Antioxidant activity of quercetin and myricetin in liposomes

Abstract

The antioxidant activity during storage at 30°C of quercetin, myricetin and α-tocopherol in small unilamellar liposomes has been investigated. Myricetin was more effective than α-tocopherol as an antioxidant in liposomes under all conditions studied. At pH 5.4 with a concentration of 10 −2 mol/mol phospholipid, myricetin has been shown to be the strongest antioxidant followed by quercetin and α-tocopherol. Cupric chloride and ferric chloride strongly reduced the antioxidant activity of myricetin and quercetin with cupric chloride causing a stronger reduction in activity than ferric chloride. At a pH of 7.4, quercetin was less effective than α-tocopherol at a concentration of 10 −2 mol/mol phospholipid, but it’s activity increased more strongly with concentration and it was very effective at a concentration of 5×10 −2 mol/mol phospholipid.