Oyster polysaccharides relieve DSS-induced colitis via anti-inflammatory and maintaining the physiological hypoxia.

Oyster polysaccharides (OPS) possess potent anti-inflammatory properties and mediate gut microbiome. The research aimed to investigate the beneficial effect of OPS on attenuating colitis. OPS administration decreased the disease activity index and suppressed the increase in colon length. Hematoxylin and eosin staining results displayed that OPS restored the DSS-induced histopathological damage. After oral administration of OPS, myeloperoxidase activity and pro-inflammatory cytokines (TNF-α) in colitis mice were inhibited, while IL-10 was elevated. Western blotting results revealed that OPS improved the expression of tight junction proteins (ZO-1, Claudin-4, and Occludin). Additionally, OPS stabilized the expression of hypoxia-inducible factor-1α (HIF-1α) and prevented the levels of bacterial endotoxin (lipopolysaccharides). OPS activated barrier-protective genes (intestinal trefoil factor) via mediating HIF-1α. These results indicated that OPS alleviated DSS-induced colitis by inhibiting inflammation and regulating HIF-1α. OPS would be a potential candidate to alleviate DSS-induced colitis.