Joongku Lee

Dongguk University, Sŏul, Seoul, South Korea

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Publications (19)35.82 Total impact

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    ABSTRACT: Larrea nitida is a plant that belongs to the Zygophyllaceae family and is widely used in South America to treat inflammatory diseases, tumors and menstrual pain. However, its pharmacological activity remains unclear. In this study we evaluated the property of selective estrogen receptor modulator (SERM) of Larrea nitida extracts (LNE) as a phytoestrogen that can mimic, modulate or disrupt the actions of endogenous estrogens, depending on the tissue and relative amount of other SERMs. To investigate the property of SERM of LNE, we performed MCF-7 cell proliferation assays, estrogen response element (ERE)-luciferase reporter gene assay, human estrogen receptor (hER) binding assays and in vivo uterotrophic assay. To gain insight into the active principles, we performed a bioassay-guided analysis of LNE employing solvents of various polarities and using classical column chromatography, which yielded 16 fractions (LNs). LNE showed high binding affinities for hERα and hERβ with IC50 values of 1.20 ×10(-7) g/ml and 1.00×10(-7) g/ml, respectively. LNE induced 17β-estradiol (E2)-induced MCF-7 cell proliferation, however, it reduced the proliferation in the presence of E2. Furthermore, LNE had an atrophic effect in the uterus of immature rats through reducing the expression level of progesterone receptor (PR) proteins. LN08 and LN10 had more potent affinities for binding on hER α and β than other fractions. Our results indicate that LNE had higher binding affinities for hERβ than hERα, and showed SERM properties in MCF-7 breast cancer cells and the rat uterus. LNE may be useful for the treatment of estrogen-related conditions, such as female cancers and menopause.
    Biomolecules & therapeutics. 07/2014; 22(4):347-54.
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    Journal of Ethnopharmacology 04/2008; 117(1):180-180. · 2.94 Impact Factor
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    ABSTRACT: Seven flavonoids (1-7), two triterpenoids (8 and 9) and four steroids (10, 11, 12 and 13) were isolated from the whole plant of Tiarella polyphylla. Based on the physicochemical and spectroscopic analyses, their structures were identified as myricetin (1), astragalin (2), afzelin (3), quercitrin (4), myricitin (5), nicotiflorin (6), isoquercitrin (7), tiarellic acid (8), 3beta-hydroxy-20(29)lupen-27-oic acid (9), beta-sitosterol-3-O-beta-D-glucoside (10), stigmasterol-3-O-beta-D-glucoside (11), beta-sitosterol (12) and ergosterol endoperoxide (13). All 13 compounds, with the exception of tiarellic acid were isolated for the first time from T. polyphylla. In the anti-complementary assay, the steroids (12 and 13) exhibited potent activities; whereas, the flavonoids (1 to 7) showed weak or no activities, but even the triterpenoids (8 and 9) and steroidal saponins (10 and 11) evoked hemolysis.
    Archives of Pharmacal Research 02/2008; 31(1):10-6. · 1.54 Impact Factor
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    Journal of Ethnopharmacology - J ETHNOPHARMACOL. 01/2008; 117(1):181-181.
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    Journal of Ethnopharmacology - J ETHNOPHARMACOL. 01/2008; 117(1):182-182.
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    ABSTRACT: A new coumarin, hydroxylomatin (1), was isolated from the CHCl(3)-soluble fraction of the roots of Angelica purpuraefolia, along with one ferulate (2) and three other known coumarins (3-5) including khellactone (3). The structure of hydroxylomatin (1) was determined to be 3'beta,5'-dihydroxy-3',4'-dihydroseselin (1) by spectroscopic means including 2D-NMR. The modified Mosher's method was used to determine the chiral center at C-1 of compound 2. Khellactone (3) is a major compound of the roots of A. purpuraefolia. This study also examined the antitumor activity of khellactone (3) using a LLC mouse lung carcinoma in the BDF-1 mice and a NCI-H460 human lung carcinoma in a human tumor xenograft model in nude mice. This compound (3) inhibited LLC tumor growth with a T/C (mean value of treated group/mean value of control group) value of 12.9% at a dose of 5 mg/kg and 33.2% at a dose of 10 mg/kg, respectively, in a dose-dependent manner. In addition, it suppressed the growth of NCI-H460 tumor cells, accounting for 81.4% at a dose of 10 mg/kg in nude mice.
    Phytotherapy Research 06/2007; 21(5):406-9. · 2.40 Impact Factor
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    ABSTRACT: Species of the Viola genus, used in traditional medicines for the treatment of parasites, were collected and petroleum ether extract was obtained by sonication. The antiplasmodial activity of petroleum ether extracts was evaluated in vitro against the chloroquine-resistant FcB1 strain of Plasmodium falciparum. Bioactivity-guided fractionation of the petroleum ether extracts of the whole plants of Viola verecunda has led to the isolation of epi-oleanolic acid, a triterpenoid, displaying high antiplasmodial activity (IC(50) 0.18 mug/ml). This is the first report of the isolation and antiplasmodial activity of epi-oleanolic acid from this species.
    Parasitology Research 03/2007; 100(3):641-4. · 2.85 Impact Factor
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    ABSTRACT: Aldose reductase (AR), the key enzyme of the polyol pathway, is known to play important roles in the diabetic complication. The inhibitors of AR, therefore, would be potential agents for the prevention of diabetic complication. The AR inhibition activity of several isoflavonoids was evaluated in vitro against rat lens. Tectoridin-4'-O-beta-D-glucoside exhibited strong AR inhibition activity on rat lens with an IC50 of 0.54 microM. Similar activities were recorded for the natural tectorigenin and tectoridin. In contrast, tectoridin-4'-O-beta-D-glucoside showed a stronger inhibitory activity than tectorigenin and tectoridin. Our results indicate that glucose conjugation position in this type of isoflavonoids may be required for the activity.
    Bioorganic & Medicinal Chemistry 12/2006; 14(22):7592-4. · 2.90 Impact Factor
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    ABSTRACT: Allergic inflammation of the airways has a critical role in asthma development. We investigated a suppressive effect of verproside (3,4-dihydroxy catalpol) isolated from the extract of Pseudolysimachion longifolium on asthmatic parameters--such as immunoglobulin E (IgE) level, cytokine release, eosinophilia, airway hyperresponsiveness and mucus hypersecretion--in an OVA-sensitized/challenged mouse model. Verproside significantly inhibited the increase of total IgE and the cytokines IL-4 and IL-13 in plasma and bronchoalveolar lavage fluid, and also effectively suppressed airway hyperresponsiveness, eosinophilia and mucus hypersecretion in OVA-induced asthmatic mice. The efficacy of verproside was comparable to montelukast, an anti-asthmatic drug that is currently available. These results suggest that verproside could be a major marker in herbal medicines that are used for asthma treatment, and could also act as a lead for anti-asthmatic drugs.
    International Immunopharmacology 07/2006; 6(6):978-86. · 2.42 Impact Factor
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    ABSTRACT: Matrix metalloproteinases (MMPs) are a family of enzymes whose main function is degradation of the extracellular matrix. Matrix metalloproteinase-1 (MMP-1) degrades type I procollagen constituting the major structural component of the basement membrane and extra cellular membrane. The enzymatic activity is found to be elevated in photoaging. With the aim of finding novel MMP-1 inhibitors from natural products, 15 extracts of the Viola taxa, which are used as prescriptions for skin eruption treatment in traditional medicine, were screened for their inhibitory activities towards MMP-1. Among the 15 tested materials, the methanol extracts of Viola hondoensis W. BECKER et H. BOISS, Viola ibukiana MAKINO, Viola lactiflora NAKAI and Viola verecunda A. GRAY were potential inhibitory to MMP-1, and other Viola taxa showed a weak inhibitory effect at a concentration of 100 microg/ml. We investigated the effect of MMP-1 inhibitory of the solvent fractions of the same plants (Viola hondoensis, Viola ibukiana and Viola verecunda). Therefore, a strong inhibition was found in the ethylacetate fractions of Viola verecunda with inhibitory activity (>90%) at a concentration of 10 microg/ml. Here we investigated the effect of sativan isolated from the ethylacetate fractions of Viola verecunda on the expression of MMPs in UV-irradiated human skin fibroblasts in vitro. Sativan markedly reduced UV-induced MMP-1 expression at the protein levels in a dose-dependent manner. Our report is the first description for the ability of sativan to regulate UV-induced MMP-1 expression.
    Journal of Ethnopharmacology 03/2006; 104(1-2):12-7. · 2.94 Impact Factor
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    ABSTRACT: Long-term and repeated exposure of ultraviolet (UV) light, a harmful environmental stress, on the skin often induces chronic skin diseases, such as skin cancer as well as photo-aging (premature skin aging), and the mechanisms of these skin damages are closely associated with up-regulation of matrix metalloproteinases (MMPs) activities. Here, we investigated the effect of quercetin-3-O-beta-d-(6''-feruloyl)-galactopyranoside isolated from the stems of Viola hondoensis (Violaceae) on the expression of MMPs in UV-irradiated human skin fibroblasts in vitro. Quercetin-3-O-beta-d-(6''-feruloyl)-galactopyranoside markedly reduced UV-induced MMP-1 expression at the protein levels in a dose-dependent manner. Our report is the first description for the ability of quercetin-3-O-beta-d-(6''-feruloyl)-galactopyranoside to regulate UV-induced MMP-1 expression.
    Journal of Ethnopharmacology 11/2005; 101(1-3):176-9. · 2.94 Impact Factor
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    ABSTRACT: The EtOAc-soluble fraction from a methanolic extract of Hovenia dulcis Thunb. exhibited neuroprotective activity against glutamate-induced neurotoxicity in mouse hippocampal HT22 cells. The neuroprotective activity-guided isolation resulted in 8 phenolic compounds (1-8), such as vanillic acid (1), ferulic acid (2), 3,5-dihydroxystilbene (3), (+)-aromadendrin (4), methyl vanillate (5), (-)-catechin (6), 2,3,4-trihydrobenzoic acid (7), and (+)-afzelechin (8). Among these, compounds 6 and 8 had a neuroprotective effect on the glutamate-induced neurotoxicity in HT22 cells. Furthermore, compound 6 had a DPPH free radical scavenging effect with an IC50 value of 57.7 microM, and a superoxide anion radical scavenging effect with an IC50 value of 8.0 microM. Both compounds 6 and 8 had ABTS cation radical scavenging effects with IC50 values of 7.8 microM and 23.7 microM, respectively. These results suggest that compounds 6 and 8 could be neuroprotectants owing to their free radical scavenging activities.
    Archives of Pharmacal Research 08/2005; 28(7):804-9. · 1.54 Impact Factor
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    ABSTRACT: Isolation of the ethyl acetate soluble fraction from aerial parts of Viola hondoensis W. BECKER et H. BOISSIEU yielded one major isoflavonoid glycoside, tectoridin-4'-O-beta-D-glucoside. The structure of the compound was certainly determined by chemical analyses, as well as 1D- and 2D-NMR spectroscopy. The compound exhibited potent inhibitory activity against the expression of matrix metalloproteinase-1 caused by UV-irradiation in cultured human skin fibroblasts.
    Biological & Pharmaceutical Bulletin 07/2005; 28(6):1123-5. · 1.85 Impact Factor
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    ABSTRACT: Long term and repeated exposure of ultraviolet (UV) light, a harmful environmental stress, on the skin often induces chronic skin diseases such as skin cancer as well as photoaging (premature skin aging), and the mechanisms of these skin damages are closely associated with up-regulation of matrix metalloproteinases (MMPs) activities. Here we investigated the effect of 2',4',7-trihydroxyisoflavone isolated from the whole plants of Viola hondoensis (Violaceae) on the expression of MMPs in UV-irradiated human skin fibroblasts in vitro. 2',4',7-Trihydroxyisoflavone markedly reduced UV-induced MMP-1 expression, but not MMP-2, at the both mRNA and protein levels in a dose-dependent manner. Our report is the first description for the ability of 2',4',7-trihydroxyisoflavone to regulate MMP-1 expression specifically.
    Biological & Pharmaceutical Bulletin 06/2005; 28(5):925-8. · 1.85 Impact Factor
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    ABSTRACT: Long term and repeated exposure of ultraviolet (UV) light, a harmful environmental stress, on the skin often induces chronic skin diseases such as skin cancer as well as photoaging (premature skin aging), and the mechanisms of these skin damages are closely associated with up-regulation of matrix metalloproteinases (MMPs) activities. Here we investigated the effect of tiarellic acid on the expressions of MMP-1 and type 1 procollagen in ultraviolet irradiation of cultured human skin fibroblasts. Tiarellic acid reduced the expression of MMP-1 and induced the expression of type 1- procollagen at the protein levels in a dose-dependent manner by ultraviolet irradiation. Taken together, our results suggest that tiarellic acid plays an important role in the reduction of MMP-1 and induction of type 1- procollagen by ultraviolet irradiation.
    Journal of Ethnopharmacology 05/2005; 98(1-2):185-9. · 2.94 Impact Factor
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    ABSTRACT: Four flavonoids, epicatechin (1), afzelin (2), quercitrin (3), and tiliroside (4), were isolated from the leaves of Litsea japonica (Thunb.) Jussieu (Lauraceae). The structures of compounds were identified by comparing their chemical and spectral data with those previously reported. The flavonoids (1-4) were tested for their anti-complement activity against classical pathway of complement system. Compounds 2-4 showed inhibitory activity against complement system with IC50 values of 258, 440, and 101 microm, respectively, whereas 1 was inactive. For the evaluation of the structure-activity relationship of 5,7-dihydroxyflavones, myricitrin (5) from Juglans mandshurica also tested for it's anti-complement activity and is inactive in this assay system. Furthermore, compounds 2, 3, and 5 were hydrolyzed with naringinase to give kaempferol (2a), quercetin (3a), and myricetin (5a), and these were also tested for their activity. Of the three aglycones, 2a exhibited anti-complement activity with an IC50 value of 730 microM, while 3a and 5a were inactive. The inhibitory potencies of 2, 2a, 3, 3a, 5, and 5a against complement activity increased in inverse proportion to number of free hydroxyls on B-ring of 5,7-dihydroxyflavone. Of the compounds tested, 4 showed the most potent inhibitory activity against the complement system.
    Phytotherapy Research 05/2005; 19(4):273-6. · 2.40 Impact Factor
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    ABSTRACT: A new norlignan, styraxlignolide A (1), and two new terpenes, styraxosides A (2) and B (3), were isolated from the MeOH-soluble fraction of Styrax japonica Sieb. et Zucc. (Styracaceae) stem bark, together with two known compounds, egonol (4) and masutakeside I (5). The new compounds were determined as 5-(3''-hydroxypropyl)-7-methoxy-2-(3',4'-dimethoxyphenyl)-benzofuran 3''- O-[beta-D-xylopyranoside-(1-->6)-beta- D-glucopyranoside] (1), 3beta,7beta-dihydroxy-4alpha,4beta,8beta,10beta,14alpha-pentamethyl-5alpha-gon-16-en-2-one 3-O-[beta-D-glucopyranoside-(1-->2)-beta-D-glucopyranoside] (2), and 3beta,17beta-dihydroxy-28-norolean-12-en-16-one 3-O-[alpha-L-rhamopyranoside-(1-->2)-beta-D-glucuronopyranoside] (3) by spectroscopic means including 2D-NMR. The five compounds were tested in vitro for anti-complement activity against the complement system. Compounds 1, 3, 4, and 5 displayed inhibitory activity in the anti-complement assay, with IC50 values of 123, 65, 33, and 166 microM, respectively. Compound 1a and camellenodiol (3a), obtained from acid hydrolysis of 1 and 3, respectively, did not affect the hemolytic activity of human serum against sensitized erythrocytes. This shows that a sugar seems to play a role of enhancing significantly anti-complement activity.
    Planta Medica 12/2004; 70(12):1210-5. · 2.35 Impact Factor
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    ABSTRACT: Although many studies have been performed to elucidate the molecular consequences of ultraviolet irradiation, little is known about the effect of natural products. Ultraviolet irradiation is widely considered to be an environmental stress. Here we investigated the effect of 3,23-dihydroxy-20(29)-lupen-27-oic acid on the regulation of MMP-1 and type 1 procollagen in Ultraviolet irradiation of cultured old age human dermal fibroblasts. 3, 23-dihydroxy-20(29)-lupen-27-oic acid was isolated from Tiarella polyphylla D. Don (Saxifragaceae). Among them, 3, 23-dihydroxy-20(29)-lupen-27-oic acid induced the regulation of Type 1- procollagen and reduced the regulation of MMP-1 at the protein levels in a dose-dependent manner by ultraviolet irradiation. Taken together, our results suggest that 3, 23-dihydroxy-20(29)-lupen-27-oic acid plays an important role in the induction of Type 1-procollagen and reduction of MMP-1 by ultraviolet irradiation in old age human dermal fibroblasts.
    Archives of Pharmacal Research 11/2004; 27(10):1060-4. · 1.54 Impact Factor
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    ABSTRACT: The anticomplement activity-guided fractionation of the methanol extract of Euphorbia kansui L. resulted in isolation of three diterpenes, two triterpenes, and two sterols (1–7) from ethyl acetate fraction. By spectroscopic analysis, their chemical structures were elucidated as: β-amyrin (1); kansuiphorin C (2); 3-O-(2′E,4′Z-decadienoyl)-ingenol (3); 3-O-(2,3-dimethylbutyryl)-13-O-n-dodecanoyl-13-hydroxyingenol (4); β-sitosterol (5); α-euphol (6); β-sitosterol-3-O-β-D-glucopyranoside (7). These compounds were investigated Pitin vitro for their anticomplement activity against the classical pathway of the complement system, with compounds 2–4 exhibiting significant anticomplement activity with respective 50% inhibitory concentration values of 44.1±3.8, 89.5±5.5, and 152.1±6.2 μM.
    Journal of the Korean Society for Applied Biological Chemistry 54(2). · 0.43 Impact Factor

Publication Stats

123 Citations
35.82 Total Impact Points

Institutions

  • 2014
    • Dongguk University
      • College of the Pharmacy
      Sŏul, Seoul, South Korea
  • 2008
    • Yanbian University
      Yang-chi-t'eng, Jilin Sheng, China
  • 2004–2008
    • Korea Research Institute of Bioscience and Biotechnology KRIBB
      • • Immunomodulator Research Laboratory
      • • Laboratory of Immunomodulator
      Anzan, Gyeonggi Province, South Korea
  • 2006–2007
    • University of Mississippi
      • National Center for Natural Products Research
      Oxford, MS, United States
  • 2004–2006
    • Seoul National University
      • Department of Dermatology
      Seoul, Seoul, South Korea
  • 2005
    • Seoul National University Hospital
      • Department of Dermatology
      Seoul, Seoul, South Korea