# Tibetan Fritillaria cirrhosa D. Don Extract Ameliorates DSS-Induced Ulcerative Colitis by Repairing Damage to the Intestinal Mucosal Barrier and Regulating the Gut Microbiota

## TL;DR

Tibetan Fritillaria cirrhosa extract helps treat ulcerative colitis in mice by repairing the gut lining and balancing gut bacteria.

## Contribution

The study shows FCD extract's novel therapeutic potential for UC through mucosal repair and microbiota modulation.

## Key findings

- FCD reduced colon shortening and disease activity in DSS-induced colitis mice.
- FCD enhanced intestinal barrier proteins like ZO-1 and occludin and increased IL-10 levels.
- FCD promoted gut microbiota diversity and reduced pro-inflammatory cytokines.

## Abstract

Background/Objectives: Ulcerative Colitis (UC) is a chronic inflammatory disease of the colon that profoundly impacts human health. Conventional pharmacological treatments are associated with serious adverse reactions and toxic side effects. Consequently, the development of natural plant-derived biological agents for UC treatment is an urgent imperative. Methods: Utilising a Dextran Sulfate Sodium (DSS)-induced ulcerative colitis mouse model, with mice receiving low, medium, and high doses of water extract of Tibetan Fritillaria cirrhosa D. Don extract (FCD), alongside a group receiving 5-aminosalicylic acid. The Disease Activity Index (DAI) was calculated, colon length was measured, histological scores were assessed, and histopathological alterations were evaluated. Inflammatory factor were determined by ELISA; mRNA and protein expression in colonic tissue was analysed by RT-qPCR and Western blotting; intestinal barrier-related proteins were examined by immunofluorescence and immunohistochemistry; and gut microbiota composition was assessed by 16S rRNA sequencing. Results: Research has confirmed that FCD alleviates symptoms of DSS-induced colitis in mice, specifically manifested by a slower rate of weight loss, reduced colon shortening, and decreased disease activity index. It has been demonstrated that the process under investigation exerts a beneficial effect on intestinal injury by means of a number of mechanisms. These include increased goblet-cell production, elevated IL-10 levels, and reduced levels of TNF-α, IL-1β, and IL-6. Furthermore, immunofluorescence detection, immunohistochemical analysis, and RT-qPCR results indicate that FCD maintains the integrity of the intestinal mucosal barrier by enhancing the expression of Zonula occludens-1 (ZO-1), occludin, and claudin-1 proteins and their corresponding mRNAs, in addition, FCD can regulate the gut microbiota and promote its diversity. Conclusions: Research indicates that FCD may exert therapeutic effects on ulcerative colitis (UC) by regulating intestinal barrier integrity and modulating the gut microbiota. These findings reinforce the idea that FCD could be used as a natural therapy to improve UC.