A sodium carbonate-soluble polysaccharide from Amomum tsao-ko attenuates colitis via ZO-1-mediated barrier restoration and transcriptomics-implicated mucin glycosylation.

In this study, four polysaccharides (water-soluble, ATPW; 0.05 M Na2CO3-soluble ATP-SC; 0.1 M NaOH soluble ATP-SA1; and 0.5 M NaOH soluble ATP-SA2) were sequentially extracted from Amomum tsao-ko. Their physiochemical properties, monosaccharide compositions, molecular weights, and structural features were characterized. Their bioactivities were compared in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice, focusing on repairing the mucus barrier. Among them, ATP-SC displayed the strongest protective effects. Transcriptomics indicated that ATP-SC modulated mucin-type O-glycan biosynthesis, tight junction, and inflammatory signaling pathways associated with its mechanism of action. Furthermore, in vivo validation revealed that ATP-SC enhanced intestinal barrier integrity, while decreasing immune cells infiltration. In vitro, ATP-SC suppressed inflammation in macrophages, and restored tight junction integrity in damaged intestinal epithelial cells. Collectively, this study identifies ATP-SC as the key bioactive polysaccharide from A. tsao-ko, acting through mucin glycosylation-driven mucus barrier restoration, highlighting its potential as a functional food-derived protective agents for UC.