Abstract:The protective effect of different polar extracts of Moringa oleifera leaves on oxidative damage of HepG2 cells induced by H2O2and its antiproliferative effect on HepG2 cells and screen polar extracts with strong activity were investigated.HepG2 cells were induced by oxidative damage of 400 μmol/L H2O2.Cell survival rate was measured by methyl thiazolyl tetrazolium（MTT）assay，malondialdehyde（MDA）contents and glutathione peroxidase（GSH-Px），superoxide dismutase（SOD）and catalase（CAT）activities were measured by biochemical method.When the concentration of different polar extracts of Moringa oleifera leaves was lower than 1.0mg/mL，there was little effect on the cell survival rate.And it by reducing the contents of MDA and increasing the activities of SOD，GSH-Px and CAT，made all the indexes of oxidative damage cells tend to the level of normal cells，showed a strong protective effect of oxidative damage.The order of the protective effect was as follows：M2＞M3＞M＞M4，and it had concentration dependence.MTT results showed that all polar extracts had inhibitory effect on HepG2 cells with the dependence of concentration and time when the concentration was more than 1.0 mg/mL.The order of inhibitory effect was as follows：M2＞M3＞M＞M4，and the IC50value of M2 was 1.83 mg/mL after 72 hours.Under the concentration of 1.0 mg/mL，the different polar extracts of Moringa oleifera leaves could effectively protect HepG2 cells from oxidative damage caused by H2O2，but with the increase of the concentration and the prolongation of the action time，they all showed the inhibition of HepG2 cells proliferation.Among them，the antioxidant and antiproliferative activities of the ethyl acetate extract（M2）of Moringa oleifera leaves were the strongest.