Anti-inflammatory, anti-colitis, and antioxidant effects of columbianadin against DSS-induced ulcerative colitis in rats via alteration of HO-1/Nrf2 and TLR4-NF-κB signaling pathway

Background: Ulcerative colitis (UC) is a significant inflammatory bowel disease (IBD) that typically arises from chronic inflammation of the intestinal tract. Report suggest that anti-inflammatory drug plays a crucial role in the protection of UC. The recent study demonstrated that columbianadin has a protective effect against UC induced by dextran sulfate sodium (DSS) in rats through the modulation of HO-1/Nrf2 and TLR4-NF-κB signaling pathways.

Material and methods: In this study, Swiss Wistar rats were utilized, and UC was induced using 2% DSS. The treatment regimen included oral administration of columbianadin (5, 10 and 15 mg/kg) and sulfasalazine to the rats. The body weight, spleen index, disease activity index (DAI), colon length, food and water intake were estimated. Moreover, antioxidant, cytokines, inflammatory and apoptosis parameters were determined. mRNA expression levels were also quantitatively analyzed.

Results: Columbianadin treatment significantly (P < 0.001) boosted the body weight and suppressed the DAI. Columbianadin significantly (P < 0.001) enhanced the colon length and repressed the spleen index along with enhanced food and water intake. Columbianadin significantly (P < 0.001) suppressed the level of lactate dehydrogenase (LDH), myeloperoxidase (MPO) and altered the level of oxidative stress parameters such as catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), malonaldehyde (MDA), nitric oxide (NO), SA; cytokines level such as interleukin (IL)-1, 1β, 6, 10, 17, 18, TNF-α; inflammatory parameters viz., cyclooxygenase-2 (COX-2), prostaglandin (PGE₂), inducible nitric oxide synthetase (iNOS), nuclear factor kappa B (NF-κB), transforming growth factor (TGF-β); apoptosis parameters include Bax, Bcl-2, Bcl-2/Bax ratio, caspase-1 and A-caspase-3 activity, respectively. Columbianadin significantly altered the mRNA expression of IFN-γ, IL-6, IL-1β, IL-8, TNF-α, NF-κB, TLR4, Bcl-2, caspase-9, Bax, p38, ASC, MCP-1, ZO-1, and Ocln. While this study focused on COX-2 modulation as a marker of inflammatory response, no direct measurements or inferences were made regarding leukotriene activity, which involves a separate lipoxygenase pathway.

Conclusion: Columbianadin exhibited the protective effect against DSS-induced UC via alteration of HO-1/Nrf2 and TLR4-NF-κB signaling pathway.