Structural elucidation of polysaccharide from fresh Areca catechu L. and its mitigation effect on DSS-induced colitis in mice.

Ulcerative colitis (UC) is an inflammatory bowel disease and has emerged as a public health challenge worldwide. The present study aimed to isolate polysaccharide from fresh Areca catechu L. (FAP1a) and to investigate its potential mechanism for ameliorating UC symptoms in a mouse model of UC. The results indicated that the molecular weight of FAP1a was approximately 65 kDa and consisted of arabinose, mannose and galactose, with the main chain probably consisting of →3,6)-β-Gal-(1 → and →2,4,6)-β-Man-(1→. FAP1a effectively attenuated weight loss and colonic tissue damage in mice. FAP1a modulated gut microbial composition by increasing the abundance of beneficial bacteria such as Ligilactobacillus, Dubosiella, Ruminococcus and Lactobacillus. Meanwhile, FAP1a upregulated the expression of beneficial metabolites including L-glutamate, D-mannose, and D-tagatose mainly through the alanine, aspartate and glutamate metabolism and galactose metabolism pathways. The above results elucidated that FAP1a could alleviate UC symptoms through modulation of the gut microbial structure and serum metabolites. These findings highlight the potential of FAP1a as a novel therapeutic agent for UC and provided insights into the potential mechanisms underlying its therapeutic effects.