• Biomedical Science Letters
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• v.19 no.2
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• pp.168-172
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• 2013

Toll-like receptors (TLRs) play an important role for host defense against invading pathogens. TLR4 has been identified as the receptor for lipopolysaccharide (LPS), which is a cell wall component of gram-negative bacteria. The activation of TLR4 signaling by LPS leads to the activation of NF-${\kappa}B$ and the expression of pro-inflammatory gene products such as cytokines, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). To evaluate the therapeutic potential of (E)-1-(2-(2-nitrovinyl)phenyl)pyrrolidine (NVPP), previously synthesized in our laboratory, NF-${\kappa}B$ activation and iNOS and COX-2 expression induced by LPS were examined. NVPP inhibited the activation of NF-${\kappa}B$ induced by LPS. NVPP also suppressed the iNOS expression induced by LPS but it did not suppress COX-2 expression induced by LPS. These results suggest that NVPP has the specific mechanism for anti-inflammatory responses.

• Biomedical Science Letters
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• v.24 no.2
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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.

• Biomedical Science Letters
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• v.23 no.2
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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.

• 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.

• 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.

• Biomedical Science Letters
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• v.25 no.1
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• pp.60-65
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• 2019

Toll-like receptors (TLRs) are one of the families of pattern recognition receptors (PRR) operating in the innate immunity. TLRs have the ability to recognize relatively conserved microbial components, which are generally referred to as pathogen-associated molecular patterns (PAMPs). 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 pristimerin, which is a naturally occurring triterpenoid compound from Celastraceae plants, iNOS expression induced by MALP-2 (TLR2 and TLR6 agonist), Poly[I:C] (TLR3 agonist), or LPS (TLR4 agonist) were examined. Pristimerin suppressed the iNOS expression induced by MALP-2, Poly[I:C], or LPS. These results suggest that pristimerin can modulate TLRs signaling pathways leading to decreased inflammatory gene expression.

• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.777-783
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• 2015

The nitric oxide (NO) formation and intrinsic nitrosation may be involved in the possible mechanisms of liver fluke-associated carcinogenesis. We still do not know much about the responses of inducible NO synthase (iNOS) induced by Clonorchis sinensis infection. This study was conducted to explore the pathological lesions and iNOS expressions in the liver of mice with different infection intensity levels of C. sinensis. Extensive periductal inflammatory cell infiltration, bile duct hyperplasia, and fibrosis were commonly observed during the infection. The different pathological responses in liver tissues strongly correlated with the infection intensity of C. sinensis. Massive acute spotty necrosis occurred in the liver parenchyma after a severe infection. The iNOS activity in liver tissues increased, and iNOS-expressing cells with morphological differences were observed after a moderate or severe infection. The iNOS-expressing cells in liver tissues had multiple origins.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.410-413
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• 1999

In bioassay-guided search for inducible nitric oxide synthase (iNOS) inhibitory compounds from higher plants of South Korea, two $\beta$-carboline (2) have been isolated form the cortex of Melia azedarach var. japonica. The structures of these compounds were elucidated on the basis of spectroscopic data. Compounds 1 to 2 showed marked inhibitory activity of iNOS on LPS-and interferon-${\gamma}$-stimulated RAW 264.7 cells.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.131-131
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• 2001

Prostaglandins and nitric oxide produced by inducible cyclooygenase (COX-2) and nitric oxide synthase (iNOS), respectively, have been implicated as important mediators in the process of inflammation and carcinogenesis. On this line, the potential COX-2 or iNOS inhibitors have been considered as anti-inflammatory and cancer chemopreventive agents.(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)