Evaluation of the antioxidant and antityrosinase activities of three extracts from <i>Pleurotus nebrodensis</i> fruiting bodies

Abstract

Pleurotus nebrodensis has been widely used for nutritional and medicinal purposes. The aim of the present study was to evaluate the antioxidant activities and tyrosinase inhibitory effects on the fruiting bodies of P. nebrodensis extracted with acetone, methanol and hot water. The antioxidant activities were performed on - carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferrous ions chelating abilities and xanthine oxidase inhibitory activity. In addition to this, phenolic compounds were also detected. The acetonic and methanolic extracts of P. nebrodensis showed the strongest -carotene-linoleic acid inhibition as compare to hot water extract. At 8 mg/ml, the acetonic extract showed a high reducing power of 1.86. The scavenging activity on DPPH radicals, the acetonic and methanolic extracts were effective than that of hot water extract. At lower concentrations, chelating effect of tested mushroom was significantly effective as compare to positive control. Gallic acid, protocatechuic acid, chlorogenic acid, ferulic acid, naringenin, hesperetin, formononetin and biochanin-A were detected from acetonitrile and hydrochloric acid solvent extract. The xanthine oxidase and tyrosinase inhibitory activities of the acetonic, methanolic and hot water extracts increased with increase of concentration. This study suggests that fruiting bodies of P. nebrodensis can potentially be used as a readily accessible source of natural antioxidants.

Key words: Antioxidant, phenolic compounds, Pleurotus nebrodensis, tyrosinase inhibition, xanthine oxidase.