• KSBB Journal
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• v.19 no.2
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• pp.118-124
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• 2004

Melanocytes synthesize melanin within discrete organelle termed melanosomes which are transferred to the surrounding keratinocytes and can be produced in varying sizes, numbers and densities. Skin whitening products have become increasingly popular in the past few years. The most successful natural skin whitening agents are: Arbutin, Vitamin C, Kojic acid, Mulberry, which are all tyrosinase inhibitors. In this work, melanoston, a melanogenesis inhibitor isolated from yeast was studied to understand its mechanism of melanogenesis inhibition. It was found that melanoston was not a tyrosinase inhibitor, while when melanoston was applied to the B16 melanoma cell culture media, the intracellular tyrosinase activity was decreased by more than 30％, When B16 melanoma was stimulated with ${\alpha}$-MSH, cell morphololgy was dramatically changed to have lots of dendrites on the cell membrane surface. On the other hand, B16 was treated with ${\alpha}$-MSH and melanoston, simultaneously, the change of cell morphology was not so great. This inhibition effect of melanoston was found to be related to the inhibition of intracellular activation and transportation of tyrosinase, which was observed by immunostaining of B16 melanoma using anti-tyrosinase antibody. From these results, melanoston was regarded as an inhibitor to the differentiation of melanoma cells.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.25-33
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• 2005

Melanocytes synthesize melanin within discrete organelle termed melanosomes which are transferred to the surrounding keratinocytes and can be produced in varying sizes, numbers and densities. Skin whitening products have become increasingly popular in the past few years. The most successful natural skin whitening agents are: arbutin, vitamin C, kojic acid, and mulberry, which are all tyrosinase inhibitors. In this work, melanoston, a melanogenesis inhibitor isolated from yeast was studied to understand its mechanism of melanogenesis inhibition. It was found that melanoston was not a tyrosinase inhibitor, while when melanoston was applied to the B16 melanoma cell culture media, the intracellular tyrosinase activity was decreased by more than $30\%$. When B16 melanoma was stimulated with $\alpha$-MSH, cell morphololgy was dramatically changed to have lots of dendrites on the cell membrane surface. On the other hand, B16 was treated with $\alpha$-MSH and melanoston, simultaneously, the change of cell morphologv was not so great. This inhibitory effect of melanoston was found to be related to the inhibition of intracellar activation and transportation of tyrosinase, which was observed by irmmunostaining of B16 melanoma using anti-tyrosinase antibody. From these results, melanoston was regarded as an inhibitor to the differentiation of melanoma cells.

• 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.4
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• pp.226-232
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• 2017

In this study, ethanol extract of Epimedium koreanum Nakai(EEKN) enhanced melanogenesis by inducing expression of tyrosinase and tyrosinase-related protein-1 (TRP-1). But EEKN did not increase the protein expression of tyrosinase-related protein 2 (TRP-2). Moreover, EEKN enhanced tyrosinase activity and melanin contents of B16F10 cells. EEKN raised the expression of CREB phosphorylation and microphthalmia-associated transcription factor (MITF) as a key transcription factor for tyrosinase expression regulating melanogenesis. And PKC inhibitor H89 supressed that EEKN induced tyrosinase activity, melanin contents, and expression of tyrosinase, TRP-1. These results suggest that melanogenesis-promoting effect of EEKN was correlated with regulation of tyrosinase and TRP-1 protein through cAMP/PKC pathway.

• KSBB Journal
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• v.9 no.5
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• pp.525-531
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• 1994

Tyrosinase has two types of enzymatic activities, cresolase catalyzing the hydroxylation of monophenol and catecholase catalyzing the oxidation of o-phenol. Gradual inactivation of the enzyme during the reaction is a barrier to be overcome for the commercial application of the enzyme. Tyrosinase was stabilized by modifying the lysine residue of the enzyme using glutaraldehyde. In addition to that, tyrosinase was also stabilized by adapting the continuous reactor system. In packed bed reactor quinone could be easily removed, so the stability of tyrosinase increased. Borate buffer retarded the reaction rate of catechol to quinone and consequently decreased the tyroslnase inactivation. Tyrosinase immobilizer on controlled pore glass showed significantly enhanced stability in a packed-bed reactor.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.1
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• pp.149-157
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• 2010

목적 : 월견초는 다량의 불포화 지방산인 리놀렌산과 감마 리놀렌산을 함유하고 있으며, 천식성 기침이나 아토피피부염에 효능이 있는 것으로 알려져 있다. 본 연구는 월견초의 전초와 종자 추출물의 피부 멜라닌 합성에 대한 억제 효과를 조사하였다. 방법 : B16F10 멜라닌세포주를 이용하여 멜라닌, tyrosinase 활성 및 세포생존율을 측정하였다. 또한 멜라닌 합성- 관련효소인 tyrosinase, TRP-1, TRP-2의 단백질발현과 $\alpha$-MSH를 처리하여 색소침착을 유도 한 뒤 단백질 발현을 조사하였다. 결과 : 월견자는 B16F10 세포의 멜라닌 합성을 $5\;{\mu}g/ml$와 $10\;{\mu}g/ml$ 농도에서 각각 대조군의 81.3%, 68.3%로 억제하였고 tyrosinase의 활성도 이와 유사하게 억제하였다. 멜라닌 합성-관련효소들의 단백질발현을 관찰한 결과 월견초와 월견자는 tyrosinase 발현을 억제하였으며 TRP-1과 TRP-2의 발현에는 영향을 주지 않았다. 특히 $\alpha$-MSH에 의한 과색소 유도 시 tyrosinase 발현이 현저하게 감소되었으며, 월견자의 멜라닌 합성 억제 효과가 월견초 보다 높게 나타났다. 결론 : 이상의 연구 결과 월견자는 멜라닌세포의 tyrosinase 단백질 발현과 tyrosinase 활성을 억제하여 멜라닌 생성을 감소시키는 것으로 사료된다.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.518-523
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• 1997

To isolate biologically active compounds which exhibit tyrosinase inhibition activity and ultimately express skin whitening effect, 14 oriental herbal drugs were screened in ter ms of tyrosinase inhibition. For this purpose, in vitro enzyme assay system for tyrosinase, so called Pomerantz method with some modifications has been established. Crude methanolic extracts from 14 herbal drugs were made and examined for their inhibitory activity against tyrosinase. Those extracts from Cnidii Rhizoma, Arecae Semen, Caryophylli Flos, and Ephedrae Herba showed strong inhibitory activities on mushroom tyrosinase. Therefore, crude methanolic extracts from those 4 herbal drugs were further fractionated using ether, butanol and water. respectively. The ether and n-butanol extracts from Arecae Semen and the n-butanol and water extracts from Caryophylli Flos, respectively, showed relatively strong tyrosinase inhibitory activity compared to arbutin.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.137-141
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• 2019

At concentrations with little or no cytotoxicity, C. arvensis extract indicates the ability of high DPPH radical scavenging, inhibited tyrosinase activity, and decreased melanin content. The treatment of B16F10 cells with C. arvensis extract suppressed the protein expression of tyrosinase a dose-dependent manner. These results suggest that C. arvensis extract inhibits melanin synthesis by inhibiting tyrosinase expression and tyrosinase activity. In addition, C. arvensis extract showed antimicrobial activities against bacteria and yeast. These results indicate that C. arvensis extract may serve as nutraceutical and cosmeceutical agents.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.167-173
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• 2021

Reactive oxygen species (ROS) disrupt the cellular redox balance, exert cytotoxic effects, and consequently promote the development of various diseases in humans. Previous studies have reported that antioxidants counteract the adverse effects of ROS. Several studies examine the whitening effects of various agents based on their ability to inhibit tyrosinase activity. Tyrosinase is a critical enzyme involved in the synthesis of melanin, which protects the skin against radiation. Various agents exhibiting antioxidant and tyrosinase inhibitory activities have been synthesized. However, these synthetic drugs are associated with toxicity, decreased safety, and poor skin penetration in vivo, which has limited the clinical application of synthetic drugs. This study examined the antioxidant and tyrosinase inhibitory activities of some microalgae. The methanol, dichloromethane, and ethyl acetate extracts of four microalgal species (Tetraselmis tetrathele, Dunaliella tertiolecta, Platymonas sp., and Chaetoceros simplex) were prepared. The physiological and whitening effects of microalgal extracts were investigated by measuring the antioxidant and tyrosinase inhibitory activities. The ethyl acetate extract of D. tertiolecta exhibited the highest antioxidant and tyrosinase inhibitory activities. Future studies must focus on examining the whitening effects of microalgae on cell lines to facilitate the development of microalga-based therapeutics for skin diseases, functional health foods, and whitening agents. Thus, microalgae have potential applications in the pharmaceutical, food, and cosmetic industries.

• ALGAE
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• v.30 no.2
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• pp.163-170
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• 2015

Tyrosinase inhibitors are an important component of cosmetic products. Our previous studies have proposed that eckol isolated from the brown alga Ecklonia cava, can be explored as a tyrosinase inhibitor. However, cellular activities and mechanism of action of eckol remain unknown. Therefore, the current study analyzed the eckol binding modes using the crystal structure of Bacillus megaterium tyrosinase. The effects of eckol on melanin synthesis induced by ${\alpha}$-melanocyte stimulating hormone in B16F10 melanoma cells were also investigated. We predicted the 3D structure of tyrosinase and used a docking algorithm to simulate binding between tyrosinase and eckol. These molecular modeling studies were successful (calculated binding energy value, $-115.84kcal\;mol^{-1}$) and indicated that eckol interacts with Asn205, His208, and Arg209. Furthermore, eckol markedly inhibited tyrosinase activity and melanin synthesis in B16F10 melanoma cells. We also found that eckol decreased the expression of tyrosinase, tyrosinase-related protein (TRP) 1, and TRP2. These results indicate that eckol is a potent inhibitor of melanogenesis, and this finding may be useful for the development of novel pharmaceutical and cosmetic agents.