Anti-Oxidant Property and Inhibition of Melanin Synthesis of Eight Plant Extracts

Plants extracts are good resources to find functional compounds for human health. The following eight plants were collected and total phenolic contents were determined. Acer psedo-siebolianum showed the highest phenolic contents, 16.4 mg/g, whereas Cercidiphyllum japonica showed the lowest contents, 1.9 mg/g. The DPPH free radical scavenging capacities of the plant extracts showed high activity in following order : Acer ginnala (21.3 μg/mL) > Cornus walteri (23.9 μg/mL) > Distylum racemosum (29.2 μg/mL) > Castanopsis cuspidata var. Thunbergii (31.7 μg/mL) > Acer psedo-siebolianum (34.6 μg/mL) > Thuijopsis dolabrata cv. Aurea (53.1 μg/mL) > Cercidiphyllum Japonica (115.2 μg/mL). Also the mushroom tyrosinase inhibitory activities of total extracts were determined at different concentration. D. racemosum extract showed highest (49.1% at 1,000 mg) in inhibitory activity than other seven extracts. The ethanol fraction (IC50 value: 118.1 μg/mL) from D. racemosum showed more inhibitory activity than ethyl acetate fraction (IC50 value: 203 μg/mL). The ethanol fraction on showed no significant cytotoxicity in B16/F1 cells line up to 60 μg/mL. Over 80 μg/mL of ethanol fraction showed cytotoxicity in B16/F1 cells. The melanin contents of cells were significantly attenuated by ethanol fraction in a dose-dependent manner. The IC50 value of ethanol fraction was 75.4 μg/mL.