Effect of complex polyphenols and tannins from red wine (WCPT) on chemically induced oxidative DNA damage in the rat

Background: Flavonoids are polyphenolic antioxidants occuring in vegetables and fruits as well as beverages such as tea and wine which have been thoug ht to influence oxidative damage. Aim of the study: We wanted to verify whether a complex mixture of wine tan nins (wine complex polyphenols and tannins, WCPT) prevent chemically-induce d oxidative DNA damage in vivo. Methods: Oxidative DNA damage was evaluated by measuring the ratio of 8-hyd roxy-2'-deoxyguanosine (8OHdG)/2-deoxyguanosine (2dG) x 10(-6) in hydrolyze d DNA using HPLC coupled with electrochemical and UV detectors. Results: We treated rats with WCPT (57 mg/kg p.o.) for 14 d, a dose 10-fold higher than what a moderate wine drinker would be ex-posed to. WCPT admini stration significantly reduced the ratio of 8OHdG/2dG x 10(-6) in liver DNA obtained from rats treated with 2-nitropropane (2NP) relative to controls administered 2NP only (33.3 +/- 2.5 vs. 44.9 +/- 3.2 x 10(-6) 2dG; mu +/- S E; p<0.05). On the contrary, pretreatment with WCPT for 10 d did not protec t the colon mucosa from oxidative DNA damage induced by 1,2-dimethylhydrazi ne (DMH). 2NP and DMH are hepatic and colon carcinogens, respectively, capa ble of inducing oxidative DNA damage. Conclusions: WCPT have protective action against some types of chemically-i nduced oxidative DNA damage in vivo.