Free radical-scavenging and inhibition of nitric oxide production by four grades of pine mushroom (Tricholoma matsutake Sing.)

Fractions from methanol extracts of four grades of pine mushroom (Tricholoma matsutake Sing.) were evaluated for their free radical-scavenging and inhibition of nitric oxide production, and the underlying mechanisms were elucidated. The fractions from first-grade pine mushroom exhibited the highest degree of free radical-scavenging and inhibition of nitric oxide production among the various grades of mushroom tested, and free radical-scavenging and inhibition of nitric oxide production by the second-, third-, and fourth-grade mushroom fractions were successively lower. The degree of free radical-scavenging by each fraction decreased in the order ethyl acetate > butanol > diethyl ether > water. Inhibition of nitric oxide production by each fraction decreased in the order ethyl acetate > butanol > water. The ethyl acetate and butanol fractions of methanol-extracted pine mushroom samples exhibited potential anti-oxidative and anti-inflammatory effects that might be attributable to phenolics or flavonoids.