• Archives of Pharmacal Research
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• 제27권3호
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• pp.334-339
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• 2004

In this study, the effects of (-)-epigallocatechin-3-gallate (EGCG) and/or hinokitiol (${\beta}-thujaplicin$) on melanogenesis were investigated. Our results showed that both EGCG and hinokitiol significantly inhibited melanin synthesis in a concentration-dependent manner, and that their hypopigmenting effects were stronger than that of kojic acid, which is known to inhibit melanin formation in melanocytes and melanoma cells. Interestingly, EGCG did not show any additive hypopigmenting effect in combination with kojic acid, though EGCG did show a synergistic effect in combination with hinokitiol. Several reports indicate that the activation of extracellular signal-regulated kinase (ERK) induces microphthalmia-associated transcription factor (MITF) degradation. Accordingly, the effects of EGCG and hinokitiol on the ERK signaling pathway were examined. EGCG and hinokitiol induced neither ERK activation nor MITF degradation. On the other hand, both EGCG and hinokitiol reduced the protein levels of MITF and of tyrosinase, the rate limiting melanogenic enzyme, whereas kojic acid had no effect. In addition, hinokitiol strongly downregulated the activity of tyrosinase, whereas EGCG or kojic acid had only a little effect. These results show that both EGCG and hinokitiol reduce MITF production, and suggest that reduced tyrosinase activity by hinokitiol explains their synergistic effect on melanogenesis.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1241-1248
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• 2011

Three dimensional quantitative structure-activity relationships (3D-QSARs) between new thiosemicarbazone analogues (1-31) as a substrate molecule and their inhibitory activity against tyrosinase as a receptor were performed and discussed quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) methods. According to the optimized CoMSIA 2 model obtained from the above procedure, inhibitory activities were mainly dependent upon H-bond acceptor favored field (36.5%) of substrate molecules. The optimized CoMSIA 2 model, with the sensitivity of the perturbation and the prediction, produced by a progressive scrambling analysis was not dependent on chance correlation. From molecular docking studies, it is supposed that the inhibitory activation of the substrate molecules against tyrosinase (PDB code: 1WX2) would not take place via uncompetitive inhibition forming a chelate between copper atoms in the active site of tyrosinase and thiosemicarbazone moieties of the substrate molecules, but via competitive inhibition based on H-bonding.

• Molecular & Cellular Toxicology
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• 제2권2호
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• pp.81-88
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• 2006

Sphingolipid metabolites regulate many aspects of cell proliferation, differentiation, and apoptosis. In the present study, we have assessed the effects of the novel phytosphingosine derivative, N-acetylphytospingosine (NAPS), on the depigmentation of murine B16F10 melanoma cells, and have also attempted to identify the possible signaling pathway involved, in comparison with $C_{2}-ceramide$. NAPS and $C_{2}-ceramide$ both inhibited the growth of the B16F10 cells in a dose-dependent manner. Melanin content and tyrosinase activity were significantly reduced in response to treatment with NAPS and $C_{2}-ceramide$ at concentrations in a range between $1-5\;{\mu}M$. However, the levels of tyrosinase mRNA, as well as the levels of tyrosinase related protein-1 (TRP-1) and tyrosinase related protein-2 (TRP-2) genes and the level of tyrosinase protein remained unaffected by treatment with either NAPS or $C_{2}-ceramide$. We also attempted to determine the signaling pathway exploited by NAPS and $C_{2}-ceramide$. Interestingly, the phosphorylation of Akt/PKB at serine 473 by NAPS was reduced at the 5 minute mark, whereas $C_{2}-ceramide$ induced the phosphorylation of Akt/PKB at serine 473. Finally, Akt/PKB activity in the NAPS-treated cells was elevated in comparison with the untreated cells. LY294002, a specific PI3-K inhibitor which is located upstream of Akt/PKB, inhibited the phosphorylation of Akt/PKB, but induced an increase in melanin synthesis. These results suggest that the activation of Akt/PKB at serine 473 is related with the suppression of melanin production in the B16F10 mouse melanoma cells. Therefore, the mechanisms exploited by NAPS and $C_{2}-ceramide$ responsible for the depigmentation of B16F10 cells were concluded to involve the inhibition of melanosomal tyrosinase activity.

• 생명과학회지
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• 제20권11호
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• pp.1617-1624
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• 2010

$\alpha$-MSH는 세포내 cAMP를 증폭시켜 멜라닌세포의 증식과 색소 증가에 관여한다. 본 연구에서는 $\alpha$-MSH로 자극한 B16F10 세포에서 세신추출물의 hypopigmenting 효과를 조사하고 그 억제기전에 대하여 조사하였다. 세신추출물은 $\alpha$-MSH에 의해 유도된 tyrosinase 활성과 멜라닌생성을 효과적으로 억제시켰으며, 이는 tyrosinase 발현을 조절하는 전사인자인 MITF의 발현억제와 연관성이 있었다. 즉 세신추출물은 MEK/ERK와 PI3K/Akt의 활성화를 통하여 MITF를 조절함으로서 $\alpha$-MSH에 의해 유도되는 tyrosinase, TRP-1, Dct 등 멜라닌생성관련 단백질을 억제함으로서 멜라닌생성을 저해하는 것으로 사료된다.

• 동의생리병리학회지
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• 제19권1호
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• pp.196-203
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• 2005

Gunggui-tang has been used for the therapy of blood disorders in Hangbang medicine for long time. Also, Glycyrrhiza uralensis has been used for deficientblood patterns with an irregular pulse or palpitations, coughing and wheezing, and heat or cold in the lungs. Melanogenesis is a physiological process resulting in the synthesis of melanin pigments. We investigated whether the water extract of Gunggui-tang plus G. uralensis inhibited melanogenesis in B16 melanoma cells. Because the molecular events connecting the regulation in tyrosinase activity remain to be elucidated, we also aimed to determine whether Gunggui-tang gamibang(GTG) affects tyrosinase at the gene activation level in the cells. First, we showed that GTG inhibited the tyrosinase promoter activity and further, down-regulated the tyrosinase protein activity in ${\alpha}-melanocyte-stimulating$ hormone $({\alpha}-MSH)-treated$ B16 melanoma cells. GTG also resulted in a decrease of melanin content in MSH-induced melanogenesis, indicating that GTG may be a useful drug in studying the regulation of melanogenesis. The pretreatment of GTG significantly prevented phosphotransferase activity of c-Jun N-terminal kinase (JNK1) and transcriptional activation of activating protein-1 (AP-1) in MSH-treated B16 melanoma cells. These findings indicate that GTG inhibits melanogenesis of B16 melanoma cells via suppression of phosphotransferase activity of JNK1 and transcriptional activation of AP-1.

• 생명과학회지
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• 제24권5호
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• pp.485-490
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• 2014

백복령(Poria cocas)은 전통적으로 민간에서 피부미백에 효과가 있다고 보고되어 있다. 지금까지 melanin 합성에 대한 백복령의 직접적인 효과는 과학적으로 잘 연구되어 있지 않다. 따라서 멜라닌 합성에 대한 백복령 주정 추출물(PCEE)의 직접적인 효과를 밝히기 위해, 쥐의 B16F1 세포를 이용하여 DOPA synthesis assay, tyrosinase activity assay, Western blotting for melanogenic proteins [tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2]를 수행하였다. 본 연구에서 PCEE가 3,4-dihydroxyindole-2-carboxylic acid (DOPA) 합성을 차단함으로써 농도 의존적으로 melanin형성을 억제한다는 것이 밝혀졌다. 비록 tyrosinase의 활성은 영향을 받지 않았지만 TRP-1 과 TRP-2의 단백질 발현 수준은 PCEE에 의해 조절되었다. 따라서 이러한 결과는 PCEE가 미백 효능을 가지고 있어 미백 화장품 개발을 위해 이용될 수 있다는 것을 시사하고 있다.

• 대한본초학회지
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• 제30권4호
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• pp.95-100
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• 2015

Objectives : The purpose of this study was to research the whitening effects and developing by cosmetics of the extract fromDioscoreae Rhizoma, which is one of the most popular health-promoting herb in herbal medications.Methods : We performed tyrosinase inhibition assay, reverse transcription-polymerase chain reaction (RT-PCR) and western blot for whitening effects. Also we measured MTT assay for cell viability.Results : The results were obtained as follows : For whitening effect, tyrosinase inhibition rate of extract fromDioscoreae Rhizomashowed more than 42.28% at 1,000 ㎍/㎖ concentration. Cell toxicity effect on melanoma cells (B16F10) of extract fromDioscoreae Rhizomashowed 81.97% with toxicity at 50 ㎍/㎖ concentration. So we were measured at a concentrations of 5, 10 and 50 ㎍/㎖ in all experiments involving cell. In addition, whitening related mRNAs including microphthalmia associated transcription factor (MITF), tyrosinase related protein-1 (TRP-1), tyrosinase related protein-2 (TRP-2), tyrosinase were reduced byDioscoreae Rhizoma. We also foundDioscoreae Rhizomatransiently decreased protein kinase A (PKA) which is known to be upstream to the down regulation of MITF and tyrosinase. But phosphorylation of extracellular signal related kinase (pERK) were increased byDioscoreae Rhizoma. These results imply thatDioscoreae Rhizomadecrease melanogenesis via ERK activation and subsequent down regulation of MITF and tyrosinase.Conclusions : Therefore, all these findings suggested the potent usage ofDioscoreae Rhizomaas materials of functional cosmetics by confirming whitening activity related with melanin content.

• 대한한의학방제학회지
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• 제28권1호
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• pp.81-90
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• 2020

Objectives : This study was conducted to investigate the effects of major constituents of Epimedium koreanum Nakai (Icariin, epimedium A, epimedium B, and epimedium C) on melanin synthesis. Methods : We measured melanin contents, tyrosinase activity, and expression of Rab27a in B16F10 cells cultured with Epimedium koreanum Nakai ethanol extract (EKN) and their major constituents. After treatment with H89 and dibutyryl cAMP, which inhibit or promote the activation of PKA, we observed changes in melanin synthesis and tyrosinase activity stimulated by EKN. Results : Among them, EKN and icariin enhanced tyrosinase activity and melanin contents. We confirmed that EKN augmented melanin synthesis via cAMP/PKA pathway. Icariin-induced tyrosinase activity and melanin content were attenuated by PKA inhibitor H89, while melanogenic effect of icariin was further augmented by cAMP analog, dbc AMP. However, icariin did not affect the expression of small GTPase Rab27a involved in melanosome transport. Conclusions : These results suggest that icariin promotes melanogenesis through cAMP/PKA pathway but does not affect small GTPase Rab27a.

• 약학회지
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• 제56권4호
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• pp.254-259
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• 2012

To further access honeybee (Apis mellifera L.) venom (BV) as a cosmetic ingredient and potential external treatment for topical use, we investigated its ability to inhibit tyrosinase activity and melanin biosynthesis on melanogenesis in B16F1 melanoma cells. We found that BV increased the cell viability in B16F1 melanoma cell and BV (0.01~1 ${\mu}g/ml$) inhibited melanin synthesis in with 10 nM ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH) for 48 h. In addition, we used reverse transcription-polymerase chain reaction and western blotting for me melanogenesis-related genes such as tyrosinase to examine the mechanisms underlying the inhibitory effects of BV on melanogensis. BV inhibited direct tyrosinase activity, which decreased melanin synthesis in ${\alpha}$-MSH stimulated B16F1 melanoma cells. Thease findings suggest that BV induces the downregulation of melanogenesis by inhibiting tyrosinase activation.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.271.3-272
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• 2002

This study shows that sphingosine-1-phosphate (SPP) significantly inhibits melanin synthesis in a concentration-dependent manner, and that the activity of tyrosinase was also reduced in SPP-treated cells. In contrast. a specific extracellular signal-regulated protein kinase (ERK) pathway inhibitor, PD98059 increased tyrosinase activity and melanin production, and PD98059 restored the reduced tyrosinase activity and pigmentation induced by SPP. (omitted)