Objectives: To observe the effect of electroacupuncture (EA) on behavior, oxidative stress factors in colon and substantia nigra of Parkinson's disease (PD) mice, so as to explore the mechanism of EA in treating PD.
Methods: C57BL/6 mice were randomly divided into blank, model and EA groups, with 12 mice in each group. The PD mouse model was established by continuous gavage of rotenone for 4 weeks. Mice in the EA group received EA (2 Hz/15 Hz) at "Baihui" (GV20), "Quchi" (LI11) and "Zusanli" (ST36) for 20 min, 5 days a week for 2 weeks. After intervention, gait analysis was used to evaluate the motor ability and motor coordination. Ink propulsion rate was used to evaluate the intestinal transport function. The level of reactive oxygen species (ROS) in the colon was detected by flow cytometry. The contents of total protein (TP), malondialdehyde (MDA) and activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) in colon and substantia nigra were detected by ELISA. The expression of nuclear factor E2-related factor 2 (Nrf2) in substantia nigra was detected by immunofluorescence staining.
Results: Compared with the blank group, the average speed, step rate, normal step ratio, distance between the front and hind feet, stride length, swing speed and maximum intensity of the maximum contact area of mice in the model group were decreased (P<0.000 1, P<0.01, P<0.001), the maximum change rate of gait was increased (P<0.001) in the model group. The intestinal propulsion rate, the activities of GSH-Px and SOD in the colon and substantia nigra, and the positive expression of Nrf2 in substantia nigra were decreased (P<0.000 1, P<0.01, P<0.05), while the fluorescence intensity of ROS in the colon, the contents of MDA in colon and substantia nigra were increased (P<0.01). Compared with the model group, the average speed, step rate, normal step ratio, distance between the front and hind feet, stride length, swing speed, and maximum intensity of the maximum contact area of the mice in the EA group were increased (P<0.01, P<0.05, P<0.001, P<0.000 1), the maximum change rate of gait was decreased (P<0.01). The intestinal propulsion rate, the activities of GSH-Px and SOD in the colon and substantia nigra, the positive expression of Nrf2 in substantia nigra were increased (P<0.001, P<0.05, P<0.000 1), while the ROS fluorescence intensity in the colon, the MDA contents in the colon and substantia nigra were decreased (P<0.01).
Conclusions: EA can improve the movement disorder, gait disorder and intestinal motor function of PD mice, and protect dopaminergic neurons from damage, which may be related to its effect in antagonistic brain-gut oxidative stress.
目的: 观察电针干预对帕金森病（PD）模型小鼠行为学、结肠及中脑黑质氧化应激因子的影响，探讨电针治疗帕金森病的作用机制。方法: 将C57BL/6小鼠随机分为空白组、模型组及电针组，每组12只。采用鱼藤酮连续灌胃4周构建PD小鼠模型。电针组于造模成功后电针刺激“百会”“曲池”“足三里”，20 min/次，1次/d，针刺5 d，休息2 d，共针刺14次。干预结束后采用步态分析实验评估各组小鼠运动能力及运动协调性；肠道推进率评估各组小鼠肠道传输功能；流式细胞术检测小鼠结肠活性氧（ROS）水平；ELISA法检测各组小鼠结肠及中脑黑质中总蛋白（TP）、丙二醛（MDA）含量和谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）活性；免疫荧光染色法检测小鼠中脑黑质中核因子E2相关因子2（Nrf2）蛋白的阳性表达。结果: 与空白组比较，模型组小鼠平均速度、步率、正常步序比、足间距、步幅长度、摆动速度、最大接触面积的最大强度降低（P<0.000 1，P<0.01，P<0.001），步态最大变化率升高（P<0.001），肠道推进率降低（P<0.000 1），结肠中ROS荧光强度升高（P<0.01），结肠及中脑黑质中GSH-Px、SOD活性降低（P<0.01，P<0.05），MDA含量升高（P<0.01），中脑黑质中Nrf2阳性表达降低（P<0.000 1）。与模型组比较，电针组小鼠平均速度、步率、正常步序比、足间距、步幅长度、摆动速度、最大接触面积的最大强度升高（P<0.01，P<0.05，P<0.001，P<0.000 1），步态最大变化率降低（P<0.01），肠道推进率升高（P<0.001），结肠中ROS荧光强度降低（P<0.01），结肠及中脑黑质中GSH-Px、SOD活性升高（P<0.05），MDA含量降低（P<0.01），中脑黑质中Nrf2阳性表达升高（P<0.000 1）。结论: 电针可改善PD模型小鼠的运动障碍、步态紊乱及肠道运动功能，保护多巴胺能神经元免受损害，其机制可能与电针可拮抗脑肠氧化应激有关。.
Keywords: Brain-gut axis; Dopaminergic neurons; Electroacupuncture; Oxidative stress; Parkinson’s disease.