延龄草总皂苷对血管性认知障碍的干预作用及其机制

Effects of total saponins from Trillium tschonoskii Maxim on vascular cognitive impairment and its mechanisms

目的:探讨延龄草总皂苷(TST)通过内质网应激(ERS)调控NOD样受体蛋白3(NLRP3)炎症小体对血管性认知障碍(VCI)大鼠神经保护作用。方法:将60只雄性SD大鼠分为4组(n=10):假手术组(Sham)、模型组(VCI,双侧颈总动脉结扎(BCCAO)法)、TST干预组(TST,100 mg/kg)以及盐酸多奈哌齐阳性组(Positive,0.45 mg/kg),连续给药4周。Morris水迷宫评价学习记忆能力;HE、Nissl染色观察组织形态变化;Western blot法检测内质网相关蛋白GRP78、IRE1、XBP1;炎症小体相关蛋白NLRP3、ASC、Caspase-1、IL-18、IL-1β。结果:与Sham组相比,VCI组大鼠逃避潜伏期明显延长,穿越平台次数与目标象限停留时间百分比缩短(P<0.01);VCI大鼠海马区细胞损伤,出现明显核固缩现象、神经元数量减少,胞体结构损伤;VCI组内质网、炎症小体相关蛋白上升(P<0.05或P<0.01);与VCI组比较,TST组与Positive组寻台时间减少,穿越平台次数与占目标象限时间比值延长(P<0.05或P<0.01),其中Positive组与VCI组相比穿越平台次数差异不明显(P>0.05);TST组与Positive组细胞损伤、核固缩明显减轻、神经元数量明显增多;TST组与Positive组内质网相关蛋白、炎症小体相关蛋白不同程度降低(P<0.05或P<0.01)。结论:TST对VCI大鼠具有神经保护作用,其机制可能与ERS参与调控NLRP3炎症小体的途径有关。

Objective:To investigate neuroprotective effects of total saponins from Trillium tschonoskii Maxim(TST)on vascular cognitive impairment(VCI)rats through inflammatory body of the NOD-like body protein 3(NLRP3)regulated by endoplasmic reticulum stress(ERS).Methods:SD rats were divided into sham-operated group(SHAM),model group(VCI,bilateral neck arterial ligation(BCCAO)method),TST intervention group(TST,100 mg/kg),and positive group(donepezil hydrochloride,0.45 mg/kg),continuous administration for 4 weeks.The ability of learning and memory was evaluated by the morris water labor.The tissue pathological changes were observed by HE and NISSL staining.Western blot was used to detect endoplasmic reticulum-related proteins GRP78,IRE1,XBP1.Inflammasome-related proteins NLRP3,ASC,Caspase-1,IL-18,IL-1β.Results:Compared with the SHAM group,the escape latency of VCI group rats was prolonged significantly,and the number of times of crossing the platform and the percentage of target quadrant residence time were shortened(P<0.01);The cells in the hippocampus of VCI rats were damaged,with obvious pyknosis,decreased number of neurons and damage of cell body structure;The endoplasmic reticulum and inflammatory corpuscle-associated proteins were increased in VCI group(P<0.05 or P<0.01).Compared with the VCI group,the TST group and the positive group had less time to search for the platform,and the ratio of the times of crossing the platform to the time in the target quadrant was longer(P<0.05 or P<0.01).There was no significant difference in the times of crossing the platform between the positive group and VCI group(P>0.05);The cell damage,nuclear pyknosis and the number of neurons in TST and positive groups were significantly reduced;The endoplasmic reticulum associated proteins and inflammatory body associated proteins in TST group and positive group were decreased to different degrees(P<0.05 or P<0.01).Conclusion:TST has neuroprotective effects on VCI rats,and its mechanism may be related to the involvement of ERS in the regulation of NLRP3 inflammatory small bodies.