Effect of Coptis chinensis franch and Magnolia officinalis on intestinal flora and intestinal barrier in a TNBS-induced ulcerative colitis rats model

In folk medicine Coptis chinensis Franch (Huanglian in Chinese, HL) and Magnoliae officinalis (Houpo, HP) have been used to treat gastrointestinal disorders over hundreds of years, such as ulcers and inflammation.To investigate the therapeutic effects of HL and HP on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced ulcerative colitis (UC) rats, and investigated its effect on the intestinal flora of UC rats.TNBS 40 mg/kg was utilized to establish UC model. Rats were sacrificed after gavage for 7 days. Body weight loss, disease activity index (DAI), colonic mucosal damage index (CMDI) and histopathology were measured. Intestinal content samples were collected, and analyzed by 16 S rRNA sequencing. Western blot, immunohistochemistry and real-time polymerase chain reaction were used to evaluate the regulation mechanism of HL+HP in UC model rats.The results showed that the DAI score, CMDI score and histological score were significantly decreased in each group. The symptoms of diarrhea, hematochezia, colonic mucosal injury and congestion and edema were improved. Sequencing results of intestinal flora showed that the abundance of probiotics such as Akkermansia and Blautia was increased in HL group and HL+HP group, while probiotics such as Allobaculum and Alloprevotella were increased in HP group. The intestinal pathogenic bacteria such as Escherichia-Shigella and Clostridium_sensu_stricto_1 were decreased. In addition, HL+HP could also inhibit the inflammatory response and protect the integrity of the tight junction to play an anti-UC effect.Coptis chinensis Franch and Magnolia officinalis might prevent intestinal barrier damage by regulating intestinal flora imbalance and inhibit the inflammatory response.