Antioxidant Activity of the Flavonoids of Gynura in Vitro and in Vivo

The total flavonoids in Gynura were extracted in volume fraction 80% alcohol and purified,and their antioxidant activity in vitro and in vivo was studied.After removing impurities,the crude extracts were purified with type AB-8 macroporous adsorption resin.The content of the total flavonoids was determined by spectrophotometry.The antioxidant activity of the total flavonoids in vitro was analyzed by using different assays with Vc as cross reference,for example,DPPH radical(DPPH·) scavenging assay,hydroxyl radical(·OH) scavenging assay,superoxide radical(O2-·) scavenging assay.The antioxidant activity of the purified flavonoids in vivo was also investigated.The content of total crude flavonoids from Gynura was 13.928 mg/g,and the purification ratio was 32.79%.The radical scavenging effect was enhanced with increasing flavonoid concentration.The scavenging effect of the purified flavonoids was greater than the crude extracts.The level of superoxide dismutase(SOD) activity in the brain and liver of mice was significantly higher in low doses groups than in normal control groups(p0.05),so was the level of catalase(CAT) activity in liver.The brain malondialdehyde(MDA) content was obviously lower than that of the normal control groups(p0.05).