Ameliorative effect of an acid polysaccharide from Phellinus linteus on DSS induced ulcerative colitis mice

Phellinus linteus, a rare medicinal fungus, has strong anti-tumor and anti-inflammatory activities due to its active metabolites, such as polysaccharides. In this study, we investigated the effect of Phellinus linteus acid polysaccharide on the amelioration of dextran sodium sulfate induced ulcerative colitis in a mouse model and its related mechanisms. PLAP alleviated the symptoms of UC mice such as weight loss, reduced food intake, increased disease activity index, and restored histopathological damage to the colon. PLAP significantly decreased the levels of pro-inflammatory factors, increased the levels of anti-inflammatory factor IL10, and decreased the levels of oxidative stress-related enzymes. The qPCR results showed that PLAP significantly downregulated the phosphorylation levels of p65 and p38 and the transcriptional levels of TLR4. The expression of tight junction proteins was enhanced after PLAP treatment. High-throughput sequencing showed that PLAP significantly restored gut microbiota diversity and species abundance in UC mice. GC analysis showed that PLAP had the effect of increasing SCFA content. In summary, PLAP has the potential for development of anti UC agents by reducing inflammation and oxidative stress levels, modulating the composition of the gut microbiota, and restoring intestinal barrier function.