Therapeutic Efficacy and Underlying Mechanisms of a Mannoglucan from Hirsutella sinensis Mycelium on Dextran Sulfate Sodium-Induced Inflammatory Bowel Disease in Mice: Modulation of the Intestinal Barrier, Oxidative Stress and Gut Microbiota

Hirsutella sinensis (H. sinensis), a non-sexual form of the valuable Chinese medicinal herb, demonstrates various biological activities, such as immune modulation and antioxidative capabilities. Nonetheless, the effects of bioactive polysaccharides derived fromH. sinensison colitis have yet to be investigated. In our prior research, we extracted a mannoglucan (HSWP-1d) fromH. sinensisand found that it attenuates TGF-β1-induced epithelial-mesenchymal transition. The present study investigated the protective effects of HSWP-1d against colitis induced by dextran sulfate sodium (DSS) in mice. The results demonstrate that HSWP-1d effectively ameliorates symptoms of colitis and preserves the intestinal barrier’s stability by enhancing the expression of tight junction proteins. The administration of HSWP-1d results in a reduction in oxidative stress through the augmentation of antioxidative enzyme activities, concomitant with the suppression of oxidative product generation. Simultaneously, HSWP-1d reduced the levels of pro-inflammatory cytokines while elevating the levels of anti-inflammatory cytokines, effectively mitigating the inflammatory response. Furthermore, HSWP-1d influences and alters short-chain-fatty-acid (SCFA) levels, thereby enhancing the intestinal microenvironment. In conclusion, HSWP-1d contributes to intestinal well-being and holds potential as both a therapeutic choice and a supplier of essential nutrients for the amelioration of colitis.