安徽医科大学学报

目的 探究肉苁蓉总苷（GCs）对1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）诱导的帕金森病（PD）模型小鼠的神经保护作用及其可能机制。方法 将40只小鼠随机分为空白（Control）组、PD组、GCs组和左旋多巴（L-DOPA）组，每组10只。Control组腹腔注射给予生理盐水，其余各组腹腔注射MPTP(30 mg/kg),1次/d，连续5 d；造模结束后，Control组和PD组灌胃给予生理盐水，GCs组和L-DOPA组分别给予100 mg/kg和50 mg/kg剂量灌胃，1次/d，连续28 d。采用旷场实验和转棒实验评估运动功能；免疫组织化学法检测中脑黑质酪氨酸羟化酶（TH）阳性神经元数量；透射电镜观察黑质线粒体超微结构；生化法检测黑质组织中谷胱甘肽（GSH）、丙二醛（MDA）、总超氧化物歧化酶（T-SOD）及活性氧（ROS）水平；Western blot法检测黑质组织中TH、核因子E2相关因子2(Nrf2)、Kelch样ECH相关蛋白1(Keap-1)及血红素加氧酶1(HO-1)的蛋白表达情况。结果 与Control组相比，PD组小鼠运动功能下降（P<0.01），黑质T-SOD活性降低（P<0.01）,TH阳性神经元数量、GSH含量减少（P<0.01）,MDA、ROS含量增多（P<0.01）；与PD组相比，GCs组小鼠运动功能改善（P<0.05）,T-SOD活性升高（P<0.05），黑质TH阳性神经元数量、GSH含量增多（P<0.05）,MDA、ROS含量减少（P<0.05）。Control组黑质线粒体形态结构正常，未见明显膜结构模糊及空泡样改变；PD组线粒体肿胀、嵴结构紊乱及空泡样改变；GCs组线粒体肿胀、嵴结构紊乱及空泡样改变有所减轻。与Control组相比，PD组TH、Nrf2和HO-1蛋白水平均下降（P<0.01）,Keap-1蛋白水平上调（P<0.01）；与PD组相比，GCs组TH、Nrf2和HO-1蛋白水平均上调（P<0.05）,Keap-1蛋白水平下降（P<0.05）。结论 GCs可改善MPTP诱导的PD模型小鼠运动功能障碍，减轻多巴胺能神经元及线粒体损伤，其作用可能与调节Nrf2/HO-1信号通路相关蛋白表达、增强抗氧化能力及减轻氧化应激有关。

Objective To investigate the neuroprotective effect of glycosides of cistanches(GCs) in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson's disease(PD) model mice and its potential mechanism.Methods Forty mice were randomly divided into control group, PD group, GCs group and levodopa(L-DOPA) group, with 10 mice in each group. The control group received intraperitoneal injection of normal sa‑line, while the other groups were intraperitoneally injected with MPTP(30 mg/kg) once daily for 5 consecutive days. After model establishment, the control group and PD group were intragastrically administered normal saline, and the GCs group and L-DOPA group received intragastric administration once daily for 28 consecutive days, at doses of 100 mg/kg and 50 mg/kg, respectively. The open field test and rotarod test were used to evaluate motor function. Immunohistochemistry was performed to detect the number of tyrosine hydroxylase(TH)-positive neurons in the substantia nigra of the midbrain. Transmission electron microscopy was adopted to observe the ultrastructure of mitochondria in the substantia nigra. Biochemical assays were used to determine the levels of glutathione(GSH), malondialdehyde(MDA), total superoxide dismutase(T-SOD) and reactive oxygen species(ROS) in substantia nigra tissues. Western blot was applied to detect the protein expression of TH, nuclear factor erythroid 2-related factor 2(Nrf2), Kelch-like ECH-associated protein 1(Keap-1) and heme oxygenase-1(HO-1) in substan‑tia nigra tissues.Results Compared with the control group, mice in the PD group exhibited markedly impaired mo‑tor function, significantly decreased T-SOD activity, obvious reductions in the number of TH-positive neurons and GSH content, as well as elevated MDA and ROS levels in the substantia nigra(P<0. 01). Compared with the PD group, mice in the GCs group showed improved motor function, increased T-SOD activity, higher number of THpositive neurons and elevated GSH content, accompanied by decreased MDA and ROS levels(P<0. 05). In the control group, mitochondria in the substantia nigra displayed normal morphology without obvious blurred mem‑brane structures or vacuolar degeneration. The PD group presented mitochondrial swelling, disordered cristae and vacuolar changes, whereas these mitochondrial pathological alterations were alleviated in the GCs group. Com‑pared with the control group, the protein levels of TH, Nrf2 and HO-1 were significantly downregulated, while Keap-1 protein expression was markedly upregulated in the PD group(P<0. 01). Compared with the PD group, the GCs group showed significant upregulation of TH, Nrf2 and HO-1 protein levels and a notable reduction in Keap-1 protein level(P<0. 05).Conclusion GCs ameliorate motor dysfunction and attenuate dopaminergic neu‑ronal and mitochondrial damage in MPTP-induced PD model mice. These effects may be associated with modula‑tion of Nrf2/HO-1 pathway-related protein expression, enhancement of antioxidant capacity, and alleviation of oxi‑dative stress.