors in nude mice. In vitro, curcumin inhibited the proliferation of human CRC cell lines, potentiated capecitabine-induced apoptosis, inhibited NF-kappaB activation and suppressed NF-kappaB-regulated gene products. In nude mice, the combination of curcumin and capecitabine was found to be more effective than either agent alone in reducing tumor volume (p = 0.001 vs. control; p = 0.031 vs. capecitabine alone), Ki-67 proliferation index (p = 0.001 vs. control) and microvessel density marker CD31. The combination treatment was also highly effective in suppressing ascites and distant metastasis to the liver, intestines, lungs, rectum and spleen. This effect was accompanied by suppressed expression of activated NF-kappaB and NF-kappaB-regulated gene products (cyclin D1,c-myc, bcl-2, bcl-xL, cIAP-1, COX-2, ICAM-1, MMP-9, CXCR4 and VEGF). Overall, our results suggest that curcumin sensitizes CRC to the antitumor and antimetastatic effects of capecitabine by suppressing NF-kappaB cell signaling pathway.Int J Cancer. 2009 Nov 1;125(9):2187-97. (Kunnumakkara AB, et al 2009)

Curcumin potentiates the antitumor effects of gemcitabine in an orthotopic model of human bladder cancer through suppression of proliferative and angiogenic biomarkers.
Little progress has been made in the last three decades in the treatment of bladder cancer. Novel agents that are nontoxic and can improve the current standard of care of this disease are urgently needed. Curcumin, a component of Curcuma longa (also called turmeric), is one such agent that has been shown to suppress pathways linked to oncogenesis, including cell survival, proliferation, invasion and angiogenesis. We investigated whether curcumin has potential to improve the current therapy for bladder cancer, using an orthotopic mouse model. Curcumin potentiated the apoptotic effects of gemcitabine against human bladder cancer 253JBV cells in culture. Electrophoretic mobility shift assay revealed that curcumin also suppressed the gemcitabine-induced activation of the cell survival transcription factor NF-kappaB. In an orthotopic mouse model, bioluminescence imaging revealed that while curcumin alone significantly reduced the bladder tumor volume, maximum reduction was observed when curcumin was used in combination with gemcitabine. Overall our results suggest that curcumin alone exhibits significant antitumor effects against human bladder cancer and it further potentiates the effects of gemictabine, possibly through the modulation of NF-kappaB signaling pathway. Biochem Pharmacol. 2009 Aug 12. [Epub ahead of print] (Tharakan ST et al 2009)

Curcumin enhances the effects of 5-fluorouracil and oxaliplatin in mediating growth inhibition of colon cancer cells by modulating EGFR and IGF-1R.
Curcumin (diferuloylmethane), which has been shown to inhibit growth of transformed cells, has no discernible toxicity and achieves high levels in colonic mucosa. 5-fluorouracil (5-FU) or 5-FU plus oxaliplatin (FOLFOX) remains the backbone of colorectal cancer chemotherapeutics, but with limited success. The present investigation was, therefore, undertaken to examine whether curcumin in combination with conventional chemotherapeutic agent(s)/regimen will be a superior therapeutic strategy for colorectal cancer. Indeed, results of our in vitro studies demonstrated that curcumin together with FOLFOX produced a significantly greater inhibition (p < 0.01) of growth and stimulated apoptosis (p < 0.001) of colon cancer HCT-116 and HT-29 cells than that caused by curcumin, 5-FU, curcumin + 5-FU or FOLFOX. These changes were associated with decreased expression and activation (tyrosine phosphorylation) of EGFR, HER-2, HER-3 (72-100%) and IGF-1R (67%) as well as their downstream effectors such as Akt and cycloxygenase-2 (51-97%). Furthermore, while these agents produced a 2-3-fold increase in the expression of IGF-binding protein-3 (IGFBP-3), curcumin together with FOLFOX caused a 5-fold increase in the same, when compared to controls. This in turn led to increased sequestration of IGF by IGFBP-3 rendering IGF-1 unavailable for binding to and activation of IGF-1R. We conclude that the superior effects of the combination therapy of curcumin and FOLFOX are due to attenuation of EGFRs and IGF-1R signaling pathways. We also suggest that inclusion of curcumin to the conventional chemotherapeutic agent(s)/regimen could be an effective therapeutic strategy for colorectal cancer. Int J Cancer. 2008 Jan 15;122(2):267-73.  (Patel BB, et al 2008)

Curcumin potentiates the apoptotic effects of chemotherapeutic agents and cytokines through down-regulation of nuclear factor-kappaB and nuclear factor-kappaB-regulated gene products in IFN-alpha-sensitive and IFN-alpha-resistant human bladder cancer cells.
Bladder cancer mortality varies between the countries; whereas being highest in Western countries, it is lowest in Eastern countries, such as India. Cigarette smoking is one of the major risk factors for bladder cancer in affluent nations, such as United States. Localized early-stage bladder cancer is treated with resection and intravesical cytokine therapy, whereas metastatic cancer is typically treated with various combinations of systemic chemotherapy. Whether curcumin, a yellow curry pigment commonly consumed in countries, such as India, has any role in prevention or treatment of bladder cancer was investigated. We found that curcumin inhibited the proliferation, induced cell cycle arrest, and DNA fragmentation in both IFN-alpha-sensitive (RT4V6) and IFN-alpha-resistant (KU-7) bladder cancer cells. Curcumin also potentiated the apoptotic effects of the chemotherapeutic agents (gemcitabine and paclitaxel) and of cytokines [tumor necrosis factor (TNF) and TNF-related apoptosis-inducing ligand]. This effect of curcumin was independent of sensitivity and resistance to IFN-alpha, commonly used for treatment of bladder cancer. Whether the effects of curcumin are mediated through modulation of the nuclear factor-kappaB (NF-kappaB) pathway known to mediate antiapoptosis was investigated. Both gemcitabine and TNF activated NF-kappaB in bladder cancer cells and curcumin suppressed this activation. Similarly, cigarette smoke, a major risk factor for bladder cancer, also activated NF-kappaB and curcumin suppressed it. Cigarette smoke-induced expression of the NF-kappaB-regulated gene products cyclooxygenase-2 and vascular endothelial growth factor, linked with proliferation and angiogenesis, respectively, was also down-regulated by curcumin. Mol Cancer Ther. 2007 Mar;6(3):1022-30. (Kamat AMSethi GAggarwal BB 2007)

DIM
3,3-diindolylmethane enhances the inhibitory effect of idarubicin on the growth of human prostate cancer cells
OBJECTIVE: To study the effects of idarubicin (IDA) combined with 3, 3-diindolylmethane (DIM) on the growth inhibition of human prostate cancer cells. METHODS: Human prostate cancer cells of the line PC-3M were cultured and then divided into the following groups: control group with solvent added into the culture fluid; IDA groups, with IDA of the terminal concentrations of 0.5, 1 or 5 mg/L added into the culture fluid; DIM groups, with DIM of the terminal concentrations of 30, 60 or 100 micromol/L added into the culture fluid; and DIM + IDA groups, with 0. 5 mg/L IDA and DIM 30, 60 or 100 micromol/L added into the culture fluid. 48 h later the cell growth inhibition rate was detected by MTT assay. Flow cytometry and acridine orange staining were used to detect the cell cycle and apoptosis. RT-PCR and Western blotting were used to detect the mRNA and protein expression of caspase 9, an apoptosis gene. RESULTS: Both IDA and DIM dose-dependently inhibited the growth of the PC-3M cells. The growth inhibition rate of the 60 micromol/L DIM + 0.5 mg/L IDA group was 69.9%, almost 10 times as that of the 0.5 mg/L IDA group. The apoptosis rate of the 60 micromol/L DIM + 0. 5 mg/L IDA group was 47.0%, significantly higher than that of the 0.5 mg/L IDA group (3.2%, P < 0.05). RT-PCR and Western blotting showed that the combination of DIM and IDA significantly enhanced the mRNA and protein expression of caspase 9. CONCLUSION: DIM enhances the growth inhibition effect of IDA on human prostate cancer cells by the mechanism of induction of apoptosis. Zhonghua Yi Xue Za Zhi. 2008 Mar 11;88(10):661-4. (Zhao YY, et al 2008)

(n-3) fatty acids and cancer therapy.
Supplementing the diet of tumor-bearing mice or rats with oils containing (n-3) (omega-3) or with purified (n-3) fatty acids has slowed the growth of various types of cancers, including lung, colon, mammary, and prostate. The efficacy of cancer chemotherapy drugs such as doxorubicin, epirubicin, CPT-11, 5-fluorouracil, and tamoxifen, and of radiation therapy has been improved when the diet included (n-3) fatty acids. Some potential mechanisms for the activity of (n-3) fatty acids against cancer include modulation of eicosanoid production and inflammation, angiogenesis, proliferation, susceptibility for apoptosis, and estrogen signaling. In humans, (n-3) fatty acids have also been used to suppress cancer-associated cachexia and to improve the quality of life. In one study, the response to chemotherapy therapy was better in breast cancer patients with higher levels of (n-3) fatty acids in adipose tissue [indicating past consumption of (n-3) fatty acids] than in patients with lower levels of (n-3) fatty acids. Thus, in combination with standard treatments, supplementing the diet with (n-3) fatty acids may be a nontoxic means to improve cancer treatment outcomes and may slow or prevent recurrence of cancer. Used alone, an (n-3) supplement may be a useful alternative therapy for patients who are not candidates for standard toxic cancer therapies. J Nutr. 2004 Dec;134(12 Suppl):3427S-3430S. (Hardman WE. 2004)

HER2 (erbB-2)-targeted effects of the omega-3 polyunsaturated fatty acid, alpha-linolenic acid (ALA; 18:3n-3), in breast cancer cells: the “fat features” of the “Mediterranean diet” as an “anti-HER2 cocktail”.
BACKGROUND: Data derived from epidemiological and experimental studies suggest that alphalinolenic acid (ALA; 18:3n-3), the main omega-3 polyunsaturated fatty acid (PUFA) present in the Western diet, may have protective effects in breast cancer risk and metastatic progression. A recent pilot clinical trial assessing the effects of ALA-rich dietary flaxseed on tumor biological markers in postmenopausal patients with primary breast cancer demonstrated significant reductions in tumor growth and in HER2 (erbB-2) oncogene expression. HYPOTHESIS: The molecular mechanism by which ALA inhibits breast cancer cell growth and metastasis formation may involve a direct regulation of HER2, a well-characterized oncogene playing a key role in the etiology, progression and response to some chemo- and endocrine therapies in approximately 20% of breast carcinomas. METHODS: Using HER2-specific ELISA, flow cytometry, immunofluorescence microscopy, Western blotting, RT-PCR and HER2 promoter-reporter analyses, we characterized the effects of exogenous supplementation with ALA on the expression of HER2 oncogene, a master key player in the onset and metastasis formation of breast cancer disease. Metabolic status (MTT) assays were performed to evaluate the nature of the cytotoxic interaction between ALA and the humanized anti-HER2 monoclonal antibody trastuzumab (Herceptin). To study these issues we used BT-474 and SKBr-3 breast cancer cells, which naturally exhibit amplification of the HER2 oncogene. RESULTS: ALA treatment dramatically suppressed the expression of HER2-coded p185Her-2/neu oncoprotein as determined by ELISA, flow cytometry, immunofluorescence microscopy and immunoblotting techniques. Interestingly, ALA-induced down-regulation of p185Her-2/neu correlated with a transcriptional response as no HER2 mRNA signal could be detected by RT-PCR upon treatment with optimal concentrations of ALA (up to 20 microM). Consistent with these findings, ALA exposure was found to dramatically repress the activity of a Luciferase reporter gene driven by the HER2 promoter. Moreover, the nature of the cytotoxic interaction between ALA and trastuzumab (Herceptin) revealed a significant synergism as assessed by MTT-based cell viability assays. CONCLUSIONS: i) These findings reveal that the omega-3 PUFA ALA suppresses overexpression of HER2 oncogene at the transcriptional level, which, in turn, interacts synergistically with anti-HER2 trastuzumab- based immunotherapy. ii) Our results molecularly support a recent randomized double-blind placebo-controlled clinical trial suggesting that ALA may be a potential dietary alternative or adjunct to currently used drugs in the management of HER2-positive breast carcinomas. iii) Considering our previous findings demonstrating the <> of the omega-6 PUFA linolenic acid (LA; 18:2n-6) and the <> of the omega-3 PUFA docosahexaenoic acid (DHA; 22:6n-3) and of the omega-9 monounsaturated fatty acid oleic acid (OA; 18:1n-9), it is reasonable to suggest that a low omega-6/omega-3 PUFA ratio and elevated MUFA levels, the two prominent <> of the <>, should be extremely efficient at blocking HER2 expression in breast cancer cells. Clin Transl Oncol. 2006 Nov;8(11):812-20. (Menéndez JA, et al 2006)

Effect of gamma-linolenic acid on the transcriptional activity of the Her-2/neu (erbB-2) oncogene.
The omega-6 polyunsaturated fatty acid gamma-linolenic acid (GLA; 18:3n-6), which is found in several plant oils and is used as an herbal medicine, has antitumor activity in vitro. We examined the effect of GLA on the expression of the Her-2/neu (erbB-2) oncogene, which is involved in development of numerous types of human cancer. Flow cytometric and immunoblotting analyses demonstrated that GLA treatment substantially reduced Her-2/neu protein levels in the Her-2/neu-overexpressing cell lines BT-474, SK-Br3, and MDA-MB-453 (breast cancer), SK-OV3 (ovarian cancer), and NCI-N87 (gastrointestinal tumor derived). GLA exposure led to a dramatic decrease in Her-2/neu promoter activity and a concomitant increase in the levels of polyomavirus enhancer activator 3 (PEA3), a transcriptional repressor of Her-2/neu, in these cell lines. In transient transfection experiments, a Her-2/neu promoter bearing a PEA3 site-mutated sequence was not subject to negative regulation by GLA in Her-2/neu-overexpressing cell lines. Concurrent treatments of Her-2/neu-overexpressing cancer cells with GLA and the anti-Her-2/neu antibody trastuzumab led to synergistic increases in apoptosis and reduced growth and colony formation. J Natl Cancer Inst. 2005 Nov 2;97(21):1611-5. (Menendez JA, et al 2005)

Oleic acid, the main monounsaturated fatty acid of olive oil, suppresses Her-2/neu (erbB-2) expression and synergistically enhances the growth inhibitory effects of trastuzumab (Herceptin) in breast cancer cells with Her-2/neu oncogene amplification.
BACKGROUND: The relationship between the intake of olive oil, the richest dietary source of the monounsaturated fatty acid oleic acid (OA; 18:1n-9), and breast cancer risk and progression has become a controversial issue. Moreover, it has been suggested that the protective effects of olive oil against breast cancer may be due to some other components of the oil rather than to a direct effect of OA. METHODS: Using flow cytometry, western blotting, immunofluorescence microscopy, metabolic status (MTT), soft-agar colony formation, enzymatic in situ labeling of apoptosis-induced DNA double-strand breaks (TUNEL assay analyses), and caspase-3-dependent poly-ADP ribose polymerase (PARP) cleavage assays, we characterized the effects of exogenous supplementation with OA on the expression of Her-2/neu oncogene, which plays an active role in breast cancer etiology and progression. In addition, we investigated the effects of OA on the efficacy of trastuzumab (Herceptin), a humanized monoclonal antibody binding with high affinity to the ectodomain of the Her-2/neu-coded p185(Her-2/neu) oncoprotein. To study these issues we used BT-474 and SKBr-3 breast cancer cells, which naturally exhibit amplification of the Her-2/neu oncogene. RESULTS: Flow cytometric analyses demonstrated a dramatic (up to 46%) reduction of cell surface-associated p185(Her-2/neu) following treatment of the Her-2/neu-overexpressors BT-474 and SK-Br3 with OA. Indeed, this effect was comparable to that found following exposure to optimal concentrations of trastuzumab (up to 48% reduction with 20 microg/ml trastuzumab). Remarkably, the concurrent exposure to OA and suboptimal concentrations of trastuzumab (5 microg/ml) synergistically down-regulated Her-2/neu expression, as determined by flow cytometry (up to 70% reduction), immunoblotting, and immunofluorescence microscopy studies. The nature of the cytotoxic interaction between OA and trastuzumab revealed a strong synergism, as assessed by MTT-based cell viability and anchorage-independent soft-agar colony formation assays. Moreover, OA co-exposure synergistically enhanced trastuzumab efficacy towards Her-2/neu overexpressors by promoting DNA fragmentation associated with apoptotic cell death, as confirmed by TUNEL and caspase-3-dependent PARP cleavage. In addition, treatment with OA and trastuzumab dramatically increased both the expression and the nuclear accumulation of p27(Kip1), a cyclin-dependent kinase inhibitor playing a key role in the onset and progression of Her-2/neu-related breast cancer. Finally, OA co-exposure significantly enhanced the ability of trastuzumab to inhibit signaling pathways downstream of Her-2/neu, including phosphoproteins such as AKT and MAPK. CONCLUSIONS: These findings demonstrate that OA, the main monounsaturated fatty acid of olive oil, suppresses Her-2/neu overexpression, which, in turn, interacts synergistically with anti-Her-2/neu immunotherapy by promoting apoptotic cell death of breast cancer cells with Her-2/neu oncogene amplification. This previously unrecognized property of OA offers a novel molecular mechanism by which individual fatty acids may regulate the malignant behavior of breast cancer cells and therefore be helpful in the design of future epidemiological studies and, eventually, dietary counseling. Ann Oncol. 2005 Mar;16(3):359-71. Epub 2005 Jan 10.(Menendez JA, et al 2005)

Omega-6 polyunsaturated fatty acid gamma-linolenic acid (18:3n-6) enhances docetaxel (Taxotere) cytotoxicity in human breast carcinoma cells: Relationship to lipid peroxidation and HER-2/neu expression.
The omega-6 polyunsaturated fatty acid gamma-linolenic acid (GLA; 18:3n-6) has raised recent interest as novel anti-cancer agent as it possesses effective tumoricidal properties while not inducing damage to normal cells or creating harmful systemic side effects. The taxane docetaxel (Taxotere) is currently one of the most active microtubule-interfering agents for breast cancer. Despite this encouraging therapeutical potential, the clinical use of taxanes involves problems related to the solubility, toxicity and development of drug resistance, which may be partially dependent on the expression of HER-2/neu oncogene. Current trends in the treatment of human tumors are for drug combinations that result in improved responses as well as the ability to use less toxic concentrations of the drugs. Here, we examined the cytotoxic effects of GLA in combination with docetaxel against estrogen-dependent (MCF-7) and estrogen-independent (MDA-MB-231 and SK-Br3) human breast carcinoma cell lines. The cells were exposed simultaneously to GLA and docetaxel or sequentially to GLA followed by docetaxel for 24 h. Cytotoxicity was evaluated by the MTT assay, and the nature of the interactions between GLA and docetaxel (antagonism, additivity, and synergism) was analyzed by median effect and isobologram analyses. Interaction assessment showed that concurrent exposure to GLA plus docetaxel for 24 h resulted in synergism for MCF-7 and MDA-MB-231 cells, whereas an additive effect was observed in SK-Br3 cells. When exposure to GLA (24 and 48 h) was followed sequentially by docetaxel (24 h) a synergistic effect was observed in MDA-MB-231 and SK-Br3 cells, whereas an additive effect was found in MCF-7 cells. GLA-mediated increase in docetaxel cytotoxicity was only marginally abolished by Vitamin E, a lipid peroxidation inhibitor. Moreover, simultaneous exposure to GLA and docetaxel in the presence of the anti-oxidant Vitamin E also resulted in synergism, suggesting a limited influence of the oxidative status of GLA in achieving potentiation of docetaxel-induced cytotoxicity. Further experiments showed that GLA markedly decreased the expression of p185HER-2/neu oncoprotein in MCF-7 breast cancer cells (Therefore, our results show that the fatty acid GLA enhances the cytotoxicity of docetaxel in human breast cancer cells by mechanisms other than lipoperoxidation, and that GLA-induced transcriptional repression of HER-2/neu oncogene might be one component of the mechanisms of this interaction. Oncol Rep. 2004 Jun;11(6):1241-52. (Menendez JA, et al 2004)

Fish Oil, Vit. A, Vit E & Selenium
Efficacy of dietary antioxidants combined with a chemotherapeutic agent on human colon cancer progression in a fluorescent orthotopic mouse model.
We report here the efficacy of dietary antioxidants in combination with chemotherapy on tumor growth in the orthotopic COLO-205-green fluorescent protein (GFP) human colon cancer mouse model. The orthotopically-transplanted nude mice used for the study were randomly divided into 5 groups (A-E) after surgical orthotopic implantation (SOI) of tumor tissue. The following diets were given: Diet A, modified AIN-93M mature rodent diet with 4% fish oil; Diet B, modified AIN-93M which contains added antioxidants vitamin A, vitamin E, and selenium at levels present in the standard AIN-93M diet; Diet C, Diet A without added antioxidants vitamin A, vitamin E, or selenium; Diet D, Diet A with 5 times the amount of added antioxidants vitamin A, vitamin E, and selenium present in Diet B. Cisplatin, 7 mg/kg, was administered intraperitoneally on day 16 after SOI. Throughout the course of treatment, noninvasive whole-body imaging, based on the GFP expression of the tumor, permitted visualization of tumor progression. At sacrifice, the mean tumor weights showed significant statistical differences in all of the treated groups compared to the negative control (no cisplatin treatment) (p <or=0.001). The mean tumor weight showed a significant statistical difference between the Diet D combined with the cisplatin group compared to Diet B combined with cisplatin (p=0.038). Thus, we have demonstrated that Diet D is effective against tumor growth in combination with cisplatin in the fluorescent mouse model of colon cancer COLO-205 GFP. The results of the present study therefore indicate enhancement of cisplatin efficacy by high-dose antioxidants in combination with fish oil for colon cancer progression and suggests the design of clinical trials for this regimen. Anticancer Res. 2009 Jul;29(7):2421-6. (Ma H, et al 2009)

Flaxseed
Flaxseed alone or in combination with tamoxifen inhibits MCF-7 breast tumor growth in ovariectomized athymic mice with high circulating levels of estrogen.
Flaxseed (FS) is rich in mammalian lignan precursors and alpha-linolenic acid, which have been suggested as having anticancer effects. Previous studies have shown that 10% FS inhibits the growth of human estrogen-dependent breast cancer (MCF-7) in athymic mice, and it enhances the inhibitory effect of tamoxifen (TAM). This study determined whether the effect of FS, alone or in combination with TAM, is dose dependent, and it explored the potential mechanism of action. Ovariectomized athymic mice with estradiol (E2) supplementation (1.7 mg/pellet, 60-day release) and established MCF-7 tumors were treated with basal diet control (0FS), 5% FS (5FS), 10% FS (10FS), and TAM (TAM/ 0FS; 5 mg/pellet, 60-day release), alone or in combination (TAM/ 5FS and TAM/10FS) for 8 weeks. Compared with control, 5FS and 10FS significantly inhibited tumor growth by 26% and 38%, respectively. TAM/0FS had an effect similar to the 10FS. TAM/ 5FS and TAM/10FS, respectively, induced significant 48% and 43% reductions in tumor size compared with 0FS, and 18% and 10% reductions compared with TAM/0FS. The relative uterine weight was significantly lower in all TAM groups compared with the control. The reduction of tumor growth resulted from decreased cell proliferation and increased cell apoptosis. TAM/ 5FS caused a significantly higher expression of estrogen receptor-alpha (ERalpha) compared with 5FS and TAM/0FS, whereas TAM/10FS had a higher ERalpha than 10FS and TAM/0FS. Compared with the control, progesterone receptor (PgR) expression was significantly reduced in all treatment groups, but insulin-like growth factor-1 (IGF-1) expression was reduced only by 10FS, TAM/5FS and TAM/10FS. Tumor cell proliferation was significantly positively associated with expression of PgR and IGF-1 and negatively associated with apoptosis and ERalpha. Apoptosis was only associated with ERalpha. In conclusion, FS inhibited MCF-7 tumor growth in a dose-dependent manner and enhanced the inhibitory effect of TAM due to the modulation of ER and growth factor signal transduction pathways. Exp Biol Med (Maywood). 2007 Sep;232(8):1071-80. (Chen J, et al 2007)

Dietary flaxseed enhances the inhibitory effect of tamoxifen on the growth of estrogen-dependent human breast cancer (mcf-7) in nude mice.
PURPOSE: This study determined the effect of 10% dietary flaxseed (FS) and tamoxifen (TAM), alone and in combination, on the growth of estrogen-dependent human breast cancer (MCF-7) in athymic mice with or without 17beta-estradiol (E2) supplementation. EXPERIMENTAL DESIGN: Ovariectomized mice received injection with MCF-7 cells, were implanted with an E2 pellet (1.7 mg), and fed the basal diet (BD). When tumor reached approximately 40 mm2, the E2 implant was removed, and mice were randomized to the following groups and maintained at either low (E2 pellet removed) or high E2 level (new E2 pellet implanted) for 6 weeks: (a) positive control with new E2 pellet, fed BD, (b) negative control with no E2 implant, fed BD, (c) TAM group with TAM pellet (5 mg) implant, fed BD, (d) FS group fed 10% FS, (e) FS+TAM group with TAM implant, fed 10% FS. Tumor growth was monitored weekly. RESULTS: At low E2 level, FS regressed the pretreatment tumor size by 74%. TAM regressed tumor initially but later induced an increase so that the tumor size was finally similar to the pretreatment size. A tumor regression >53% was induced by FS+TAM than by TAM alone. At high E2 level, FS, TAM, and FS+TAM inhibited the tumor growth by 22, 41, and 50%, respectively, compared with the positive control. Decreased tumor size was attributable to reduced tumor cell proliferation and increased apoptosis. CONCLUSIONS: FS inhibited the growth of human estrogen-dependent breast cancer and strengthened the tumor-inhibitory effect of TAM at both low and high E2 levels. Clin Cancer Res. 2004 Nov 15;10(22):7703-11. (Chen J, et al 2004)

Ganoderma lucidum polysaccharides
Effects of water-soluble Ganoderma lucidum polysaccharides on the immune functions of patients with advanced lung cancer.
Preclinical studies have established that the polysaccharide fractions of Ganoderma lucidum have potential antitumor activity. Recent clinical studies have demonstrated that G. lucidum polysaccharides enhance host immune functions [e.g., enhanced natural killer (NK) cell activity] in patients with advanced solid tumors, although an objective response was not observed. This open-label study aimed to evaluate the effects of water-soluble G. lucidum polysaccharides (Ganopoly, Encore International Corp., Auckland, New Zealand) on immune functions in patients with advanced lung cancer. Thirty-six patients were enrolled and treated with 5.4 g/day Ganopoly for 12 weeks. In the 30 cancer patients who completed the trial, treatment with Ganopoly did not significantly alter the mean mitogenic reactivity to phytohemagglutinin, mean counts of CD3, CD4, CD8, and CD56, mean plasma concentrations of interleukin (IL)-2, IL-6, and interferon (IFN)-gamma, or NK activity in the patients, but the results were significantly variable. However, some cancer patients demonstrated markedly modulated immune functions. The changes in IL-1 were correlated with those for IL-6, IFN-gamma, CD3, CD8, and NK activity (P < .05), and IL-2 changes were correlated with those for IL-6, CD8, and NK activity. The results suggest that subgroups of cancer patients might be responsive to Ganopoly in combination with chemotherapy/radiotherapy. Further studies are needed to explore the efficacy and safety of Ganopoly used alone or in combination with chemotherapy-/radiotherapy in lung cancer patients. J Med Food. 2005 Summer;8(2):159-68. (Gao Y, et al 2005)

Ginkgo biloba extract
Ginkgo biloba extract kaempferol inhibits cell proliferation and induces apoptosis in pancreatic cancer cells.
BACKGROUND: Kaempferol is one of the most important constituents in ginkgo flavonoids. Recent studies indicate kaempferol may have antitumor activities. The objective of this study was to determine the effect and mechanisms of kaempferol on pancreatic cancer cell proliferation and apoptosis. MATERIALS AND METHODS: Pancreatic cancer cell lines MIA PaCa-2 and Panc-1 were treated with kaempferol, and the inhibitory effects of kaempferol on pancreatic cancer cell proliferation were examined by direct cell counting, 3H-thymidine incorporation, and MTS assay. Lactate dehydrogenase release from cells was determined as an index of cytotoxicity. Apoptosis was analyzed by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay. RESULTS: Upon the treatment with 70 microm kaempferol for 4 days, MIA PaCa-2 cell proliferation was significantly inhibited by 79% and 45.7% as determined by direct cell counting and MTS assay, respectively, compared with control cells (P < 0.05). Similarly, the treatment with kaempferol significantly inhibited Panc-1 cell proliferation. Kaempferol treatment also significantly reduced 3H-thymidine incorporation in both MIA PaCa-2 and Panc-1 cells. Combination treatment of low concentrations of kaempferol and 5-fluorouracil showed an additive effect on the inhibition of MIA PaCa-2 cell proliferation. Furthermore, kaempferol had significantly less cytotoxicity than 5-fluorouracil in normal human pancreatic ductal epithelial cells (P = 0.029). In both MIA PaCa-2 and Panc-1 cells, apoptotic cell population was increased when treated with kaempferol in a concentration-dependent manner. CONCLUSIONS: Ginkgo biloba extract kaempferol effectively inhibits pancreatic cancer cell proliferation and induces cancer cell apoptosis, which may sensitize pancreatic tumor cells to chemotherapy. Kaempferol may have clinical applications as adjuvant therapy in the treatment of pancreatic cancer. J Surg Res. 2008 Jul;148(1):17-23. Epub 2008 Mar 26. (Zhang Y, et al 2008)

Ginseng
Association of ginseng use with survival and quality of life among breast cancer patients.
The authors evaluated the associations of ginseng use as a complementary therapy with survival and quality of life (QOL) in a cohort of 1,455 breast cancer patients who were recruited to the Shanghai Breast Cancer Study between August 1996 and March 1998 in Shanghai, China. Patients were followed through December 2002. Information on ginseng use before cancer diagnosis was collected at baseline recruitment and was linked to survival. Survivors’ ginseng use after cancer diagnosis was obtained at the follow-up survey and was correlated to QOL at the same time. The Kaplan-Meier method and Cox regression models were applied to evaluate the association of ginseng use with overall and disease-free survival. The relation of ginseng use and QOL was evaluated by using multiple linear regression models. Approximately 27% of study participants were regular ginseng users before cancer diagnosis. Compared with patients who never used ginseng, regular users had a significantly reduced risk of death; adjusted hazard ratios associated with ginseng use were 0.71 (95% confidence interval: 0.52, 0.98) for total mortality and 0.70 (95% confidence interval: 0.53, 0.93) for disease-specific mortality/recurrence. Ginseng use after cancer diagnosis, particularly current use, was positively associated with QOL scores, with the strongest effect in the psychological and social well-being domains. Additionally, QOL improved as cumulative ginseng use increased. Am J Epidemiol. 2006 Apr 1;163(7):645-53. Epub 2006 Feb 16.(Cui Yet al 2006)

Grape seed extract
Synergistic anti-cancer effects of grape seed extract and conventional cytotoxic agent doxorubicin against human breast carcinoma cells.
With an approach to enhance the efficacy of chemotherapy agents against breast cancer treatment, here, we investigated the anti-cancer effects of grape seed extract (GSE) and doxorubicin (Dox), either alone or in combination, in estrogen receptor-positive MCF-7 and receptor-negative MDA-MB468 human breast carcinoma cells. GSE (25-200 micro g/ml) treatment of cells resulted in 16-72% growth inhibition and 9-33% cell death, in a dose- and a time-dependent manner. In other studies, Dox (10-100 nM) treatment showed 23-96% growth inhibition and 10-55% cell death. Based on these results, several combinations of GSE (25-100 micro g/ml) with Dox (10-75 nM) were next assessed for their synergistic, additive and/or antagonistic efficacy towards cell growth inhibition and death. In both MCF-7 and MDA-MB468 cells, a combination of 100 micro g/ml GSE with 25-75 nM Dox treatment for 48 h showed a strong synergistic effect [combination index (CI) < 0.5] in cell growth inhibition, but mostly an additive effect (CI approximately 1) in cell death. In cell-cycle progression studies, GSE plus Dox combination resulted in a moderate increase in G1 arrest in MCF-7 cells compared to each agent alone. GSE plus Dox combination showed a very strong and significant G1 arrest in MDA-MB468 cells when compared with Dox alone, however, it was less than that observed with GSE alone. In quantitative apoptosis studies, GSE and Dox alone and in combination showed comparable apoptotic death of MCF-7 cells, however, a combination of the two was inhibitory to Dox induced apoptosis in MDA-MB468 cells. This was further confirmed in another estrogen receptor-negative MDA-MB231 cell line, in which GSE and Dox combination strongly inhibited cell growth but did not show any increase in apoptotic cell death caused by Dox. Together, these results suggest a strong possibility of synergistic efficacy of GSE and Dox combination for breast cancer treatment, independent of estrogen receptor status of the cancer cell. Breast Cancer Res Treat. 2004 May;85(1):1-12. (Sharma G,et al 2004)

Grape seed proanthocyanidinProtective effect of grape seed proanthocyanidin extract against oxidative stress induced by cisplatin in rats.
Cisplatin is one of the most potent chemotherapeutic antitumor drugs. Oxidative stress has been proven to be involved in cisplatin induced toxicity. Therefore, the present study was undertaken to examine the antioxidant potential of grape seed proanthocyanidin extract (GSPE) against the toxicity of cisplatin in male rats. Cisplatin treated animals revealed a significant elevation in plasma, heart, kidney and liver thiobarbituric acid-reactive substances (TBARS), while the activities of antioxidant enzymes (GST, SOD, CAT and GSH-Px, and the levels of glutathione (GSH) were decreased. Aspartate and alanine transaminases (AST and ALT), creatine kinase and lactate dehydrogenase were significantly increased in plasma, while liver AST and ALT were significantly decreased. Cisplatin significantly increased the levels of plasma total lipid, cholesterol, urea and creatinine, and the relative weight of kidney. On the other hand, plasma total protein and albumin, and body weight were significantly decreased. GSPE reduced cisplatin induced the levels of TBARS in plasma, heart, kidney and liver, TL, cholesterol, urea and creatinine, and liver AST and ALT. Moreover, it ameliorated cisplatin-induced decrease in the activities of antioxidant enzymes, and GSH, total protein and albumin. Therefore, the present results revealed that GSPE exerts a protective effect by antagonizing cisplatin toxicity. Food Chem Toxicol. 2009 Feb 10. [Epub ahead of print] (Yousef MISaad AAEl-Shennawy LK. 2009)

Green and Black TeaTea consumption and ovarian cancer risk in a population-based cohort.
BACKGROUND: Substantial evidence from laboratory studies indicates that green and black tea preparations may protect against various cancers. Few epidemiologic studies, however, have examined the relationship specifically between tea consumption and risk of ovarian cancer. METHODS: We prospectively examined the association between tea consumption and risk of ovarian cancer in 61,057 women aged 40 to 76 years who were participants in the population-based Swedish Mammography Cohort. Participants completed a validated 67-item food frequency questionnaire at enrollment between 1987 and 1990 and were followed for cancer incidence through December 2004. RESULTS: During an average follow-up of 15.1 years, 301 incident cases of invasive epithelial ovarian cancer were ascertained. Tea consumption was inversely associated with the risk of ovarian cancer after controlling for potential confounders (P for trend, .03). Compared with women who never or seldom (less than monthly) consumed tea, the multivariate hazard ratios for those who consumed less than 1 cup per day, 1 cup per day, and 2 or more cups per day were 0.82 (95% confidence interval [CI], 0.62-1.08), 0.76 (95% CI, 0.56-1.04), and 0.54 (95% CI, 0.31-0.91), respectively. Each additional cup of tea per day was associated with an 18% lower risk of ovarian cancer (multivariate hazard ratio, 0.82; 95% CI, 0.68-0.99). CONCLUSION: These results suggest that tea consumption is associated with a reduced risk of epithelial ovarian cancer in a dose-response manner. Arch Intern Med. 2005 Dec 12-26;165(22):2683-6. (Larsson SCWolk A.2005)

Green Tea (EGCG)Epigallocatechin-gallate modulates chemotherapy-induced apoptosis in human cholangiocarcinoma cells.
BACKGROUND: Green tea polyphenols are chemopreventive in several cancer models but their use as adjunctive therapeutic agents for cancer is unknown. AIMS: Cholangiocarcinomas respond poorly to chemotherapeutic agents and our aims were to assess the utility of green tea polyphenols as adjuncts to chemotherapy for cholangiocarcinoma. MATERIALS AND METHODS: We assessed the effect of purified green tea catechins on chemotherapy-induced apoptosis in KMCH, CC-LP-1 and Mz-ChA-1 human cholangiocarcinoma cells, and on chemosensitivity of Mz-ChA-1 cell xenografts in nude mice. RESULTS: Epigallocatechin-gallate (EGCG), but not the structurally related catechin epigallocatechin, sensitized cells to apoptosis induced by gemcitabine (GEM), mitomycin C or 5-fluorouracil in vitro. Mitochondrial membrane depolarization, cytosolic cytochrome c expression and apoptosis were increased in cells incubated with EGCG and GEM compared with either agent alone. Furthermore, EGCG decreased in vivo growth and increased the sensitivity to GEM of Mz-ChA-1 cell xenografts in nude mice. CONCLUSIONS: The green tea polyphenol EGCG sensitizes human cholangiocarcinoma cells to chemotherapy-induced apoptosis and warrants evaluation as an adjunct to chemotherapy for the treatment of human cholangiocarcinoma. Liver Int. 2009 May;29(5):670-7. Epub 2009 Feb 17. (Lang M, et al 2009)

Green Tea
Green tea consumption enhances survival of epithelial ovarian cancer.
Our study investigates whether tea consumption can enhance the survival of patients with epithelial ovarian cancer, a prospective cohort study was conducted in Hangzhou, China. The cohort comprised 254 patients recruited during 1999-2000 with histopathologically confirmed epithelial ovarian cancer and was followed up for a minimum of 3 years. Two hundred forty four (96.1%) of the cohort or their close relatives were traced. The variables examined included their survival time and the frequency and quantity of tea consumed post-diagnosis. The actual number of deaths was obtained and Cox proportional hazards models were used to obtain hazard ratios and associated 95% confidence intervals (CI), adjusting for age at diagnosis, locality, BMI, parity, FIGO stage, histologic grade of differentiation, cytology of ascites, residual tumour and chemotherapeutic status. The survival experience was different between tea drinkers and non-drinkers (p < 0.001). There were 81 (77.9%) of 104 tea-drinkers who survived to the time of interview, compared to only 67 women (47.9%) still alive among the 140 non-drinkers. Compared to non-drinkers, the adjusted hazard ratios were 0.55 (95% CI = 0.34-0.90) for tea-drinkers, 0.43 (95% CI = 0.20-0.92) for consuming at least 1 cup of green tea/day, 0.44 (95% CI = 0.22-0.90) for brewing 1 batch or more of green tea/day, 0.40 (95% CI = 0.18-0.90) for consuming more than 500 g of dried tea leaves/year, and 0.38 (95% CI = 0.15-0.97) for consuming at least 2 g of dried tea leaves/batch. The corresponding dose-response relationships were significant (p < 0.05). We conclude that increasing the consumption of green tea post-diagnosis may enhance epithelial ovarian cancer survival. Int J Cancer. 2004 Nov 10;112(3):465-9. (Zhang M, et al 2004)

Chemoprevention of human prostate cancer by oral administration of green tea catechins in volunteers with high-grade prostate intraepithelial neoplasia: a preliminary report from a one-year proof-of-principle study.
Green tea catechins (GTCs) proved to be effective in inhibiting cancer growth in several experimental models. Recent studies showed that 30% of men with high-grade prostate intraepithelial neoplasia (HG-PIN) would develop prostate cancer (CaP) within 1 year after repeated biopsy. This prompted us to do a proof-of-principle clinical trial to assess the safety and efficacy of GTCs for the chemoprevention of CaP in HG-PIN volunteers. The purity and content of GTCs preparations were assessed by high-performance liquid chromatography [(-)-epigallocathechin, 5.5%; (-)-epicatechin, 12.24%; (-)-epigallocatechin-3-gallate, 51.88%; (-)-epicatechin-3-gallate, 6.12%; total GTCs, 75.7%; caffeine, <1%]. Sixty volunteers with HG-PIN, who were made aware of the study details, agreed to sign an informed consent form and were enrolled in this double-blind, placebo-controlled study. Daily treatment consisted of three GTCs capsules, 200 mg each (total 600 mg/d). After 1 year, only one tumor was diagnosed among the 30 GTCs-treated men (incidence, approximately 3%), whereas nine cancers were found among the 30 placebo-treated men (incidence, 30%). Total prostate-specific antigen did not change significantly between the two arms, but GTCs-treated men showed values constantly lower with respect to placebo-treated ones. International Prostate Symptom Score and quality of life scores of GTCs-treated men with coexistent benign prostate hyperplasia improved, reaching statistical significance in the case of International Prostate Symptom Scores. No significant side effects or adverse effects were documented. To our knowledge, this is the first study showing that GTCs are safe and very effective for treating premalignant lesions before CaP develops. As a secondary observation, administration of GTCs also reduced lower urinary tract symptoms, suggesting that these compounds might also be of help for treating the symptoms of benign prostate hyperplasia. Cancer Res. 2006 Jan 15;66(2):1234-40. (Bettuzzi S, et al 2006)

Green Tea and Lycopene
Tea and lycopene protect against prostate cancer.
Prostate cancer is the most common male cancer in developed countries and is increasing in the developing world. Its long latency and geographical variation suggest the possibility of prevention or postponement of onset by dietary modification. To investigate the possible joint effect of lycopene and green tea on prostate cancer risk, a case-control study was conducted in Hangzhou, China, with 130 prostate cancer patients and 274 hospital controls. Information on tea and dietary intakes, and possible confounders was collected using a structured questionnaire. The risk of prostate cancer for the intake of tea and lycopene and their joint effect were assessed using multivariate logistic regression models. Prostate cancer risk was reduced with increased consumption of green tea. The protective effect of green tea was significant (odds ratio 0.14, 95% CI: 0.06-0.35) for the highest quartile relative to the lowest after adjusting for total vegetables and fruits intakes and other potential confounding factors. Intakes of vegetables and fruits rich in lycopene were also inversely associated with prostate cancer risk (odds ratio 0.18, 95% CI 0.08-0.39). Interaction analysis showed that the protective effect from tea and lycopene consumption was synergistic (p<0.01). This study suggests that habitual drinking tea and intakes of vegetables and fruits rich in lycopene could lead to a reduced risk of prostate cancer in Chinese men. Together they have a stronger preventive effect than either component taken separately. This is the first epidemiological study to investigate the joint effect between tea drinking and lycopene intake. Asia Pac J Clin Nutr. 2007;16 Suppl 1:453-7. (Jian LLee AHBinns CW.2007)

Honokiol
The natural product honokiol induces caspase-dependent apoptosis in B-cell chronic lymphocytic leukemia (B-CLL) cells.
B-cell chronic lymphocytic leukemia (B-CLL) remains an incurable disease that requires innovative new approaches to improve therapeutic outcome. Honokiol is a natural product known to possess potent antineoplastic and antiangiogenic properties. We examined whether honokiol can overcome apoptotic resistance in primary tumor cells derived from B-CLL patients. Honokiol induced caspase-dependent cell death in all of the B-CLL cells examined and was more toxic toward B-CLL cells than to normal mononuclear cells, suggesting greater susceptibility of the malignant cells. Honokiol-induced apoptosis was characterized by the activation of caspase-3, -8, and -9 and cleavage of poly(adenosine diphosphate-ribose) polymerase (PARP). Exposure of B-CLL cells to honokiol resulted in up-regulation of Bcl2-associated protein (Bax) and down-regulation of the expression of the key survival protein myeloid-cell leukemia sequence 1 (Mcl-1), which is associated with response to treatment in B-CLL patients. In addition, B-CLL cells pretreated with interleukin-4 (IL-4), a cytokine known to support B-CLL survival, underwent apoptosis when subsequently incubated with honokiol, indicating that honokiol could also overcome the prosurvival effects of IL-4. Furthermore, honokiol enhanced cytotoxicity induced by fludarabine, cladribine, or chlorambucil. These data indicate that honokiol is a potent inducer of apoptosis in B-CLL cells and should be examined for further clinical application either as a single agent or in combination with other anticancer agents. Blood. 2005 Jul 15;106(2):690-7. Epub 2005 Mar 31. (Battle TEArbiser JFrank DA. 2005)

Honokiol induces calpain-mediated glucose-regulated protein-94 cleavage and apoptosis in human gastric cancer cells and reduces tumor growth.
BACKGROUND: Honokiol, a small molecular weight natural product, has been shown to possess potent anti-neoplastic and anti-angiogenic properties. Its molecular mechanisms and the ability of anti-gastric cancer remain unknown. It has been shown that the anti-apoptotic function of the glucose-regulated proteins (GRPs) predicts that their induction in neoplastic cells can lead to cancer progression and drug resistance. We explored the effects of honokiol on the regulation of GRPs and apoptosis in human gastric cancer cells and tumor growth. METHODOLOGY AND PRINCIPAL FINDINGS: Treatment of various human gastric cancer cells with honokiol led to the induction of GRP94 cleavage, but did not affect GRP78. Silencing of GRP94 by small interfering RNA (siRNA) could induce cell apoptosis. Treatment of cells with honokiol or chemotherapeutics agent etoposide enhanced the increase in apoptosis and GRP94 degradation. The calpain activity and calpain-II (m-calpain) protein (but not calpain-I (micro-calpain)) level could also be increased by honokiol. Honokiol-induced GRP94 down-regulation and apoptosis in gastric cancer cells could be reversed by siRNA targeting calpain-II and calpain inhibitors. Furthermore, the results of immuno-fluorescence staining and immunoprecipitation revealed a specific interaction of GRP94 with calpain-II in cells following honokiol treatment. We next observed that tumor GRP94 over-expression and tumor growth in BALB/c nude mice, which were inoculated with human gastric cancer cells MKN45, are markedly decreased by honokiol treatment. CONCLUSIONS AND SIGNIFICANCE: These results provide the first evidence that honokiol-induced calpain-II-mediated GRP94 cleavage causes human gastric cancer cell apoptosis. We further suggest that honokiol may be a possible therapeutic agent to improve clinical outcome of gastric cancer. PLoS One. 2007 Oct 31;2(10):e1096. (Sheu MLLiu SHLan KH.2007)

Licorice extract
Licorice preparations improve efficiency of chemotherapy and surgical treatment of transplanted tumors.
Experiments on animals with Lewis lung carcinoma and Ehrlich tumor showed that licorice (glycyrrhiza) extract and glyciram prepared from this plant improved the antitumor effect ofcyclophosphamide. Glyciram reduced the toxic effect of the cytostatic on peripheral blood leukocytes. Licorice extract inhibited the growth of Ehrlich tumor and development of metastases in mice with Lewis lung carcinoma. Glyciram administered to mice after removal of Lewis lung carcinoma produced an antimetastatic effect and prevented relapses. Bull Exp Biol Med. 2008 Feb;145(2):252-5.(Gol’dberg ED, et al 2008)

Effect of a combination of extract from several plants on cell-mediated and humoral immunity of patients with advanced ovarian cancer.
The influence of a plant preparation AdMax (Nulab Inc., Clearwater, FL, USA) on immunity in ovarian cancer patients was studied. The preparation is a combination of dried ethanol/water extracts from roots of Leuzea carthamoides, Rhodiola rosea, Eleutherococcus senticosus and fruits of Schizandra chinensis. Twenty eight patients with stage III-IV epithelial ovarian cancer were treated once with 75 mg/m(2) cisplatin and 600 mg/m(2) cyclophosphamide. Peripheral blood was collected 4 weeks after the chemotherapy. Subclasses of T, B and NK lymphocytes were tested for in the blood samples: CD3, CD4, CD5, CD7, CD8, CD11B, CD16, CD20, CD25, CD38, CD45RA, CD50, CD71 and CD95. Immunoglobulin G, A and M concentrations were also determined. Changes were observed in the following T cell subclasses: CD3, CD4, CD5 and CD8. In patients who took AdMax (270 mg a day) for 4 weeks following the chemotherapy, the mean numbers of the four T cell subclasses were increased in comparison with the mean numbers of the T cell subclasses in patients who did not take AdMax. In patients who took AdMax, the mean amounts of IgG and IgM were also increased. The obtained results suggest that the combination of extracts from adaptogenic plants may boost the suppressed immunity in ovarian cancer patients who are subject to chemotherapy. Phytother Res. 2006 May;20(5):424-5. (Kormosh NLaktionov KAntoshechkina M.2006)

Cytotoxic effect of mistletoe (Viscum album L.) extract on Jurkat cells and its interaction with doxorubicin.
Mistletoe preparations are frequently used by cancer patients because of their ability to stimulate the immunity and to improve the quality of life. Moreover mistletoe and its active substances (especially lectins) possess cytotoxic effect on various cancer cell lines. However, only little is known about its interaction with anticancer drugs. Therefore the cytotoxic and apoptosis-inducing effects of aqueous mistletoe extract (VA) and its interaction with doxorubicin (DOXO) were investigated in Jurkat cells.The results show that VA extract as well as DOXO exert cytotoxic effects on Jurkat cells in a dose-dependent manner. Cytotoxicity of DOXO was much stronger (LC(50) = 11.68 ng/mL) than that of VA extract (LC(50) = 35.67 mug/mL). Their combination led to synergism only at those concentrations that were highly cytotoxic alone. Both substances (alone and in combination) induced DNA fragmentation in Jurkat cells. In conclusion, an aqueous extract prepared from mistletoe tops exerted cytotoxic and apoptosis-inducing effects on Jurkat cells alone as well as in combination with DOXO. Phytother Res. 2009 Jul 16. [Epub ahead of print] (Sabová L, et al 2009)

Comparison of Viscum album QuFrF extract with vincristine in an in vitro model of human B cell lymphoma WSU-1.
Viscum album L. extract (Iscador) with different preparations is used either alone or in combination with chemo/radiotherapy in the treatment of patients with various tumours. Vincristine (CAS 57-22-7) as a chemotherapeutic agent is used mainly in combination with other chemotherapeutic substances in the therapy of B cell lymphoma. In this study, the effects of Viscum album (VA) QuFrF extract and vincristine were compared on B cell lymphoma cell line WSU-1 in an in vitro model. As parameters were measured: proliferation, viability, apoptosis/necrosis, IL-6 production, DNA synthesis and the cell cycle phases of the lymphoma cells at various time points. RESULTS: The cytostatic (inhibition of proliferation) effects ofVAQuFrF and vincristine at 10 microg/10(5) cells were the same at 48 h and 72 h. This means that the anti-proliferative effect of 2 ng lectin (in 10 microg extract) is equivalent to 10 microg of vincristine. There was a relationship between the cytostatic and cytocidal (killing of viable cells) effects for both substances. This means that both substances first inhibit the proliferation of the tumour cells, and then the cells die by apoptosis or necrosis. VAQuFrF and vincristine reduced the DNA synthesis markedly and arrested the G2/M cell cycle phase. Both substances led to a clearly dose-dependent apoptosis at 12 h and 24 h. Neither VAQuFrF nor vincristine led to IL-6 production of the lymphoma cells. CONCLUSION: The effects of VAQuFrF on the B cell lymphoma cell line WSU-1 were comparable to those of vincristine in all parameters. The effective dose range lay between 50 and 100 microg/10(6) cells for VAQuFrF, for vincristine it was somewhat lower. Arzneimittelforschung. 2008;58(11):592-7.(Kovacs ELink SToffol-Schmidt U. 2008)

Notoginseng enhances anti-cancer effect of 5-fluorouracil on human colorectal cancer cells.
PURPOSE: Panax notoginseng is a commonly used Chinese herb. Although a few studies have found that notoginseng shows anti-tumor effects, the effect of this herb on colorectal cancer cells has not been investigated. 5-Fluorouracil (5-FU) is a chemotherapeutic agent for the treatment of colorectal cancer that interferes with the growth of cancer cells. However, this compound has serious side effects at high doses. In this study, using HCT-116 human colorectal cancer cell line, we investigated the possible synergistic anti-cancer effects between notoginseng flower extract (NGF)and 5-FU on colon cancer cells. METHODS: The anti-proliferation activity of these modes of treatment was evaluated by MTS cell proliferation assay. Apoptotic effects were analyzed by using Hoechst 33258 staining and Annexin-V/PI staining assays. The anti-proliferation effects of four major single compounds from NGF, ginsenosides Rb1, Rb3, Rc and Rg3 were also analyzed. RESULTS: Both 5-FU and NGF inhibited proliferation of HCT-116 cells. With increasing doses of 5-FU, the anti-proliferation effect was slowly increased. The combined usage of 5-FU 5 microM and NGF 0.25 mg/ml, significantly increased the anti-proliferation effect (59.4 +/- 3.3%) compared with using the two medicines separately (5-FU 5 microM, 31.1 +/- 0.4%; NGF 0.25 mg/ml, 25.3 +/- 3.6%). Apoptotic analysis showed that at this concentration, 5-FU did not exert an apoptotic effect, while apoptotic cells induced by NGF were observed, suggesting that the anti-proliferation target(s) of NGF may be different from that of 5-FU, which is known to inhibit thymidilate synthase. CONCLUSIONS: This study demonstrates that NGF can enhance the anti-proliferation effect of 5-FU on HCT-116 human colorectal cancer cells and may decrease the dosage of 5-FU needed for colorectal cancer treatment. Cancer Chemother Pharmacol. 2007 Jun;60(1):69-79. Epub 2006 Sep 29. (Wang CZ, et al 2007)

Panaxadiol
Panaxadiol, a purified ginseng component, enhances the anti-cancer effects of 5-fluorouracil in human colorectal cancer cells.
PURPOSE: Colorectal cancer is a major cause of morbidity and mortality for cancer worldwide. Although 5-fluorouracil (5-FU) is one of the most widely used chemotherapeutic agents in first-line therapy for colorectal cancer, serious side effects limit its clinical usefulness. Panaxadiol (PD) is the purified sapogenin of ginseng saponins, which exhibit anti-tumor activity. In this study, we investigated the possible synergistic anti-cancer effects of PD and 5-FU on a human colorectal cancer cell line, HCT-116. METHODS: Cell viability was evaluated by an MTS cell proliferation assay. Morphological observation was performed by crystal violet cell viability staining assay. Cell cycle distribution and apoptotic effects were analyzed by flow cytometry after staining with PI/RNase or Annexin V/PI. RESULTS: Cell growth was markedly suppressed in HCT-116 cells treated by 5-FU (20-100 microM) for 24 or 48 h with time-dependent effects. The significant suppression on HCT-116 cell proliferation was observed after treatment with PD (25 microM) for 24 and 48 h. Panaxadiol (25 microM) markedly (P < 0.05) enhanced the anti-proliferative effects of 5-FU (5, 10, 20 microM) on HCT-116 cells compared to single treatment of 5-FU for 24 and 48 h. Flow cytometric analysis on DNA indicated that PD and 5-FU selectively arrested cell cycle progression in the G1 phase and S phase (P < 0.01), respectively, compared to the control condition. Combination use of 5-FU with PD significantly (P < 0.001) increased cell cycle arrest in the S phase compared to that treated by 5-FU alone. The combination of 5-FU and PD significantly enhanced the percentage of apoptotic cells when compared with the corresponding cell groups treated by 5-FU alone (P < 0.001). CONCLUSIONS: Panaxadiol enhanced the anti-cancer effects of 5-FU on human colorectal cancer cells through the regulation of cell cycle transition and the induction of apoptotic cells. Cancer Chemother Pharmacol. 2009 Nov;64(6):1097-104. Epub 2009 Mar 11. (Li XLWang et al 2009)

Chemopreventive effects of Panax notoginseng and its major constituents on SW480 human colorectal cancer cells.
In this study, we evaluated the effects of Panax notoginseng root extract (NGRE) and its major constituents on SW480 human colorectal cancer cells. We used high performance liquid chromatography to determine the contents of major saponins in NGRE. The anti-proliferative effects were evaluated by the cell counting method, and concentration-related anti-proliferative effects were observed. At 1.0 mg/ml, NGRE inhibited cell growth by 85.8% (P<0.01), probably linked to the higher concentration of ginsenosides Rb1 and Rg1. The pharmacologic activities of notoginsenoside R1 and ginsenosides Rg1 and Rb1 on the cells were antiproliferative. We tested the effects of NGRE on DNA synthesis by measuring [3H]-thymidine incorporation. NGRE induced cell apoptosis at 0.5 and 1 mg/ml. Two-day treatment with 300 microM of notoginsenoside R1, ginsenosides Rg1 and Rb1 increased cell apoptosis significantly. Cell cycle and cyclin A assay showed that NGRE arrested cells in the synthesis phase and increased the expression of cyclin A remarkably. NGRE also enhanced the actions of two chemotherapeutic agents, 5-fluorouracil and irinotecanCell growth decreased more with the combined treatment of NGRE and 5-fluorouracil (or irinotecan) than with the chemotherapy agent applied alone, suggesting that notoginseng can reduce the dose of 5-fluorouracil (or irinotecan) needed to achieve desired effects. Further in vivo and human trials are warranted to test whether notoginseng is a valuable chemo-adjuvant with clinical validity. Int J Oncol. 2007 Nov;31(5):1149-56. (Wang CZ, et al 2007)

Parthenolide and sulindac cooperate to mediate growth suppression and inhibit the nuclear factor-kappa B pathway in pancreatic carcinoma cells.
Activation of the transcription factor nuclear factor-kappa B (NF-kappa B) has been implicated in pancreatic tumorigenesis. We evaluated the effect of a novel NF-kappa B inhibitor, parthenolide, a sesquiterpene lactone isolated from the herb feverfew, in three human pancreatic tumor cell lines (BxPC-3, PANC-1, and MIA PaCa-2). Parthenolide inhibited pancreatic cancer cell growth in a dose-dependent manner with substantial growth inhibition observed between 5 and 10 micromol/L parthenolide in all three cell lines. Parthenolide treatment also dose-dependently increased the amount of the NF-kappa B inhibitory protein, I kappa B-alpha, and decreased NF-kappa B DNA binding activity. We have previously shown that nonsteroidal anti-inflammatory drugs (NSAID) suppress the growth of pancreatic cancer cells. To determine whether inhibition of the NF-kappa B pathway by parthenolide could sensitize pancreatic cancer cells to NSAID inhibition, BxPC-3, PANC-1, and MIA PaCa-2 cells were treated with parthenolide and the NSAID sulindac, either alone or in combination. Treatment with the combination of parthenolide and sulindac inhibited cell growth synergistically in MIA PaCa-2 and BxPC-3 cells and additively in PANC-1 cells. In addition, treatment with the parthenolide/sulindac combination lowered the threshold for apoptosis. Increased levels of I kappa B-alpha protein were detected, especially in MIA PaCa-2 cells, after treatment with parthenolide and sulindac compared with each agent alone. Similarly, decreased NF-kappa B DNA binding and transcriptional activities were detected in cells treated with the combination compared with the single agents, demonstrating cooperative targeting of the NF-kappa B pathway. These data provide preclinical support for a combined chemotherapeutic approach with NF-kappa B inhibitors and NSAIDs for the treatment of pancreatic adenocarcinoma. Mol Cancer Ther. 2005 Apr;4(4):587-94.(Yip-Schneider MT, et al 2005)

Parthenolide cooperates with NS398 to inhibit growth of human hepatocellular carcinoma cells through effects on apoptosis and G0-G1 cell cycle arrest.
Chemotherapy to date has not been effective in the treatment of human hepatocellular carcinoma. More effective treatment strategies may involve combinations of agents with activity against hepatocellular carcinoma. Parthenolide, a nuclear factor-kappaB (NF-kappaB) inhibitor, and NS398, a cyclooxygenase (COX)-2 inhibitor, have been shown to individually suppress the growth of hepatocellular carcinoma cells in vitro. To investigate their effects in combination, three human hepatocellular carcinoma lines (Hep3B, HepG2, and PLC) were treated with parthenolide and/or NS398. Parthenolide (0.1-10 micromol/L) and NS398 (1-100 micromol/L) each caused concentration-dependent growth inhibition in all cell lines. The addition of parthenolide to NS398 reduced the concentration of NS398 required to inhibit hepatocellular carcinoma growth. Because parthenolide and COX-2 inhibitors have been reported to influence NF-kappaB activity, the effects on this pathway were investigated. The combination of parthenolide/NS398 inhibited phosphorylation of the NF-kappaB-inhibitory protein IkappaBalpha and increased total IkappaBalpha levels. NF-kappaB DNA-binding and transcriptional activities were inhibited more by the combination than the single agents in Hep3B and HepG2 cells but not in PLC cells. The response of PLC cells to NS398 was augmented by p65 small interfering RNA to inhibit NF-kappaB p65 protein expression. The combination of parthenolide/NS398 increased apoptosis only in PLC cells, suggesting that the combination may decrease the apoptotic threshold in these cells. In Hep3B and HepG2 cells, combination treatment with NS398/parthenolide altered the cell cycle distribution resulting in more G0-G1 accumulation. Cyclin D1 levels were further decreased by combination treatment in all cell lines, correlating with the cell cycle alterations. Our results suggest that parthenolide may be effective in combination with COX-2 inhibitors for the treatment of hepatocellular carcinoma. Mol Cancer Res. 2006 Jun;4(6):387-99. (Ralstin MC, et al 2006)

The nuclear factor kappa B inhibitor parthenolide restores ICI 182,780 (Faslodex; fulvestrant)-induced apoptosis in antiestrogen-resistant breast cancer cells.
The molecular mechanisms underlying the acquisition of resistance to the antiestrogen Faslodex are poorly understood, although enhanced expression and activity of nuclear factor kappaB (NFkappaB) have been implicated as a critical element of this phenotype. The purpose of this study was to elucidate the mechanism by which NFkappaB up-regulation contributes to Faslodex resistance and to determine whether pharmacologic inhibition of NFkappaB by the small molecule parthenolide could restore Faslodex-mediated suppression of cell growth. Basal expression of multiple NFkappaB-related molecules in MCF7-derived LCC1 (antiestrogen-sensitive) and LCC9 (antiestrogen-resistant) breast cancer cells was determined, and cells were treated with Faslodex or parthenolide. The effect of these drugs either singly or in combination was assessed by cell proliferation, estrogen receptor (ER)-dependent transcriptional activation, cell cycle analysis, and apoptosis assays. Expression of the p65 NFkappaB subunit and the upstream NFkappaB regulator IkappaB kinase gamma/NFkappaB essential modulator were increased in the resistant MCF7/LCC9 cells (P=0.001 and 0.04, respectively). Whereas MCF7/LCC9 cells were unresponsive to Faslodex alone, parthenolide effectively inhibited MCF7/LCC9 cell proliferation and the combination of Faslodex and parthenolide resulted in a 4-fold synergistic reduction in cell growth (P=0.03). This corresponded to a restoration of Faslodex-induced apoptosis (P=0.001), with no observable changes in ER-dependent transcription or cell cycle phase distribution. Because parthenolide has shown safety in Phase I clinical trials, these findings have direct clinical relevance and provide support for the design of clinical studies combining antiestrogens and parthenolide in ER-positive breast cancer. Mol Cancer Ther. 2005 Jan;4(1):33-41. (Riggins RB, et al 2005)

Protein and Ginger
Protein and ginger for the treatment of chemotherapy-induced delayed nausea.
BACKGROUND: Nausea that develops during the period that begins 24 hours after the administration of chemotherapy is called delayed nausea, and occurs in many patients with cancer. Meals high in protein decrease the nausea of motion sickness and pregnancy, possibly by reducing gastric dysrhythmias. Ginger also has antinausea properties. OBJECTIVES: To explore the use of protein meals with ginger for the treatment of the delayed nausea of chemotherapy. DESIGN: Twenty-eight (28) patients with cancer receiving chemotherapy for the first time were assigned to 1 of 3 groups. For 3 days beginning the day after their chemotherapy, Control Group patients continued with their normal diet, Protein Group patients consumed a protein drink and ginger twice daily, and High Protein Group patients consumed a protein drink with additional protein and ginger twice daily. OUTCOME MEASURES: Patients recorded in a diary each day whether they had experienced nausea, whether their nausea had been frequent, whether their nausea had been bothersome, and whether they had needed any antiemetic medication. Gastric myoelectrical activity was assessed in 5 patients before and after ingestion of a high protein meal and ginger. RESULTS: Reports of nausea, frequent nausea, and bothersome nausea were significantly less common among High Protein Group patients than among Control and Protein Group patients. Furthermore, significantly fewer patients in the High Protein Group used antiemetic medication. Differences between the Protein and Control groups were not statistically significant. In the 5 patients who had tests of gastric myoelectrical activity performed, a significant decrease in gastric dysrhythmia occurred after ingestion of the protein and ginger. CONCLUSIONS: High protein meals with ginger reduced the delayed nausea of chemotherapy and reduced use of antiemetic medications. Protein with ginger holds the potential of representing a novel, nutritionally based treatment for the delayed nausea of chemotherapy. J Altern Complement Med. 2008 Jun;14(5):545-51. (Levine ME, et al 2008)

Quercetin
Quercetin greatly improved therapeutic index of doxorubicin against 4T1 breast cancer by its opposing effects on HIF-1alpha in tumor and normal cells.PURPOSE: The anthracycline antibiotic doxorubicin (DOX) has been used successfully for treating various types of cancers. However, the therapeutic efficacy of DOX was greatly restricted by its cumulative dose-related cardiotoxicity and common side effects such as bone marrow and immune suppression. Quercetin had better cardioprotective and hepatoprotective activities. The present study was to observe whether quercetin could improve therapeutic index of DOX and explore its mechanisms. METHODS: Effects of quercetin on doxorubicin (DOX)-induced cytotoxicity were investigated in 4T1 cells and murine spleen cells by methylthiazoletetrazolium assay, flow cytometry and single cell gel electrophoresis. Influences of quercetin on therapeutic efficacy and systemic toxicity of DOX were evaluated in BALB/c mice with 4T1 breast cancer. Hypoxia-inducible factor-1 alpha (HIF-1alpha) in tumor and normal cells was examined to explore mechanisms of quercetin by Western blot and enzyme-linked immunosorbent assay. RESULTS: In vitro, quercetin at dose less than 100 muM had only slight effects on cell viability and DOX-induced cytotoxicity in 4T1 cells under normoxia, but it could reverse 4T1 cell resistance to DOX under hypoxia and protect spleen cells against DOX-induced cytotoxicity. In vivo, quercetin suppressed tumor growth and prolonged survival in BALB/c mice bearing 4T1 breast cancer. Importantly, quercetin enhanced therapeutic efficacy of DOX and simultaneously reduced DOX-induced toxic side effects. Further study showed that quercetin suppressed intratumoral HIF-1alpha in a hypoxia-dependent way but increased its accumulation in normal cells. HIF-1alpha siRNA abolished effects of quercetin on both tumor and normal cells. CONCLUSIONS: These results suggested that quercetin could improve therapeutic index of DOX by its opposing effects on HIF-1alpha in tumor and normal cells, and was a promising candidate as anticancer agents. Cancer Chemother Pharmacol. 2009 May 26. [Epub ahead of print] (Du G, et al 2009)

Sensitization of human Ewing’s tumor cells to chemotherapy and heat treatment by the bioflavonoid quercetin.
BACKGROUND: The bioflavonoid quercetin, a polyphenolic compound widely distributed in the plant kingdom, has been demonstrated to exert cytostatic activity against a variety of tumor cells in vitro and in vivo. It may be useful in cancer therapy as a thermosensitizer by increasing the cell killing effect of hyperthermia and chemotherapy because of its ability to suppress heat-shock protein expression. MATERIALS AND METHODS: We investigated the effect of quercetin combined with two cytotoxic agents, cDDP (cis-diamminedichloroplatinum II) and VP-16 (etoposide), under various heat-shock conditions in two Ewing’s tumor cell lines SK-ES-1 and RD-ES, using XTT-assay and Western blot analysis. RESULTS: Induction of thermotolerance by a sublethal heat-shock (42 degrees C, 1 hour) led to a transient resistance against subsequent heat treatment alone or combined thermochemotherapy with the crosslinking agent cDDP or the topoisomerase II inhibitor VP-16. Quercetin (> or = 50 microM) applied for 24 hours inhibited cell proliferation, increased the cytotoxic activity of cDDP or VP-16 alone or combined with simultaneous hyperthermia and suppressed the development of thermotolerance. Hyperthermia (43 degrees C, 45 degrees C for 1 hour) induced high expression of the inducible form of HSP70, whereas HSP27, which is constitutively expressed at normothermic conditions, is only slightly induced by 43 degrees C and nearly completely suppressed at 45 degrees C. Induction of thermotolerance is accompanied by an elevated expression of both HSP70 and HSP27. Quercetin (> or = 50 microM), alone as well as in combination with thermochemotherapy, inhibited the expression of both HSP70 and HSP27. CONCLUSION: These data suggest that the bioflavonoid quercetin potentially may be useful in clinical trials for optimizing the efficacy of hyperthermia in combination with chemotherapy. Anticancer Res. 2003 Jul-Aug;23(4):3359-66. (Debes A, et al 2003)

Inhibition of heat shock proteins (HSP) expression by quercetin and differential doxorubicin sensitization in neuroblastoma and Ewing’s sarcoma cell lines.Neuroblastoma (NB) and Ewing’s sarcoma (ES) represent the most common extracranial solid tumors of childhood. Heat shock proteins (HSP) are elevated in cancer cells and their over-expression was correlated to drug-resistance. In this work we identified the HSP by a sensitive proteomic analysis of NB and ES cell lines, then, we studied the HSP response to doxorubicin. Some identified HSP were constitutively more expressed in NB than in ES cells. Doxorubicin-stimulated HSP response only in NB cells. Quercetin was found to inhibit HSP expression depleting heat shock factor 1 (HSF1) cellular stores. Quercetin caused a higher anti-proliferative effect in NB (IC(50): 6.9 +/- 5.8 mumol/L) than in ES cells (IC(50): 85.5 +/- 53.1 mumol/L). Moreover, quercetin caused a very pronounced doxorubicin sensitizing effect in NB cells (241 fold IC(50) decrease) and a moderate effect in ES cells. HSP involvement in NB cells sensitization was confirmed by the silencing of HSF1. Quercetin treatment and HSF1 silencing increased the pro-apoptotic effect of doxorubicin. In conclusion, the higher HSP levels, observed in NB cells, did not confer increased resistance to doxorubicin; on the contrary, HSP inhibition by quercetin or gene silencing caused higher sensitization to doxorubicin. These results may have a potential application in the treatment of NB. J Neurochem. 2007 Nov;103(4):1344-54. Epub 2007 Aug 6. (Zanini C, et al 2007)

Resveratrol
Combined effects of resveratrol and paclitaxel on lung cancer cells.
Resveratrol (3,4′,5-trihydroxystilbene) is a phytoalexin found in grapes and other food products that can prevent cancer. We studied the in vitro biological activity of this compound by examining its effect on proliferation and inducing apoptosis in three lung cancer cell lines (A549, EBC-1, Lu65). Resveratrol inhibited the growth of A549, EBC-1 and Lu65 lung cancer cells by 50% (ED50) at concentrations between 5-10 microM. We also examined the combined effects in these cells of resveratrol and paclitaxel, an essential chemotherapeutic agent against lung cancer. Although simultaneous exposure to resveratrol plus paclitaxel did not result in significant synergy, resveratrol (10 microM, 3 days) significantly enhanced the subsequent antiproliferative effect of paclitaxel. In addition, resveratrol as well as paclitaxel induced apoptosis in EBC-1 and Lu65 cells, as measured by TUNEL and caspase assays, as well as flow cytometry. Resveratrol (10 microM, 3 days) similarly enhanced the subsequent apoptotic effects of paclitaxel. We examined the effects of resveratrol and paclitaxel on levels of p21waf1, p27kip1, E-cadherin, EGFR and Bcl-2 in EBC-1 cells. Resveratrol (10 microM, 3 days) prior to paclitaxel induced p21waf1 expression approximately 4-fold. These results suggest that resveratrol may be a promising alternative therapy for lung cancer and that lung cancer cells exposed to resveratrol have a lowered threshold for killing by paclitaxel. Anticancer Res. 2003 Sep-Oct;23(5A):4039-46. (Kubota T, et al 2003)

Clusterin mediates TRAIL resistance in prostate tumor cells.
One of the major obstacles in curing prostate cancer is the development of drug resistance to docetaxel, which is the gold standard for the treatment of this disease. It is not only imperative to discover the molecular basis of resistance but also to find therapeutic agents that can disrupt the resistant pathways. Based on initial findings that docetaxel-resistant PC3-DR and DU145-DR prostate tumor cell lines express tumor necrosis factor-related apoptosis inducing ligand (TRAIL) receptors, we examined whether TRAIL could be used as an alternative method to kill PC3-DR and DU145-DR cells. However, these tumor cells were found to be TRAIL resistant. Because PC3-DR and DU-145-DR cells were previously shown by us to be clusterin positive, we examined if clusterin could play a role in TRAIL resistance. We found that resveratrol could sensitize docetaxel-resistant tumor cells to TRAIL, and it worked by blocking clusterin expression. In particular, small interfering RNA clusterin expression in the cell lines was sufficient to produce apoptosis by TRAIL. Further analysis indicated that resveratrol functions as an effective tyrosine kinase inhibitor, similar to its analogue, piceatannol, and could inhibit Src and Jak kinases, thus resulting in loss of Stat1 activation. We have shown earlier that Stat1 is essential for gene transcription of clusterin. These results, taken together, show that resveratrol could be a useful new therapeutic agent to combat docetaxel resistance. Mol Cancer Ther. 2007 Nov;6(11):2938-47. (Sallman DA, et al 2007)

Resveratrol is a naturally occurring anticancer compound present in grapes and wine that undergoes pronounced metabolism in human intestine and liver. In order to determine whether resveratrol is also bio-transformed in human breast carcinoma, metabolism experiments were conducted in breast tumor and adjacent non-tumorous specimens from 13 patients. Resveratrol was metabolized in cytosolic tissue fractions to resveratrol-3-O-sulfate: the formation rates were up to 33.5-fold higher in cancer samples than in peritumoral tissue. Further quantitative real-time RT-PCR analysis revealed similar expression of sulfotransferases SULT1A2, 1A3, and 1E1 in the paired control and tumor tissues. Sulfotransferase SULT1A1 expression was below the detection limit in all samples. Interestingly, mRNA expression of steroid sulfatase STS, but not of arylsulfatases ARS-A and ARS-B, was significantly higher (p<0.0017) in non-malignant specimens than in tumor tissue samples, which might explain the higher resveratrol-3-O-sulfate concentrations in breast cancer specimens. Cellular localization of SULT1A3 and STS was also assessed by indirect immunofluorescence on paraffin-embedded sections from control and malignant breast tissue clearly showing a correlation of qRT-PCR data with protein expression of these two enzymes. Our data elucidate the metabolism of resveratrol in malignant and non-malignant breast tissue, which must be considered in humans after oral uptake of dietary resveratrol as a chemopreventive agent. Cancer Lett. 2009 Sep 9. [Epub ahead of print] (Miksits M, et al 2009)

Resveratrol and Genistein
Chemoprotective action of resveratrol and genistein from apoptosis induced in human peripheral blood lymphocytes.Extensive research is being carried out to analyse the importance of plant products such as resveratrol and genistein, which are known to exert a variety of pharmacological effects. This study aims at evaluating the protective role of these compounds against the apoptosis induced in normal cells by cytotoxic anticancer agents such as cisplatin and mytomycin C during therapy. Despite the broad antineoplastic action of cisplatin and mitomycin C, their genotoxicity in normal cell might lead to the induction of secondary malignancies. Therefore, the problem of identifying plant compounds, which might exert protective action in normal cells, gains lot of significance. We have analyzed the chemoprotective effect of plant compounds on peripheral blood human lymphocytes when exposed to cisplatin and mitomycin C by pre-treating and post-treating them with resveratrol and genistein at 100 microM concentration Biochemical alterations occurring in many cells during apoptosis include loss of plasma membrane phospholipid asymmetry, DNA fragmentation, and activation of caspase-3, et cetera, and have been assessed. Fluorescence microscopy, flow cytometric techniques have clearly demonstrated that resveratrol and genistein are efficient in protecting lymphocytes undergoing DNA damage when exposed to cisplatin and mitomycin C and exerted their activity by reducing the caspase 3 expression. An interesting observation is that, these compounds offered their protective effect by reducing their apoptotic potential on membrane and nucleic acids against cytotoxic agents, cisplatin, and mitomycin C. These results suggest that resveratrol and genistein might be useful for risk assessments in advance of clinical trials and could be considered as a strong candidate in pharmacogenomics or nutriprotective arena. J Biomol Struct Dyn. 2008 Feb;25(4):425-34. (Subbiah URaghunathan M. 2008)

Selenium disrupts estrogen receptor (alpha) signaling and potentiates tamoxifen antagonism in endometrial cancer cells and tamoxifen-resistant breast cancer cells.
Tamoxifen, a selective estrogen receptor (ER) modulator, is the most widely prescribed hormonal therapy treatment for breast cancer. Despite the benefits of tamoxifen therapy, almost all tamoxifen-responsive breast cancer patients develop resistance to therapy. In addition, tamoxifen displays estrogen-like effects in the endometrium increasing the incidence of endometrial cancer. New therapeutic strategies are needed to circumvent tamoxifen resistance in breast cancer as well as tamoxifen toxicity in endometrium. Organic selenium compounds are highly effective chemopreventive agents with well-documented benefits in reducing total cancer incidence and mortality rates for a number of cancers. The present study shows that the organic selenium compound methylseleninic acid (MSA, 2.5 micromol/L) can potentiate growth inhibition of 4-hydroxytamoxifen (10(-7) mol/L) in tamoxifen-sensitive MCF-7 and T47D breast cancer cell lines. Remarkably, in tamoxifen-resistant MCF-7-LCC2 and MCF7-H2Delta16 breast cancer cell lines and endometrial-derived HEC1A and Ishikawa cells, coincubation of 4-hydroxytamoxifen with MSA resulted in a marked growth inhibition that was substantially greater than MSA alone. Growth inhibition by MSA and MSA + 4-hydroxytamoxifen in all cell lines was preceded by a specific decrease in ER(alpha) mRNA and protein without an effect on ER(beta) levels. Estradiol and 4-hydroxytamoxifen induction of endogenous ER-dependent gene expression (pS2 and c-myc) as well as ER-dependent reporter gene expression (ERE(2)e1b-luciferase) was also attenuated by MSA in all cell lines before effect on growth inhibition. Taken together, these data strongly suggest that specific decrease in ER(alpha) levels by MSA is required for both MSA potentiation of the growth inhibitory effects of 4-hydroxytamoxifen and resensitization of tamoxifen-resistant cell lines.Mol Cancer Ther. 2005 Aug;4(8):1239-49. (Shah YM, et al 2005)

Combination of methylselenocysteine with tamoxifen inhibits MCF-7 breast cancer xenografts in nude mice through elevated apoptosis and reduced angiogenesis.
To investigate the therapeutic effect of methylselenocysteine (MSC) combined with tamoxifen in MCF-7 breast cancer xenograft and the underlying mechanisms. MCF-7 breast cancer xenograft was established in ovariectomized female athymic nude mice and treated with tamoxifen and/or MSC. Tumor size was measured twice a week. Immunohistochemistry and TUNEL assays were used to measure ERalpha expression, ERalpha target genes (progesterone receptor (PR) and cyclin D1 expression), Ki-67 index, apoptosis and microvessel density. Combined treatment with tamoxifen and MSC synergistically inhibited tumor growth compared to MSC alone and tamoxifen alone. MSC alone or MSC + tamoxifen significantly reduced ERalpha, PR and cyclin D1, Ki67 index and microvessel density while increasing apoptosis in tumor tissues. These findings demonstrate synergistic growth inhibition of ERalpha positive breast cancer xenografts by combination of tamoxifen with organic selenium compounds. Organic selenium may provide added benefit when combined with tamoxifen in adjuvant therapy or prevention. Breast Cancer Res Treat. 2008 Oct 15. [Epub ahead of print] (Li Z, et al 2008)
Methylseleninic acid synergizes with tamoxifen to induce caspase-mediated apoptosis in breast cancer cells.
Tamoxifen has efficacy as a breast cancer therapy and chemoprevention agent. However, toxicity and resistance to tamoxifen limit its clinical application. There is an urgent need to develop compounds that may be combined with tamoxifen to improve efficacy and overcome toxicity and resistance. We showed previously that the organoselenium compound methylseleninic acid (MSA) increased the growth-inhibitory effect of tamoxifen and reversed tamoxifen resistance in breast cancer cells. In this study, we examined the mechanism for induction of apoptosis by MSA combined with tamoxifen in tamoxifen-sensitive and tamoxifen-resistant breast cancer cells. 4-hydroxytamoxifen (TAM; 10(-7) mol/L) alone resulted in cell cycle arrest but no apoptosis, whereas MSA alone (10 micromol/L) induced apoptosis in tamoxifen-sensitive cells. Combination of MSA with TAM resulted in a synergistic apoptosis in both tamoxifen-sensitive and tamoxifen-resistant breast cancer cells compared with either agent alone. MSA and MSA combined with TAM induced apoptosis through the intrinsic, mitochondrial apoptotic pathway. MSA induced a sequential activation of caspase-9 and then caspase-8. These results indicate that the growth inhibition synergy and reversal of tamoxifen resistance by combination of selenium with tamoxifen occurs via a tamoxifen-induced cell cycle arrest, allowing more cells to enter the intrinsic apoptotic pathway elicited by selenium. Mol Cancer Ther. 2008 Sep;7(9):3056-63. (Li ZCarrier LRowan BG.2008)

Silibinin (an active constituent of Milk Thistle extract)
Silibinin sensitizes human prostate carcinoma DU145 cells to cisplatin- and carboplatin-induced growth inhibition and apoptotic death.
In several recent studies, we have shown that silibinin inhibits the growth of human prostate cancer cells (PCA) both in vitro and in vivo. Here, we investigated the effect of silibinin in combination with cisplatin and carboplatin on human PCA DU145 cell growth and apoptosis. Cisplatin alone at 2 microg/ml dose produced 48% cell growth inhibition, whereas a combination with 50-100 microM silibinin resulted in 63-80% (p<0.05-0.001) growth inhibition. Similarly, compared to 68% growth inhibition at 20 microg/ml carboplatin, addition of 50-100 microM doses of silibinin caused 80-90% inhibition (p<0.005-0.001). In the studies assessing the effect of these combinations on cell cycle progression, a combination of cisplatin or carboplatin with silibinin resulted in a stronger G2-M arrest, compared to these agents alone showing a moderate G2-M and G1 arrests in case of cisplatin and silibinin, and a complete S phase arrest with carboplatin, respectively. A stronger G2-M arrest by these combinations was accompanied by a substantial decrease in the levels of cdc2, cyclin B1 and cdc25C. Silibinin/platinum compound combinations were also effective in inducing apoptosis where cisplatin and carboplatin when combined with silibinin enhanced apoptosis from 8 to 15% and from 20 to 40%, respectively. Apoptosis induction was further confirmed by PARP and caspases 3, 9 and 7 whose cleaved levels were also enhanced by combination treatment. In addition, there was a significant increase in cytochrome c release in the cytosol following treatment of DU145 cells with these combinations. Together, these results show a substantial increase in the efficacy of platinum compounds on human PCA cells, when combined with silibinin, which provide a rationale for further investigations with these combinations. Int J Cancer. 2003 Sep 20;106(5):699-705. (Dhanalakshmi S, et al 2003)

Synergistic anti-cancer effects of silibinin with conventional cytotoxic agents doxorubicin, cisplatin and carboplatin against human breast carcinoma MCF-7 and MDA-MB468 cells.
Significant emphasis is being placed on combination chemotherapy of cancer using cytotoxic agents and naturally occurring chemopreventive agents, having different mechanisms of action with non-overlapping toxicity. In this regard, here we assessed whether a cancer preventive agent silibinin synergizes the therapeutic potential of doxorubicin (Dox), cisplatin or carboplatin, the chemotherapeutic drugs, in both estrogen-dependent and -independent human breast carcinoma, MCF-7 and MDA-MB468 cells, respectively. When tested alone, each of the four agents showed growth inhibition in both the cell lines in a dose- and a time-dependent manner. Based on their growth inhibitory effects, several combinations of silibinin (25-100 microM) with Dox (10-75 nM), cisplatin (0.2-2 microg/ml) or carboplatin (2-20 microg/ml) were next assessed for their synergistic, additive and/or antagonistic efficacy towards cell growth inhibition and apoptotic death. The strongest synergistic effects for cell growth inhibition [combination index (CI) 0.35 for MCF-7 and 0.45 for MDA-MB468 cells] were evident at a silibinin dose of 100 microM plus 25 nM Dox, in both the cell lines. Most of the CIs for other combinations of these three drugs with silibinin also suggested strong synergistic effects for cell growth inhibition in both MCF-7 and MDA-MB468 cells. In quantitative apoptosis studies, combination of silibinin with Dox resulted in much stronger apoptotic death compared to each agent alone in both cell lines. In case of silibinin combination with cisplatin, it showed no additional apoptotic effect in either cell line. Similarly, silibinin plus carboplatin combination showed stronger apoptotic effect only in MCF-7 cells. Together, these results suggest a possible synergism between silibinin and conventional cytotoxic agents for breast cancer treatment, and warrant further in vivo studies in pre-clinical breast cancer models. Oncol Rep. 2004 Feb;11(2):493-9. (Tyagi AK, et al 2004)

Soy
Tamoxifen, soy, and lifestyle factors in Asian American women with breast cancer.
PURPOSE: Soy foods have been a staple in Asia for centuries but the consumption of this food in the West is recent. Intake of soy among women at high risk for or with breast cancer has become a public health concern because genistein, a major component of soy, has weak estrogenic effects on breast epithelium, and has been found to negate the benefit of tamoxifen in some animal and in vitro studies. PATIENTS AND METHODS: We conducted a cross-sectional study in Asian Americans with breast cancer who were tamoxifen users (n = 380) to investigate the association between soy intake and circulating levels of tamoxifen and its metabolites (N-desmethyl tamoxifen [N-DMT], 4-hydroxytamoxifen [4-OHT], and 4-hydroxy-N-desmethyl-tamoxifen [endoxifen]). RESULTS: Serum levels of tamoxifen or its metabolites were unrelated to self-reported intake of soy or serum levels of isoflavones. Blood levels of tamoxifen were 81% higher in postmenopausal women age 65 or older compared with premenopausal women age 45 or younger (P = .005); similar patterns of results were observed for the tamoxifen metabolites. Levels of N-DMT were 27% (P = .03) lower among women in the highest tertile of body mass index (BMI, > 24.4 kg/m2) compared with those in the lowest category (BMI 21.5). Women who used hypertensive medications had higher levels of tamoxifen (P = .02) and N-DMT (P = .04) compared with nonusers. CONCLUSION: We found no evidence that soy intake adversely affected levels of tamoxifen or its metabolites. However, age, menopausal status, BMI, and use of hypertensive medications significantly influenced circulating levels of tamoxifen and its metabolites in this population. J Clin Oncol. 2007 Jul 20;25(21):3024-30. Epub 2007 May 29. (Wu AH, et al 2007)

Uncaria tomentosa bark (Pentacyclic oxindole alkaloid mitraphylline)
Cytotoxic Effect of the Pentacyclic Oxindole Alkaloid Mitraphylline Isolated from Uncaria tomentosa Bark on Human Ewing’s Sarcoma and Breast Cancer Cell Lines.Preparations from UNCARIA TOMENTOSA, a South American Rubiaceae, have been used in the Peruvian traditional medicine for the treatment of infective, inflammatory and tumoral processes. In this study, the pentacyclic oxindole alkaloid mitraphylline was isolated from the dried inner bark of this plant species, and its structure elucidated by analysis of NMR spectroscopic data. Mitraphylline was differentially identified from its stereoisomeric pair isomitraphylline by (15)N-NMR. Its antiproliferative and cytotoxic effects have been tested on human Ewing’s sarcoma MHH-ES-1 and breast cancer MT-3 cell lines, using cyclophosphamide and vincristine as reference controls. A Coulter counter was used to determine viable cell numbers, followed by the application of the tetrazolium compound MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy phenyl)-2-(4-sulfophenyl)-2H-tetrazolium] an inner salt. A colorimetric method was employed to evaluate cell viability in this cytotoxic assay. Micromolar concentrations of mitraphylline (5 microM to 40 microM) inhibited the growth of both cell lines in a dose-dependent manner. The IC (50) +/- SE values were 17.15 +/- 0.82 microM for MHH-ES-1 and 11.80 +/- 1.03 microM for MT-3 for 30 hours, smaller than those obtained for the reference compounds. This action suggests that the pentacyclic oxindole alkaloid mitraphylline might be a new promising agent in the treatment of both human sarcoma and breast cancer. Planta Med. 2009 Sep 1. [Epub ahead of print] (García Giménez D, et al 2009)

Vitamin E
Preventing paclitaxel-induced peripheral neuropathy: a phase II trial of vitamin E supplementation.
A randomized, controlled trial was performed to assess the efficacy and safety of vitamin E supplementation for prophylaxis against paclitaxel-induced peripheral neuropathy (PIPN). Thirty-two patients undergoing six courses of paclitaxel-based chemotherapy were randomly assigned to receive either chemotherapy with vitamin E (300 mg twice a day, Group I) or chemotherapy without vitamin E supplementation (Group II). A detailed neurological examination and electrophysiological study was performed during and 3 months after chemotherapy. The severity of PIPN was summarized by means of a modified Peripheral Neuropathy (PNP) score. The incidence of neurotoxicity differed significantly between groups, occurring in 3/16 (18.7%) patients assigned to the vitamin E supplementation group and in 10/16 (62.5%) controls (P=0.03). The relative risk (RR) of developing PIPN was significantly higher in controls than in vitamin E group patients (RR=0.3, 95% confidence interval (CI)=0.1-0.9). Mean PNP scores were 2.25+/-5.1 (range 0-15) for patients in Group I and 11+/-11.63 (range 0-32) for those in Group II (P=0.01). Vitamin E supplementation was well tolerated and showed an excellent safety profile. This study shows that vitamin E effectively and safely protects patients with cancer from the occurrence of paclitaxel-induced peripheral nerve damage. A double-blind, placebo-controlled trial is needed to confirm these results. J Pain Symptom Manage. 2006 Sep;32(3):237-44. (Argyriou AA, et al 2006)

A randomized controlled trial evaluating the efficacy and safety of vitamin E supplementation for protection against cisplatin-induced peripheral neuropathy: final results.
AIM: A randomized, open label with blind assessment, controlled trial was performed to assess efficacy and adverse-event profile of vitamin E, given as supplementation for prophylaxis against cisplatin-induced peripheral neuropathy (CIPN). PATIENTS AND METHODS: A total of 30 patients scheduled to receive six courses of cumulative cisplatin-based regimens were randomly allocated to treatment and control groups and were then studied by means of neurological examination and electrophysiological study. Patients assigned to group I (n=14) orally received vitamin E at a daily dose of 600 mg/day during chemotherapy and 3 months after its cessation were compared to patients of group II (n=16), who received no vitamin E supplementation and served as controls. The severity of neurotoxicity was summarized by means of a modified Peripheral Neuropathy (PNP) score. RESULTS: The incidence of neurotoxicity differed significantly between groups, occurring in 3/14 (21.4%) of patients assigned to the vitamin E supplementation group and in 11/16 (68.5%) of controls (p=0.026). The relative risk (RR) of developing neurotoxicity was significantly higher in case of controls, RR=2.51, 95% C.I.=1.16-5.47. Mean PNP scores were 4.99+/-1.33 for patients of group I and 10.47+/-10.62 for controls, (p=0.023). None of the adverse events or deaths occurred, were judged as likely to be related to the vitamin E supplementation. CONCLUSION: Vitamin E effectively and safely protects patients with cancer from occurrence of cisplatin neurotoxicity. Support Care Cancer. 2006 Nov;14(11):1134-40. Epub 2006 Apr 19. (Argyriou AA, et al 2006)

Withania somnifera
Enhancement of antitumor effect of paclitaxel in combination with immunomodulatory Withania somnifera on benzo(a)pyrene induced experimental lung cancer.The current experimental work deals with the immunomodulatory studies on the extract of Withania somnifera (L.) Dunal root powder against benzo(a)pyrene induced lung cancer in male Swiss albino mice. In our previous study, we reported the antioxidant and anticarcinogenic effect of W. somnifera (L.) Dunal along with paclitaxel. Immune dysfunction has been found to be associated with cancer and chemotherapy. Benzo(a)pyrene induced cancer animals were treated with 400mg/kg bodyweight of W. somnifera (L.) Dunal extract for 30 days significantly alters the levels of immuno-competent cells, immune complexes and immunoglobulins. Based on the data, the carcinogen as well as the paclitaxel affects the immune system, the toxic side effects on the immune system is more reversible and more controllable by W. somnifera (L.) Dunal. These results concluded the immunomodulatory activity of W. somnifera (L.) Dunal extract, which is a known immunomodulator in indigenous medicine. Chem Biol Interact. 2006 Feb 25;159(3):180-5. Epub 2005 Dec 22. (Senthilnathan P, et al 2006)

The protective effect of a purified extract of Withania somnifera against doxorubicin-induced cardiac toxicity in rats.
The therapeutic value of doxorubicin as an effective antineoplastic agent is limited by its cardiotoxic side-effects. The administration of doxorubicin (10 mg/kg) to male Wistar rats induced necrosis and apoptosis in heart tissues. It also caused oxidative stress damage as evidenced by the elevation of malondialdehyde and protein carbonyl levels and catalase activity, accompanied by the concurrent depletion of total antioxidant capacity and of superoxide dismutase level in cardiac tissues. The doxorubicin-induced cardiotoxicity and oxidative stress damage were also accompanied by increases of myeloperoxidase activity, total calcium content, and the expression of Bcl-2 protein in heart tissues. Most of these doxorubicin-induced biochemical and histological alterations were effectively attenuated by prior administration of purified standardized extract (1.5% withanolides; manufactured by Idea Sphere Inc., American Fork, UT, USA) of Withania somnifera (300 mg/kg).Thus, Withania may play a role in the protection against cardiotoxicity and thus might be a useful adjuvant therapy where doxorubicin is the cancer-treating drug. Cell Biol Toxicol. 2008 Jan;24(1):63-73. Epub 2007 May 23(Hamza AAmin ADaoud S.2008)

Anticancer effects of phytosterols.
Phytosterol and stanol (or phytosterols) consumption reduces intestinal cholesterol absorption, leading to decreased blood LDL-cholesterol levels and lowered cardiovascular disease risk. However, other biological roles for plant sterols and stanols have also been proposed. The objective of this review is to critically examine results from recent research regarding the potential effects and mechanisms of action of phytosterols on forms of cancer. Considerable emerging evidence supports the inhibitory actions of phytosterols on lung, stomach, as well as ovarian and breast cancer. Phytosterols seem to act through multiple mechanisms of action, including inhibition of carcinogen production, cancer-cell growth, angiogenesis, invasion and metastasis, and through the promotion of apoptosis of cancerous cells. Phytosterol consumption may also increase the activity of antioxidant enzymes and thereby reduce oxidative stress. In addition to altering cell-membrane structure and function, phytosterols probably promote apoptosis by lowering blood cholesterol levels. Moreover, consumption of phytosterols by healthy humans at the recommended level of 2 g per day does not cause any major health risks. In summary, mounting evidence supports a role for phytosterols in protecting against cancer development. Hence, phytosterols could be incorporated in diet not only to lower the cardiovascular disease risk, but also to potentially prevent cancer development. Eur J Clin Nutr. 2009 Jul;63(7):813-20. Epub 2009 Jun 3. (Woyengo TA,Ramprasath VRJones PJ. 2009)

Lycopene in the prevention of prostate cancer.
Based on the evidence from epidemiologic, animal, and in vitro data and human clinical trials, it is evident that lycopene, a non-provitamin A carotenoid, is a promising agent for prostate cancer chemoprevention. It is also clear that the form of lycopene used (purified versus food sources), dose of lycopene and concomitant use with other carotenoids and antioxidants, duration of exposure, specific target populations, and stage of disease appear to play a major role in determining agonistic or antagonistic effects. Based on our review, there is enough evidence to warrant use of lycopene in phase I and II clinical trials to examine its safety and efficacy as a potential chemopreventive agent for prostate cancer. The objective of this article is to review this evidence from epidemiologic, animal, in vitro, and clinical trials and provide the need and rationale to examine further the role of lycopene for prostate cancer prevention. J Soc Integr Oncol. 2008 Winter;6(1):29-36.(Dahan KFennal MKumar NB.2008)

Isoflavones are safe compounds for therapeutical applications – Evaluation of in vitro data.
Isoflavone-rich food and food supplements have gained increasing popularity also in the Western world. Their weak estrogenic effect has been considered as a potential risk, although all epidemiological studies and clinical trials show a significant cancer protection and decreased risk of cardiovascular diseases. In vitro data suggest that the concerted action of the isoflavones and their metabolites show antiproliferative behaviour, reduce angiogenesis, reduce tumor progression and exert antiinflammatory effects. For the evaluation of the biological effects, special emphasis has to be put on the concerted action between the isoflavones and their metabolites. For instance, while isolated genistein shows some growth promoting effect at low concentrations, the metabolite equol or soy extract show growth retardation as well as higher concentrations of genistein do. The isoflavones have multiple affinities to other members of the steroid hormone receptor superfamily. The beneficial effect on metabolic diseases and weight reduction by isoflavone consumption can be partly explained by its affinity for the PPAR family. In light of the in vitro experiments, together with the epidemiological observations and the clinical experience, isoflavones can be considered as safe compounds and their consumption as food and food supplements has to be promoted. Gynecol Endocrinol. 2009 Jul 7:1-27. [Epub ahead of print] (Reiter EBeck VMedjakovic SJungbauer A.2009)

Multiple molecular targets of resveratrol: Anti-carcinogenic mechanisms.
Plant-derived polyphenolic compounds, such as the stilbene resveratrol (trans-3,4′,5-trihydroxystilbene), have been identified as potent anti-cancer agents. Extensive in vitro studies revealed multiple intracellular targets of resveratrol, which affect cell growth, inflammation, apoptosis, angiogenesis, and invasion and metastasis. These include tumor suppressors p53 and Rb; cell cycle regulators, cyclins, CDKs, p21WAF1, p27KIP and INK and the checkpoint kinases ATM/ATR; transcription factors NF-kappaB, AP-1, c-Jun, and c-Fos; angiogenic and metastatic factors, VEGF and matrix metalloprotease 2/9; cyclooxygenases for inflammation; and apoptotic and survival regulators, Bax, Bak, PUMA, Noxa, TRAIL, APAF, survivin, Akt, Bcl2 and Bcl-X(L). In addition to its well-documented anti-oxidant properties, there is increasing evidence that resveratrol exhibits pro-oxidant activity under certain experimental conditions, causing oxidative DNA damage that may lead to cell cycle arrest or apoptosis. This review summarizes in vitro mechanistic data available for resveratrol and discusses new potential anti-cancer targets and the antiproliferative mechanisms of resveratrol. Arch Biochem Biophys. 2009 Jun 15;486(2):95-102. (Athar M, et al 2009)

Viscum album L. extracts in breast and gynaecological cancers: a systematic review of clinical and preclinical research.
BACKGROUND: Viscum album L. extracts (VAE, European mistletoe) are a widely used medicinal plant extract in gynaecological and breast-cancer treatment. METHODS: Systematic review to evaluate clinical studies and preclinical research on the therapeutic effectiveness and biological effects of VAE on gynaecological and breast cancer. Search of databases, reference lists and expert consultations. Criteria-based assessment of methodological study quality. RESULTS: 19 randomized (RCT), 16 non-randomized (non-RCT) controlled studies, and 11 single-arm cohort studies were identified that investigated VAE treatment of breast or gynaecological cancer. They included 2420, 6399 and 1130 patients respectively. 8 RCTs and 8 non-RCTs were embedded in the same large epidemiological cohort study. 9 RCTs and 13 non-RCTs assessed survival; 12 reported a statistically significant benefit, the others either a trend or no difference. 3 RCTs and 6 non-RCTs assessed tumour behaviour (remission or time to relapse); 3 reported statistically significant benefit, the others either a trend, no difference or mixed results. Quality of life (QoL) and tolerability of chemotherapy, radiotherapy or surgery was assessed in 15 RCTs and 9 non-RCTs. 21 reported a statistically significant positive result, the others either a trend, no difference, or mixed results. Methodological quality of the studies differed substantially; some had major limitations, especially RCTs on survival and tumour behaviour had very small sample sizes. Some recent studies, however, especially on QoL were reasonably well conducted. Single-arm cohort studies investigated tumour behaviour, QoL, pharmacokinetics and safety of VAE. Tumour remission was observed after high dosage and local application. VAE application was well tolerated. 34 animal experiments investigated VAE and isolated or recombinant compounds in various breast and gynaecological cancer models in mice and rats. VAE showed increase of survival and tumour remission especially in mice, while application in rats as well as application of VAE compounds had mixed results. In vitro VAE and its compounds have strong cytotoxic effects on cancer cells. CONCLUSION: VAE shows some positive effects in breast and gynaecological cancer. More research into clinical efficacy is warranted. J Exp Clin Cancer Res. 2009 Jun 11;28:79.  (Kienle GSGlockmann ASchink MKiene H. 2009)

A systematic review of the effectiveness of Chinese herbal medication in symptom management and improvement of quality of life in adult cancer patients.
The aim of this systematic review was to assess the effectiveness of Chinese medicinal herbs used concurrently with cancer treatments in terms primarily of toxicity management but also quality of life and survival in adult cancer patients. Forty-nine trials met the inclusion criteria and were reviewed according to standard processes of systematic reviews. These trials included 3992 patients. All studies with the exception of one were of low methodological quality. The vast majority of the studies have shown that Chinese medicinal herbs improved treatment side effects, quality of life, and performance status, and some have provided evidence of tumour regression and increased survival. While no clinical recommendations can derive from such low quality studies, the number of studies reporting positive results is high enough to suggest that Chinese medicinal herbs may have a role in cancer care. However, more methodologically rigorous studies need to be developed as a priority before any firm conclusions can be drawn. Complement Ther Med. 2009 Apr;17(2):92-120. Epub 2008 Dec 25. (Molassiotis APotrata BCheng KK. 2009)

Synergistic anti-cancer effect of baicalein and silymarin on human hepatoma HepG2 Cells.
This study investigated the effect of baicalein, silymarin, and their combination, on two human liver-derived cell lines, HepG2 (hepatocellular carcinoma) and Chang liver (non-tumor liver cells). It was found that 6.75 microg/ml baicalein or 100 microg/ml silymarin alone significantly inhibited the growth of HepG2. When baicalein was used in combination with silymarin on HepG2, an additive effect at 24 h and a synergistic effect at 48 h were observed. The viability at 48 h was 85.62% from 6.75 microg/ml baicalein treatment; but the viability reduced to 49.67%, 38.56%, and 19.61% when 25, 50, and 100 microg/ml silymarin respectively, was added to the treatment. By contrast, each treatment had little or no effect on Chang liver. Compared to treatment of baicalein or silymarin alone on HepG2, combination of both drugs synergistically increased the percentages of cells in G0/G1 phase and decreased those in S-phase, which were associated with up-regulation of Rb, p53, p21(Cip1) and p27(Kip1) and down-regulation of cyclin D1, cyclin E, CDK4 and phospho-Rb. The results indicate that the combination of baicalein and silymarin eradicates tumor cells efficiently, has minimal deleterious effects to the surrounding normal cells, and offers mechanistic insight for further exploitation of HCC treatment. Food Chem Toxicol. 2009 Mar;47(3):638-44. Epub 2008 Dec 25. (Chen CH, et al 2009)

Curcumin disrupts the Mammalian target of rapamycin-raptor complex.Curcumin (diferuloylmethane), a polyphenol natural product of the plant Curcuma longa, is undergoing early clinical trials as a novel anticancer agent. However, the anticancer mechanism of curcumin remains to be elucidated. Recently, we have shown that curcumin inhibits phosphorylation of p70 S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E (eIF4E) binding protein 1 (4E-BP1), two downstream effector molecules of the mammalian target of rapamycin complex 1 (mTORC1) in numerous cancer cell lines. This study was designed to elucidate the underlying mechanism. We observed that curcumin inhibited mTORC1 signaling not by inhibition of the upstream kinases, such as insulin-like growth factor 1 receptor (IGF-IR) and phosphoinositide-dependent kinase 1 (PDK1). Further, we found that curcumin inhibited mTORC1 signaling independently of protein phosphatase 2A (PP2A) or AMP-activated protein kinase AMPK-tuberous sclerosis complex (TSC). This is evidenced by the findings that curcumin was able to inhibit phosphorylation of S6K1 and 4E-BP1 in the cells pretreated with PP2A inhibitor (okadaic acid) or AMPK inhibitor (compound C), or in the cells expressing dominant-negative (dn) PP2A, shRNA to PP2A-A subunit, or dn-AMPKalpha. Curcumin did not alter the TSC1/2 interaction. Knockout of TSC2 did not affect curcumin inhibition of mTOR signaling. Finally, we identified that curcumin was able to dissociate raptor from mTOR, leading to inhibition of mTORC1 activity. Therefore, our data indicate that curcumin may represent a new class of mTOR inhibitor. Cancer Res. 2009 Feb 1;69(3):1000-8. Epub 2009 Jan 27. (Beevers CS, et al 2009)

Multiple molecular targets in cancer chemoprevention by curcumin.Carcinogenesis encompasses 3 closely associated stages: initiation, progression, and promotion. Phytochemicals are nonnutritive components of plants that are currently being studied in chemoprevention of various diseases for their pleiotropic effects and nontoxicity. Cancer chemoprevention involves the use of either natural or synthetic chemicals to prevent the initiation, promotion, or progression of cancer. Curcumin is the active constituent of turmeric, which is widely used as a spice in Indian cooking. It has been shown to possess anti-inflammatory, antioxidant, and antitumor properties. Curcumin has also been shown to be beneficial in all 3 stages of carcinogenesis. Much of its beneficial effect is found to be due to its inhibition of the transcription factor nuclear factor kappa B (NF-kappaB) and subsequent inhibition of proinflammatory pathways. This review summarizes the inhibition of NF-kappaB by curcumin and describes the recently identified molecular targets of curcumin. It is hoped that continued research will lead to development of curcumin as an anticancer agent. AAPS J. 2006 Jul 7;8(3):E443-9. (Thangapazham RLSharma AMaheshwari RK. 2006) (There are two very nice schematic representations of the mechanisms of curcumin’s actions in the free full text article above.)

Regulation of colorectal cancer cell apoptosis by the n-3 polyunsaturated fatty acids Docosahexaenoic and Eicosapentaenoic.
Several studies have suggested that the n-3 fatty acids Docosahexaenoic (DHA) and Eicosapentaenoic (EPA) have an important protective effect on colorectal cancer, and this could be at least partly due to their proapoptotic activity. It is unclear, however, how this phenomenon is triggered and what mechanisms are implicated. Here, we show that both DHA and EPA have an important proapoptotic effect on colorectal cancer cells with different molecular phenotypes but not in noncancerous cells. Apoptosis is caspase dependent, and both intrinsic and extrinsic pathways are implicated. The dimerization of Bax and Bak, the depolarization of the mitochondrial membrane, and the subsequent release of cytochrome c and Smac/Diablo to the cytosol evidence the activation of the intrinsic pathway. The implication of the extrinsic pathway is shown by the activation of caspase-8, along with the down-regulation of FLIP. The timing of caspase-8 activation, and the oligomerization of Bid with Bax, suggest a cross-talk with the intrinsic pathway. None of the death receptors that commonly initiate the extrinsic pathway: FAS, TNF-R1, and TRAIL-R2 are found to be responsible for triggering the apoptosis cascade induced by DHA and EPA. Neither PPARgamma nor cyclooxygenase-2, two likely candidates to regulate this process, play a significant role. Our findings suggest that the down-regulation of two key regulatory elements of the extrinsic and intrinsic pathways, FLIP and XIAP, respectively, is determinant in the induction of apoptosis by DHA and EPA. These fatty acids could potentially be useful adjuvant anticancer agents in combination with other chemotherapeutic elements. Cancer Prev Res (Phila Pa). 2009 Aug;2(8):732-42. Epub 2009 Jul 28. (Giros A, et al 2009)

Withaferin A Targets Heat Shock Protein 90 in Pancreatic Cancer Cells.
The purpose of this study is to investigate the efficacy and the mechanism of Hsp90 inhibition of Withaferin A (WA), a steroidal lactone occurring in Withania somnifera, in pancreatic cancer in vitro and in vivo. Withaferin A exhibited potent antiproliferative activity against pancreatic cancer cells in vitro (with IC(50)s of 1.24, 2.93 and 2.78muM) in pancreatic cancer cell lines Panc-1, MiaPaca2 and BxPc3, respectively. Annexin V staining showed that WA induced significant apoptosis in Panc-1 cells in a dose dependent manner. Western blotting demonstrated that WA inhibited Hsp90 chaperone activity to induce degradation of Hsp90 client proteins (Akt, Cdk4 and glucocorticoid receptor), which was reversed by the proteasomal inhibitor, MG132. WA-Biotin pull-down assay of Hsp90 using Panc-1 cancer cell lysates and purified Hsp90 showed that WA-biotin binds to C-terminus of Hsp90, which was competitively blocked by unlabeled WA. Co-immunoprecipitation exhibited that WA (10muM) disrupted Hsp90-Cdc37 complexes from 1-24 hour post treatment, while it neither blocked ATP binding to Hsp90, nor changed Hsp90-P23 association. WA (3, 6mg/kg) inhibited tumor growth in pancreatic Panc-1 xenografts by 30% and 58%, respectively. These data demonstrate that Withaferin A binds Hsp90, inhibits Hsp90 chaperone activity through an ATP independent mechanism, results in Hsp90 client protein degradation, and exhibits in vivo anticancer activity against pancreatic cancer. Biochem Pharmacol.2009 Sep 18. [Epub ahead of print] (Yu Y, et al 2009)

(-)-Epigallocatechin-3-gallate inhibits Hsp90 function by impairing Hsp90 association with cochaperones in pancreatic cancer cell line Mia Paca-2.(-)-Epigallocatechin-3-gallate [(-)-EGCG], the most abundant polyphenolic catechin in green tea, showed chemoprevention and anticancer activities. (-)-EGCG was reported to bind to the C-terminal domain of heat shock protein 90 (Hsp90). The purpose of this study is to investigate (-)-EGCG as a novel Hsp90 inhibitor to impair Hsp90 superchaperone complex for simultaneous downregulation of oncogenic proteins in pancreatic cancer cells. MTS assay showed that (-)-EGCG exhibited antiproliferative activity against pancreatic cancer cell line Mia Paca-2 in vitro with IC50 below 50 muM. (-)-EGCG increased caspase-3 activity up to 3-fold in a time- and concentration-dependent manner. Western blotting analysis demonstrated that (-)-EGCG induced downregulation of oncogenic Hsp90 client proteins by approximately 70-95%, including Akt, Cdk4, Raf-1, Her-2, and pERK. Co-immunoprecipitation showed that (-)-EGCG decreased the association of cochaperones p23 and Hsc70 with Hsp90 by more than 50%, while it had little effect on the ATP binding to Hsp90. Proteolytic fingerprinting assay confirmed direct binding between (-)-EGCG and the Hsp90 C-terminal domain. These data suggest that the binding of (-)-EGCG to Hsp90 impairs the association of Hsp90 with its cochaperones, thereby inducing degradation of Hsp90 client proteins, resulting antiproliferating effects in pancreatic cancer cells. Mol Pharm. 2009 Jul-Aug;6(4):1152-9. (Li Y, et al 2009)

Withanolide sulfoxide from Aswagandha roots inhibits nuclear transcription factor-kappa-B, cyclooxygenase and tumor cell proliferation.
Investigation of the methanol extract of Aswagandha (Withania somnifera) roots for bioactive constituents yielded a novel withanolide sulfoxide compound (1) along with a known withanolide dimer ashwagandhanolide (2) with an S-linkage. The structure of compound 1 was established by extensive NMR and MS experiments. Compound 1 was highly selective in inhibiting cyclooxygenase-2 (COX-2) enzyme by 60% at 100 microm with no activity against COX-1 enzyme. The IC(50) values of compound 1 against human gastric (AGS), breast (MCF-7), central nervous system (SF-268) and colon (HCT-116) cancer cell lines were in the range 0.74-3.63 microm. Both S-containing dimeric withanolides, 1 and 2, completely suppressed TNF-induced NF-kappaB activation when tested at 100 microm. The isolation of a withanolide sulfoxide from W. somnifera roots and its ability to inhibit COX-2 enzyme and to suppress human tumor cell proliferation are reported here for the first time. In addition, this is the first report on the abrogation of TNF-induced NF-kappaB activation for compounds 1 and 2. Phytother Res. 2009 Jul;23(7):987-92. (Mulabagal V, et al 2009)

Licorice and licochalcone-A induce autophagy in LNCaP prostate cancer cells by suppression of Bcl-2 expression and the mTOR pathway.
Licorice is a common Chinese medicinal herb with antitumor activity. Some components in licorice root have been shown to induce cell cycle arrest or apoptosis in cancer cells. This paper demonstrates for the first time that licorice Glycyrrhiza glabra and its component licochalcone-A (LA) can induce autophagy in addition to apoptosis in human LNCaP prostate cancer cells. Exposure of cells to licorice or LA resulted in several confirmed characteristics of autophagy, including the appearance of autophagic vacuoles revealed by monodansylcadaverine (MDC) staining, formation of acidic vesicular organelles (AVOs), and autophagosome membrane association of microtubule-associated protein 1 light chain 3 (LC3) characterized by cleavage of LC3 and its punctuate redistribution, as well as ultrastructural observation of autophagic vacuoles by transmission electron microscopy. Autophagy induction was accompanied by down-regulation of Bcl-2 and inhibition of the mammalian target of rapamycin (mTOR) pathway. In summary, licorice can induce caspase-dependent and autophagy-related cell death in LNCaP cells. J Agric Food Chem. 2009 Sep 23;57(18):8266-73. (Yo YT, et al 2009)

Resveratrol suppresses growth of human ovarian cancer cells in culture and in a murine xenograft model: eukaryotic elongation factor 1A2 as a potential target.
The eukaryotic elongation factor 1A2 (eEF1A2) is known to retain oncogenic potential and is recognized as a novel target for cancer prevention and therapy. Resveratrol (trans-3,4′,5-trihydroxystilbene), a phytoalexin present in grapes, has been reported to possess chemopreventive and chemotherapeutic activities. In the present study, we examined the growth-inhibitory effects of resveratrol in human ovarian cancer PA-1 cells, considering eEF1A2 as a potential molecular target. Pretreatment with resveratrol attenuated proliferation of serum-starved PA-1 cells stimulated with insulin or serum. Resveratrol also activated caspase-9, -7, and -3 and induced apoptosis in PA-1 cells in the presence of insulin or serum. Insulin or serum stimulation of PA-1 cells resulted in the marked induction of eEF1A2, which was suppressed by pretreatment with resveratrol. Moreover, resveratrol inhibited insulin- or serum-induced soft-agar colony formation in eEF1A2-transfected NIH3T3 cells. An antibody array directed to assess the phosphorylation of protein kinases revealed that treatment with insulin or serum induced the phosphorylation of Akt in PA-1 cells. Pharmacologic inhibition of Akt with LY294002 abrogated insulin- or serum-induced eEF1A2 expression and increased the caspase-3 activity. In another experiment, i.p. administration of resveratrol retarded the growth of PA-1 cell xenograft and the expression of eEF1A2 in athymic nude mice in association with decreased bromodeoxyuridine positivity, reduced expression of proliferating cell nuclear antigen, increased the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and caspase-3 staining, and diminished CD31 positivity. Taken together, eEF1A2 may be considered as a potential molecular target for the antiproliferative effects of resveratrol in PA-1 ovarian cancer cells. Cancer Res. 2009 Sep 15;69(18):7449-58. Epub 2009 Sep 8. (Lee MH, et al 2009)

Suppression of Heregulin-{beta}1/HER2-Modulated Invasive and Aggressive Phenotype of Breast Carcinoma by Pterostilbene via Inhibition of Matrix Metalloproteinase-9, p38 Kinase Cascade and Akt Activation.
Invasive breast cancer is the major cause of death among females and its incidence is closely linked to HER2 (human epidermal growth factor receptor 2) overexpression. Pterostilbene, a natural analog of resveratrol, exerts its cancer chemopreventive activity similar to resveratrol by inhibiting cancer cell proliferation and inducing apoptosis. However, the anti-invasive effect of pterostilbene on HER2-bearing breast cancer has not been evaluated. Here, we used heregulin-beta1 (HRG-beta1), a ligand for HER3, to transactivate HER2 signaling. We found that pterostilbene was able to suppress HRG-beta1-mediated cell invasion, motility and cell transformation of MCF-7 human breast carcinoma through down-regulation of matrix metalloproteinase-9 (MMP-9) activity and growth inhibition. In parallel, pterostilbene also inhibited protein and mRNA expression of MMP-9 driven by HRG-beta1, suggesting that pterostilbene decreased HRG-beta1-mediated MMP-9 induction via transcriptional regulation. Examining the signaling pathways responsible for HRG-beta1-associated MMP-9 induction and growth inhibition, we observed that pterostilbene, as well as SB203580 (p38 kinase inhibitor), can abolish the phosphorylation of p38 mitogen-activated protein kinase (p38 kinase), a downstream HRG-beta1-responsive kinase responsible for MMP-9 induction. In addition, HRG-beta1-driven Akt phosphorylation required for cell proliferation was also suppressed by pterostilbene. Taken together, our present results suggest that pterostilbene may serve as a chemopreventive agent to inhibit HRG-beta1/HER2-mediated aggressive and invasive phenotype of breast carcinoma through down-regulation of MMP-9, p38 kinase and Akt activation. Evid Based Complement Alternat Med. 2009 Jul 16. [Epub ahead of print] (Pan MH, et al 2009)


Low concentrations of diindolylmethane, a metabolite of indole-3-carbinol, protect against oxidative stress in a BRCA1-dependent manner.
The indole-3-carbinol (I3C) metabolite 3,3′-diindolylmethane (DIM) is a proposed cancer prevention agent for various tumor types, including breast cancer. Here, we show that DIM up-regulates expression of the tumor suppressor protein BRCA1 in carcinoma and normal cell types. Up-regulation of BRCA1 was dose and time dependent, and it was observed at physiologically relevant micromolar and submicromolar DIM concentrations when cells were exposed for 72 hours. Treatment with the parent compound (I3C) or DIM (1 micromol/L) protected against cell killing due to H(2)O(2) and other oxidants, and the protection was abrogated by knockdown of BRCA1. DIM stimulated signaling by the antioxidant transcription factor NFE2L2 (NRF2) through the antioxidant response element in a BRCA1-dependent manner. We further showed that DIM rapidly stimulated phosphorylation of BRCA1 on Ser (1387) and Ser (1524) and that these phosphorylations are required for protection against oxidative stress. DIM-induced phosphorylation of BRCA1 on Ser (1387) was dependent on ataxia-telangiectasia mutated. Finally, in our assay systems, H(2)O(2)-induced cell death was not due to apoptosis. However, a significant component of cell death was attributable to autophagy, and both DIM and BRCA1 inhibited H(2)O(2)-induced autophagy. Our findings suggest that low concentrations of DIM protect cells against oxidative stress via the tumor suppressor BRCA1 by several distinct mechanisms. Cancer Res. 2009 Aug 1;69(15):6083-91. Epub 2009 Jul 21. (Fan S, et al 2009)

The dietary phytochemical indole-3-carbinol is a natural elastase enzymatic inhibitor that disrupts cyclin E protein processing.
Indole-3-carbinol (I3C), a naturally occurring component of Brassica vegetables, such as broccoli, cabbage, and Brussels sprouts, induces a G(1) cell-cycle arrest of human breast cancer cells, although the direct cellular targets that mediate this process are unknown. Treatment of highly invasive MDA-MB-231 breast cancer cells with I3C shifted the stable accumulation of cyclin E protein from the hyperactive lower-molecular-mass 35-kDa form that is associated with cancer cell proliferation and poor clinical outcomes to the 50-kDa cyclin E form that typically is expressed in normal mammary tissue. An in vitro cyclin E processing assay, in combination with zymography, demonstrated that I3C, but not its natural dimer, 3,3′-diindolylmethane, disrupts proteolytic processing of the 50-kDa cyclin E into the lower-molecular-mass forms by direct inhibition of human neutrophil elastase enzymatic activity. Analysis of elastase enzyme kinetics using either cyclin E or N-methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroanalide as substrates demonstrated that I3C acts as a noncompetitive inhibitor of elastase activity with an inhibitory constant of approximately 12 microM. Finally, siRNA ablation of neutrophil elastase protein production in MDA-MB-231 cells mimicked the I3C-disrupted processing of the 50-kDa cyclin E protein and the indole-induced cell-cycle arrest. Taken together, our results demonstrate that elastase is the first identified specific target protein for I3C and that the direct I3C inhibition of elastase enzymatic activity implicates the potential use of this indole, or related compounds, in targeted therapies of human breast cancers where high elastase levels are correlated with poor prognosis. Proc Natl Acad Sci U S A. 2008 Dec 16;105(50):19750-5. Epub 2008 Dec 8. (Nguyen HH, et al 2008)

Indole-3-carbinol inhibits Sp1-induced matrix metalloproteinase-2 expression to attenuate migration and invasion of breast cancer cells.
Indole-3-carbinol (I3C), a major indole metabolite in cruciferous vegetables, has been shown to inhibit invasion of breast cancer cells. This study addressed the effect of I3C on the expression of matrix metalloproteinases (MMPs) and clarified the underlying mechanism. Migration, invasion, and MMP-2 activity of MCF-7 breast cancer cells were dose-dependently inhibited by I3C. In addition, the MMP-2 mRNA level was also reduced by I3C. Promoter deletion and mutation analysis suggested that I3C inhibited MMP-2 gene transcription via the -85/-7 bp promoter region and the Sp1 transcription factor binding site located within the -72/-64 bp promoter region was important for the inhibition. Chromatin immunoprecipitation assay confirmed that Sp1 proteins constitutively bound to this consensus sequence in vivo and that the binding was attenuated by I3C. In addition, I3C inhibited the extracellular signal-regulated kinase (ERK) signaling pathway in MCF-7 cells. The results suggest that I3C inhibits MMP-2 expression by blocking the ERK/Sp1-mediated gene transcription to attenuate migration and invasion of breast cancer cells. J Agric Food Chem. 2009 Jan 14;57(1):76-82. (Hung WCChang HC. 2009)

Indole-3-carbinol inhibits MDA-MB-231 breast cancer cell motility and induces stress fibers and focal adhesion formation by activation of Rho kinase activity.Indole-3-carbinol (I3C), a phytochemical derived from cruciferous vegetables such as broccoli and Brussels sprouts, has potent antiproliferative effects in human breast cancer cells and has been shown to decrease metastatic spread of tumors in experimental animals. Using chemotaxis and fluorescent-bead cell motility assays, we demonstrated that I3C significantly decreased the in vitro migration of MDA-MB-231 cells, a highly invasive breast cancer cell line. Immunofluorescence staining of the actin cytoskeleton revealed that concurrent with the loss of cell motility, I3C treatment significantly increased stress fiber formation. Furthermore, I3C induced the localization of the focal adhesion component vinculin and tyrosine-phosphorylated proteins to the cell periphery, which implicates an indole-dependent enhancement of focal adhesions within the outer boundary of the cells. Coimmunoprecipitation analysis of focal adhesion kinase demonstrated that I3C stimulated the dynamic formation of the focal adhesion protein complex without altering the total level of individual focal adhesion proteins. The RhoA-Rho kinase pathway is involved in stress fiber and focal adhesion formation, and I3C treatment stimulated Rho kinase enzymatic activity and cofilin phosphorylation, which is a downstream target of Rho kinase signaling, but did not increase the level of active GTP-bound RhoA. Exposure of MDA-MB-231 cells to the Rho kinase inhibitor Y-27632, or expression of dominant negative RhoA ablated the I3C induced formation of stress fibers and of peripheral focal adhesions. Expression of constitutively active RhoA mimicked the I3C effects on both processes. Taken together, our data demonstrate that I3C induces stress fibers and peripheral focal adhesions in a Rho kinase-dependent manner that leads to an inhibition of motility in human breast cancer cells. Int J Cancer. 2009 May 15;124(10):2294-302. (Brew CT, et al 2009)

OSU-A9, a Potent Indole-3-Carbinol Derivative, Suppresses Breast Tumor Growth by Targeting the Akt-NF-{kappa}B Pathway and Stress Response Signaling.
The molecular heterogeneity of human tumors challenges the development of effective preventive and therapeutic strategies. To overcome this issue, a rational approach is the concomitant targeting of clinically relevant cellular abnormalities with combination therapy or a potent multi-targeted agent. OSU-A9 is a novel indole-3-carbinol derivative that retains the parent compound’s ability to perturb multiple components of oncogenic signaling, but provides marked advantages in chemical stability and antitumor potency. Here, we show that OSU-A9 exhibits two-orders-of-magnitude greater potency than indole-3-carbinol in inducing apoptosis in various breast cancer cell lines with distinct genetic abnormalities, including MCF-7, MDA-MB-231, and SKBR3, with IC(50) in the range of 1.2 – 1.8 muM vis-à-vis 200 muM for indole-3-carbinol. This differential potency was paralleled by OSU-A9’s superior activity against multiple components of the Akt-NF-kappaB and stress response signaling pathways. Notable among these were the increased estrogen receptor beta/estrogen receptor alpha expression ratio, reduced expression of HER2 and CXCR4, and the upregulation of arylhydrocarbon receptor expression and its downstream target Nrf2. Nonmalignant MCF-10A cells were resistant to OSU-A9’s antiproliferative effects. Daily oral administration of OSU-A9 at 25 and 50 mg/kg for 49 days significantly inhibited MCF-7 tumor growth by 59% and 70%, respectively, without overt signs of toxicity or evidence of induced hepatic biotransformation enzymes. In summary, OSU- A9 is a potent, orally bioavailable inhibitor of the Akt-NF-kappaB signaling network, targeting multiple aspects of breast tumor pathogenesis and progression. Thus, its translational potential for the treatment or prevention of breast cancer warrants further investigation. Carcinogenesis. 2009 Aug 25. [Epub ahead of print] (Weng JR, et al 2009)

3,3′-diindolylmethane induction of p75NTR-dependent cell death via the p38 mitogen-activated protein kinase pathway in prostate cancer cells.
The p75(NTR) functions as a tumor suppressor in prostate epithelial cells, where its expression declines with progression to malignant cancer. Previously, we showed that treatment with the nonsteroidal anti-inflammatory drug, indomethacin, induced p75(NTR) expression in the T24 cancer cell line leading to p75(NTR)-mediated decreased survival. Utilizing the indole moiety of indomethacin as a pharmacophore, we identified in rank-order with least efficacy, ketorolac, etodolac, indomethacin, 5-methylindole-3-acetic acid, indole-3-carbinol, and 3,3′-diindolylmethane (DIM) exhibiting greatest activity for induction of p75(NTR) levels and inhibition of cell survival. Prostate (PC-3, DU-145) and bladder (T24) cancer cells were more sensitive to DIM induction of p75(NTR)-associated loss of survival than breast (MCF7) and fibroblast (3T3) cells. Transfection of the PC-3 prostate cell line with a dominant-negative form of p75(NTR) before DIM treatment significantly rescued cell survival demonstrating a cause and effect relationship between DIM induction of p75(NTR) levels and inhibition of survival. Furthermore, siRNA knockdown of the p38 mitogen-activated protein kinase (MAPK) protein prevented induction of p75(NTR) by DIM in the PC-3 prostate cell line. DIM treatment induced phosphorylation of p38 MAPK as early as within 1 minute. Collectively, we identify DIM as an indole capable of inducing p75(NTR)-dependent apoptosis via the p38 MAPK pathway in prostate cancer cells. Cancer Prev Res (Phila Pa). 2009 Jun;2(6):566-71. Epub 2009 May 26 (Khwaja FSWynne SPosey IDjakiew D. 2009)

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Compassionate Acupuncture and Healing Arts, providing craniosacral acupuncture, herbal and nutritional medicine in Durham, North Carolina. Phone number 919-309-7753.

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One Response to Herbs, Herbal Compounds and Nutrients that Synergize with Chemotherapeutic Agents

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