[Possible Mechanisms of the Protective Effect of Ginsenoside Rg1 on Apoptosis in Substantia Nigra Neurons]

Aim: To investigate the role of ginsenoside Rg1 in preventing against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced apoptosis of the substantia nigra neurons in the mouse model of Parkinson's disease (PD).

Methods: C57B1 male mice were given MPTP i.p. in the PD model group. Different doses of ginsenoside Rg1 (2.5, 5.0 and 10.0 mg.kg-1) were given i.p. 3 days prior to MPTP in the pretreatment group. Nissl staining, tyrosine hydroxylase (TH) immunostaining and TdT-mediated duTP nick-end labeling (TUNEL) staining were used to observe the damage of nigral neurons. The method of immunostaining was used to detect the caspase-3 activity, expression of inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS).

Results: Pretreatment with ginsenoside Rg1 was shown to prevent the loss of Nissl staining neurons and TH-positive neurons, and decrease the percent of TUNEL-positive. Simultaneously, Rg1 was found to reduce caspase-3 activity and the expression of iNOS.

Conclusion: Ginsenoside Rg1 showed protective effect on MPTP-induced apoptosis in the mouse nigral neurons and this effect may be attributable to reducing the expression of iNOS and inhibiting the activation of caspase-3.