• 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.662-670
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• 2005

Recently many efforts were focused to understand the mechanical insights of melanogenesis to develop the agents for hyper-pigmentation and hypo-pigmentation. In the melanin bio-synthetic pathway, tyrosinase is the rate limiting enzyme, and ${\alpha}$-melanocyte stimulating hormone(MSH) stimulates melanogenesis and enhances the melanin synthesis and the tyrosinase activity. The author has analyzed the effects of Biota Orientalis Folium on the basal melanogenic activities of B16 mouse melanoma cells, and on the ${\alpha}$-MSH or tyrosinase-induced melanogenesis. Biota Orientalis Folium alone markedly suppressed melanin content and tyrosinase activity in a dose-dependent manner. The decrease of cell propagation was observed in B16 cells treated with 200${\mu}$g/ml dose of Biota Orientalis Folium, indicating that Biota Orientalis Folium-induced depigmenting effect was caused by inhibition of melanin synthesis, not due to destruction of B16 cells. Pretreatment of the cells with Biota Orientalis Folium also suppressed the increase of ${\alpha}$-MSH (10 nM) induced melanin content and tyrosinase activity. Biota Orientalis Folium inhibited the revelation of ${\alpha}$-MSH induced tyrosinase protein and tyrosinase related protein and mRNA of tyrosinase in B16 melanoma cell. These results suggest that Biota Orientalis Folium inhibits melanogenesis and abrogates ${\alpha}$-MSH and tyrosinase-induced melanogenesis in B16 melanoma cells.

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.76-81
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• 2012

The objective of the present study was to evaluate the skin depigmentation effect of the extracts of three herbs, Carthamus tinctorius seed, Cyperus rotundus and Schizonepeta tenuifolia. Their effects on tyrosinase and melanin synthesis inhibitory action were assessed. We found that the C. tinctorius seed ethanol extracts reduced the tyrosinase activity and melanin formation of B16F10 melanoma cells. The C. tinctorius seed suppressed the expression in microphthalmia associated transcription factor (MITF), tyrosinase, tyrosinase related protein 1 (TRP-1), and tyrosinase related protein 2 (TRP-2) in B16F10 melanoma cells. These results show that C. tinctorius seed inhibited melanogenesis on the B16F10 melanoma cell. The underlying mechanism of C. tinctorius seed whitening activity may be the inhibition of tyrisinase, MITF, tyrosinase, TRP-1, and TRP-2 expression. The results suggested that C. tinctorius seed has considerable potential as a natural functional ingredient with a depigmentation effect.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.434-436
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• 2007

In the previous study, we reported the inhibitory effects of Rodgersia podophylla root extract on tyrosinase activity and melanin production in melan-a cells. However, mechanism of the inhibitory activity and in vivo assay were not yet examined. This study performed the examination of the effects of Rodgersia podophylla root extract on protein expression and in vivo depigmenting activity using melan-a cells and brown guinea pigs. As the results of western immunoblotting analysis, treatment of Rodgersia podophylla root extract reduced tyrosinase expression rates in 10 and 100 ppm concentrations, dose dependently. Moreover, Rodgersia podophylla root extract exhibited depigmenting activity on UV-B induced hyperpigmentation in brown guinea pig skin. These results suggested that Rodgersia podophylla root extract could act as whitening agent for the skin via not only direct tyrosinase activity inhibition but also reducing of tyrosinase expression.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3085-3088
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• 2014

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.248.2-248.2
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• 2002

This study reports depigmenting potency of 1,3-selenazol-4-one derivatives. which would be based upon the finding of direct inhibition to mushroom tyrosinase. 1,3-Selenazol-4-one derivatives exhibited inhibitory effect on dopa oxidase activity of mushroom tyrosinase. In this study. inhibitory effects of six kinds of 1,3-selenazol-4-one derivatives (3a, 3c, 3d, 3e, 3g and 3i) on mushroom tyrosinase were investigated. (omitted)

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.4
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• pp.287-301
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• 2008

In order to develop a new depigmenting agent, extracts were obtained from 60 native plants and their antimelanogenic activities were screened by evaluating the inhibitory effect on tyrosinase which is a major enzyme responsibles for the melanin synthesis. The extracts of Trichosanthes kirilowii fruits, Phyllostachys bambusoides inner films (BIF), Clerodendrum trichotomum leaves, and Acer okamotoanum leaves showed relatively high inhibitory effect on tyrosinase and their $IC_{50}$ values were $50{\sim}100{\mu}g/mL$. The extract of BIF inhibited melanin synthesis of B16F10 melanoma cells by 52%, which was the highest among those of various extracts. Furthermore, the effect of BIF extract is 10% higher than that of arbutin (42%), a popular depigmenting agent in Korea. Ten compounds having antimelanogenic activity were isolated from the BIF extract by solvent extraction and chromatography. These compounds were identified as phenolic derivatives: SM701, SM702, SM703, and BPR211 were hydroquinone derivatives; SM707 a gallic acid derivative; SM704, SM705, SM706, SM708 and SM709 ferulic acid derivatives. The free radical scavenging activities of these compounds were measured and compared to those of hydroquinone and vitamin C. The $SC_{50}$ values scavenging 50% DPPH of SM702 and SM709 were $60{\sim}70{\mu}M$ similar to that of hydroquinone and those of SM701 and SM708 were $30{\sim}40{\mu}M$ slightly lower than that of vitamin C. These results suggest the presence of components having high antioxidant activity in the BIF extract. The SM709, identified as 1,2-O-diferulylglycerol, inhibited the activities of tyrosine hydroxylase and dopa oxidase by 18 and 60%, respectively. The SM709 also inhibited the melanin synthesis of B16F10 melanoma cells by 62% and this was the highest antimelanogenic activity among those obtained from the various purified compounds. Therefore, antimelanogenic activity of the BIF extract was concluded to be due to both inhibition of DOPA oxidase and antioxidant activity.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1444-1448
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• 2008

Down-regulation of melanin synthesis is required for recovery of pigmentary disorders and it is well known that ${\alpha}$-MSH induced melanin synthesis and dendrite outgrowth on melanocytes. This study was conducted to evaluate the depigmenting properties of ethanol extract from a Lavandula vera. The ethanol extract from Lavandula vera inhibited melanin contents and tyrosinase activity in a dose-dependent manner, compared with untreated group. Treatment of the ethanol extract of Lavandula vera effectively suppressed the ${\alpha}$-MSH-stimulated melanin formation, tyrosinase activity and dendrite outgrowth. Moreover, the ${\alpha}$-MSH-induced mRNA expression of tyrosinase was significantly attenuated by Lavandula vera treatment. These results suggest that Lavandula vera exerts its depigmenting effects through the suppression of tyrosinase and cytoplasmic dendricity. And it may be a potent depigmetation agent in hyperpigmentation condition.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1243-1249
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• 2007

The aim of this study was to investigate the effect of ethanol extract of Fagopyrum esculentum on the melanogenesis. To determine whether ethanol extract of Fagopyrum esculentum suppress melanin synthesis in cellular level, B16F10 melanoma cells were cultured in the presence of different concentrations of Fagopyrum esculentum ethanol extract. In the present study, we examined the effects of Fagopyrum esculentum ethanol extract on cell proliferation, melanin contents, tyrosinase activity, expression of melanogenic enzyme proteins including tyrosinase, tyrosinase-related protein 1 (TRP-1) and tyrosinase-related protein 2 (TRP-2). Cell proliferation was slightly increased by treatment with ethanol extract of Fagopyrum esculentum $(25-200 {\mu}g/m{\ell}).$ The ethanol extract of Fagopyrum esculentum effectively suppressed melanin contents at a dose of $100 {\mu}g/m{\ell}).$ It was observed that the color of cell pellets was totally whitened compared with the control. The ethanol extract of Fagopyrum esculentum inhibited tyrosinase activity, regulate melanin biosynthesis as the key enzyme in melanogenesis. Using western blot analysis, the ethanol extract of Fagopyrum esculentum dose-dependently decreased tyrosinase and TRP-1 protein levels, and tyrosinase and TRP-1 were detected in similar manner. ${\alpha}-MSH$ leads to a stimulation of melanin synthesis through increase of tyrosinase activity, melanin contents and cytoplasmic dendricity. In this study, ethanol extract of Fagopyrum esculentum down-regulated the ${\alpha}-MSH$-induced tyrosinase activity, melanin contents and cytoplasmic dendricity. Regarding protein levels of the melanogenic enzymes, the amounts of tyrosinase and TRP-1 was increased after incubation with a-MSH. The treatment of ethanol extract of Fagopyrum esculentum decreased the ${\alpha}-MSH$-induced expression levels of tyrosinase and TRP-1. These results suggest that the ethanol extract of Fagopyrum esculentum exerts its depigmenting effects through the suppression of tyrosinase, TRP-1 and cytoplasmic dendricity. And it may be a potent depigmetation agent in hyperpigmentation condition.

• Korean Journal of Medicinal Crop Science
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• v.14 no.3
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• pp.148-152
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• 2006

Comparison of four phenolic compounds among three different parts of Panax ginseng C.A. Meyer was performed in this study. Contents of esculetin, p-coumaric acd, quercetin, maltol in the ethyl acetate fraction were determinated by HPLC analysis. The main root has a highest concentration of p-coumaric acid and the leave has a highest concentration of quercetin and esculetin. This ethyl acetate fraction of the leaves exhibited higher depigmenting activity and lower cell toxicity than the other parts of ginseng. In addition, it showed that quercetin and esculetin among phenolic compounds highly inhibited melanin biosynthesis in ginseng. It implies that leaves of ginseng may be used as skin whitening herb. Quercetin and esculetin proved to be active compounds in the leaves of ginseng.