女贞子提取物对帕金森病大鼠的神经炎症及AMPK/ERK信号通路的影响

Effects of Ligustrum lucidum extract on neuroinflammation and AMPK/ERK signaling pathway in rats with Parkinson’s disease

目的:探讨女贞子提取物(LLE)对帕金森病(PD)大鼠神经炎症以及腺苷酸激活蛋白激酶(AMPK)/细胞外调节蛋白激酶(ERK)信号通路的影响。方法:通过注射6-羟基多巴胺(6-OHDA)构建PD大鼠模型,将建模成功的大鼠随机分为模型组、LLE低、中、高剂量组、阳性对照组,每组15只;另取15只正常大鼠作为对照组;LLE低、中、高剂量组分别给予0.2 g/kg、0.4 g/kg、0.8 g/kg LLE灌胃,阳性对照组给予1.67 mg/kg美多芭灌胃,对照组、模型组大鼠灌胃等体积生理盐水,每天1次,连续15d。干预结束后,利用旋转试验检测大鼠行为学变化;利用酶联免疫吸附(ELISA)法测定大鼠脑组织中氧化应激指标[丙二醛(MDA)、还原型谷胱甘肽(GSH)、超氧化物歧化酶(SOD)],炎症因子[肿瘤坏死因子α(TNF-α)、一氧化氮(NO)]水平;采用免疫组化法检测多巴胺标志物酪氨酸羟化酶(TH)阳性细胞数;采用蛋白免疫印迹(western blotting)法检测PD大鼠脑组织中AMPK、ERK、p-AMPK、p-ERK表达。结果:与对照组相比,模型组大鼠旋转圈数及脑组织MDA、TNF-α、NO含量均增加(P<0.05),TH阳性细胞数,GSH、SOD水平及p-AMPK/AMPK、p-ERK/ERK比值均降低(P<0.05);与模型组相比,LLE随着剂量增加,大鼠旋转圈数、MDA、TNF-α、NO水平降低(P<0.05),TH阳性细胞数,GSH、SOD水平及p-AMPK/AMPK、p-ERK/ERK比值升高(P<0.05);LLE高剂量组各项指标与阳性对照组比较差异无统计学意义(P>0.05)。结论:LLE可以抑制PD大鼠氧化应激损伤,缓解大鼠炎性反应,其机制可能与激活AMPK/ERK信号通路有关。

Objective:To investigate the effects of Ligustrum lucidum extract(LLE) on nerve inflammation and adenosine monophosphate-activated protein kinase(AMPK)/extracellular signal-regulated kinase(ERK) signaling pathway in rats with Parkinson’s disease(PD).Methods:The rat model of PD was established by injection of 6-hydroxydopamine(6-OHDA).The PD rats were randomly divided into model group,positive control group,and low-,middle-and high-dose LLE group,with 15 rats in each group.Another 15 normal rats were selected as control group.The rats in the low,middle and high dose group of LLE were given 0.2 g/kg,0.4 g/kg and 0.8 g/kg LLE respectively,the positive control group was administered intragastrically 1.67 mg/kg Madopar,and the rats in the control group and model group were given the same volume of normal saline once a day for 15 days.After intervention,the behavioral changes of rats were detected by rotation test.The levels of oxidative stress indexesmalondialdehyde(MDA),reduced glutathione(GSH),superoxide dismutase(SOD),inflammatory factor-tumor necrosis factor(TNF-ɑ) and nitric oxide(NO) in rat brain tissue were measured by ELISA.The number of positive cells of dopamine marker-tyrosine hydroxylase(TH) was detected by immunohistochemistry,and the expression of AMPK,ERK,p-AMPK and pERK in the brain tissue of PD rats was detected by western blotting.Results:Compared with the control group,the number of rotation circles,MDA,TNF-ɑ and NO in the model group increased,while the number of TH positive cells,the levels of GSH,SOD and the rates of p-AMPK/AMPK and p-ERK/ERK decreased in the model group(P<0.05).Compared with the model group,with the increase of LLE dose,the number of rotation circles,the levels of MDA,TNF-ɑ and NO decreased,while the number of TH positive cells,GSH and SOD levels as well as the p-AMPK/AMPK and p-ERK/ERK rates increased(P<0.05).There was no significant difference between the high dose LLE group and the positive control group(P>0.05).Conclusion:LLE can inhibit oxidative stress and inflammatory response in PD rats,and the mechanisms may be related to the activation of AMPK/ERK signaling pathway.