Hesperetin alleviates DSS induced colitis by inhibiting TLR2/NF-κB and restoring intestinal barrier.

OBJECTIVE: The pathogenesis of ulcerative colitis (UC) is closely associated with excessive intestinal inflammation and epithelial barrier disruption. Hesperetin possesses natural anti-inflammatory properties, but its protective mechanisms remain unclear. METHODS: A DSS-induced murine UC model was established. Mice were divided into normal control, DSS model, mesalazine positive control, and low- and high-dose hesperetin groups. Colon length was measured, and histopathological evaluation was performed via hematoxylin and eosin (HE) staining. Body weight, disease activity index (DAI), TLR2/NF-κB pathway, inflammatory cytokines, tight junction proteins, ER stress and autophagy markers, and MHC II antigen presentation genes (H2-aa and H2-ab) were assessed. Additionally, AB-PAS staining was used to evaluate goblet cell abundance, and serum D-lactate (D-LA) level was detected to reflect intestinal permeability and barrier function. RESULTS: Hesperetin attenuated body weight loss, DAI scores and colon shortening, and dose-dependently inhibited TLR2/NF-κB overactivation, downregulated pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and iNOS, while upregulating the anti-inflammatory cytokine IL-10. Hesperetin effectively restored the expression of tight junction proteins ZO-1 and occludin, reduced the elevated serum D-LA level induced by DSS, and alleviated DSS-triggered goblet cell loss confirmed by AB-PAS staining. Moreover, hesperetin suppressed aberrant expression of ATF6 and SQSTM1, and reversed the upregulation of MHC II antigen presentation genes (H2-aa and H2-ab1). The high-dose hesperetin exhibited therapeutic efficacy comparable to mesalazine. CONCLUSION: Hesperetin alleviates DSS-induced colitis through multiple pathways, representing a promising natural candidate for UC prevention and treatment.