Euonymus alatus extract ameliorates DSS-induced experimental colitis and attenuates NLRP3 inflammasome-associated pyroptosis in macrophages

Euonymus alatus (Thunb.) Siebold has been traditionally used in East Asian medicine for dysentery and inflammatory disorders. However, its effects on intestinal inflammation and barrier injury remain unclear. To evaluate E. alatus extract (EEA) in dextran sulfate sodium (DSS)-induced colitis and examine inflammatory, inflammasome-related, pyroptosis-associated, and epithelial barrier responses. EEA was profiled using ultra-high-performance liquid chromatography–tandem mass spectrometry. Colitis was induced in male C57BL/6 mice (five groups, n = 8/group) using two cycles of 2.0% DSS in drinking water (6 and 5 days of DSS exposure separated by a 7-day DSS-free interval). Cytokine-stimulated Caco-2 epithelial cells and lipopolysaccharide/adenosine triphosphate-stimulated J774A.1 macrophages were also used. Histological and molecular assessments, barrier assays, RNA sequencing, and network pharmacology analyses were performed. EEA contained flavonoids and phenolic and reduced weight loss, disease activity, and histological injury; high-dose EEA increased colon length from 6.67 ± 0.18 to 7.58 ± 0.13 cm (p = 0.003 vs. N.C.). EEA decreased MPO- and F4/80-positive infiltration and inflammatory/inflammasome-related transcripts. In Caco-2 cells, EEA improved barrier function and increased ZO-1 and occludin expression. In J774A.1 macrophages, EEA reduced pyroptotic cell death, IL-1β and IL-18 release, ASC oligomerization and specks, cleaved caspase-1, mature IL-1β, and GSDMD-NT. Selected phytochemicals partly reproduced these effects. Transcriptomic and network analyses implicated inflammatory and barrier-related pathways. EEA attenuated DSS-induced experimental colitis and modulated inflammatory, inflammasome-related, epithelial barrier, and pyroptosis-associated responses. Further validation in other experimental models is needed to establish its broader relevance to IBD.