Flavonoids from : extraction and mechanism, antioxidant capacity and effects on CAT and GSH-Px of .

is a famous medicinal plant in China, Southeast Asian and some other regions. Flavonoids are regarded as its supremely important active constituents used in phytomedicines and/or functional foods. It is of theoretical and applied significance to optimize the procedure for extraction of flavonoids with high bioactivity from , to unveil extraction mechanism, to identify chemical composition of flavonoids, to analyze free radical-scavenging ability of flavonoids, and to investigate their effects on the model organism .Box-Behnken design was applied to optimization of extraction procedure. Laser diffraction particle size analysis was used to clarify extraction mechanism. Chemical composition of flavonoids was analyzed using high-performance liquid chromatography. Antiradical capacities of flavonoids were determined by chemical-based assay. Then, effects of flavonoids on catalase (CAT) and glutathione peroxidase (GSH-Px) in were investigated for the first time.The optimal condition for ultrasonic extraction of antioxidant flavonoids from was achieved and extraction mechanism was discussed. flavonoids contained icariin, epimedin A, epimedin B and epimedin C. flavonoids exhibited the ability to scavenge ABTS and DPPH radicals with EC values of 55.8 and 52.1 µg/ml, respectively. Moreover, flavonoids were able to increase activities of CAT and GSH-Px in . For females, oral administration of flavonoids improved CAT and GSH-Px activities by 13.58% and 5.18%, respectively. For males, oral administration of flavonoids increased CAT and GSH-Px activities by 13.90% and 5.65%, respectively.Flavonoids ultrasonically extracted from considerably affected antioxidant defense system in . Flavonoids of showed great potential for becoming a natural antioxidant because of their antiradical ability and effects on CAT and GSH-Px of the model organism.