Ulcerative colitis (UC), one of the typical inflammatory bowel diseases caused by dysregulated immunity, still requires novel therapeutic medicine with high efficacy and low toxicity. Hericium erinaceus has been widely used to treat different health problems especially gastrointestinal sickness in China for thousands of years. Here, we isolated, purified, and characterized a novel low weight polysaccharide (HEP10, Mw: 9.9 kDa) from the mycelia of H. erinaceus in submerged culture. We explored the therapeutic effect of HEP10 on UC and explored its underlying mechanisms. On one hand, HEP10 suppressed the production of TNF-α, IL-1β, IL-6, inducible iNOS, and COX-2 in LPS challenged murine macrophage RAW264.7 cells, as well as in colons from DSS-induced colitis mice. On the other hand, HEP10 treatment markedly suppressed the activation of NLRP3 inflammasome, NF-κB, AKT, and MAPK pathways. Moreover, HEP10 reversed DSS-induced alternation of the gut community composition and structure by significantly increasing Akkermansia muciniphila and also promoting functional shifts in gut microbiota. Structural equation modeling also highlighted that HEP10 can change widely through gut microbiota. In conclusion, HEP10 has a better prebiotic effect than the crude polysaccharides of H. erinaceus, which can be used as a novel dietary supplement and prebiotic to ameliorate colitis.

Background: The imbalance of Treg/Thl7 cells and inflammatory injury are believed to be involved in the development of ulcerative colitis (UC). Meanwhile, 6-gingerol has been reported to alleviate intestinal inflammatory damage in mice models, but the underlying mechanism remains elusive. Methods: In this study, dextran sulfate sodium (DSS)-induced colitis mice models were established to examine the effects of 6-gingerol on IL-17 and IL-10 secretion, and the activation of NF-κB signaling was evaluated using enzyme-linked immunosorbent assay (ELISA), Western blotting, and immunohistochemistry. Results: 6-gingerol could significantly reduce the weight loss caused by DSS in mice models (P<0.05), which is similar to the therapeutic drug, mesalazine. Immunohistochemistry showed that 6-gingerol can repair the damaged glandular structure gradually caused by DSS, significantly decrease the IL-17 level, and increase IL-10 level in bowel tissue. ELISA revealed that 6-gingerol could significantly decrease the IL-17 level and increase IL-10 level in both serum and bowel tissue, and the differences were all statistically significant (P<0.05). In addition, 6-gingerol could suppress the phosphorylation level of IκBα and p65, which was up-regulated by DSS. Further analysis with immunohistochemistry indicated p-p65 staining was mainly in the nucleus with some in the cytoplasm after DSS treatment, and the treatment with 6-gingerol could significantly weaken the density of p-p65 both in the cytoplasm and nucleus. Conclusions: Our study suggests that 6-gingerol may alleviate inflammatory injury in UC mice by regulating NF-κB signaling pathway.