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

The aim was to study the antioxidant properties of four wine polyphenols (flavonoids catechin, epicatechin, and quercetin, and hydroxystilbene resveratrol). All three flavonoids exerted significant and dose-dependent scavenging effects against peroxyl radical and nitric oxide in chemical systems. The scavenging effect of resveratrol was significantly lower. All polyphenols decreased production of reactive oxygen species (ROS) by RAW264.7 macrophages. Only quercetin quenched ROS produced by lipopolysaccharide-stimulated RAW264.7 macrophages incubated for 24 h with polyphenols. Quercetin and resveratrol decreased the release of nitric oxide by these cells in a dose-dependent manner which corresponded to a decrease in iNOS expression in the case of quercetin. In conclusion, the higher number of hydroxyl substituents is an important structural feature of flavonoids in respect to their scavenging activity against ROS and nitric oxide, while C-2,3 double bond (present in quercetin and resveratrol) might be important for inhibition of ROS and nitric oxide production by RAW 264.7 macrophages.