• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.282-287
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• 2014

We show that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibits cytokine mixture (CM: TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$)-induced production of nitric oxide (NO) in the pancreatic beta cell line MIN6N8a. Immunostaining and Western blot analysis showed that silymarin inhibits iNOS gene expression. RT-PCR showed that silymarin inhibits iNOS gene expression in a dose-dependent manner. We also showed that silymarin inhibits extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) phosphorylation. A MEK1 inhibitor abrogated CM-induced nitrite production, similar to silymarin. Treatment of MIN6N8a cells with silymarin also inhibited CM-stimulated activation of NF-${\kappa}B$, which is important for iNOS transcription. Collectively, we demonstrate that silymarin inhibits NO production in pancreatic beta cells, and silymarin may represent a useful anti-diabetic agent.

• Biomedical Science Letters
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• v.25 no.3
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• pp.267-274
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• 2019

Toll-like receptors (TLRs) are one of the families of pattern recognition receptors (PRR) to recognize pathogen-associated molecular patterns (PAMPs). PAMPs stimulate TLRs to initiate specific immunoactivity. The activation of TLRs signaling leads to the expression of pro-inflammatory gene products such as cytokines and inducible nitric oxide synthase (iNOS). To evaluate the therapeutic potential of dehydrocostus lactone (DHL), which is a natural sesquiterpene lactone derived from various medicinal plants, iNOS expression induced by LPS (TLR4 agonist), MALP-2 (TLR2 and TLR6 agonist), or Poly[I:C] (TLR3 agonist) were examined. DHL suppressed the iNOS expression induced by LPS, MALP-2, or Poly[I:C]. DHL also inhibited nitrite production induced by LPS, MALP-2, or Poly[I:C]. These results suggest that DHL can modulate TLRs signaling pathways resulting in anti-inflammatory effect.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.311-318
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• 2003

Eurya emarginata (Thunb.) Makino (Theaceae) is distributed in coastal areas of island. The leaves of Eurya are used in the traditional medicine of the coastal areas of jeju island with the aim of diuresis or to treat ulcers. Nevertheless, there are few reports on the biological activity and constituents of E. emarginata. In this study, we investigated the pharmacological activity of the solvent extracts of E. emarginata on the several inflammatory markers (TNF-$\alpha$, IL-1$\beta$, IL-6, NO, iNOS and COX-2). Also we examined the antioxidizing effect of the solvent extracts by determination of DPPH radical-scavenging activity. Among the solvent fractions, EtOAc and BuOH extracts showed potent radical scavenging activity (RC$_{50}$=10.9 and 12.7 respectively). The subtractions of EF 5-4-6-3-2 and BF 1 potentially inhibited the mRNA expression of pro-inflammatory cytokines (IL-1$\beta$, IL-6 and TNF-$\alpha$) at the concentration of 100 $\mu\textrm{g}$/mι. Also the fractions inhibited the mRNA expression of pro-inflammatory cytokines (IL-1$\beta$, IL-6 and TNF-$\alpha$) and protein expression of iNOS and COX-2 at the concentration of 100 $\mu\textrm{g}$/mι. And then, the inhibition of iNOS was correlated with the decrease of nitrite level. These results suggest that E. emarginata may have anti-inflammatory activity through the inhibition of pro-inflammatory cytokines, iNOS and COX-2.2.

• Journal of Life Science
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• v.24 no.2
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• pp.181-185
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• 2014

We identified SNPs (single nucleotide polymorphisms) for endothelial nitric oxide synthase (eNOS) genes in the Korean genome. eNOS is present in the vascular endothelium, platelets, and several other cell types that continuously produce modest amounts of NO. Endothelium-derived NO plays a key role in the regulation of vascular tone, and the impaired effects of NO on the cardiovascular system appear to be responsible for coronary atherosclerosis and thrombosis. In recent studies, a missense variant within exon 7 of the eNOS gene in patients with coronary spastic angina-GAG to GAT substitution, which results in the replacement of glutamic acid by aspartic acid (Glu298Asp [G894T])-has been identified and is known to be significantly associated with coronary spasm. We prepared PCR primers based on sequences in Genbank. Primers were prepared for normal and SNPs separately, as reported for other Asian countries, such as G894T. Their sequences were different only at the 3' ends so that primer extension could only by possible when base pairs between templates and primers matched. We also employed ARMS (Amplification Refractory Mutation System) technology to improve the specificity of the PCR reaction. In conclusion, we were able to demonstrate the eNOS G894A polymorphism in Korean gemone. This study should facilitate research on the cause of myocardial infarction and development on further therapy at the genetic level.

• Journal of Gifted/Talented Education
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• v.21 no.2
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• pp.391-405
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• 2011

The nature of science has been recognized in a great deal in the field of science education. However, only few innovative programs are offered for science-gifted students to improve their recognition of the nature of science. The current study describes and analyzes science-gifted students' understandings of the nature of science (NOS). In addition, the study looks into contradictory views among the aspects of NOS, which are fundamental data in constructing target programs on NOS for science gifted students. Data used in this study were collected from 73 middle school science-gifted students using an open-ended questionnaire, VNOS. The results of this study showed that the participants' understanding of NOS was significantly distributed on naive or transition view except for 'tentative NOS', and the results revealed inconsistent view among the aspects of NOS. This study proposes two suggestions to enhance the recognition of science-gifted on NOS of science to informed state and to have consistent perspectives with other areas. First, the role of experiment has to be changed-it should be the process in constructing scientific knowledge rather than an instrument to check scientific knowledge to transform perspective on experimental data and scientific knowledge. Second, various opportunities must be provided to science-gifted students, so they can experience the culture and community of scientists and science to gain a wider insight of science.

• Journal of Life Science
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• v.13 no.4
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• pp.441-447
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• 2003

To examine the role of protein kinase C (PKC) in regulation of interleukin-1 beta (IL-1$\beta$)-induced iNOS expression, IL-1$\beta$-induced nitrite production was observed in cultured vascular smooth muscle (VSM) cells pretreated with phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-butyrate (PDB) as PKC activator; 4$\alpha$-phorbol-didecanoate (PDD) as PKC non-activator. Nitrite production induced by IL-1$\beta$ was increased by the presence of increasing concentration of PMA ranging from 2 to 200 nM. However, in VSM cells pretreated with PMA and PDB, IL-1$\beta$-induced $NO_2$ production was decreased in proportion to the duration of pretreatment, and most significantly decreased in pretreatment time of 24 hours. Using RT-PCR method, the expression of iNOS mRNA induced by IL-1$\beta$ was decreased in VSM cells pretreated with PMA 200 nM for 24 hours. These results suggest that decrease in IL-I$\beta$-induced nitrite production by the pretreatment of PMA result from inhibition of iNOS expression and the inhibition related to PMA-induced PKC down-regulation.

• IMMUNE NETWORK
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• v.9 no.5
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• pp.192-202
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• 2009

Background: Little information is available the role of Nitric Oxide (NO) in host defenses during human tuberculosis (TB) infection. We investigated the modulating factor(s) affecting NO synthase (iNOS) induction in human macrophages. Methods: Both iNOS mRNA and protein that regulate the growth of mycobacteria were determined using reverase transcriptase-polymerase chain reaction and western blot analysis. The upstream signaling pathways were further investigated using iNOS specific inhibitors. Results: Here we show that combined treatment with 1,25-dihydroxyvitamin D3 (1,25-D3) and Interferon (IFN)-${\gamma}$ synergistically enhanced NO synthesis and iNOS expression induced by Mycobacterium tuberculosis (MTB) or by its purified protein derivatives in human monocyte-derived macrophages. Both the nuclear factor-${\kappa}B$ and MEK1-ERK1/2 pathways were indispensable in the induction of iNOS expression, as shown in toll like receptor 2 stimulation. Further, the combined treatment with 1,25-D3 and IFN-${\gamma}$ was more potent than either agent alone in the inhibition of intracellular MTB growth. Notably, this enhanced effect was not explained by increased expression of cathelicidin, a known antimycobacterial effector of 1,25-D3. Conclusion: These data support a key role of NO in host defenses against TB and identify novel modulating factors for iNOS induction in human macrophages.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.3
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• pp.165-172
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• 2005

The aim of this study was to determine the roles of ET-1 and NO on uterine blood flow in pregnancy. Uterine arteries were isolated from 17 nonpregnant and 12 pregnant women. Nonpregnant group included patients with median age of $48.6{\pm}2.3$ years who underwent hysterectomy, because of myoma. Pregnant group included patients with median age of $31.3{\pm}1.4$ years undergoing cesarean delivery. ET-1 and ET-2 induced concentration-dependent contraction in isolated nonpregnant and pregnant uterine arteries. The contractile response and maximal contraction were increased in pregnant uterine arteries. In nonpregnant uterine arteries, there was no contraction in response to ET-3, whereas pregnancy induced concentration-dependent contraction by ET-3. Tissue nitrite/nitrate level and immunohistochemical staining of eNOS and iNOS were increased in pregnant uterine arteries, compared with nonpregnant uterine arteries. In addition, the expressions of eNOS and iNOS mRNA were significantly increased in pregnancy. Moreover, contractions by ET isopeptides, including ET-1, were enhanced, and immunohistochemical staining of ET-1 and ET-1 mRNA expression was increased in pregnant uterine arteries. These results suggest that NO production by increased NOS activity, especially eNOS activity, is related to placental and uterine blood flow. Furthermore, ET-1 appears to play a pathophysiological role in pregnant complications such as hypertension.

• Korean Journal of Acupuncture
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• v.21 no.1
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• pp.15-27
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• 2004

Objectives : Acupuncture has been used to prevent and treat the cerebrovascular accident, such as a stroke, and many studies of acupuncture and moxibustion concerning to the stroke have been undertaken in the human and various animals. Also, herbal acupuncture, namely aqua acupuncture has been applied and developed to various diseases including the cerebrovascular accident. FOLIUM ARTEMISIAE ARGYI is the dry leaf of Artemisia argyi Levl. et Vant. collected in summer before the plant blooms and used to moxibustion and has been recommended for use as an analgesic and hemostatic. In this study, effects of FOLIUM ARTEMISIAE ARGYI (艾葉)' herbal acupuncture on the $LR_3$, namely Taechung on neuroprotection after the transient forebrain ischemia were investigated in Sprague-Dawely rats. Methods : Expressions of neuronal nitric oxide synthase (nNOS) protein in the hippocampus and cortex were observed at 2 hrs after transient forebrain ischemia by immunohistochemistry. Results : Expression of nNOS protein was increased in the hippocampus and cortex at 2 hrs after transient forebrain ischemia. However, pretreatment with FOLIUM ARTEMISIAE ARGYI' herbal acupuncture on $LR_3$ significantly decreased expression of nNOS protein protein compared to ischemia group. These features were observed in the motor cortex and the hippocampus. Conclusions : These results suggest that pretreatment with FOLIUM ARTEMISIAE ARGYI' herbal acupuncture on $LR_3$ inhibits the expression of nNOS protein induced by transient forebrain ischemia and may modulate excitatory toxicity of neuron related to neuronal cell death.

• Journal of Trauma and Injury
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• v.21 no.2
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• pp.120-127
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• 2008

Purpose: Many studies on the time course of inducible nitric oxide synthase (iNOS) gene expression have been performed in the LPS (Lipopolysaccharide)-induced endotoxemic model, but there have been few experimental approaches to continuous peritonitis-induced sepsis model. We conducted this study to establish basic data for future sepsis-related research by investigating the time course of iNOS gene expression and the relationship with the production of inflammatory mediators in the early sepsis model induced by cecal ligation and puncture (CLP). Methods: Male Sprague-Dawley rats were operated on by sing the CLP method to induce of peritonitis; and then, they were sacrificed and samples of blood and lung tissues were obtained at various times (1,2,3,6,9 and 12 h after CLP). We observed the expression of iNOS mRNA from lung tissues and measured the synthesis of nitric oxide, $IL-1{\beta}$, and $TNF-{\alpha}$ from the blood. Results: iNOS mRNA began to be expressed at 3 h and was maintained untill 12 h after CLP. The nitric oxide concentration was increased significantly at 6 h, reached its peak level at 9 h, and maintained a plateau untill 12 h after CLP. $TNF-{\alpha}$ began to be detected at 3 h, increased gradually, and decreased steeply from 9 h after CLP. $IL-1{\beta}$ showed its peak level at 6 h after CLP, and tended to decrease without significance. Conclusion: We observed that the iNOS gene was expressed later in peritonitis-induced sepsis than in LPS-induced sepsis. Nitric oxide and key inflammatory mediators were also expressed later in peritonitis-induced sepsis than in LPS-induced sepsis.