马钱苷对小鼠脑缺血再灌注损伤保护作用的实验研究

Research on Protective Effect of Loganin on Acute Cerebral Ischemic-Reperfusion Injury in Mice

目的:探讨马钱苷对脑缺血再灌注损伤(CIRI)小鼠神经元凋亡的保护作用及机制。方法:将ICR小鼠随机分为假手术组、模型组、依达拉奉(5 mg/kg)组、马钱苷(5、10、15 mg/kg)组,线栓法建立小鼠大脑中动脉栓塞(MCAO)模型,缺血1 h后,各组立即腹腔注射给药,再灌注24 h;观察各组小鼠神经功能评分、脑梗死体积、脑含水量、脑指数及脑组织结构病理变化;TUNEL法检测脑缺血区细胞凋亡水平;免疫组化法检测脑缺血区Caspase-3蛋白表达水平;透射电镜观察缺血区大脑皮层病理结构变化。结果:与模型组相比,马钱苷各剂量组均能不同程度降低CIRI小鼠神经功能评分、脑梗死体积、脑含水量及脑指数(P<0.05,P<0.01),改善脑缺血区病理结构变化。马钱苷10、15 mg/kg组能显著减少神经元细胞凋亡数量(P<0.05,P<0.01),下调Caspase-3蛋白表达量(P<0.05,P<0.01),缺血区大脑皮层中线粒体水肿情况明显减少,内质网结构损伤得到明显改善。结论:马钱苷对小鼠脑缺血再灌注损伤具有保护作用,能减少神经元的凋亡,其作用机制可能与减轻线粒体和内质网损伤、下调Caspase-3蛋白有关。

Objective:To observe the protective effect of Loganin on neuronal apoptosis in mice with acute cerebral ischemia-reperfusion injury(CIRI)and explore the mechanism.Methods:The ICR mice were randomly divided into sham group,model group,Edaravone(5 mg/kg)group and Loganin(5,10,15 mg/kg)groups.The Model of middle cerebral artery occlusion(MCAO)was established by thread occlusion,after 1 hour of ischemia,each group was injected intraperitoneally and reperfusion for 24 hours.To observe the neurological function score,cerebral infarction volume,content of brain water,brain index and the common changes of brain pathological structure;The level of neuronal apoptosis in cerebral ischemic area was detected by TUNEL method;the expression level of Caspase-3 protein was detected by immunohistochemical method.The ultra microstructure changes of cerebral cortex in mice were observed under electron microscope.Results:Compared with model group,the Loganin groups could decreased the nerve function score,the volume of brain infarct,the content of brain water,brain index and the volume of ischemia in mice with different degrees in CIRI mice(P<0.05,P<0.01),and improve the pathological changes of cerebral ischemic area.Loganin 10 and 15 mg/kg could significantly reduce the number of neuronal apoptosis and down-regulate the expression of Caspase-3 protein(P<0.05,P<0.01).The mitochondrial edema in the cerebral cortex of ischemic area in Loganin 10 and 15 mg/kg groups was significantly reduced and the damage of endoplasmic reticulum structure was significantly improved.Conclusion:Loganin has a protective effect on CIRI mice and can reduce neuronal apoptosis.The mechanism may be related to reduction of mitochondrial and endoplasmic reticulum injury,the down-regulation of Caspase-3 protein.