Polysaccharides from Acanthopanax senticosus enhances intestinal integrity through inhibiting TLR4/NF-B signaling pathways in lipopolysaccharide-challenged mice

To investigate the role of polysaccharide from Acanthopanax senticosus (ASPS) on lipopolysaccharide (LPS)-induced intestinal injury, mice in three treatments were administrated orally with or without ASPS (300 mg/kg body weight) for 14 days, followed by challenge with LPS or saline. At 4 h post-injection, blood and intestinal samples of six mice / treatment were collected. The results showed ASPS ameliorated LPS-induced intestinal morphological deterioration, proven by improved villus height (P < 0.05) and villus height:crypt depth ratio (P < 0.05). ASPS also elevated the mucosal barrier of LPS-challenged mice, supported by reduced plasma diamine oxidase (DAO) activity (P < 0.05) and L-lactate (P < 0.05), increased mucosal DAO activity (P < 0.05) as well as enhanced intestinal tight junction proteins expression involving occludin-1 (P < 0.05) and zonula occludens-1 (P < 0.05). In addition, ASPS decreased LPS-induced secretion of inflammatory mediators, including tumor necrosis factor (TNF)- (P < 0.05) and prostaglandin E-2 (P < 0.05). Also, ASPS down-regulated messenger RNA expression of toll-like receptor 4 (TLR4) and its downstream signals, including myeloid differentiation factor 88 (P < 0.05), TNF- receptor-associated factor 6 (P < 0.05), as well as nuclear factor (NF)-B p65 (P < 0.05) and its protein expression. These findings suggest that ASPS improves intestinal integrity under inflammation conditions connected with inhibiting TLR4/NF-B signaling pathways.