目的 探討牡荊苷通過調(diào)控核轉錄因子E2相關因子2（Nrf2）/抗氧化反應元件（ARE）通路對急性腦缺血再灌注大鼠氧化應激反應的作用。方法 54只SD大鼠隨機分為假手術組、模型組、陽性對照依達拉奉（0.56 mg/kg）組和牡荊苷低、中、高劑量（10、20、40 mg/kg）組，除假手術組外均制備急性腦缺血大鼠模型，再灌注后假手術組、模型組大鼠ip生理鹽水，依達拉奉組和牡荊苷各劑量組按照相應劑量ip給藥，8 h給藥1次，共3次。對比干預前后大鼠神經(jīng)行為學評分；HE染色檢測大鼠大腦皮質(zhì)病理變化；試劑盒檢測大鼠大腦皮質(zhì)組織氧化應激指標丙二醛（MDA）、一氧化氮（NO）、超氧化物歧化酶（SOD）、谷胱甘肽（GSH）水平；實時熒光定量PCR（qRT-PCR）和Western blotting檢測大鼠大腦皮層Nrf2/ARE通路相關基因mRNA與蛋白表達水平。結果 干預前后假手術組大鼠神經(jīng)行為學評分無明顯變化，模型組較干預前增高（P<0.01），依達拉奉組、牡荊苷各劑量組均較干預前降低（P<0.01），且干預后各組間神經(jīng)行為學評分比較差異顯著（P<0.01）。假手術組大鼠大腦皮質(zhì)組織神經(jīng)細胞分布均勻、密集，神經(jīng)細胞的胞體、胞核形態(tài)正常；模型組、依達拉奉組和牡荊苷各劑量組大鼠腦組織神經(jīng)細胞排列均有紊亂、疏松，其中模型組可見液化性壞死、細胞結構消失等表現(xiàn)；牡荊苷低劑量組可見細胞排列嚴重紊亂、疏松，部分液化性壞死、細胞結構消失；牡荊苷中劑量組和依達拉奉組液化性壞死部分面積小，大多細胞結構正常；牡荊苷高劑量組僅可見極少液化性壞死，細胞結構基本正常，細胞排列輕微紊亂。與假手術組比較，模型組大鼠大腦皮質(zhì)MDA和NO水平顯著升高（P<0.01），SOD和GSH水平顯著降低（P<0.01），Nrf2、γ-GCS mRNA表達水平顯著升高（P<0.01），細胞質(zhì)Nrf2、γ-GCS蛋白表達水平均顯著升高（P<0.01），細胞核Nrf2、HO-1蛋白表達水平均顯著降低（P<0.01）。與模型組比較，依達拉奉組和牡荊苷低、中、高劑量組大鼠大腦皮質(zhì)MDA和NO水平均顯著降低（P<0.01），SOD和GSH水平顯著升高（P<0.01），Nrf2、γ-GCS mRNA表達水平顯著降低（P<0.01），細胞質(zhì)Nrf2、γ-GCS蛋白表達水平均顯著降低（P<0.01），細胞核Nrf2、HO-1蛋白表達水平均顯著升高（P<0.01）。且牡荊苷各劑量組大鼠大腦皮質(zhì)MDA、NO、SOD、GSH水平及Nrf2、γ-GCS、HO-1 mRNA和蛋白表達水平均呈劑量依賴性，組間差異顯著（P<0.01）。結論 牡荊苷可減輕急性腦缺血再灌注大鼠氧化應激反應，推測與調(diào)控Nrf2/ARE信號通路，上調(diào)Nrf2基因與蛋白表達，促進其由細胞質(zhì)向細胞核移動，上調(diào)HO-1表達，抑制γ-GCS表達，增強機體的抗氧化應激反應能力有關。

Objective To investigate the effect of vitexin on oxidative stress in rats with acute cerebral ischemia-reperfusion by regulating the pathway of nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE). Methods A total of 54 SD rats were randomly divided into Sham group, model group, positive control (edaravone 0.56 mg/kg) group and vitexin low, medium, and high dose (10, 20, 40 mg/kg) groups. The rat models with acute cerebral ischemia were established except the Sham group. After reperfusion, rats in Sham group and model group were received ip saline. The edaravone group and vitexin groups were administered according to the corresponding dose, once every 8 h for a total of three times. The neurobehavioral scores of rats before and after intervention were compared. HE staining was used to detect the pathological changes of cerebral cortex. The levels of MDA, NO, SOD, and GSH in cerebral cortex of rats were detected by the kit. The mRNA and protein expression levels of Nrf2/ARE pathway related gene in rat cerebral cortex were detected by real-time fluorescent quantitative PCR (qRT-PCR) and Western blotting. Results Before and after intervention, there was no significant change in the neurobehavioral score of rats in the Sham group, the model group was higher than before intervention (P<0.01), the edaravone group and the vitexin groups were lower than before intervention (P<0.01), and there was a significant difference in the neurobehavioral score between the groups after intervention (P<0.01). In the Sham group, the distribution of nerve cells was uniform and dense, and the morphology of cell body and nucleus was normal. In the model group, edaravone group and vitexin group, the arrangement of brain tissue was disordered and loose, in which liquefying necrosis and disappearance of cell structure were observed in the model group; in the low-dose group, the arrangement of cells was seriously disordered and loose. In the vitexin medium dose group and edaravone group, the area of liquefying necrosis was small, and most of the cells were normal; In the vitexin high dose group, only a few liquefying necrosis were found, the cell structure was basically normal, and the cell arrangement was slightly disordered. Compared with the Sham group, the levels of MDA and NO in the cerebral cortex of the model group were significantly increased (P<0.01), the levels of SOD and GSH were significantly reduced (P<0.01), and the expression levels of Nrf2 and γ-GCS mRNA were significantly increased (P<0.01), the expression of cytoplasmic Nrf2 and γ-GCS proteins were significantly increased (P<0.01), and the expression levels of nuclear Nrf2 and HO-1 proteins were significantly decreased (P<0.01). Compared with the model group, the levels of MDA and NO in the cerebral cortex of rats in the edaravone group and low, medium and high dose groups of vitexin were significantly reduced (P<0.01), and the levels of SOD and GSH were significantly increased (P<0.01), Nrf2 and γ-GCS mRNA expression levels were significantly reduced (P<0.01), cytoplasmic Nrf2, γ-GCS protein expressions were significantly reduced (P<0.01), and nuclear Nrf2 and HO-1 protein expression levels were significantly increased (P<0.01). And the levels of MDA, NO, SOD, GSH and Nrf2, γ-GCS, HO-1 mRNA and protein expression in rat cerebral cortex in each dose group were dose-dependent, with significant differences between groups (P<0.01). Conclusion Vitexin can alleviate oxidative stress in rats with acute cerebral ischemia-reperfusion. It is speculated that it is related to the regulation of Nrf2/ARE signaling pathway, the up-regulation of Nrf2 gene and protein expression, the promotion of its movement from cytoplasm to nucleus, the up-regulation of HO-1 expression, the inhibition of γ-GCS expression, and the enhancement of the body's ability to response to oxidative stress.

R285.5