人参皂苷Rg1拮抗MPTP诱导小鼠黑质中铁增高的作用

目的研究人参皂苷Rg1(ginsenoside Rg1,Rg1)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methy-4-phenyl-1,2,3,6-tetrahydropyridine,MPTP)致帕金森病(Parkinson’s disease,PD)小鼠黑质多巴胺(dopamine,DA)能神经元变性的保护作用及其可能机制。方法 C57BL6小鼠随机分为正常对照组(NS,i.p.)、MPTP组(30 mg/kg×5 d,i.p.)及Rg1(5 mg/kg×8 d,i.p.)预处理组。应用免疫组织化学法、Perls’铁染色、逆转录-聚合酶链式反应(RT-PCR)以及图像分析等技术观察黑质内多巴胺转运蛋白(dopamine transporter,DAT)免疫反应活性变化、铁染色阳性细胞数的变化和DAT mRNA的表达水平的变化,用高效液相色谱法(HPLC)检测小鼠纹状体内DA及其代谢物二羟基苯乙酸(dihydroxyphenylacetic acid,DOPAC)和高香草酸(homovanillic acid,HVA)含量。结果与正常对照组相比,MPTP组黑质内铁染色阳性细胞数增高以及纹状体内DA及其代谢产物DOPAC和HVA的含量明显减少;与MPTP组相比,Rg1预处理组黑质内铁染色阳性细胞数降低以及纹状体内DA及其代谢产物DOPAC和HVA的含量明显增加(P<0.01)。与正常对照组相比,MPTP组黑质内DAT免疫反应活性和DAT mRNA的表达明显降低(P<0.01);与MPTP组相比,Rg1预处理组黑质内DAT免疫反应活性和DAT mRNA的表达有所增高(P<0.05)。结论 Rg1对MPTP致PD小鼠黑质DA能神经元的损伤具有一定的保护作用,其机制可能与Rg1能通过降低MPTP诱导的铁过多聚积从而拮抗氧化应激反应有关。

The role of ginsenoside Rg1 in antagonism of MPTP-induced iron accumulation in substantia nigra of mice

Objective To investigate the effect of ginsenoside Rg1 on the degeneration of dopaminergic neurons in the substantia nigra in 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP) treated C57BL6 mice.Methods Mice were randomly divided into three groups:normal group,MPTP group and Rg1 pretreatment group.The mice were injected intraperitoneally with normal saline in normal group,30 mg/kg MPTP for 5 d in MPTP group,and 5 mg/kg Rg1 for 8 d and 30 mg/kg MPTP for 5 d in Rg1 pretreatment group,respectively.RT-PCR,immu...