Type-2 diabetes affects an increasing percentage of the world's population and its control through dietary management, involving the consumption of health-promoting foods or their derived supplements, is a common strategy. Several mushroom species have been demonstrated to be endowed with antidiabetic properties, resulting from their ability in improving insulin sensitivity and production, or inhibiting the carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase. This study aimed to investigate for the first time the hypoglycemic properties of the edible mushroom Leccinum scabrum (Bull.) Gray. Mushroom extracts were prepared through the microwave-assisted extraction (MAE) technique using green solvents with different polarity degrees. The inhibition activity of all the obtained extracts on both α-glucosidase and α-amylase was evaluated and the highest activity was observed for the EtOAc extract which showed an IC50 value about 60-fold lower than the reference compound 1-deoxynojirimycin (DNJ) on α-glucosidase (0.42 ± 0.02 and 25.4 ± 0.6 µg/mL, respectively). As expected on the basis of the literature data concerning both α-glucosidase and α-amylase inhibition, a milder inhibition activity on pancreatic α-amylase was observed. Preliminary in vivo tests on Drosophila melanogaster carried out on the most active obtained extract (EtOAc) confirmed the in vitro observed hypoglycemic activity. Finally, the EtOAc extract metabolic profile was determined through GC-MS and HRMS analyses.
Keywords: Boletaceae; GC-MS; HRMS; Leccinum scabrum; fatty acids; medicinal mushrooms; mycochemicals; type-2 diabetes; α-amylase; α-glucosidase.