肠炎宁对猪大肠杆菌肠道感染的保护作用

Protective Effect of Changyanning on Intestinal Infection with Swine Escherichia coli

为评价中药肠炎宁对猪大肠杆菌感染小鼠肠道的保护效果,并初步研究其机制,本试验将SPF级BALB/c小鼠随机分为空白对照组、大肠杆菌K88组和肠炎宁组3个组,大肠杆菌K88组和肠炎宁组小鼠通过口服产肠毒素性大肠杆菌K88诱导腹泻模型,12 h后分别灌服生理盐水和肠炎宁药液,连续给药3 d,检测不同组别小鼠的存活时间、体重变化、肠道病理变化、结肠长度变化、肠道通透性和炎症因子等指标变化,并分析炎症因子信号通路蛋白表达情况。结果显示,与空白对照组相比,大肠杆菌K88组小鼠出现死亡,存活时间显著缩短(P<0.05),体重显著下降(P<0.05),结肠显著缩短(P<0.05),肠道通透性和血清髓过氧化物酶(MPO)活性显著升高(P<0.05),血清和结肠组织中TNF-α和IL-1β水平显著升高(P<0.05);与大肠杆菌K88组相比,肠炎宁组小鼠存活时间显著延长(P<0.05),体重显著增加(P<0.05),结肠显著增长(P<0.05),肠道通透性和血清MPO活性显著下降(P<0.05),血清和结肠组织中TNF-α和IL-1β水平显著下降(P<0.05);组织病理学观察结果显示,肠炎宁可缓解大肠杆菌K88感染导致的结肠杯状细胞肿大和炎性细胞浸润;免疫组化结果显示,肠炎宁可抑制大肠杆菌K88导致肠道组织中iNOS和TLR4的上调。结果表明,肠炎宁对猪大肠杆菌肠道感染具有良好的治疗作用,本试验结果为肠炎宁应用于兽医临床提供了数据支持。

In order to evaluate the protective effect of the traditional Chinese medicine Changyanning on swine enterotoxigenic Escherichia coli(ETEC)infection in mice intestine and explore its underlying mechanism,this study randomly divided SPF BALB/c mice into three groups:control group,ETEC K88 group,and Changyanning group.Mice in the ETEC K88 group and Changyanning group were infected with ETEC K88 to establish diarrhea model by gavage,and then they were orally treated with saline or Changyanning solution for three consecutive days from 12 hours post infection.Changes in survival time,body weight,intestinal histopathology,colon length,intestinal permeability,inflammatory factors,and expressions of inflammatory factor signaling pathway proteins in mice from different groups were detected.The results showed that compared with the control group,mice in the ETEC K88 group exhibited increased mortality with significantly shortened survival time(P<0.05),decreased body weight(P<0.05),shortened colon length(P<0.05),increased intestinal permeability and serum myeloperoxidase(MPO)activity(P<0.05),and elevated TNF-αand IL-1βlevels in serum and colon tissue(P<0.05).Compared with the ETEC K88 group,mice in the Changyanning group showed prolonged survival time(P<0.05),increased body weight(P<0.05),elongated colon length(P<0.05),decreased intestinal permeability and serum MPO activity(P<0.05),and decreased TNF-αand IL-1βlevels in serum and colon tissue(P<0.05).Histopathological observations revealed that Changyanning alleviated the enlargement of colonic goblet cells and inflammatory cell infiltration caused by ETEC K88 infection.Immunohistochemistry results revealed that Changyanning suppressed the upregulation of iNOS and TLR4 in intestinal tissues induced by ETEC K88.These findings suggest that Changyanning has a beneficial therapeutic effect on ETEC infection in pigs,providing experimental evidence for its application in veterinary clinical practice.