Entity

Time filter

Source Type


Lee H.-A.,Kyungpook National University | Song M.-J.,Kyungpook National University | Seok Y.-M.,Kyungpook National University | Seok Y.-M.,Korea Promotion Institute for Traditional Medicine Industry | And 4 more authors.
PLoS ONE | Year: 2015

Histone deacetylases (HDACs) act as corepressors in gene transcription by altering the acetylation of histones, resulting in epigenetic gene silencing. We previously reported that HDAC3 acts as a coactivator of the mineralocorticoid receptor (MR). Although HDAC3 forms complexes with class II HDACs, their potential role in the transcriptional activity of MR is unclear. We hypothesized that HDAC4 of the class II family stimulates the transcriptional activity of MR. The expression of MR target genes was measured by quantitative real-time PCR. MR and RNA polymerase II recruitment to promoters of MR target genes was analyzed by chromatin immunoprecipitation. The association of MR with HDACs was investigated by co-immunoprecipitation. MR acetylation was determined with an anti-acetyl-lysine antibody after immunoprecipitation with an anti-MR antibody. Among the class II HDACs, HDAC4 interacted with both MR and HDAC3 after aldosterone stimulation. The nuclear translocation of HDAC4 was mediated by protein kinase A (PKA) and protein phosphatases (PP). The transcriptional activity of MR was significantly decreased by inhibitors of PKA (H89), PP1/2 (calyculin A), class I HDACs (MS-275), but not class II HDACs (MC1568). MR acetylation was increased by H89, calyculin A, and MS-275, but not by MC1568. Interaction between MR and HDAC3 was significantly decreased by H89, calyculin A, and HDAC4 siRNA. A non-genomic effect of MR via PKA and PP1/2 induced nuclear translocation of HDAC4 to facilitate the interaction between MR and HDAC3. Thus, we have uncovered a crucial role for a class II HDAC in the activation of MR-dependent transcription. Copyright: © 2015 Lee et al. Source


Nagajyothi P.C.,Dongguk University | Cha S.J.,Daegu Haany University | Yang I.J.,Dongguk University | Sreekanth T.V.M.,Catholic University of Daegu | And 3 more authors.
Journal of Photochemistry and Photobiology B: Biology | Year: 2015

The exploitation of various plant materials for the green synthesis of nanoparticles is considered an eco-friendly technology because it does not involve toxic chemicals. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized using the root extract of Polygala tenuifolia. Synthesized ZnO NPs were characterized by UV-Vis spectroscopy, FTIR, TGA, TEM, SEM and EDX. Anti-inflammatory activity was investigated in LPS-stimulated RAW 264.7 macrophages, whereas antioxidant activity was examined using a DPPH free radical assay. ZnO NPs demonstrated moderate antioxidant activity by scavenging 45.47% DPPH at 1 mg/mL and revealed excellent anti-inflammatory activity by dose-dependently suppressing both mRNA and protein expressions of iNOS, COX-2, IL-1β, IL-6 and TNF-α. © 2015 Elsevier B.V. All rights reserved. Source


Kim H.-H.,Kyungpook National University | Kim H.-H.,Korea Promotion Institute for Traditional Medicine Industry | Bae Y.,Kyungpook National University | Kim S.-H.,Kyungpook National University
Food and Chemical Toxicology | Year: 2013

A great number of people are suffering from allergic inflammatory disease such as asthma, atopic dermatitis, and sinusitis. Therefore discovery of drugs for the treatment of these diseases is an important subject in human health. In this study, we investigated anti-allergic inflammatory effect of galangin and underlying mechanisms of action using in vitro and in vivo models. Galangin inhibited histamine release by the reduction of intracellular calcium in phorbol 12-mystate 13-acetate plus calcium ionophore A23187-stimulated human mast cells (HMC-1). Galangin decreased expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-8. The inhibitory effect of galangin on theses pro-inflammatory cytokines was related with c-Jun N-terminal kinases, and p38 mitogen-activated protein kinase, nuclear factor-κB, and caspase-1. Furthermore, galangin attenuated IgE-mediated passive cutaneous anaphylaxis and the expression of histamine receptor 1 at the inflamed tissue. The inhibitory effects of galangin were more potent than cromolyn, a known anti-allergic drug. Our results showed that galangin down-regulates mast cell-derived allergic inflammatory reactions by blocking histamine release and expression of pro-inflammatory cytokines. In light of in vitro and in vivo anti-allergic inflammatory effects, galangin could be a beneficial anti-allergic inflammatory agent. © 2013 Elsevier Ltd. Source


Cho S.J.,Gyeongnam National University of Science and Technology | Kwon H.S.,Korea Promotion Institute for Traditional Medicine Industry
Journal of Applied Biological Chemistry | Year: 2015

Five phenylpropanoids (1-5), a benzofuran neolignan (6), two 8-O-4′-neolignans (7-8), and five tetrahydrofuran lignans (9-13) were isolated from a methanol extract of Myristica fragrans seeds. The structures of 1-13 were determined by1Hand13C-NMR spectroscopic data analyses and a comparison with the literature data. Compound 3 was isolated for the first time from this plant. All the isolated compounds were evaluated for their inhibitory activity against tyrosinase. Among them, safrole (1) showed significant inhibitions against both the monophenolase (IC50=32.11 μM) and diphenolase (IC50=27.32 μM) activities of tyrosinase. The kinetic analysis shows that safrole (1) is competitive inhibitors for both monophenolase and diphenolase. The apparent inhibition constant (Ki) for safrole (1) binding with free enzyme was determined to be 16.05 and 13.66 μM for monophenolase and diphenolase, respectively. © The Korean Society for Applied Biological Chemistry 2015. Source


Kim H.H.,Chung - Ang University | Kim D.H.,Korea Promotion Institute for Traditional Medicine Industry | Kim M.H.,Chung - Ang University | Oh M.H.,Chung - Ang University | And 3 more authors.
Archives of Pharmacal Research | Year: 2013

The leaves of Myrica rubra sieb. et zucc. have been used in oriental traditional medicine for the treatment of burns, skin diseases, and as an antidiarrheal in China, Japan, and Korea. Activity guided isolation of the leaves of M. rubra has led to the isolation of five flavonoid: myricetin (1), myricitrin (2), myricetin 3-O-(2″-O-galloyl)-α-L-rhamnopyranoside (3), myricetin 3-O-(2″-O-galloyl)-β-D-galactopyranoside (4), and quercetin 3-O-(2″-O-galloyl)-β-D-galactopyranoside (5). All isolates were evaluated for their antioxidant potency against the superoxide anion (O2 -), and compounds 3-5 showed potent scavenging activities with 50 % inhibition concentration (IC50) values compared to the positive control, allopurinol. Compounds 1-5 were evaluated as inhibitors of various macrophage functions involved in the inflammatory process. These five compounds significantly and dose dependently inhibited lipopolysaccharide (LPS)-stimulated nitric oxide (NO), pro-inflammatory cytokines, and the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 macrophages. Our results suggest that galloyl flavonol glycosides (3-5) isolated from M. rubra might be beneficial for the treatment of inflammationa-related diseases. © 2013 The Pharmaceutical Society of Korea. Source

Discover hidden collaborations