• Journal of Life Science
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• v.16 no.2 s.75
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• pp.192-198
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• 2006

Epidemiological studies have demonstrated an association between exposure to diesel exhaust particles (DEP) and adverse cardiopulmonary effects. Despite the epidemiological proof, the pathogenesis of DEP-related pulmonary diseases remain poorly understood. So, comprehensive in vivo and in vitro researches are required to know the effects of DEP on diverse lung diseases. Alveolar macrophages (AM) and airway epithelial cells are known as important cellular targets in DEP-induced lung diseases. Other studies have shown that nitric oxide (NO) is involved in particle matter induced lung injury. The present study was undertaken to determine whether DEP has an synergistic effects on lipopolysaccharide (LPS)-induced NO formation and inducible nitric oxide synthase (iNOS) with nitrotyrosilated-protein formation in cultured primary alveolar macrophages. The formation of NO was determined through the Griess reaction in the cultured medium and iNOS with nitrotyrosilated-proteins are analyzed by immunohistochemical staining and Western analysis. The results indicate that DEP exposure does not induce NO formation by itself, however DEP showed significant synergistic effects on LPS-induced NO formation. So, our results suggest that DEP inhalation could aggravate inflammatory lung disease through NO formation.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.673-679
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• 1997

It has been generally accepted that glutamate mediates the ischemic brain damage, excitotoxicity, and induces release of neurotransmitters, including norepinephrine(NE), in ischemic milieu. In the present study, the role of nitric oxide(NO) in the ischemia-induced $[^3H]norepinephrine([^3H]NE)$ release from cortex slices of the rat was examined. Ischemia, deprivation of oxygen and glucose from $Mg^{2+}-free$ artificial cerebrospinal fluid, induced significant release of $[^3H]NE$ from cortex slices. This ischemia-induced $[^3H]NE$ release was significantly attenuated by glutamatergic neurotransmission modifiers. $N^G-nitro-L-arginine$ methyl ester(L-NAME), $N^G-monomethyl-L-arginine$ (L-NMMA) or 7-nitroindazole, nitric oxide synthase inhibitors attenuated the ischemia-evoked $[^3H]NE$ release. Hemoglobin, a NO chelator, and 5, 5- dimethyl-L-pyrroline-N-oxide(DMPO), an electron spin trap, inhibited $[^3H]NE$ release dose-dependently. Ischemia-evoked $[^3H]NE$ release was inhibited by methylene blue, a soluble guanylate cyclase inhibitor, and potentiated by 8-bromo-cGMP, a cell permeable cGMP analog, zaprinast, a cGMP phosphodiesterase inhibitor, and S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide generator. These results suggest that the ischemia-evoked $[^3H]NE$ release is mediated by NMDA receptors, and activation of NO system is involved.

• Journal of Photoscience
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• v.9 no.2
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• pp.205-208
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• 2002

Nitric oxide (NO) is a newly described transmitter involved with cell to cell communication that is generated in biologic tissues by specific types of nitric oxide synthase (NOS), which metabolize L-arginine and molecular oxygen to citrulline and nitric oxide. In the skin. NO has been reported to play an important role in such diseases as psoriasis, atopic dermatitis, and contact dermatitis, as well as act as an important modulator in UVB-induced erythema. Ultraviolet B irradiation to the skin evokes an increase in NO production in the epidermis through two pathways; induction of inducible NOS, mediated by inflammatory cytokines, and elevation of constitutive neuronal NOS activity. In a cell culture system, it has been demonstrated that NO functions as a melanogen after being produced in keratinocytes in response to UVB-irradiation. NO-stimulated melanogenesis in melanocytes is mediated by the cGMP/PKG pathway. In this study, up-regulation of tyrosinase gene expression by NO-stimulation and the involvement of NO in UVB-induced pigmentation were examined. In NO-induced melanogenesis, protein synthesis and tyrosinase activity increased along with an up-regulation of tyrosinase gene expression. In an animal model, UVB-induced pigmentation in skin was suppressed by sequential daily treatments with a specific inhibitor of NOS. Thus, NO plays an important role in UVB-induced pigmentation, where its function as a melanogen is considered to be one of the mechanisms. Together with its role in the development of erythema, NO contributes to the total protective response of skin against UVB-irradiation.

• Development and Reproduction
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• v.1 no.2
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• pp.157-164
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• 1997

To study the regulation of porcine follicular cell apostosis by gonadotropin, steroid, and nitric oxide, we analyzed DNA fragmentation, the hallmark of apoptosis, and nitrite production of porcine granulosa cells. Dissected indiidual follicles from ovary were separated in size (small, 2-3 mm; medium, 5-6 mm; large, 7-8 mm) and isolated granulosa cells were classified morpholocally as atretic or nonatretic. Nitrite concentration was measured by mixing follicular fluids with an equal volume of Griess reagent. Follicular nitric oxide (NO) concentration of healthy follicles was higher than that of atretic follicles. Apoptotic DNA fragmentation was suppressed in non-apoptotic granulosa cells. Follicular apoptosis was induced by androgen but prevented by gonadotropin in vitro. Apoptosis was confined to the granulosa cells. But it was not clear whether apoptosis of granulosa cells were isolated, incubated with or without gonadotropin, androgen and sodium nitroprusside (SNP), respectively at $37^{\circ}C$ for 24 hrs. Cultured granulosa cells were used to extract genomic DNA and culture media was asssayed for nitrite concentration. Nitrite production of culture media was increased, while apoptotic DNA fragmentation was suppressed in PMSG, hCG, testosterone+SNP and SNP treated groups. Nitrite concentration in culture media was decreased, but apoptotic DNA fragmentation was induced in testosterone treated group. These data suggest that NO production and apoptosis may be involved of granulosa cell apoptosis induced by testosterone.

• Natural Product Sciences
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• v.23 no.2
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• pp.92-96
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• 2017

A sesquiterpene was purified from Artemisia iwayomogi methanolic extract during the course of searching anti-inflammatory principle from medicinal plants. A sesquiterpene identified as armefolin inhibited the production of nitric oxide (NO) and attenuated inducible nitric oxide synthase (iNOS) protein level in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Armefolin also down-regulated mRNA expressions of iNOS and pro-inflammatory cytokines, interleukin-$1{\beta}$ and interleukin-6 in LPS-activated macrophages. Moreover, armefolin suppressed the degradation of inhibitory-${\kappa}B{\alpha}$ (I-${\kappa}B{\alpha}$) in LPS-activated macrophages. These data suggest that armefolin from A. iwayomogi can suppress the LPS-induced production of NO and the expression of iNOS gene through inhibiting the degradation of I-${\kappa}B{\alpha}$. Taken together, armefolin from A. iwayomogi might be a candidate as promising anti-inflammatory agent.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.368-372
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• 2011

In this study, we investigated on antioxidative activity and nitric oxide production inhibitory activity of various solvent extracts of Lespedeza bicolor. The total polyphenol content of the methanol extract was 192.6 mg/g and flavonoid content of the acetone extract was 40.6 mg/g, as the highest content. In DPPH radical scavenging ability, $SC_{50}$ values of the ethanol and methanol extract were exhibited $0.69mg/m{\ell}$ and $0.89mg/m{\ell}$, respectively. However, in nitric oxide(NO) scavenging ability, $SC_{50}$ values of the acetone was exhibited $0.72mg/m{\ell}$ as the highest activity. Moreover, the acetone extract showed strong NO production inhibitory effect in lipopolysaccharide(LPS)-stimulated Raw 264.7 cell. In the cytotoxicity measurement by MTT assay, the extracts were exhibited Raw 264.7 cell viabilities of 92.57~129.04% as nontoxic result in concentration of $65{\sim}650{\mu}g/m{\ell}$. As a result, the acetone extract of L. bicolor could be applicable to functional materials for anti-inflammatory related fields.

• Journal of Ginseng Research
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• v.37 no.1
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• pp.64-73
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• 2013

Korean red ginseng water extract (KG-WE) has known beneficial effects on the cardiovascular system via inducting nitric oxide (NO) production in endothelium. Endothelial arginase inhibits the activity of endothelial nitric oxide synthase (eNOS) by substrate depletion, thereby reducing NO bioavailability and contributing to vascular diseases including hypertension, aging, and atherosclerosis. In the present study, we demonstrate that KG-WE inhibits arginase activity and negatively regulates NO production and reactive oxygen species generation in endothelium. This is associated with increased dimerization of eNOS without affecting the protein expression levels of either arginase or eNOS. In a vascular tension assay, when aortas isolated from wild type mice were incubated with KG-WE, NO-dependent enhanced vasorelaxation was observed. Furthermore, KG-WE administered via by drinking water to atherogenic model mice being fed high cholesterol diet improved impaired vascular function. Taken together, these results suggest that KG-WE may exert vasoprotective effects through augmentation of NO signaling by inhibiting arginase. Therefore, KG-WE may be useful in the treatment of vascular diseases derived from endothelial dysfunction, such as atherosclerosis.

• The Korea Journal of Herbology
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• v.21 no.2
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• pp.165-173
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• 2006

Objectives : Coptidis Rhizoma has been known traditional medicine with antimicrobial activities. We investigated inhibitory effects of Coptidis Rhizoma extract on lipopolysaccharide(LPS)-induced nitric oxide production from mouse macrophages. Methods : After Coptidis Rhizoma extract was pretreated in BV2, mouse brain macrophages and RAW264.7 mouse macrophages, cells were activated with LPS. To investigate cytotoxicity Coptidis Rhizoma extract, cell viability was measured by MTT assay. The production of nitric oxide(NO) and inducible nitric oxide synthase(iNOS) was determined in each culture supernatant and mRNA by Griess reaction and RT-PCR. The production of $TNF-{\alpha}$ from cells was measured by ELISA. Results : Coptidis Rhizoma extract significantly inhibited LPS-induced NO production in BV2 and RAW264.7 cells. Coptidis Rhizoma extract also greatly suppressed mRNA expression of iNOS in BV2 and RAW264.7 cells activated by LPS. Conclusion : These data suggests that Coptidis Rhizoma extract may have an anti-inflammatory effect through the inhibition of NO production.

• 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.

• Biomolecules & Therapeutics
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• v.9 no.3
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• pp.183-187
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• 2001

Nitric oxide (NO) produced in large amounts by the inducible nitric oxide synthase (iNOS) is known to be responsible for the vasodilation and hypotension observed in septic shock and inflammation. The inhibitors of iNOS, thus, may be useful candidate for the treatment of inflammatory diseases accompanied by the overproduction of NO. We prepared alcoholic extracts of Chinese medicinal plants and screened their inhibitory activity against NO production in lipopolysaccharide (LPS)-activated macrophages. Among the 80 kinds of extracts of herbal drugs, 15 extracts showed potent inhibitory activity of NO production above 80% at the concentration o$50\mu\textrm{g}/ml$. These potent extracts showed dose dependent inhibition of NO production of LPS-activated macrophages at the concentration of 50, 30,$10\mu\textrm{g}/ml$. Especially, Rhus chinensis, Senecio scandens and Wikstroemia indica showed most potent inhibition above 50% at the concentration of $10\mu\textrm{g}/ml$. These plants are promising candidates for the study of the activity-guided purification of active compounds and would be useful for the treatment of inflammatory diseases and endotoxemia accompanying the overproduction of NO.