• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.179-186
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• 2014

This study was performed to DPPH radical scavenging activity, ABTS radical scavenging activity, tyrosinase inhibition activity and intracellular melanin synthesis inhibition to verify the whitening effect of Fagopyrum tataricum (bitter buckwheat) extract as contrasted with Fagopyrum esculentum (sweet buckwheat) extract. F. tataricum extract in consequence showed higher antioxidant activities, tyrosinase inhibition activity and melanin synthesis inhibition compared with F. esculentum extract. We investigated skin bright value during 8 weeks after induction of pigmentation in human skin from UV irradiation. In result, we obtained statistically a significant skin whitening effect from visual and mechanical evaluation. Accordingly, F. tataricum extract is expected to be high availability as functional cosmetic material for skin whitening.

• 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.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.431-437
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• 2014

Synthetic compounds that are used in the clinic to regulate skin hyperpigmentation, such as arbutin, hydroquinone, and kojic acid, are only moderately effective. But, their use is limited by side effects. As part of an effort to overcome the limitations, we developed resveratrol-enriched rice (RR) using genetic engineering technique. Each of resveratrol and rice has been reported to produce anti-melanogenic effects. Therefore, we hypothesized that RR would show more anti-melanogenic effects than those of resveratrol or rice alone. Anti-melanogenic effect of RR was done by using melan-a mouse melanocytes. The depigmenting efficacy was then observed following topical application of the RR to UVB-stimulated hyperpigmented dorsal skin of guinea pigs. Treatment with RR extract resulted a $21.4{\pm}0.7%$ decrease in tyrosinase expression at melan-a cells. Colorimetric analysis showed a significantly lower depigmenting value by day 9 following treatment with RR in UVB-irradiated guinea pigs the dorsal skin (p<0.01), indicating that RR produced a depigmentation effect. By staining with Fontana-Masson stain, we found that the RR-treated group had more effect histopathologically in epidermal melanin production than resveratrol or rice alone-treated group. RR was associated with reduction in the levels of microphthalmia-associated transcription factor (MITF), and downregulation of tyrosinase and tyrosinase-related protein (TRP-2) expression, leading to inhibit epidermal melanin production by western blot analysis. This study suggests that the resveratrol-enriched rice may be a promising candidate in regulating skin pigmentation with UVB exposure.

• Natural Product Sciences
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• v.15 no.1
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• pp.27-31
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• 2009

The present study was performed to investigate the binding affinity of the ethanol extract from the leaves of Morus alba (EMA) and some EMA related plant materials (EMA-D, EMA-DM) for melanin-concentrating hormone-1 receptor (MCH-1) and also to examine the antagonistic effect of them for the recombinant MCH-1 receptor expressed in CHO cells. EMA, dichloromethane fraction (EMA-D) and EMA-DM exhibited high affinity for mammalian MCH receptor in receptor binding assays ($IC_{50}$ value: 2.3, 1.6 and $1.0{\mu}g/ml$, respectively). Other plant materials (MMA-D, MMA-DM) obtained from methanol extracts from the leaves of Morus alba (MMA) also exhibited high affinity for mammalian MCH receptor, even though the $IC_{50}$ values of them were lower than those of EMA-D and EMA-DM. In Chinese hamster ovary (CHO) cells expressing human MCH-1, EMA-DM and EMA-D significantly inhibited MCH-induced intracellular $Ca^{2+}$ increase ($IC_{50}$ values: 16.5 and $22.7{\mu}g/ml$, respectively). These results clearly indicate that the ethanol extract from the leaves of Morus alba (EMA) and some EMA related plant materials (EMA-D, EMA-DM) are novel selective MCH-1 receptor antagonist, respectively.

• Preventive Nutrition and Food Science
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• v.15 no.3
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• pp.213-220
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• 2010

To examine the potential of Terminalia chebula as a whitening agent, we measured antioxidant activity using DPPH$\cdot$, ABTS${\cdot}^+$ assays and ferric-reducing antioxidant power (FRAP) assays, and depigmenting activity using B16F10 melanoma cells. The intracellular reactive oxygen species (ROS) level was monitored by $H_2DCFDA$ fluorescence labeling, and melanin contents in B16F10 melanoma cells by 960 $J/m^2$ dose of UVA-induced oxidative stress. The radical-scavenging activities of T. chebula extract (TCE) were measured in terms of $EC_{50}$ values using DPPH$\cdot$, ABTS${\cdot}^+$ assays and FRAP value were 280.0 ${\mu}g/mL$, 42.2 ${\mu}g/mL$ and 113.1 ${\mu}mol$ $FeSO_4{\cdot}7H_2O/g$, respectively. We found that ROS and melanin concentrations were reduced by TCE treatments of 25 ${\mu}g/mL$ under UVA-induced oxidative stress. Tyrosinase activity and melanin contents in $\alpha$-melanocyte stimulating hormone (MSH)-induced melanoma cells both decreased dose-dependently in the treatment groups. TCE similarly reduced melanogenesis in B16F10 melanoma cells stimulated by $\alpha$-MSH as compared to arbutin as a positive control. T. chebula may prove to be a useful therapeutic agent for hyperpigmentation and an effective component in skin whitening and.or lightening cosmetics.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.3
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• pp.273-280
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• 2015

In this study, we used the mixture made from the Rice bran 45 ㎏, Dendropanax 5 ㎏, the sugar of the 10% of the total weight, and the enzyme of the 0.1% of the total weight. After the mixture were fermented for 90 days under 20 $^{\circ}C$, we measured the cell viability and the inhibition rate of the melanin biosynthesis, the activity of tyrosinase and superoxide dismutase (SOD) in malignant melanoma, B16F10 cells, in order to survey the whitening effect and the mechanism of the effects on the sample. As a result, the samples significantly suppressed the cell viability of B16F10 in more than 500 ${{\mu}g}$/㎖ and significantly inhibited the generation of melanin induced by ${\alpha}$-MSH in more than 1,000 ${{\mu}g}$/㎖. Sample decreased the activity of tyrosinase while increased the activity of SOD in dose dependent manner. Therefore, we considered that the fermentation extract made from a Rice bran and Dendropanax will be able to produce high value-added products, if used as a commercial.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2005.10a
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• pp.56-65
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• 2005

This study was purposed to investigate the antioxidative effects, the enzyme activity of the alcohol metabolizing and melanin production of Maesil(Prune mume). The antioxidant activity of Maesil(Prunu mume) was analyzed by measuring thiobarbituric acid reactive substances(TBARS value) and electron donating ability. And we investigated the changes of alcohol dehydrogenase(ADH) and acetaldehyde dehydrogenase(ALDH) activity by measuring the maximum absorbency at 340nm in vitro and human study. The inhibitory effects of Maesil were investigated in vitro and in B-16mouse melanoma cells on melanin biosynthesis that is closely related to hyperpigmentation. The antioxidant activities for TBA values were 29.65% in ascorbicacid, 45.35% in BHT, 15.99% in extract of dehydrated maesil flesh(EDMF) and 25.00% in extract of dehydrated maesil juice(EDMJ). The electron donating abilities by DPPH were 96.69% in ascorbic acid, 77.82% in BHT, 34.25% in EDMF, and 42.99%in EDMJ. Electron donating abilities by DPPH in the presence of 0.02% EDMF and EDMJ were 53.21% and 59.19% respectively. Facilitating rates of ADH activity were 137.92, 131.58, 152.96, 218.70, 111.76, and 144.27% in maesil juice, 5, 10, and 15% GMT, and 0.5 and 1.0% aspartic acid, respectively. ALDH activity increased in the order of Maesil juice > ALDH > GMT > aspartic acid, and facilitating rate of ALDH activity in Maesil juice was the highest at 976.44%. Maesil extracts inhibited tyrosinase activity that converts dopa to dopachrome in the biosynthesis process. B-16 cells treated by Maesil extracts showed that the viability was over 80%. Maesil and maesil products in vitro and B-16 cells inhibited melanin production significantly.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.160-164
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• 2021

This study investigated various physiological activities to examine the applicability of the functional materials of Allium tuberosum root extract. The A. tuberosum root extract showed a low cytotoxicity against murine melanoma B16F10 cells. It also showed high DPPH radical scavenging activity (ID50, 6.2 ㎍/mL), inhibited tyrosinase activity (ID50, 115.4 ㎍/mL), and decreased melanin content (ID50, 31.5 ㎍/mL). Treatment of B16F10 cells with A. tuberosum root extract suppressed the protein expression of tyrosinase in a dose-dependent manner. These findings suggest that A. tuberosum root extract inhibits melanin synthesis by suppressing intracellular tyrosinase expression. Additionally, A. tuberosum root extract inhibited elastase with an ID50 value of 145.1 ㎍/mL and contained isoquercitrin. These results indicate that A. tuberosum root extract is an appropriate natural material.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2007.11a
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• pp.79-92
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• 2007

Oxidative stress have known to be a risk factor for the degenerative processes and closely related to a lot of diseases. It is well established that antioxidants are good in protection and therapeutic means against oxidative damage. There is increasing interest in natural antioxidants and many natural antioxidants have been found and utilized as the possible protection for various diseases and skin aging. We have screened natural antioxidant agents for cosmeceuticals, nutraceuticals, and drugs as therapeutic and preventive means against oxidative stress, and have developed a number of novel antioxidants from various natural sources. A novel melanin synthesis inhibitor, Melanocin A, isolated from the metabolite of a fungal strain Eupenicillium shearii F80695 inhibited mushroom tyrosinase and melanin biosynthesis of B16 melanoma cells with $IC_{50}$ value of 9.0 nM and MIC value of $0.9\;{\mu}M$, respectively. Melanocin A also exhibited potent antioxidant activity by scavenging of DPPH and superoxide anion radicals. UV was found to increase the level of hydrogen peroxides and other reactive oxygen species (ROS) in skin tissues. This increase in ROS may not only alter the structure and function of many genes and proteins directly but may also modulate their expressions through signal transduction pathways and, ultimately, lead to skin damage. We investigated the effect of Melanocin A on UV-induced premature skin aging. Firstly, the effect of Melanocin A on UV-induced matrix metalloproteinase (MMP)-9 expression in an immortalized human keratinocyte cell line, HaCaT in vitro was investigated. Acute UV irradiation induced MMP-9 expression at both the mRNA and protein levels and Melanocin A suppressed this expression in a dose-dependent manner. We then investigated UV-induced skin changes in hairless mice in vivo by Melanocin A. Chronic exposure of hairless mouse dorsal skin to UV increased skin thickness and induced wrinkle formation and the gelatinase activities of MMP-2 and MMP-9. Moreover, Melanocin A significantly suppressed UV-induced morphologic skin changes and MMP-2 and MMP-9 expression. These results show that Melanocin A can prevent the harmful effects of UV that lead to skin aging. Therefore, we suggest that Melanocin A should be viewed as a potential therapeutic agent for preventing and/or treating premature skin aging. Terrein is a bioactive fungal metabolite isolated from Penicillium species. Terrein has a relatively simple structure and can be easily synthesized. However, the biologic effects of terrein are comparatively unknown. We found for the first time that terrein potently inhibit melanin production in melanocytes and has a strong hypopigmentary effect in a spontaneously immortalized mouse melanocyte cell line, Mel-Ab. Treatment of Mel-Ab cells with terrein (10-100 mM) for 4 days significantly reduced melanin levels in a dose-dependent manner. In addition, terrein at the same concentration also reduced tyrosinase activity. We then investigated whether terrein influences the extracellular signal-regulated protein kinase (ERK) pathway and the expression of microphthalmia-associated transcription factor (MITF), which is required for tyrosinase expression. Terrein was found to induce sustained ERK activation and MITF down-regulation, and luciferase assays showed that terrein inhibits MITF promoter activity in a dose-dependent manner. To elucidate the correlation between ERK pathway activation and a decreased MITF transcriptional level, PD98059, a specific inhibitor of the ERK pathway, was applied before terrain treatment and found to abrogate the terrein-induced MITF attenuation. Terrein also reduced the tyrosinase protein level for at least 72 h. These results suggest that terrain reduces melanin synthesis by reducing tyrosinase production via ERK activation, and that this is followed by MITF down-regulation.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.414-419
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• 2010

Plants extracts are good resources to find functional compounds for human health. The following eight plants were collected and total phenolic contents were determined. Acer psedo-siebolianum showed the highest phenolic contents, 16.4 mg/g, whereas Cercidiphyllum japonica showed the lowest contents, 1.9 mg/g. The DPPH free radical scavenging capacities of the plant extracts showed high activity in following order : Acer ginnala ($21.3\;{\mu}g/mL$) > Cornus walteri ($23.9\;{\mu}g/mL$) > Distylum racemosum ($29.2\;{\mu}g/mL$) > Castanopsis cuspidata var. Thunbergii ($31.7\;{\mu}g/mL$) > Acer psedo-siebolianum ($34.6\;{\mu}g/mL$) > Thuijopsis dolabrata cv. Aurea ($53.1\;{\mu}g/mL$) > Cercidiphyllum Japonica ($115.2\;{\mu}g/mL$). Also the mushroom tyrosinase inhibitory activities of total extracts were determined at different concentration. D. racemosum extract showed highest (49.1% at 1,000 mg) in inhibitory activity than other seven extracts. The ethanol fraction $IC_{50}$ value: $118.1\;{\mu}g/mL$) from D. racemosum showed more inhibitory activity than ethyl acetate fraction ($IC_{50}$ value: $203\;{\mu}g/mL$). The ethanol fraction on showed no significant cytotoxicity in B16/F1 cells line up to $60\;{\mu}g/mL$. Over $80\;{\mu}g/mL$ of ethanol fraction showed cytotoxicity in B16/F1 cells. The melanin contents of cells were significantly attenuated by ethanol fraction in a dose-dependent manner. The $IC_{50}$ value of ethanol fraction was $75.4\;{\mu}g/mL$.