• Biomolecules & Therapeutics
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• v.3 no.3
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• pp.188-191
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• 1995

The Present study was undertaken to indicate the major source of NO by liver cells in vitro. Even at early stages of induction or low LPS concentrations, NO was produced at high rates by LPS(Lipopolysaccharide) on the isolated rat kupffer cells. PMA(phorbol 12-myristate 13-acetate) induced NO formation at low rates in the same cells. IFN-${\gamma}$ (Interferon-${\gamma}$) alone had not induced NO formation but it stimulated the effects of LPS. Calcium ionophore A23187 caused no stimulatory effect. It suggests that LPS has especially strong NO inducer on the kupffer cells and its mechanism is related to those on macrophage in other organs. In other nonparenchymal liver cells, sinusoidal endothelial cells were not stimulated to produce NO either by inducers of aortic endothelium(A23187, ATP and ADP) or by effectors of macrophages(LPS, IFN-${\gamma}$. This results suggest that rat liver kupffer cells appear to be the major source of NO by liver cells in vitro. But in vivo, liver endothelial cells may still be capable of producing NO. Furthermore, kupffer cells may produce factors that facilitate NO production by the endothelial cells.

• Journal of Food Hygiene and Safety
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• v.8 no.4
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• pp.181-188
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• 1993

It is well known that bacterial lipopolysaccharide (LPS) stimulates the prostaglandin (PG) synthesis in various experimental system, but the mechanism and the detailed nature of its action are yet to be understood. Thus, this study was designed to characterize LPS induced PG synthesis in rat alveolar macrophage. Although results were not so much prominent, LPS stimulated PGE2 synthesis in macrophage with short term exposure, and this was thought to be mainly due to the activation of phopholipase A2+ But there was a burst in the PG synthesis 6 hours after the LPS treatment and this was accompanied with the increase of cyclooxygenase activity. This effect was not mediated by tumor necrosis factor (TNF) or platelet activating factor (PAF), and the existence of serum was prerequisite for its action. Growth factors such as epidermal growth factor (EGF) and platelet derived growth factor (PDGF) themselves did not stimulate PG synthesis and the showed stimulatory activities to some extent. Normal rat serum was more effective for the elicitation of the LPS action than growth factors. Thus, considering the amounts of growth fafctors contained in normal serum, it was suggested that another factors like LPS binding protein (LBP) might be involved in the serum effect on LPS action. Conclusively. it was thought that LPS could stimulate PG synthesis through interaction with serum factors such as EGF, PDGF and/or LBP.

• The Journal of Internal Korean Medicine
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• v.34 no.1
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• pp.31-45
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• 2013

Objectives : Gokgisaeng (Korean mistletoe) is used for the treatment of inflammatory and cancer diseases in traditional Korean medicine and its major component lectins have been reported to induce nitric oxide (NO) in RAW 264.7 macrophages, and also induce apoptosis of various types of cancer cells, although its modulatory effects on cancer cell migration and macrophage activation is poorly understood. The aim of this study is to clarify molecular mechanisms of action responsible for the anti-inflammatory and antitumor migration potentials of Korean mistletoe extract (KME). Methods : We investigated the anti-inflammatory activity of KME on NO production and inducible nitric oxide synthase (iNOS) expression by lipopolysaccharide (LPS) in both RAW 264.7 macrophages and rat C6 glioma cells, and also evaluated inhibitory efficacy on glioma cell growth and migration. For assessment, XTT assay, nitrite assay, RT-PCR, scratch-wound and Boyden chamber assay, and western blot analysis were performed. Results : Previously reported, unlike the efficacy of Gokgisaeng lectin, KME inhibited NO production and iNOS expression, and suppressed pro-inflammatory mediators including IL-$1{\beta}$, IL-6, COX-2, iNOS in LPS-stimulated RAW 264.7 cells. Furthermore, KME suppressed tumor cell growth and migration, and it also inhibited LPS-induced NO release and iNOS activation by down-regulating expression of protein kinase C (PKC) and phosphorylation of ERK in C6 glioma cells. Conclusions : Our research findings provide evidence that KME can play a significant role in blocking pro-inflammatory reaction and malignant progression of tumors through the suppression of NO/iNOS by down-regulating of inflammatory signaling pathways, PKC/ERK.

• The Journal of Korean Medicine
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• v.26 no.2 s.62
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• pp.140-151
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• 2005

Objectives: Cinnamomi Ramulus (CR), the young twig of Cinnamomum loureirri nees, has been used for treating symptoms related to pain, rheumatic arthritis and inflammation in Korean herb medicine. This study was carried out to investigate the anti-inflammatory effect of CR in vivo and in vitro. Methods: Extracts of CR were prepared and the chemical components of the extracts were examined by gas chromatography-mass spectrometry (GC-MS). The extracts were administrated to the rat paw edema model induced by carrageenan to evaluate the anti-inflammatory effect of CR. The expressions of nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 were also quantified in lipopolysaccharide(LPS)­induced RAW 264.7 macrophages to survey the effect of CR in vitro. The main components were cinnamaldehyde and coumarin. Results: We examined the anti-inflammatory activity of the $80\%$ ethanol extract of Cinnamomi Ramulus in vivo by using carrageenan-induced rat paw edema model. Maximum inhibition of $54.91\%$ was noted at the dose of l1000mg/kg after 2 hours of drug administration in carrageenan-induced rat paw edema and this showed a potent anti-inflammatory effect. Conclusions: The results showed that Cinnamomi Ramulus suppressed dose-dependently LPS-induced NO production in RAW 264.7 macrophages and also decreased iNOS protein expression. Cinnamomi Ramulus also showed a significant inhibitory effect in LPS-induced PGE2 production and COX-2 expression.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.437-447
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• 1999

Type I diabetes, also known as insulin-dependent diabetes mellitus (IDDM) results from the destruction of insulin-producing pancreatic $\beta$ cells by a progressive $\beta$ cell-specific autoimmune process. The pathogenesis of autoimmune IDDM has been extensively studied for the past two decades using animal models such as the non-obese diabetic (NOD) mouse and the Bio-Breeding (BB) rat. However, the initial events that trigger the immune responses leading to the selective destruction of the $\beta$ cells are poorly understood. It is thought that $\beta$ cell auto-antigens are involved in the triggering of $\beta$ cell-specific autoimmunity. Among a dozen putative $\beta$ cell autoantigens, glutamic acid decarboxylase (GAD) has bee proposed as perhaps the strongest candidate in both humans and the NOD mouse. In the NOD mouse, GAD, as compared with other $\beta$ cell autoantigens, provokes the earliest T cell proliferative response. The suppression of GAD expression in the $\beta$ cells results in the prevention of autoimmune diabetes in NOD mice. In addition, the major populations of cells infiltrating the iselts during the early stage of insulitis in BB rats and NOD mice are macrophages and dendritic cells. The inactivation of macrophages in NOD mice results in the prevention of T cell mediated autoimmune diabetes. Macrophages are primary contributors to the creation of the immune environment conducive to the development and activation of $\beta$cell-specific Th1-type CD4+ T cells and CD8+ cytotoxic T cells that cause autoimmune diabetes in NOD mice. CD4+ and CD8+ T cells are both believed to be important for the destruction of $\beta$ cells. These cells, as final effectors, can kill the insulin-producing $\beta$ cells by the induction of apoptosis. In addition, CD8+ cytotoxic T cells release granzyme and cytolysin (perforin), which are also toxic to $\beta$ cells. In this way, macrophages, CD4+ T cells and CD8+ T cells act synergistically to kill the $\beta$ cells in conjunction with $\beta$ cell autoantigens and MHC class I and II antigens, resulting in the onset of autoimmune type I diabetes.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.513-520
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• 1994

Background: The pathogenesis of silicosis has been focused on the interaction between alveolar macrophages and silica particle. Although fibrosis in silicosis has been studied extensively, the mechanism is still not fully understood. There is increasing evidence that monokines and arachidonic acid metabolites macrophage are involved in pathogenesis of silicosis. Recently, it was reported that prostaglandin E2 produced from macrophage counteracts the stimulatory effects of other monokines on fibroblast proliferation or collagen production. Until now, it was remained uncertain by which mechanism silica particle may activate alveolar macrophage to an enhanced release of prostaglandin E2. Methods: In order to investigate the relationship between the activity of alveolar macrophage and the production of $PGE_2$ from activated alveolar macrophage, the authors measured hydrogen peroxide and $PGE_2$ from alveolar macrophages activated by silica in vitro and from alveolar macrophages in the silicotic nodules from rat. Experimental silicosis was induced by intratracheal infusion of silica($SiO_2$) suspended in saline(50 mg/ml) in Sprague-Dawley rats. Results: produced by 1) The silicotic nodules with fibrosis were seen from the sections of rat lung at 60 days after intratracheal injection with 50 mg aqueous suspension of silica(Fig. 1). 2) In vitro, silica caused the dose dependent increase of hydrogen peroxide(p<0.05, Fig. 2A) and $PGE_2$(p>0.05, Fig. 2B) release from alveolar macrophages. Alveolar macrophages from rat with silicotic nodules released more hydrogen peroxide and $PGE_2$ than those of control group(p<0.05, Fig. 3). Conclusion: These results suggest that silica particle could activate macrophage directly and enhanced the release of $PGE_2$ and hydrogen peroxide from the alveolar macrophage.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.233-239
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• 1998

Stimulated alveolar macrophages and neutrophils produce nitric oxide, a free radical by an inducible nitric oxide synthase(iNOS), which reacts with superoxide anion to form peroxynitrite, a more highly reactive toxic species. The objectives of the present study were to evaluate acute inflammatory lung injury and to determine iNOS mRNA induction and nitric oxide production by rat broncho-alveolar lavage cells following intratracheal treatment of silica. After 4 h exposure to silica, differential counts of broncho-alveolar lavage cells and lactate dehydrogenase(LDH) activity as well as total protein in the broncho-alveolar lavage fluid were determined. Broncho-alveolar lavage cells were also assayed for iNOS mRNA and the productions of nitrite and nitrate measured in the cells cultured. Differential analysis of broncho-alveolar lavage cells showed that the number of alveolar macrophages slightly decreased following silica treatment; however, red blood cells, lymphocytes, and neutrophils significantly were increased by 9-, 14-, and 119-fold following silica treatment, respectively, compared with the saline control. It was also found significant increases in the LDH activity and total protein in the lavage fluid obtained from silica-treated rats, indicating silica-induced acute lung injury. Northern blot analysis demonstrated that the steady state levels of iNOS mRNA in broncho-alveolar lavage cells were increased following silica treatment. The productions of nitrite and nitrate in the cultured cells were significantly increased by 2-fold following silica treatment, respectively, which were attenuated by the NOS inhibitor $N{\omega}-nitro-L-arginine-methyl$ ester(L-NAME) and partially reversed by L-arginine. These findings suggest that nitric oxide production in alveolar macrophages and recruited neutrophils is increased in response to silica. Nitric oxide may contribute in part to acute inflammatory lung injury.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.201-208
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• 1997

It is becoming increasingly clear that the inflammatory reaction can be ascribed to a complex array of mediators generated and released from activated phagocytes. In this study, the effect of PAF on interleukin-1(IL-1) activity by rat alveolar macrophages(AM) was examined using thymocyte proliferation assay in the supernate of sample obtained after 24 hr culture. When AM were cultured with PAF alone, no change in IL-1 activity was observed. However, the combined addition of PAF and muramyl dipeptide(MDP) or lipopolysaccharide(LPS) to AM cultures markedly enhanced IL-1 activity by 2-3 fold compared with AM cultures with the stimulant alone in a concentration dependent fashion. The peack effect was found at $10^{-8}$ M PAF with MDP and $10^{-14}$ M PAF with LPS. the effect of PAF was also tested in silica, toxic respirable dust, -added AM cultures as well as in the cultures containing bacterial compounds. Although silica did not stimulate the IL-1 activity, PAF could enhance IL-1 activity by 2 fold above the value of the silica-treated AM cultures with the peak response at $10^{-12}$ M PAF. Optimal enhancement of IL-1 activity occured when MDP and PAF were present together at the initiation of the 24 hr AM cultures. Additionaly, the biologically inactive precursor/metabolite of PAF, lyso-PAF failed to induce enhancement of IL-1 activity. When the specific, but structurally different PAF receptor antagonists, BN 52021($10^{-5}$ M) and CV 3988($10^{-5}$ M) was treated 15 min before addition of PAF($10^{-8}$ M) and MDP$(10\;{\mu}g/ml)$ to the AM cultures, it markedly inhibited the enhancement of IL-1 activity induced by PAF. The effects of these PAF antagonists were also observed in LPS$(10\;{\mu}g/ml)$-stimulated cells. Collectively, these data suggest that PAF enhances IL-1 activity by interaction with a specific receptor.

• Korean Journal of Plant Resources
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• v.24 no.3
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• pp.286-291
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• 2011

In this study we investigated effects of supplementation with ethyl acetate extracts of the brown alga Eisenia bicyclis on innate immune cells to evaluate the possibilities as an immunomoulator in exercise stress. Twenty male SD rats were divided into four groups and the treatments were as follows: A, no Eisenia bicyclis extract (EBE) (200 mg/kg) intake and maintained at rest ; B, no EBE intake and undergoing exercise ; C, EBE intake and undergoing exercise ; D, EBE intake and maintained at rest. After 5 weeks of oral supplementation, rats were undergoing intensive swimming exercises for 2 h and sacrificed to assess the effects on peritoneal macrophages, spleen cells and natural killer (NK) cells. We showed increasing effects on nitric oxide-inducible nitric oxide synthase (NO-iNOS) production by macrophages and no effects of NK tumoricidal activity and suppressive effects on spleen cell proliferation in exercise group. However, EBE supplementation suppressed NO-iNOS production by macrophages and increased NK tumoricidal activity and spleen cell proliferative response to mitogen in exercise group. Overall, these results that EBE supplementation has differential effects on innate immune response and could be useful as sports nutrition.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.20 no.1
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• pp.25-36
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• 1994

It is weal known that bacterial lipopolysaccharide (LPS) stimulates prostaglandin synthesis in various experimental system via enhancing the expression of cylooxygenase-2 (COX-2). This study was designed to characterize U)5-induced prostaglandin synthesis in mouse peritoneal macrophages LPS-stimulated prostaglandin synthesis in macrophages with short term exposure was not so much prominent, but there was a burst in prostaglandin synthesis 8 hours after the LPS treatment and this u·as accompanied with the increase of cyclooxygenase activity, Dexamethasone markedly inhibited prostaglandin synthesis in this system. Metabolic label ins data supported above observations and thus, it could be concluded that LPS induces the do novo synthesis of COX-2 by which it stimulates the prostaglandin synthesis in mouse peritoneal macrophages, These data suggested that this experimental model system could be used for the screening procedure of COX-2 selective inhibitors. Ketoprofen, a non steroidal anti inflammatory agent, appeared to inhibit COX-1 relatively more selectively than COX-2.