Black Cohosh May Make Breast Cancer Drug More Toxic Mon Apr 7 NEW YORK (Reuters Health) - Women with breast cancer who are undergoing chemotherapy may want to avoid black cohosh, the herbal remedy often used to treat menopausal symptoms such as hot flashes, according to Connecticut researchers In a new study of laboratory-grown breast cancer cells, the herb seemed to increase the toxicity of the commonly used chemotherapy drugs doxorubicin (Adriamycin) and docetaxel (Taxotere), but not a third, cisplatin. "We saw this with three different commercial black cohosh extracts," said Dr. Sara Rockwell of Yale University School of Medicine in New Haven, Connecticut. The suggestion that black cohosh may make these anticancer drugs more potent than they already are could be "a good thing or a bad thing," Rockwell said. "If this were an effect just on the tumor cells, that would be a good thing because it would mean you get more antitumor effect for a person on black cohosh," she said. "On the other hand, Adriamycin is used in doses that are nearly toxic -- it wipes out the bone marrow and is very close to the limit of heart toxicity. A substantial number of patients treated with Adriamycin show serious heart injury after treatment and if black cohosh increased that it could make this drug lethal." More research is needed to determine if this is true for patients -- results in laboratory cells may not mimic what happens in the body, a much more complex situation compared with a carefully controlled experiment. Rockwell's team focused their studies on black cohosh because they noticed that many women who went off hormone replacement therapy (HRT) when they were diagnosed with breast cancer began taking this particular herb during chemotherapy and radiation therapy. "Many women assume that black cohosh is a safe and effective natural remedy for menopausal symptoms," she told Reuters Health. But how it interacts with other drugs is unclear. Rockwell's team grew breast cancer cells in culture and then exposed them to black cohosh at concentrations found in products on the drug store shelf. Then, in separate experiments, they exposed the cells to radiation or to three drugs commonly used to treat breast cancer -- Adriamycin, Taxotere, and cisplatin. In the radiation experiment, they saw no changes in the breast cancer cells. "Black cohosh did not change the response of the breast cancer cells to the radiation," Rockwell said. And the remedy did not influence laboratory-grown breast cancer cells in the absence of chemotherapy drugs, or affect the growth of breast cancer tumors in mice fed the herbal remedy. "Up to 80% of cancer patients may be taking one or more vitamins, minerals, or herbs," Rockwell said. "Many of these agents are not well standardized and they are not regulated by FDA ." The findings were scheduled to be presented this week at the American Association for Cancer Research's 94th Annual Meeting in Toronto, but meeting planners canceled the event citing growing concern about cases of severe acute respiratory syndrome (SARS) in the city. Breast Cancer News is brought to you by BREAST CANCER OPTIONS, part of the Mid Hudson Options Project, a grassroots Breast Cancer Health Advocacy, Support and Activist Group. Growth inhibitory activity of extracts and purified components of black cohosh on human breast cancer cells. Einbond LS, Shimizu M, Xiao D, Nuntanakorn P, Lim JT, Suzui M, Seter C, Pertel T, Kennelly EJ, Kronenberg F, Weinstein IB. Abstract: The purpose of this study was to determine whether black cohosh contains constituents that inhibit the growth of human breast cancer cells, and therefore might eventually be useful in the prevention or treatment of breast cancer. Black cohosh rhizomes were extracted with methanol/water and fractionated by solvent-solvent partitioning to yield three fractions: hexane, ethyl acetate and water. The ethyl acetate fraction displayed the highest potency in two cell-based assays, growth inhibition and cell cycle analysis. This fraction inhibited growth of both the ER(+) MCF7 and ER(-)MDA-MB-453 human breast cancer cell lines with IC(50) values of about 20 and 10 micro g/ml, respectively. It also induced cell cycle arrest at G1 when tested at 30 micro g/ml and at G2/M at 60 micro g/ml in MCF7 cells. This suggests that the extract contains a mixture of components with the more active (or more abundant) causing G1 arrest and the less active causing G2/M arrest. We then examined specific components in this extract. The triterpene glycoside fraction obtained by polyamide column chromatography, and the specific triterpene glycosides actein, 23-epi-26-deoxyactein and cimiracemoside A, inhibited growth of the MCF7 human breast cancer cells and induced cell cycle arrest at G1. The most potent compound, actein, decreased the level of cyclin D1, cdk4 and the hyperphosphorylated form of the pRb protein and increased the level of p21(cip1) in MCF7 cells, changes that may contribute to the arrest in G1. Further studies are in progress to identify the mechanisms by which actein and related compounds present in black cohosh inhibit growth of human breast cancer cells. Breast Cancer Res Treat. 2004 Feb;83(3):221-31. Thanks to www.dreliaz.com Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.