초록
영어
The current investigation was undertaken to evaluate the antioxidant activities, tyrosinase inhibitory effects on the fruiting bodies of P. ostreatus extracted with acetone, methanol and hot water. The antioxidant activities were performed on β-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging, and ferrous chelating abilities. In addition to this, phenolic acid and flavonoids contents were also analyzed. Methanolic extract of P. ostreatus showed the strongest β-carotene-linoleic acid inhibition as compare to others exracts. At 8 mg/ml, acetonic extract showed a high reducing power of 1.54. The scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals, acetonic extract was effective than other extracts. The strongest chelating effect (85.66%) was obtained from the acetonic extract at 1.0 mg/ml concentration. Antioxidant activities of the extracts from the fruiting bodies of P. ostreatus were increased with the increasing concentration. After application of reverse phase high performance liquid chromatography, coupled to a diode array detector and electrospray ionisation mass spectra, six phenolic compounds namely, gallic acid, protocatechuic acid, naringenin, hesperetin, formononetin and biochanin were identified from acetonic extract. Tyrosinase inhibition of acetonic, methanolic, and hot water extracts of P. ostreatus were increased with the increasing of concentration. Results revealed that methanolic extract showed good, while acetonic and hot water extracts showed moderate activities of the tyrosinase inhibition at the concentration tested. This study suggests that fruiting bodies of P. ostreatus can potentially be used as a readily accessible source of natural antioxidants.