基于TLR4/NF-κB信号通路探讨醒脑静改善反复缺血-再灌注脑损伤小鼠学习记忆能力的作用研究

Effect of Xingnaojing on Learning and Memory in Mice with Repeated Ischemia-reperfusion Brain Injury Based on TLR4/NF-κB Signaling Pathway

目的:探讨醒脑静通过TLR4/NF-κB信号通路改善反复缺血-再灌注(I/R)脑损伤小鼠学习记忆能力的作用。方法:将50只雄性C57BL/6小鼠随机分为假手术组、模型组,醒脑静低、中、高剂量组,制备大鼠脑反复I/R损伤模型。造模成功2 h后,醒脑静低、中、高剂量组分别给予醒脑静注射液1、5、10 mL/kg进行腹腔注射,1次/d,连续给药7 d。假手术组和模型组腹腔给予等容量生理盐水。用Morris水迷宫实验检测小鼠的学习记忆能力,对脑组织进行TTC染色,检测脑组织中TNF-α、IL-1β、IL-6、TLR4、NF-κB和IκBα表达。结果:与假手术组相比,模型组小鼠逃避潜伏期的时间和脑梗死体积均显著升高,脑组织中TNF-α、IL-1β、IL-6、TLR4、NF-κB和IκBα表达均显著升高,穿越平台次数显著降低(P<0.05);与模型组相比,各醒脑静治疗组小鼠逃避潜伏期的时间和脑梗死体积均显著降低,脑组织中TNF-α、IL-1β、IL-6、TLR4、NF-κB和IκBα表达均显著降低,穿越平台次数显著增加(P<0.05),且随药物剂量增大而变化(P<0.05)。结论:醒脑静能减小脑梗死体积,改善反复脑I/R损伤小鼠学习记忆能力,其机制可能与抑制脑组织中TLR4/NF-κB信号通路,减轻炎症刺激有关。

Objective:To investigate the effect of Xingnaojing on learning and memory in mice with repeated ischemia-reperfusion brain injury based on TLR4/NF-κB signaling pathway.Method:Fifty male C57 BL/6 mice were randomly divided into sham-operated group and model group,and Xingnaojing low,medium and high dose groups.The brain repeated I/R injury model were established.Two hours after the successful establishment of the model,Xingnaojing low,medium and high dose groups were given intraperitoneal injection of 1,5 and 10 mL/kg respectively,once a day for 7 days.The sham-operated group and model group were given intraperitoneal saline of equal volume.Morris water maze test was used to detect the learning and memory ability of mice.TTC staining was used to detect the expression of TNF-α,IL-1β,IL-6,TLR4,NF-κB and IκBα in brain tissue.Result:Compared with the sham-operated group,the time of escape latency and the volume of cerebral infarction in the model group were significantly increased,and the expressions of TNF-α,IL-1β,IL-6,TLR4,NF-κB and IκBα in brain tissue were significantly increased,and the times of crossing the platform were significantly decreased(P<0.05).Compared with the model group,the time of escape latency and the volume of cerebral infarction in the Xingnaojing treatment group were significantly decreased,and the expressions of TNF-α,IL-1β and IL-6 in brain tissue were significantly decreased,and the expression of TLR4,NF-κB and IκBα decreased significantly,and the number of times crossing the platform increased significantly(P<0.05),and changed with the increase of drug dosage(P<0.05).Conclusion:Xingnaojing can reduce the volume of cerebral infarction and improve the learning and memory ability of mice with repeated brain I/R injury.Its mechanism may be related to inhibiting TLR4/NF-κB signaling pathway in brain tissue and alleviating inflammatory stimulation.