Antioxidant and antidiabetic activities of mycelial and fruit-body extracts from Mycoleptodonoides aitchisonii

Mycoleptodonoides aitchisonii (Berk.) Maas Geest. is a culinary mushroom that is recognized as both a nutritious food and an excellent source of bioactive compounds. The purpose of this study was to investigate the antioxidant and antidiabetic properties of M. aitchisonii (MA) both in vitro and in vivo. Total oxyradical scavenging capacity (TOSC) assays revealed that fruit-body extracts had higher antioxidant capacity than mycelial extracts, 0.9-fold higher as measured by peroxynitrite (PN) scavenging assay, 3.7-fold higher as measured by peroxyl radical (PR) scavenging assay, and 1.6-fold as measured by hydroxyl radical (HR) scavenging assay, respectively. The assay of Akt phosphorylation, which is inhibited by Interleukin 6 (IL-6) in the signal transduction pathway for diabetes, was employed to evaluate the antidiabetic activity. Fruit-body extracts significantly increased Akt phosphorylation according to the fruit-body extract concentration, with a maximum increment of 77% at a concentration of 100 μg/mL compared to 51.4% decrement caused by IL-6, but there was no effect of mycelial extracts. Treatment with 5% MA fruit-body powder and streptozotocin (STZ) decreased the blood sugar level to 233.8 mg/dL in diabetic mice compared to 333.8 mg/dL after treatment with STZ alone. Additionally, MA treatment lowered total cholesterol (TC), triglyceride (TG), and LDL-cholesterol levels, while it increased the HDL-cholesterol level. All these findings indicate that fruit-body of M. aitchisonii has potential utility in preventing various diseases such as disorders of sugar and lipid metabolism.