Daurisoline alleviated experimental colitis in vivo and in vitro: Involvement of NF-κB and Wnt/β-Catenin pathway

Abstract

Daurisoline (DS) is one of the most abundant alkaloids extracted from the rhizome of Menispermum Dauricum DC, which is traditionally used to treat inflammatory diseases, especially intestinal inflammation. In this study, we established lipopolysaccharide (LPS)-induced RAW 264.7 macrophages in vitro and Dextran sulfate sodium (DSS)-induced colitis mice model in vivo to investigate the anti-inflammatory effect of DS and its underlying mechanisms. Disease activity index (DAI) was detected during drug intervention. The colon length, macroscopic changes and histopathological scores were adopted to observe the physiological status and the colon injury. The apoptosis of intestinal mucosa was detected using TUNEL. In addition, involved molecular indicators were measured by ELISA kits, RT-qPCR, immunofluorescence (IF), immunohistochemistry (IHC) and western blotting. The vitro experiments indicated that DS significantly suppressed the production of Nitric oxide (NO), reactive oxygen species (ROS) and glutathione (GSH), as well as inhibited the expression of NF-κB signaling pathway in RAW 264.7 cells induced by LPS. Consistent with the vitro experimental results, different doses of DS significantly reduced the incidence of diarrhea, DAI, shortening of the colon, visible damage and histological damage in DSS-induced colitis mice. Moreover, DS treatment decreased the levels of pro-inflammatory mediators cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) and interleukin (IL)-1β, and increased the anti-inflammatory cytokines IL-4 and IL-10 in colon tissues. RT-qPCR, western blotting and immunofluorescence analyses further demonstrated that DS inhibits the expression of Wnt/β-Catenin pathway. We reported for the first time that DS may be an active ingredient in treating ulcerative colitis. Its mechanism might be related to the regulation of the NF-κB and Wnt/β-Catenin signaling pathway.

Keywords: Daurisoline; NF-κB signaling pathway; RAW 264.7 cells; Ulcerative colitis; Wnt/β-Catenin signaling pathway.