Antioxidant activity of extracts from the fruiting bodies of Agrocybe aegerita var. alba

Antioxidant activity of the methanol crude extract and its fractions, isolated by liquid-liquid partition, from the fruiting bodies of Agrocybe aegerita, an edible mushroom, was evaluated by scavenging activity of 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) radical cation (ABTS+) and inhibition of lipid peroxidation of rat brain homogenate. The ethyl acetate (EA) fraction, which showed the most potent antioxidant activity in the above two assays, was further fractionated by a Sephadex LH-20 column into four subfractions (EA1-EA4). EA3 exhibited the strongest radical-scavenging activity in the ABTS+ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and showed a similar extent of in vitro inhibition of human LDL oxidation to caffeic acid. Significant correlation was found between the total phenolic content and the antioxidant activity (p<0.01) in the EA fraction and its subfractions.