Mechanism Of Electroacupuncture On Relieving Colitis By Regulating Cannabinoid Receptor 1

Objective: A few studies have found that electroacupuncture can relieve the dextran sodium sulfate(DSS)-induced colitis through unknown mechanisms.Cannabinoid receptor 1(CB1)was shown to play an important part in the protection of the intestinal inflammation in recent studies.Gut microbiota can influence the expression of CB1.Therefore,the purpose of this study is to evaluate whether electroacupuncture can regulate CB1 by affecting intestinal flora,thus alleviating colitis.Methods: C57BL/6 mice were randomly divided into control group,DSS group,DSS with sham electroacupuncture group,DSS with low-frequency electroacupuncture group,and DSS with high-frequency electroacupuncture group.Except for the control group,the mice were given 3% DSS for 7 days to induce acute colitis model.The body weight and stool characteristics were monitored every day.On the 8th day,the mice were sacrificed.The feces of mice were collected for microbial detection and preparation of fecal bacteria suspension,and the colon tissues of mice were collected for subsequent experiments.The disease activity index score,colon length,histological score,and inflammatory factors were detected to evaluate colonic inflammation.Methods for detecting intestinal barrier functions included the expression of tight junction proteins,intestinal permeability,and the number of goblet cells.Moreover,the number of autophagosomes and autophagy-related proteins were detected to evaluate the level of autophagy.Polymerase Chain Reaction and Western blot were performed to assess the levels of CB1.16 S r RNA sequencing was applied to analyze alterations in the gut microbiota.On the basis of acute colitis model,the mice model of CB1 antagonism was induced by administration of CB1 antagonist and the mice model of fecal bacteria transplantation was induced by administration of fecal bacteria suspension.In these models,the same methods were used to evaluate the CB1 expression,autophagy level,intestinal barrier,and intestinal inflammation.Results: Electroacupuncture reduced the disease activity index score,restored the colon length,decreased the histological score,and the levels of inflammatory factors in mice with colitis.Moreover,electroacupuncture increased the expression of tight junction proteins and the number of goblet cells,and decreased intestinal permeability.In addition,electroacupuncture enhanced the intensity of autophagy,and upregulated the levels of CB1 in mice with colitis.Moreover,electroacupuncture remodeled the community structure of the gut microbiota,and regulated the abundance of bacteria.However,after antagonizing CB1,the effects of inflammatory relief,intestinal barrier integrity,and enhancing autophagy were weakened,suggesting the important role of CB1 in the electroacupuncture.Fecal bacteria transplantation experiment also found the up-regulated level of CB1,enhanced level of autophagy,repaired intestinal barrier,and alleviated colitis in mice with the administration of bacterial from the mice after electroacupuncture,implying that electroacupuncture can regulate the expression of CB1 by affecting the intestinal flora.Conclusions: Electroacupuncture may increase the levels of CB1 to enhance the autophagy by affecting the gut mictobiota,thus repairing the intestinal barrier and alleviating the intestinal inflammation in DSS-induced acute colitis.