Armillaria mellea: phenolic content, in vitro antioxidant and antihyperglycemic effects.

Armillaria mellea, known as honey mushroom, has been used both as food and medicine. Aim: In this work, the ethanolic and hydromethanolic extracts from Armillaria mellea fruiting bodies were investigated for their phenolic content, antioxidant and antihyperglycemic effects (in vitro studies). Material and methods: The total phenolics were quantified using Folin-Ciocalteu assay. The antioxidant activity was evaluated by testing the free radical scavenging capacity, reducing power and ferrous ion chelating ability; in addition, the capacity to inhibit 15-lipoxygenase was also assessed. The antihyperglycemic activity was investigated by α-glucosidase assay. Results: Total phenolic contents of 21.68 ± 0.06 and 5.70 ± 0.28 mg/g were determined in the hydromethanolic and ethanolic extracts, respectively. The hydromethanolic extract showed higher free radical scavenging and reducing abilities (EC50 = 452.6 ± 2.7, 140.57 ± 1.45 and 129.45 ± 0.98 μg/mL in DPPH, ABTS and reducing power assays, respectively). The ethanolic extract proved to be more efficient in the ferrous ion chelation, 15-lipoxygenase and a-glucosidase inhibition assays (EC50 = 67.93 ± 0.35, 290.93 ± 2.05 and 8.54 ± 0.06 μg/mL, respectively). Conclusions: Armillaria mellea extracts showed antioxidant and antihyperglycemic potential in in vitro models and therefore they are promising candidates for the development of dietary supplements and pharmaceutical products.