Spiraea prunifolia var. simpliciflora ethanol extract alleviates DSS-induced colitis by modulating MAPK signalling and preserving intestinal barrier integrity

This study investigated the anti-inflammatory and barrier-protective effects of Spiraea prunifolia var. simpliciflora ethanol extract (SPSE) in lipopolysaccharide-stimulated macrophages and dextran sulfate sodium (DSS)-induced colitis in mice. SPSE suppressed nitric oxide production and down-regulated pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) by inhibiting phosphorylation of ERK, JNK, and p38 MAPK. In vivo, SPSE alleviated weight loss, colon shortening, and histological damage, accompanied by reduced cytokine expression and MAPK activation in colonic tissue. Moreover, SPSE restored epithelial tight junction proteins, including ZO-1, occludin, and claudin-1, thereby preserving intestinal barrier integrity. Molecular docking suggested that caffeoyl-type constituents of SPSE interact with transforming growth factor β-activated kinase 1 (TAK1), an upstream regulator of MAPK signalling. These findings demonstrate that SPSE mitigates experimental colitis by modulating MAPK signalling and maintaining epithelial integrity, supporting its potential as a functional food ingredient for intestinal health. • ⸱ SPSE suppressed proinflammatory cytokine production in macrophages. • ⸱ SPSE ameliorated DSS-induced colitis and restored colon barrier integrity. • ⸱ SPSE inhibited MAPK signalling and preserved tight junction proteins. • ⸱ SPSE, rich in caffeoyl derivatives, shows potential as a functional food ingredient for IBD management.