人参皂苷Rg1对1-甲基-4-苯基吡啶离子诱导的PC12细胞凋亡的保护作用

Neuroprotective effects of ginsenoside Rg1 on 1-methyl-4-phenylpyridinum-induced apoptosis in PC12 cells

目的探讨人参皂苷Rg1对1-甲基-4-苯基吡啶离子(1-methyl-4-phenylpyridinum,MPP+)诱导的PC12细胞凋亡是否具有保护作用。方法采用MPP+诱导的具有多巴胺能神经元特性的PC12细胞凋亡作为帕金森病(Parkinson disease,PD)的体外模型。实验分正常对照组、MPP+损伤组、人参皂苷Rg1(10、20、50μmol/L)3个浓度预处理组。用MTT法测定细胞活性,流式细胞术检测细胞凋亡,TUNEL法检测细胞凋亡断裂的DNA片段,蛋白质印迹法分析细胞色素C(cytochrome C,Cyt C)蛋白含量。结果 10、20、50μmol/L人参皂苷Rg1对MPP+诱导的PC12细胞具有一定的保护作用。与MPP+损伤组[(52±4.7)%]相比,10、20、50μmol/L人参皂苷Rg1预处理细胞活力分别上升为(64±3.4)%、(72±5.2)%、(83±6.2)%(P<0.05或P<0.01)。经流式细胞术检测,正常组、MPP+损伤组、人参皂苷Rg1预处理组(10、20、50μmol/L)细胞凋亡率分别为1.8%、44.5%、32.9%、21.1%和14.2%。人参皂苷Rg1预处理后,细胞断裂的DNA片段明显减少。另外,蛋白质印迹分析也显示人参皂苷Rg1可抑制MPP+诱导的Cyt C的过表达。结论人参皂苷Rg1对MPP+诱导的细胞凋亡具有浓度依赖性的保护作用,其保护机制可能与下调线粒体内Cyt C的过表达有关。

Objective To explore the neuroprotective effect of ginsenoside Rg1 against PC12 cell apoptosis induced by 1-methyl-4-phenylpyridinum（MPP＋）.Methods MPP＋-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.Results Ginsenoside 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（P0.05 or P0.01）.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.Conclusion Ginsenoside 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.