Resveratrol, a phytoestrogen found in a variety of plant foods, has been found to inhibit the growth and proliferation of various type of breast cancer in numerous cell and animal studies. Resveratrol has also been show to inhibit aromatase activity (in which androgens are converted to estrogens in the body), which is important for reducing the growth-stimulatory effects of estrogen in estrogen receptor positive (ER+) breast cancer. In addition, resveratrol has been shown to increase the effectiveness of a variety of breast cancer treatments and to reduce the heart damage caused by the chemotherapy drug Adriamycin (doxorubicin). Now a new study has demonstrated how resveratrol increases the treatment effects of Adriamycin in both hormone receptor positive (ER+/PR+) and triple negative (ER-/PR-/HER2-) breast cancer cells.
Sources of resveratrol
The best sources of resveratrol for breast cancer patients and survivors are red grapes and grape juice, blueberries and cranberries. Other significant dietary sources of resveratrol such as red wine and peanuts are not recommended.
Resveratrol supplements should be avoided because safe and effective dosages have not been established. One study reported that resveratrol at the low concentrations that could realistically result from supplementation promoted mammary tumor growth and metastasis in a mouse model of breast cancer. Another study found that the combination of zinc plus resveratrol significantly increased the rate of carcinogenesis and increased number of carcinogen-induced mammary tumors in a rat model of breast cancer.
Latest research finds resveratrol potentiates Adriamycin
The study referenced at the beginning of this news story was designed to investigate the synergistic combination of resveratrol and Adriamycin in breast cancer cells and an animal model of cancer. The authors first assessed the cytotoxicity and impact on apoptosis, cell migration and colony formation of resveratrol and Adriamycin alone and in combination in ER+/PR+ MCF-7 cells and triple negative MDA-MB-231 cells. The combination of resveratrol plus Adriamycin was found to have potent growth inhibition effects, with an approximate 2.5 fold dose advantage over single treatment. The combination also significantly reduced the wound healing and clonogenic potential (the ability to proliferate indefinitely) of breast cancer cells, in addition to inhibiting the cellular inflammatory response.
The authors then assessed the combination of Adriamycin and resveratrol in tumor-bearing mice. Combined treatment with Adriamycin (5 mg/kg b.wt) and resveratrol (10 mg/kg b.wt) was found to inhibit tumor volume and significantly increase life span. The authors conclude that resveratrol appears to chemosensitizes Adriamycin by inhibiting breast cancer cell proliferation and invasion, and inducing apoptosis (programmed call death) through suppression of chronic inflammation and autophagy.
Please see our article on what to eat during Adriamycin treatment for more information.