Effect And Mechanisms Of The Butyl Alcohol Extract Of Baitouweng Decoction In Treatment Of Ulcerative Colitis Based On Regulation Of Neutrophils

Purpose:To investigate the effects and mechanisms of the Butyl Alcohol Extract of Baitouweng Decoction on ulcerative colitis in mice from the perspective of regulating neutrophils.Method:1.After adapting to the environment for one week,mice were given free access to 3%DSS solution prepared fresh daily for seven consecutive days to establish the ulcerative colitis model in mice.After successful modeling,the high,medium,and low doses of BAEB were selected according to the results of pre-experiments,and the mice were orally gavaged with 80mg,40mg,and 20mg per kg of body weight respectively.2.To observe the daily food intake,body weight,stool shape,rectal bleeding situation,and the mortality rate of each group of mice,and conduct DAI score.The colonic tissue of mice was stained with HE for pathological changes and the colon mucosal damage index(CMDI)score.Oral gavage of FITC-dextran was used to observe changes in colonic mucosal permeability.ELISA was used to detect the expression levels of pro-inflammatory cytokines IL-1β,IL-6,TNF-α,anti-inflammatory cytokines IL-4 and IL-10in mouse serum and colonic tissue.3.The effect of BAEB on the extracellular trap formation of neutrophils:ELISA was used to detect the expression levels of neutrophil chemokines CXCL1,CXCL2 in serum,colonic tissue and feces,and the expression of MPO,ELANE,MMP-8,MMP-9 in colon tissue was detected by immunohistochemistry.Western blot was used to detect the expression changes of PAD4,Cit H3,and MPO in colon tissue.4.All data should be analyzed using the SPSS 23.0 statistical software.Continuous variable data that conforms to a normal distribution should be represented as x~—±s.For comparisons between groups of data,the one-way ANOVA and least significant difference(LSD)method should be used,with P<0.05 indicating statistical significance.Results:1.BAEB could significantly improve the damage degree of intestinal tract in mice with ulcerative colitis,improve colon mucosal permeability,reduce DAI,CMDI and histopathological scores,restore weight and colon length,and have significant therapeutic effects on mice with ulcerative colitis.2.The BAEB treatment group showed a significant decrease in IL-1β,IL-6,and TNF-αlevels in both the high and medium dosage groups(P<0.05,P<0.01),while there was no difference in the low dosage group compared to the model group.The effect of the Mes group was between that of the BAEB medium and low dosage groups.The levels of the anti-inflammatory cytokine IL-4 increased in the colon tissue of mice in all BAEB treatment groups and the Mes group,with the high dosage group showing a significant effect(P<0.05).The Mes group had similar effects as the BAEB medium and low dosage groups,and there was no difference compared to the normal group.The IL-10 level increased in the high dosage group of BAEB treatment(P<0.01)and was significantly higher than the normal group(P<0.01).BAEB can reduce the expression of pro-inflammatory cytokines IL-1β,IL-6,and TNF-αin the serum and colon tissue of mice with ulcerative colitis,and restore the expression of anti-inflammatory cytokines IL-4 and IL-10.3.The levels of CXCL1 and CXCL2 decreased in the colon tissue of mice in all BAEB treatment groups,with a significant decrease in the high and medium dosage groups(P<0.05,P<0.01).There was no significant difference in the low dosage group,model group,and Mes group.BAEB can inhibit the expression of neutrophil chemokines in the serum and colon tissue of mice with ulcerative colitis,and reduce the infiltration of neutrophils in the intestinal tissue,exerting an anti-inflammatory effect.4.The expression of MPO,ELANE,MMP-8,and MMP-9 in the colon tissue decreased in the high and medium dosage groups of BAEB treatment(P<0.05).The expression levels of PAD4,Cit H3,and MPO in the colon tissue decreased,with a significant decrease in the high dosage group(P<0.01).The content of MPO,ELANE,MMP-8,and MMP-9 in the feces significantly decreased in both the high and medium dosage groups of BAEB treatment(P<0.05,P<0.01).There was no significant difference in the low dosage group and Mes group.Conclusion:After treatment with BAEB,there is a significant improvement in disease manifestation of DSS-induced colitis in mice,a decrease in the expression of pro-inflammatory cytokines and the restoration of anti-inflammatory cytokine expression,and a suppression of inflammation.It reduces the expression of PMN chemotactic factors and regulates PMN infiltration.It also decreases the expression of key proteins involved in the formation of NET in colonic tissue and reduces the levels of NET granular proteins in both colonic tissue and feces.The therapeutic effect of BAEB on DSS-induced colitis in mice may be related to the inhibition of neutrophil activity in colonic tissue and the suppression of the release of neutrophil extracellular traps.