Abstract:The inhibitory effect on xanthine oxidase(XOD) and its inhibitory mechanism of total flavonoids from Hypericum Ascyron L.(HAF) were investigated through the testing of inhibition rate and inhibition kinetics.The antioxidant activities of the flavonoids were evaluated in vitro by scavenging capability of hydroxyl free radical,total reductive ability and total antioxidant capability.The result showed that the flavonoids were reversible and competitive inhibitor,and their inhibitory effect on XOD showed a dosage-dependent manner.The half inhibition concentration(IC50) and inhibition constant(Ki) were obtained to be 11.73 μg/mL and 0.61 μg/mL,respectively.The antioxidant assay indicated that total flavonoids from Hypericum Ascyron L.possessed a considerable hydroxyl radicals scavenging activity(IC50=0.135 mg/mL),evident total reductive ability and total antioxidant capacity,which should be further investigated and utilized as a potential antioxidant and protective drug of hyperuricemia or dietary function factors.
