Antioxidant and radical scavenging properties of extracts from Ganoderma tsugae

The antioxidant activities and scavenging effects on free radicals of extracts from Ganoderma were investigated. The methanolic extracts of Ganoderma tsugae (MEGT) showed the strongest antioxidant activity of five species of Ganoderma tested. MEGT exhibited substantial antioxidant activity in the linoleic acid and rat liver microsome peroxidation systems. The antioxidant activity of MEGT was stronger than α-tocopherol. MEGT had a strong chelating effect on Fe²⁺. MEGT showed a marked and concentration-dependent scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl radical. MEGT also exhibited a strong scavenging effect on the hydroxyl radical as measured by electron paramagnetic resonance spectrometry. The formation of 8-hydroxy-2′-deoxyguanosine, from 2′-deoxyguanosine induced by various prooxidants, was reduced by MEGT. In view of these results, the antioxidant and radical scavenging activities of Ganoderma may have an important role on inhibition of lipid peroxidation in biological systems.