Neuroprotective Effects of Ginsenoside Rg_1 on the Dopaminergic Neurons in the Substantia Nigrain Mptp-Treated C_(57)BL_6 Mice

Aim To investigate whether ginsenoside Rg1 can prevent the degeneration of dopaminergic neurons in the substantia nigra (SN) in 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated C57BL6 mice.Method Mice were randomly divided into three groups: control group (NS, ip), MPTP group (30mg·kg-1×5d,ip) and Rg1 (5mg·kg-1×8d,ip) pretreatment group. Using RT-PCR, tyrosine hydroxylase (TH) immunohistochemistry and HPLC,the degeneration of dopaminergic neurons was measured in the SN of MPTP treated mice and assessed the effects of treatment with ginsenoside Rg1.Results The number of TH-immunoreactive cells in the SN of MPTP treated mice, as well as the contents of dopamine and its metabolites in the striatum, decreased significantly. Treatment with ginsenoside Rg1 reversed these effects(P0.01). The expression of Bcl-2 and TH mRNA in the SN also decreased significantly in MPTP treated mice (P0.01), while the expression of Caspase-3 and Bax mRNA increased significantly(P0.01). Treatment with ginsenoside Rg1 reversed the above changes(P0.05).Conclusion Ginsenoside Rg1 is neuroprotective against the neurotoxin MPTP,possibly due to its anti-apoptosis activity.