| Inflammatory bowel disease(IBD) is a group of chronic inflammatory gastrointestinal disorders of unknown etiology, and is not medically curable. Efficient and safe drugs for its treatment is a critical unmet need. Hericeum erinaceus is an important mushroom with edible values and medicinal properties, which contains lots of bioactive compounds. It can be used for the treatment of a variety of diseases, including indigestion, gastric ulcer, duodenal ulcer, neurasthenia and so on. The aim of this study was to evaluate the anti-inflammatory activity of extracts of H.Erinaceus by using DSS-induced colitis in mice, investigate the anti-inflammatory mechanism, and provide the theoretical basis for the treatment of IBD.Firstly, crude polysaccharide from H. erinaceus(HECP) and ethanol extract from H. erinaceus(HEEE) were prepared, and the yield was 27.10% and 43.01%, respectively. HECP contained 57.81% polysaccharide constituent and 10% protein constituent, as well as seven kinds of monosaccharide such as glucose(48.04%) and galactose(9.72%) after hydrolysis of polysaccharide. HEEE contained 31% fat constituent, including lots of unsaturated fatty acids and essential fatty acids.Then, we eatablished the animal colitis model by exposing mice in 2% DSS in their drinking water for 7 days. Meanwhile, HEEE and HECP were administrated(250 mg/kg/d and 500 mg/kg/d) to evaluate their pharmaceutical values. The results showed that administration of HECP and HEEE could both significantly increase body weight and colon length(19.24%‐33.21%), decrease the intestinal bleeding and MPO levels(2-3 folds) induced by DSS. They also reduced the histological severity in mice by a protective role of neutrophils and lymphocytes infiltration, crypt damage and ulceration of mucosal epithelium. In addition, they ameliorated colitis not only by suppressing the production of inflammatory mediators including TNF-α, IL-1β and IL-6 in the colonic tissues, but also adjusting the production of NO, MDA and SOD in serum to repair the oxidative damage of mucosal barrier.In order to clarify the anti-colitis mechanism of HECP and HEEE, an in vitro cell model was designed by using a murine macrophage-like cell line RAW264.7 stimulated by lipopolysaccharide(LPS) to investigate the anti-inflammatory mechanism of HECP and HEEE. We found that HEEE could inhibit NO generation induced by LPS in a dosage-dependent manner. Meanwhile, HEEE could effectively be anti-inflammatory by decreasing the secrection of IL-1β.Furthermore, we investigated the anti-colitis mechanism by using PCR-DGGE technology to examine the shifts in gut microbiota which is important for induction of IBD. The results showed that the gut microbiota was disturbed in DSS-induced colitis. The abundance of C. cocleatum was decreased, A. muciniphila and B. intestinihominis was increased otherwise. While the administration of HECP suppressed the trendency of changes resulted from DSS. In addition, high-throughout prosequencing technique was employed to investigate the effects of HECP on microbiota diversity and composition of colon in mice. Findings showed that the diversity of bacteria was markedly decresed in DSS-induced colitis. Proportion of Firmicutes and Bacteroidetes which were dominating microbial species in control mice was decreased by 3.31% and 46.78%, respectively. Proteobacteria was increased up to 20.47%. HECP could increase Firmicutes, decrease Proteobacteria and improve the diversity. Thus, HECP could maintain and protect the microbial diversity disturbed by DSS.In conclusion, this paper indicated that HECP and HEEE had therapeutic effect on DSS-induced colitis in mice by increasing blood anti-oxidant capacity and by down-regulation of the expression of inflammatory mediators. In addition, HECP could improve the diversity of intestinal flora and maintain steady enviroment of gut to ameliorate IBD. |
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