• YAKHAK HOEJI
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• v.55 no.6
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• pp.485-491
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• 2011

Previously, we have reported that apigenin, a natural flavonoid found in a variety of vegetables and fruits, stimulated melanogenesis through the activation of $K^+-Cl^-$-cotransport (KCC) in B16 melanoma cells. In this study we investigated the possible involvement of reactive oxygen species (ROS) in the mechanism of apigenin-induced melanogenesis in B16 cells. Apigenin elevated intracellular ROS level in a dose-dependent manner. Treatment with various inhibitors of NADPH oxidase, diphenylene iodonium (DPI), apocynin (Apo) and neopterine (NP) significantly inhibited both the generation of ROS and melanogenesis induced by apigenin. In addition these inhibitors profoundly inhibited apigenin-induced $Cl^-$-dependent $K^+$ efflux, a hallmark of KCC activity. However, the apigenin-induced ROS generation was not significantly affected by treatment with a specific KCC inhibitor R-(+)-[(2-n-butyl-6,7-dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-1H-inden-5-yl)oxy]acetic acid (DIOA). These results indicate that the ROS production may be a upstream regulator of the apigenin-induced KCC stimulation, and in turn, melanogenesis in the B16 cells. Taken together, these results suggest that the NADPH oxidase-mediated ROS production may play an important role in the apigenin-induced melanogenesis in B16 cells. These results further suggest that NADPH oxidase may be a good target for the management of hyperpigmentation disorders.

• Korean Journal of Pharmacognosy
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• v.36 no.1 s.140
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• pp.1-8
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• 2005

To develop an whitening cosmetics, we isolated the melanogenesis inhibitors from the unripe fruits of Poncirus trifoliata (Rutaceae). Isolated compounds were identified as poncirin(l), naringin(2), bis(2-methylheptyl)phthalate(3), avenalumic acid methyl ester(4) by comparison of physical and spectral data with those reported in the literature. Among the isolated compounds, bis(2-methylheptyl)phthalate showed most potent inhibitory effect on the melanogenesis in cultured B-16 mouse melanoma cell lines$(IC_{50},\;36.8\;{\mu}M)$ compared with kojic acid$(IC_{50},\;150\;{\mu}M)$.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.814-817
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• 2012

In the continued search for melanogenesis inhibitors from microbial metabolites, we found that the culture broth of Clitocybe sp. MKACC 53267 inhibited melanogenesis in B16F10 melanoma cells. The active component was purified by solvent extraction, silica gel chromatography, Sephadex LH-20 column chromatography, and finally by preparative HPLC. Its structure was determined as 5-pentyl-2-furaldehyde on the basis of the UV, NMR, and MS spectroscopic analysis. The 5-pentyl-2-furaldehyde potently inhibited melanogenesis in B16F10 cells with an $IC_{50}$ value of 8.4 ${\mu}g/ml$, without cytotoxicity.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1089-1094
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• 1996

The in vivo effect of tyrosinase inhibitors in the melanogenesis of gold fish (jet black color) was evaluated by measuring surface color and observing melanin pigment. The fish was firstly cultivated in 0.9% NaCl solution for 1 week to induce melanogenesis, and then, it was transferred to each treatment group containing tyrosinase inhibitor. The fish was grouped into control. food additive group (addition of 5 mM glutathione, 5 mM cysteine, and 1 mM benzoic acid), microbial inhibitor group (addition of culture broth of Aspergillus oryzae in shiitake and glucose medium), and plant extract group (addition of the mixed extracts of green tea, beet, red chicory, and nameko). After 6 days, the fish was anesthetized by electric shock, and color of pectoral region, lateral region, and dorsal fin was measured. Hunter's L and b values of treated group were generally higher than those of control group, indicating that the tyrosinase inhibitors could inhibit the melanogenesis of the fish. Effect of plant extract was apparent, though relatively weak, not because it did not work in vivo, but because a sufficient amount of extract could not be added to fish globes. If a large amount of extract was added, fish gradually died due to a microbial contamination. Microscopic observation of melanin in lateral scale and dorsal fin showed that in the treated groups with tyrosinase inhibitors, the number of melanophore per unit area and the size of one melanophore decreased.

• Journal of Microbiology and Biotechnology
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• v.19 no.4
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• pp.368-371
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• 2009

In the course of screening for the melanogenesis inhibitors, aspochalasin I was isolated from solid-state culture of Aspergillus sp. Fb020460. Its structure was determined by spectroscopic analysis including mass spectroscopy and NMR analysis. Aspochalasin I potently inhibited melanogenesis in Mel-Ab cells with an $IC_{50}$ value of $22.4{\mu}M$ without cytotoxicity.

• Natural Product Sciences
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• v.17 no.1
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• pp.26-32
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• 2011

Novel tyrosinase inhibitors are important for pigmentation in the skin. Following extraction of tyrosinase inhibitors from edible vegetables or fruits, we found that the Prunus persica flesh extract (PPFE) exhibited potential inhibitory activity for melanogenesis. PPFE showed tyrosinase inhibitory activity in an enzymatic assay and PPFE also significantly inhibited the melanin formation in cultured mouse melan-a cells. Moreover, real-time RT-PCR analysis revealed that the inhibition of melanin production by PPFE was closely related to marked suppression of mRNA expression of tyrosinase and tyrosinase-related protein-1 and -2 (TRP-1 and TRP-2) in melan-a cells. Further investigation found that the modulation of tyrosinase expression by PPFE was associated with the transcriptional regulation of the microphthalmia-associated transcription factor (MITF). PPFE inhibited the promoter activity of MITF and suppressed MITF mRNA expression in melan-a cells. These results indicate that PPFE down-regulates melanogenesis-associated gene expression through MITF-mediated transcriptional regulation and these events might be related to the hypopigmentary effects of PPFE.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1585-1590
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• 2007

Although a number of melanogenesis inhibitors have recently been reported and used as cosmetic additives, none is completely satisfactory, leaving a need for novel skin-depigmenting agents. Thus, to develop a novel skin depigmenting agent from natural sources, the inhibition of melanogenesis by Chinese plants was evaluated. A methanolic extract of Nigella glandulifera Freyn was found to inhibit the melanin synthesis of murine B16F10 melanoma cells by 43.7% and exhibited a low cytotoxicity (8.1%) at a concentration of $100\;{\mu}g/ml$. Thus, to identify the melanogenesis-inhibiting mechanism, the inhibitory activity towards tyrosinase, the key enzyme of melanogenesis, was further evaluated, and the results showed inhibitory effects on the activity of intracellular tyrosinase yet not on mushroom tyrosinase. Finally, to isolate the compounds with a hypopigmenting capability, activity-guided isolation was performed, and Dioctyl phthalate identified as inhibiting melanogenesis.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.666-668
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• 2014

• Korean Journal of Pharmacognosy
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• v.36 no.1 s.140
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• pp.60-63
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• 2005

One sesquiterpenoid was isolated from the methanol extract of Atractylodes rhizomes which has been used as traditional medicine for diuresis and the compound was established as selina-4(14),7(11)-dien-8-one by the spectroscopic methods. The compound$(IC_{50}<10\;ppm)$ has inhibitory effects on melanogenesis in B16 mouse melanoma.

• Korean Journal of Pharmacognosy
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• v.38 no.4
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• pp.382-386
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• 2007

Cinnamomi Cortex (Lauraceae), the dried bark of Cinnamomum cassia BLUME, has been used as traditional Chinese medicine for its stomachic, astringent, carminative, antispasmodic, antibacterial, antifungal properties. Four compounds were isolated from the MeOH extract of Cinnamomi Cortex, and their structures were identified as trans-cinnamic acid (1), ${\beta}-sitosterol$ (2), bis(2-methylheptyl)phthalate (3), coumarin (4) by comparison of their physical and spectral data with those reported in the literature. These compounds were tested melanogenesis inhibitory effect on B-16 mouse melanoma cell lines. Among them, trans-cinnamic acid (1) showed the most potent inhibitory effect on melanogenesis with $IC_{50}$ value of $13{\mu}g/ml$. Arbutin, positive control, exhibited an $IC_{50}$ value of $29{\mu}g/ml$.