Oxysophocarpine suppresses TRAF6 level to ameliorate oxidative stress and inflammatory factors secretion in mice with dextran sulphate sodium (DSS) induced-ulcerative colitis

Abstract

Purpose: Ulcerative colitis is an inflammation-related disease with a high recurrence risk. Oxysophocarpine (OSC) is a traditional Chinese medicine isolated from legumes and exerts vital functions on many human diseases. However, the OSC's role in ulcerative colitis has not been fully elucidated. This research aimed to investigate the OSC's impact on ulcerative colitis and its mechanisms.

Methods: A mouse model of ulcerative colitis was induced by dextran sulphate sodium (DSS). The effect of OSC on ulcerative colitis was examined using Disease Activity Index detection, hematoxylin-eosin (HE) staining, and enzyme-linked immunosorbent assay (ELISA). Meanwhile, the mechanism of OSC in ulcerative colitis was assessed by immunohistochemistry assay, Western blot, HE staining, and ELISA.

Results: For the OSC's function in ulcerative colitis, OSC increased the mice weight, decreased Disease Activity Index scores, and alleviated colitis cell infiltration and epithelial cell destruction in DSS-induced ulcerative colitis. Also, OSC mitigated oxidative stress (decreased PGE2, MPO levels, and increased SOD levels) and inflammation (decreased IL-6, TNF-α and IL-1β levels) in DSS-induced ulcerative colitis. For the OSC's mechanism in ulcerative colitis, OSC inhibited the level of tumor necrosis factor receptor-associated Factor 6 (TRAF6) and the phosphorylation of nuclear factor-κB (NF-κB). TRAF6 overexpression abolished the effect of OSC on DSS-induced colon injury and its associated oxidative stress and inflammatory properties in ulcerative colitis.

Conclusion: OSC decreased the TRAF6 level to reduce oxidative stress and inflammatory factors secretion in mice with DSS induced-ulcerative colitis.

Keywords: Inflammatory; Oxidative stress; Oxysophocarpine; TRAF6; Ulcerative colitis.