氧化苦参碱介导细胞自噬减轻溃疡性结肠炎小鼠结肠黏膜氧化性损伤的作用机制研究

目的 探讨氧化苦参碱介导细胞自噬减轻溃疡性结肠炎（ulcerative colitis，UC）小鼠结肠黏膜氧化性损伤的作用机制。方法 采用2，4，6-三硝基苯磺酸灌肠复制小鼠UC模型，将造模成功小鼠按体质量随机分为模型组、氧化苦参碱组（50 mg·kg^-1·d^-1，ig）、羟基氯喹组（50 mg·kg^-1·d^-1，ig）、氧化苦参碱+羟基氯喹组，另设正常组，每组10只。治疗1周后测定各组小鼠疾病活动度（disease activity，DAI）、结肠质量系数及病理形态；MitoSOX Red法测定结肠ROS含量，ELISA法测定结肠组织SOD、MDA、MPO、GSH-PX含量；透射电镜结合免疫荧光观测结肠细胞自噬程度，Western blot测定Atg5和Beclin-1蛋白表达。结果 与模型组和羟基氯喹组比较，氧化苦参碱组小鼠DAI和结肠质量系数均有显著减小（P<0.01），结肠病理损伤明显减轻；ROS、MDA和MPO含量极显著降低（P<0.01），SOD和GSH-PX含量极显著增加（P<0.01）；结肠黏膜细胞自噬，程度显著增强，Atg5和Beclin-1蛋白表达极显著上调（P<0.01）。结论 氧化苦参碱可促进UC小鼠细胞自噬，减轻小鼠结肠黏膜氧化性损伤。

Mechanism of Oxymatrine Alleviating Oxidative Damage of Colonic Mucosal Cells by Regulating Autophagy in Ulcerative Colitis Mice

OBJECTIVE To investigate the mechanism of oxymatrine reducing oxidative damage of colonic mucosal via controlling cell autophagy ulcerative colitis(UC) mice. METHODS UC model was induced by 2,4,6-trinitrobenzenesulfonic acid. Mice of successful model were randomly divided into model group, oxymatrine group(50 mg·kg^-1·d^-1, ig), hydroxychloroquine group(50 mg·kg^-1·d^-1, ig) and oxymatrine + hydroxychloroquine group of 10 animals in each group, normal group was also set. One week after the treatment, the disease activity(DAI), the colon weight index and pathomorphology were determined; the colon ROS content was determined by MitoSOX Red method; the contents of SOD, MDA, MPO and GSH-PX in the colon tissues were determined by ELISA method; the degree of autophagy of colonic cells was observed by electron microscope and immunofluorescence; the expression of Atg5 and Beclin-1 proteins were detected by Western blot. RESULTS Compared with the model group and the hydroxychloroquine group, the DAI and the colonic weight index of oxymatrine group were significantly decreased(P<0.01), and the colonic pathological damage was significantly reduced; the contents of ROS, MDA and MPO were significantly decreased(P<0.01); the contents of SOD and GSH-PX were significantly increased(P<0.01). The degree of autophagy in colonic mucosa was significantly increased, and the expressions of Atg5 and Beclin-1 were significantly upregulated(P<0.01). CONCLUSION Oxymatrine can reduce the oxidative damage of colonic mucosa by promoting autophagy in UC mice.