基于Keap1/Nrf2信号通路介导的氧化应激损伤探讨三七总皂苷对七氟烷麻醉后大鼠认知功能障碍的影响

Effect of PNS on Cognitive Dysfunction after Sevoflurane Anesthesia in Rats Based on Oxidative Stress Damage Mediated by Keap1/Nrf2 Signaling Pathway

目的:观察三七总皂苷(PNS)对七氟烷麻醉后大鼠认知功能障碍的作用,并探讨可能机制。方法:40只SD大鼠,随机选取10只设为Blank组,其余大鼠建立七氟烷麻醉认知障碍模型,随机分为Sevoflurane组、PNS组、PNS联合ML385[Kelch样环氧氯丙烷相关蛋白1(Keap1)/核因子E2相关因子2(Nrf2)信号通路抑制剂]组,各10只。PNS联合ML385组大鼠腹腔注射PNS(75 mg/kg)、ML385(20 mg/kg);PNS组大鼠腹腔注射PNS(75 mg/kg)、等体积二甲基亚砜(DMSO);Blank组、Sevoflurane组大鼠腹腔注射等量生理盐水、等体积DMSO。每日1次,持续14 d。采用T迷宫实验检测认知功能;检测血清氧化应激指标丙二醛(MDA)、谷胱甘肽(GSH)、超氧化物歧化酶(SOD)水平;Western Blot法检测脑组织Keap1、Nrf2蛋白表达。结果:与Sevoflurane组比较,PNS组大鼠T迷宫实验成功率,GSH、SOD活性,Nrf2蛋白表达升高,MDA水平、Keap1蛋白表达降低(P <0.05);与PNS组比较,PNS联合ML385组大鼠T迷宫实验成功率,GSH、SOD活性,Nrf2蛋白表达降低,MDA水平、Keap1蛋白表达升高(P <0.05)。结论:PNS可改善七氟烷麻醉后大鼠认知功能障碍,抑制脑组织氧化应激反应,推测其作用机制可能与激活Keap1/Nrf2信号通路有关。

Objective:To observe the effect of panax notoginseng saponins(PNS)on cognitive dysfunction after sevoflurane anesthesia in rats,and to explore the possible mechanism. Methods:10 rats were randomly selected from 40 SD rats as the blank control,the rest rats were established the model of cognitive dysfunction after sevoflurane anesthesia,then assigned into the Sevoflurane group,the PNS group and the PNS combined ML385[Kelch-like epichlorohydrin-related protein 1(Keap1)/Nuclear factor E2-related factor 2(Nrf2)signaling pathway inhibitor] group. Rats in the PNS combined with ML385 group were intraperitoneally injected with PNS(75 mg/kg)and ML385(20 mg/kg). Rats in the PNS group were intraperitoneally injected with PNS(75 mg/kg)and equal volume of dimethyl sulfoxide(DMSO). Rats in the blank group and the Sevoflurane group were intraperitoneally injected with the same amount of normal saline and the same volume of DMSO. The intervention was once a day for 14 days. The T-maze experiment was used to detect cognitive function. The serum levels of oxidative stress indicators,such as malondialdehyde(MDA),glutathione(GSH) and superoxide dismutase(SOD),were tested. Western Blot was applied to detect the protein expressions of Keap1 and Nrf2 in brain tissues. Results:Compared with those in the Sevoflurane group,the success rate of the T-maze experiment,the activities of GSH and SOD,and the protein expressions of Nrf2were increased,whereas the level of MDA and the protein expression of Keap1 were decreased in the PNS group(P < 0. 05). Compared with those in the PNS group,the success rate of the T-maze experiment,the activities of GSH and SOD,and the protein expression of Nrf2 were decreased,whereas the level of MDA and the protein expression of Keap1 were increased in the PNS combined with ML385 group(P < 0. 05).Conclusion:PNS can improve the cognitive dysfunction of rats after sevoflurane anesthesia and inhibit the oxidative stress response in brain tissues. It is speculated that its mechanism may be related to the activation of Keap1/Nrf2 signaling pathway.