• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.3 s.52
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• pp.265-271
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• 2005

This study is performed to investigate the effects of citrus essential oils on melanin production in B16 melanoma cells and reactive oxygen species (ROS) generation in RBL 2H3 cells. Five kinds of citrus essential oil (bergamot, grapefruit, lemmon, mandarin, petigrain) did not have any influence on DPPH radical scavenger activity, cell growth and cytotoxicity in B16 melanoma cells. In purified tyrosinase assay, both mandarin and petigrain essential oils dose-dependently inhibited its activity, but bergamot did not. In $1{\mu}M\;{\alpha}-MSH-stimulated$ B16 melanoma cells, all of 5 citrus essential oils inhibited melanin production in $\underline{a}$ dose dependent manner. On the other hand, four kinds of citrus essential oil dose-dependently increased ROS generation in RBL 2H3 mast cells, but mandarin did not. From the above results, it is possible that citrus essential oils nay be developed to be anti-melanogenic agent on the basis of their inhibitory effect on MSH-induced melanin production. Hut we can not rule out the possibility of the induction of allergy and inflammation since citrus essential oils caused ROS generation in RBL 2H3 mast cells.

• Fashion & Textile Research Journal
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• v.8 no.3
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• pp.326-330
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• 2006

The results of the research for the whitening effect and functional machanism of 1-(2-cyclohexylmethoxy-6-hydroxyphenyl)-3-(4-hydroxymethylphenyl)-propenone are as follow : 1. Propenone inhibited concentration-dependently the generation of melanin increased by the stimulation of ${\alpha}$-MSH and protoporphyrin IX, and $IC_{50}$ value was six to eight ${\mu}M$. This was five to seven times superior in the inhibiting effect, compared with kojic acid used as positive control group. 2. Propenone did not have a decolorizing effect on melanin already generated. 3. Propenone was observed to have toxicity of over $100{\mu}M$ for the mouse melanoma B16 cells.

• 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.

• Korean Journal of Veterinary Research
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• v.58 no.2
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• pp.65-72
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• 2018

The present study observed the effects of a green tea (Camellia sinensis) flower extract (GTFE) on melanin synthesis in B16-F10 melanoma cells. GTFE exhibited antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl and inhibited mushroom tyrosinase activity in a dose-dependent manner. Furthermore, GTFE significantly diminished ${\alpha}-melanocyte$ stimulating hormone (${\alpha}-MSH$) stimulated cellular melanin content and tyrosinase activity throughout the concentration range evaluated. Based on RNA sequencing analysis, differential gene expression patterns observed in ${\alpha}-MSH$ stimulated B16-F10 melanoma cells were normalized by the addition of GTFE. In particular, the expression levels of melanoregulin and tyrosinase genes which are key regulating genes in melanin synthesis were up-regulated by 3.5 and 3 fold respectively by ${\alpha}-MSH$, and were normalized to control levels by the addition of GTFE. The results suggest that GTFE inhibits melanin synthesis in ${\alpha}-MSH$ stimulated B16-F10 melanoma cells by normalizing expression of genes that are essential for melanin synthesis. Overall, the results suggest that GTFE could be applied in the development of a whitening agent for the treatment of dermal hyperpigmentation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.295-304
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• 2005

Recently, arbutin, oil soluble licorice extact (GLY), ascorbyl glucoside (AA2G), and ethyl ascorbyl ether (EAE) have been widely used as functional whitening ingredients. To Investigate which combination between the above agents could be more effective for whitening effect, tyrosinase activity and MSH-induced melanin production in B-16 melanoma cells were investigated. Both GLY and arbutin dose-dependently inhibited purified tyrosinase activity. The inhibitory effects of GLY with AA2A or EAE on Drosinase activity were more potent than those of GLY alone, whereas that of arbutin with other ingreadients did not show those effects. In MSH-induced melanin production in B-16 melanoma cells, the mixture of Gly and EAE more significantly reduced melanin formation than Gly alone. Stability of mixture of GLY, arbutin, AA2A and EAE exposed at the temperature of $25^{\circ}C\;or\;45^{\circ}C$ for 30 days were also investigated. All of the combinations of whitening agents did not show any critical changes in their composition stability. These data suggest that the combination of GLY and vitamin C derivatives such as AA2G and EAE may be useful for the promotion of whitening effect.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2587-2592
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• 2016

Background: Early onset sporadic colorectal cancer (CRC) is a biologically and clinically distinct entity hypothesized to exhibit differences in histological features and microsatellite instability (MSI) as compared to typical onset CRC. This study compared the MSI status, mismatch repair enzyme deficiency and clinicopathological features of early onset (aged ${\leq}45$ years) with controls (>45 years). Materials and Methods: A total of 30 cases and 30 controls were analyzed for MSI status using the Bethesda marker panel. Using antibodies against hMLH1, hMSH2 and hMSH6, mismatch repair protein expression was assessed by immunohistochemistry. Molecular characteristics were correlated with clinicopathological features. Results: The early onset sporadic CRCs were significantly more poorly differentiated tumors, with higher N2 nodal involvement and greater frequency of signet ring phenotype than the typical onset cases. MSI was observed in 18/30 cases, with 12/18 designated as MSI-high (MSI-H) and 6/18 designated as MSI-low (MSI-L). In the control group, 14 patients exhibited MSI, with 7 MSI-H and 7 MSI-L. MSI tumors in both cases and controls exhibited loss of hMLH1, hMSH2 and hMSH6. MSS tumors did not exhibit loss of expression of MMR proteins, except hMLH1 protein in 3 controls. No statistically significant difference was noted in MSI status or expression of MMR proteins in cases versus controls. Conclusions: Microsatellite status is comparable between early and typical onset sporadic CRC patients in Pakistan suggesting that differences in clinicopathological features between these two subsets are attributable to other molecular mechanisms.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.28 no.1
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• pp.41-52
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• 2015

Objective : This study investigated the inhibitory mechanism of the hypopigmentating effects on ethanol extract of Rosae rugosae Flos (ERR) that has not yet been examined. Methods : We analyzed the anti-melanogenic effects of ethanol extracts from Rosae rugosae Flos by tyrosinase activity, melanin contents. We also examined protein expression levels of tyrosinase, TRP-1, TRP-2, MITF and ERK by western blot analysis in melanoma cells. Results : In this investigation, ERR effectively reduced ${\alpha}$-MSH-stimulated melanin synthesis by suppressing expression of tyrosinase and tyrosinase-related protein-1 (TRP-1). On the other hand, the expression of tyrosinase-related protein-2 (TRP-2) were not affected by treatment with ERR. ERR inhibited the expression of microphthalmia-associated transcription factor (MITF) as a key transcription factor for tyrosinase expression regulating melanogenesis. The upstream signaling pathway including cAMP response element-binding protein (CREB) and MAPKs were also inhibited by ERR. Pretreatment with PD98059, ERK inhibitor, attenuated the inhibitory effect of ERR on ${\alpha}$-MSH-induced tyrosinase activity. Conclusions : Our study suggested that the anti-melanogenic activity of ERR is correlated with the suppression of tyrosinase gene through CREB/MITF/ERK pathway.

• Molecules and Cells
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• v.38 no.1
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• pp.33-39
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• 2015

The correction of disease-causing mutations by single-strand oligonucleotide-templated DNA repair (ssOR) is an attractive approach to gene therapy, but major improvements in ssOR efficiency and consistency are needed. The mechanism of ssOR is poorly understood but may involve annealing of oligonucleotides to transiently exposed single-stranded regions in the target duplex. In bacteria and yeast it has been shown that ssOR is promoted by expression of $Red{\beta}$, a single-strand DNA annealing protein from bacteriophage lambda. Here we show that $Red{\beta}$ expression is well tolerated in a human cell line where it consistently promotes ssOR. By use of short interfering RNA, we also show that ssOR is stimulated by the transient depletion of the endogenous DNA mismatch repair protein MSH2. Furthermore, we find that the effects of $Red{\beta}$ expression and MSH2 depletion on ssOR can be combined with a degree of cooperativity. These results suggest that oligonucleotide annealing and mismatch recognition are distinct but interdependent events in ssOR that can be usefully modulated in gene correction strategies.

• Journal of Applied Biological Chemistry
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• v.65 no.2
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• pp.93-99
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• 2022

Lysosome organelle extract (LOE) was derived from egg whites. The lysosome is an intracellular organelle that contains several hydrolysis enzymes. Previous studies have reported that LOE performs important functions, such as melanin de-colorization and anti-melanin production in B16F10 melanoma cells. However, its principal molecular and cellular mechanisms have not been elucidated till date. In non-cytotoxic conditions, LOE significantly inhibited α-MSH induced melanin synthesis of murine B16F10 cells. The anti-melanogenic activity of LOE was mediated by suppressing the mRNA expression of tyrosinase enzyme, tyrosinase related protein-1/2 (TRP-1/2), and microphthalmia-associated transcription factor (MITF) genes. By performing western blot analysis, we found that LOE significantly attenuated melanogenesis. In this case, LOE helped in increasing extracellular receptor kinase (ERK) phosphorylation in α-MSH induced B16F10 cells. Furthermore, MITF is found to be a key regulatory transcription factor in melanin synthesis; it was down-regulated by LOE through ERK phosphorylation. In this experiment, PD98059 (MEK inhibitor) was used to check whether LOE directly regulated the activity of ERK. Although LOE exerted inhibitory effect on melanin synthesis, we could not observe this effect in PD98059-treated α-MSH induced B16F10. These results strongly indicate that LOE is related to ERK activation and MITF degradation in anti-skin pigmentation. Hence, LOE should be utilized as a whitening agent of skin in the near future.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.155-159
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• 2016

Previous research showed that resveratrol (trans-3,4',5-trihydroxystilbene) and pinostilbene (trans-3-methoxy-4',5-dihydroxystilbene) were able to inhibit tyrosinase directly; however, anti-melanogenic effects of pterostilbene (trans-3,5-dimethoxy-4'-hydroxystilbene) and resveratrol trimethyl ether (RTE) have not been compared. To investigate the hypopigmentation effects of pterostilbene and RTE, melanin contents and intracellular tyrosinase activity were determined by western blot analysis. Firstly, pterostilbene showed the inhibitory effects on ${\alpha}$-melanocyte stimulating hormone (MSH)-induced melanin synthesis stronger than RTE, resveratrol, and arbutin. Pterostilbene inhibited melanin biosynthesis in a dose-dependent manner in ${\alpha}$-MSH-stimulated B16/F10 murine melanoma cells. Specifically, melanin content and intracellular tyrosinase activity were inhibited by 63% and 58%, respectively, in response to treatment with $10{\mu}m$ of pterostilbene. The results of western blot analysis indicated that pterostilbene induced downregulation of tyrosinase protein expression and suppression of ${\alpha}$-MSH-stimulated melan-A protein expression stronger than RTE or resveratrol. Based on these results, our study suggests that pterostilbene can induce hypopigmentation effects more effectively than resveratrol and RTE, and it functions via downregulation of protein expression associated with hyperpigmentation in ${\alpha}$-MSH-triggered B16/F10 murine melanoma cells.