ObjectiveTo explore the neuroprotective effect of ginsenoside Rg1 against PC12 cell apoptosis induced by 1-methyl-4-phenylpyridinum(MPP+). MethodsMPP+-induced apoptosis in PC12 cells, with the characteristics of dopaminergic neuron, were taken as the model of Parkinson disease in vitro. The cells were divided into control group, MPP+ group and 3 ginsenoside Rg1 pretreatment groups (concentrations 10, 20, and 50 μmol/L). MTT assay was used for detecting the cell viability, FCM for apoptosis ratio, TUNEL enzyme labelling for DNA fragment of the cell nuclear, and Western blotting analysis for cytochrome C protein.ResultsGinsenoside Rg1 (10, 20, and 50 μmol/L) showed protective effect against MPP+-induced PC12 cells injury. Compared with MPP+-treated cells(\[52±4.7\]%), pretreatment with 10, 20, and 50 μmol/L ginsenoside Rg1 increased the cell viability to (64±3.4)%, (72±5.2)% and (83±6.2)%, respectively (P<0.05 or P<0.01). FCM analysis indicated that apoptosis rates decreased by ginsenoside Rg1 pretreatment, with the apoptosis rates in the control, MPP+ and 3 ginsenoside Rg1 groups (10, 20, 50 μmol/L) being 1.8%, 44.5%, 32.9%, 21.1% and 14.2%, respectively. We also found that ginsenoside Rg1 pretreatment greatly decreased DNA fragment of PC12 cells. Western blotting analysis indicated that the cytochrome C was depressed by the ginsenoside Rg1 pretreatment. ConclusionGinsenoside Rg1 can protect PC12 cells against MPP+-induced apoptosis in a concentration-dependent manner, which may be closely related to down-regulation of cytochrome C over-expression in the mitochondria.