• The Journal of Internal Korean Medicine
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• v.30 no.2
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• pp.288-297
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• 2009

Objective : Inflammatory cytokines have a close relationship to insulin dependent diabetes mellitus (IDDM). The inhibitory effect of Smilacis Glabrae Rhizoma (SGR) were examined on production of nitric oxide (NO), prostaglandin $E_2$ $(PGE_2)$, synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and NF-${\kappa}$B activation in Raw 264.7 cells. Methods: Raw 264.7 cells were pretreated with SGR(20, 50, 100 ${\mu}g$/ml), and then cultured with lipopolysaccharides (LPS). Cell viability was measured by MTT assay; inhibition of NO, $PGE_2$, and TNF-${\alpha}$ production were measured by Griess reagent and enzyme-linked immunosorbent assay(ELISA). Induction of COX-2 and iNOS were determined by western blotting analysis. Inhibition of NF-${\kappa}$B was measured by immunofluorescence assay (IFA). Results: SGR inactivated NF-${\kappa}$B, and inhibited the production of NO, iNOS, and $PGE_2$. Inhibition of COX-2 and TNF-${\alpha}$ could not be confirmed. Conclusions: From the above result. SGR was found to have an anti-inflammatory effect of inhibition of NO, iNOS, and $PGE_2$ production via inhibition of NF-${\kappa}$B.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.215-221
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• 2005

We investigated the effects of testosterone and dihydrotestosterone on inflammatory response of iNOS and COX-2 expression in rat vascular smooth muscle cells. Rat vascular smooth muscle cells (VSMC) stimulated with bacterial lipopolysaccharide $(LPS;\;10{\mu}g/ml)$ for 24 hours were incubated with increasing amounts of testosterone and dihydrotestosterone (1 and 100 nM). LPS was found to induce inflammatory response of iNOS and COX-2 mRNA and protein in VSMC. These processes were affected by male sex steroid hormones. For 3 hours, however, pretreatment of the cells with 100 nM each of testosterone and dihydrotestosterone suppressed LPS induced iNOS and COX-2 protein expression. RT-PCR analysis revealed that testosterone and dihydrotestosterone did not inhibit mRNA expression of iNOS and COX-2 stimulated by 24 hours of LPS incubation. Proliferation rate was slower in VSMC treated with testosterone and dihydrotestosterone. Testosterone enhanced androgen receptor expression, and LPS significantly reduced androgen receptor protein expression in VSMC. These results indicate that the expression of both iNOS and COX-2 proteins was suppressed by testosterone and dihydrotestosterone in LPS stimulated VSMC and leading to reduction of vascular inflammation.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.3
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• pp.161-165
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• 2004

Exogenous carbon monoxide (0.2%) increases L-type calcium $(Ca^{2+})$ current in human jejunal circular smooth muscle cells. The stimulatory effect of carbon monoxide (CO) on L-type $Ca^{2+}$ current is inhibited by pre-application of L-NNA, a classical competitive inhibitor of nitric oxide synthase (NOS) with no significant isoform selectivity (Lim, 2003). In the present study, we investigated which isoform of NOS affected CO induced stimulation of L-type $Ca^{2+}$ current in human jejunal circular smooth muscle cells. Cells were voltage clamped by whole-cell mode patch clamp technique, and membrane currents were recorded with 10 mM barium as the charge carrier. Before the addition of CO, cells were pretreated with each inhibitor of three NOS isoforms for 15 minutes. CO-stimulating effect on L-type $Ca^{2+}$ current was partially blocked by N-(3-(Amino-methyl) benzyl) acetamidine 2HCl (1400W, an iNOS inhibitor). On the other hand, 3-bromo-7-nitroindazole (BNI, a nNOS inhibitor) or $N^5-(1-Iminoethyl)-L-ornithine$ dihydrochloride (L-NIO, an eNOS inhibitor) completely blocked the CO effect. These data suggest that low dose of exogenous CO may stimulate all NOS isoforms to increase L-type $Ca^{2+}$ channel through nitric oxide (NO) pathway in human jejunal circular smooth muscle cells.

• BMB Reports
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• v.54 no.10
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• pp.516-521
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• 2021

Although arginase primarily participates in the last reaction of the urea cycle, we have previously demonstrated that arginase II is an important cytosolic calcium regulator through spermine production in a p32-dependent manner. Here, we demonstrated that rhaponticin (RPT) is a novel medicinal-plant arginase inhibitor and investigated its mechanism of action on Ca²⁺-dependent endothelial nitric oxide synthase (eNOS) activation. RPT was uncompetitively inhibited for both arginases I and II prepared from mouse liver and kidney. It also inhibited arginase activity in both aorta and human umbilical vein endothelial cells (HUVECs). Using both microscope and FACS analyses, RPT treatments induced increases in cytosolic Ca²⁺ levels using Fluo-4 AM as a calcium indicator. Increased cytosolic Ca²⁺ elicited the phosphorylations of both CaMKII and eNOS Ser1177 in a time-dependent manner. RPT incubations also increased intracellular L-arginine (L-Arg) levels and activated the CaMKII/AMPK/Akt/eNOS signaling cascade in HUVECs. Treatment of L-Arg and ABH, arginase inhibitor, increased intracellular Ca²⁺ concentrations and activated CaMKII-dependent eNOS activation in ECs of WT mice, but, the effects were not observed in ECs of inositol triphosphate receptor type 1 knockout (IP3R1^-/-) mice. In the aortic endothelium of WT mice, RPT also augmented nitric oxide (NO) production and attenuated reactive oxygen species (ROS) generation. In a vascular tension assay using RPT-treated aortic tissue, cumulative vasorelaxant responses to acetylcholine (Ach) were enhanced, and phenylephrine (PE)-dependent vasoconstrictive responses were retarded, although sodium nitroprusside and KCl responses were not different. In this study, we present a novel mechanism for RPT, as an arginase inhibitor, to increase cytosolic Ca²⁺ concentration in a L-Arg-dependent manner and enhance endothelial function through eNOS activation.

• 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 Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.724-729
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• 2006

Many traditional herbal remedies exhibit several beneficial effects including anti-inflammation. The exact mechanism of the a-inflammato action of Panax notoginseng Buck F.H. Chen. however, has not been determined. In the present study, we have isolted the acting compound, emodin, from P. notoginseng and examined the effects of p. notoginseng and emodin on lipopolysaccharide (LPS)-induced nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expression in RAW264.7 macrophages. The results indicated that p. notoginseng concentration-dependently inhibited LPS-induced NO production. Furthermore, P. notoginseng inhibited the expression of LPS-induced iNOS and COX-2 proteins without an appreciable cytotoxic effect on RAW264.7 cells. Emodin also inhibited LPS-induced iNOS protein as potently as P. notoginseng. This was consistent with the findings that P. notoginseng but not emodin inhibited prostaglandin E2 synthesis induced Dy LPS.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1327-1333
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• 2006

Many traditional herbal remedies exhibit several beneficial effects including anti-inflammation. Panax notoginseng Buck F.H. Chen. is used as a therapeutic agent to stop haemorrhages and a tonic to promote health in Korean and Chinese medicine. The pharrnacokinetic profiles of the main P. notoginseng are still not accurately investigated. The exact mechanism of the anti-inflammatory action of P. notoginseng, however, has not been determined. In the present study, we examined the effect of P. notoginseng on lipopolysaccharide (LPS)-induced nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expression in RAW264.7 macrophages. The results indicated that P. notoginseng concentration-dependently inhibited LPS-induced NO production. Furthermore, P. notoginseng inhibited the expression of LPS-induced iNOS and COX-2 proteins without an appreciable cytotoxic effect on RAW264.7 cells. Berberine also inhibited LPS-induced iNOS protein as potently as P. notoginseng. This was consistent with the findings that P. notoginseng and also berberine inhibited prostaglandin E2 synthesis induced by LPS.

• Preventive Nutrition and Food Science
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• v.12 no.2
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• pp.74-78
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• 2007

Fucoidan, that is high-molecular-weight sulfated polysaccharides extracted from brown seaweeds has been shown to elicit various biological activities. Here, we investigated the effects of fucoidan on cell proliferation and nitric oxide (NO) production in neuronal blastoma cell (SH-SY5Y). In the present study, we demonstrated that fucoidan treatment resulted in increase of cell proliferation and NO production. When cells were treated with amyloid-${\beta}$ (A${\beta}$) in the absence or presence of fucoidan, fucoidan recovered the cell viability decreased by A${\beta}$ peptides. To further determine whether nitric oxide synthase (NOS) is involved in proliferative effect of fucoidan, cells were treated with NOS inhibitors in the absence or presence of fucoidan. Selective constitutive nitric oxide synthase (cNOS) inhibitor, diphenylene iodonium chloride (DPI), caused a decrease of cell viability, whereas cell viability was increased by specific inducible nitric oxide synthase (iNOS) inhibitor, S-methylisothiourea (SMT), in the fucoidan-untreated cells. Treatment with fucoidan inhibited the cell viability decreased in DPI-exposed cells. In contrast, fucoidan had no effect on cell growth in SMT-treated cells, indicating that cNOS may not play a role in the proliferation of fucoidan-treated cells. The present data suggest that fucoidan has proliferative and neuroprotective effects and these effects may be associated with iNOS.

• Journal of The Korean Association For Science Education
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• v.30 no.2
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• pp.249-260
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• 2010

The main purpose of this study is to examine the effects of explicit instructions on the nature of science (NOS) on the understanding of science-gifted students. Participants were engaged in 8 explicit NOS instructions spanning 6 months. Data were collected before and after the instructions from 20 science-gifted students using student worksheets, open-ended questionnaires (Views of Nature Of Science, VNOS), and in-depth interviews. The results of this study showed that explicit instructions were helpful in improving the understanding of the tentativeness in science and socially and culturally embedded aspects of science. However, participants not only still possess naive views on the nature of science about the distinction of law and theory and the empirical aspects of science, but also had conflicting views and misconceptions in some areas. The study has implication for development of science-gifted program that the explicit instructions on NOS and science inquiry should be provided concurrently, given the complementary relationship of the two activities.

• Journal of Science Education
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• v.44 no.3
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• pp.273-288
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• 2020

This study aims to investigate the presentation of the Nature of Science (NOS) in integrated science textbooks of the 2015 revised curriculum. The five integrated science textbooks published by the revised 2015 curriculum were analyzed with the conceptual framework of the four themes of the Nature of Science (NOS) (Lee, 2013) based on scientific literacy. The four themes of the NOS are 1. nature of scientific knowledge (theme I), 2. nature of scientific inquiry (theme II), 3. nature of scientific thinking (theme III), and 4. nature of interactions among science, technology, and society. The reliability of the textbooks analysis was measured between two coders by the Cohen's kappa and resulted in between 0,83 and 0,96, which means the results of analysis was consistent and reliable. The findings were as follows. First, overall theme II, nature of scientific inquiry emphasized on the integrated science textbooks of the 2015 revised curriculum by devoting the contents over 40 % in the all five publishing companies' textbooks. Second, while the theme II, nature of scientific inquiry was emphasized on the textbooks regardless of the publishing companies, other themes of the NOS were emphasized in different portions by the publishing companies. Thus, the focus among other three themes of the NOS was presented differently by the publishing companies except that in theme II, nature of scientific inquiry was most emphasized on integrated science textbooks. Third, the presentation of the NOS was identified similarly across the topics of integrated science textbooks except on topic 4. Environment and Energy. The theme IV, nature of interactions among science, technology, and society was emphasized reasonably only in the topic of Environment and Energy of the textbooks. Finally, the presentation of the NOS in the integrated science textbooks of the 2015 revised curriculum were more balanced among the four themes of the NOS with focus on the scientific inquiry compared to the previous curriculum textbooks.