• Korean Journal of Korean Medical Institute of Dermatology and Aesthetics
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• v.1 no.1
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• pp.91-97
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• 2005

(1) Objectives: To discover natural skin-lightening agents, we have evaluated the inhibitory activity of EtOH extracts from 20 medicinal plants against mushroom tyrosinase. (2) Methods: Tyrosinase activity was determined by the dopachrome method using L-tyrosine as the substrates. (3) Results: Of the plant extracts tested, the extracts of 4 plants, Albizzia julibrissin, Curcuma longa, Anethum graveolens and Sophora flavescens, exhibited potent inhibitory activity (> 50%) in mushroom tyrosinase assay. Four plant extract, extracts of Agrimonia pilosa, Paeonia moutan, Magnolia obovata and Eugenia caryophyllata also showed relatively strong inhibitory (> 40%) against mushroom tyrosinase. (4) Conclusion: These active medicinal plants may be useful for the development of skin-whitening agents. Since the active medicinal plants may contain effective tyrosinase inhibitors even more than kojic acid, further study to identify the active constituents from the plants is expected.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.820-829
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• 2003

One of the important function of skin is the protection from harmful environments. Many studies were carried out to keep the skin from wrinkling and pigmenting. Skin wrinkle and pigmentation could be caused' by the unusual disruption of connective tissue, the formation of free radicals and the radiation of ultraviolet. In this study, the extracts obtained from 23 different kinds of medicinal plants were examined whether they have inhibitory effect on tyrosinase and elastase as well as free radical scavenging effect. All the extracts examined were obtained by using 70% (v/v) ethanol at $60^{\circ}C$. It has been found that there were two medicinal plants which have positive effects matching with the purpose of this study. The extract of Ephedra sinica stapf shows an inhibitory effect on tyrosinase ($IC_{50}$ = 83.7~$\mu\textrm{g}$/ml), on elastase ($IC_{50}$ = $690{\mu}\textrm{g}$/ml), and also shows free radical scavenging effect ($IC_{50}$ = 29.6$\mu\textrm{g}$/ml). The extract of Betula platyphylla Var. shows an inhibitory effect on elastase ($IC_{50}$ = 498.1$\mu\textrm{g}$/ml), and free radical scavenging effect ($IC_{50}$ = 9$\mu\textrm{g}$/ ml). The aim of the study is to find the natural compounds which have function in skin-lightening, anti-wrinkling and anti-oxidation, with safe and active ingredients in cosmetic.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.232-237
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• 1999

The standardization urban transit project has been started by government and the Korean standard electrical railcar has been designed. The bodyshell of standard railcar is made of aluminium alloy. In the present paper, the design of its bodyshell is evaluated in the viewpoint of strength analysis. The loading condition is based on the 'Test Methods of Static Load for Body Structure of Electrical Multiple Unit', standard specification. The bodyshell of Korean standard EMU consist of longitudinal extrusion members which are double-skin structure type. For the purpose of security and lightening we decided the section of the aluminium carbody through the size optimization in this paper Hereafter this paper will contribute to the shape optimization.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2011.10a
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• pp.16-16
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• 2011

Melanogenesis is a well-known physiological response of human skin that may occur because of exposure to ultraviolet light, for genetic reasons, or due to other causes. In our effectors to find new skin lightening agents, acanthoic acid (AA) was investigated for its ability to inhibit melanogenesis. The effects of AA isolated from A.koreanumun the expression of $\alpha$-MSH-induced melanogenic factors (tyrosinase, tyrosinase related protein (TRP)-1, TRP-2 and MITF (microphthalmla-associated transcriptional factor)) were investigated in murine B16F10 melanoma cells. The results indicate that AA was an effective inhibitor of melanogenesis in B16F10 cells. To elucidate the mechanism of the effect of AA on melanogenesis, we performed Western blotting for melanogenic proteins. AA inhibited melanogenic factors (tyrosinase, TRP-1, TRP-2) expressions. In this study, we also confirmed that AA decreased the protein level of MITF proteins, which would lead to a decrease of tyrosinase and related genes in B16F10 melanoma cells. In order to apply AA to the human skin, the cytotoxic effects of the AA were determined by MTT assays using human keratinocyte HaCaT cells. Based on these results, we suggest that AA be considered possible anti-melanogenic agent and might be effective against hyperpigmentation disorders for the topical application.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.28 no.2
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• pp.1-12
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• 2015

Objective : The goal of this study is to identify the effects of extract ofGentianae sino-ornata(GSO) on the anti-oxidative activity of skin.For this purpose, several functions of GSO were analyzed in terms of skin-lightening activity and wrinkle improvement. Methods : Cell viability was measured by neutral red (NR) assay, and GSO showed highly efficacy in DPPH radical scavenging activity. The level of tyrosinase and matrix metalloproteinase-1 (MMP-1) in media was analyzed by ELISA kit, and the expressions of p-JNK and p-ERK was measured by Western blot. To elucidate inhibitory effects of GSO on melanin synthesis, I determined the tyrosinase activity and melanin production in B16F10 cells. Results : MMP-1 production in UVB-stimulated HDF cells was inhibited by GSO treatments, and also GSO inhibited protein expression levels of p-JNK and p-ERK. GSO significantly reduced tyrosinase activity and melanin synthesis in B16F10 cells. Conclusions : From these results, GSO appears to be effective on skin elasticity increase, wrinkle improvement, whitening as anti-aging activity.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.1
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• pp.29-32
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• 2004

Inhibition of the early N-glycosylation process in the endoplasmic reticulum prevents the activation of tyrosinase, a key enzyme for melanin biosynthesis. This work aims at evaluating the increased activity of N-glycosylation inhibitors in vitro b, employing a nano-sized pH-sensitive liposome as a delivery carrier. Melexsome, a pH-sensitive nano carrier loaded with glycosylation inhibitos, was prepared by the hydration method with phospholipids and cholresterol-based amphiphiles. Inhibitory effects of Melexsome on the N-glycosylation process were evaluated by EndoH ＆ PNGaseF digestion and the western blotting. Melanin synthesis was also monitored after treatment with Melexsome Interestingly, Melexsome effectively increased the efficacy of N-glycosylation inhibitors. Melexsome was also much more efficiently translocated into the cytoplasm as observed in CLSM. These results demonstrated that the amphiphilic lipid-based pH-sensitive nano-carriers could be, used as an efficient delivery system for N-glycosylation inhibitor to enhance the effects of skin whitening cosmetics.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.2
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• pp.149-156
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• 2020

Sodium 2-mercaptoethanesulfonate (mesna) is a protective agent that is widely used in medicine because of its antioxidant effects. Recently, reactive oxygen species (ROS) were shown to increase pigmentation. Thus, ROS scavengers and inhibitors of ROS production may suppress melanogenesis. Forkhead box-O3a (FoxO3a) is an antimelanogenic factor that mediates ROS-induced skin pigmentation. In this study, we aimed to investigate the whitening effect of mesna and the signaling mechanism mediating this effect. Human melanoma (MNT-1) cells were used in this study. mRNA and protein expression were measured by real-time quantitative PCR and Western blotting analysis to track changes in FoxO3a-related signals induced by mesna. An immunofluorescence assay was performed to determine the nuclear translocation of FoxO3a. When MNT-1 melanoma cells were treated with mesna, melanin production and secretion decreased. These effects were accompanied by increases in FoxO3a activation and nuclear translocation, resulting in downregulation of four master genes of melanogenesis: MITF, TYR, TRP1, and TRP2. We found that mesna, an antioxidant and radical scavenger, suppresses melanin production and may therefore be a useful agent for the clinical treatment of hyperpigmentation disorders.

• 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 the Society of Cosmetic Scientists of Korea
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• v.40 no.1
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• pp.89-94
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• 2014

Stem bark extracts of Fraxinus rhynchophylla Hance were found to contain two major bioactive components, esculetin and esculin. Esculetin substantially inhibited melanogenesis in B16F10 melanoma cells, with an $IC_{50}$ value of $2.8{\mu}M$, and reduced melanin synthesis in Melan-A cells. Moreover, esculetin suppressed melanin biosynthesis by inhibiting mushroom tyrosinase activity, with an $IC_{50}$ value of $40{\mu}M$. Taken together, these results suggest that esculetin could serve as an effective skin-lightening agent that inhibits melanin production by regulating the activity of melanogenic enzymes.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.120-121
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• 2006

In this paper, We have designed a face recognition system based on the embedded Linux. This paper has an aim in embedded system to recognize the face more exactly. At first, the contrast of the face image is adjusted with lightening compensation method, the skin and lip color is founded based on YCbCr values from the compensated image. To take advantage of the method based on feature and appearance, these methods are applied to the eyes which has the most highly recognition rate of all the part of the human face. For eyes detecting, which is the most important component of the face recognition, we calculate the horizontal gradient of the face image and the maximum value. This part of the face is resized for fitting the eye image. The image, which is resized for fit to the eye image stored to be compared, is extracted to be the feature vectors using the continuous wavelet transform and these vectors are decided to be whether the same person or not with PNN, to miminize the error rate, the accuracy is analyzed due to the rotation or movement of the face. Also last part of this paper we represent many cases to prove the algorithm contains the feature vector extraction and accuracy of the comparison method.