• 제목/요약/키워드: NO production inhibitors

검색결과 125건 처리시간 0.029초

고량강으로부터 분리된 galangin의 RAW 264.7 세포주에서 LPS로 유도된 nitric oxide 생성 저해활성 (Inhibitory Effect of Galangin from Alpinia officinarum on Lipopolysaccharide-induced Nitric Oxide Synthesis in RAW 264.7 macrophages)

  • 이화진
    • 한국식품과학회지
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    • 제46권4호
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    • pp.511-515
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    • 2014
  • 각종 염증성 질환 및 패혈증으로 인한 치명적인 저혈압을 예방치료하는 약물 개발을 위한 기초 연구로서 유도성 NOS (inducible nitric oxide synthase, iNOS) 에 의한 NO의 과다 생성을 저해하는 성분을 천연물로부터 찾아내고자 본 연구를 수행하였다. NO 생성 저해활성의 검정은 대식세포주인 RAW 264.7 세포를 LPS로 활성화한 후, 유도되는 iNOS에 의해 생성되는 NO를 Griess 시약을 이용해 $NO_2{^-}$의 형태로 정량하였다. 또한 Western blot 실험 및 RT-PCR 실험을 시행하여 iNOS의 mRNA의 발현 및 단백 합성에 대한 영향을 조사하였다. 고량강(Alpinia officinarum Hance, Zingiberaceae)의 메탄올 추출물로부터 극성에 따른 용매 분획을 시행하여 활성성분을 분리하고 분광학적 분석법을 이용하여 분리한 단일성분이 flavonol 구조인 3,5,7-trihydroxy-2-phenylchromen-4-one (galangin, GLG)임을 확인하였다. 작용기전을 알아보기 위해, Western blot 및 RT-PCR 실험결과, 분리한 flavonol 성분(GLG)의 NO 생성저해 활성은 iNOS mRNA발현을 저해하여 iNOS 효소 단백질의 생성이 억제됨에 기인하는 것으로 확인하였다. 따라서, 고량강 추출물로부터 분리한 flavonol 화합물(GLG)이 iNOS 발현의 억제를 통해 다량의 NO 생산을 저해함으로써, 고량강(Alpinia officinarum)의 NO 과량생성과 관련된 염증성 질환에 대한 응용 가능성이 클 것으로 기대된다.

Effects of Fucoidan on Neuronal Cell Proliferation: Association with NO Production through the iNOS Pathway

  • Lee, Hye-Rim;Do, Hang;Lee, Sung-Ryul;Sohn, Eun-Soo;Pyo, Suhk-Neung;Son, Eun-Wha
    • Preventive Nutrition and Food Science
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    • 제12권2호
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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.

보물 제1141호 한천사 출토 금동자물쇠 보존처리 (Conservation of gilt bronze locks (Treasure No. 1141) excavated from Hancheonsa temple)

  • 고형순;유재은;이재성
    • 보존과학연구
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    • 통권23호
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    • pp.149-162
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    • 2002
  • Gilt bronze locks(Treasure No. 1141) excavated from Hancheonsa temple are artifacts of Goryeo Dynasty. The locks underwent a conservation process from October 2001 to July 2002. The process included cleaning and the application of corrosion inhibitors, Benzotriazolesolution, as well as reinforcement treatment with Paraloid NAD-10 solution,an acrylic resin. Non-destructive XRF analysis unveil that the artifacts are made of an alloy of copper(Cu), tin(Sn) and lead(Pb), but the gilt layer is too thin to analyze the purity of the gold or the exact production method. Gilt bronze locks are important materials because they preserve all the structures of locks in Goryeo Dynasty to the smallest detail. The surface pattern is revealed through the conservation process and components of the alloy through material analysis.

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Suppressive effects on the expression of cyclooxygenase-2 and inducible nitric oxide synthase by a natural sesquiterpenoid in lipopolysaccharide-stimulated mouse macrophage cells

  • Min, Hye-Young;Park, Hyen-Joo;Park, Eun-Jung;Lee, Sang-Kook
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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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

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Depression of $Ca^{2+}$ Influx in Complement C5a-stimulated Neutrophils by Calmodulin Inhibitors

  • Ham, Dong-Suk;Kim, Hyun-Ho;Han, Eun-Sook;Lee, Chung-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권1호
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    • pp.109-117
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    • 1998
  • Role of $Ca^{2+}$/calmodulin complex in intracellular $Ca^{2+}$ mobilization in neutrophils has not been clearly elucidated. In this study, effects of chlorpromazine, trifluoperazine and imipramine on the intracellular $Ca^{2+}$ mobilization, including $Ca^{2+}$ influx, in C5a-activated neutrophils were investigated. Complement C5a- stimulated superoxide production and myeloperoxidase release in neutrophils were inhibited by chlorpromazine, trifluoperazine and imipramine, except no effect of imipramine on myeloperoxidase release. A C5a-elicited elevation of [$Ca^{2+}$]i in neutrophils was inhibited by chlopromazine, trifluoperazine, imipramine, staurosporine, genistein, EGTA, and verapamil but not affected by pertussis toxin. The intracellular $Ca^{2+}$ release in C5a-activated neutrophils was not affected by chlorpromazine and imipramine. Chlorpromazine and imipramine inhibited $Mn^{2+}$ influx by C5a-activated neutrophils. Thapsigargin-evoked $Ca^{2+}$ entry was inhibited by chlorpromazine, trifluoperazine, imipramine, genistein, EGTA and verapamil, while the effect of staurosporine was not detected. The results suggest that $Ca^{2+}$/calmodulin complex is involved in the activation process of neutrophils. The depressive action of calmodulin inhibitors on the elevation of cytosolic $Ca^{2+}$ level in C5a-activated neutrophils appears to be accomplished by inhibition of $Ca^{2+}$ influx from the extracellular medium.

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Characterization of $ET_B$ Receptor-mediated Relaxation in Precontracted Mesenteric Artery from Streptozotocin-induced Diabetic Rats

  • Eom, Yang-Ki;Kim, Koan-Hoi;Rhim, Byung-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제9권5호
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    • pp.305-314
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    • 2005
  • Diabetes mellitus is associated with vascular complications, including an impairment of vascular function and alterations in the reactivity of blood vessels to vasoactive substances in various vasculature. In the present study, the authors have observed endothelin-B ($ET_B$) receptor agonist-induced relaxation in precontracted mesenteric arterial segments from streptozotocin (STZ)-induced diabetic rats, which was not shown from control rats or in other arterial segments from diabetic rats. Accordingly, the goal of this study was to investigate in what way STZ-induced diabetes altered reactivity of the mesenteric arterial bed and to examine the causal relaxation, if any, between this $ET_B$ receptor-mediated relaxation and endothelial paracrine function, especially nitric oxide (NO) production. The relaxation induced by $ET_B$ agonists was not observed in mesenteric arteries without endothelium. The relaxation to $ET_B$ agonists was completely abolished by pretreatment with BQ788, but not by BQ610. $N_{\omega}-nitro-L-arginine$ methyl ester and soluble guanylate cyclase inhibitors, methylene blue or LY83583 significantly attenuated the relaxant responses to $ET_B$ agonists, respectively. When the expression of eNOS and iNOS was evaluated on agarose gel stained with ethidium bromide, the expression of eNOS mRNA in diabetic rats was significantly decreased, but the expression of iNOS was increased compared with control rats. Furthermore, the iNOS-like immunostaining was densely detected in the endothelium and slightly in the arterial smooth muscle of diabetic rats, but not in control rats. These observations suggest that $ET_B$ receptor may not play a role in maintaining mesenteric vascular tone in normal situation. However, the alterations in $ET_B$ receptor sensitivity were found in diabetic rats and lead to the $ET_B$ agonist-induced vasorelaxation, which is closely related to NO production. In the state of increased vascular resistance of diabetic mesenteric vascular bed, enhanced NO production by activation of iNOS could lead to compensatory vasorelaxation to modulate adequate perfusion pressure to splanchnic area.

Molecular Mechanism of NO-induced Cell Death of PC12 Cells by $IFN{\gamma}\;and\;TNF{\alpha}$

  • Yi, Seh-Yoon;Han, Seon-Kyu;Lee, Jee-Yeon;Yoo, Young-Sook
    • Molecular & Cellular Toxicology
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    • 제1권3호
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    • pp.196-202
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    • 2005
  • Nitric oxide (NO) is a small, diffusible, and highly reactive molecule, which plays dichotomous regulatory roles under physiological and pathological conditions. NO promotes apoptosis in some cells, and inhibits apoptosis in other cells. In the present study, we attempted to characterize the NO signaling pathway and cellular response in PC12 cells treated with cytokines. $IFN{\gamma}\;and\;TNF{\alpha}$ treatment resulted in a synergistic increase of nitrite accumulation, with the induction of inducible nitric oxide synthase (iNOS) in the PC12 cells. Moreover, as nitrite concentration increased, cell viability decreased. In order to explore MAP kinase involvement in nitric oxide production resultant from $IFN{\gamma}\;and\;TNF{\alpha}$ stimulation, we measured the activation of MAP kinase using specific MAP kinase inhibitors. PC12 cells pretreated with SB203580, a p38 MAP kinase-specific inhibitor, resulted in the inhibition of iNOS expression and NO production. However, PD98059, an ERK/MAP kinase-specific inhibitor, was not observed to exert such an effect. In addition, Stat1 activated by $IFN{\gamma}\;and\;TNF{\alpha}$ was interacted with p38 MAPK. These data suggest that p38 MAP kinase mediates cytokine-mediated iNOS expression in the PC12 cells, and Jak/Stat pathway interferes with p38 MAPK signaling pathway.

혈청이 마우스 간 세포주 BNL CL.2의 Nitric Oxide 생성에 미치는 영향 (Effects of Serum on Nitric Oxide Production in Embryonic Mouse Liver Cell Line BNL CL.2)

  • 김유현;김신무;배현옥;유지창;정헌택;진효상
    • 대한의생명과학회지
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    • 제5권1호
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    • pp.85-93
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    • 1999
  • 마우스 간 세포주인 BNL CL.2의 시험관내 배양에서 혈청과 IFN-$\gamma$가 세포주의 nitric oxide (NO)생성과 세포 손상에 미치는 영향을 알아보기 위한 실험을 하였다. 혈청이 공급된 배양에서 IFN-$\gamma$에 의한 세포 생존율은 거의 변동이 없었으나, 혈청을 제거한 배양에서는 약 65%의 생존율이 유지되었으며, NO생성 억제제인 N$^{G}$-monomethy-L-arginine (NMA)의 첨가는 농도 의존적으로 세포의 생존율을 감소시켰다. 혈청이 제거된 BNL CL.2 세포주는 IFN-$\gamma$ 단독 처리에서도 NO를 생성할수 있었으며, IFN-$\gamma$와 lipopolysaccharide (LPS)의 복합 처리는 세포주의 NO 생성을 상승적으로 증가시 켰다. 또한 protein tyrosine kinase (PTK) inhibitor인 herbimycin A와 genistein에 의해서 NO 생성이 억제되어 PTK의 활성이 혈청이 고갈된 BNL CL.2세포에서 NO의 생성에 중요한 역할을 담당하고 있기 때문으로 판단된다. IFN-$\gamma$의 독성은 혈청을 제거시킬 때 NO 생성 억제제에 상승적으로 간세포를 손상시키며, 이때 NO가 IFN-$\gamma$에 의해 유도된 손상을 어느 정도 억제시키는 것을 알 수 있었다.

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Proinflammatory Cytokine and Nitric Oxide Production by Human Macrophages Stimulated with Trichomonas vaginalis

  • Han, Ik-Hwan;Goo, Sung-Young;Park, Soon-Jung;Hwang, Se-Jin;Kim, Yong-Seok;Yang, Michael Sungwoo;Ahn, Myoung-Hee;Ryu, Jae-Sook
    • Parasites, Hosts and Diseases
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    • 제47권3호
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    • pp.205-212
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    • 2009
  • Trichomonas vaginalis commonly causes vaginitis and perhaps cervicitis in women and urethritis in men and women. Macrophages are important immune cells in response to T. vaginalis infection. In this study, we investigated whether human macrophages could be involved in inflammation induced by T. vaginalis. Human monocyte-derived macrophages (HMDM) were co-cultured with T. vaginalis. Live, opsonized-live trichomonads, and T. vaginalis Iysates increased proinflammatory cytokines, such as TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 by HMDM. The involvement of nuclear factor (NF)-${\kappa}B$ signaling pathway in cytokine production induced by T. vaginalis was confirmed by phosphorylation and nuclear translocation of p65 NF-${\kappa}B$. In addition, stimulation with live T. vaginalis induced marked augmentation of nitric oxide (NO) production and expression of inducible NO synthase (iNOS) levels in HMDM. However, trichomonad-induced NF-${\kappa}B$ activation and TNF-${\alpha}$ production in macrophages were significantly inhibited by inhibition of iNOS levels with L-NMMA (NO synthase inhibitor). Moreover, pretreatment with NF-${\kappa}B$ inhibitors (PDTC or Bay11-7082) caused human macrophages to produce less TNF-${\alpha}$. These results suggest that T. vaginalis stimulates human macrophages to produce proinflammatory cytokines, such as IL-1, IL-6, and TNF-${\alpha}$, and NO. In particular, we showed that T. vaginalis induced TNF-${\alpha}$ production in macrophages through NO-dependent activation of NF-${\kappa}B$, which might be closely involved in inflammation caused by T. vaginalis.

길경 사포닌 분획의 NO생성과 관련된 면역조절작용을 통한 대식세포의 항암활성에 미치는 효과 (Anti-tumor Activity of Saponin Fraction of Platycodon gradiflourm through Immunomodulatory Effects associated with NO production in RAW264.7 cells)

  • 정명근;손은화
    • 한국자원식물학회지
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    • 제24권5호
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    • pp.557-563
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    • 2011
  • 본 연구는 길경 사포닌 추출물(PGS)를 이용하여 대식세포의 면역조절능력을 평가하였으며, 탐식작용, 항암작용, 항염증 작용에 모두 유의적인 효과를 나타내었다. 특히, 본 연구에서는 농도의존적으로 매우 유의적이게 나타난 PGS의 항암작용 기전을 측정하기 위하여 암세포 독성 물질로 알려진 NO 분비량을 측정하였으며, PGS에 의해 NO의 생성을 증가함을 확인하였다. 또한, PGS가 NO 생성 억제제 NIL을 함께 처리하였을 때 항암효과가 나타나지 않게 됨을 재확인함으로써, PGS 10 ${\mu}g/mL$에서 나타낸 대식세포의 항암효과는 일부 NO 생성 및 분비에 의한 작용 기전임을 보여주었다. PGS의 면역조절작용 중 항염증효과 실험에서는 PGS가 염증환경에서 과도하게 분비된 NO를 다소 억제하는 경향을 보였으나, 항염증조절에서 대표적인 물질로 알려진 TNF-${\alpha}$ 조절에는 효과를 나타내지 않았다. PGS가 염증환경에서의 TNF-${\alpha}$억제조절에는 영향을 미치지 않았으나 TNF-${\alpha}$는 항암물질로도 알려져 있으므로 향후 PGS의 항암효과에 대한 연구에서 TNF-${\alpha}$의 생성에 관한 연구는 NO를 매개하는 항암 효과 외에 다른 기전을 설명해줄 수 있을 것으로 보인다. 이러한 결과들은 PGS가 항암요법의 보조제 및 면역보조제로써의 활용에 개발 가능성이 있다는 것을 보여준다.