Rheum tanguticum polysaccharide alleviates DSS-induced ulcerative colitis and regulates intestinal microbiota in mice

Rheum tanguticum polysaccharide (RTP) was the bioactive extract of Rheum. The aim of this study was to make a preliminary structural identification of RTP and to investigate its therapeutic mechanism against colitis. In this study, we analyzed the functional groups, monosaccharide composition and molecular weight of the novel polysaccharide RTP. The disease status, oxidative stress status, inflammatory cytokine levels, expression of inflammation-related genes, and changes in the intestinal flora of mice with colitis after RTP intervention were evaluated. The data indicated that RTP is an acidic heteropolysaccharide composed of eight monosaccharides. It attenuated the pathological symptoms of colitis mice, reduced the secretion of inflammatory cytokines (IL-6, TNF-α, IL-1β) and down-regulated oxidative stress markers (MDA, MPO). Meanwhile, RTP could regulate the expression of genes related to Notch and NF-κB signaling pathways and reverse the dysregulation of intestinal microbes in colitis mice. In conclusion, RTP improved the symptoms of DSS-induced colitis in mice and has the potential to develop drugs or functional foods for the treatment of colitis.