Structural characterization of galactoglucomannan from medicinal fungus Hypocrella bambusae and its protective effects on drosophila intestinal injury

• HB-0.1, a heteropolysaccharide from Hypocrella bambusae , features a (1→6)-α-D-mannopyranose backbone with β-D-galactofuranose and α-D-glucopyranose side chains, providing new insights into fungal polysaccharides. • HB-0.1 protects against oxidative stress-induced intestinal injury in a Drosophila model, reducing ROS levels and mitigating stem cell overproliferation. • The polysaccharide modulates the JNK-MAPK pathway, showing its potential as a therapeutic agent for intestinal damage and oxidative stress. Despite traditional medicinal use, the polysaccharides of Hypocrella bambusae remain underexplored. This study aimed to characterize a novel polysaccharide HB-0.1 extracted and purified from the medicinal fungus Hypocrella bambusae and evaluate its therapeutic potential in mitigating intestinal injury. The galactoglucomannan HB-0.1, was structurally characterized as a heteropolysaccharide with a (1→6)-α-D-mannopyranose backbone and branching side chains containing β-D-galactofuranose and α-D-glucopyranose residues. Functional evaluations in a Drosophila model demonstrated that HB-0.1 significantly mitigated SDS-induced intestinal injury, dose-dependently reducing reactive oxygen species (ROS), inhibiting intestinal stem cell (ISC) over proliferation, and prolonging lifespan. Mechanistic studies revealed that HB-0.1 regulated the JNK-MAPK signaling pathway, balancing oxidative stress and epithelial regeneration. These findings highlight the unique structural and therapeutic potential of HB-0.1 for intestinal protection and provide a basis for future development of bamboo-derived fungal polysaccharides.