Abstract: The aim of this study was to evaluate the in vitro and in vivo antioxidant activity of Olea europaea L.leaf extracts.The in vitro antioxidant activity was evaluated by DPPH· and ·OH scavenging assays,and the in vivo antioxidant activity was evaluated using subacute aging mice model.The subacute aging model mice were made by back subcutaneous injection of D-galactose every day.With VE as positive control,the mice were given by garage three different doses (58,116,232 mg/kg BW,respectively) of O.europaea leaf extracts,for 30 days,the malondialdehyde (MDA),superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) were determined,and the liver and brain tissue’s morphological changes were observed.The SOD and GSH-Px activities in aging model group were decreased,and MDA level was increased significantly as compared to normal mice (P<0.05).While in the O.europaea leaf extract treatment group,the activity of SOD and GSH-Px were increased and MDA level decreased significantly as compared to the model group (P<0.05). O.europaea leaf extracts improved the cell shape and the edema situation of D-gal induced aging mice’s liver,brain cortex and hippocampal neurons obviously.The IC₅₀ of O.europaea  leaf extracts scavenging DPPH· and ·OH were 0.064 mg/mL and 0.066 mg/mL respectively.The experimental results indicated that O.europaea leaf extracts had good antioxidant activity.

Key words: Olea europaea L.leaf extract, D-gal, antioxidation, mice