Abstract: Synergistic action of joint application of glabridin,3-O-ethyl-L-ascorbic acid and nicotinamide on tyrosinase activity was investigated using the tyrosinase cell-free system and B16 melanoma cell model.Results showed that in both systems,glabridin displays the highest tyrosinase inhibition efficacy.Via orthogonal designed experiment,action of glabridin in blends of the three kinds of whitening agent on inhibition of tyrosinase activity is identified as the highest.Further test with tyrosinase cell-free system and B16 melanoma system proved that joint use of glabridin of mass concentration 3.125 mg·L^-1 with nicotinamide and 3-O-ethyl-L-ascorbic acid of separate mass concentrations can significantly enhance the inhibitory effect on tyrosinase activity.Comparison of experimental results showed that the blend of glabridin and nicotinamide displays the maximum synergistic inhibition action on tyrosinase activity as well as the best whitening efficacy.

Key words: whitening agent, glabridin, nicotinamide, 3-O-ethyl-L-ascorbic acid, tyrosinase