乌灵菌粉水提物对MCAO小鼠海马结构及BDNF,GABA水平的影响

摘要

目的:探讨鸟灵菌粉(xylaria nigripes,XN)水提物对脑缺血再灌注模型小鼠海马形态和高分子量神经丝蛋白(neurofilament high molecular weight,NF-H)表达以及脑源性神经营养因子(brain derived neurotrophic factor,BDNF)和γ氨基丁酸(γ-arninobutyric acid,GABA)的影响.方法:将32只昆明小鼠随机分为对照组(sham)、模型组(MCAO)和乌灵菌粉水提物低、高剂量组,即XN(L)和XN(H).sham组进行假手术(皮肤切开,分离颈动脉),模型组(MCAO)及乌灵菌粉组进行大脑中动脉闭塞(middle cerebral artery occlusion,MCAO),sham组和MCAO组术后即刻腹腔注射生理盐水,乌灵菌粉组则注射不同剂量的乌灵菌粉水提物(0.3 g/kg和0.6 g/kg),术后24 h,通过尼氏染色、免疫组化染色和酶联免疫吸附实验(enzyme-linked immunosorbent assay,Elisa)分别观察海马结构和NF-H的表达情况以及BDNF和GABA水平.结果:(1)模型组小鼠海马出现大量的空洞样改变,细胞排列不整齐,XN(H)组空洞样改变减少;(2)模型组NF-H染色的积分光密度显著低于对照组和XN(H)组,差异具有统计学意义(P＜0.05);(3)Elisa检测显示,模型组海马BDNF和GABA水平显著低于对照组和XN(H)组,差异具有统计学意义(P＜0.01),而且模型组与XN(L)组的GABA水平之间也存在显著性差异(P＜0.05).结论:鸟灵菌粉水提物对MCAO模型小鼠海马结构具有保护作用,这一作用可能与其调节GABA和BDNF水平有关.%Objective:To investigate the effects of aqueous extract from oxylaria nigripes (XN) on the morphosis and BDNF and GA-BA levels in hippocampus during cerebral ischemia-reperfusion in mice.Methods:The Kunming mice were randomly divided into 4 groups:sham,MCAO,XN (L) and XN (H) group.The mice in sham group were received fake surgery and saline,MCAO and XN groups were exposed to middle cerebral artery occlusion (MCAO),and received saline or XN (300 or 600 mg/kg) immediately after the operation.Nissl staining was performed and the expression of NF-H of hippocampus was assessed at 24 h after reperfusion.In addition,the levels of BDNF and GABA were estimated by Elisa.Results:(1) There were obviously cavity like change and neuronal damage in the dentate gyms and CA1 ofhippocampus in MCAO group.And this morphological change was relieved in XN (H) group.(2) The expression of NF-H in MCAO group was significantly reduced when compared with that of sham and XN (H) group (P＜0.05).(3) The result of Elisa showed that the levels of BDNF and GABA in MCAO group was significantly lower than that of sham and XN (H) group (P＜0.01),and there was also significant difference between MCAO and XN (L) group in the levels of BDNF and GABA (P＜0.05).Conclsion:The aqueous extract from oxylaria nigripes could protect the cellular damage and nerve fiber in the hippocampus of mice after middle cerebral artery occlusion,and the regulation of BDNF and GABA may play a critical role in this protective effect of XN.