Suppression of MAPK and NF-κ B pathways by schisandrin B contributes to attenuation of DSS-induced mice model of inflammatory bowel disease.

Schisandrin B (Sch B), the most abundant dibenzocyclooctadiene lignan isolated from the traditional Chinese medicinal herb Schisandra chinensis (Turcz.) Baill, possesses various biological activities, such as hepatic protection, anti-tumor, anti-inflammatory and anti-cardiovascular properties. However, the effect of Sch B on inflammatory bowel disease (IBD) is not yet known. The aim of this study was to investigate whether Sch B has protective effect against dextran sulfate sodium (DSS)-induced colitis in a mouse model. The acute mouse model of IBD was induced by drinking 2.5% DSS water for 5 days. Sch B was administered orally in doses of 10, 40, and 100 mg/kg respectively. It significantly reduced concentration of TNF-α, IL-1β, INF-γ and IL-6 in colon tissue as well as the mRNA expression levels. In addition, we demonstrated that Sch B blocked the phosphorylation of IκBα, nuclear factor-κB (NF-κB) p65, p38 mitogen-activated protein kinase (MAPK), c-Jun NH2-terminal kinase, and extracellular signal regulated kinase in DSS-induced acute colitis. In conclusion, these results indicated that Sch B could exert beneficial effects on experimental IBD induced by DSS and may represent a novel treatment strategy for IBD.