| OBJECTIVE:The purpose of this study was to explore the mechanism of the effect of the main active component of Jiawei Gegen Qinlian Decoction(GQD)on intestinal mucosal barrier in rats with Ulcerative colitis(UC)from five aspects: intestinal mucosal barrier,chemical barrier,immune barrier,microbial barrier and metabonomics.METHODS: 1.To study the effects of GQD on intestinal mucosal mechanical,chemical and immune screen barrier in two kinds of UC rats: In this experiment,we established a common UC rat model and a damp-heat syndrome UC rat model.In addition to the blank control group(WS),ordinary UC rats were induced with 5% Dextran sulfate sodium(5%DSS)for 7 days,and they were randomly divided into model group(DS),GQD high dose treatment group(DG1,179.92 mg/kg)and GQD low dose treatment group(DG2,89.96 mg/kg).On the basis of the damp-heat pathogenic environment of "high-sugar and high-fat diet + high-temperature and high-humidity",The other 4 groups were mediated by 5% DSS for 7 days,except high-dose GQD control group(HG1,179.92 mg/kg).UC rats with damp-heat syndrome were randomly divided into model group(HD)and mesalazine treatment group(HDMS,360mg/kg)GQD high dose treatment group(HDG1179.92 mg/kg),low dose treatment group(HDG2,89.96mg/kg).In this study,GQD was used to interfere with ordinary UC rats and UC rats with damp-heat syndrome.The changes of mental state,diet,anal temperature and disease activity index(DAI)of rats were recorded,and the changes of serum biochemical indexes were detected.The effect of GQD on intestinal mucosal chemical barrier of two kinds of UC rats was studied by HE staining and oxygenase determination.The activities of D-Lactate in serum and tight junction protein ZO-1 in colon and cytokines IL-1 β,IL-6,IL-10,IL-17 A,IFN-γ,TNF-α,MIP-1 α,MIP1 β and CXCL1 were measured by Enzyme-Linked Immunosorbent Assays(ELISA).The mechanical and immune barriers of colonic mucosa were evaluated.2.To study the effects of GQD on intestinal mucosal microbial barrier and colonic metabolism in two kinds of UC rats: According to the results of the previous test,high dose GQD was selected as the therapeutic dose for this experiment.SD rats were divided into blank control group,ordinary UC model group(DS)and its treatment group(DG),damp-heat UC model group(HD)and treatment group(HDG).Model were consistent with the above,and the colonic contents and liver tissue of rats were collected.To study the changes of colonic mucosal microbial barrier by identifying rat colonic intestinal flora by 16 Sr RNA technique.The changes of short-chain fatty acids(SCFA)and medium-long-chain fatty acids(M-LCFA)in colonic contents were detected by targeted metabonomics GC-MS technique.Amino acid(AA)changes in rat colonic contents were quantitatively detected by HPLC,and bile acid(BA)changes in rat liver were detected by LCMS.The results are as follows:RESULT: 1.The model group accorded with the standard of ulcerative colitis(damp-heat syndrome).According to the clinical symptoms and macroscopic and microscopic pathological changes of colon,two kinds of ulcerative colitis models were established successfully.Compared with UC rats,the colon inflammatory injury of UC rats with damp-heat syndrome was more serious.GQD combined with puerarin,berberine,baicalein,glycyrrhizic acid and magnolol had significant curative effect on the two kinds of rats.GQD could significantly decrease the elevated levels of ALP,LDH,AST,ALT and AST/ALT in the serum of the two kinds of UC rats(P < 0.05);GQD could reduce the excessive activities of CHOL,TG,HDL-C,LDL-C and GLU in UC rats with damp-heat syndrome.GQD could decrease the levels of MDA,NO and MPO and increase the levels of SOD,GST,GSH and CAT in the colon of two kinds of UC rats.GQD could effectively decrease the levels of DAO and D-lactic acid in serum of two kinds of UC rats,increase the expression of ZO-1 and IL-10 in colon,and decrease the activities of IL-1β,IL-6,IL10,IL-17 A,IFN-γ,TNF-α,MIP-1α,MIP-1β and CXCL1 in colon tissue of rats.2.GQD decreased the abundance of Bacteroides and Escherichia coli-Shigella in the colonic flora of UC rats,and tended to increase the unclassified＿f＿Ruminococcaceae abundance of Akkermansia and verruciaceae(P > 0.05).GQD significantly increased the community abundance of Bacteroides,Megamonas,Blautia and Akkermansia in colonic microorganisms of hot and humid UC rats,and decreased the abundance of Allobaculum,Ruminococcus＿gauvreauii＿group,Lachnoclostridium and Romboutsia of verrucous microorganisms(P<0.05).GQD showed a tendency to decrease the number of Escherichia coli-Shigella(P > 0.05).Compared with DS group,GQD increased the content of Propionic acid and Butyric acid in UC rats(P<0.001),and GQD increased the content of Propionic acid in damp-heat UC rats compared with HD group(P<0.001).Compared with DS group,GQD increased the contents of methyl 24carbenoate(C24:1)and methyl antioleate(C18:1n9t)in UC rats(P<0.05).The content of methyl linoleate(C18:2n6c)in UC rats was decreased by);GQD.Compared with HD group,GQD significantly decreased the contents of methyl undecanoate(C11:0),methyl heptadecanoate(C17:0)and methyl caproate(C6:0)in colonic contents of UC rats with dampness-heat syndrome.Compared with DS group,GQD decreased the content of deoxycholic acid(DCA)in liver of Putong UC rats(P<0.05),and compared with HD group,GQD decreased the contents of taurocholic acid(T-MCA)and deoxycholic acid(DCA)in liver of UC rats with damp-heat syndrome(P<0.05).Compared with the two UC model groups,GQD had a tendency to increase the contents of branched chain amino acids and aromatic amino acids in the colonic contents of the two kinds of UC rats,but the difference was not statistically significant(P>0.05).CONCLUSION: 1.We successfully used DSS to induce UC symptoms in rats,and the damp-heat UC rat model was successfully established by using the compound factors of "high temperature and humidity + high sugar and high fat + wine + DSS".2.DSS could causes excessive activation of oxidative stress and immune response in rats,and reduces the richness and diversity of intestinal flora,causes metabolic disorders such as SCFA,M-LCFA,AA and BA,and caused colonic mucosal damage,which is aggravated by damp-heat syndrome UC on the basis of DSS.3.GQD has preventive and therapeutic effect on these two UC models and increases in a dose-dependent manner.4.The protective effects of GQD on UC and damp-heat UC rats may be related to improving hyperlipidemia,restoring liver function,improving antioxidant capacity,strengthening intestinal tight junction,inhibiting the expression of intestinal proinflammatory factors,regulating intestinal flora,restoring colonic microflora,increasing the content of SCFAs,regulating M-LCFAs,maintaining BAs homeostasis,regulating AA metabolism and improving colonic permeability.It is related to promoting the healing of intestinal mucosa.Therefore,GQD is expected to become a promising anti-ulcerative colitis drug. |
