The Study On Prevention Mechanism Of Si Jun Zi Tang On E.coli-induced Diarrhea Of Mice

The aim of this paper was to clarify the prevention and cure mechanism of sijunzitang on E.coli-induced diarrhea. Methods:Mice were devided into Prevention group, treatment group, self-healing group and Control group. Infected mice were Intraperitoneal injection 2.6 billion E.coli O101 to build Diarrhea model. Prevention group mice were lavaged with sijunzitang 5 days in advance,after build model keep lavaging with 0.5ml sijunzitang in the morning and evening. Treatment group mice were lavaged with 0.5ml sijunzitang in the morning and evening. Self-healing group mice were to build model with e.coli only. Control group mice were lavaged with Saline. Everyday the clinical symptoms were observed and selected 3 mice for autopsy in each group. The changes of Histopathological and Ultrastructure were observed by the Conventional slicing and Electron microscopy methods, the expression of mucosal repair gene were analysised by the Immunohistochemistry and PCR methods.The results as follow:Clinical symptoms: self-healing group, the treatment group and the prevention group appeard the Diarrhea after Infection 8 hours, mice gloomy spirit, fatigue, reduced food intake, hair reverse lap, abdominal breathing, yellow excretion, the eyelids swelling and secretion increase, 96h later, the symptoms gradually improved and recovery; treatment groups mice had the same symptoms, but the incidence was slightly decreased; prevention group mice symptoms decreased and the number of diarrhea mice was reduced, the restoration time was significantly reduced; control group mice had any clinical symptoms.Autopsy changes: after Infect, the mice liver, kidney, spleen swelled, duodenal have scattered bleeding points, intestinal wall became thiner, intestine tract was full of yellow thin contents, gall bladder was full of bile, Stomach flatulence severely; The treatment group had the similar changes, but the repair time was reduced; The lesion of prevention group mice were decreased, and bleeding points in Duodenal were reduced, and repair time was reduced; control group mice had any visible pathological change.Histopathological changes: After Infection, the small intestine villi appeared partial ruptured, villous epithelial cell were swelled and necrosis partly, submucosa were congestion, edema and some inflammatory cell infiltration. The numbers of goblet cells were increased. The intestinal gland became degeneration obviously. The number of goblet cells did not increased significantly in treatment group, and other lesions consistent with the self-healing group. in prevention group, the number of goblet cells and submucosal edema had no significant changes, after 96h the mice recovery gradually. Control group mice had the normal intestinal organizational structure.Ultrastructural Changes: under SEM, the villous were edema severely, the goblet cell had abnormal form and the number was increased. The top microvilli were swollen, necrotic, sparse and clutter. In treatment group, the ultrastructural changes were relatively better than that of self-healing group. In prevention group, ultrastructural have lighter lesions and the microvilli were in disorder. Control group, small intestinal villous and microvilli were arranged normally.By TEM observe, rough endoplasmic reticulums were expansion, many small vacuoles and pinocytotic vesicles were existed. The epithelial microvilli were disordered. Mitochondria appeared vacuolization, mitochondrial cristae and membrane disappeared. Goblet cells contain a large number of secretory granules. In the treatment group and prevention group, the changes of ultrastructural were relatively better than that of self-healing group. In control group, the small intestine epithelium microvilli arranged neatly, the mitochondrial structure were normal, and the epithelium cell were integrity.Immunohistochemistry results showed that, in the early diarrheal period, the expression of PCNA, TGFβ1 were most significantly increased in prevention group than that of the normal group, and it were significantly increased in prevention group than that of the normal group (P<0.05).The result by RT-PCR methods showed that the expression of Repair gene TGFβ1,EGFRwere most significantly increased in prevention group than that of the normal group, and it were significantly increased in treatment group and the self-healing group than that of the normal group (P<0.01) , it were significantly increased in prevention group and treatment group than that of the self-healing group (P<0.05).Conclusion: The Sijunzitang had the significantly effects in improved clinical symptoms, pathologic changes, histopathological changes and the ultrastructural pathologic changes of diarrheal mice. The sijunzitang significantly increased the expression of TGFβ1,EGFR,PCNA. The results suggest that the preventive effect of Sijunzitang on diarrhea maybe have the relationship with the upregular the expression of mucosal repair gene PCNA,EGFR,TGFβ1 and promote the damaged mucosa repaired.