Progesterone inhibits prostate cancer cells via inhibition of 5-alpha reductase, reducing the conversion of testosterone into dihydrotestosterone. - GreenMedInfo Summary
A new approach to prostate cancer.
J Pharm Pharmacol. 1989 Jul;41(7):488-9. PMID: 2570857
Growth of androgen-dependent human prostatic adenocarcinoma implanted in the nude mouse (Honda tumour), is inhibited by 6-methyleneprogesterone. This steroid is a potent inhibitor of both rat and human prostatic 5 alpha-reductase in-vitro. In-vivo, at the studied dose level, it reduces metabolic conversion of testosterone to dihydrotestosterone with minimal effects upon circulating LH and testosterone. These data support the hypothesis that dihydrotestosterone and not testosterone is the main trophic androgen of the human prostatic neoplasm.