银杏叶提取物对帕金森病模型大鼠多巴胺神经元的保护作用

The neuron-protective effect of ginkgo biloba extract on rat models of Parkinson's disease

目的探讨银杏叶提取物(EGb)对部分损毁的帕金森病(PD)模型大鼠多巴胺(DA)能神经元的保护作用及其可能机制。方法 65只健康雄性SD大鼠随机分为4组:对照组、PD组、银杏叶提取物(EGb)低剂量组(20mg/kg)和高剂量组(40mg/kg)。采用免疫组化法观察大鼠黑质酪氨酸羟化酶(TH)阳性细胞数目的变化,以及黑质区谷胱甘肽过氧化物酶(GSH-PX)、丙二醛(MDA)、超氧化物歧化酶(SOD)含量的变化。结果 PD模型组大鼠损毁侧黑质致密部(SNc)和腹侧被盖区(VTA)TH阳性细胞数目明显减少(均P<0.05);黑质内MDA含量升高(P<0.01),GSH-PX活力下降(P<0.05)。给予EGb后,随治疗剂量增加,SNc和VTA区DA神经元数目升高(P<0.05);黑质内MDA含量降低,GSH-PX活力增加,以高剂量组改变更为显著(P<0.01;P<0.05);4组之间SOD活力虽有不同,但差异不显著(P>0.05)。结论 EGb能够抑制脑黑质DA能神经元的数量减少,对PD模型大鼠DA能神经元具有保护作用。

Objective To explore the neuron-protective effect of ginkgo biloba extract(EGb) on partially-damaged rat Parkinson's disease(PD) models.Methods Sixty-five rats were randomly assigned into four groups: control group,PD group,low-(20 mg/kg) and high-(40 mg/kg) dose EGb groups.Quantitative immunohistochemistry was used to detect the number of neurons expressing hydroxylase(TH) in substantial nigra pars compacta(SNc),and contents of glutathione peroxidase(GSH-PX),maleic dialdehyde(MDA) and superoxide dismutase(SOD).Results Siginificantly decreased number of TH-positive cells in SNc and ventral tegmental area(VTA) appeared in PD group(P<0.05),accompanied with obviously increased MDA content(P<0.01) and decreased GSH-PX activity(P<0.05).EGb treatment increased the number of DA neurons in SN and VTA,reduced MDA content and promoted GSH-PX activity;the therapeutic effect of EGb was more significant in high-dose group(P<0.01 in high-dose group and P<0.05 in low-dose group),although SOD activity varied and no significant difference was found among the four groups.Conclusion EGb can provide dose-dependent protection on DA neurons by interrupting the oxidative-stress pathway of partially-damaged PD rat models.