3.4. In Vitro Mushroom Tyrosinase Activity

Mushroom tyrosinase (EC 1.14.18.1, Sigma-Aldrich) was dissolved in 1/15 M PBS (pH 6.8) to a concentration of 276 units/mL and used. About 150 μL of Mushroom Tyrosinase (13.8 units/mL) was reacted with L-tyrosine (T−3754, Sigma-Aldrich) and cycloheterophyllin (10, 1, 0.1 ug/mL) for 5 min, and the absorbance was measured at a wavelength of 475 nm. Each experimental group was independently tested three times, and the tyrosinase enzyme inhibition rate (%) of the material was calculated by applying the following calculation formula. As a positive control, kojic acid (K3125, Sigma-Aldrich) at a concentration of 100 μg/mL was used.

Tyrosinase inhibition ratio (%) = (1 − absorbance of treatment/absorbance of non-treatment) × 100