Antidiabetic and antioxidant activities of eight medicinal mushroom species from China

The objective of the current study was to verify antidiabetic effects of different types of mushrooms as folk medicines in treating diabetes. The antidiabetic effects were evaluated by in vitro α-glycosidase and aldose reductase (AR) inhibitory assays and antioxidant activity assay. Ganoderma lucidum extract exhibited the best dose-dependent inhibitory activity against α-glycosidase with IC50 at 4.88 mg/mL, and also exhibited aldose reductase inhibitory potential with IC50 value of 9.87 mg/mL. Tremella fuciformis demonstrated the highest AR inhibitory activity (IC50=8.39 mg/mL). Antioxidant activities of selected mushrooms were evaluated based on the total phenolic content (TPC), total flavonoids content (TFC), and DPPH free radical scavenging activity. The result showed that G. lucidum contained the highest TPC (39.3 mg GAE/g sample extract), TFC (15.1 mg CE/g sample extract), and the strongest DPPH free radical scavenging activity (IC50=3.66 mg/mL) among the mushroom samples.