Herb World News Online

Herb Research Foundation


 Top News  |  World  |  Science  |  Research Reviews  |  Politics  |  Industry  |  Features
 Science News

Milk thistle

Silymarin marianum

Specific evidence for the role of silibinin in prostate cancer treatment

Research suggests that the lower incidence of prostate cancer among Asians living in Asia (compared with Asians living in the United States and eating a standard Western diet) may be related to a dietary lowering of biologically active androgen. Further evidence to support this concept comes from the observation that more than 75% of prostate cancers are androgen-dependent at initial diagnosis. Prostate specific antigen (PSA), an important androgen-regulated gene in both normal and cancerous prostate cells, has been shown to be a particularly sensitive marker in the diagnosis and treatment of the disease. The present study investigated the possible role of the flavonoid antioxidant silibinin, a component of milk thistle, in the regulation of this gene. Like other phytoestrogens, silibinin is thought to have the potential to affect the progression of hormone-dependent cancers. In this laboratory study, silibinin was effective in decreasing intracellular and secreted levels of PSA under serum- and androgen-induced conditions while retarding cell growth by arresting the G1 phase of the growth cycle. Silibinin treatment resulted in significant neuroendocrine differentiation of the cancer cells, but not apoptosis. Further, silibinin did not exert any apparent effects on normal cells, only cancer cells. Decreased PSA levels caused by silibinin may be attributable either to an inhibitory effect by silibinin against PSA protein expression or by a direct inhibition of androgen receptor-mediated PSA expression.

Zi X, Agarwal R. Silibinin decreases prostate-specific antigen with cell growth inhibition via G1 arrest, leading to differentiation of prostate carcinoma cells: implications for prostate cancer intervention. Proc Natl Acad Sci USA 1999; 96: 7490-7495.

 Top News  |  World  |  Science  |  Research Reviews  |  Politics  |  Industry  |  Features

Back to the Herb World News Online Front Page

Visit the Herb World News Archives

© 2003 by Herb Research Foundation, Boulder, CO, USA.

Main Page