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(20 mg/kg)和高剂量组(40 mg/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.
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