小儿开胃增食合剂对厌食症幼龄大鼠肠黏膜屏障的保护作用及机制研究

Study on the Protective Effect and Mechanism of Xiaoer Kaiwei Zengshi Mixture on Intestinal Mucosal Barrier in Young Rats with Anorexia

目的探讨小儿开胃增食合剂(苍术、茯苓、鸡内金、乌梅等)对厌食症幼龄大鼠肠黏膜屏障的保护作用及机制。方法将50只SD幼龄大鼠随机分为正常组、模型组、益生菌组(双歧杆菌四联活菌片,0.405 g·kg^(-1))及中药高、低剂量组(小儿开胃增食合剂,11.4、5.7 g·kg^(-1)),每组10只。采用病因模拟法复制厌食症幼龄大鼠模型,通过摄食量、体质量变化评价模型复制效果。灌胃给药(10 mL·kg^(-1)),每天1次,连续42 d。采用HE染色法观察结肠组织病理变化;透射电镜观察肠黏膜屏障超微结构;ELISA法检测血清白细胞介素22(IL-22)水平;RT-PCR及Western Blot法检测结肠组织中密封蛋白1(Claudin-1)、闭合蛋白(Occludin)、闭锁小带蛋白1(ZO-1)mRNA及蛋白表达水平。结果与正常组比较,模型组大鼠摄食量、体质量明显降低(P<0.05);结肠黏膜损伤严重,细胞间连接部分断裂,桥粒密度下降;血清IL-22水平显著降低(P<0.01);结肠组织中Claudin-1、Occludin、ZO-1 mRNA和蛋白表达均显著下调(P<0.01)。与模型组比较,各给药组大鼠的摄食量、体质量明显升高(P<0.05);结肠黏膜损伤程度减轻,细胞间连接均有不同程度的恢复;血清IL-22水平显著升高(P<0.01);结肠组织中Occludin、ZO-1蛋白表达均明显上调(P<0.05,P<0.01);益生菌组、中药高剂量组大鼠结肠组织中Claudin-1、Occludin、ZO-1 mRNA表达及Claudin-1蛋白表达明显上调(P<0.05,P<0.01)。结论小儿开胃增食合剂可能通过调节IL-22水平及肠道屏障相关紧密连接蛋白Claudin-1、Occludin、ZO-1表达,对厌食症幼龄大鼠肠黏膜屏障发挥保护作用,从而增加其摄食量和体质量。

Objective To study the protective effect and mechanism of Xiaoer Kaiwei Zengshi Mixture(Atractylodis Rhizoma,Foria,Calli Gigerii Endothelium Corneum,Mume Fructus,etc.)on the intestinal mucosal barrier of young rats with anorexia.Methods A total of 50 SD young rats were randomly divided into normal group,model group,probiotic group(Bifidobacterium quadruplex viable tablets,0.405 g·kg^(-1)),Xiaoer Kaiwei Zengshi Mixture high-and low-dose groups(11.4,5.7 g·kg^(-1)),with 10 rats in each group.The etiological simulation method was used to establish a young rat model of anorexia,and the modeling effect was evaluated by recording changes in food intake and body mass.After intragastric administration(10 mL·kg^(-1),once a day)for 42 days,the pathological changes of colon tissue were observed by HE staining.The ultrastructure of intestinal mucosal barrier was observed by transmission electron microscopy.The level of serum IL-22 was detected by ELISA.The mRNA and protein expressions of Claudin-1,Occludin,and ZO-1 in the colon tissues were detected by RT-PCR and Western Blot.Results Compared with the normal group,rats in the model group exhibited a significant decrease in food intake and body mass(P<0.05)and severe damage to the colonic mucosa,with partial rupture of intercellular junctions in the colonic mucosa and decreased density of desmosomes.Serum IL-22 level was significantly reduced(P<0.01).The mRNA and protein expressions of Claudin-1,Occludin,and ZO-1 in the colonic tissues were significantly down-regulated(P<0.01).Compared with the model group,the food intake and body mass of the rats in the treatment groups were significantly increased(P<0.05).It has been shown that the degree of damage to the colonic mucosal was reduced,and the intercellular junctions of the colonic mucosa were repaired in various degrees.The level of serum IL-22 was significantly increased(P<0.01),and the protein expressions of Occludin,and ZO-1 in the colonic tissues were significantly up-regulated(P<0.05,P<0.01).The mRNA expressions of Claudin-1,Occludin,and ZO-1 and the protein expression of Claudin-1 of the colonic tissues in probiotic group and Xiaoer Kaiwei Zengshi Mixture high-dose group were significantly up-regulated(P<0.05,P<0.01).Conclusion Xiaoer Kaiwei Zengshi Mixture has a protective effect on the intestinal mucosal barrier of young rats with anorexia by regulating IL-22 level and the expression of intestinal barrier-related tight junction proteins,including Claudin-1,Occludin,and ZO-1,thereby increasing food intake and body mass.