Antioxidant and Skin Whitening Effects of Rhamnus yoshinoi Extracts

The purpose of this study was to investigate the antioxidant and skin whitening effects of Rhamnus yoshinoi extracts. Rhamnus yoshinoi was extracted with 100% ethanol and water. The antioxidative and skin whitening effects of extracts were determined by in vitro assays using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and inhibitory effects against tyrosinase activity and melanogenesis in B16F1 melanoma cells. The radical scavenging activities of the Rhamnus yoshinoi extracts were tested by DPPH assay and showed high DPPH radical scavenging activities (SC50; 21.6 ppm in EtOH, 40.5 ppm in water). As for tyrosinase inhibitory activity, the Rhamnus yoshinoi ethanol extract had the highest inhibition activity (IC50; 256.3 ppm). In B16F1 mouse melanoma cells, the Rhamnus yoshinoi ethanol extract significantly inhibited melanin synthesis by 53.36% at the concentration of 50 ppm. These results suggest that Rhamnus yoshinoi ethanol extract has significant antioxidant activity and whitening activity.