• The Korean Journal of Pharmacology
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• v.30 no.3
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• pp.337-342
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• 1994

It is well known that angiotensin converting enzyme inhibitors(ACEIs) increase endothelium-dependent relaxation in aortic strips of spontaneously hypertensive rats(SHR) and this increase in relaxation may be due to altered endothelial nitric oxide breakdown. But there are few studies on the effect of the angiotensin II receptor blocker on the nitric oxide-mediated relaxation. So we attempted to investigate the effect of angiotensin II receptor blocker on the nitric oxide-dependent relaxation in isolated aorta of SHR. Two week-treatment of losartan (30 mg/kg/day) increased the acetylcholine$(10^{-9}\;to\;10^{-5}\;M)$-and histamine$(10^{-8}\;to\;10^{-4}\;M)$-induced relaxation in endothelium intact strips but 90 minutes-treatment of losartan $(10^{-4}\;M)$ showed no increase in relaxation. The phenylephrine $(10^{-7}\;M)$-induced contraction, repeated every 2 hours, was diminished gradually following lipopolysaccharide (LPS)-treatment $(100\;{\mu}g/ml)$ but there was no significant difference in enalapril- and losartan-treated group compared with control group. These results suggest that activity of the endothelial constitutive NO synthase may be changed by chronic treatment of angiotensin II receptor blockers and ACEIs but angiotensin II antagonist and ACEI have no effect on the inducible NO synthase activity in the isolated aorta of SHR

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.69-77
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• 2002

Oxidative stress derived from reactive oxygen species (ROS) is one of the major damaging factors in plants exposed to environmental stress. In order to develop the platform technology to solve the global food and environmental problems in the 21st century, we focus on the understanding of the antioxidative mechanism in plant cells, the development of oxidative stress-inducible antioxidant genes, and the development of transgenic plants with enhanced tolerance to stress. In this report, we describe our recent results on industrial transgenic plants by the gene manipulation of antioxidant enzymes. Transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts were developed and were evaluated their protection effects against stresses, suggesting that simultaneous overexpression of both SOD and APX in chloroplasts has synergistic effects to overcome the oxidative stress under unfavorable environments. Transgenic tobacco plants expressing a human dehydroascorbate reductase gene in chloroplasts were showed the protection against the oxidative stress in plants. Transgenic cucumber plants expressing high level of SOD in fruits were successfully generated to use the functional cosmetic purpose as a plant bioreactor. In addition, we developed a strong oxidative stress-inducible peroxidase promoter, SWPA2 from sweetpotato (lpomoea batatas). We anticipate that SWPA2 promoter will be biotechnologically useful for the development of transgenic plants with enhanced tolerance to environmental stress and particularly transgenic cell lines engineered to produce key pharmaceutical proteins.

• Korean Journal of Microbiology
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• v.24 no.2
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• pp.133-140
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• 1986

Extracts of CO-autotrophically grown cells of Acinetobacter sp. 1 were shown to use thionin, methylene blue, or 2,6-dichlorophenol-indophenol, but not NAD, NADP, FAD, or FMN, as electron acceptors for the oxidation of CO under strictly anaerobic conditions. The CO dehydrogenase (CO-DH) in the thes bacterium was found to be an inducible enzyme. The enzyme activity was determined by an assay based on the CO-dependent reduction of thionin. Maximal reaction rates were found at pH 7.5 and $60^{\circ}C$, and the Arrhenius plot revealed an activation energy of 6.1 kcal/mol(25.5kJ/mol). THe $K_m$ m/ for CO was $154{\mu}M$. Known metalchelating agents tested had no effects on the CO-DH activity. No divalent cations tested affect the enzyme activity significantly escept $Cu^{2+}$ which suppressed the activity completely. The enzyme was inhibited by glucose and succinate. The same extracts catalyzed oxidation of hydrogen gas and formate with thionin as electron acceptor. The CO-DH of Acinetobacter sp. 1 was to have no immunological relationship with that of Pseudomonas carboxydohydrogena.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.39-50
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• 2019

Mitogen-activated protein (MAP) kinases play an important role in cell growth and differentiation, as well as the modulation of proinflammatory cytokines. The objective of this study was to examine the increase in the anti-inflammatory effect of Gentiana scabra Bunge (GSB), due to bioconversion with the Aspergillus kawachii crude enzyme, via inhibition of the $NF-{\kappa}B$ signaling and MAP kinase pathways in RAW 264.7 cells. The expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 in RAW 264.7 cells treated with the GSB ethyl acetate fraction bioconverted with A. kawachii crude enzyme (GE-BA), was dramatically suppressed as compared to GSB ethyl acetate fraction non-bioconverted with the A. kawachii crude enzyme (GE-UA). The phosphorylation of p38, extracellular signal-regulated kinases, and inhibitory ${\kappa}B$ in RAW 264.7 cells treated with GE-BA was further suppressed, as compared to exposure to GE-UA. Moreover, the mRNA expression of interleukin 6, interleukin 1-beta, and tumor necrosis $factor-{\alpha}$ was further suppressed by GE-BA, compared to GE-UA. Similarly, anti-oxidant activities, such as 2,2-diphenyl-1-picrylhydrazyl hydrate and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity, of GE-BA were further increased compared to GE-UA. These observations demonstrate that the anti-oxidant and anti-inflammatory activities of GSB ethyl acetate fraction increases as a result from bioconversion with the A. kawachii crude enzyme.

• Journal of Life Science
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• v.23 no.6
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• pp.743-750
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• 2013

The aim of this study is to develop a supplementary therapeutic agent capable of promoting vascular circulation. The effects of Acai berry ethanolic extracts (ABEE) on activity of angiotensin converting enzyme from rabbit lung, production of nitro oxide in both murine macrophage cells and vascular endothelial cells as well as antioxidant effects were investigated in this study. First of all, it was observed the direct effects of ABEE on reducing power and antioxidant effect lipid peroxidation. In addition, ABEE showed a protective effect on DNA oxidation induced by hydroxyl radical. Furthermore, ABEE at 0.01% exerted approximately 50% inhibition on activity of angiotensin converting enzyme. ABEE increased the production of nitric oxide in endothelial cells, but decreased the induction of nitric oxide stimulated by lipopolysaccharide in microphage. The expression levels of superoxide dismutase (SOD)-2 and -3 were enhanced by ABEE treatment, however, the expression level of SOD-1 remained constant. Moreover, the expression level of nitric oxide synthases-1 (NOS-1), a constitutive enzyme, was increased by ABEE, but that of NOS-2, a inducible enzyme, was constant. It was also found that the level of Nrf-2, a transcription factor of SOD, was increased by ABEE. Therefore, these results demonstrate that ABEE could promote blood circulation via above actions, suggesting that may be helpful for health of blood vessel.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.281-288
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• 2002

Recombinant Escherichia coli strain harboring the ${\lambda}$pR-pL promotor and heterologus poly-${\beta}$-hydroxybutyrate (PHB) biosynthesis genes was used to investigate the effect of culture conditions on the efficient PHB production. The expression of phb genes was induced by a temperature upshift from $33^{\circ}C\;to\;38^{\circ}C$. The protein expression levels were measured by using two-dimensional electrophoresis, and the enzyme activities were also measured to understand the effect of culture temperature, carbon sources, and the dissolved oxygen (DO) concentration on the metabolic regulations. AcetylCoA is an important branch point for PHB production. The decrease in DO concentration lowers the citrate synthase activity, thus limit the flux toward the TCA cycle, and increase the flux for PHB production. Since NADPH is required for PHB production, the PHB production does not continue leading the overproduction of acetate and lac-tate. Based on these observations, a new operation was considered where DO concentration was changed periodically, and it was verified its usefulness for the efficient PHB production by experiments.

• Herbal Formula Science
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• v.15 no.1
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• pp.199-211
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• 2007

Inducible nitric oxide synthase (iNOS) are important inflammation enzyme and severe up-nitric oxide (NO) production by this enzyme has been intricated with pathogenesis of inflammation diseases as atopy dermatitis. The present study was designed in order to determine whether Sopungdojeok-san could inhibit atopy dermatitis through modulation of iNOS mRNA expression and NO production, We found that iNOS mRNA expression and NO production in RAW 264.7 macrophages stimulated with lipopolysaccharide dose-dependantly decreased by Sopungdojeok-san extract treatment (0.4 - 1.0 mg/ml). The distribution of iNOS positive reacted cell in atopy dermatitis elicited skin of mice were remarkably decreased by Sopungdojeok-san administration (2.5 ml/kg/day). The SOD ability of Sopungdojeok-san were dose-dependantly increased from 0.6 mg/ ml than butylated hydroxyanisole. These data likely indicate that Sopungdojeok-san may act as inflammatory regulator for atopy dermatitis may be possible to develop useful agent for chemopreventation of NO-intricate inflammatory diseases.

• Toxicological Research
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• v.11 no.1
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• pp.31-36
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• 1995

Cyclophosphamide (CP) must be enzymatically activated by cytochrome P450(CYP)-linked mixed-function oxidation pathway to be either mutagenic or teratogenic. Influences of alterations in hepatic mixed-function oxidase acitivity and glutathione (GSH) content on the embryotoxicity of CP were studied in rat whole embryo culture system. The embryotoxicity of CP was compared using rat S-9 fraction (S-9) pretreated with chemicals inducing different CYP isozymes, acetone (ACE), Aroclor 1254 (ARO), $\beta$-naphthoflavone (NAF) and phenobarbital (PHE). When 10.5 day embryos were cultured in the immediately centrifuged rat serum for 48 hrs using general gas char{ging schedule, CP$(40{\mu}g/ml)$ with S-9 induced by either NAF or PHE increased the incidence of realformations and significantly decreased embryonic growth compared with the non-induced S-9 group. ACE or ARO induced S-9 group showed no significant difference in embryonic growth. These data suggest that PB and/or NAF inducible CYP isoenzymes are mainly involved in the activation of CP. To examine the effect of GSH on the embryotoxicity of CP, 10.5 day embryos were exposed to CP and S-9 after preincubation with 10 mM of GSH for 3 hrs. In the GSH pretreated group the growth of embryos increased significantly compared with that of the untreated group, suggesting that GSH may protect embryos in culture from some toxic effects of CP.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1092-1098
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• 2007

Inducible nitric oxide synthase (iNOS) are important inflammation enzyme and severe up-nitric oxide (NO) production by this enzyme has been intricate with pathogenesis of atopy dermatitis. The present study was designed in order to determine whether Cheonggi-san could inhibit atopy dermatitis through modulation of iNOS mRNA expression and NO production. We found that iNOS mRNA expression and NO production in RAW 264.7 macrophages stimulated with lipopolysaccharide dose-dependantly decreased by Cheonggi-san extract treatment (0.5 - 2.0 mg/ml). The distribution of iNOS positive reacted cell in NC/Nga mice with atopy dermatitis were decreased by Cheonggi-san extract treatment (2.5 ml/kg/day) and apoptosis were increased. These data likely indicate that Cheonggi-san may act as inflammatory regulator for atopy dermatitis and may be possible to develop useful agent for chemoprevention of NO intricate inflammatory diseases.

• Applied Biological Chemistry
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• v.27 no.1
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• pp.45-51
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• 1984

Kluyveromyces marxinus LG contains an inulase activity which is inducible by growth on inulin. The highest enzyme activity obtained at the initial stage of stationary phase of growth curve. The partially purified inulase hydrolyzed inulin, sucrose and raffinose. This enzyme showed the maximal activity at pH 4.0 and temperature of $55^{\circ}C$ for inulin and sucrose. It was also markedly inhibited by $Hg^{++}\;and\;Ag^{+}$ but not EDTA. This inulase was charaterized as a undo type which contains invertase activity and Km values for inulin and sucrose were $1.2{\times}10^{-2}M\;and\;1.3{\times}10^{-4}M$, respectively.