Protective effect and mechanism of Ginkgo biloba leaf extracts for Parkinson disease induced by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine

AIM: To observe the effects of extracts of Ginkgo biloba leaves (EGb) on the Parkinson disease (PD) models induced by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) and its ion 1-methyl-4-phenylpyridinium, (MPP+). METHODS: MPTP was microinjected into substantia nigra of rats to induce a behavior change of rotation. EGb (ip, 50 or 100 mg(.)kg(-1.)d(-1)) was pretreated consecutively for 19 d before MPTP administered and 1 d after MPTP administered. The contents of malondialdehyde (MDA), superoxide dismutase (SOD), and dopamine (DA) in substantia nigra of model rats were determined. Apoptosis of PC12 cells was induced by MPP+, and the protective effect of EGb (25, 50, and 100 mg/L) was also observed. The cells of apoptosis were observed under a microscope and counted under a fluoroscope after stained with AO/EB. RESULTS: EGb (100 mg(.)kg(-1.)d(-1)) decreased the duration and frequency of the rotation of rats (P < 0.05, n = 10) while EGb (50 or 100 mg/L) inhibited the decreases of DA and SOD and the increase of MDA induced by MPTP, ( P < 0.05 or P < 0.01, n = 10). MPP+ (10 mu mol/L) induced the apoptosis of PC12 cells, and EGb (50 or 100 mg/L) prevented cells from apoptosis at 6 h, 12 h, and 24 h ( P < 0.05 or P < 0.01, n = 3). CONCLUSION: EGb possesses protective effect on the PD models in vivo and in vitro. The anti-oxidation and anti-apoptosis may be one of the mechanisms underlying the neuroprotective effect of EGb.