Dataset Information

The unravelling of the complex pattern of tyrosinase inhibition.

ABSTRACT: Tyrosinases are responsible for melanin formation in all life domains. Tyrosinase inhibitors are used for the prevention of severe skin diseases, in skin-whitening creams and to avoid fruit browning, however continued use of many such inhibitors is considered unsafe. In this study we provide conclusive evidence of the inhibition mechanism of two well studied tyrosinase inhibitors, KA (kojic acid) and HQ (hydroquinone), which are extensively used in hyperpigmentation treatment. KA is reported in the literature with contradicting inhibition mechanisms, while HQ is described as both a tyrosinase inhibitor and a substrate. By visualization of KA and HQ in the active site of TyrBm crystals, together with molecular modeling, binding constant analysis and kinetic experiments, we have elucidated their mechanisms of inhibition, which was ambiguous for both inhibitors. We confirm that while KA acts as a mixed inhibitor, HQ can act both as a TyrBm substrate and as an inhibitor.

SUBMITTER: Deri B

PROVIDER: S-EPMC5057104 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The unravelling of the complex pattern of tyrosinase inhibition.

Deri Batel B Kanteev Margarita M Goldfeder Mor M Lecina Daniel D Guallar Victor V Adir Noam N Fishman Ayelet A

Scientific reports 20161011

Tyrosinases are responsible for melanin formation in all life domains. Tyrosinase inhibitors are used for the prevention of severe skin diseases, in skin-whitening creams and to avoid fruit browning, however continued use of many such inhibitors is considered unsafe. In this study we provide conclusive evidence of the inhibition mechanism of two well studied tyrosinase inhibitors, KA (kojic acid) and HQ (hydroquinone), which are extensively used in hyperpigmentation treatment. KA is reported in ...[more]

PMID: 27725765

Similar Datasets

Project description:When exposed to ultraviolet radiation, the human skin produces profuse reactive oxygen species (ROS), which in turn activate a variety of biological responses. Mounting ROS levels activate tyrosinase by mobilizing ?-melanocyte-stimulating hormone in the epidermis and finally stimulates the melanocytes to produce melanin. Meanwhile, the Keap1-Nrf2/ARE pathway, which removes ROS, is activated at increased ROS levels, and antioxidant compounds facilitates the dissociation of Nrf2. In this study, we explored the possible suppressing effects of antioxidant compounds and tyrosine inhibitors on melanin formation and the promotory effects of these compounds on ROS scavenging. The antioxidant activity of glabridin (GLA), resveratrol (RES), oxyresveratrol (OXYR), and phenylethylresorcinol (PR) were investigated via the stable free radical 2,2-diphenyl-1-picrylhydrazyl method. The inhibitory effects of the four compounds and their mixtures on tyrosinase were evaluated. l-Tyrosine or 3-(3,4-dihydroxyphenyl)-l-alanine (l-DOPA) was used as a substrate. The results showed that all mixtures did not exhibit synergistic effects with the l-tyrosine as a substrate, suggesting that l-tyrosine is not suitable as a substrate. However, the mixtures of "GLA:RES," "GLA:OXYR," "OXYR:RES," and "PR:RES" demonstrated synergistic effects (CI < 0.9, p < 0.05), whereas "GLA:RES" and "PR:OXYR" indicated an additive effect (0.9 ditive1, p < 0.05). Furthermore, we used a molecular docking strategy to study the interactions of the four compounds with tyrosinase and l-DOPA. The molecular docking result is consistent with that of the experiment. Finally, we selected RES + OXYR and used PIG1 cells to verify whether OXYR synergistically promotes RES activity on tyrosinase. The two agents had a synergistic inhibitory effect on tyrosinase activity. These results provided a novel synergistic strategy for antioxidants and tyrosinase inhibitors, and this strategy is useful in skin injury treatment.

Project description:Melanin deposition is the main cause of skin darkening, which can lead to severe physical and psychological distress, necessitating the development of approaches for preserving skin health and fairness. Tyrosinase (TYR) is the rate-limiting enzyme in melanin synthesis, and its activity directly determines the degree of melanin accumulation in the skin, which in turn affects skin color. Currently, TYR inhibitors derived from natural products are widely used for skin whitening. San-Bai decoction (SBD) is effective for skin whitening and softening, but its mechanism of action, efficacy and high efficiency TYR inhibitors for skin whitening remain poorly understood. Here, we employed systems biology and network pharmacology to analyze the active compounds and targets of SBD, using the follow databases: TCMIP, TCMID, and BATMAN-TCM. Construct a molecular network centered on the regulation of TYR by SBD in skin whitening, using STRING database and cytoscape. Enrichment analysis using KOBAS database and ClusterProfiler. Virtual screening of candidate TYR inhibitors using Molecular Operating Environment software and Amber 18 software. SBD may act through tyrosine metabolism, melanogenesis, and other signaling pathways to regulate TYR activity and inhibit melanogenesis. We identified TYR and ESR1 as possible key targets for the whitening effect of SBD and screened out pentagalloylglucose, 1,3,6-tri-O-galloyl-beta-D-glucose, 1,2,4,6-tetragalloylglucose, and liquiritigenin 4',7-diglucoside as inhibitors of TYR, in addition to glycyrrhizic acid, pachymic acid methyl ester, nicotiflorin, gamma-sitosterol, and isoliensinine as inhibitors of ESR1. We also performed virtual drug screening of a library of natural small-molecule compounds (19,505 in total) and screened out lycopsamine, 2-phenylethyl b-D-glucopyranoside, and 6-beta-hydroxyhyoscyamine as inhibitors of TYR. We identified natural compounds with the potential for skin whitening through inhibition of TYR, thus advancing research on SBD and its applications.

Dataset Information

The unravelling of the complex pattern of tyrosinase inhibition.

Publications

The unravelling of the complex pattern of tyrosinase inhibition.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets