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.