Strategic ultrasonic degradation enhances immunomodulatory and hypolipidemic activities of Hericium Erinaceus β-glucan.

Bioactive β-glucans from Hericium erinaceus possess health benefits, yet the structure-function relationships of these polysaccharides remain incompletely elucidated. This study employed an ultrasonic degradation strategy to modify a high-molecular-weight β-glucan (H6PC20, 2.39 × 106 g/mol) from its fruiting bodies. Ultrasonic treatment yielded three degraded fractions (H6PC20 A-C) with molecular weights ranging from 4.60 × 105 g/mol to 1.84 × 105 g/mol, accompanied by a sharp reduction in intrinsic viscosity from 1231.99 mL/g to 108.76 mL/g. Structural analyses revealed that ultrasound treatment preserved the primary structure, main functional groups, and branching patterns of degraded fractions, while causing significant alterations in spatial conformation and microscopic morphology. Notably, compared to native H6PC20, the optimized fraction H6PC20B exhibited dramatically enhanced bioactivity, reflecting in increasing nitric oxide production by 41.6% in RAW 264.7 macrophages and reducing lipid accumulation by 99.2% in the zebrafish model. These enhancements are attributed to the reductions in molecular weight and viscosity, coupled with alterations in apparent morphology and spatial conformation. This study demonstrates that ultrasonic degradation is an effective strategy for preparing bioactive β-glucans, thereby facilitating the potential application of H. erinaceus polysaccharides.