Protective roles and mechanisms of Dendrobium officinal polysaccharides on secondary liver injury in acute colitis

The purpose of this study was to investigate the protective roles and mechanisms of Dendrobium officinale polysaccharides (DOPS) on secondary liver injury in acute colitis. Firstly, the mice model of secondary liver injury in acute colitis was induced by 4% Dextran sodium sulfate (DSS). Inflammatory cell model was established by LPS-stimulated RAW264.7 cells. Then, the protective roles of DOPS were evaluated by both in vivo and in vitro experiment. The results showed that DOPS attenuated DSS-induced hepatic pathological damage, liver parameters, infiltration of macrophages, cytokines levels, MDA level and increased the antioxidant enzymes activities. In vitro, DOPS markedly inhibited inflammatory cytokines production and increased antioxidant enzymes activities. Finally, its molecular mechanisms were also observed. The results indicated that DOPS could down-regulated TNF-α signaling pathway and activated Nrf-2 signaling pathway in vivo and in vitro. These results suggested that DOPS may be an effective therapeutic reagent to attenuate secondary liver injury in acute colitis.