Structural characterization of Dendrobium huoshanense polysaccharides and its gastroprotective effect on acetic acid-induced gastric ulcer in mice.

Dendrobium huoshanense (DH) is a medicinal plant known for its efficacy in improving gastrointestinal diseases. In this study, a novel polysaccharide, DHPs-1, was isolated and purified from DH, and its structural characteristics were analyzed using advanced methodologies, including monosaccharide composition analysis, methylation, FT-IR spectroscopy, and NMR. The gastroprotective effect of DHPs-1 was assessed using a mouse model of chronic gastric ulcers induced by acetic acid. The results revealed that DHPs-1 is primarily composed of mannose (Man) and glucose (Glc) with a molecular weight of 3.137 × 106 Da. The purified polysaccharide DHPs-1 is primarily composed of →4)-β-D-Glcp-(1 → and →4)-β-D-Manp-(1→, with an acetyl substitution at the C-2 position of Man. DHPs-1 exhibited a pronounced protective effect against acetic acid-induced chronic gastric ulcers in mice by modulating gastric defense factors and inflammatory mediators. Furthermore, DHPs-1 downregulated the expression of p-p65/p-IκBα in gastric tissues, thereby mitigating gastric mucosal injury. These findings suggest that DHPs-1 has the potential to serve as an effective gastric mucosal protective agent and could be developed into functional foods and dietary supplements.