Structural characterization of water-soluble polysaccharide from Arctium lappa and its effects on colitis mice

Abstract In this study, water-soluble polysaccharide from Arctium lappa was extracted, isolated and purified to be a fraction (ALP-1). Characterization of structure revealed that ALP-1 was a kind of fructan with a molecular weight of 5.12 × 10 3  Da. ALP-1 was composed of (2→ 1)-β- d -fructofuranose backbone linked to a terminal of (2 → 1)-α- d -glucopyranose at the non-reducing end and a (2 → 6)-β- d -fructofuranose branching. DSS-induced colitis mice were used to determine the inhibitory effects of ALP-1 on gut inflammation. Results indicated that ALP-1 could significantly ameliorate the dysregulation of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and anti-inflammatory cytokine (IL-10) caused by colitis. Besides, as compared with model group, the abundance of Firmicutes , Ruminococcaceae , Lachnospiraceae and Lactobacillus were significantly increased with ALP-1 treatment. And ALP-1 could significantly inhibit the levels of Proteobacteria , Alcaligenaceae , Staphylococcusand and Bacteroidetes . Therefore, ALP-1 may be effective in protecting mice from DSS-induced colitis.