• Biomolecules & Therapeutics
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• v.12 no.4
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• pp.209-214
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• 2004

Lead has long been considered as a toxic environmental pollutant that severely damages the central nervous system. In various neurogenerative diseases, actrocytes become activated by proinflammatory cytokines. In the present study, we investigated whether lead (Pb$^{2+}$) affects inducible nitric oxide synthase (iNOS) expression in activated glial cells. Rat primary glial cells were stimulated with lipopolysaccharide (LPS, 1 ${\mu}$g/ml) plus IFN$_{\gamma}$(100 U/ml). Pre-treatment of Pb$^{2+}$ increased nitric oxide (NO) production in LPS/IFN$_{\gamma}$-stimulated glial cells. Lead itself, however, suppressed the basal production of NO in control glial cells. Addition of the iNOS inhibitors L-NAME (1 mM) and L-NNA (800 ${\mu}$M) prevented the Pb$^{2+}$-induced increase in NO production. Western blot analysis showed that pre-treatment of Pb$^{2+}$ augmented LPS/IFN$_{\gamma}$-induced increase in iNOS immunoreactivity, which was well correlated with the increased NO production. In addition, pre-treatment of Pb$^{2+}$ synergistically increased the iNOS mRNA expression induced by LPS and IFN${\gamma}$. The present results indicate that lead intoxication adversely affect brain function by potentiating iNOS expression and NO production in activated glial cells observed in various neurodegenerative diseases.

• Korean Journal of Pharmacognosy
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• v.42 no.4
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• pp.348-353
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• 2011

The aim of the present study is to investigate the cytokine production inhibitory effect of a Dictamni Radicis Cortex (DRC). DRC has been commonly used as important medicinal herb in China and it used to control eczema, atopic dermatitis, fever and inflammatory diseases. Inflammation, such as a bacterial infection in vivo metabolites, such as external stimuli or internal stimuli to the defense mechanisms of the biological tissue a variety of intracellular regulatory factors deulin inflammatory TNF-${\alpha}$, IL-$1{\beta}$, IL-6, IL-8, such as proinflammatory cytokines, prostagrandin, lysosomal enzyme, free radicals are involved in a variety of mediators. The present study was designed to determine the effect of the DRC on proinflammatory factors such as NO, iNOS expression and TNF-${\alpha}$, IL-$1{\beta}$, IL-6 in lipopolysaccharide (LPS) - stimulated RAW264.7 cells. The cell toxicity was determined by MTS assay. To evaluate of anti-inflammatory effect of DRC, amount of NO was measured using the NO detection kit and the iNOS expression was measured by reverse transcriptase polymerase chain reaction (RT-PCR). And proinflammatory cytokines were measured by ELISA kit. As a result, the DRC reduced NO, iNOS expression and TNF-${\alpha}$, IL-$1{\beta}$, IL-6 production without cytotoxicity. Our results suggest that the DRC may have an anti-inflammatory property through suppressing inflammatory mediator productions.

• Toxicological Research
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• v.27 no.2
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• pp.71-76
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• 2011

We demonstrate that baicalein, a bioactive flavonoid originally isolated from Scutellaria baicalensis, inhibits LPS-induced expression of iNOS gene in RAW 264.7 cells. Treatment of peritoneal macrophages and RAW 264.7 cells with baicalein inhibited LPS-stimulated nitric oxide production in a dose-related manner. Immunohistochemical staining of iNOS and RT-PCR analysis showed that the decrease of NO was due to the inhibition of iNOS gene expression in RAW 264.7 cells. Immunostaining of p65, EMSA, and reporter gene assay showed that baicalein inhibited NF-${\kappa}$B nuclear translocation, DNA binding, and transcriptional activation, respectively. Collectively, these series of experiments indicate that baicalein inhibits iNOS gene expression by blocking NF-${\kappa}$B nuclear translocation. Due to the critical role that NO release plays in mediating inflammatory responses, the inhibitory effects of baicalein on iNOS suggest that baicalein may represent a useful anti-inflammatory agent.

• Korean Journal of Acupuncture
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• v.34 no.1
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• pp.37-46
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• 2017

Objectives : The acupuncture about acupoint affects the production of NO, NOS, and NE.Local action of acupuncture is important for acupuncture treatment. To prove this, the revelation degree of NO, NOS, and NE was observed by stimulating the acupuncture at the connecting point of SP4, KI4, and LR5 in the depths of Superficial layer, Middle layer and Deep layer. Methods : Needles were inserted into rats, on each right and left sides of the connecting point, SP4, KI4 and LR5 acupoints which are the stream points of the foot meridian. After insertion, needles were retained for three minutes. After the retention, rat was sacrificed via cardiac puncture, and tissues of each SP4, KI4 and LR5 point near meridian vessel was extracted to examine the changes in the expression of NO, NOS and NE. Results : In terms of the effect in NO production, there was significant increase in the Superficial layer, Middle layer and Deep layer at KI4. In terms of the effect in NE production, there was significant decrease in the Superficial layer at SP4 and increase in the Superficial layer, Middle layer and Deep layer at LR5. In terms of the effect in nNOS production, there was significant increase in the Superficial layer, Middle layer and Deep layer at SP4 also in the Superficial layer at KI4. In terms of the effect in eNOS production, there was a significant increase in the Superficial layer, Middle layer and Deep layer at SP4, KI4 and LR5. In terms of the effect in iNOS production, there was significant increase in the Superficial layer, Middle layer and Deep layer at SP4, KI4 and LR5. Conclusions : The effect of acupuncture applied at the connecting point of six meridians of the foot on the activities of NO, NOS and NE could be observed, and it can be induced from the effect of needle stimulation on disrupted local and systemic nervous responses.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.315-320
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• 2013

Here, we show that radicicol, a fungal antibiotic, resulted in marked inhibition of inducible nitric oxide synthase (iNOS) transcription by the pancreatic beta cell line MIN6N8a in response to cytokine mixture (CM: TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$). Treatment of MIN6N8a cells with radicicol inhibited CM-stimulated activation of NF-${\kappa}B$/Rel, which plays a critical role in iNOS transcription, in a dose-related manner. Nitrite production in the presence of PD98059, a specific inhibitor of the extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) pathway, was dramatically diminished, suggesting that the ERK1/2 pathway is involved in CM-induced iNOS expression. In contrast, SB203580, a specific inhibitor of p38, had no effect on nitrite generation. Collectively, this series of experiments indicates that radicicol inhibits iNOS gene expression by blocking ERK1/2 signaling. Due to the critical role that NO release plays in mediating destruction of pancreatic beta cells, the inhibitory effects of radicicol on iNOS expression suggest that radicicol may represent a useful anti-diabetic activity.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.101-101
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• 2003

Prostaglandins (PGs) and nitric oxide (NO) 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. In our continuing efforts of searching for novel cancer chemopreventive agents from natural products, we isolated natural sesquiterpenoids as potential COX-2 and iNOS inhibitors in cultured lipopolysaccharide (LPS)-activated mouse macrophage RAW 264.7 cells. Alantolactone, a natural eudesmane-type sesquiterpenoid, exhibited a potent inhibition of COX-2 (IC50 = 0.4 $\mu\textrm{g}$/$m\ell$) and iNOS activity (IC50 = 0.08 $\mu\textrm{g}$/$m\ell$) in the assay system determined by PGE2 and NO accumulation, respectively. The inhibitory potential of alantolactone on the PGE2 and NO production was well coincided with the suppression of COX-2 and iNOS protein and mRNA expression in LPS-induced macrophages. Furthermore, alantolactone inhibited NF-kB but not AP-l binding activity on nuclear extracts evoked by LPS-stimulated macrophage cells, suggesting the possible involvement of NF-kB in the regulation of COX-2 and iNOS expression. In further study with COX-2-expressing human colon HT-29 cells, alantolactone inhibited the cell proliferation, down-regulated COX-2, and inhibited the ERK phosphorylation in the early time. These results suggest that a natural sesquiterpenoid alantolactone might be a potential lead candidate for further developing COX-2 or iNOS inhibitor possessing cancer chemopreventive or anti-inflammatory activity

• Natural Product Sciences
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• v.20 no.4
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• pp.227-231
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• 2014

Cimicifuga heracleifolia extract (CHE) was investigated for its effects on the release of nitric oxide (NO) and at the level of inducible nitric oxide synthase (iNOS) gene expression in mouse macrophages. We found that C. heracleifolia elicited a dose-dependent increase in NO production and the level of iNOS mRNA. Since, iNOS transcription has been shown to be under the control of the transcription factor $NF-{\kappa}B$, the effects of CHE on $NF-{\kappa}B$ activation were examined. Transient expression assays with $NF-{\kappa}B$ binding sites linked to the luciferase gene revealed that the increased level of iNOS mRNA, induced by CHE, was mediated by the $NF-{\kappa}B$ transcription factor complex. By using DNA fragments containing the $NF-{\kappa}B$ binding sequence, CHE was shown to activate the protein/DNA binding of $NF-{\kappa}B$ to its cognate site, as measured by electrophoretic mobility shift assay. These results demonstrate that C. heracleifolia stimulates NO production and is able to up-regulate iNOS expression through $NF-{\kappa}B$ transactivation.

• Applied Microscopy
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• v.38 no.3
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• pp.221-233
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• 2008

Endogenous nitric oxide (NO) has been known to regulate many physiological and pathological processes, especially the glandular secretion and blood flow. However, nitric oxide synthase (NOS) responsible for NO synthesis has not been well studied ultrastructurally in rat salivary gland. The present study was performed to investigate the distribution of nitric Oxide synthase isoforms (endothelial. neuronal, and inducible NOS). Immunoelectron microscopic study, using monoclonal mouse anti-endothelial NOS, anti-neuronal NOS, and anti-inducible NOS, was performed in the salivary gland of rat. Endothelial NOS (eNOS)-positive immunoreactivities were most prominent in the secretory granules of serous cells of the salivary gland of the rat. Immunoreactivities were well concentrated on serous secretory granules in the serous cells. However, weak eNOS-positive immunoreactivity was observed in the mucous secretory granules of the mucous cells. Positive endothelial NOS (eNOS) immunoreactivities were most prominent in the secretory granules of intralobular ducts. Ductal secretory granules and acinar serous secretory granules have a similar pattern of labeling as eNOS suggestings. Neural NOS (nNOS)-positive immunoreactivity was not detected in duct systems or in acinar cells. Inducible NOS (iNOS)-positive immunoreactivity was not seen in acinar and ductal cells. These results reveal the presence of eNOS in the salivary gland of the rat, which may be related with regulation of the glandular secretion and blood flow through the gland.

• Biomedical Science Letters
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• v.25 no.2
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• pp.196-200
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• 2019

Effect of retinoids, i.e., all-trans retinoic acid and 13-cis retinoic acid, on the activity of nitric oxide synthase (NOS) was evaluated in human malignant keratinocytes to examine the possible correlation of retinoids with NOS activities. All-trans retinoic acid and 13-cis retinoic acid did not alter the nitric oxide (NO) production. However, in the presence of lipopolysaccharide (LPS, $1{\mu}g/mL$), they significantly increased NO release in a dose-dependent manner until 48 h at concentrations of $50{\sim}100{\mu}M$. The degree of upregulation of NO by all-trans retinoic acid and 13-cis retinoic acid increased up to 35% and 37%, respectively, compared to that by the control, which demonstrated the upregulation of LPS-inducible nitric oxide synthase (iNOS)-dependent generation of NO as well as showing a crucial link between retinoids-induced activity and NOS. Findings of this study now suggest that the upregulation of LPS-iNOS activity may be associated with modulation of retinoids-induced control of cellular developmental processes, which may produce new therapeutics of retinoids in the complexity of how NO affects human keratinocytes.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.1
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• pp.95-110
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• 2008

목 적 : 급성 및 만성 염증 질환은 iNOS에 의해서 생성된 과량의 NO와 관련이 있다. 따라서 이러한 질병 치료를 목적으로 NO 생성 억제물질 또는 iNOS 발현 차단물질을 개발할 가치가 있다. 본 연구는 대사 안정성을 개선시킨 dimethoxycurcumin (DiMC)이 활성화된 대식세포에서 NO 생성 및 iNOS 발현을 제어할 수 있는지 조사하였다. 방 법 : RAW264.7 세포를 DiMC (양쪽 방향성 고리에 각각 2개의 methoxy group을 가짐), curcumin (양쪽 방향성 고리에 각각 1개의 methoxy group을 가짐), bis-demethoxycurcumin (양쪽 방향성 고리에 methoxy group이 없음; BDMC) 및 tetrahydrocurcumin (양쪽 방향성 고리에 각각 1개의 methoxy group을 가지고 있지만 중앙 7개 탄소 사슬에 이중결합이 없음; THC)로 각각 전처리한 후에 LPS로 자극하였다. 이들 전처리 물질의 효과를 비교하기 위하여, NO 생성, iNOS 발현, NF-kB p65 인산화 및 p65 DNA-binding 활성을 조사하였다. 결 과 : DiMC, curcumin 및 BDMC는 NO 생성, iNOS 발현 및 NF-kB 활성을 억제하였으며, 그 세기에 있어서 DiMC가 가장 크게 관찰되었고 그 다음 curcumin 그리고 BDMC 순으로 관찰되었다. THC는 어떠한 활성도 보이지 못했다. 결 론 :DiMC는 NO 생성 억제, iNOS 발현 차단 및 NF-kB 비활성을 유도할 수 있음을 알 수 있었다. 이러한 효과는 연속된 이중결합 및 methoxy group의 증가와 관련이 있는 것으로 판단된다.