Alcohol hinders the Anti-Carcinogenic effect of Resveratrol in the Colon of rats

Abstract

Resveratrol (RESV), a polyphenol present in wine and other natural sources, has potent anti-oxidant and chemopreventive effect against various types of cancer by multiple mechanisms of action. On the other hand, ethanol, which is also one important component of wine, is associated with increased oxidative stress and risk of cancer in general, including the colonic cancer. It is unknown whether the anti-oxidant and anti-carcinogenic effects of RESV could be counterbalanced by alcohol in vivo. Thus, the present study evaluated the anti-neoplastic action of RESV, pure or associated with ethanol on the colon carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in rats. It was performed a detailed analysis of aberrant crypt foci (ACF) formation and the systemic oxidative stress through malondialdehyde (MDA) dosage. The inflammatory process, which is associated to the colonic carcinogenesis, was estimated by the immune-expression of cyclooxigenase-2 (COX-2). Our experiments were performed in 32 wistar rats, divided into four groups: the group C was the control, the group M received MNNG (5mg/ml), the group MR received MNNG and RESV (1mg/kg/day) and the group MRA received RESV and alcohol (0,377g/kg/day). As a result, RESV decreased the number of ACF and COX-2 expression, but these effects were abolished by the alcohol. RESV reduced the production of MDA in all treated groups, evidencing that its systemic antioxidant effect was also present in the animals treated with alcohol. It was concluded that alcohol hindered the anti-carcinogenic effects of RESV. This effect of alcohol should be attributed to its pro-inflammatory effects, which have avoided the anti-inflammatory properties of RESV.