Effects Of Mankuining Prescription On Intestinal Mucosal Barrier In UC Model Mice By Regulating Intestinal Flora And SCFAs Metabolis

Objective:Mankuining is the experience of Academician Tung Chee-hwa,composed of astragalus,baishu,woody fragrance,betel nut,red peony,white peony,angelica,huanglian,huangbai,puhuang,Wulingzhi,and forsythia.In this experiment,a mouse model of UC was established using dextran sodium sulfate solution(DSS)by animal experiments,and to observe the regulatory effect of Mankuining decoction on intestinal flora-short-chain fatty acid metabolism and intestinal mucosal barrier in UC mice.Method:A total of 40 male C57BL/6 mice were randomly divided into normal group,model group,Mankuining group and mesalazine group,with 10 mice in each group.The mice in the normal group ate normally,and the mice in the other groups were fed normally,and the UC model was established after 7 days of molding.The mice in the treatment group were given the same volume of chronic sultanin and mesalamine gavage on the day of modeling,and at the same time,the normal group and model group mice were treated with the same volume of normal saline gavage once a day for 7 days.The weight and general condition of the mice were recorded daily during the experiment,and they were scored on the Disease Activity Index(DAI).On day 8,mice were sacrificed and materials were taken,colon length was recorded,feces and colon tissue were collected;Hematoxylin-eosin staining observed the histopathological changes of the colon of mice in each group,and the changes of intestinal flora and short-chain fatty acids were detected by 16SrRNA sequencing technology and gas chromatography.Immunohistochemistry detected the expression levels of MUC2 and TFF3,Western blot detected the expression of ZO-1,Occludin,Claudin-1 and Claudin-2 proteins,and real-time quantitative PCR detected the expression of MUC2,TFF3,ZO-1,Occludin,Claudin-1,Claudin-2 and mRNA.Result:Compared with the normal group,the model group had significant weight loss(P<0.01),increased DAI score(P<0.01),shortened colon(P<0.01),and severely damaged colonic mucosal structure.The content of short-chain fatty acids(SCFAs)and the total amount of intestinal SCFAs decreased significantly(P<0.01).The species abundance and diversity of intestinal flora decreased,the species abundance of Firmicutes and Actinomycetes decreased,while the species abundance of Bacteroides and Proteomycetes increased.The abundance of flora of Rhamella,Trichobacterium nk4A136,Rumen UCG-014,AKK and Lactobacillus decreased and the abundance of Staphylococcus,Bacteroides,and Shigella coli increased.Compared with the model group,the trend of weight loss slowed down(P<0.01),DAI score decreased(P<0.01),colon lengthened(P<0.01),and mucosal damage was reduced.The content of short-chain fatty acids(SCFAs)and the total amount of intestinal SCFAs increased significantly(P<0.01).The abundance and diversity of intestinal flora were restored,the species abundance of Firmicutes and Actinomycetes increased,while the species abundance of Bacteroides and Proteomycetes decreased.The abundance of Murobacter,Tricholoma nk4A136,rumen UCG-014,Lactobacillus and AKK is increasing,while the abundance of bacteroides,staphylococcus and Shigella coli is decreasing.Compared with the normal group,the expression of Occludin,Claudin-1,ZO-1,MUC2 and TFF3 proteins and mRNA in the model group was significantly reduced(P<0.01),and the expression of Claudin-2 protein and mRNA was significantly increased(P<0.01).Compared with the model group,the expression of Occludin,Claudin-1,ZO-1,MUC2 and TFF3 proteins and mRNA was increased in the Mankuining group and the mesalamine group(P<0.01),while the expression of Claudin-2 protein and mRNA was significantly reduced(P<0.01).Conclusion:(1)UC model mice will have obvious intestinal flora imbalance and intestinal mucosal barrier dysfunction,etc.,Mankuining decoction can regulate the intestinal flora of UC mice,inhibit the growth of Pathogenic bacteria,improve the abundance of Probiotics,and increase the content of SCFAs in the intestine;(2)Mankuining decoction can upregulate the expression of UC mice’s colonic mucosa-associated tight junction Proteins Occludin,Claudin-1,ZO-1 and mucus layer MUC2 and TFF3 Proteins,reduce the expression of Claudin-2 Protein,thereby exerting a Protective effect on the mechanical barrier of the intestinal mucosa and enhancing the function of the mucosal barrier;(3)As a bridge between the intestinal flora and the intestinal mucosal barrier,the increase of SCFAs has Positive significance for the Protection of the intestinal mucosal barrier function,and the role of the Mankuining decoction in Protecting the intestinal mucosal barrier may be achieved by regulating the intestinal flora and increasing the content of SCFAs in the colon.