Abstract: Objective To investigate the protective effect of epigallocatechin-3-gallate( EGCG) on the substantia nigra dopaminergic neuron in Parkinson disease( PD ) rats induced by rotenone. Methods The healthy adult male 60 Wistar rats were randomly distributed to the following groups:control group,PD group and drug therapy group( n=20 each group),PD and drug therapy groups were injected subcutaneously rotenone in the back to prepare the PD rats model,the rats of drug therapy group were injected intraperitoneally EGCG at the same time. Spectrophotometry was used to detect oxidative stress parameters in rats( malondialdehyde and glutathione),immunocytochemistry and western blot were used to detect the expression of tyrosine hydroxylase( TH)in the substantia nigra and striatum of rats. Results Malondialdehyde(MDA)was significantly higher(P ﹤0. 05),and glutathione(GSH)was significantly decreased(P﹤0. 05)in the rats striatum of rotenone group than those of control group. The number of TH positive neurons in midbrain was significantly less than that of control group( P﹤0 . 05 ), but the expression of TH was significantly decreased in the substantia nigra and striatum compared with control group ( P ﹤ 0 . 05 );MDA obviously decreased and GSH increased significantly after the intervention of EGCG compared with that of rotenone group( P ﹤0. 05 ),the number of TH positive neurons significantly increased ( P ﹤ 0 . 05 ) and TH protein increased significantly ( P ﹤ 0 . 05 ). Conclusion Oxidative stress plays a very important role in the pathogenesis of PD,anti-oxidation treatment can effectively reduce the injury of dopaminergic neurons in the brain of rat,which provides a new target for the treatment of PD.

Key words: Parkinson disease, epigallocatechin-3-gallate, dopamine