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.
Wang
Jun
J
Department of Pharmacology and Toxicology, 1670 University Boulevard, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Eltoum
Isam-Eldin
IE
Lamartiniere
Coral A
CA
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