Anti-Tyrosinase activity of protein hydrolysate from chicken feather meal prepared by pepsin-pancreatin and papain

Abstract

Tyrosinase is a copper containing enzyme which catalyzes the first two stages of mammalian melanogenesis. Tyrosinase inhibitors are important for their potential application in skin-whitening products. This study investigated the tyrosinase inhibitory properties of protein hydrolysates prepared from chicken feather meal using pepsin-pancreatin and papain hydrolysis. The protein hydrolysates were prepared and fractionated by ultrafiltration membrane. Protein hydrolysates prepared by pepsin-pancreatin with MW < 3 kDa exhibited strong tyrosinase inhibition activity for both monophenolase (IC₅₀ 5.780 ± 0.188 µg/ml) and diphenolase (IC₅₀ 0.040 ± 0.024 µg/ml) in a cell-free mushroom tyrosinase system and were found to be uncompetitive inhibitors with Ki values of 18.149 and 27.189 µg/ml in monophenolase and diphenolase activities, respectively. A cell culture model showed that protein hydrolysates prepared by pepsin-pancreatin with MW < 3 kDa had the strongest inhibition on the viability of B16F10 cells (IC₅₀ 1.124 ± 0.288 µg/ml) and good inhibition on their tyrosinase activity. The addition of protein hydrolysates at a concentration of 0.210 µg/ml to B16F10 cells inhibited tyrosinase activity by 50.493 % and melanin synthesis by 14.680 % compared to the control without protein hydrolysates. Protein hydrolysates in the MW < 3 kDa fraction were selected for further study regarding apoptosis detection assays, and purification of tyrosinase inhibitor peptides by RP-HPLC; these peptides were identified by LC/MS/MS analysis. Tyrosinase inhibitors from protein hydrolysates have potential application as materials for skin whitening products.