The influence of wine polyphenols on reactive oxygen and nitrogen species production by rat macrophages RAW 264.7

The aim was to study the antioxidant properties of four winepolyphenols (flavonoids catechin, epicatechin, and quercetin, andhydroxystilbene resveratrol). All three flavonoids exertedsignificant and dose-dependent scavenging effects againstperoxyl radical and nitric oxide in chemical systems. Thescavenging effect of resveratrol was significantly lower. Allpolyphenols decreased production of reactive oxygen species(ROS) by RAW264.7 macrophages. Only quercetin quenched ROSproduced by lipopolysaccharide-stimulated RAW264.7macrophages incubated for 24 h with polyphenols. Quercetin andresveratrol decreased the release of nitric oxide by these cells ina dose-dependent manner which corresponded to a decrease iniNOS expression in the case of quercetin. In conclusion, thehigher number of hydroxyl substituents is an important structuralfeature of flavonoids in respect to their scavenging activityagainst ROS and nitric oxide, while C-2,3 double bond (present inquercetin and resveratrol) might be important for inhibition ofROS and nitric oxide production by RAW 264.7 macrophages.