[Moslosooflavone ameliorates dextran sulfate sodium-induced colitis in mice by suppressing intestinal epithelium apoptosis via inhibiting the PI3K/AKT signaling pathway].

Objectives: To investigate the effect of moslosooflavone (MOS) for ameliorating dextran sulfate sodium (DSS)-induced colitis in mice and the underlying molecular mechanism.

Methods: C57BL/6J mice with or without DSS exposure in the drinking water were both randomized into two groups for treatment with intraperitoneal injections with MOS (200 mg/kg) or normal saline for 7 days (n=6). Disease severity of the mice was assessed by observing changes in body weight, colon length, histopathology (HE staining), intestinal barrier function, and TUNEL staining. In the in vitro studies, lipopolysaccharide (LPS)-stimulated mouse colon organoids were treated with MOS (120 μmol/L) for 24 h, and the changes in barrier dysfunction and inflammation were analyzed. Network pharmacology and Western blotting were employed to identify functional pathways and apoptotic protein regulation associated with the therapeutic effect of MOS on colitis.

Results: In the mouse models of DSS-indcued colitis, MOS treatment significantly reduced body weight loss, disease activity index (DAI) scores and colon shortening, ameliorated colonic histopathological changes and inflammation, and lowered pro-inflammatory cytokine levels (TNF-α, IL-1β, IL-6, and IFN-γ). MOS effectively restored intestinal barrier integrity in the mice by reducing serum FITC-dextran and I-FABP concentrations while enhancing the tight junction proteins (ZO-1 and claudin-1). In the colon organoids, MOS significantly suppressed LPS-induced inflammatory responses and epithelial barrier disruption. Western blotting revealed that MOS downregulated C-caspase-3 and BAX and upregulated Bcl-2 expressions in both models. Mechanistically, MOS suppressed PI3K and AKT phosphorylation in both DSS-treated mouse colonic tissues and LPS-stimulated organoids.

Conclusions: MOS alleviates experimental colitis in mice by inhibiting intestinal epithelial apoptosis via inhibiting the PI3K/AKT pathway, thereby restoring intestinal barrier integrity and reducing inflammation.