Dietary genistein suppresses chemically induced prostate cancer in Lobund-Wistar rats.
Epidemiological reports suggest that Asians consuming a diet high in soy have a low incidence of clinically manifested prostate cancer. We have tested the hypothesis that life-time exposure to genistein, the primary isoflavone component of soy, is responsible for this protective effect. Lobund-Wistar rats were exposed to 0, 25 and 250 mg genistein/kg AIN-76A diet, starting at conception and continued until necropsy at 11 months. Male offspring were injected s.c. with Flutamide on days 50-66 and with testosterone on days 67-69, injected with N-methylnitrosourea (NMU) into the dorsal prostate on day 70, and given testosterone implants, starting at day 77. Genistein in the diet inhibited the development of NMU-induced prostate invasive adenocarcinomas, in a dose-dependent manner. Genistein did not alter body, prostate and testes weights. Male rats fed 0, 25 and 250 mg genistein/kg diet had serum genistein concentrations of 9, 60 and 861 pmol/ml, and prostate genistein concentrations of 85, 230 and 775 pmol/g tissue. We conclude that lifetime dietary genistein protected against chemically induced prostate cancer development in rats.
Department of Pharmacology and Toxicology, 1670 University Boulevard, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Jun
J
Wang
Isam-Eldin
IE
Eltoum
Coral A
CA
Lamartiniere
D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D004032:Diet; D019833:Genistein / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008297:Male; D008770:Methylnitrosourea; D011471:Prostatic Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D051381:Rats; D017208:Rats, Wistar
D016588:Anticarcinogenic Agents; D008770:Methylnitrosourea; D019833:Genistein