• Journal of Photoscience
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• v.9 no.2
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• pp.205-208
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• 2002

Nitric oxide (NO) is a newly described transmitter involved with cell to cell communication that is generated in biologic tissues by specific types of nitric oxide synthase (NOS), which metabolize L-arginine and molecular oxygen to citrulline and nitric oxide. In the skin. NO has been reported to play an important role in such diseases as psoriasis, atopic dermatitis, and contact dermatitis, as well as act as an important modulator in UVB-induced erythema. Ultraviolet B irradiation to the skin evokes an increase in NO production in the epidermis through two pathways; induction of inducible NOS, mediated by inflammatory cytokines, and elevation of constitutive neuronal NOS activity. In a cell culture system, it has been demonstrated that NO functions as a melanogen after being produced in keratinocytes in response to UVB-irradiation. NO-stimulated melanogenesis in melanocytes is mediated by the cGMP/PKG pathway. In this study, up-regulation of tyrosinase gene expression by NO-stimulation and the involvement of NO in UVB-induced pigmentation were examined. In NO-induced melanogenesis, protein synthesis and tyrosinase activity increased along with an up-regulation of tyrosinase gene expression. In an animal model, UVB-induced pigmentation in skin was suppressed by sequential daily treatments with a specific inhibitor of NOS. Thus, NO plays an important role in UVB-induced pigmentation, where its function as a melanogen is considered to be one of the mechanisms. Together with its role in the development of erythema, NO contributes to the total protective response of skin against UVB-irradiation.

• 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.

• Natural Product Sciences
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• v.19 no.3
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• pp.206-214
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• 2013

The crocetin derivatives, crocin (1), gentiobiosyl glucosyl crocetin (3), and mono-gentiobiosyl crocetin (4) were isolated from the fruit of Gardenia jasminoides (Gj) and crocetin (2) from the processed fruit of Gj (PGj) by column chromatography. Their structures were determined on the basis of spectroscopic methods including IR, MS, and NMR (1D and 2D). These compounds were evaluated for their inhibition activity on melanin production in ${\alpha}$-MSH (melanocyte stimulating hormone) activated B16F10 cells. Compounds 1 - 4 reduced melanin content in a dose-dependent manner at concentrations of 20 - 60 uM. They also suppressed tyrosinase protein and m-RNA expressions dose dependently, assayed by western blot analysis, and RT-PCR experiment in B16F10 murine melanoma cells.

• Mycobiology
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• v.47 no.1
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• pp.112-119
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• 2019

Compounds from Lingzhi has been demonstrated the ability for inhibiting tyrosinase (a key enzyme in melanogenesis) activity. In this study, we investigated the anti-melanogenic activity from the submerged mycelial culture of Ganoderma weberianum and elucidated the skin lightening mechanism by B16-F10 murine melanoma cells. From the cellular context, several fractionated mycelium samples exhibited anti-melanogenic activity by reducing more than 40% extracellular melanin content of B16-F10 melanoma cells. In particular, the fractionated chloroform extract (CF-F3) inhibited both secreted and intracellular melanin with the lowest dosage (25 ppm). Further analysis demonstrated that CF-F3 inhibited cellular tyrosinase activity without altering its protein expression. Taken together, our study has demonstrated that the chemical extracts from submerged mycelial culture of G. weberianum have the potential to serve as an alternative anti-melanogenic agent.

• Journal of Life Science
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• v.33 no.2
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• pp.169-175
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• 2023

As a protective defensive mechanism against ultraviolet (UV) light exposure in skin tissue, melanocytes produce the pigment melanin. Tyrosinase plays a key role in melanin production in melanocytes. However, the overproduction of melanin can lead to lesions, such as freckles and dark spots. Thus, it is clinically important to find a modulating molecule to control melanogenesis by regulating tyrosinase expression and/or activity. It is known that catechin, a plant flavonoid, can reduce melano- genesis through the downregulation of tyrosinase expression. Here, we tested whether catechin derivatives isolated from the stem bark of Ulmus parvifolia have an effect on melanin production by regulating tyrosinase in mouse melanoma cells and in vitro mushroom tyrosinase. The catechin derivatives used in this study included C5A, C7A, C7G, and C7X. Treatments using these catechin derivatives reduced melanin production in mouse melanoma B16F10 cells in which melanogenesis was stimulated by α-MSH. Notably, the anti-melanogenic effects of catechin derivatives were similar to those of kojic acid, a well-known anti-melanogenic molecule. Both C5A and C7A directly inhibited the activity of tyrosinase isolated from mushrooms in vitro. Furthermore, our in silico computational simulation showed that these two compounds were expected to bind to the active site of tyrosinase, which is similar to kojic acid. In addition, all four catechin derivatives reduced tyrosinase protein expression. In summary, our results showed that catechin derivatives can reduce melanogenesis by regulating tyrosinase activity or expression. Thus, this study suggests that catechin derivatives isolated from U. parvifolia can be novel modulators of melanin production.

• Korean Journal of Pharmacognosy
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• v.46 no.4
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• pp.315-320
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• 2015

This study was carried out to investigate the effect of ethanolic extract Salicornia herbacea (SHEE) on melanogenesis and mechanism. The SHEE on ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH) induces melanogenesis in B16F10 melanoma cells. The effect of SHEE remarkably decreased protein expression of tyrosinase and tyrosinase relate protein (TRP)-2 increased extracellular signal related kinase (ERK) on ${\alpha}$-MSH 100 nM induced melanogenesis on B16F10 melanoma cells at dose-dependent manner. It has been reported that the activation of ERK reduce melanin synthesis by down-regulating micro-phthalmia-associated transcription fator (MITF). These results sugggest that possibility of extracted korean medicinal herbs as a functional ingredient for whitening cosmetic formula.

• Korean Journal of Plant Resources
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• v.30 no.2
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• pp.144-151
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• 2017

This study examined the anti-inflammatory and whitening effects of Amaranth (Amaranthus spp L.) seed extract. Amaranthus spp L. seeds were extracted using 70% ethanol and then fractionated sequentially with n-hexane, dichloromethan, ethyl acetate and butanol. For the study of anti-inflammatory activity in RAW 264.7 cells, EtOAc fraction of Amaranthus spp L. seeds significantly inhibited nitrogen oxide production as well as the protein level of iNOS. Furthermore, EtOAc fraction of Amaranthus spp L. seeds inhibited expression of $TNF-{\alpha}$, PGE2 and the protein level of COX-2 in a dose-dependent manner. Inaddition, the tyrosinase inhibitory activities of the Amaranthus spp L. seed 70% ethanol extract and subfractions were also measured to see if these extracts can be used as an ingredient for whitening cosmetics. Tyrosinase is an oxidase that is a rate-limiting enzyme for controlling the production of melanin. Therefore, tyrosinase inhibitors have become increasingly important in cosmetics and medical products with regards to hyperpigmentation. EtOAc fraction of Amaranthus spp L. seeds showed mushroom tyrosinase inhibitory activity in a dose-dependent manner. This activity was more potent than that of a positive control cynandione A. These results suggest that Amaranthus spp L. seeds may be a valuable natural ingredient for the food and cosmetics industries.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.3
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• pp.649-653
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• 2008

The aqueous extract from Asiasari radix (AEAR) was used to investigate the effect of ${\alpha}$-melanocyte stimulating hormone induced melanogenesis in B16F10 mouse melnoma cells. The treatment with AEAR at the 1.0 and 2.0 mg/ml level significantly inhibited the biosynthesis of melanin without changes of cell growth and morphology compared with untreated control. The AEAR-treated cells at the 2.0 mg/ml level were more efficient than commercial arbutin at 0.1 mg/ml. The tyrosinase activity also significantly decreased in AEAR-treated cells at the 1.0 and 2.0 mg/ml level. The Western analyses confirmed the slightly decreased expression of tyrosinase by AEAR treatment. These results indicate that AEAR may contribute to the inhibition of melanin biosynthesis through regulating tyrosinase activity and expression and serve as a new candidate in the design of new skin-whitening or therapeutic agents.

• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.72-76
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• 2016

We investigated the application of functional materials by examining a variety of physiological activities of Geranium krameri extract obtained from the National Institute of Horticultural and Herbal Science. Geranium krameri extract had a low cytotoxicity against murine melanoma B16F10 cells. At concentrations with little or no cytotoxicity, Geranium krameri extract showed high DPPH radical scavenging activity ($IC_{50}$, $8.72{\mu}g/mL$) and anti-microbial activities against Bacillus subtilis, Escherichia coli, and Candida albicans. Additionally, Geranium krameri extract inhibited tyrosinase activity ($IC_{50}$, $456.86{\mu}g/mL$) and decreased melanin content ($IC_{50}$, $50.35{\mu}g/mL$). The treatment of B16F10 cells with Geranium krameri extract suppressed the protein expression of tyrosinase in a dose-dependent manner. These findings suggest that Geranium krameri extract inhibits melanin synthesis in murine melanoma B16F10 cells by suppressing intracellular tyrosinase expression, as well as directly inhibits tyrosinase activity simultaneously.

• Journal of Life Science
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• v.23 no.12
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• pp.1428-1435
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• 2013

The aim of this study is to investigate the melanogenic effect of Oenanthe javanica ethanolic extracts (OJE) containing quercetin and kaempferol in melanoma cells (B16F1). In order to determine whether OJE inhibits melanin synthesis at the cellular level, the melanoma cells were cultured in the presence of different concentrations of OJE. In the present study, the antioxidant effects of OJE on DPPH radical scavenging, power reduction, lipid peroxidation, and DNA oxidation were evaluated in a cell free system. Furthermore, the effect of OJE on the production of melanin was determined by dopaquinone (DOPA) assay and tyrosinase activity. In addition, the protein expression of tyrosinase, as well as antioxidant enzymes such as superoxide dismutase (SOD)-1, SOD-2 and glutathione reductase (GSH), were examined using Western blot analysis. In this study, it was observed that OJE exhibited an inhibitory effect on lipid peroxidation and blocked the DNA oxidation induced by the hydroxyl radical produced by Fenton's reagent. OJE increased melanin synthesis above 50 ${\mu}g/ml$ and tyrosinase activity was detected above 50 ${\mu}g/ml$. In Western blot analysis, OJE increased the expression levels of tyrosinase, SOD-1, SOD-2, and GSH in a dose-dependent manner. These findings indicate that OJE with antioxidant activity can regulate the tyrosinase activity and melanin production in melanocyte, suggesting that it could promote the development of black hair as well as protect skin from oxidative stress.