柴胡皂苷A减轻脑缺血再灌注大鼠海马神经元损伤

Saikosaponin A attenuates hippocampal neuron damage in rats with cerebral ischemia-reperfusion

目的探讨柴胡皂苷A(Saikosaponin A,SA)通过上调SIRT1水平减轻脑缺血再灌注(ischemia reperfusion,I/R)大鼠海马神经元损伤的作用。方法大鼠随机分为6组,每组9只,分别为假手术组(Sham)、模型组(I/R)、柴胡皂苷A 1 mg/kg组(I/R+SA 1 mg/kg)、柴胡皂苷A 5 mg/kg组(I/R+SA 5 mg/kg)、柴胡皂苷A 10 mg/kg(I/R+SA 10 mg/kg)和尼莫地平1 mg/kg组(I/R+NMDP 1 mg/kg)。双侧颈总动脉用微动脉夹夹闭法构建脑缺血再灌注模型,灌胃给药7 d。记录各组大鼠跳台实验犯错次数和Y迷宫实验检测新异臂进入次数,HE染色观察脑组织病理损伤,采用2,3,5-三苯基氯化四氮唑法计算各组大鼠脑梗死率、脑组织含水量及脑指数,尼氏小体染色检测神经元凋亡,免疫印迹法检测Caspase3,Caspase9,Bax/Bcl-2和SIRT1的表达,试剂盒检测SOD、MDA、LDH的含量,RT-PCR检测SIRT1的表达。结果柴胡皂苷A能减少大鼠跳台实验犯错次数,增加新异臂进入次数,减少脑梗死率、脑组织含水量及脑指数,降低Bax/Bcl-2和Cleaved caspase3/caspase3、Cleaved caspase9/caspase9的比值,降低MDA和LDH的含量,升高SOD活性,上调SIRT1表达水平(P<0.05)。结论胡皂苷A能缓解缺血再灌注大鼠海马神经元损伤和氧化应激,这与SIRT1上调有关。

Objective To investigate the role of saikosaponin A(SA)in reducing hippocampal neuron damage in ischemia reperfusion(I/R)rats by up-regulating SIRT1 levels.Methods Rats were randomly divided into 6 groups:a sham operation group(Sham),a model(I/R)group,an I/R+SA 1mg/kg group,an I/R+SA 5mg/kg group,an I/R+SA 10mg/kg group and an I/R+NMDP 1mg/kg group,9 rats in each group.The cerebral ischemia-reperfusion model was constructed by the bilateral common carotid artery(CCA)with arterial clip clamping method,and it was administered intragastically for 7 days.The number of mistakes made by the jumping test and the number of new maze tests in the Y-maze test were recorded in each group of rats.Pathological damage of brain tissue was observed by HE staining.The 2,3,5-triphenyltetrazolium chloride method was used to calculate the cerebral infarction rate,brain tissue water content and brain index of each group of rats.Neuronal apoptosis was detected by Nissl body staining.The expression of Caspase3,Caspase9,Bax/Bcl-2 and SIRT1 was detected by Western blotting.The contents of superoxide dismutase(SOD),malondialdehyde(MDA),and lactate dehydrogenase(LDH)were detected by the kit.The expression of SIRT1 was detected by RT-PCR.Results Saikosaponin A reduced the number of mistakes in the platform-jumping experiment in rats,increased the number of new arms entering,reduced cerebral infarction rate,brain tissue water content,and brain index,and reduced Bax/Bcl-2,the ratio of Cleaved caspase3 and caspase3,Cleaved caspase9 and caspase9,decreased the content of MDA and LDH,increased the activity of SOD,and increased the expression level of SIRT1(P<0.05).Conclusions Saikosaponin A alleviates hippocampal neuronal injury and oxidative stress in ischemia-reperfusion rats,which is related to the up-regulation of SIRT1.