Antioxidant activities of extracts from the genus Phellinus species.

Ethanolic extracts of fruit bodies of five species (eight strains) of the genus Phellinus, and five solvent extracted fractions derived from one of these extracts (Ph. baumii PB-10), were evaluated for antioxidant activity and the capacity to protect PC12 cells against H2O2-induced oxidative damage. Extracts of all eight strains of Phellinus spp. exhibited antioxidant activity and protected PC12 cells against oxidative damage at different magnitudes of potency. Strongest antioxidant activity was exhibited by extracts of Ph. baumii PB-10, with recorded IC50 values for superoxide radical and hydrogen peroxide scavenging activity of 3.76 μg/mL and 4.24 μg/mL, respectively. Radical scavenging activities, reducing potential and anti-lipid peroxidation capability of five different extracts (petroleum ether, chloroform, ethyl acetate, n-BuOH and ethanol-petroleum phase ) derived from Phellinus baumii were studied. The results showed the ethyl acetate and nBuOH extracts exhibited stronger antioxidant capacity. Radical-scavenging activity and protection levels against H2O2-induced damage to PC12 cells were highly correlated with the flavonoid content of the extracts and isolated fractions.