甘草查尔酮A对局灶性脑缺血再灌注小鼠Nrf2/HO-1信号通路和神经炎症反应的影响

Effects of Licochalcone A on the Nrf2/HO-1 Signaling Pathway and Neuroinflammation after Cerebral Ischemia/Reperfusion in Mice

目的:探讨甘草查尔酮A对局灶性脑缺血再灌注小鼠Nrf2/HO-1信号通路和神经炎症反应的影响。方法:体重23~25 g的雄性C57BL/6小鼠总计96只,随机分为4组(n=24):假手术对照组(Sham组)、脑缺血再灌注组(MCAO组)、溶剂组(Vehicle组)、甘草查尔酮A组(LA组)。采用大脑中动脉栓塞(MCAO)模型致大鼠脑缺血损伤。72 h后行神经功能学评分,2,3,5-三苯基氯化铵(TTC)染色检测脑梗死体积,Western blot法检测脑Nrf2、HO-1、TNF-α、IL-6蛋白表达水平,TUNEL染色法检测凋亡细胞数。结果:与Sham组比较,MCAO组和Vehicle组小鼠神经功能评分明显降低(P<0.05),脑梗死体积显著增加(P<0.05),而核蛋白Nrf2和胞浆蛋白HO-1蛋白表达水平较低(P<0.05),炎症因子IL-6和TNF-α表达水平明显增加(P<0.05),脑实质炎性细胞浸润显著增多(P<0.05);与MCAO组和Vehicle组比较,LA组小鼠神经功能评分明显增加(P<0.05),脑梗死体积显著减少(P<0.05),而核蛋白Nrf2和胞浆蛋白HO-1蛋白表达水平更高(P<0.05),炎症因子IL-6和TNF-α表达水平明显减少(P<0.05),脑实质炎性细胞浸润明显减少(P<0.05)。结论:甘草查尔酮A可缓解脑缺血再灌注损伤后出现的神经炎症反应及细胞凋亡,进而减轻神经功能障碍和脑梗死体积,其机制可能与激活Nrf2/HO-1信号通路相关。

Objective: To investigate the effect of licochalcone A on the Nrf2/HO-1 signaling pathway and neuroinflammation after cerebral ischemia/reperfusion in mice. Methods: A total of 96 male C57 BL/6 mice weighing 23~25 g were randomly divided into 4 groups: sham-operated control group(Sham group), cerebral ischemia/reperfusion group(MCAO group), Vehicle group, licochalcone A group(LA group). The middle cerebral artery occlusion(MCAO) model was used to produce acute cerebral ischemia in the mice. Seventy-two hours after MCAO surgery, the neurological function was evaluated, the infarct volume was estimated by using triphenyltetrazolium(TTC) staining, the cellular apoptosis was calculated by applying the TUNEL assay, the protein levels of Nrf2, HO-1, TNF-α and IL-6 were determined in the ischemia brain by western blot. Results: Compared with the Sham group, the neurological scores of the MCAO group and the Vehicle group were significantly lower(P<0.05), the cerebral infarction volume was significantly increased(P<0.05),and the nuclear protein Nrf2 and cytosolic protein HO-1 protein expression levels were lower(P<0.05), IL-6 and TNF-α expression levels increased significantly(P<0.05), and the infiltration of inflammatory cells in the brain parenchyma was increased(P<0.05);In comparison with the MCAO group and Vehicle group, the mice in the LA group exhibited a significant increase in neurological function scores(P<0.05),the cerebral infarct volume was significantly reduced(P<0.05), the expression levels of nuclear protein Nrf2 and cytosolic protein HO-1 were elevated(P<0.05), the expression levels of IL-6 and TNF-α were substantially decreased(P<0.05), and the infiltration of inflammatory cells in the brain parenchyma was reduced(P<0.05). Conclusions: The treatment of licochalcone A can alleviate neuroinflammation and apoptosis, thereby reducing neurological dysfunction and infarction volume after cerebral ischemia/reperfusion injury. Its mechanism may be associated with activation of Nrf2/HO-1 signaling pathway.