Anti-Inflammatory Effects of Heritiera littoralis Fruits on Dextran Sulfate Sodium- (DSS-) Induced Ulcerative Colitis in Mice by Regulating Gut Microbiota and Suppressing NF-κB Pathway

Aim of the Study. This study is aimed at exploring the effects and pharmacological mechanisms of the extracts from the Heritiera littoralis fruit (EFH) on dextran sulfate sodium- (DSS-) induced ulcerative colitis (UC) in mice. Materials and Methods. The chemical compositions of EFH were identified using LC-ESI-MS. The mice with 3% DSS-induced UC were administered EFH (200, 400, and 800 mg/kg), sulfasalazine (SASP, 200 mg/kg), and azathioprine (AZA, 13 mg/kg) for 10 days via daily gavage. The colonic inflammation was evaluated by the disease activity index (DAI), colonic length, histological scores, and levels of inflammatory mediators. The gut microbiota was characterized by 16S rRNA gene sequencing and analysis. Results. LC-ESI-MS analysis showed that EFH was rich in alkaloids and flavones. The results indicated that EFH significantly improved the DAI score, relieved colon shortening, and repaired pathological colonic variations in colitis. In addition, proteins in the NF-kappa B pathway were significantly inhibited by EFH. Furthermore, EFH recovered the diversity and balance of the gut microbiota. Conclusions. EFH has protective effects against DSS-induced colitis by keeping the balance of the gut microbiota and suppressing the NF-kappa B pathway.