Tyrosinase activity was determined by L-DOPA oxidation. A. Stimulation of tyrosinase activity of B16 cell by KZE at 5-40 μg /ml. B. Melanin content were performed as described in "Materials and methods", B16 cells, the same by KZE at 5-40 μg /ml.MOP being positive controls at 50 μM. Results shown are means ± SEM and are representative of three independent experiments. Data were analyzed by One-Way Analysis of Variance (ANOVA) followed by post hoc Tukey test. **P<0.01, compared with control.