Abstract
The leaves and bark of Litsea species have traditionally been used as folk medicine to treat pain, headache, inflammation, diarrhea, and gastroenteritis. This study investigated whether dietary supplementation with Litsea cubeba leaves could preserve key functional components of the colonic barrier in a mouse model of dextran sulfate sodium (DSS)-induced ulcerative colitis. Male C57BL/6J mice were fed a control diet or a diet supplemented with L. cubeba leaves (20 g/kg diet) for 2 weeks, and colitis was induced by administering 3% (w/v) DSS in drinking water during the final week. Dietary L. cubeba leaf supplementation significantly attenuated DSS-induced body weight loss and suppressed the increase in Disease Activity Index. In addition, L. cubeba leaf supplementation attenuated DSS-induced reduction in fecal immunoglobulin A content and significantly prevented the reduction in fecal mucin content, which are key functional components of the colonic barrier. Furthermore, plasma levels of the inflammatory chemokine monocyte chemoattractant protein-1 were significantly decreased by L. cubeba leaf supplementation, accompanied by a reduction in plasma alanine aminotransferase activity, a marker of liver injury. These findings suggest that dietary L. cubeba leaf supplementation alleviates DSS-induced ulcerative colitis in mice, at least in part, by preserving key functional components of the colonic barrier rather than predominantly through direct suppression of colonic inflammatory gene expression.