银杏提取物缓解丙泊酚麻醉大鼠海马组织损伤的机制研究

Study on the Mechanism of Ginkgo Biloba Extract in Alleviating Hippocampal Tissue Injure of Anesthetized Rats by Propofol

目的:探究银杏提取物(GBE)对麻醉大鼠海马环腺苷酸反应元件结合蛋白-1(CREB1)、脑源性神经营养因子(BD-NF)表达的影响。方法:将大鼠随机分为正常对照组、模型组、银杏提取物低(GBE-L,40 mg·kg^-1)、中(GBE-M,60 mg·kg^-1)、高(GBE-H,80 mg·kg^-1)剂量组、盐酸多奈哌齐(donepezil,1.67 mg·kg^-1)组,模型组经腹腔注射100 mg·kg^-1丙泊酚麻醉,GBE各组和Donepezil组在麻醉前腹腔注射相应药物,正常对照组经腹腔注射生理盐水,麻醉结束后测定大鼠舒张压(DAP)、收缩压(SAP)、心率(HR);麻醉结束后第2天行水迷宫实验,大鼠断颈处死后,HE染色观察海马组织的变化,免疫印迹(WB)和免疫组化法检测CREB1、p-CREB1、BDNF、caspase-3、Bal-2蛋白表达。结果:与正常对照组相比,模型组SAP、DAP、逃避潜伏期、caspase-3蛋白表达均显著升高,穿越原平台次数、Bal-2、BDNF、p-CREB1蛋白以及蛋白阳性率表达均显著降低(P<0.05)。与模型组相比,GBE各剂量组及Donepezil组SAP、DAP、逃避潜伏期、caspase-3蛋白表达显著降低,穿越原平台次数、Bal-2、BDNF、p-CREB1蛋白以及蛋白阳性率表达显著升高(P<0.05)。正常对照组海马神经元细胞结构完整,形态正常,细胞紧密排列染色质分布均匀;模型组细胞形态不规则,排列紊乱,细胞膜破碎,细胞融合,界限模糊;经GBE干预后神经元细胞逐渐恢复正常。结论:GBE能够缓解麻醉药物对大鼠海马组织的损伤,可能与上调BDNF表达以及激活CREB1磷酸化有关。

Objective:To explore the influences of ginkgo biloba extract(GBE)on the expressions of cAMP response element binding protein-1(CREB1)and brain derived neurotrophic factor(BDNF)in the hippocampal tissue of anesthetized rats.Methods:The rats were randomly divided into the normal control group,the model group,GBE low(GBE-L,40 mg·kg^-1),medium(GBEM,60 mg·kg^-1)and high(GBE-H,80 mg·kg^-1)dose groups,and donepezil group(1.67 mg·kg^-1).The model group was anesthetized by intraperitoneal injection of 100 mg·kg^-1 propofol,GBE groups and donepezil group were given intraperitoneal injection of corresponding drug before anesthesia,and the normal control group was given intraperitoneal injection of normal saline.The diastolic blood pressure(DAP),systolic blood pressure(SAP)and heart rate(HR)were measured after anesthesia.The water maze test was performed on the second day after anesthesia.The rats were sacrified by breaking necks,and then HE staining was used to observe the changes of hippocampal tissues,and the expressions of CREB1,p-CREB1,BDNF,caspase-3 and Bal-2 were detected by Western blot(WB)and immunohistochemistry.Results:Compared with those in the blank control group,SAP,DAP,escape latency and caspase-3 protein expressions in the model group were increased,and the number of passing through the original platform,Bal-2,p-CREB1,BDNF protein and protein positive expression rate were all decreased(P<0.05).Compared with those in the model group,SAP,DAP,escape latency and caspase-3 protein expressions in all GBE groups and donepezil group were decreased,and the number of passing through the original platform,Bal-2,p-CREB1,BDNF protein and protein positive expression rate were all increased(P<0.05).The hippocampal neurons in the blank control group had complete structure,normal morphology and well-distributed chromatin,the cells in the model group had irregular morphology,disordered arrangement,broken cell membranes,cell fusion and blurred boundaries,and after GBE intervention,the neurons gradually returned to normal.Conclusion:GBE can alleviate the anesthetic injury of hippocampal tissue in rats,which may be related to the up-regulation of BDNF expression and the activation of CREB1 phosphorylation.