The influence of samples on the activity of mushroom TYR (MTYR) and TYR extracted from animal cells are commonly used indicators for the preliminary screening of samples with potential anti-melanogenic activity. Even in different organs and tissues of the same species, TYR has different functions. In addition, the nucleic acid sequence and protein molecular structure of TYR belonging to different species are different. For example, their molecular weight (about 53 kD to 75 kD of different species) and isoelectric point have a wide range of changes. TYRs have similar physiological functions in vivo, but their physical and chemical properties are different. TYR is widely found in bacteria, fungi, plants and animals. Compared with the unstable β-arbutin, EGCG was more valuable for clinical research. In conclusion, the TYR inhibitory activities of samples were affected by enzyme species and sample addition methods. The TYR inhibitory activity of β-arbutin was complicated and fickle, while that of epigallocatechin gallate (EGCG) was universal and stable, which is to say, EGCG always inhibited TYR activity in a dose-dependent manner. Additionally, kojic acid could be used as a positive control for both B16F10 cells and MTYR models. It was speculated that indirectly inhibitory activity reflected the comprehensive effects of samples on TYR catalytic activity and intracellular TYR synthesis pathway, while directly inhibitory activity reflected the effects of samples on TYR catalytic activity. It was necessary to select the appropriate enzyme according to the problems to be explained.

Results showed that TYR inhibitory activities of samples were obviously affected by the above two factors.

TYRs extracted from B16F10 cells, apple and mushroom, called BTYR, ATYR and MTYR, respectively, were selected to implement this study. Under the same experimental conditions, this paper systematically studies whether enzyme species and sample addition methods are the key factors that determine the TYR inhibitory activity of samples.

At present, there are many methods with discrepant details that study the TYR inhibitory activity of samples. The inhibition of tyrosinase (TYR) activity is an effective measure to inhibit melanin synthesis.

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