Tyrosinase Inhibitory Effect and Antioxidative Activities of Fermented and Ethanol Extracts ofRhodiola roseaandLonicera japonica

Abstract

This is the first study to investigate the biological activities of fermented extracts ofRhodiola roseaL. (Crassulaceae) andLonicera japonicaThunb. (Caprifoliaceae).Alcaligenes piechaudiiCC-ESB2 fermented and ethanol extracts ofRhodiola roseaandLonicera japonicawere prepared and the antioxidative activities of different concentrations of samples were evaluated usingin vitroantioxidative assays. Tyrosinase inhibition was determined by using the dopachrome method with L-DOPA as substrate. The results demonstrated that inhibitory effects (ED50values) on mushroom tyrosinase of fermentedRhodiola rosea, fermentedLonicera japonica, ethanol extract ofLonicera japonica,and ethanol extract ofRhodiola roseawere 0.78, 4.07, 6.93, and >10 mg/ml, respectively. The DPPH scavenging effects of fermentedRhodiola rosea(ED50= 0.073 mg/ml) and fermentedLonicera japonica(ED50= 0.207 mg/ml) were stronger than effects of their respective ethanol extracts. Furthermore, the scavenging effect increases with the presence of high content of total phenol. However, the superoxide scavenging effects of fermentedRhodiola roseawas less than effects of fermentedLonicera japonica. The results indicated that fermentation ofRhodiola roseaandLonicera japonicacan be considered as an effective biochemical process for application in food, drug, and cosmetics.