Abstract: Objective To investigate the protective effects of green tea polyphenols(GTPs)on dopamine neuron loss in substantia nigra concomitant with a depletion of dopamine in corpus striatum induced by the N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)in mice as a model of Parkinson disease.Methods Male C57BL/6 mice were intraperitoneally injected with saline + saline(group A),saline + GTPs(group B),saline+MPTP(group C)and GTP+MPTP(group D)at 2-hour intervals for a total of 3 doses for MPTP and 5 doses for GTPs(10 or 50 mg/kg delivered).The animals were sacrificed 7 d after the last injection.Levels of dopamine and its metabolites in the corpus striatum were measured with high-performance liquid chromatography with an electrochemical detector(HPLC-ECD).Results Level of dopamine and its metabolites in the corpus striatum in group C decreased significantly compared with group A or B;however,those in group D(both 10 and 50 mg/kg)prevented these effects.Conclusion GTPs can protect the dopamine neurons from loss in MPTP-induced mice.

Key words: green tea polyphenols(GTPs), Parkinson disease, dopamine, mice