Modified Shi Hui San decoction ameliorates murine experimental colitis through multiple mechanisms.

Background: Modified Shi Hui San (MSHS) has shown excellent therapeutic effects on ulcerative colitis (UC) patients clinically in China. However, the exact mechanism underlying its effect remains unclear and needs to further investigation.

Objective: This study aimed to investigate the therapeutic effects of modified Shi Hui San decoction (MSHSD) in murine experimental colitis and explore its underlying mechanisms.

Methods: To examine the effects of MSHSD on UC, a murine model of colitis was induced using 2.5 % dextran sodium sulfate (DSS). The mice were then treated with MSHSD at the doses of 6.25 or 25 g/kg for 10 days. The progression of colitis was evaluated through clinical symptoms, histopathological analysis, evaluation of mucosal barrier integrity, biochemical assays, and analysis of the gut microbiota composition.

Results: MSHSD administration markedly ameliorated experimental colitis in DSS-treated mice by suppressing inflammation, restoring the intestinal mucus barrier, alleviating oxidative stress, and reestablishing immunity. More importantly, it transformed the gut microbiota structure from an imbalanced state to a normal state.

Conclusions: These findings for the first time extend our understanding of the mechanisms, by which MSHSD ameliorates murine experimental colitis, and support the clinical use of MSHS for UC treatment.