Chemoprevention of rat prostate carcinogenesis by diallyl disulfide, an organosulfur compound of garlic

Diallyl disulfide (DADS), an important component of garlic (Allium sativam) has been demonstrated to exert a potential chemopreventive activity against human cancers. DADS inhibits proliferation of both androgen dependent and independent prostate cancer cells in vitro. However there is no report available on the role of DADS on prostate cancer initiation in in vivo model. So the present chemoprevention study was conducted to evaluate the activity of diallyl disulfide as an anticancer agent in prostate carcinogenesis of male Sprague-Dawley rats. Testosterone and N-Methyl N-Nitroso Urea (MNU) were used to induce prostate carcinogenesis that involves a multi step process like, hyperplasia, dysplasia and prostatic intraepithelial neoplasia (PIN). The rats were induced prostate carcinogenesis by injection of testosterone and single dose of MNU and again the testosterone was continued throughout the experimental period. Forty percentage of animals carried PIN in dorsolateral prostate, while dysplasia and hyperplasia (55 to 65%) were common in ventral as well as dorsolateral prostates of the hormone and carcinogen treated rats. Rats treated with hormone and carcinogen along with DADS developed PIN at incidence of 10% in the ventral and dorsolateral prostates about 20 to 10%. Dysplasia and hyperplasia were less common in these rats. The results of this study provide evidence that DADS may have chemopreventive activity in rat prostate carcinogenesis.