Inhibitory effects of Lentinus edodes mycelia polysaccharide on α-glucosidase, glycation activity and high glucose-induced cell damage

Abstract

At present, diabetes and diabetic complications have become one of the serious diseases affecting human health. In this study, the inhibitory effects of Lentinus edodes mycelia polysaccharide (LMP) on α-glucosidase activity, the formation of advanced glycation end products (AGEs) and high glucose-induced human umbilical vein endothelial cells (HUVECs) damage were explored. The interaction between LMP and α-glucosidase and the inhibition against AGEs formation were investigated with spectroscopic techniques. The results revealed that LMP had a reversible inhibition on α-glucosidase activity in a mixed-type manner. When the concentration of LMP was 2.7 mM, the inhibition rate was 34.38 %. LMP quenched the fluorescence of α-glucosidase through the static quenching and formed the LMP-α-glucosidase complex. At 310 K, the number of binding sites (n) and binding constant (K_b) were 1.01 and 3.71 × 10⁴ L mol^-1, respectively. In addition, LMP could inhibit the formation of AGEs. Compared with 40 mM glucose treatment group, treatment with 0.05 mM LMP for 48 h increased the cell viability from 70.17% to 91.14% and decreased ROS production from 3.33-fold to 1.21-fold. LMP inhibited high glucose-induced activation of MAPK signaling pathways. These findings may promote the application of LMP in the functional food industry.

Keywords: Advanced glycation end products; Apoptosis; DCFH-DA (PubChem CID: 104913); Dimethyl sulfoxide (PubChem CID: 679); Glucose (PubChem CID: 5793); Hoechst 33258 (PubChem CID: 135705211); Lentinus edodes mycelia polysaccharide; Oxidative stress; Penicillin (PubChem CID: 5904); Sodium carbonate (PubChem CID: 10340); Streptomycin (PubChem CID: 19649); Thiazolyl blue tetrazolium bromide (PubChem CID: 64965); p-nitrophenol (PubChem CID: 980); p-nitrophenyl-α-D-glucopyranoside (PubChem CID: 259380); α-glucosidase.