Asperosaponin VI alleviates TNBS-induced Crohn’s disease-like colitis in mice by reducing intestinal epithelial cell apoptosis via inhibiting the PI3K/AKT/NF-κB signaling pathway
Objectives: This study aimed to evaluate the effects of asperosaponin VI (AVI) on intestinal epithelial cell apoptosis and intestinal barrier integrity in a murine model of Crohn’s disease (CD)-like colitis, and to elucidate the underlying molecular mechanisms.
Methods: Male C57BL/6 mice with TNBS-induced CD-like colitis were orally administered either saline or AVI (150 mg/kg/day) for 6 consecutive days. Disease progression was assessed through body weight monitoring, colon length measurements, Disease Activity Index (DAI) scores, and histopathological analysis. Inflammatory cytokine levels and tight junction protein expression were quantified using ELISA and RT-qPCR. The impact of AVI on epithelial barrier function and apoptosis was further investigated in both mouse intestinal tissues and TNF-α-stimulated Caco-2 cells using immunofluorescence staining, TUNEL assays, and Western blotting. Mechanistic insights were explored via network pharmacology, and validated using TUNEL assays, Western blot analysis, and pharmacological intervention.
Results: AVI treatment markedly attenuated weight loss, colon shortening, increased DAI scores, and histological inflammation in TNBS-induced colitis. It also preserved intestinal villi architecture and goblet cell integrity while significantly reducing pro-inflammatory cytokine expression. AVI effectively prevented tight junction protein loss and epithelial cell apoptosis in both in vivo and in vitro models. KEGG pathway analysis implicated the PI3K/AKT/NF-κB signaling cascade as a key target of AVI. This was supported by decreased levels of phosphorylated PI3K, AKT, and p65 in AVI-treated mice and Caco-2 cells. Moreover, Recilisib, a PI3K/AKT pathway activator, reversed AVI’s inhibitory effects on this pathway and TNF-α-induced apoptosis. AKT1 knockdown experiments confirmed that suppression of the PI3K/AKT pathway mediates the downstream inhibition of NF-κB activation.
Conclusions: AVI ameliorates TNBS-induced CD-like colitis by protecting intestinal epithelial cells from apoptosis and preserving barrier function, primarily through inhibition of the PI3K/AKT/NF-κB signaling pathway.