• 대한의생명과학회지
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• 제24권2호
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• pp.102-107
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• 2018

Toll-like receptors (TLRs) play an important role for host defense against invading pathogens. The activation of TLRs signaling leads to the activation of $NF-{\kappa}B$ and the expression of pro-inflammatory gene products such as cytokines and inducible nitric oxide synthase (iNOS). To evaluate the therapeutic potential of cardamonin, which is a naturally occurring chalcone from Alpinia species (zingiberaceous plant species), $NF-{\kappa}B$ activation and iNOS expression induced by MALP-2 (TLR2 and TLR6 agonist) or LPS (TLR4 agonist) were examined. Cardamonin inhibited the activation of $NF-{\kappa}B$ induced by MALP-2 or LPS. Cardamonin also suppressed the iNOS expression induced by MALP-2 or LPS. These results suggest that cardamonin has the specific mechanism for anti-inflammatory responses by regulating of TLRs signaling pathway.

• 대한의생명과학회지
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• 제23권2호
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• pp.104-110
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• 2017

Inflammation is a pathophysiological process that is known to be involved in numerous diseases. Microbial infection or tissue injury activates inflammatory responses, resulting in the induction of proinflammatory proteins including inducible nitric oxide synthase (iNOS). Aster yomena is used in traditional Korean remedies. Here, we investigated the effects of ethanol extracts of Aster yomena (EAY) on the expression of iNOS induced by ovalbumin (OVA), one of the major egg allergens, or lipopolysaccharide (LPS), a Toll-like receptor 4 agonist. EAY inhibited OVA- or LPS-induced $NF-{\kappa}B$ activation. EAY also suppressed OVA- or LPS-induced iNOS expression and nitrite production. These results suggest that EAY has the specific mechanism for anti-inflammatory responses and the potential to be developed as a potent anti-inflammatory and anti-allergic drug.

• 대한의생명과학회지
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• 제29권2호
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• pp.66-74
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• 2023

Triglyceride (TG) accumulation can cause monocytic death and suppress innate immunity. However, the signaling pathways involved in this phenomenon are not fully understood. This study aimed to examine whether inducible nitric oxide synthase (iNOS) is involved in the TG-induced death of THP-1 monocytes. Results showed that iNOS was upregulated in TG-treated THP-1 monocytes, and iNOS inhibition blocked TG-induced monocytic death. In addition, TG-induced poly (ADP-ribose) polymerase (PARP) cleavage and caspase-3 and -7 activation were suppressed by iNOS inhibition. Furthermore, the expression of X-linked inhibitor of apoptosis protein (XIAP) and survivin, which inhibit caspase-3 and -7, was reduced in TG-treated THP-1 monocytes, but iNOS inhibition recovered the TG-induced downregulation of XIAP and survivin expression. Considering that TG-induced monocytic death is triggered by caspase2 and -8, we investigated whether caspase-2 and -8 are linked to the TG-induced expression of iNOS in THP-1 monocytes. When the activities of caspase-2 and -8 were inhibited by specific inhibitors, the TG-induced upregulation of iNOS and downregulation of XIAP and survivin were restored in THP-1 monocytes. These results suggest that TG-induced monocytic death is mediated by the caspase-2/caspase-8/iNOS/XIAP and survivin/executioner caspase/PARP pathways.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 춘계학술대회 논문집
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• pp.50-50
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• 2003

Nitric oxide (NO) has been studied and found to be an important intracellular modulator. The excess NO produced by the inducible nitric-oxide synthase (iNOS) is implicated in various inflammatory diseases and cellular injury. Inflammatory cytokines such as TNF- or IL-6 increase intracellular ceramide and ceramide may induce NO production and inflammation. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.293.2-293.2
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• 2002

Bisphenol A ［BPA. 2.2-bis(4-hydroxyphenyl)propane］ is reported to have estrogenic activity: however. its influence on cytokine production or immune system function remains unclear. In this study. we investigated the effects of BPA on the production of nitric oxide (NO) and tumor necrosis factor-a (TNF-a), and on the level of inducible nitric oxide synthase (iNOS) and TNF-a gene expression in mouse macrophages. BPA alone did not affect NO or TNF-a production. (omitted)

• 약학회지
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• 제43권2호
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• pp.214-220
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• 1999

Present study was aimed to examine whether indomethacin affected the production of NO in the rat paw exudate by carrageenin. Paw edema and nitrite/nitrate levels in the paw exudate were maximal after 4 h and remained elevated up to 10 h, whereas indomethacin (10 mg/kg, po) significantly inhibited the carrageenin-induced paw edema and levels of nitrate in the paw exudate. However, paw edema and nitrite/nitrite levels were increased thereafter for 10 h. Indomethacin also enhanced the expression of iNOS mRNA and protein 4 h after carrageenin infection. Indomethacin inhibited the level of $PGE_2$ in the paw exudate in a time-dependent manner. These results suggest the possibility that indomethacin may potentiate expression of iNOS and subsequently increase nitrite/nitrate level in the late phase of carrageenin-induced rat paw inflammation possibly by suppressing cycloxygenase activity.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E2호
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• pp.121-128
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• 2002

This study was carried out to investigate if nitric oxide synthase (NOS) inhibitors modulate airway inflammation induced by diesel exhaust particles (DEP). N$\^$G/-nitro-L-arginine methyl ester (L-NAME), a potent constitutive NOS (cNOS) inhibitor, and aminoguanidine (AG), a selective inducible NOS (iNOS) inhibitor, were administered to mice in their drinking water for 7 weeks. Airway inflammation was elicited by the repeated intratracheal administration of DEP. The results showed that macrophages, inflammatory eosinophils and neutrophils in bronchoalveolar lavage (BAL) fluids by intratracheal DEP instillation were significantly suppressed in the mice treated with two NOS inhibitors toghther with DEP. The suppression of these cells was more effective in AG treated groups than in L -NAME treated groups. NOS inhibitor treatment also reduced interleukin -5 (IL-5 in the BAL fluids and lung homogenates. Additionally, it was found that eosinophil peroxidase (EPO) activity in the BAL fluids was also decreased by NOS inhibitor treatment. These results suggest that nitric oxide (NO) is produced in airway inflammation by repeated DEP instillation, and that iNOS inhibition as well as cNOS inhibition can play a modulating role in this airway inflammation by DEP.

• 생명과학회지
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• 제16권2호
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• pp.192-198
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• 2006

본 연구에서는 DEP의 노출이 새로운 호흡기계 질환 유발의 가능성과 호흡기계의 염증성인자로 잘 알려진 lipopolysaccharide (LPS)의 역할에 어떠한 영향을 미치는 지를 확인하고자 폐에서 염증성 반응 시 생성이 증가하는 것으로 알려진 Nitric Oxide (NO)의 형성과 NO의 생성에 관련된 효소인 inducible nitric oxide synthase (iNOS) 및 NO에 의하여 형성되는 것으로 알려진 nitrotyrosilated-protein을 폐포 대식세포를 통해 분석하였다. 폐포대식세포에 DEP를 농도 별로 단독 처리하였을 때와 동일한 농도에서 배양시간을 달리하였을 때는 NO가 생성되지 않았으나 DEP와 함께 LPS를 처리하였을 때는 LPS를 단독으로 처리했을 때보다. 유의성이 있게 증가함을 확인할 수 있었다. 또한 NO의 생성에 관련된 효소인 iNOS 및 NO에 의하여 형성되는 것으로 알려진 nitrotyrosilated-protein 발현의 정도를 면역화학염색과 Western analysis로 확인할 수 있었다. DEP는 폐포대식세포에서 직접적으로 NO생성에 영향을 미치지 않았으며, NO를 생성하는 iNOS나 nitrotyrosilated-protein의 발현에도 영향을 주지 않았으나 세균성 염증인자의 한 종류인 LPS가 NO를 형성하는 데에는 통계학적인 상승효과가 있었다. 결론적으로 본 연구에서는 염증성질환의 환자에서 DEP의 흡입은 간접적으로 NO를 형성하는데 영향을 미쳐 질환을 악화시킬 것으로 판단한다.

• The Korean Journal of Physiology and Pharmacology
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• 제10권6호
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• pp.337-341
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• 2006

The present study was designed to investigate the protein expression of nitric oxide synthase (NOS) and guanylyl cyclase (GC) activity in ischemia/perfusion (I/R) renal injury in rats. Renal I/R injury was experimentally induced by clamping the both renal pedicle for 40 min in Sprague-Dawley male rats. The renal expression of NOS isoforms was determined by Western blot analysis, and the activity of guanylyl cyclase was determined by the amount of guanosine 3', 5'-cyclic monophosphate (cGMP) formed in response to sodium nitroprusside (SNP), NO donor. I/R injury resulted in renal failure associated with decreased urine osmolality. The expression of inducible NOS (iNOS) was increased in I/R injury rats compared with controls, while endothelial NOS (eNOS) and neuronal NOS (nNOS) expression was decreased. The urinary excretion of NO metabolites was decreased in I/R injury rats. The cGMP production provoked by SNP was decreased in the papilla, but not in glomerulus. These results indicate an altered regulation of NOS expression and guanylyl cyclase activity in I/R-induced nephropathy.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.626-631
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• 2005

Nitric oxide (NO) derived from inducible nitric oxide synthase (iNOS) is involved in cell apoptosis, which contributes to luteal regression and luteolysis in some species. In large domestic animals, no direct evidence for the relationship between NO and cell apoptosis in the process of corpus luteum regression is reported. The present study was conducted to investigate the localization of iNOS on porcine corpora lutea (CL) during the oestrus cycle and its relation to cell DNA fragmentation and CL regression. According to morphology, four luteal phases throughout the estrous cycle were defined as CL1, CL2, CL3 and CL4. By isoform-specific antibody against iNOS, the immunochemial staining was determined. Luteal cell DNA fragmentation was determined by flow cytometry. The results showed that no positive staining for iNOS was in CL1 and that iNOS was produced but limited to the periphery of CL2, while in the CL3, the spreading immunochemical staining was found inside the CL. No iNOS positive staining was detected in CL4. Meanwhile, DNA fragmentation increased dramatically when CL developed from CL2 to CL3 (p<0.05). In CL4, higher proportion of luteal cells still had fragmented DNA than that of luteal cells from CL1 or CL2 (p<0.05). These results indicate that iNOS expression is closely related to luteal cell apoptosis and then to luteal regression.