Soy Extract Slows Prostate Cancer Growth in Mice
More evidence is accumulating that altered estrogen metabolism in men can lead to prostate problems. This would be the unhealthy conversion of estrogen into a more dangerous by product, potentially irritating the prostate. It makes sense that soy would attunate these effects. Cruciferous vegetables high in indole-3-carbinol (brussel sprouts, broccoli) would also aid the proper metabolism of estrogens.
American Urological Association meeting in Anaheim, California The soy extract, genistein, slows prostate cancer growth in mice, suggesting a possible role as an adjunct to conventional therapy or as a preventive agent, according to Dr. Ralph deVere White, director of the University of California Davis Cancer Center, who presented his findings on Saturday at the American Urological Association meeting in Anaheim, California. Dr. White’s team treated PC-3 prostate cancer cells with aglycone isoflavones (GCP), a proprietary form of genistein that functions as a general protein kinase inhibitor, or with AHCC, a non-specific immune modulator found in shiitake mushrooms. The investigators also tested the two compounds in combination. GCP reduced PC-3 cell growth in a dose-dependent fashion. It also reduced vascular endothelial growth factor production, increased p21 production and induced apoptosis. AHCC enhanced GCP’s effects, but had no effect on prostate cancer cell growth when used alone. Armed with this information, Dr. White’s team subcutaneously inoculated 32 five-week-old nude mice with the treated prostate cancer cells. Some of the mice also received water or water plus genistein daily. “There was a significant drop in the cancer growth of the mice fed genistein in water,” Dr. White told Reuters Health. He said his team plans to continue their studies of GCP in a clinical trial of men with prostate cancer who have failed radical prostatectomy or radiation therapy and have a slow rising PSA to see if the extract can lower the PSA. “If it can, it might be used in an adjuvant fashion to make radiation therapy more effective and ultimately as a chemopreventive agent. But that is a long way off,” he added.