Kyoung Hwangbo

Yeungnam University, Onyang, South Chungcheong, South Korea

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Publications (9)18.61 Total impact

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    ABSTRACT: Cellular senescence is known to contribute to tissue aging, a variety of age-related diseases, tissue regeneration, and cancer. Therefore, aging intervention might be useful for prevention of aging as well as age-related disease. In this study, we investigated compounds from Polygonum aviculare to determine if they inhibited cellular senescence in human primary cells, human dermal fibroblasts (HDFs) and human umbilical vein endothelial cells (HUVECs). Ten compounds from P. aviculare were purified and their inhibitory effects on adriamycin-induced cellular senescence were measured by observing senescence-associated β-galactosidase (SA-β-gal) activity and reactive oxygen species. Among them, compound 9 (quercetin-3-O-β-D-glucuronide) showed inhibitory effects against cellular senescence in HDFs and HUVECs treated with adriamycin. Additionally, compound 9 rescued replicative senescence in HDFs and HUVECs. These data imply that compound 9 represses cellular senescence in human primary cells and might be useful for the development of dietary supplements or cosmetics that ameliorate tissue aging or aging-associated diseases.
    Archives of Pharmacal Research 03/2014; · 1.54 Impact Factor
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    ABSTRACT: Cellular senescence contributes to tissue and organismal aging, tumor suppression and progress, tissue repair and regeneration, and age-related diseases. Thus, aging intervention might be a promising target for treatment and prevention of diverse age-related diseases. In the present study, we investigated whether juglanin purified from the crude extract of Polygonum aviculare exerted inhibitory activity against cellular senescence in human dermal fibroblasts (HDFs). Juglanin decreased senescence-associated β-galactosidase activity (SA-β-gal) and the level of reactive oxygen species in senescent cells induced by adriamycin treatment. Juglanin also repressed SA-β-gal activity in HDFs under replicative senescence. These results suggest that juglanin represses cellular senescence in HDFs and might be useful for the development of dietary supplements or cosmetics that alleviate tissue aging or age-related diseases.
    Journal of Natural Medicines 02/2014; · 1.52 Impact Factor
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    ABSTRACT: A rapid and simple high-performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was developed for the determination of betaine from Lycii Fructus. Betaine was separated with an Atlantis hydrophilic interaction liquid chromatography silica column (4.6 × 150 mm, 5 μm, 100 Å) by isocratic elution using 30 mM ammonium acetate buffer and acetonitrile (20:80, v/v %) as the mobile phase. The flow rate was 1.0 mL/min, and the temperature for the spray chamber and drift tube was set at 30 and 50 °C, respectively. The method was fully validated with respect to linearity, precision, accuracy, stability and robustness. The HPLC/ELSD method was applied successfully to the quantification of betaine in the extract of Lycii Fructus. The HPLC analytical method for pattern recognition analysis was validated by repeated analysis of twenty-six L. barbarum L. from China (BC01-BC26), 3 L. barbarum L. (BJ27-BJ29) from Japan, 12 L. chinense Miller from China (CC30-CC41) and 51 L. chinense Miller samples (CK42-CK92) from Korea. The results indicate that the established HPLC/ELSD method is suitable for quality evaluation of Lycii Fructus.
    Archives of Pharmacal Research 05/2013; · 1.54 Impact Factor
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    ABSTRACT: Three anthraquinones (1, 2 and 4), three stilbenes (5, 6 and 7) and 3,5-dihydroxybenzyl alcohol (3) were isolated from Reynoutria japonica. Their structures were identified as emodin (1), emodin-8-O-β-D-glucoside (2), 3,5-dihydroxybenzyl alcohol (3), citreorosein (4), cis-resveratrol (5), trans-resveratrol (6) and trans-resveratrol-5-O-β-D-glucopyranoside (7) by comparing their physicochemical and spectral data with published data. Compound 3 was isolated for the first time from the Polygonaceae family. Among the purified compounds, 3 showed more potent inhibitory activity against topoisomerase I (IC(50): 4 μM) than camptothecin, as the positive control (IC(50): 18 μM). Compounds 3, 4, 5, 6 and 7 showed stronger inhibitory activities toward DNA topoisomerase II (IC(50): 0.54, 14, 15, 0.77 and 3 μM, respectively) than the positive control, etoposide (IC(50): 44 μM). Compounds 1 and 4 displayed weak cytotoxicities against human lung cancer (A549), ovarian cancer (SK-OV-3), human liver hepatoblastoma (HepG2) and colon adenocarcinoma (HT-29) cell lines.
    Archives of Pharmacal Research 09/2012; 35(9):1583-9. · 1.54 Impact Factor
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    ABSTRACT: Citreorosein (CIT), an anthraquinone component of Polygoni cuspidati (P. cuspidati) radix, suppressed gene expression of proinflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β in mouse bone marrow-derived mast cells (BMMCs) stimulated with phorbol 12-myristate 13-acetate (PMA) plus the calcium ionophore A23187. To investigate the molecular mechanisms underlying CIT inhibition of the pro-inflammatory cytokine production, its effects on the activation of both nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) were assessed. CIT attenuated phosphorylation of the MAPKs including extracellular signal-regulated kinase 1/2 (ERK1/2), p38 MAP kinase and c-Jun NH(2)-terminal kinase (JNK). Furthermore, CIT strongly inhibited DNA binding activity of NF-κB through the inhibition of phosphorylation and degradation of inhibitor of kappaB (IκB) as well as activator protein-1 (AP)-1 through the reduction of phosphorylation of c-Jun. These results demonstrate that CIT inhibits proinflammatory cytokines production through the inhibition of both MAPKs and AKT-mediated IκB kinase (IKK) phosphorylation and subsequent inhibition of transcription factor NF-κB activation, thereby attenuating the production of proinflammatory cytokines.
    Biological & Pharmaceutical Bulletin 01/2012; 35(6):938-45. · 1.85 Impact Factor
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    ABSTRACT: In this study, we examined the effects of citreorosein (CIT), an anthraquinone component of Polygoni cuspidati radix (P. cuspidati, Polygonaceae), on cyclooxygenase (COX)-2 dependent prostaglandin (PG)D2 generation in mast cells, central effector cells of allergy and other inflammatory diseases. CIT strongly inhibited COX-2-dependent PGD2 generation in a concentration-dependent manner in mouse bone marrow-derived mast cells (BMMCs) stimulated with stem cell factor (SCF)/IL-10/LPS. In an effort to identify the mechanisms underlying the inhibition of COX-2-dependent PGD2 generation by CIT, we examined the effects of this compound on MAP kinases, Akt and NF-κB signaling pathways, which are essential for COX-2 induction. CIT inhibited nuclear translocation of the nuclear factor (NF)-κB p65 subunit and its cognate DNA-binding activity, which correlated with its inhibitory effects on the phosphorylation of Akt and IKK and subsequent phosphorylation and degradation of IκB. Furthermore, CIT significantly attenuated the DNA binding of activator protein (AP)-1 that regulates COX-2 expression through the reduction of the phosphorylation of c-Jun. Moreover, inhibition of PGD2 generation by CIT was accompanied by a decrease in phosphorylation of cytosolic phospholipase A2α. Taken together, the present study suggests that CIT represents a potential therapeutic approach for the treatment of inflammatory diseases.
    Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 12/2011; 50(3-4):913-9. · 2.99 Impact Factor
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    ABSTRACT: The high-affinity receptor for IgE (FcɛRI)-mediated activation of mast cells plays an important role in allergic diseases such as asthma, allergic rhinitis and atopic dermatitis. Emodin, a naturally occurring anthraquinone derivative in oriental herbal medicines, has several beneficial pharmacologic effects, such as anti-cancer and anti-diabetic activities. However, the anti-allergic effect of emodin has not yet been investigated. To assess the anti-allergic activity of emodin, in vivo passive anaphylaxis animal model and in vitro mouse bone marrow-derived mast cells were used to investigate the mechanism of its action on mast cells. Our results showed that emodin inhibited degranulation, generation of eicosanoids (prostaglandin D(2) and leukotriene C(4)), and secretion of cytokines (TNF-α and IL-6) in a dose-dependent manner in IgE/Ag-stimulated mast cells. Biochemical analysis of the FcɛRI-mediated signaling pathways demonstrated that emodin inhibited the phosphorylation of Syk and multiple downstream signaling processes including mobilization of intracellular Ca(2+) and activation of the mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and NF-κB pathways. When administered orally, emodin attenuated the mast cell-dependent passive anaphylactic reaction in IgE-sensitized mice. Thus, emodin inhibits mast cell activation and thereby the anaphylactic reaction through suppression of the receptor-proximal Syk-dependent signaling pathways. Therefore, emodin might provide a basis for development of a novel anti-allergic drug.
    Biochemical pharmacology 09/2011; 82(11):1700-8. · 4.25 Impact Factor
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    ABSTRACT: In this study, manassantin A (Man A), an herbal medicine isolated from Saururus chinensis (S. chinensis), markedly inhibited 5-lipoxygenase (5-LO)-dependent leukotriene C(4) (LTC(4)) generation in bone marrow-derived mast cells (BMMCs) in a concentration-dependent manner. To investigate the molecular mechanisms underlying the inhibition of LTC(4) generation by Man A, we assessed the effects of Man A on phosphorylation of cytosolic phospholipase A(2) (cPLA(2)) and mitogen-activated protein kinases (MAPKs). Inhibition of LTC(4) generation by Man A was accompanied by a decrease in cPLA(2) phosphorylation, which occurred via the MAPKs including extracellular signal-regulated protein kinase-1/2 (ERK1/2) as well as p38 and c-Jun N-terminal kinase (JNK) pathways. Taken together, the present study suggests the Man A represents a potential therapeutic approach for the treatment of airway allergic-inflammatory diseases.
    Biological & Pharmaceutical Bulletin 01/2011; 34(11):1769-72. · 1.85 Impact Factor
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    ABSTRACT: Twenty five compounds including ten triterpenes (1-3, 5-11), six flavonoids (12-15, 24, 25), five lignans (17, 18, 21-23), two butenyl clohexnone glycosides (19-20), one fructofuranoside (16) and one fatty acid (4) were isolated from the roots of Ulmus davidiana var. japonica. The structures of those compounds were identified by comparing their physicochemical and spectral data with those of published in literatures. All the compounds were evaluated for DNA topoisomerase inhibitory activities and cytotoxicities. Among the purified compounds, 4 and 19 showed more potent inhibitory acitivities (IC(50): 39 and 19 μM, respectively) than camptothecin, as the positive control (IC(50): 46 μM) against topoisomerase I. Compounds, 4, 10, 12, 19, 24 and 25 showed strong inhibitory activities toward DNA topoisomerase II (IC(50): 0.1, 0.52, 0.47, 0.42, 0.17 μM and 17 nM, respectively), which were more potent than that of etoposide as positive control (IC(50): 20 μM). In A549 cell line, 5 and 6 showed cytotoxicities (IC(50): 4 μM and 3 μM, respectively, with IC(50) of camptothecin as positive control: 10.3 μM). In the HepG2 cell line, 3, 5 and 7 showed cytotoxicity (IC(50): 4, 3 and 4 μM, respectively, with IC(50) of camptothecin: 0.3 μM). Compounds 6, 12 and 23 showed cytotoxicities in the HT-29 cell line (IC(50): 19, 19 and 15 μM, respectively, with IC(50) of camptothecin: 2 μM).
    Archives of Pharmacal Research 09/2010; 33(9):1307-15. · 1.54 Impact Factor