Evaluation of antityrosinase activity and mechanism, antioxidation, and UV filter properties of theaflavin

Abstract

Tyrosinase is a key metalloenzyme for the biosynthesis of melanin that plays a critical role in the prevention of skin damage caused by ultraviolet (UV) radiation. However, the overproduction of melanin may cause a variety of skin diseases. Due to the toxicity and inefficiency of existing tyrosinase inhibitors, it is urgent to identify safe and potent alternatives from natural sources. Theaflavin, a single-component extracted from black tea, has been found to possess a variety of pharmacological activities. Herein, the inhibition kinetics of theaflavin on tyrosinase and inhibitory mechanism were determined using spectroscopy, molecular docking, and zebrafish model. The results showed that theaflavin inhibited the diphenolase activity of tyrosinase in a reversible mixed type manner with IC 50 of 229.75 μmol/L and hindered the synthesis of melanin in zebrafish. This may be due to the formation of eight hydrogen bonds and hydrophobic effects between theaflavin and tyrosinase according to the results of molecular docking. To study the possible effects on the prevention of free radical-mediated skin cancer and photoaging caused by UV radiation, the antioxidation and UV filter properties of theaflavin were further verified. This study demonstrates that theaflavin is a potential multifunctional compound that can be used in cosmetic and medicinal products.

Inhibitory Activities of Samples on Tyrosinases Were Affected by Enzyme Species and Sample Addition Methods

“…Based on these results, it was speculated that EGCG was a competitive inhibitor of MTYR ( Figure 5 a,e). With the increase in kojic acid concentration, K m increased and V max decreased, and the intersection of the lines was in the second quadrant, indicating that kojic acid was a mixed (competitive-noncompetitive) inhibitor of MTYR ( Figure 5 a,e) [ 20 ].…”

Response of Thymus lotocephalus In Vitro Cultures to Drought Stress and Role of Green Extracts in Cosmetics

“…Since MeJA extract showed the highest ability to absorb UV radiation, the sun protection factor (SPF) was only calculated for this extract at different concentrations (50, 250, 750, 1500, and 2500 µg/mL). Compared to the in vivo models for the determination of SPF, the in vitro models present several advantages since they are simple, reproducible, fast, and avoid subject UV exposure [ 91 ]. The UV radiation in the range of 290–320 nm retains the highest biological activity to induce skin damage, such as burning, photoaging, and cancer, so the SPF of a product is evaluated in these wavelengths.…”

Synthesis and molecular modeling of new 2‐benzylidenethiobarbituric acid derivatives as potent tyrosinase inhibitors agents

“…Tyrosinase is a metalloenzyme containing two copper atoms that play a critical biological role in the process of melanogenesis in various organs. [ 1 ] Melanogenesis refers to the processes that eventually lead to the formation of melanin pigments. There are two forms of melanin pigment in mammalian bodies: pheomelanin and eumelanin, which are responsible for the dark‐brown and red–pink color of the skin, respectively.…”

“…melanogenesis: (1) the hydroxylation of tyrosine to 3,4dihydroxyphenylalanine (DOPA), (2) oxidation of DOPA to DOPA quinone, and (3) oxidation of 5,6dihydroxyindole to indolequinone. [3] The most important role of melanin is the protection of the skin against damage from harmful Ultraviolet (UV) rays.…”

“…[6] Most of the commercially available skin lightening agents are tyrosinase inhibitors. [7] Many tyrosinase inhibitors such as hydroquinone (1), tretinoin (2), L-ascorbic acid (3), and kojic acid (4) have been used as skin-whitening agents, with certain drawbacks (Scheme 1). Each of these compounds has its advantages and disadvantages.…”