Cyclocarya paliurus polysaccharide alleviates liver inflammation in mice via beneficial regulation of gut microbiota and TLR4/MAPK signaling pathways

The study was to investigate the anti-inflammatory effect of Cyclocarya paliurus polysaccharides (CP) on carbon tetrachloride (CCl4) induced mice and explore its underlying mechanism. Based on a mouse model of CCl4 induced liver inflammation and pretreatment with CP. Results showed that CP significantly decreased the levels of the proinflammatory cytokines (NO, TNF-α, IL-1β) as well as the proteins expression levels of COX-2 and iNOS in the liver. TLR4 and MAPK pathways were down-regulated after CP administration. Furthermore, 16S rDNA showed that CP increased the Firmicutes/Bacteroidetes ratio and the abundance of probiotics (Unclassified Clostridiales) as well as decreased abundances of pathogenic bacteria (Proteobacteria, Helicobacter and Aerococcus) compared to model group. Moreover, CP treatment increased the SCFAs levels in CCl4 induced mice. These findings suggested that CP act as prebiotics in ameliorating the liver inflammation in mice caused by CCl4 through regulating the gut microbiota composition and increasing the concentration of SCFAs.