Chang-Gu Hyun

Jeju National University, Tse-tsiu, Jeju-do, South Korea

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Publications (62)70.67 Total impact

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    ABSTRACT: In order to test the effectiveness of tangeretin at ameliorating melanoma and melanoma-associated depigmentation, western blotting was used to assess the melanin content of treated melanoma cells. Tangeretin, a 4',5,6,7,8-pentamethoxyflavone, was found to trigger intracellular melanin production in a concentration-dependent manner in B16/F10 murine melanoma cells. Melanin content increased 1.74-fold in response to treatment with 25 μM of tangeretin, compared to that in non-treated cells. Examination of melanogenic protein expression showed that tyrosinase, tyrosinase-related protein (TRP)-1, and extracellular signal-regulated kinase (ERK) 1/2 levels increased in a dose-dependent manner. Furthermore, the expression of cyclic adenosine monophosphate response element binding protein (CREB) and microphthalmia transcription factor (MITF) was increased by tangeretin in 1 h and 4 h, respectively. Tangeretin- upregulated melanogenesis was suppressed by ERK 1/2 inhibitor and not by ERK1 inhibitor. These results suggest that tangeretin has therapeutic potential for melanoma and melanoma-associated depigmentation because it can induce hyperpigmentation through the activation of melanogenic signaling proteins and initiation of sustained ERK2 expression.
    Natural product communications 03/2015; 10(3):389-92. · 0.92 Impact Factor
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    ABSTRACT: As an approach to search for chemopreventive agents, we tested p-coumaric acid, 3-methoxy-p-coumaric acid (ferulic acid), and 3,5-dimethoxy-p-coumaric acid (sinapic acid) in B16/F10 melanoma cells. Intracellular melanin contents were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and cytotoxicity of the compounds were examined by lactate dehydrogenase (LDH) release. p-Coumaric acid showed inhibitory effect on melanogenesis, but ferulic acid increased melanin content, and sinapic acid had almost no effect on melanogenesis. Treatment with ferulic acid resulted in a 2 to 3 fold elevation in the production of melanin. Correlatively, cell viability decreased in a dose-dependent manner when treated with ferulic acid. However, ferulic acid did not affect the LDH release from the cells. Treatment with sinapic acid resulted in a 50~60% elevation in the release of LDH when treated with a 200 μg/mL concentration and showed neither cytostasis nor increase of melanin synthesis in a dose-dependent manner. Taken together, p-coumaric acid inhibits melanogenesis, ferulic acid induces melanogenesis, and sinapic acid exerts cytotoxic effects in B16/F10 murine melanoma cells. The results indicate that the addition of methoxy groups to p-coumaric acid shows the melanogenic or cytotoxic effects in melanoma cells compared to the original compound. Therefore, this study suggests the possibility that methoxylated p-coumaric acid, ferulic acid can be used as a chemopreventive agent.
    03/2015; 20(1):73-7. DOI:10.3746/pnf.2015.20.1.73
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    ABSTRACT: In the present study, 2,4,6-trihydroxybenzaldehyde (THB) was evaluated for inhibitory effects on adipocyte differentiation in 3T3-L1 cells and anti-obesity effects in mice with high-fat diet (HFD)-induced obesity. Lipid accumulation measurement indicated that THB markedly inhibited adipogenesis, and this involved down-regulation of the expression of the adipogenesis-related proteins, CCAAT/enhancer-binding protein α (C/EBPα), peroxisome proliferator-activated receptor γ (PPARγ), fatty acid synthase (FAS) and sterol regulatory element-binding protein-1c (SREBP-1c), in 3T3-L1 pre-adipocyte cells. In a mouse model of HFD-induced obesity, oral administration of THB (5 and 25mg/kg for 13 weeks) reduced the HFD-induced increase in weight gain. THB administration also reduced serum levels of glucose, triglycerides, and total cholesterol. A reduction in the hypertrophy of white adipose tissue was also observed. Furthermore, THB administration inhibited HFD-induced hepatic steatosis. These results provided evidence that administration of THB alleviated HFD-induced obesity in C57BL/6 mice and revealed the potential of THB as a nutraceutical to help prevent or treat obesity and the associated metabolic disorders. Copyright © 2015 Elsevier B.V. All rights reserved.
    Environmental Toxicology and Pharmacology 02/2015; 7(2). DOI:10.1016/j.etap.2015.02.007 · 1.86 Impact Factor
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    ABSTRACT: The ethanol extract of Tilia taquetii Schneider leaves was investigated for its anti-wrinkle properties and for the relevant chemical constituents. Phytochemical studies led to the identification of five known compounds, viz. phytol (1), isoquercitrin (2), oleanderolide (3), arjunolic acid (4) and maslinic acid (5) from the extract. Of these, compounds 4 and 5 inhibited the expression of matrix metalloproteinase-1 (MMP-1), an enzyme responsible for the breakdown of collagen fiber. Moreover, compound 5 showed inhibition activity on elastase, a protease enzyme capable of degrading elastin. These results suggest that the extract of T. taquetii containing the triterpenes 4 and 5 could be applied as anti-wrinkle ingredients in cosmetic preparations.
    Natural product communications 12/2014; 9(12):1683-5. · 0.92 Impact Factor
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    ABSTRACT: To investigate the anti-inflammatory effects of Jeju seaweeds on macrophage RAW 264.7 cells under lipopolysaccharide (LPS) stimulation.
    Asian Pacific Journal of Tropical Biomedicine 07/2014; 4(7):529-37. DOI:10.12980/APJTB.4.2014C1099
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    ABSTRACT: A number of seaweed species are used as traditional foods and medicine in different parts of the world, including Asian countries. However, very few data on the anti-melanogenic effect of seaweed have been published. Undaria pinnatifida (Dolmiyeok), a brown alga, is a traditional food in Jeju Island, the southern regions of the Korea peninsula. In this study, ethylacetate extracts of U. pinnatifida (UPE) were examined for their anti-melanogenic potentials. Our results supports the finding that UPE down-regulated melanin content in a dose-dependent pattern. To clarify the target of UPE action in melanogenesis, we performed Western blotting for tyrosinase and microphthalmia-associated transcription factor (MITF), which are key melanogenic enzymes. UPE inhibited tyrosinase and MITF expressions in a dose-dependent manner. These results indicate that treatment with UPE significantly inhibits the melanogenesis in B16 cells, and may be effective in the whitening agent for the skin.
    Interdisciplinary toxicology 06/2014; 7(2):89-92. DOI:10.2478/intox-2014-0012
  • Journal of the Korean Society of Food Science and Nutrition 05/2014; 43(5):705-711. DOI:10.3746/jkfn.2014.43.5.705
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    ABSTRACT: Though many essential oils from citrus peels are claimed to have several medicinal functions, the chemical composition and biological activities of the essential oils of Citrus flowers have not been well described. Therefore, this study intended to investigate the chemical composition and anti-inflammatory potential of essential oils from C. unshiu flower (CEO) to support its purported beneficial health effects. The chemical constituents of the CEO, analyzed by gas chromatography-mass spectrometry (GC-MS), included y-terpinene (24.7%), 2-beta-pinene (16.6%), 1-methyl-2-isopropylbenzene (11.5%), L-limonene (5.7%), beta3-ocimene (5.6%), and alpha-pinene (4.7%). The effects of the CEO on nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were also examined. The results indicate that the CEO is an effective inhibitor of LPS-induced NO and PGE2 production in RAW 264.7 cells. Additionally, CEO was shown to suppress the production of inflammatory cytokines including interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and IL-6. Based on these results, CEO may be considered a potential anti-inflammatory candidate with human health benefits.
    Natural product communications 05/2014; 9(5):727-30. · 0.92 Impact Factor
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    ABSTRACT: The aim of this study was to investigate the in vitro inhibitory effects of acanthoic acid (ACAN), isolated from Acanthopanax koreanum, on melanogenesis and its related enzymes such as tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 in B16 melanoma cells. We found that ACAN significantly attenuates melanin synthesis and reduces the activity of intracellular tyrosinase, the rate-limiting melanogenic enzyme. Western blot analysis showed that ACAN also decreases tyrosinase, TRP-1, and TRP-2 protein expression. In addition, ACAN significantly decreased the expression of microphthalmia-associated transcription factor (MITF), a key regulator of melanogenesis. These results indicate that ACAN effectively inhibits melanin biosynthesis through down-regulation of MITF and thus could be useful as a new skin-whitening agent.
    Natural product communications 10/2013; 8(10):1359-62. · 0.92 Impact Factor
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    ABSTRACT: During our ongoing screening program designed to determine the anti-inflammatory potential of natural compounds, we isolated sargachromenol from Sargassum micracanthum. In the present study, we investigated the anti-inflammatory effects of sargachromenol on lipopolysaccharide (LPS)-induced inflammation in murine RAW 264.7 macrophage cells and the underlying mechanisms. Sargachromenol significantly inhibited the LPS-induced production of nitric oxide (NO) and prostaglandin E2 (PGE2) in a dose-dependent manner. It also significantly inhibited the protein expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose-dependent manner in LPS-stimulated macrophage cells. Further analyses showed that sargachromenol decreased the cytoplasmic loss of inhibitor κ B α (I κ B α ) protein. These results suggest that sargachromenol may exert its anti-inflammatory effects on LPS-stimulated macrophage cells by inhibiting the activation of the NF- κ B signaling pathway. In conclusion, to our knowledge, this is the first study to show that sargachromenol isolated from S. micracanthum has an effective anti-inflammatory activity. Therefore, sargachromenol might be useful for cosmetic, food, or medical applications requiring anti-inflammatory properties.
    The Scientific World Journal 09/2013; 2013:712303. DOI:10.1155/2013/712303 · 1.73 Impact Factor
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    ABSTRACT: To investigate the suitability of citrus-press cakes, by-products of the juice industry as a source for the whitening agents for cosmetic industry. Ethylacetate extracts of citrus-press cakes (CCE) were examined for their anti-melanogenic potentials in terms of the inhibition of melanin production and mechanisim of melanogenesis by using Western Blot analysis with tyrosinese, tyrosinase-related protein-1 (TRP-1), TRP2, and microphthalmia-associated transcription factor (MITF) proteins. To apply the topical agents, citrus-press cakes was investigated the safety in human skin cell line. Finally flavonoid analysis of CCE was also determined by HPLC analysis. Results indicated that CCE were shown to down-regulate melanin content in a dose-dependent pattern. The CCE inhibited tyrosinase, TRP-2, and MITF expressions in a dose-dependent manner. To test the applicability of CCE to human skin, we used MTT assay to assess the cytotoxic effects of CCE on human keratinocyte HaCaT cells. The CCE exhibited low cytotoxicity at 50 µg/mL. Characterization of the citrus-press cakes for flavonoid contents using HPLC showed varied quantity of rutin, narirutin, and hesperidin. Considering the anti-melanogenic activity and human safety, CCE is considered as a potential anti-melanogenic agent and may be effective for topical application for treating hyperpigmentation disorders.
    Asian Pacific Journal of Tropical Biomedicine 08/2013; 3(8):617-22. DOI:10.1016/S2221-1691(13)60125-2
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    ABSTRACT: The marine environment is a unique source of bioactive natural products, of which Sargassum muticum (Yendo) Fensholt is an important brown algae distributed in Jeju Island, Korea. S. muticum is a traditional Korean food stuff and has pharmacological functions including anti-inflammatory effects. However, the active ingredients from S. muticum have not been characterized. Bioguided fractionation of the ethanolic extract of S. muticum, collected from Jeju island, led to the isolation of a norisoprenoid. Its structure was determined by analysis of the spectroscopic data. In vitro anti-inflammatory activity and mechanisms of action of this compound were examined using lipopolysaccharide (LPS)-stimulated RAW 264.7 cells through ELISA assays and Western blot analysis. Apo-9[prime]-fucoxanthinone, belonging to the norisoprenoid family were identified. Apo-9[prime]-fucoxanthinone effectively suppressed LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production. This compound also exerted their anti-inflammatory actions by down-regulating of NF-kappaB activation via suppression of IkappaB-alpha in macrophages. This is the first report describing effective anti-inflammatory activity for apo-9[prime]-fucoxanthnone isolated from S. muticum. Apo-9[prime]-fucoxanthinone may be a good candidate for delaying the progression of human inflammatory diseases and warrants further studies.
    DARU-JOURNAL OF FACULTY OF PHARMACY 07/2013; 21(1):62. DOI:10.1186/2008-2231-21-62 · 1.11 Impact Factor
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    ABSTRACT: This study was conducted to identify the anti-melanogenesis constituents from a seaweed Dictyota coriacea (Holmes). Three known compounds, viz. 1,9-dihydroxycrenulide (1), epiloliolide (2) and D-mannitol (3), were isolated from the ethanol extract. The melanin synthesis inhibition activities were evaluated using B16F10 melanoma cells for the isolates. Compared with the positive control, arbutin, compounds 1 and 2 exhibited more potency, showing 27.8 and 22.6% inhibition activities at a substrate concentration of 30 microg/mL. Our studies also indicate that these compounds are not cytotoxic. Hence, they might prove to be useful therapeutic agents for treating hyperpigmentation and effective components of whitening cosmetics.
    Natural product communications 04/2013; 8(4):427-8. · 0.92 Impact Factor
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    ABSTRACT: Essential oils, volatile compounds from plants, are attractive natural ingredients possessing wide range of applications in cosmetics, foods, household products and alternative medicines. In this study, the three different oils from Prunus yedoensis (PYE), Saururus chinensis (SCE), Zanthoxylum piperitum (ZPE) were prepared by supercritical carbon dioxide extraction and their chemical components were analyzed. In addition, their anti-inflammatory activities were investigated by measuring the inhibition of pro-inflammatory cytokines. Monoteipenes alpha-Pinene (22.4%), 2-beta-pinene (20.1%) and camphor (13.1%) were found as the major components in PYE. In the case of SCE, sesquiterpenes delta-cadinol (22.5%) and delta-cadinene (19.7%) as well as a diterpene trans-phytol (13.7%) were mainly identified. The major chemical constituents of ZYE were in the order of octanoic acid (13.4%), n-heptanol (9.8%) and 1-octanol (8.1%). As a bioactivity study, the effects of PYE, SCE and ZPE on nitric oxide (NO), tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta and IL-6 production in lipopolysaccharide-activated RAW 264.7 macrophages were examined. These essential oils (PYE, SCE, ZPE) were appeared to considerably suppress the production of pro-inflammatory cytokine and mediators in dose-dependent manner. The results indicate that PYE, SCE and ZPE can be useful natural agents to manage inflammatory symptoms and diseases.
    International Journal of Pharmacology 04/2013; 9(4):258-264. DOI:10.3923/ijp.2013.258.264 · 0.98 Impact Factor
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    ABSTRACT: Development of natural products possessing anti-inflammatory activities has been the focus of research in our laboratory. In this study, the extract from Carpinus turczaninowii branches was studied and their anti-inflammatory constituents were identified. The aqueous ethanol extract was fractionated successively to afford n-hexane, ethyl acetate, n-butanol and aqueous layers. Upon anti-inflammatory tests for Nitric Oxide (NO) production, using RAW 264.7 cells, the ethyl acetate fraction exhibited potent inhibitory activities without causing cell toxicities. The ethyl acetate fraction was subjected to further purification to isolate carpinontriol A and carpinontriol B as active constituents. These diarylheptanoid compounds were isolated for the first time from this plant. The isolates reduced the lipopolysaccharide (LPS)-induced secretion of NO and IL-6 productions in a dose-dependent manner in RAW 264.7 cells which indicates their anti-inflammatory effects. Based on these results, it was suggested that C. turczaninowii extracts containing carpinontriols A and B could be considered potential anti-inflammatory agents for pharmaceuticals or cosmetics.
    International Journal of Pharmacology 02/2013; 9(2):157-163. DOI:10.3923/ijp.2013.157.163 · 0.98 Impact Factor
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    ABSTRACT: Strain PB92(T) of Pedobacter agri, which belongs to the family Sphingobacteriaceae, was isolated from soil in the Republic of Korea. The draft genome of strain PB92(T) contains 5,141,552 bp, with a G+C content of 38.0%. This is the third genome sequencing project of the type strains among the Pedobacter species.
    Journal of bacteriology 07/2012; 194(14):3738. DOI:10.1128/JB.00627-12 · 2.69 Impact Factor
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    ABSTRACT: Chemical investigation to identify the antioxidative constituents from the stems of a tree Cleyera japonica Thunb. resulted in the isolation of seven compounds: catechin (1), catechin 3-O-alpha-L-rhamnopyranoside (2), epicatechin (3), taxifolin (4), taxifolin 3-O-alpha-L-arabinopyranoside (5), taxifolin 3-O-alpha-L-rhamnopyranoside (6) and proanthocyanidin A-1 (7). These isolates were studied for their scavenging activities against DPPH radical, hydroxyl radical and superoxide anion radicals using spectrophotometry and/or electron spin resonance. All isolates 1-7 exhibited more potent DPPH radical inhibition activities than the positive control, ascorbic acid. In the hydroxyl radical scavenging test, compound 7 (SC50 301.6 mu M) showed potent activity higher than ascorbic acid (SC50 859.7 mu M). All of the compounds 1-7 exhibited comparable activities to ascorbic acid for superoxide anion radical scavenging. These results demonstrated that C. japonica stem extracts could be potentially used as antioxidative agents in food or cosmetic applications.
    International Journal of Pharmacology 05/2012; 8(5):410-415. DOI:10.3923/ijp.2012.410.415 · 0.98 Impact Factor
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    ABSTRACT: This study was designed to investigate the mushroom tyrosinase inhibitory activity for the constituents isolated from Neolitsea aciculata. The stems of N. aciculata was extracted with aqueous ethanol and subjected to chromatographic separation, which led to the isolation of 11 compounds: methyl linoleate (1), catechin (2), epicatechin (3), afzelin-7-O-glucopyranoside (4), 2',3'-di-(p-coumaroyl)afzelin (5), 2'-p-coumaroylafzelin (6), feruloyl tyramine (7), β-sitosterol (8), daucosterol (9), oleic acid (10), and trilaurin (11). Their structures were elucidated on the basis of spectroscopic studies as well as by comparison with the data available in the literature. Among these isolates, compounds 5 and 6 were identified as potent mushroom tyrosinase inhibitors with IC(50) values of 0.067 and 0.080 mM, respectively. The inhibition kinetics, analysed by Lineweaver-Burk plots, indicated that compounds 5 and 6 are competitive tyrosinase inhibitors when using l-tyrosine as a substrate. Notably, compounds 1-11 were isolated for the first time from this plant. These results provide evidence that this plant might be a potential source of anti-melanogenesis agents.
    Journal of Enzyme Inhibition and Medicinal Chemistry 04/2012; DOI:10.3109/14756366.2012.670806 · 2.38 Impact Factor
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    ABSTRACT: 3-O-p-Coumaroyl-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-O-β-D-gulcopyranosylpropanol (ESQ10) is a naturally occurring phenylpropanoid derivative isolated from Sasa quelpaertensis (Gramineae). In the present study, we discovered that ESQ10 inhibits nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. ESQ10 attenuated LPS-induced synthesis of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in parallel and inhibited LPS-induced interleukin-6 production, as determined by an enzyme-linked immunosorbent assay in the macrophages. The mechanism of the antiinflammatory action of ESQ10, i.e., suppression of nuclear factor (NF)-κB and mitogen-activated protein kinase activation, has been documented. However, ESQ10 could not influence LPS-mediated IκB-α degradation and extracellular signal-regulated kinase/c-Jun amino-terminal kinase phosphorylation at concentrations of up to 373 µM. To test the potential application of ESQ10 as a topical material, we also conducted a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on human HaCaT keratinocytes as well as human dermal fibroblast cells. In this assay, ESQ10 did not induce cytotoxicity. Taken together, the results suggest that ESQ10 may be considered an antiinflammatory candidate for treating inflammatory and skin diseases.
    YAKUGAKU ZASSHI 10/2011; 131(6):961-7. DOI:10.1002/chin.201141264 · 0.31 Impact Factor
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    ABSTRACT: Twenty compounds were isolated from the ethanol extract of Distylium racemosum branches and their inhibitory activities on tyrosinase, elastase and free radicals evaluated. The isolated compounds were identified as dibenzofurans (1-4), abscisic acid (5), 6'-O-galloylsalidroside (6), catechin derivatives (7-11), gallic acid derivatives (12-14), tyrosol (15), flavonoids (16-18), lupeol (19) and 1,2,3,6-tetragalloylglucose (20). For study of tyrosinase inhibition activities, when compared with arbutin (IC(50) 48.8 μg/mL), four compounds (8, 11, 13, 17) showed higher activities, with IC(50) values of 4.8, 30.2, 40.5 and 37.7 μg/mL, respectively. For the elastase inhibition test, dibenzofuran 1 showed greater activity than the positive control, oleanolic acid (IC(50) 9.7 μg/mL), with an IC(50) of 7.7 μg/mL. In the studies on DPPH radical scavenging activities, five compounds (11, 12, 13, 14, 15) showed higher activities than ascorbic acid (IC(50) 5.0 μg/mL), with IC(50) values of 4.6, 3.9, 2.9, 3.8 and 4.7 μg/mL, respectively.
    Phytotherapy Research 10/2011; 25(10):1451-6. DOI:10.1002/ptr.3439 · 2.40 Impact Factor

Publication Stats

510 Citations
70.67 Total Impact Points

Institutions

  • 2008–2015
    • Jeju National University
      • • Faculty of Marine Biomedical Sciences
      • • Department of Chemistry
      Tse-tsiu, Jeju-do, South Korea
  • 2008–2010
    • Cheju Halla University
      Tse-tsiu, Jeju, South Korea
  • 2006
    • Myongji University
      • Division of Biosciences and Bioinformatics
      Seoul, Seoul, South Korea