Youngwan Seo

Korea Maritime and Ocean University, Busan, Busan, South Korea

Are you Youngwan Seo?

Claim your profile

Publications (85)161.11 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The inhibitory effect of three chromones 1-3 and two coumarins 4-5 on the production of nitric oxide (NO) was evaluated in LPS-induced RAW 264.7 macrophage cells. Among the compounds tested heterocarpin (1), a furochromone, significantly inhibited its production in a dose-dependent manner. In addition, heterocarpin suppressed prostaglandin E2 (PGE2) production and expression of cytokines such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6).
    Molecules 08/2015; 20(8):14474-86. DOI:10.3390/molecules200814474 · 2.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Osteoporosis, a prevalent bone disease in an aging population, is considered to be closely related to osteoblastogenesis and adipogenesis. As a part of an ongoing trend to develop natural substances that attenuate osteoporotic conditions, edible brown algae E. cava and its bioactive constituents were tested for their effects on adipogenic differentiation in 3T3-L1 fibroblasts and osteoblast differentiation in MC3T3-E1 pre-osteoblasts. Following an activity-based isolation, three phlorotannin derivatives, triphlorethol-A (1), eckol (2) and dieckol (3), were isolated. Anti-adipogenesis effect of phlorotannins at the concentration of 20 µM was observed by reduced lipid accumulation and the suppressed expression of adipogenic differentiation markers. In addition, isolated phlorotannins successfully enhanced the osteoblast differentiation as indicated by increased alkaline phosphatase activity along with raised levels of osteoblastogenesis indicators and intracellular calcification at the concentration of 20 µM. In conclusion, E. cava is suggested as a source for functional food ingredients, especially phlorotannin derivatives that can be utilized for extenuating osteoporosis and obesity.
    Archives of Pharmacal Research 07/2015; DOI:10.1007/s12272-015-0637-0 · 2.05 Impact Factor

  • 02/2015; 30(1):38-43. DOI:10.7841/ksbbj.2015.30.1.38
  • [Show abstract] [Hide abstract]
    ABSTRACT: Lack of bone formation-related health problems is a major problem for aging population in modern world. As a part of ongoing trend to develop natural substances that attenuate osteoporotic bone loss conditions, the effect of edible brown algae, Sargassum thunbergii and its active contents on adipogenic differentiation in 3T3-L1 fibroblasts and osteoblast differentiation in MC3T3-E1 pre-osteoblasts were evaluated. Sargassum thunbergii treatment significantly reduced the lipid accumulation and the expression of adipogenic differentiation markers such as peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α and sterol regulatory element binding protein 1c. In addition, S. thunbergii successfully enhanced the osteoblast differentiation as indicated by increased alkaline phosphatase activity along raised levels of osteoblastogenesis indicators, namely bone morphogenetic protein-2, osteocalcin and collagen type I. Two compounds, sargaquinoic and sargahydroquinoic acid, were isolated from active extract and shown to be active by means of osteogenesis inducement. In conclusion, S. thunbergii could be a source for functional food ingredients for improved osteoporosis and obesity. This article is protected by copyright. All rights reserved.
    Journal of the Science of Food and Agriculture 02/2015; DOI:10.1002/jsfa.7148 · 1.71 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Several reports promoted the potential of shellfish due to their ability to act as antioxidant, anti-inflammatory, and antimicrobial agents. Pacific abalone, Haliotis discus hannai viscera is, reported to possess bioactivities such as antioxidative stress and anti-inflammatory. In this study, anti-inflammatory potential of mucus-secreting glands from shell-shucking waste of H. discus hannai was evaluated using RAW 264.7 mouse macrophage cell model. Results indicated that presence of H. discus hannai mucosubstance by-products (AM) significantly lowered the nitric oxide (NO) production along the expressional suppression of inflammatory mediators such as cytokines TNF-α, IL-1β, and IL-6 and enzymes iNOS and COX-2. Also, AM was shown to increase expression of anti-inflammatory response mediator HO-1. Presence of AM also scavenged the free radicals in vitro. In conclusion, by-products of H. discus hannai are suggested to possess notable anti-inflammatory potential which promotes the possibility of utilization as functional food ingredient.
    01/2015; 2015:1-7. DOI:10.1155/2015/526439
  • Chang‐Suk Kong · Haejin Kim · Youngwan Seo ·
    [Show abstract] [Hide abstract]
    ABSTRACT: The present study performed the bioactivity-monitored isolation of anti-adipogenic phlorotannins from Ecklonia cava as a part of the ongoing research to develop antiobesity nutraceuticals from natural origin. Extracts were partitioned into n-hexane, 85% aqueous MeOH, n-BuOH and water fractions. Their adipogenic activities were examined by measuring glycerol release level and adipogenic-related gene expression in differentiating 3T3-L1 preadipocytes. Among them, n-BuOH fractions significantly increased glycerol secretion and reduced the regulation of adipogenic transcription factors, peroxisome proliferator-activated receptor-γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), as well as tumor necrosis factor α (TNFα). Further separation from n-BuOH fraction led to the isolation of phlorotannins, triphlorethol-A, eckol and dieckol. Phlorotannins increased the glycerol secretion and reduced the glucose consumption levels of 3T3-L1 adipocytes. Moreover, the phlorotannins reduced the expression levels of PPARγ, C/EBPα and differentiation-dependent factor 1/sterol regulatory element-binding protein 1c, as well as downstream genes such as fatty acid binding protein-4, fatty acid transport protein-1, fatty acid synthase, Leptin and acyl-CoA synthetase 1. In addition, phlorotannins increased the mRNA expression of hormone-sensitive lipase while suppressing perilipin and TNFα expressions.Practical ApplicationsBrown alga, Ecklonia cava, is one of the most common edible algae in East Asian countries and widely consumed throughout Korea and Japan because of its nutritional importance along with its medicinal value. Constituents of E. cava, especially phenolic compounds, are considered to possess several bioactivities against various complications and diseases. In this regard, this study provides valuable insights concerning the antiobesity potential of E. cava and effective ingredients. Results indicate that the isolated phlorotannins act as antiobesity agents and suggest possible mechanisms of action. Following this study, a better utilization of E. cava via proper extraction of antiobesity constituents will pave the way for future nutraceuticals with antiobesity value.
    Journal of Food Biochemistry 12/2014; 39(1). DOI:10.1111/jfbc.12093 · 0.74 Impact Factor
  • Byungju Park · Seung Oh Baek · Young-Sun Song · Youngwan Seo ·

    10/2014; 29(5):343-352. DOI:10.7841/ksbbj.2014.29.5.343
  • Source
    Jung Im Lee · Chang-Suk Kong · Seung Oh Baek · Youngwan Seo ·
    [Show abstract] [Hide abstract]
    ABSTRACT: In our continuing study on the antioxidant activity of Polysiphonia stricta, its crude extract was fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions according to solvent polarity. The solvent fractions were evaluated for their potential to inhibit lipid peroxidation and reactive oxygen species (ROS) production in HT 1080 cells. The n-BuOH fraction most strongly inhibited both lipid peroxidation and ROS production in HT 1080 cells. The n-BuOH fraction was further separated by repeated silica gel column chromatography and RP-HPLC to give methyl aconitates (2 and 3). The chemical structure of isolated compounds was determinated by NMR spectral analysis. © 2014, Korea Ocean Research and Development Institute. All rights reserved.
    Ocean and Polar Research 09/2014; 36(3):247-254. DOI:10.4217/OPR.2014.36.3.247
  • Jung-Im Lee · Byung Ju Park · Hojun Kim · Youngwan Seo ·

    Bulletin- Korean Chemical Society 09/2014; 35(9):2867-2869. DOI:10.5012/bkcs.2014.35.9.2867 · 0.80 Impact Factor
  • Myoung Kuk Kwak · Da Seul Kim · Kwang-Suk Oh · Youngwan Seo ·

    08/2014; 29(4):271-277. DOI:10.7841/ksbbj.2014.29.4.271
  • Source
    You Ah Kim · Da Seul Kim · Kwang‐Suk Oh · Youngwan Seo ·
    [Show abstract] [Hide abstract]
    ABSTRACT: isolation and structure of new labdane-type diterpene (I) together with five known diterpenes
    ChemInform 05/2014; 45(18). DOI:10.1002/chin.201418206
  • [Show abstract] [Hide abstract]
    ABSTRACT: The (2'S,7'S)-O-(2-methylbutanoyl)-columbianetin (OMC) is a novel secondary metabolite extracted from Corydalis heterocarpa, which has long been used as a folk medicine for various inflammatory diseases in Korea. We examined the effect of OMC on allergic rhinitis (AR). We assessed the therapeutic effects and regulatory mechanisms of OMC on the phorbol 12-myristate 13-acetate plus A23187-stimulated mast cell line, HMC-1cells and ovalbumin (OVA)-induced AR models. OMC significantly decreased the releases of histamine and tryptase from stimulated HMC-1 cells. The degranulation process, characterized by morphological extension of the filopodia on the surface and membrane ruffling, was strongly induced in the stimulated-HMC-1 cell, however OMC suppressed the morphological changes in stimulated-HMC-1 cells. OMC reduced the production and mRNA expression of inflammatory cytokines. These inhibitory actions by OMC were dependent on the regulation of mitogen-activated protein kinases, nuclear factor-κB, and caspapase-1 signaling pathways. In the AR animal model, the increased rub scores and AR biomarkers (histamine and IgE) in ovalbumin (OVA)-sensitized mice were significantly reduced by the administration of OMC. Furthermore, eosinophils and mast cells infiltrations in nasal mucosa tissue were also blocked through the regulation of macrophage-inflammatory protein and intercellular adhesion molecule-1 levels. OMC showed the possibility to regulate AR in activated mast cells and OVA-induced AR models. Hence, we suggest that OMC is a powerful and feasible new agent to suppress AR.
    Life sciences 01/2014; 98(2). DOI:10.1016/j.lfs.2014.01.003 · 2.70 Impact Factor
  • You Ah Kim · Hojun Kim · Youngwan Seo ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Three flavonoids, luteolin (1), vitexicarpin (2) and artemetin (3), from the salt marsh plant Vitex rotundifolia, were tested for their anti-proliferative activities in AGS, MCF-7 and HT-29 human cancer cell lines and compared with the control using MTT assay. Among them, 2 was most effective with an IC50 of 6.9 and 22.8 microM against AGS and HT-29 cells, respectively. Inaddition, mRNA expression levels of major apoptosis-related genes such as p21, p53, Bcl-2 andBax in AGS cells were evaluated by reverse-transcription polymerase chain reaction (RT-PCR). Compound 2 not only enhanced most remarkably the expression level of tumor suppressor genes p53 and p21, and pro-apoptotic gene Bax at a concentration of 25 microM, but also suppressed the expression level of antiapoptotic gene Bcl-2 to 20% at the same concentration, thus shifting the Bax/Bcl-2 ratio in favor of apoptosis.
    Natural product communications 10/2013; 8(10):1405-8. · 0.91 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A bacterium CGH18 exhibiting antioxidizing and chitin-degrading activities in the colloidal chitin culture medium was isolated from salt-fermented crab. This strain was identified as Bacillus idriensis based on 16S rDNA sequence homology search. Its crude extract was partitioned between n-BuOH and . The organic layer was further partitioned between and . Antioxidant activities of crude extract and its solvent fractions were evaluated using five different bioassay methods, including the degree of occurrence of intracellular reactive oxygen species (ROS), peroxynitrite scavenging (ONOO), and oxidative damage of genomic DNA. All fractions exhibited significant antioxidant activity in bioassay systems used.
    08/2013; 28(4). DOI:10.7841/ksbbj.2013.28.4.217
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the present study, methanolic extract of Ecklonia cava and its solvent-partitioned fractions were evaluated for their antiadipogenic effect in 3T3-L1 adipocytes. One of them, n-BuOH fraction, effectively reduced lipid accumulation and glucose consumption. In addition, the presence of n-BuOH fraction in adipocytes suppressed the regulations of adipogenic transcription factors, PPARγ and SREBP1c and adipogenic specific genes, FABP4, FABP1, FAS, LPL, HSL and ACS1. Further purification of n-BuOH fractions led to the isolation of six phlorotannins (1-6). The six phlorotannins effectively suppressed triglyceride accumulation Comparative analysis showed that lipid accumulation in adipocytes was dramatically attenuated in the presence of eckstolonol (4).
    Journal of Agricultural and Food Chemistry 08/2013; 61(36). DOI:10.1021/jf401454m · 2.91 Impact Factor
  • Jung Im Lee · Myoung K Kwak · Hee Y Park · Youngwan Seo ·
    [Show abstract] [Hide abstract]
    ABSTRACT: The cytotoxicity of the brown alga Sargassum siliquastrum on human cancer cells (AGS, HT-29, HT-1080, and MCF-7) was investigated. Bioassay-guided fractionation of the crude extracts showed that the 85% aq. methanol (MeOH) fraction was the most toxic. Seven known meroterpenoids (1-7) were isolated from this cytotoxic fraction. Each compound was evaluated for its cytotoxic effect on human cancer cells. Compounds 1, 2, and 4 showed strong cytotoxicity against AGS, HT-29, and HT-1080 cell lines, with IC50 values ranging from 0.5 to 5.7 microg/mL.
    Natural product communications 04/2013; 8(4):431-2. · 0.91 Impact Factor
  • Source
    Byul-Nim Ahn · Jung-Ae Kim · Chang-Suk Kong · Youngwan Seo · Se-Kwon Kim ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Ultraviolet-B (UVB) irradiation acts primarily on the epidermal basal cell layer of the skin, inducing harmful biological effects. In this study, we have investigated the effect of libanoridin isolated from Corydalis heterocarpa against UVB-induced damage in human keratinocyte (HaCaT) cells and the molecular mechanism underlying those effects. Treatment with libanoridin inhibited the cell cytotoxicity and LDH induced by UVB exposure at 40 mJ/cm2. Additionally, expression levels of type IV collagenases (MMP-2, MMP-9) were decreased by libanoridin. Furthermore, MMP tissue inhibitors were enhanced followed by treatment with libanoridin. Moreover, UVB-induced activation of phosphorylation of three MAPKs such as JNK, ERK, p38 and AP-1 transcription factor were decreased by treatment with libanoridin. Our present study demonstrates that libanoridin has the abilities to inhibit UVB-induced cellular damage via ASK1-MAPK and AP-1 signalling pathways. Therefore, libanoridin may be used as an effective natural compound to prevent skin damage due to UVB exposure.
    Experimental Dermatology 02/2013; 22(2):155-7. DOI:10.1111/exd.12085 · 3.76 Impact Factor

  • Ocean and Polar Research 12/2012; 34(4):385-394. DOI:10.4217/OPR.2012.34.4.385
  • Chang-Suk Kong · Youngwan Seo ·
    [Show abstract] [Hide abstract]
    ABSTRACT: In the present study, effect of flavonoid glucopyranoside, isorhamnetin 3-О-β-D-glucopyranoside, from Salicornia herbacea on adipogenic differentiation were evaluated in 3T3-L1 adipocytes. Confluent 3T3-L1 preadipocytes in medium (0.5 mM methylisobutylxanthine, 0.25 µM dexamethasone, 5 µg/mL insulin, and 10% fetal bovine serum [FBS]) were differentiated into adipocytes for 6 days with/without isorhamnetin 3-О-β-D-glucopyranoside. The presence of isorhamnetin 3-О-β-D-glucopyranoside effectively suppressed adipogenic differentiation by downregulation of peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer-binding proteins (C/EBPα), sterol regulatory element-binding protein 1 (SREBP1), and the adipocyte-specific proteins. Moreover, the specific mechanism mediating the effects of isorhamnetin 3-О-β-D-glucopyranoside was confirmed by activation of AMP-activated protein kinase (AMPK). These findings suggest that isorhamnetin 3-О-β-D-glucopyranoside exerts antiadipogenic activity through AMPK activation. This study should find the nutraceutical value of S. herbacea-derived glucopyranoside, isorhamnetin 3-О-β-D-glucopyranoside, as potent candidate of antiobesity agent via alleviation of lipid accumulation.
    Immunopharmacology and Immunotoxicology 09/2012; 34(6). DOI:10.3109/08923973.2012.670643 · 1.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the present study, the bioactivity-monitored isolation of flavonoid glucopyranosides from the salt-marsh plant Salicornia herbacea was performed, and their effects on adipogenic differentiation were evaluated in 3T3-L1 adipocytes. Among the solvent-partitioned fractions from S. herbacea, the 85% aq. MeOH and n-BuOH fractions effectively reduced the levels of triglyceride accumulation, glucose consumption and adipogenic transcription factor peroxisome proliferator-activated receptor-γ (PPARγ) expression. Further purification of the n-BuOH fraction led to the isolation of two flavonoid glucopyranosides, isorhamnetin 3-O-β-d-glucopyranoside (A) and quercetin 3-O-β-d-glucopyranoside (B), as the active principles. The presence of glucopyranosides A and B in adipocyte cells effectively suppressed adipogenic differentiation. Comparative analysis indicated that adipogenic differentiation was dramatically attenuated in the presence of glucopyranoside B rather than glucopyranoside A. The anti-adipogenic activity of glucopyranosides B was confirmed by down-regulation of sterol regulatory element-binding protein 1 (SREBP1), CCAAT/enhancer-binding proteins (C/EBPα), PPARγ and the adipocyte-specific proteins. Moreover, the specific mechanism mediating the effects of glucopyranosides B was confirmed by activation of AMP-activated protein kinase (AMPK). Findings from this study should underscore the nutraceutical value of S. herbacea-derived glucopyranosides as potent anti-obesity agents via alleviation of lipid accumulation.
    PROCESS BIOCHEMISTRY 07/2012; 47(7):1073–1078. DOI:10.1016/j.procbio.2012.03.011 · 2.52 Impact Factor

Publication Stats

1k Citations
161.11 Total Impact Points


  • 2003-2015
    • Korea Maritime and Ocean University
      • Division of Marine Environment and Bioscience
      Busan, Busan, South Korea
  • 2001
    • Hannam University
      South Korea
  • 1998
    • Korea Institute of Science and Technology
      Sŏul, Seoul, South Korea