• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.343-353
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• 2015

The purpose of this study includes: Firstly, to examine the effects of corporate entrepreneurship on market orientation, radical innovation, and organizational performance. Secondly, to examine the mediating effect of the market orientation, radical innovation on the relationship between corporate entrepreneurship and organizational performance. In order to verify the relationships and mediating effect, data were collected from convenient sample of 269 employees at small and medium enterprises in Busan, Ulsan, Gyeongju city to test theoretical model and its hypotheses. All data collected from the survey were analyzed using with SPSS 18.0 and AMOS 18.0. This study reports findings as followed: first, the relationship between the corporate entrepreneurship and the market orientation is positively related. Second, there was also a positive correlation between the corporate entrepreneurship and the radical innovation. Third, there was also a positive correlation between the market orientation and the radical innovation. Fourth, the relationship between the market orientation and the organizational performance is positively related. Fifth, there was also a positive correlation between the corporate entrepreneurship and the organizational performance. Sixth, there was also a positive correlation between the radical innovation and the organizational performance. Finally, the market orientation played as a partial mediator on the relationship between corporate entrepreneurship and radical innovation. The market orientation and radical innovation played as a partial mediator on the relationship between corporate entrepreneurship and organizational performance. Also, the radical innovation played as a partial mediator on the relationship between market orientation and organizational performance. Based on these findings, the limitations of the study and some directions for future studies were presented.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3143-3155
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• 2014

This tutorial review provides a general account of the electrochemical behavior of quinones and their various applications. Quinone electrochemistry has been investigated for a long time due to its complexity. A simple point of view is developed that considers the relative stability of the reduced quinone species and the values of the first and second reduction potentials. The 9-membered square scheme in buffered aqueous solutions is explained and semiquinone radical stability is discussed in this context. Quinone redox reaction has also been employed in various studies. Diverse examples are presented under three broad categories defined by the roles of quinone: molecular tool for physical chemistry, versatile electron mediator, and charge storage for energy conversion devices.

• Biomolecules & Therapeutics
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• v.9 no.3
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• pp.188-193
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• 2001

Free radical scavengers or quenching agents for reactive oxygen species (ROS) present in consumable fruits, vegetables, and beverages have received considerable attention as potential antioxidants, and thus uses for treatment of several human diseases. In this study, grapevine shoot extract (GSE) containing high concentration of resveratrol and viniferine was evaluated for antioxidant potential and inhibition of pro-inflam-matory mediator production. Utilizing 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and xanthine oxidase (XOD) inhibition assay the GSE showed inhibitory effects of DPPH radical scavenging and XOD activity with the $IC_{50}$/ values of 34.5 and 155 $\mu\textrm{g}$/ml, respectively. In addition, GSE also exhibited the inhibition of prostaglandin E$_2$ (PGE$_2$) and nitric oxide (NO) production in lipopolysaccharide (LPS)-induced mouse macrophage RAW264.7 cells with the $IC_{50}$/ value of 6.4 and 14.5 $\mu\textrm{g}$/ml, respectively. This result suggests that grapevine shoot extract has the potential activity as a natural antioxidant or antiinflammatory agent.

• KSBB Journal
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• v.16 no.2
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• pp.179-182
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• 2001

The use of 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid)(ABTS) as a radical mediator enhanced the bleaching efficiency of kraft pulp by horseradish peroxidase(HRP) and $H_2O_2$. High concentrations of up to 20 mM $H_2O_2$. were used. The bleaching of the kraft pulp increased as the amount of HRP and ABTS concentration were inceased up to 0.3 mg/90 mL and 2 mM, respectively. The bleaching of the kraft pulp was closely related with the HRPs activity and its adsorption onto the pulp. The activity of HRP and bleaching of kraft pulp were maximum at pH 7 and were reduced either in a acidic or alkaline solutions. The adsorption of HRP onto pulp was low in solutions of pH 6-8 and high in an acidic(pH5) and an alkaline solutions(pH 9). The adsorption of the enzyme was greater for alkali-lignin than for crystalline cellulose, the two major components of pulp.

• Natural Product Sciences
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• v.16 no.2
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• pp.111-115
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• 2010

Anti-inflammatory and anti-oxidant effect of Spirodela polyrrhiza (Lemnaceae), a widely used traditional medicinal plant were investigated. In macrophages nitric oxide (NO) is released as an inflammatory mediator and has been proposed to be an important modulator of many pathophysiological conditions including inflammation. 85% MeOH extracts of S. polyrrhiza (0.01, 0.1, 1 mg/mL) suppressed nitric oxide production in interferone-$\gamma$ (IFN-$\gamma$) and lipopoloysaccharide(LPS)-stimulated macrophages. It also attenuated the expression of inflammatory enzymes like inducible NOS (iNOS) and cyclooxygenase-2(COX-2) as assessed by immunoblotting with specific antibodies. Moreover, the values obtained with DPPH radical, superoxide anion and NO radical scavenging assay showed that S. polyrrhiza has potent antioxidant properties as a natural ROS scavenger. The results of the present study suggest the potential use of S. polyrrhiza in the treatment of ROS-mediated chronic inflammatory diseases such as atherosclerosis and rheumatoid arthritis.

• Korean Journal of Acupuncture
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• v.29 no.3
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• pp.406-420
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• 2012

Objectives : Scutellaria barbata has been widely used in oriental medicine used for treatment of acute and chronic inflammatory diseases. In this study, to investigate the protective effect of Scutellaria barbata on type I allergic response, we determined whether Scutellaria barbata inhibits early or late allergic responses. Methods : To assess the effect of Scutellaria barbata Pharmacopuncture Extract(SB) in RBL-2H3 cells, we investigated the levels of the markers of degranulation such as ${\beta}$-hexosaminidase and histamine, inflammatory mediator such as IL-4, TNF-${\alpha}$, PGE2 and cysLT, and mRNA expression of cytokines and enzymes. In addition, we determined the levels of intracellular ROS by DCFH-DA assay and the free radical scavenging activity by DPPH method. Results : We found that SB suppressed the release of ${\beta}$-hexosaminidase and histamine and the production of IL-4, TNF-${\alpha}$, PGE2 and cysLT in RBL-2H3 by the antigen stimulation. SB also significantly inhibited the enzyme mRNA expressions, such as HDC2, COX-1, COX-2, 5-LOX and iNOS2, along with reduced cytokine mRNA expressions, such as IL-$1{\beta}$, IL-2, IL-3, IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ and GM-CSF in RBL-2H3. In addition, SB suppressed the levels of intracellular ROS. Conclusions : Our results indicate that SB protects against type I allergic response and exert an anti-inflammatory effect through the inhibition of degranulation, inflammatory mediator release and mRNA expression of cytokines and enzymes.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.132-137
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• 2003

Antioxidant and anti-inflammatory potentials of various grape extracts were evaluated. Extracts from Kyho seed, Kyho stem, and Campbell seed showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities compared to resveratrol $(IC_{50}=16.9,\;21.5,\;21.9,\;34.6\;{\mu}g/mL,\;respectively)$, among which, antioxidant effect of Kyho seed extract were similar to that of vitamin C $(IC_{50}=12.2\;{\mu}g/mL)$. These extracts also exhibited inhibitory activities on lipopolysaccharide (LPS)-induced prostaglandin $E_2$ production and nitrite formation in mouse macrophage RAW 264.7 cells at $50\;{\mu}g/mL$. Kyho stem and seed extracts showed growth inhibitory activities in human lung and colon cancer cells. These results suggest the potential roles of grape extracts as antioxidants and anti-inflammatory agents.

• The Korean Journal of Pharmacology
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• v.21 no.1
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• pp.12-26
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• 1985

The generation of $O^{-}_{2}{\cdot}$ and its toxic effects were studied with rat brain mitochondria. The production of $O^{-}_{2}{\cdot}$ from mitochondria in the presence of succinate and antimycin was demonstrated by SOD-inhibitable reduction of NBT. Although succinate can support the $O^{-}_{2}{\cdot}$ formation, the highest rate needs antimycin indicating that blockade of electron flow in the respiratory chain augments the univalent reduction of molecular oxygen. Under this condition, $H_2O_2$ was also observed to be produced. But its formation appears to be derived from the dismutation of the primary product, $O^{-}_{2}{\cdot}$ since the rate of $H_2O_2$ production was markedly decreased by NBT and ferricytochrome c. The $O^{-}_{2}{\cdot}$ and $H_2O_2$ produced were able to cause toxic actions to mitochondrial and extra-mitochondrial components as shown by lipid peroxidation of mitochondrial membrane, and inactivation and lysis of isocitrate dehydrogenase and erythrocytes added to the medium, respectively. In all the toxic actions observed, $Fe^{++}$ was required. It appears that in the toxic actions $OH{\cdot}$ generated from the iron-catalyzed Haber-Weiss reaction acts as a mediator. This was supported by the finding that mitochondria in the presence of succinate and antimycin produced ethylene from methional, and $Fe^{++}$ added increased the ethylene production. The observed toxic actions of mitochondrial $O^{-}_{2}{\cdot}$ may provide evidence supporting a potential role of mitochondria as a source of oxygen radicals to cause tissue damage.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2000.05a
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• pp.13-20
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• 2000

Melatonin, a chemical mediator produced in the mammalian pineal gland and several other organ, is a ubiquitously acting antioxidant. It has been shown to scavenge the hydroxyl radical (ㆍOH), singlet oxygen ($^1$O$_2$) and the peroxynitrite anion (ONOO-). In addition, melatonin reportedly stimulates a number of antioxidative enzymes including glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase. Antioxidative effect of melatonin in pharmacological and physiological level was investigated using hepatocarcinogen 2-nitropropane (2-NP) and pinealectornized (Px) rats, respectively. Lipid peroxidation (LPO) as indicated by malondialdehyde and 4-hydroxyalkenals and DNA damage as indicated by 8-hydroxydeoxyguanosine (8-OH-dG) induced by 2-NP were prevented by melatonin. The degree of LPO and DNA damage in Px rats were higher than those of intact old and young ones suggesting the removal of pineal gland resulted in higher accumulation of oxidative damage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.853-859
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• 2009

Nardostachys chinensis has been used widely as a traditional medicine for the treatment of diverse diseases. The dried plant was extracted with 85% methanol extract (NC). We investigated the antioxidant properties of NC on the 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, superoxide anion and nitric oxide radical scavenging capacity under in vitro assays. NC showed potent antioxidant activity, compared to ascorbic acid. In macrophages, nitric oxide is released as an inflammatory mediator and has been proposed to be an important modulator of many pathophysiological conditions in inflammation. In the present study, it was also investigated that the inhibition effects on NO and the mechanism of down-regulation of immune response by NC in IFN-IFN-$\gamma$/LPS-stimulated mouse (C57BL/6) peritoneal macrophages. Extracts of NC suppressed NO production and the expression of iNOS and COX-2. The present results indicate that NC has an antioxidant and anti-inflammatory properties and therefore may be beneficial in diseases which related to oxidative stress-mediated chronic inflammatory disorders.