Daidzein reduces growth of breast tumors in rodents
This study was designed to examine the anti-cancer effects of the isoflavone daidzein and its metabolites on rodents. Previous epidemiological studies have demonstrated that soy consumption reduces the risk of several diseases, including breast cancer. Soybeans contain high levels of isoflavones (daidzein and genistein) which have been shown to possess estrogenic responses by binding to estrogen receptors.
Scientists at the State University of New York exposed rats with tumors to daidzein and its metabolite equol in doses equivalent to tamoxifen, a popular anti-cancer drug used for the treatment of estrogen receptor positive breast cancer in pre- and post-menopausal women.
Many studies have been conducted on this subject but this one was the first to use oral treatment at human equivalent doses. The scientist first implanted the rodents with mammary tumors and human breast cancer tissue and treated them with an estrogen pellet. Then they observed the growth of the tumors for several weeks. They also determined the expression of caspace-3. They found that oral treatment of the mice with daidzein or equol suppressed the growth of the mammary tumors and human breast cancer tissue, even more effectively than tamoxifen. Daidzein or equol induced strong apoptosis of the cancer cells.
The study concluded that daidzein and equol could be used in new drugs to combat breast cancer and that daily consumption of the isoflavone may protect against breast cancer.
Anti-breast cancer potential of daidzein in rodents. Life Science. 2012 Oct 5;91(11-12):415-9.