Abstract: Total flavonoids of Chaenomeles speciosa (TFCS) were purified with macroporous resin from the 70% ethanol reflux extract,and its antioxidant activities were then assayed.The in vitro antioxidant results of TFCS showed that the efficacy on reducing power,hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) were 99.99%,97.8%,and 69.8%,respectively,and the efficacy on superoxide anion was merely 38.3%.The in vivo test showed that TFCS significantly increased the superoxide dismutase (SOD) activity,whereas an reduced level of malondialdehyde (MDA) products was obtained in lipopolysaccharide (LPS) induced oxidative stress mice model.Results suggested that TFCS displayed a strong antioxidant activity by direct scavenging of free radicals,increasing the main antioxidant enzyme SOD activity,but reduced the formation of lipid peroxidation MDA products.

Key words: Chaenomeles speciosa, flavonoids, antioxidant, in vitro and in vivo