Lipid antioxidant properties of quercetin in vitro.

The effect of quercetin on iron-catalyzed hepatic microsomal lipid peroxidation was investigated. Quercetin was shown to be a potent inhibitor of iron-induced lipid peroxidation with a I50 of 0.2 mM. The inhibitory effects of quercetin were dependent on incubation time, protein concentration and iron content in the incubation mixture. Since quercetin does not interact with malonyl-aldehyde it can be concluded that the inhibition of iron induced lipid peroxidation is due to lipid antioxidant property and this may serve as a model for the study by which "free" iron may initiate peroxidation in vivo.