Inhibitory Effect of Gnetin C, a Resveratrol Dimer from Melinjo (Gnetum gnemon), on Tyrosinase Activity and Melanin Biosynthesis

The purpose of this study was to determine the inhibitory action of protocatechuic aldehyde (PCA) on tyrosinase activity. PCA is one of the compounds found in the root of Salvia miltiorrhiza. Our study documented that PCA has a potent inhibitory effect on tyrosinase, which catalyzes the rate-limiting step of melanin biosynthesis. Although melanin biosynthesis has an essential function normally in human skin for defense against ultraviolet light of the sun, its abnormal activity as seen in pigmentation disorder could lead to serious medical problems. Our data showed that PCA, with concentrations ranging from 1×10-5 M to 8×10-5 M , exhibited dose-dependent inhibition of the enzyme activity with 50% of inhibition at 19.92×10-6 M . A further kinetic analysis on PCA inactivation of tyrosinase activity revealed a competitive inhibition of the enzyme at the L-tyrosine binding site. The findings of our present study merit further research on the applicability of PCA as a potential agent for treatment of pigmentation disorder.

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Anti-Melanogenic Activity of p-Chlorophenyl Benzyl Ether in α-MSH-Induced Mouse Melanoma B16F10 Cells

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.819.118 ◽

2019 ◽

Vol 819 ◽

pp. 118-123

Author(s):

Wassana Riam-Amatakun ◽

Panupan Limpachayaporn ◽

Jhoan Rhea L. Pizon ◽

Praneet Opanasopit ◽

Nopparat Nuntharatanapon

Keyword(s):

Kojic Acid ◽

Positive Association ◽

Inhibitory Effect ◽

Tyrosinase Activity ◽

Dependent Manner ◽

Benzyl Ether ◽

Melanin Content ◽

Synthetic Compound ◽

Melanin Biosynthesis ◽

B16f10 Cells

Melanin is cutaneous pigment which level of its production determines skin complexion. Overproduction of melanin, frequently promoted by UV rays, results in darkening of the skin. Inhibition of tyrosinase activity, a core component in melanin biosynthesis, is one of the mechanisms of depigmenting agents. Hydroquinone and kojic acid are the examples of well-known whitening agents widely used in both pharmaceutical and cosmetic products. However, their adverse effect issues still needed to be overcome. A recent study showed that p-chlorophenyl benzyl ether (Cl-benz), a new synthetic compound, more strongly inhibited mushroom tyrosinase than kojic acid. In the current study, cytotoxicity, anti-melanogenic activity and anti-tyrosinase activity of Cl-benz were performed in mouse B16F10 melanoma cells compared to kojic acid. After 24 h of treatment on B16F10 cells, the cytotoxicity was not observed with Cl-benz and kojic acid. However, after incubation for 48 h, kojic acid at a concentration of 500 μM reduced cell viability less than 50%, whereas Cl-benz-treated cells showed negligible cytotoxicity. For cell-based assay, Cl-benz exhibited inhibitory effect similar to kojic acid. Melanin production in B16F10 cells was suppressed by Cl-benz in a dose dependent manner. One hundred micrograms of Cl-benz decreased melanin content in α-MSH by 66%. Moreover, the percentage of cellular tyrosinase activity of Cl-benz showed positive association with its corresponding melanin content. These results revealed that Cl-benz could inhibit melanogenesis via the mechanism of cellular tyrosinase inhibition. Accordingly, Cl-benz has potential to become a novel skin whitening agent in terms of efficacy and safety.

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Antityrosinase activity ofEuphorbia characiasextracts

PeerJ ◽

10.7717/peerj.1305 ◽

2015 ◽

Vol 3 ◽

pp. e1305 ◽

Cited By ~ 19

Author(s):

Francesca Pintus ◽

Delia Spanò ◽

Angela Corona ◽

Rosaria Medda

Keyword(s):

Competitive Inhibition ◽

Ethanolic Extract ◽

Inhibitory Effect ◽

Cellular Systems ◽

Tyrosinase Activity ◽

Dependent Manner ◽

Mushroom Tyrosinase ◽

Leaf Extracts ◽

Melanin Biosynthesis ◽

Ethanolic Extracts

Tyrosinase is a well-known key enzyme in melanin biosynthesis and its inhibitors have become increasingly important because of their potential use as hypopigmenting agents. In the present study, the anti-melanogenic effect of aqueous and ethanolic extracts fromEuphorbia characiasleaves, stems, and flowers in cell-free and cellular systems was examined. All the extracts showed inhibitory effects against mushroom tyrosinase with leaf extracts exhibiting the lowest IC50values of 24 and 97 µg/mL for aqueous and ethanolic extracts respectively. Enzyme kinetic analysis indicated that leaf aqueous extract acts as a mixed type inhibitor, while ethanolic extract shows a competitive inhibition effect on mushroom tyrosinase using L-DOPA as substrate. In addition, the inhibitory effect of leaf extracts on tyrosinase activity and melanin production was examined in murine melanoma B16F10 cells. Cellular tyrosinase activity as well as levels of melanin synthesis are reduced in a dose-dependent manner by extracts in cells treated withα-melanocyte stimulating hormone (α-MSH). The effects are comparable, and sometimes even better, than that of kojic acid, a well known tyrosinase inhibitor used for reference. All these results suggest thatE. characiascould be a great source of the natural inhibitors from tyrosinase and has the potential to be used as a whitening agent in therapeutic fields.

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Inhibitory Effect of 2,4,2′,4′-Tetrahydroxy-3-(3-methyl-2-butenyl)-chalcone on Tyrosinase Activity and Melanin Biosynthesis

Biological and Pharmaceutical Bulletin ◽

10.1248/bpb.32.86 ◽

2009 ◽

Vol 32 (1) ◽

pp. 86-90 ◽

Cited By ~ 41

Author(s):

Xiaodong Zhang ◽

Xiao Hu ◽

Aijun Hou ◽

Heyao Wang

Keyword(s):

Inhibitory Effect ◽

Tyrosinase Activity ◽

Melanin Biosynthesis

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The inhibitory effect of pyrogallol on tyrosinase activity and structure: Integration study of inhibition kinetics with molecular dynamics simulation

International Journal of Biological Macromolecules ◽

10.1016/j.ijbiomac.2018.10.046 ◽

2019 ◽

Vol 121 ◽

pp. 463-471 ◽

Cited By ~ 7

Author(s):

Shang-Ling Xiong ◽

Gyu Tae Lim ◽

Shang-Jun Yin ◽

Jinhyuk Lee ◽

Yue-Xiu Si ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Inhibitory Effect ◽

Tyrosinase Activity ◽

Dynamics Simulation ◽

Inhibition Kinetics

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Molecular characterization of prophenoloxidase-1 (PPO1) and the inhibitory effect of kojic acid on phenoloxidase (PO) activity and on the development ofZeugodacus tau(Walker) (Diptera: Tephritidae)

Bulletin of Entomological Research ◽

10.1017/s0007485318000470 ◽

2018 ◽

Vol 109 (2) ◽

pp. 236-247 ◽

Cited By ~ 2

Author(s):

H.-H. Zhang ◽

M.-J. Luo ◽

Q.-W. Zhang ◽

P.-M. Cai ◽

A. Idrees ◽

...

Keyword(s):

Kojic Acid ◽

Normal Growth ◽

Competitive Inhibitor ◽

Inhibitory Effect ◽

Pupal Weight ◽

Mrna Levels ◽

Melanin Biosynthesis ◽

Horticultural Pest ◽

Inhibition Experiment

AbstractPhenoloxidase (PO) plays a key role in melanin biosynthesis during insect development. Here, we isolated the 2310-bp full-length cDNA of PPO1 fromZeugodacus tau, a destructive horticultural pest. qRT-polymerase chain reaction showed that theZtPPO1transcripts were highly expressed during larval–prepupal transition and in the haemolymph. When the larvae were fed a 1.66% kojic acid (KA)-containing diet, the levels of theZtPPO1transcripts significantly increased by 2.79- and 3.39-fold in the whole larvae and cuticles, respectively, while the corresponding PO activity was significantly reduced; in addition, the larval and pupal durations were significantly prolonged; pupal weights were lowered; and abnormal phenotypes were observed. Anin vitroinhibition experiment indicated that KA was an effective competitive inhibitor of PO inZ. tau. Additionally, the functional analysis showed that 20E could significantly up-regulate the expression ofZtPPO1, induce lower pupal weight, and advance pupation. Knockdown of theZtPPO1gene by RNAi significantly decreased mRNA levels after 24 h and led to low pupation rates and incomplete pupae with abnormal phenotypes during the larval-pupal interim period. These results proved that PO is important for the normal growth ofZ. tauand that KA can disrupt the development of this pest insect.

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Anti-Melanogenic Effects of Hydroxyectoine via MITF Inhibition by JNK, p38, and AKT Pathways in B16F10 Melanoma Cells

Natural Product Communications ◽

10.1177/1934578x19858523 ◽

2019 ◽

Vol 14 (6) ◽

pp. 1934578X1985852 ◽

Cited By ~ 1

Author(s):

You C. Chung ◽

Min-Jin Kim ◽

Eun Y. Kang ◽

Yun B. Kim ◽

Bong S. Kim ◽

...

Keyword(s):

Skin Color ◽

Inhibitory Effect ◽

Tyrosinase Activity ◽

Dependent Manner ◽

Related Protein ◽

B16f10 Melanoma ◽

Melanin Production ◽

B16f10 Cells ◽

Dose Dependent ◽

Tyrosinase Related Protein

Melanin plays a role in determining human skin color of a person, and a large amount of melanin makes the skin color look darkened. The proper amount of melanin formation protects our skin from UV radiation, but excessive melanin production causes hyperpigmentation and leads to freckles, melasma, and lentigo. In this study, we investigated the inhibitory effect of hydroxyectoine on melanogenesis and its mechanism in B16F10 cells. Melanin content and cellular tyrosinase activity were determined. The expression of microphthalmia-associated transcription factor (MITF), and the activities of tyrosinase and other melanogenesis-related enzymes, such as tyrosinase-related protein 1 (TRP-1) and tyrosinase-related protein 2, were also examined. Hydroxyectoine treatment significantly inhibited melanin production and intracellular tyrosinase activity in a dose-dependent manner. Western blot analysis showed that hydroxyectoine also reduced the expressions of tyrosinase and TRP-1. In addition, hydroxyectoine significantly reduced the expression of MITF, a major regulator of melanin production, and inhibited the phosphorylation of p38, c-Jun N-terminal kinase, and activated the protein kinase B. The results demonstrated that hydroxyectoine inhibits the expression of MITF through the inhibition or activation of melanin-related signaling pathways and downregulates melanogenesis by inhibiting melanogenic enzyme expression and tyrosinase activity. Hydroxyectoine has potential value in functional cosmetics applications, such as whitening.

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Optimization of Flavonoid Extraction in Dendrobium officinale Leaves and Their Inhibitory Effects on Tyrosinase Activity

International Journal of Analytical Chemistry ◽

10.1155/2019/7849198 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Haixia Lu ◽

Ke Yang ◽

Lianghui Zhan ◽

Tingting Lu ◽

Xue Chen ◽

...

Keyword(s):

Ethanol Concentration ◽

Inhibitory Effect ◽

Tyrosinase Activity ◽

Dendrobium Officinale ◽

Key Factors ◽

Extraction Technology ◽

Steepest Ascent ◽

Burman Design ◽

Solid Liquid

In order to establish the extraction technology of flavonoids from Dendrobium officinale leaves, a method combining Plackett–Burman design (PBD), steepest ascent design, and central composite design was developed to optimize the extraction of flavonoids. In addition, the tyrosinase activity inhibition of flavonoids was further tested in vitro. PBD results showed that ethanol concentration and number of extractions were key factors. Response surface methodology (RSM) indicated that the optimal extraction conditions were 78% ethanol concentration, six extraction times, 2 h, and 1:50 solid-liquid ratio. Under these conditions, the total flavonoid content could reach 35 mg/50 mL. In vitro tyrosinase experiment, the extracted total flavonoids had better inhibitory effect on tyrosinase activity than β-arbutin, and its inhibition rate for monophenolase and diphenolase exceeded 100% and 70%, respectively. These results indicate that RSM can effectively improve the extraction of flavonoids from Dendrobium officinale leaves and the flavonoids have the prospect of being applied to foods and cosmetics.

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