Hypoglycemic Effect of the Degraded Polysaccharides from the Wood Ear Medicinal Mushroom Auricularia auricula-judae (Agaricomycetes)

Auricularia auricula-judae is an important culinary-medicinal mushroom. The A. auricula-judae polysaccharides (AAPs) were prepared from A. auricula-judae in the early stage through alkali extraction and deproteination with the Sevag method, and optimal acid hydrolysis conditions were established by Box-Behnken to prepare the degraded polysaccharides (AAPs-F) from AAPs. In this study, a nonenzymatic glycosylation reaction system was used for the evaluation of the inhibitory effects on the formation of advanced glycation end products (AGEs). In addition, high glucose resistance was assessed by glucose consumption of HepG2 cells and the lifespan of Caenorhabditis elegans under high sugar stress. It was found that both 0.5 mg.mL(-1) AAPs and 0.2 mg.mL(-1) AAPs-F could significantly inhibit AGE formation in short- and long-term glycosylation (P < .05) in a dose-dependent manner, determined by ultraviolet and fluorospectrophotometry. It indicated activity against AGE formation for different concentrations of AAPs and AAPs-F. AAPs-F at 0.5 mg.mL(-1) significantly enhanced the glucose absorption of HepG2 cells by 24.4% (P < .05) in a dose-dependent manner at 24 h, and markedly extended the lifespan of C. elegans by 32.9% (P < 0.05) under high sugar stress conditions. This study demonstrated that the derived hydrolysates produced by the hydrolysis of acid had a prominent effect on the inhibition of AGE formation and relieved the stress state caused by high sugar levels.