• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.437-440
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• 2003

In a mediator-aided microbial fuel cell, the choice of a proper mediator is one of the most important factors for the development of a better fuel cell system as it transfers electrons from bacteria to the electrode. The electrochemical behaviors within the lipid layer of two representative mediators, thionin and safranine O both of which exhibit reversible electron transfer reactions, were compared with the fuel cell efficiency. Thionin was found to be much more effective than safranine O though it has lower negative formal potential. Cyclic voltammetric and fluorescence spectroscopic analyses indicated that both mediators easily penetrated the lipid layer to pick up the electrons produced inside bacteria. While thionin could pass through the lipid layer, the gradual accumulation of safranine O was observed within the layer. This restricted dynamic behavior of safranine O led to the poor fuel cell operation despite its good negative formal potential.

• Journal of Ginseng Research
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• v.39 no.3
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• pp.189-198
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• 2015

Background: Antiallergic effect of 20(S)-protopanaxatriol (PPT), an intestinal metabolite of ginseng saponins, was investigated in guinea pig lung mast cells and mouse bone marrow-derived mast cells activated by a specific antigen/antibody reaction. Methods: Increasing concentrations of PPT were pretreated 5 min prior to antigen stimulation, and various inflammatory mediator releases and their relevant cellular signaling events were measured in those cells. Results: PPT dose-dependently reduced the release of histamine and leukotrienes in both types of mast cells. Especially, in activated bone marrow-derived mast cells, PPT inhibited the expression of Syk protein, cytokine mRNA, cyclooxygenase-1/2, and phospholipase $A_2$ ($PLA_2$), as well as the activities of various protein kinase C isoforms, mitogen-activated protein kinases, $PLA_2$, and transcription factors (nuclear factor-${\kappa}B$ and activator protein-1). Conclusion: PPT reduces the release of inflammatory mediators via inhibiting multiple cellular signaling pathways comprising the $Ca^{2+}$ influx, protein kinase C, and $PLA_2$, which are propagated by Syk activation upon allergic stimulation of mast cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.5
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• pp.830-836
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• 2011

The leaf of mulberry (Morus alba L) has long been used in Oriental medicine for the prevention or treatment of several diseases. However, little is known about the inhibitory effects of a single compound isolated from the mulberry leaves on inflammatory response. We are isolate a single compound of quercetin (3,3',4',5,7-pentahydroxyflavone) and astragalin (kaempferol-3-O-glucopyranoside) from the mulberry leaves, and then investigate the anti-inflammatory effects of quercetin, astragalin or quercetin plus astragalin in lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages. Each compound suppressed the production of inflammatory mediators (NO, $PGE_2$ and IL-6) in LPS-stimulated murine peritoneal macrophages in a dose-dependent manner. Especially, the cotreatment of quercetin (2.5 ${\mu}M$) and astragalin (2.5 ${\mu}M$) markedly suppressed the production and the expression of inflammatory mediators. These suppressive effects were synergistically increased by their combination. These results suggest that the combination of quercetin and astragalin from the mulberry leaves may be useful for therapeutic drugs against inflammatory immune diseases, probably by suppressing the production of inflammatory mediators.

• Natural Product Sciences
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• v.15 no.4
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• pp.185-191
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• 2009

Intestinal epithelial cells (IEC) play an important role in the mucosal immune system. IEC-derived mediators of inflammatory cascades play a principal role in the development of colon inflammation. The aim of this study was to investigate the inhibitory effect of aqueous extracts of Schizandra chinensis fruits (SC-Ex) on the production of inflammatory mediators by the human colonic epithelial cells. HT-29 cells were stimulated with dextran sulfate sodium in the presence or absence of SC-Ex to examine the cytoprotection and production of IL-8 and reactive oxygen species (ROS). It was shown that dextran sulfate sodium (DSS) caused the reduction of cell viability and production of IL-8 and ROS in DSS-treated HT-29 cells. We observed that the treatment of SC-Ex protected significantly cell proliferation from DSS-induced damage in dose-dependent manner. SC-Ex (10 and 100 ${\mu}g$/ml) also suppressed DSS-induced production of IL-8 mRNA and protein. Moreover, DSS-induced ROS production was inhibited markedly by the treatment of 100 ${\mu}g$/ml SC-Ex. These results suggest that SC-Ex has the protective effects on DSS-induced cell damage and the release of inflammatory mediators in the intestinal epithelial cells.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.1
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• pp.81-89
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• 2018

This study evaluated the anti-asthmatic activities of 2,6-di-tert-butyl-4-hydroxymethylphenol (DBHP) that is a potent phenolic antioxidant in edible vegetable oil. The effects of DBHP on bronchial asthma were evaluated by determining the specific airway resistance (sRaw) and tidal volume (TV) during the immediate asthmatic response (IAR) and the late-phase asthmatic response (LAR) in guinea pigs with aerosolized ovalbumin-induced asthma. Recruitment of leukocytes and the levels of biochemical inflammatory mediators were determined in the bronchoalveolar lavage fluids (BALFs), and histopathological surveys performed in lung tissues. DBHP significantly inhibited the increased sRaw and improved the decreased TV on IAR and LAR, and also inhibited recruitment of eosinophils and neutrophils into the lung, and release of biochemical inflammatory mediators such as histamine and phospholipase $A_2$ from these infiltrated leukocytes, and improved pathological changes. However, anti-asthmatic activities of DBHP at oral doses of 12.5 to 50 mg/kg was less than those of dexamethasone (5 mg/kg, p.o.) and cromoglycate (10 mg/kg, p.o.), but more potent or similar to that of salbutamol (5 mg/kg, p.o.). These results in the present study suggest that anti-asthmatic effects of DBHP in the guinea pigs model of OVA-induced asthmatic responses principally are mediated by inhibiting the recruitments of the leukocytes and the release of biochemical inflammatory mediators from these infiltrated leukocytes.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.47-51
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• 2005

The bioelectrochemical reduction of nitrate in the presence of various mediators including methyl viologen and azure A was studied using a 3-electrode voltammetric system. The catalytic potential for the reduction of the mediators was observed in the reactor, which for methyl viologen and azure A were -0.74 V and -0.32 V, respectively, with respect to the potential of Ag/AgCl reference electrode. This potential was then applied to a working electrode to reduce each mediator for enzymatic nitrate reduction. Nitrite, the product of the reaction, was measured to observe the enzymatic nitrate reduction in the reaction media. Methyl viologen was observed as the most efficient mediator among those tested, while azure A showed the highest electron efficiency at the intrinsic reduction potential when the mediated enzyme reactions were carried out with the freely solubilized mediator. The electron transfer of azure A with respect to time was due to the adhesion of azure A to the hydrophilic surface during the reduction. In addition, the use of the adsorbed mediator on conductive activated carbon was proposed to inhibit the change in the electron transfer rate during the reaction by maintaining a constant mediator concentration and active surface area of the electrode. Azure A showed better than nitrite formation than methyl viologen when used with activated carbon.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.301-310
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• 1999

Anthrax caused by Bacillus anthracis is one of the most important zoonotic diseases. The bacterium produces several virulence factors. Of the factors, protective antigen (PA) of tripatite toxin has been identified as a central component in the pathogenesis of anthrax. However, precise roles of PA and other cellular components in the reaction with the target cells remain to be elucidated, especially in the initial stage of the disease. Three B anthracis antigens were prepared for investigation; PA, sonicated cellular antigens (S-Ag) and formalin-inactivaed whole cell antigens (W-Ag). PA was purified from culture supernatant of the bacterium using FPLC system with MonoQ. S-Ag and W-Ag were prepared by sonication and formalin inactivation of the cultured cells, respectively. Purity of the antigens was confirmed by SDS-PAGE and Western blot analysis. The roles of these antigens in the production of inflammatory mediators such as NO, IL-6 and $TNF{\alpha}$ from mouse peritoneal macrophages were investigated. PA alone did not induce the production of the inflammatory mediators while the other antigens, S-Ag and W-Ag, did in a dose and time dependent manner. These results suggested that in addition to major virulence factors, other cellular antigens are also involved in the initial stage of the disease by the induction of inflammatory mediators.

• Herbal Formula Science
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• v.18 no.2
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• pp.183-199
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• 2010

Rheumatoid arthritis is characterized by the focal loss of cartilage due to an up-regulation of inflammatory pathways, which produce inflammatory mediators, such as interleukin-1beta(IL-$1{\beta}$), IL-6, tumour necrosis factor alpha(TNF-$\alpha$), prostaglandin, and nitric oxide(NO). We investigated the anti-arthritic effects of water extract from FLOS LONICERAE(FLWE) in vitro and in vivo. Extract inhibited the production of inflammatory mediators(NO, IL-$1{\beta}$, TNF-$\alpha$, and prostaglandin $E_2$) and the expression of inducible NO synthase(iNOS) and cyclooxygenase-2(COX-2) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in a dose-dependent manner. FLWE also inhibited TNF-$\alpha$, IL-$1{\beta}$, IL-6, and $PGE_2$ production as well as COX activity in collagen-induced mouse arthritis. Moreover, FLWE significantly suppressed collagen-induced mouse arthritis. These results suggest that FLOS LONICERAE may be useful for therapy against inflammatory immune diseases and rheumatoid arthritis, probably by suppressing the production of inflammatory mediators.

• YAKHAK HOEJI
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• v.60 no.1
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• pp.8-14
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• 2016

Endotoxemia induces production of inflammatory mediators and acute phase proteins, leading to multiorgan injury and systemic inflammation. Hypothalamic-pituitary-adrenal (HPA) axis activation and glucocorticoids (GCs) release modify endotoxemia-induced inflammatory responses. In the present study, we investigated whether pre-exposure of GCs influences endotoxin-induced production of inflammatory mediators in hepatocytes. Hepa1c1c-7 cells were pretreated with low concentrations of corticosterone for 24 h and then cultured without corticosterone in the presence or absence of LPS. Our results demonstrated that LPS alone significantly enhanced production of IL-6 and CRP but reduced vascular endothelial growth factor (VEGF) compared to controls. Combination of corticosterone pretreatment and LPS significantly upregulated production of IL-6, IL-$1{\beta}$, and VEGF but downregulated CRP compared to those in LPS alone. These findings suggest that in low concentration of corticosterone-preexposed hepatocytes, endotoxemia may induce upregulation of IL-6, IL-$1{\beta}$, VEGF and but downregulation of CRP.

• Journal of Periodontal and Implant Science
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• v.38 no.3
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• pp.511-520
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• 2008

Purpose: Diabetes mellitus is a clinically and genetically heterogeneous group of metabolic disorders manifested by abnormally high levels of glucose in the blood. Mounting evidence demonstrates that diabetes is a risk factor for gingivitis and periodontitis. The circulating mononuclear phagocytes in diabetic patients with hyperglycemia are chronically exposed to high level of serum glucose. Thus, this study attempted to determine the effect of pre-exposure of monocytes and macrophages to high concentration of glucose on lipopolysaccharide (LPS)-induced production of pro-inflammatory mediators. Material and Methods: For this purpose, cells were cultured in medium containing normal (5 mM) or high glucose (25 mM) for 4-5 weeks before treatment for 24 h with LPS. LPS was highly purified from Porphyromonas gingivalis or Prevotella intermedia by phenol extraction. Result: Results showed that prolonged pre-exposure of cells to high glucose markedly increased LPS-stimulated NO secretion when compared to normal glucose. In addition to NO, high glucose also augmented LPS-stimulated IL-6, IL-8, and TNF-$\alpha$ secretion after cells were exposed to high glucose for 4 weeks. Conclusion: The present study demonstrates that pre-exposure of mononuclear phagocytes with high glucose augments LPS-stimulated production of pro-inflammatory mediators. These findings may explain why periodontal tissue destruction in diabetic patients is more severe than that in non-diabetic individuals.