A recently published study investigated the possibility that trans-resveratrol may be a safer alternative than hormone replacement therapy (HRT) in menopausal women.
Estrogens used as hormone replacement therapy to alleviate menopausal symptoms have been found to increase the risk of breast cancer, thus alternate therapies are needed. It is estimated that 6,000 U.S. women reach menopause each day, totaling more than 2 million women per year. Most women spend 1/3 to 1/2 of their life in the post-menopausal phase; currently there are approximately 45.6 million post-menopausal American women.
Phytoestrogens are naturally occurring plant compounds that are structurally similar to the estrogens made in the body. Phytoestrogens can elicit either mild estrogenic or anti-estrogenic effects. In this new study, researchers analyzed the effects of several well-known phytoestrogens including daidzein, genistein, coumestrol, trans-resveratrol and glycitein on breast cancer cells to evaluate the safety of these compounds. The researchers also compared these effects to 17-beta-estradiol (E2), the primary type of estrogen produced in the body.
The researchers found that daidzein, genistein, coumestrol, and trans-resveratrol significantly increased transcriptional activity, the copying of the DNA, up to a level similar to that of 17-beta-estradiol (E2). Also, the study showed that while 17-beta-estradiol increased cell growth, trans-resveratrol and glycitein reduced cell growth in the breast cancer cells. Trans-resveratrol also significantly enhanced p53-dependent transcriptional activity while decreasing NF-kappaB-dependent transcriptional activity. p53 is a transcription factor that plays a role in regulation of the cell cycle and functions as a tumor suppressor that is involved in preventing cancer, while NF-kappa-B is a transcription factor that signals the beginning of inflammatory responses, which is activated by cellular stress. Furthermore, genistein, trans-resveratrol and glycitein all increased apoptosis (programmed cell death) in the breast cancer cells, and trans-resveratrol decreased the ratio of anti-apoptotic to pro-apoptotic proteins better than genistein or glycitein.
The researchers concluded, "Thus, trans-resveratrol might be the most promising candidate for HRT and chemoprevention of breast cancer due to its estrogenic activity and high anti-tumor activity."
Reference:
Sakamoto T, Horiguchi H, Oguma E, Kayama F. Effects of diverse dietary phytoestrogens on cell growth, cell cycle and apoptosis in estrogen-receptor-positive breast cancer cells. J Nutr Biochem. 2009 Oct 2. Published Online Ahead of Print.
