Growth inhibition of human breast cancer cells by herbs and phytoestrogens

Epidemiologic studies have suggested that consumption of phytoestrogen-rich foods may protect against breast cancer, and phytoestrogens such as genist ein have been reported to both inhibit and stimulate the growth of some hum an breast cancer cells. The phytoestrogens genistein, daidzein, biochanin A , and coumestrol were tested and found to inhibit serum-stimulated growth i n both T-47D and MCF-7 breast cancer cells at 10-100 mu M. Extracts of seve ral estrogenic herbs, including hops, black cohosh and vitex, inhibited gro wth of T-47D cells. These in vitro results suggest that certain herbs and p hytoestrogens may have potential in the prevention of breast cancer.