Evaluation of antioxidant properties of wood decay fungi

Abstract

Fungi have been reported as useful sources of possible biocompounds which are applied in many fields of human life such as food products, therapeutic, pharmaceutical purposes and healthy cosmetics. The objective of this study was to evaluate the antioxidant properties of five species of wood decay fungi Pycnoporus sanguineus, Flavodon flavus, Fomitopsis ostreiformis, Physisporinus vitreus and Ganoderma enigmaticum. Five species were cultured in sawdust in 30 days and the mycelium was collected for ethyl acetate extraction. Folin-Ciocalteau method and aluminum chloride colorimetric assay were used to determine total phenolic and flavonoid contents of mycelial extracts. For evaluation of potential antioxidant activity, scavenging capacity on DPPH radicals, hydrogen peroxide and reducing power were investigated. F. ostreiformis showed the highest extraction weight with 190.93 mg dry extract weight/g of mycelium weight. The phenolic contents were in the range of 17.27 – 48.21 mg GAE/g DW, flavonoid contents were in the range of 24.74 – 102.02 mg QE/g DW with the highest values belong to P. sanguineus and F. flavus, respectively. Especially, F. flavus certified the strongest antioxidant ability among five species with lowest IC50 value of 290.42 μg/mL and 996.79 μg/mL for in DPPH free radical and hydrogen peroxide scavenging activity, respectively. P. vitreus and G. enigmaticum expressed the lowest abilities in antioxidant capacity out of five species however their abilities were good in comparison with common medicine mushroom. The results demonstrated that the biocompounds from ethyl acetate extract of fungal mycelium which were cultured in sawdust could exhibit potential antioxidant activities. Keywords: Antioxidant activity Ethyl acetate Flavonoids Phenolics Sawdust Wood decay fungi