Mechanism of Tongxie yaofang reducing colon hypermotility in IBS-D rats by regulating gut microbiota-ENS-MM crosstalk / 中国药房

ABSTRACT

OBJECTIVE To study the effects of Tongxie yaofang reducing colon hypermotility in irritable bowel syndrome with diarrhea （IBS-D） rats by regulating gut microbiota-enteric nervous system （ENS）-muscularis macrophages （MM） crosstalk. METHODS Forty newborn male SD rats were randomly divided into control group， model group， TCM group [Tongxie yaofang 2.68 g/（kg·d）， calculated by raw material]， and positive control group [Live combined bifidobacterium and lactobacillus tablets 0.27 g/（kg·d）]， with 10 rats in each group. Except for the control group， the IBS-D model of liver stagnation and spleen deficiency syndrome was induced in the other 3 groups with the method of mother-child separation+chronic restraint+Folium Sennae- induced diarrhea. After modeling， the administration groups were given relevant drug liquid intragastrically， once a day， for consecutive 2 weeks. At the end of modeling and after administration， the fecal properties （the incidence and the rate of loose stools）， colonic motility （colon emptying time）， and visceral sensitivity [abdominal withdrawal reflex （AWR） scores under different pressures] of rats were observed in each group. The concentration of lipopolysaccharide （LPS） in serum was detected after medication， and the expressions and distribution of bone morphogenetic protein 2 （BMP2）， colony stimulating factor 1 （CSF1） and Toll-like receptor 4 （TLR4） in colon tissue were detected； the diversity， species composition and differences of gut microbiota were also determined. RESULTS At the end of modeling， compared with the control group， all rats of the other three groups suffered from loose stools （100%）， the rate of loose stools and AWR scores at different pressures increased significantly， and colon emptying time was shortened significantly （P＜0.01 or P＜0.05）. The incidences of loose stools were 20% in TCM group and 80% in the positive control group； the rate of loose stools and AWR scores at different pressures， serum concentration of LPS and protein expressions of CSF1 and TLR4 in muscle layer of colon tissue in TCM group significantly decreased， compared with the model group； colon emptying time， the average optical density of BMP2 protein in muscle layer of colon tissue， and the indexes of Chao 1， Shannon and Faith’s PD and Simpson E-mail：772699670@qq.com index of rats in TCM group were all prolonged or increased significantly， compared with the model group （P＜0.01 or P＜ E-mail：aiwangzi312@163.com 0.05）. The relative abundance ratio of Firmicutes/Bacteroidetes， from low to high， was in the order of TCM group， control group， positive control group and model group； the species composition of gut microbiota in TCM group was closer to control group， with dominant bacterial genera including Prevotella and Blautia. CONCLUSIONS Tongxie yaofang can regulate the expressions of BMP2 and CSF1， the key proteins of gut microbiota-ENS-MM crosstalk， by changing the gut microbiota， thus alleviating the abnormal hyperfunction of colon motility in IBS-D rats.