• Title/Summary/Keyword: inducible NO synthase (iNOS)

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The Inhibitory Effect of Lycii Fructus on LPS-stimulated NF-${\kappa}B$ Activation and iNOS Expression in RAW 264.7 Macrophages

  • Kim, Beum-Seuk;Song, Yun-Kyung;Lim, Hyung-Ho
    • The Journal of Korean Medicine
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    • v.29 no.1
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    • pp.47-59
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    • 2008
  • Objective : Anti-inflammatory effects of the extract of Lycii Fructus on lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells were investigated. Method : In order to assess the cytotoxic effect of Lycii Fructus on the raw 264.7 macrophages 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was performed. Reverse transcription-polymerase chain reaction(RT-PCR) analysis of the mRNA levels of tumor necrosis factor-$\alpha$(TNF-$\alpha$) and inducible nitric oxide synthase(iNOS) was performed in order to provide an estimate of the relative level of expression of these genes. The protein level of the inhibitor of nuclear factor-${\kappa}B(I{\kappa}B)$ and nuclear factor-${\kappa}B$(NF-${\kappa}B$) activity was investigated by Western blot assay. NO production was investigated by NO detection. Result : Lycii Fructus suppressed NO production by inhibiting the LPS-induced expressions of iNOS and TNF-$^-\alpha$ mRNA and iNOS protein in RAW 264.7 macrophage cells. Also, Lycii Fructus suppressed activation of NF-${\kappa}B$ in the nucleus. Conclusion : These results show that the extract of Lycii Fructus has anti-inflammatory effect probably by suppressing iNOS expressions through the down-regulation of NF-${\kappa}B$ binding activity.

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Role of $NF-_{{\kappa}B}$ Binding Sites in the Regulation of Inducible Nitric Oxide Synthase by Tyrosine Kinase

  • Ryu, Young-Sue;Hong, Jang-Hee;Lim, Jong-Ho;Bae, So-Hyun;Ahn, Ihn-Sub;Seok, Jeong-Ho;Lee, Jae-Heun;Hur, Gang-Min
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.1
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    • pp.55-63
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    • 2001
  • In macrophages, lipopolysaccharide (LPS) alone or in combination with $interferon-{\gamma}\;(IFN-{\gamma})$ has been shown to release a nitric oxide (NO) through the increase of the transcription of the inducible nitric oxide synthase (iNOS) gene. To investigate the exact intracellular signaling pathway of the regulation of iNOS gene transcription by LPS plus $IFN-{\gamma},$ the effects of protein tyrosine kinase (PTK) inhibitor and protein kinase C (PKC) inhibitors on NO production, iNOS mRNA expression, nuclear $factor-_{\kappa}B\;(NF-_{\kappa}B)$ binding activity and the promoter activity of iNOS gene containing two $NF-_{\kappa}B$ sites have been examined in a mouse macrophage RAW 264.7 cells. LPS or $IFN-{\gamma}$ stimulated NO production, and their effect was enhanced synergistically by mixture of LPS and $IFN-{\gamma}.$ The PTK inhibitor such as tyrphostin reduced LPS plus $IFN-{\gamma}-induced$ NO production, iNOS mRNA expression and $NF-_{\kappa}B$ binding activity. In contrast, PKC inhibitors such as H-7, Ro-318220 and staurosporine did not show any effect on them. In addition, transfection of RAW 264.7 cells with iNOS promoter linked to a CAT reporter gene revealed that tyrphostin inhibited the iNOS promoter activity through the $NF-_{\kappa}B$ binding site, whereas PKC inhibitors did not. Taken together, these suggest that PTK, but not PKC pathway, is involved in the regulation of the iNOS gene transcription through the $NF-_{\kappa}B$ sites of iNOS promoter in RAW 264.7 macrophages by LPS plus $IFN-{\gamma}$.

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Induction of Inos Gene Expression by Polysaccharide Isolated from Poria Cocos Sclerotium

  • Jeon, Young-Jin
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2003.10b
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    • pp.164-164
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    • 2003
  • We show that PCSC, a polysaccharide isolated from the sclerotium of Poria cocos with one percent sodium carbonate, significantly induces nitric oxide (NO) production and inducible NO synthase (iNOS) transcription through the activation of nuclear factor-$\kappa$B/Rel (NF-$\kappa$B/Rel).(omitted)

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Potentiation of Inducible Nitric Oxide Expression by Indomethacin in Carageenin-treated Rat Paw Inflammation (Carrageenin으로 흰쥐 발 염증으로 Indomethacin에 의한 유도성 nitric oxide synthase의 발현증가)

  • 원혜영;강건욱;김영미;김낙두
    • YAKHAK HOEJI
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    • v.43 no.2
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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.

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Inhibition of Inducible Nitric Oxide Synthase Expression by YS 49, a Synthetic Isoquinoline Alkaloid, in ROS 17/2.8 Cells Activated with $TNF-{\alpha},\;IFN-{\gamma}$ and LPS

  • Kang, Young-Jin;Kang, Sun-Young;Lee, Young-Soo;Park, Min-Kyu;Kim, Hye-Jung;Seo, Han-Geuk;Lee, Jae-Heun;YunChoi, Hye-Sook;Chang, Ki-Churl
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.5
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    • pp.273-280
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    • 2004
  • Nitric oxide (NO) has been suggested to act as a mediator of cytokine-induced effects of turn over of bone. Activation of the inducible nitric oxide synthase (iNOS) by inflammation has been related with apoptotic cell death in osteoblast. YS 49, a synthetic isoquinoline alkaloid, inhibits NO production in macrophages activated with cytokines. In the present study, we investigated the molecular mechanism of YS 49 to inhibit iNOS expression in ROS 17/2.8 cells, which were activated with combined treatment of inflammatory cytokines $(TNF-{\alpha},\;IFN-{\gamma})$ and lipopolysaccharide (LPS). Results indicated that YS 49 concentration-dependently reduced iNOS mRNA and protein expression, as evidenced by Northern and Western blot analysis, respectively. The underlying mechanism by which YS 49 suppressed iNOS expression was not to affect iNOS mRNA stability but to inhibit activation and translocation of $NF-_kB$ by preventing the degradation of its inhibitory protein $I_kB_{\alpha}$. As expected, YS 49 prevented NO-induced apoptotic cell death by sodium nitroprusside. Taken together, it is concluded that YS 49 inhibits iNOS expression by interfering with degradation of phosphorylated inhibitory $_kB_{\alpha}\;(p-I_kB_{\alpha})$. These actions may be beneficial for the treatment of inflammation of the joint, such as rheumatoid arthritis.

Cedrela sinensis Leaves Suppress Oxidative Stress and Expressions of iNOS and COX-2 via MAPK Signaling Pathways in RAW 264.7 Cells

  • Bak, Min-Ji;Jeong, Jae-Han;Kang, Hye-Sook;Jin, Kyong-Suk;Ok, Seon;Jeong, Woo-Sik
    • Preventive Nutrition and Food Science
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    • v.14 no.4
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    • pp.269-276
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    • 2009
  • Overproduction of reactive oxygen species (ROS), including nitric oxide (NO), could be associated with the pathogenesis of various diseases such as cancer and chronic inflammation. Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are known to play key roles in the development of these diseases. Cedrela sinensis leaves have been used in Asian countries as a traditional remedy for enteritis, dysentery and itching. In the present study, we investigated the anti-inflammatory effects of Cedrela sinensis leaves in lipopolysaccharide (LPS)- stimulated RAW 264.7 macrophages. Powder of C. sinensis leaves was extracted with 95% ethanol and fractionated with a series of organic solvents including n-hexane, dichloromethane, ethyl acetate, n-butanol, and water. The dichloromethane (DCM) fraction strongly inhibited NO production possibly by down-regulating iNOS and COX-2 expression, as determined by Western blotting. Hydrogen peroxide-induced generation of reactive oxygen species (ROS) was also effectively inhibited by the DCM fraction from C. sinensis leaves. In addition, C. sinensis inhibited LPS-mediated p65 activation via the prevention of IκB-$\alpha$ phosphorylation. Furthermore, mitogen-activated protein kinases (MAPKs) such as ERK 1/2 and p38 were found to affect the expression of iNOS and COX-2 in the cells. Taken together, our data suggest that leaves of C. sinensis could be used as a potential source for anti-inflammatory agents.

Inhibition of Inducible Nitric Oxide Synthase and Cyclooxygenase-2 by Gamijihwang-tang Via Suppression of Nuclear Factor-B Activation in RAW 264.7 cells

  • Jang Du-Hyun;Kim Ji-Young;Han Eun-Hee;Park Hee-Ok;Kim Dong-Hee;Jeong Hye-Gwang;Yoo Dong-Yeol
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.5
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    • pp.1405-1410
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    • 2005
  • Asthma is recognized today as an inflammatory disease of the lung characterized by acute non-specific airway hypersensitiveness in association with chronic pulmonary inflammation. Gamijihwang-tang(GJT), a fortified prescription of YMJHT, is applied for the treatments of chronic coughing and asthma, and post-delivery coughing and asthma in the gynecology. Also in the clinical practice, GJT is known to be very effective for controlling coughing and asthma as a cold sequoia. In this study, we investigated the effects of GJT on the lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production, and on the level of inducible nitric oxide synthase (iNOS) and Cyclooxygenase-2 expression in murine macrophage RAW 264.7 cells. We found that GJT inhibited LPS-induced NO and $PGE_2$ production in a dose dependent manner. Furthermore, GJT inhibited the expression of LPS-induced iNOS and COX-2 protein and mRNA expression in RAW 264.7 macrophages. Treatment with GJT of RAW 264.7 cells transfected with a reporter construct indicated a reduced level of LPS-induced nuclear factor-KB (NF-kB) activity and effectively lowered NF-kB binding as measured by transient transfection assay. These results suggest that the main inhibitory mechanism of the GJT may be the reduction of iNOS and COX-2 gene expression through blocking of NF-kB activation.

Sopungdojeok-San Inhibits Atopy-liked Dermal Inflammation through Regulation of iNOS mRNA Expresssion & NO production (소풍도적산의 iNOS 발현과 NO 생성 억제가 아토피 피부염에 미치는 영향)

  • Ahn, Sang-Hyun;Kim, Jin-Taek
    • Herbal Formula Science
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    • v.15 no.1
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    • pp.199-211
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    • 2007
  • Inducible nitric oxide synthase (iNOS) are important inflammation enzyme and severe up-nitric oxide (NO) production by this enzyme has been intricated with pathogenesis of inflammation diseases as atopy dermatitis. The present study was designed in order to determine whether Sopungdojeok-san could inhibit atopy dermatitis through modulation of iNOS mRNA expression and NO production, We found that iNOS mRNA expression and NO production in RAW 264.7 macrophages stimulated with lipopolysaccharide dose-dependantly decreased by Sopungdojeok-san extract treatment (0.4 - 1.0 mg/ml). The distribution of iNOS positive reacted cell in atopy dermatitis elicited skin of mice were remarkably decreased by Sopungdojeok-san administration (2.5 ml/kg/day). The SOD ability of Sopungdojeok-san were dose-dependantly increased from 0.6 mg/ ml than butylated hydroxyanisole. These data likely indicate that Sopungdojeok-san may act as inflammatory regulator for atopy dermatitis may be possible to develop useful agent for chemopreventation of NO-intricate inflammatory diseases.

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Cheonggi-san Inhibits Atopy Dermatitis in NC/Nga Mouse through Regulation of iNOS mRNA Expresssion & NO production (청기산(淸肌散)의 iNOS 발현과 NO 생성 억제가 NC/Nga 생쥐의 아토피 피부염에 미치는 영향)

  • Ahn, Sang-Hyun;Kim, Ho-Hyun;Kim, Jin-Taek
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.5
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    • pp.1092-1098
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    • 2007
  • Inducible nitric oxide synthase (iNOS) are important inflammation enzyme and severe up-nitric oxide (NO) production by this enzyme has been intricate with pathogenesis of atopy dermatitis. The present study was designed in order to determine whether Cheonggi-san could inhibit atopy dermatitis through modulation of iNOS mRNA expression and NO production. We found that iNOS mRNA expression and NO production in RAW 264.7 macrophages stimulated with lipopolysaccharide dose-dependantly decreased by Cheonggi-san extract treatment (0.5 - 2.0 mg/ml). The distribution of iNOS positive reacted cell in NC/Nga mice with atopy dermatitis were decreased by Cheonggi-san extract treatment (2.5 ml/kg/day) and apoptosis were increased. These data likely indicate that Cheonggi-san may act as inflammatory regulator for atopy dermatitis and may be possible to develop useful agent for chemoprevention of NO intricate inflammatory diseases.

Effect of Various Herbal Extracts on Nitric Oxide Production in Lipopolysaccharide-induced Murine Peritoneal Macrophages

  • Ko, Young-Kwon;Seo, Dong-Wan;Ahn, Seong-Hoon;Bae, Gyu-Un;Yoon, Jong-Woo;Hong, Sung-Youl;Lee, Hoi-Young;Han, Jeung-Whan;Lee, Hyang-Woo
    • Biomolecules & Therapeutics
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    • v.7 no.3
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    • pp.210-215
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    • 1999
  • Nitric oxide (NO) can mediate numerous physiological processes, including vasodilation, neurotransmission, cytotoxicity, secretion and inflammatory response. The regulation of NO production by inducible NO synthase (iNOS) is considered to be the possible target of the development of anti-inflammatory agent, based on the observation that NO can activate cyclooxygenase, which results in the synthesis of prostaglandins. In an effort to screen new inhibitor of NO production from about 352 species of herbal extracts, we found 9 species with 50% or more inhibitory effect on NO production. Especially, the dose-dependent inhibition of NO production in lipopolysaccharide-treated macrophages by two of the herbal extracts (Artemisiae asiaticae Herba and Saussureae Radix) was due to the decrease in the expression of iNOS.

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