• Biomedical Science Letters
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• v.19 no.3
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• pp.180-187
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• 2013

Hypoxia is an integral part of the environment during luteolysis. In this study we examined whether hypoxia could directly stimulate endothelial cells to produce nitric oxide (NO). Endothelial cells were cultured in hypoxic (5% $O_2$) or normoxic (20% $O_2$) conditions and the levels of total NO, inducible NO and endothelial NO was measured. We found that hypoxia but not normoxia upregulated NO production. The increased NO levels correlated with increased inducible NO synthase (iNOS) expression whereas expression of endothelial NOS (eNOS) expression remained constant. Addition of the iNOS specific inhibitor 1400W to hypoxic cultures prevented NO production suggesting that hypoxia-induced NO production in endothelial cells was due mainly to upregulation of iNOS. We also found that prostaglandin $F_{2{\alpha}}$ (PGF) production was unaffected by hypoxia suggesting that upregulation of NO was not due to increased synthesis of PGF. In summary, we report that endothelial cells cultured under hypoxic conditions produce NO via the iNOS pathway. This study provides the importance of the relation between the hypoxic environment and the induction of NO by endothelial cells during regression of the corpus luteum in the ovary.

• Journal of Acupuncture Research
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• v.27 no.3
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• pp.65-73
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• 2010

Objectives : Recently, Pharmacopuncture therapy has been used for the treatment of inflammatory diseases such as rheumatoid arthritis. Especially, we have been interested in chemical mediators concerned with inflammation such as prostaglandin, nitric oxide. The purpose of this study is investigated that the effect of Ampelopsis Radix Pharmacopuncture solution in RAW 264.7 macrophages, performed several experimental items : those are Prostaglandin $E_2$, Nitric Oxide and Cyclooxygenase-2. Methods : The cytotoxicity of Ampelopsis Radix Pharmacopuncture solution in RAW 264.7 macrophages were measured by MTT assay. In order to observe cyclooxygenase-2 mRNA expression in lipopolysaccharide and interferon-gamma stimulated RAW 264.7 macrophages, RT-PCR was used. Prostaglandin $E_2$ production and Nitric Oxide production was measured by nitric oxide detection kit and Prostaglandin $E_2$ assay kit. Results : 1. The MTT assay demonstrated that cytotoxic effect of Ampelopsis Radix Pharmacopuncture solution in RAW 264.7 macrophages was not appeared. 2. Ampelopsis Radix Pharmacopuncture solution inhibited nitric oxide production in lipopolysaccharide and interferon-gamma stimulated RAW 264.7 macrophages. 3. Ampelopsis Radix Pharmacopuncture solution inhibited cyclooxygenase-2 mRNA expression in lipopolysaccharide and interferon-gamma stimulated RAW 264.7 macrophages. 4. Ampelopsis Radix Pharmacopuncture solution inhibited Prostaglandin $E_2$ production in lipopolysaccharide and interferon-gamma stimulated RAW 264.7 macrophages. Conclusions : On the basis of these results, It was shown that Ampelopsis Radix Pharmacopuncture solution was able to inhibit the production of $PGE_2$ and NO, as well as COX-2 mRNA expression. Our results may provide new mechanism by which Ampelopsis Radix Pharmacopuncture solution accounts for its beneficial effect on accelerating wound healing and anti-inflammation.

• 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 Journal of Korean Medicine
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• v.26 no.4
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• pp.152-161
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• 2005

The excessive release of proinflammatory products by activated microglia causes neurotoxicity, and this has been implicated in the pathogenesis of neurodegenerative diseases. Harpagophytum procumbens (Pedaliaceae) has been widely used for the treatment of pain and arthritis in the clinical field. In this study, we investigated the effect of Harpagophytum procumbens against lipopolysaccharide-induced inflammation. From the present results, the aqueous extract of Harpagophytum procumbens was shown to suppress prostaglandin-E2 synthesis and nitric oxide production by inhibiting the lipopolysaccharide-stimulated enhancement of cyclooxygenase-2 and inducible nitric oxide synthase expressions in mouse BV2 microglial cells. These results suggest that Harpagophytum procumbens may offer a valuable means of therapy for the treatment of brain inflammatory diseases by attenuating lipopolysaccharide-induced prostaglandin-E2 synthesis and nitric oxide production.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.481-484
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• 1998

In activated macrophages the inducible form of nitric oxide synthase (i-NOS) generates high amounts of toxic mediator, nitric oxide (NO) which contributes to the circulatory failure associated with septic shock. A sesquiterpene lactone compound (yomogin) isolated from medicinal plant Artemisia princeps Pampan inhibited the production of NO in LPS-activated RAW 264.7 cells by suppressing i-NOS enzyme expression. Thus, yomogin may be a useful candidate for the development of new drugs to treat endotoxemia and inflammation accompanied by the overproduction of NO.

• Korean Journal of Acupuncture
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• v.28 no.1
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• pp.61-69
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• 2011

Objectives : The purpose of this study is to investigate effects of White Ginseng-Ejung-tang acupuncture solution (EJ) on nitric oxide (NO) and of hydrogen peroxide production in RAW 264.7 mouse macrophages stimulated by lipopolysaccharide (LPS). Methods : Cell viability was measured by modified MTT assay. NO production was measured by Griess reagent assay. Hydrogen peroxide production was measured by dihydrorhodamine 123 (DHR) assay. Significant differences were examined by using a Student's t-test. Results : The results of the experiment are as follows. 1. EJ did not show cell toxicity against RAW 264.7 cells for 24 hr incubation at the concentrations of up to $200\;{\mu}g$/mL in RAW 264.7 cells. 2. EJ significantly inhibited NO production for 24 hr incubation in RAW 264.7 cells (p <0.05). 3. EJ significantly inhibited the LPS-induced production of NO for 24 hr incubation in RAW 264.7 cells (p <0.05). 4. EJ significantly inhibited the LPS-induced production of hydrogen peroxide for 16, 24, 40, 48, 64, and 72 hr incubation in RAW 264.7 cells (p <0.05). Conclusions : These results suggest that EJ has an anti-inflammtory property related with its inhibition of NO and hydrogen peroxide production in LPS-induced macrophages.

• YAKHAK HOEJI
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• v.43 no.2
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• pp.198-207
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• 1999

The aim of the present investigation was to examine whether YH439, a hepatoprotective agent, exerts protective effect against hepatotoxicity and reduces the production of cytokines and NO in lipopolysaccharide (LPS)-primed rats with carbon tetrachloride ($CCl_4$). Administration of LPS following a single dose of CCl4 injection resulted in remarkable elevations of the serum $TNF{\alpha},{\;}IL-l{\beta$ and IL-6 level. The serum NO level was moderately elevated and severe liver damage was evidenced by increases in serum alanine aminotransferase (ALT) and sorbitol dehydrogenase (SDH) activities. YH439 decreased the levels of TNF, $IL-l{\beta}$, IL-6, ALT, SDH as well as NO in the serum elevated by CCl4+LPS in a dose-dependent manner. Inducible nitric oxide synthase (iNOS) level was decreased in the liver of rats treated with YH439. The increased iNOS activity induced by LPS and $interferon-{\gamma}$ was significantly decreased in RAW 264.7 cells by YH439 treatment. YH439 increased the GSH level decreased by $CCl_4+LPS$ and suppressed the ratio of GSSG/GSH. The reduction of hepatotoxicity by YH439 may associated with the decrease in the production of cytokines as well as suppression of iNOS protein in conjunction with an increase in the GSH level.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.156.2-157
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• 2003

Lipopolysaccharide (LPS)-stimulated macrophages produced a large amounts of nitric oxide (NO) by inducible nitric oxide synthase (iNOS). This is an important mechanism in macrophages-induced septic shock and inflammation. In the present study, we tested a synthetic propenone compound, l-furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) for its ability to inhibit the production of tumor necrosis factor-a (TNF-$\alpha$) and an inducible enzyme, iNOS, in the LPS-stimulated murine macrophage-like cell line, Raw264.7. FPP-3 consistently inhibited nitric oxide (NO) and TNF-$\alpha$ production in a dose dependent manner, with $IC_50$> values of 10.0 and 13.1 $\mu$M, respectively. (omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.313.1-313.1
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• 2002

Nitric oxide (NO) production through the inducible nitric-oxide synthase (iNOS) pathway has been implicated in inflammatory diseases and cellular injury. Inhibition of various genes related to inflammation, including iNOS is one of the major roles of well-known anti-inflammatory drugs. In the present study, the effects of ceramide analogs on iNOS expression and NO production were evaluated to investigate how ceramide and its structurally related analogs modulate NO-mecliated cellular signals and inflammation. (omitted)

• Journal of Integrative Natural Science
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• v.1 no.1
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• pp.41-46
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• 2008

The aim of this study is to evaluate the effects essential oil from Lavendular officinalis on the production of UVB-irradiated-induced nitric oxide(NO), in vivo and in vitro. NO is a recently discovered mediator of cell communication involved in a variety of physiological and pathophysiological processes. This enzyme is present in various tissues including smooth muscle cells and macrophages and take part in several immunopathological process. In vitro, the cytotoxicity and cell viability of aroma oil was evaluated by the MTT assay in the concentration of 0.01, 0.05, 0.1%. And, the effect of aroma oil was investigated to production of NO in human fibroblast cells line CCD-986sk ($2{\times}10^5$ cell/well) after UVB-irradiation with aroma oil (0.01, 0.1, and 1%). The result showed that aroma oil did not affected the production of NO. In vivo, it was investigated to production of NO after UVB- irradiation with aroma oil. The experimental groups were divided into four groups. Aroma oil was stimulated the production of NO by itself. As the results, all of the in vitro and in vivo, aroma oil were affected production of NO by dependent the concentration-manners.