葛根素通过抑制TLR4信号通路改善LPS诱导的认知障碍

PuerarinAlleviates LPS-induced Cognition Dysfunction by Inhibiting TLR4 Pathway

目的:研究葛根素对LPS诱导的脓毒症小鼠认知功能的影响。方法:将30只C57BL/6小鼠随机分为3组(每组10只):对照组(control组)、造模组(LPS+Vehicle组)、治疗组(LPS+Puerarin组)。对照组小鼠腹腔注射等体积的生理盐水;造模组小鼠腹腔注射LPS 5 mg/kg;治疗组小鼠腹腔注射LPS 5 mg/kg,并在注射前2小时和注射后第2、3天通过腹腔注射葛根素100 mg/kg。LPS注射后72小时,通过Y迷宫测试对小鼠的认知功能进行检测,使用组织血流扫描成像仪观察小鼠的脑组织灌注情况,用Western Blot检测TLR4及其下游信号分子的表达,并通过免疫荧光染色检测脑组织中小胶质细胞的改变。结果:与对照组相比,造模组小鼠的认识功能出现显著下降(P<0.05),脑组织血流灌注降低(P<0.05),TLR4/MYD88/TRAF6的表达明显升高(P<0.05),小胶质细胞出现显著活化(P<0.05)。与造模组对比,治疗组小鼠的认知功能得到显著改善(P<0.05),脑组织灌注明显升高(P<0.05),TLR4/MYD88/TRAF6的表达显著降低(P<0.05),小胶质细胞的活化也得到改善(P<0.05)。结论:葛根素通过抑制TLR4/MYD88/TRAF6信号通路改善LPS诱导的小胶质细胞活化,提高脓毒症小鼠的脑血流,改善了小鼠的认知功能。

Objective:To investigate the effect of puerarin on cognition function in LPS-induced sepsis mice.Methods:Thirty C57BL/6 mice were randomly divided into 3 groups (10 mice in each group):Control group,Model group (LPS+Vehicle group)and Treatment group(LPS+Puerarin group). Mice of control group received intraperitoneal injection with normal saline in equal volume while mice ofmodel groupreceived intraperitoneal injection with 5 mg/kg LPS. Meanwhile,mice of treatment group was intraperitoneally injected with 100 mg/kg puerarin 2 hours before and the second and third day after intraperitonealinjection with 5 mg/kg LPS.72 hours after LPS injection,Y maze was used to detect the cognition function of mice and tissue blood perfusion imager was used to assessthe brain blood perfusion of mice. The expression of TLR4 and downstream signal molecules were detected by Western blot and change of microglia in brain was assessed by immunofluorescence staining. Results:Compared with mice of control group,cognition function was significantly impaired (P<0.05) and brain blood perfusion declined significantly (P<0.05) in mice of model group.Increased expression of TLR4/MYD88/TRAF6 (P<0.05) and activation of microglia (P<0.05) in mice of model group were also significant statistically compared with mice of control group. When comparison was drew with mice of model group,cognition impairment (P<0.05) and decline of brain blood perfusion (P<0.05) were significantly alleviated in mice of treatment group while the expression of TLR4/MYD88/TRAF6 (P<0.05)and activation of microglia (P<0.05) in mice of treatment group were also significantly decreased. Conclusion:Puerarin inhibits LPS-induced microglia activation via suppressing TLR4/MYD88/TRAF6 pathway,increases the brain blood perfusion of sepsis mice and thus alleviates LPS-induced cognition dysfunction.