Antioxidant and radical scavenging properties in vitro of polyphenolic extracts from red wine

Background & Aims Red, wine polyphenols inhibit chemically-induced oxidativ e DNA damage in vivo in experimental animals through a mechanism which is s till unclear. On this basis, we tried to clarify the mechanisms of inhibiti on of DNA oxidation in vitro by wine extracts containing monomeric and poly meric phenols (WE) and monomer-free complex polyphenols and tannins (WCPT) from red wine. Methods Oxidative DNA damage was induced by incubating DNA w ith GSH/Fe3+ or cumene hydroperoxide (CumOOH) in vitro and using 8-OH-2-deo xyguanosine (8-OHdG) levels as a measure of DNA oxidation. Levels of 8-OHdG were determined by HPLC coupled with electrochemical detector (ESA). Resul ts and conclusions WCPT arid WE, at muM concentrations, reduced concentrati on-dependently oxidative DNA, damage induced by GSH/Fe3+. WCPT and WE also reduced DNA oxidation by CumOOH. In conclusion, complex polyphenols and tan nin extracts from red wine, with or without small molecular phenols, preven t oxidative DNA damage through a dual mechanism, iron binding and direct fr ee radical scavenging.