Gentianine alleviates dextran sulfate sodium-induced ulcerative colitis via inhibition of TLR4/NLRP3-mediated pyroptosis

Objectives: Ulcerative colitis (UC) is a common inflammatory bowel disorder. Gentiana scabra Bunge is a traditional medicinal plant that is used to treat a variety of diseases. Studies have shown that gentianine (GTN) from Gentiana scabra inhibits the development of inflammatory diseases. The purpose of this study was to investigate the effect and possible mechanism of action of GTN on UC in mice. Methods: An animal model of UC was established using dextran sulfate sodium (DSS). Mice were administered intraperitoneally with GTN (12.5, 25, or 50 mg/kg/day) for seven days. Body weight and disease activity index (DAI) were monitored daily during GTN administration. Colon length, pathological changes, and myeloperoxidase (MPO) activity were measured following GTN administration. The signalling pathways regulated by GTN were analysed using machine learning. HT-29 cells were used to verify the effect and mechanism of action of GTN on UC in vitro. Results: GTN suppressed weight loss, shortened colon length, alleviated colon injury, and reduced the DAI score and MPO activity of mice with UC in a dose-dependent manner. Further analysis showed that GTN inhibited the NOD-like receptor (NLR) signalling pathway. GTN markedly decreased the levels of NLR signalling pathwayrelated proteins. Moreover, GTN decreased the levels of pyroptosis-related proteins, IL-1 beta and IL-18. The in vitro data were consistent with those of animal experiments. Furthermore, TLR4 and NLRP3 overexpression eliminated the protective effects of GTN in HT-29 cells. Conclusion: Gentianine alleviated DSS-induced UC by inhibiting TLR4/NLRP3-mediated pyroptosis.