人参皂甙Rg1对帕金森病小鼠黑质JNK细胞凋亡通路的影响

目的 探讨人参皂甙Rg1(ginsenoside Rg1)抗帕金森病(PD)小鼠黑质神经元凋亡的可能机制。方法 采用MPTP制备帕金森病(PD)小鼠模型，经人参皂甙Rgl预处理后，用尼氏染色、TH和活化型caspase-3组织化学染色及TUNEL染色法观察黑质神经元的损害情况，并计算神经元的凋亡率，同时应用蛋白免疫印迹法检测黑质神经元磷酸化．JNK(c—Jun氨基末端激酶)及磷酸化c—Jun蛋白表达水平。结果 人参皂甙Rg1预处理可减轻PD小鼠黑质致密带Niss1阳性神经元和TH阳性神经元的丢失现象，同时减少磷酸化．INK及磷酸化C-Jun蛋白表达水平，活化型caspase-3表达减少，降低黑质神经元的凋亡率。结论人参皂甙Rg1能减少MPTP诱导的小鼠黑质神经元凋亡，其机制与阻断．JNK细胞凋亡通路激活有关。

THE INFLUENCE OF GINSENOSIDE Rg1 ON JNK SIGNALING CASCADE IN PD MOUSE SUBSTANTIA NIGRA NEURONS

Objective To explore the possible molecular mechanism of Ginsenoside Rg1 preventing against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced substantia nigra neurons apoptosis in Parkinson disease(PD) mouse model. Methods C57BL mice were administrated(sc) with MPTP to produce PD mouse model.Different doses of Rg1(5.0,10.0,20.0*!mg/kg) were given(ip) prior 3*!d to MPTP in the pretreatment groups.Nissl staining,tyrosinehydroxythase(TH) immunostatining,cleaved caspase-3 immunostatining and TUNEL staining were used to observe the changes of nigra neurons,meanwhile,Western blot was used to detect the phosphorylated protein of JNK and c-Jun in substantia nigra. Results Pretreatment with Rg1 could prevent the loss of Nissl staining neurons and TH-positive neurons,inhibit JNK and c-Jun phosphorylation in SN,decrease the percent of cleaved caspase-3 and TUNEL-positive cell.Conclusion Rg1 can attenuate MPTP-induced apoptosis in substantia nigra neurons through blocking JNK signaling cascade.