Identification of bioactive polysaccharide from Pseudostellaria heterophylla with its anti-inflammatory effects

[Display omitted] •TLR4 was activated on the membrane of mononuclear macrophage after PHP treatment.•After PHP treatment, the intestinal mucosa was more complete.•The contents of ScFA increased after PHP treatment.•The type and abundance of intestinal flora in colitis mice were changed after PHP treatment. Radix Pseudostellariae, the root of Pseudostellaria heterophylla (Miq.) Pax, has historically been used as medicine food homology plant for thousand years in China. Herein, PHP, a water soluble polysaccharides from Radix Pseudostellariae, was isolated and identified by HPGPC, GC–MS, FT-IR, and scanning electron microscopy. Results showed that PHP (Mw = 1.07 × 104 kDa) mainly consisted of rhamnose, galacturonic acid, glucose, galactose, arabinose, fucose in a molar ratio of 0.055:0.208:0.306:0.055:0.753:0.594:0.014. It contained nine types of linkages, including → 6)-Galp(A)-(1→, →6)-Galp-(1→, →3)-Arap-(1→, Galp-(1→, →3)-Rhap-(1→, Glup-(1→, →3)-Araf-(1→, →2,3,4)-Manp-(1 → and → 3,4)-Fucp-(1→. Morphology analysis showed that PHP took flakes with irregular size and properties. It significantly activated TLR4 in vivo. In DSS induced mouse-acute-colitis molds, PHP90-3a improved and the colon length was on ulcerative in mice. the production of IL-1β and TNF-α were decreased. The intestinal mucosa was more complete, there were much more goblet cells, and the infiltration of lymphocytes and neutrophils was significantly decreased. The content of SCFA increased, whereas acetic acid, propionic acid and butyric acid increased. 16S RNA sequencing and OTUs cluster analysis revealed that Bacteroides and Pseudomonas were the dominant intestinal flora. The analysis of community thermogram showed that the abundance ratio of Pseudomonas and Bacteroides (F/B) was significantly lower than the dominant group and significantly inhibited the levels of Verrucomicrobia and Akkermansia. Altogether, the data suggested that the anti-inflammatory activity might be implicated with the activation of TLR4 signal pathways, reducing IL-1β and TNF-α, and the regulation of mucosal immunity and the composition of intestinal flora.