• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.3 s.58
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• pp.153-160
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• 2006

We synthesized 2',4'-dimethoxyflavone and investigated the effects on melanogenesis. To determine the effects as a whitening agent, various in uitro tests were performed such as free radical scavenging activity, melanin assay, tyrosinase activity and expression of tyrosinase, TRP-1 and TRP-2 (western blot and RT-PCR) in Bl6 melanoma cells. 2',4'-Dimethoxyflavone showed neither free radical scavenging activities against 1,1- diphenyl -2-picrylhydrazvl (DPPH) radical and inhibition of mushroom tyrosinase activity, 2',4'-dimethoxyflavone significantly inhibited melanin production in B16 melanoma cells. 2',4'-Dimethoxyflavone treatment (48h) suppressed the biosynthesis of melanin up to 27% at $5{\mu}g/mL$ and reduced tyrosinase activity up to 20% at $5{\mu}g/mL$ in B16 melanoma cells. 2',4'-Dimethoxyflavone was also able to significantly inhibit tyrosinase and TRP-1 expression in protein and mRNA level. These results suggest that 2',4'-dimethoxyflavone inhibits melanin biosynthesis at the level of enzyme activity and protein mRNA expression B16 melanoma cells. Therefore, 2',4'-dimethoxyflavone may be useful as a new whitening agent in cosmetics.

• Journal of Life Science
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• v.30 no.10
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• pp.851-859
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• 2020

Saururus chinensis has white roots, leaves, and flowers and is known to have antibacterial activity and anti-cancer efficacy. The aim of this study was to investigate the effect of the ethyl acetate fraction of a methanol extract of Saururus chinensis (SCEA) on antioxidant activity and melanin synthesis. SCEA at 64 ㎍/ml showed 62% of the DPPH radical scavenging activity of vitamin C, and its reducing power was 33% greater than that of vitamin C. Tyrosinase activity was 26% higher and melanin synthesis was 44% higher in the presence of SCEA at 64 ㎍/ml than in a blank group in a dopa oxidation assay. MTT assay showed that SCEA displayed cytotoxicity above 0.5 ㎍/ml, and SCEA at 1 ㎍/ml increased melanin synthesis by 69% in live B16F1 cells. SCEA was also separated into 13 fractions by silica column chromatography, and fraction 2 (Fr. 2) showed the highest DPPH radical scavenging activity, reducing power, and melanin synthesis. SCEA also promoted melanin production in live cells. LC-MASS analysis showed that Fr.2 had a molecular weight of 239, and these findings suggest that SCEA could be available for the promotion of melanin synthesis in black hair.

• Journal of Life Science
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• v.19 no.1
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• pp.75-80
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• 2009

Melanogenesis is a physiological process that results in the synthesis of melanin pigments. Tyrosinase is a key enzyme for melanin biosynthesis, and hyperpigmentation disorders are associated with abnormal accumulation of melanin pigments, which can be improved by treatment with depigmenting agents. Among the possible melanin-reducing compounds, tyrosinase inhibitors are most promising for preventing and treating pigmentation disorder and are used as skin-whitening agents in the cosmetic industry. In the present study, the effects of fucoidan on melanogenesis and tyrosinase activity of B16F10 melanoma cells were investigated. Melanin synthesis and tyrosinase activity in B16F10 melanoma cells were decreased in a dose-dependent manner by fucoidan. Melanin production and tyrosinase activity in B16F10 melanoma cells stimulated by a-melanocyte stimulating hormone (a-MSH) were inhibited by fucoidan with a dose-dependent manner compared to control. Fucoidan inhibited tyrosinase activity of B16F10 melanoma cells with a dose-dependent manner as assessed by 3,4-dihydroxyphenylalanine (DOPA) staining. In conclusion, these findings indicate that fucoidan, which inhibit melanin synthesis and tyrosinase activity, is an effective skin-whitening agent.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.6
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• pp.812-817
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• 2012

This study was performed to investigate the antioxidant activities and the melanin inhibitory effects of Hippophae rhamnoides L. fruit extracts. Two in vitro methods were used; the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method to determine antioxidant activity and measurements of the inhibitory effects of tyrosinase activity to determine melanogenesis in B16/F10 melanoma cells. The radical scavenging activity of the extract was 56.0% at $700{\mu}g/mL$, similar to ascorbic acid (56.9%), in the DPPH assay. The tyrosinase inhibitory activity of the extract was 52.1% and 73.4% at 100 and $500{\mu}g/mL$, which is also similar to ascorbic acid. In B16/F10 mouse melanoma cells, the extract inhibited melanin synthesis by 56% at $500{\mu}g/mL$, a more prominent inhibition of melanin synthesis compared to extracts from arbutin. These results suggest that extracts from H. rhamnoides L. have antioxidant activity and skin-whitening effects; allowing their application in cosmetics as a natural product.

• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.145-150
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• 2010

To examine the antioxidative effect and melanogenesis of Nelumbo nucifera stamen (NNS) extract on hydrogen peroxide $H_2O_2$ induced cytotoxicity in cultured human skin melanoma cells (SK-MEL-3), cell adhesion activity (CAA), tyrosinase inhibitory activity and total amount of melanin synthesis were measured by colorimetric assay. In this study, $H_2O_2$ significantly decreased CAA, and $CAA_{50}$ value of $H_2O_2$ was determined at 30 uM. In the antioxidative effect, NNS extract increased cell adhesion activity which was decreased by $H_2O_2$ induced cytotoxicity, and also, tyrosinase activity and total amount of melanin were decreased by NNS extract. These results suggested that $H_2O_2$ was highly toxic on cultured human skin melanoma cells and NNS extract showed the antioxidative and inhibitory effect of melanogenesis by the increased CAA, and the decresed tyrosinase activity and total amount of melanin synthesis.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.4
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• pp.363-370
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• 2021

This study was conducted to evaluate the dermal cytotoxicity of lead acetate (LA) and other heavy metal compounds, and the protective effect of Lespedeza bicolor (LB) extract on LA-induced cytotoxicity in cultured B16-/F10 melanoma cells. The study evaluated the antioxidative effects of LB due to its electron-donating ability (EDA), inhibitory effects on melanization and improving cell viability. LA significantly decreased cell viability in a dose-dependent manner, and the XTT₅₀ value was determined at 52.7 µM in the studied cultures. Based on the Borenfreund and Puerner's toxicity criteria, LA was estimated to be highly cytotoxic. LA-induced cytotoxicity and cell damage was reversed by the antioxidant activity of kaempferol (KAE), thereby remarkably improving cell viability. A study of the protective effects of the LB extract on LA-induced cytotoxicity showed that the LB extract remarkably increased cell viability in the LA-treated group, and also inhibited the EDA and the total amount of melanin. The above results suggest oxidative stress-mediated cytotoxicity of LA. In the study, LB extract effectively prevented LA-induced cytotoxicity via its antioxidative activity and inhibition of melanization. In conclusion, natural resources like LB extracts may be useful agents for the prevention of oxidative stress-mediated cytotoxicity and melanization by heavy metallic compounds such as LA.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.463-470
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• 2020

The JS18 strain was isolated from an old tree forest and produced extracellular enzymes that decolorize synthetic melanin. Phylogenetic analysis, based on the internal transcribed spacer (ITS) sequence, indicate that JS18 belongs to the Trametes velutina species. JS18 demonstrated laccase activity but no manganese peroxidase or lignin peroxidase activity. Batch culture indicated that the melanin decolorization activity of JS18 strain originated from the laccase. Syringic acid and CuSO4 induced maximum laccase production, yielding 98 U/ml laccase activity after cultivation for 7 days at 25℃. T. velutina secretes an extracellular laccase in GYP medium, and this enzyme was purified using (NH4)2SO4 precipitation, Hi-trap Q Sepharose columns and gel filtration. The molecular weight of the purified enzyme was estimated to be 67 kDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis. This enzyme produced 80% of its melanin decolorization activity within the first 24 h of evaluation in the presence of 1-hydroxybenzotriazole (HBT), while only about 4% of the melanin was decolorized in the absence of the mediator. The greatest decolorization was observed at 1.5 mM/l HBT, which decolorized 81% of the melanin within the first 24 h. The optimum pH and temperature for this decolorization were found to be 5.0 and 37℃, respectively. Our results suggest the possibility of applying HBT induced T. velutina JS18 laccase-catalyzed melanin decolorization.

• Journal of Life Science
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• v.32 no.5
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• pp.331-339
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• 2022

Melanin is a pigment produced by melanocytes to protect the skin from external stimuli, mainly ultraviolet (UV) rays. However, abnormal and excessive production of melanin causes hyperpigmentation disorders, such as freckles, age spots, and discoloration. Natural cosmeceuticals are a new trend for treating or preventing hyperpigmentation due to fewer side effects and biocompatibility. In this context, the current study focused on Cnidium japonicum, a halophyte with several uses in folk medicine, to evaluate its potential as a skin-whitening agent. The effect of C. japonicum extract (CJE) on melanin production was analyzed in melanogenesis-stimulated B16F10 melanoma cells. The results showed that CJE successfully inhibited the oxidation of tyrosine and L-DOPA by tyrosinase and subsequently decreased the production of the key enzymes responsible for melanin production: tyrosinase, tyrosinase-related protein-1, and protein-2. This effect was confirmed by decreased intracellular and extracellular melanin levels in B16F10 melanoma cells after CJE treatment. Further experiments to elucidate the action mechanism revealed that CJE treatment suppressed melanin production by inhibiting the activation of glycogen synthase kinase 3 β (GSKβ)/β-catenin and protein kinase A (PKA)/cAMP-response element binding protein (CREB) pathways, which are the upstream activators of melanogenesis. In conclusion, the present study suggests that C. japonicum is a potential natural source of bioactive substances for the development of novel cosmeceuticals that can act against hyperpigmentation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.4 s.48
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• pp.485-489
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• 2004

Melanin pigmentation in human skin is a major defensive mechanism against ultraviolet light of the sun. Tyrosinase plays a key role in the biosynthesis of melanin. This is why many researches have been focused on regulations in controlling the epidermal melanization. We found that extract of Canavalia lineata inhibits mushroom tyrosinase activity, dopa oxidase activity, and melanin synthesis in B16F10 melanoma cells. To elucidate mRNA level reverse transcription polymerase chain reaction (RT-PCR) technique was used. It was revealed that A subfraction of $CHCI_3$ extract of Canavalia lineara reduced the tyrosinase mRNA expression of B16F10 melanoma cells by reverse transcription polymerase chain reaction (RT-PCR) technique.

• Neonatal Medicine
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• v.17 no.1
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• pp.147-151
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• 2010

Giant congenital melanocytic nevi are very rare, with an estimated incidence of 1 in 20,000 live births. They have a high risk of malignant melanoma transformation and neurological deficits such as neurocutaneous melanocytosis and epilepsy. Early evaluation, surgical intervention and careful long term follow up are recommended to monitor for malignant transformation. We report one case of giant congenital melanocytic nevi diagnosed at birth with the related literatures.