复方肠泰制剂对溃疡性结肠炎小鼠肠黏膜屏障的保护作用

摘要

目的：观察复方肠泰制剂在小鼠溃疡性结肠炎中对肠黏膜屏障的保护作用，并探讨其作用机制。方法建立葡聚糖硫酸钠诱导小鼠实验性溃疡性结肠炎模型，实验分为空白组、模型组、不同剂量治疗组（4．3 g／kg与17．1 g／kg）、美沙拉嗪对照组和硫唑嘌呤对照组。造模7d内，观察记录各组小鼠体质量和疾病活动指数变化；采用透射电镜观察各组小鼠结肠的超微结构；HE染色观察各组小鼠炎症；ELISA法测定各组小鼠结肠组织TNF-α、IL-6、IFN-γ、IL-10；蛋白质印迹方法检测各组小鼠结肠组织中ZO-1、Occludin和Claudin-1蛋白的表达。结果模型组小鼠体质量、DAI和结肠长度与空白对照组比较，差异均有统计学意义（P＜0．05）；结肠组织中TNF-α、IL-6和IFN-γ水平显著降低，差异有统计学意义（P＜0．05）；组织病理显示炎性细胞明显浸润，ZO-1、Occludin和Claudin-1蛋白的表达显著下降，差异有统计学意义（P＜0．05）；高剂量复方肠泰组与空白对照组比较，差异均无统计学意义（P＞0.05）。结论高剂量复方肠泰制剂对小鼠肠黏膜屏障功能具有一定的保护作用，其机制可能与肠上皮紧密连接蛋白表达升高以及肠道免疫功能调节有关。%Objective To verify the protective effect of compound Changtai on the intestinal mucosal barrier in the treatment of ulcerative colitis ( UC) , and also to explore the possible mechanism involved.Methods The animal model of ulcerative colitis in-duced by dextran sodium sulfate ( DSS) was established as a first step.The experimental animals were divided into 6 groups, i.e.the blank control group, the model group, the compound Changtai treatment groups with two different dosages (4.3 g/kg, 17.1g/kg), the mesalazine and azathioprine control groups.Seven days after the development of the model, changes in body weight and disease activity index ( DAI) were observed and recorded.Colon ultrastructures in the animals of various groups were closely observed by transmission electron microscopy;inflammation in the animals of various groups was observed by HE staining;the levels of TNF-α, IL-6, IFN-γand IL-10 in the colon of various animal groups were detected by ELISA;and the expression levels of ZO-1, Occludin and Claudin-1 in the colon of various groups were detected by Western blot.Results Significant differences could be seen in the body weight, DAI, colon length in the animals of the model group, as compared with those of the control group(P<0.05).The levels of TNF-α,IL-6 and IFN-γin the colon were significantly decreased(P<0.05), and the expression levels of Occludin, Claudin-1 and ZO-1 were also signifi-cantly decrease(P<0.05).Histopathological detection indicated that inflammatory infiltration was evident.Transmission electron mi-croscopy detection showed a damaged opening dot in the tight junction protein in the colon of the model group.No significant differences could be noted, when comparisons were made between the high dosage Changtai group and the blank control group(P <0.05). Conclusion The high dosage compound Changtai seemed to have certain protective effect on the intestinal mucosal barrier, the possi-ble mechanism involved might be related with the increased expression level of the tight junction protein and the regulation of intestinal immune function.