Lumefantrine ameliorates DSS-induced colitis by targeting FLI-1 to suppress NF-κB signaling.

BACKGROUND: Current therapeutic options for inflammatory bowel disease (IBD) remain suboptimal due to limited efficacy, significant side effects, and high relapse rates, necessitating novel treatment strategies. Lumefantrine, a clinically established antimalarial drug, emerges as a compelling repurposing candidate based on its putative anti-inflammatory activity, though its efficacy and mechanism in IBD remain unexplored. METHODS: A murine IBD model was induced by 3% dextran sulfate sodium (DSS). Mice received oral Lumefantrine (20 mg/kg/day) for 7 days. Disease progression was monitored via disease activity index (DAI) scoring and histological analysis. Serum cytokines (IL-1β, IL-6, TNF-α) and colonic inflammatory mediators (Cox-2, iNos) were quantified by ELISA and qPCR. Tight junction proteins (Claudin-1, ZO-1) were assessed by immunohistochemistry and Western blot. Molecular targets were identified through computational docking and pull-down assays. Additionally, NF-κB signaling modulation was assessed in lipopolysaccharide (LPS)-stimulated intestinal epithelial cells (IEC-6 and NCM460) via Western blot analysis. RESULTS: Oral administration of Lumefantrine significantly attenuated disease activity index (DAI) scores and restored intestinal barrier integrity through upregulation of epithelial tight junction proteins Claudin-1 and ZO-1. Treated mice exhibited reduced serum levels of IL-1β, IL-6 and TNF-α, along with decreased colonic expression of inflammatory mediators cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNos). Computational and experimental approaches identified FLI-1 a transcription factor upregulated in IBD colon tissues as Lumefantrine's direct binding target. This interaction mediated suppression of NF-κB signaling, specifically downregulating phosphorylation of IκBα and p65 in LPS-stimulated intestinal epithelial cells. CONCLUSION: Lumefantrine ameliorates experimental colitis through FLI-1-dependent inhibition of the NF-κB pathway, demonstrating high repurposing potential as an IBD therapeutic.