• 제목/요약/키워드: Cyclooxygenase I

검색결과 673건 처리시간 0.02초

청훈화담탕가미방이 국소뇌혈유량 및 평균혈압에 미치는 작용기전 연구(IV) (The Mechanism Study of Cheonghunhwadam-tang Gamypang on the Regional Cerebral Blood Flow and Mean Arterial Blood Pressure in Rats(IV))

  • 정현우;김천중
    • 동의생리병리학회지
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    • 제17권4호
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    • pp.1013-1018
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    • 2003
  • Cheonghunhwadam-tang(CHT) have been used in oriental medicine for many centuries as a therapeutic agent of vertigo by wind, fire and phlegm. CTG was CHT adding Aurantii FructusㆍGastrodae Rhizoma. CTG was significantly increased regional cerebral blood f1ow(rCBF) in a dose-dependent, and CTG was decreased mean arterial blood pressure(MABP) compared with normal MABP(100%) in a low dosage, but was increased MABP in a dose-dependent, was aliked with normal MABP in a high-dosage. Therefore, purpose of this Study was to investigate experimental mechanism of CHTAG on the cerebral hemodynamics(rCBF, MABP) in rats. The changes of rCBF and MABP were determinated by Laser-Doppler Flowmetry(LDF). The results were as follows ; Pretreatment with indomethacin(3㎎/㎏, i.v.) was significantly inhibited CTG induced increase of rCBF and pretreated with propranolol(3㎎/㎏, i.v.) was inhibited CTG induced increase of rCBF, but pretreatment with methylene blue(10㎍/㎏, i.v) was increased CTG induced increase of rCBF. Pretreatment with indomethacin was decreased CTG induced increase of MABP, but pretreatment with propranolol and methylene blue were increased CTG induced increase of MABP. This results suggest that the mechanism of CTG is mediated by cyclooxygenase.

Inhibitory Action of Tsunokaori Tangor Peel on the Lipopolysaccharide-Induced Inflammatory Response in RAW 264.7 Macrophage Cells

  • Choi, Soo-Youn;Hwang, Joon-Ho;Ko, Hee-Chul;Park, Soo-Young;Kim, Gi-Ok;Kim, Duck-Hee;Chang, Ih-Seop;Kwon, H.-Moo;Kim, Se-Jae
    • Food Science and Biotechnology
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    • 제15권2호
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    • pp.270-276
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    • 2006
  • We evaluated the effects of extracts of Tsunokaori tangor peel on lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin $E_2\;(PGE_2)$ in RAW 264.7 cells. The ethyl acetate fraction of Tsunokaori tangor peel (EA-TTP) markedly inhibited the production of NO and $PGE_2$ in LPS-stimulated RAW 264.7 cells. Consistent with these findings, the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins were down-regulated in a dose-dependent manner. Additionally, EA-TTP decreased the expression iNOS mRNA but not COX-2 mRNA. To determine the upstream signaling mechanism for the down-regulation of LPS-induced iNOS expression, we investigated the effect of EA-TTP on the degradation and re-synthesis of $I{\kappa}B{\alpha}$. EA-TTP dose-dependently delayed $I{\kappa}B{\alpha}$ degradation and increased $I{\kappa}B{\alpha}$ re-appearance following degradation, suggesting this as the mechanism by which EA-TTP suppressed iNOS gene expression. The EA-TTP also dose-dependently reduced the expression of the cellular stress-response protein heme oxygenase-1, and inhibited the LPS-induced sustained activation of extracellar signal-regulated kinase (ERK).

Lipopolysaccharide로 처리 된 RAW264.7 세포에서 고마리 추출물의 항염증 효과 (The Anti-Inflammatory Effects of Persicaria thunbergii Extracts on Lipopolysaccharide-Stimulated RAW264.7 Cells)

  • 김상보;성영애;장희재;김군도
    • 생명과학회지
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    • 제21권12호
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    • pp.1689-1697
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    • 2011
  • 본 연구는 고마리 추출물이 가지는 항염증 활성을 알아보기 위하여 쥐의 대식세포(RAW264.7 cell)에 Lipopolysaccharide (LPS)를 처리하여 염증반응을 유도하고 이때 발생되는 Nitric oxide (NO)의 생성 억제를 확인하였다. 또한 염증에서 중요하게 알려져 있는 Inducible nitric oxide synthase (iNOS), Cyclooxygenase-2 (COX-2), Nuclear factor-kappa B (NF-${\kappa}B$) 단백질들의 발현을 비교하였고, 추가적으로 NF-${\kappa}B$ 단백질의 핵 내부로의 이전 및 활성을 확인하였다. 메탄올 추출물은 NO 생성 및 iNOS, COX-2, NF-${\kappa}B$ 단백질의 발현을 억제하고, 세포를 보호하는 효과를 가지는 Heme oxygenase-1 (HO-1) 단백질의 발현을 증가시켰다. 위 결과를 바탕으로 하여 n-butanol, hexane, ethyl acetate 용매를 이용한 추가적인 분획을 실시하였다. 이들 분획 중 고마리의 ethyl acetate 추출물은 Prostaglandin $E_2$ ($PGE_2$), NO 생성을 억제 하였으며, iNOS, COX-2 단백질들의 발현을 감소, NF-${\kappa}B$의 핵 내부로의 이동을 억제하는 효과가 높다는 것을 확인하였다. 이러한 연구결과는 고마리 식물이 좋은 항염증 활성을 가지고 있음을 나타내며, 지속적인 분획으로 고마리 식물이 가지는 항염증 활성 물질을 선별하여 그 작용기작을 규명하는 연구가 필요하다.

Ginsenoside Rp1, a Ginsenoside Derivative, Blocks Promoter Activation of iNOS and COX-2 Genes by Suppression of an IKKβ-mediated NF-κB Pathway in HEK293 Cells

  • Shen, Ting;Lee, Jae-Hwi;Park, Myung-Hwan;Lee, Yong-Gyu;Rho, Ho-Sik;Kwak, Yi-Seong;Rhee, Man-Hee;Park, Yung-Chul;Cho, Jae-Youl
    • Journal of Ginseng Research
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    • 제35권2호
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    • pp.200-208
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    • 2011
  • Ginsenoside (G) $Rp_1$ is a ginseng saponin derivative with anti-cancer and anti-inflammatory activities. In this study, we examined the mechanism by which G-$Rp_1$ inhibits inflammatory responses of cells. We did this using a strategy in which DNA constructs containing cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) promoters were transfected into HEK293 cells. G-$Rp_1$ strongly inhibited the promoter activities of COX-2 and iNOS; it also inhibited lipopolysaccharide induced upregulation of COX-2 and iNOS mRNA levels in RAW264.7 cells. In HEK293 cells G-$Rp_1$ did not suppress TANK binding kinase 1-, Toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-${\beta}$ (TRIF)-, TRIF-related adaptor molecule (TRAM)-, or activation of interferon regulatory factor (IRF)-3 and nuclear factor (NF)-${\kappa}$B by the myeloid differentiation primary response gene (MyD88)-induced. However, G-$Rp_1$ strongly suppressed NF-${\kappa}$B activation induced by I${\kappa}$B kinase (IKK)${\beta}$ in HEK293 cells. Consistent with these results, G-$Rp_1$ substantially inhibited IKK${\beta}$-induced phosphorylation of $I{\kappa}B{\alpha}$ and p65. These results suggest that G-$Rp_1$ is a novel anti-inflammatory ginsenoside analog that can be used to treat IKK${\beta}$/NF-${\kappa}$B-mediated inflammatory diseases.

강화사자발쑥의 마크로파지 RAW 264.7세포에 대한 Tumor Necrosis Factor-$\alpha$, Prostaglandin $E_2$, Cyclooxygenase-2 및 LPS 유도 Nitric Oxide 생성 저해 (Extracts of Artemisia princeps Pampanini Inhibit Lipopolysaccharide-induced Nitric Oxide, Cyclooxygenase-2, Prostaglandin $E_2$, and Tumor Necrosis Factor-$\alpha$ Production from Murine Macrophage RAW 264.7 Cells)

  • 윤준용;최세영;박표잠;정해곤;신흥묵;석경호;임병우
    • 한국약용작물학회지
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    • 제16권5호
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    • pp.326-331
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    • 2008
  • To search for immunoactive natural products exerting anti-inflammatory activity, we have evaluated the effects on the water extracts of Artemisia princeps Pampanini (APP) on lipopolysaccharide-induced nitric oxide (NO), tumor necrosis factor-$\alpha$ (TNF-$\alpha$), and prostaglandin $E_2$ ($PGE_2$) production by RAW 264.7 macrophage cell line. Our data indicate that this extract is a potent inhibitor of NO production and it also significantly decreased PGE2 and TNF-$\alpha$ production. Consistent with these results, the protein and mRNA expression level of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was inhibited by water extracts of APP in a dose-dependent manner. These results suggest that APP may exert anti-inflammatory and analgesic effects possibly by suppressing the inducible NO synthase and COX-2 expressions.

Preferential Peroxidase Activity of Prostaglandin Endoperoxide H Synthase for Lipid Peroxides

  • Yun, Seol-Ryung;Han, Su-Kyong;Song, In-Seok
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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    • pp.94-94
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    • 2001
  • Prostaglandin endoperoxide H synthase (PGHS) catalyzes the committed step in prostaglandins and thromboxane A$_2$-- oxygenation of arachidonic acid to the hydroperoxy endoperoxide PGG$_2$, followed by reduction PGG$_2$to the alcohol PGH$_2$. The two reactions by PGHS -- cyclooxygenase and peroxidase -- occur at distinct but structurally and functionally interconnected sites. The peroxidase reaction occurs at a heme-containing active site located near the protein surface. The cyclooxygenase reaction occurs in a hydrophobic channel in the core of the enzyme. Initially a peroxide reacts with the heme group, yielding Compound I and an alcohol derived from the oxidizing peroxide. Compound I next undergoes an intramolecular reduction by a single electron traveling from Tyr385 along the peptide chain to the proximal heme ligand, His388, and finally to the heme group. Following the binding of arachidonic acid, Tyr385 tyrosyl radical initiates the cyclooxygenase reaction by abstracting the 13-pro(5) hydrogen atom to give an arachidonyl radical, which sequentially reacts with two molecules of oxygen to yield PGG$_2$. In order to characterize PGHS peroxidase active site, we examined various lipid peroxides with purified recombinant ovine PGHS proteins and determined the rate constants. The results have shown that twenty-carbon unsaturated fatty acid hydroperoxides have similar efficiency in peroxidation by PGHS, irrespective of either the location of hydroperoxy group or the number of double bonds. It was also confirmed by the subsequent study with PGHS peroxidase active site mutants.

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Effects of the Aqueous Extract of Rehmanniae Radix Preparata on Lipopolysaccharide-induced Expressions of Cyclooxygenase-2 and Inducible Nitric Oxide Synthase in Mouse BV2 Microglial Cells

  • Jung, Chang-Young;Sung, Yun-Hee;Kim, Sung-Eun;Kim, Chang-Ju;Han, Seung-Ho;Lee, Choong-Yeol
    • 동의생리병리학회지
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    • 제20권4호
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    • pp.1051-1056
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    • 2006
  • Rehmanniae radix preparata is the root of Rehmanniae glutinosa Liboschitz var. purpurea Makino which has been classified into Scrophulariaceae. Rehmanniae radix preparata has been used for the treatment of diabetes, for the relief of the pain, and for the anti-oxidative action. In this study, the effect of the aqueous extract of Rehmanniae radix preparata on lipopolysaccharide-induced inflammation was investigated by using 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot, prostaglandin E2 immunoassay, and nitric oxide (NO) detection in mouse BV2 microglial cells. In the present results, the aqueous extract of Rehmanniae radix preparata suppressed prostaglandin E2 (PGE2) synthesis and nitric oxide production by inhibiting the lipopolysaccharide-stimulated expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) mRNA and protein in mouse BV2 cells. These results show that Rehmanniae radix preparata exerts anti-inflammatory effect probably by suppressing of COX-2 and iNOS expressions.

Chemoprevention of Colon Cancer

  • Wakabayashi, Keiji
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2003년도 추계학술대회
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    • pp.91-91
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    • 2003
  • Colon cancer is one of the most common malignancies in humans, and the search for effective chemopreventive agents is an important and urgent task. Expression levels of inflammation-related enzymes, cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) are elevated in colon cancers, and their products, prostaglandins and nitric oxide, are suggested to be involved in colon carcinogenesis.(omitted)

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식이의 Conjugated Linoleic Acid (CLA) Isomer가 DMH로 처리한 쥐에서 대장점막의 종양발생과 Cyclooxygenase-2 및 Protein Linase C 단백질 발현에 미치는 영향 (Effect of Dietary Conjugated Linoleic Acid (CLA) Isomers on Tumor Incidence and the Protein Expression of Cyclooxygenase-2 and Protein Kinase C in Colonae Mucosa of DMH-Treated Rats)

  • 박현서;전창수;윤정한
    • Journal of Nutrition and Health
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    • 제37권9호
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    • pp.763-770
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    • 2004
  • This study was designed to compare the anti-carcinogenic effect of conjugated linoleic acid isomers on tumor incidence, cell proliferation and the levels of thromboxane (TX) B$_2$, prostaglandin (PG) E$_2$ and 1,2-diacylglycerol (DAG), and the related enzyme expression of cyclooxygenase (COX)-2 and protein kinase C (PKC) in colonic mucosa of 1,2-dimethy- lhydrazine (DMH) -treated rats. One hundred eight male Sprague Dawley rats were randomly divided into 3 groups depending on the types of CLA isomers, i.e. control group (no CLA contained), c9t11 group (cis-9, trans-11 CLA contained), and t10c12 group (trans-10, cis-12 CLA contained). The experimental diet was composed of protein at 20%, carbohydrate at 56.2%, and fat at 14.5% including 1.0% CLA isomers by weight. The experimental diet was fed for 30 weeks with the initiation of intramuscular injection of DMH, which was injected twice a week for 6 weeks to give total dose of 180 mg per kg body weight. Two CLA isomers (c9, t11, t10, c12) significantly reduced tumor incidence and cell proliferation by reducing the protein expression of COX-2 and PKC, and the level of TXB$_2$, PGE$_2$, and DAG in colonic mucosa. However, there was no significant difference in anti-carcinogenic effect between c9t11-CLA and t10c12-CLA.

Triptolide Suppresses the Expression of Cyclooxygenase-2 Induced by Toll-Like Receptor 3 and 4 Agonists

  • Gu, Gyo-Jeong;Eom, Sang-Hoon;Min, In Soon;Youn, Hyung-Sun
    • 대한의생명과학회지
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    • 제19권2호
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    • pp.112-117
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    • 2013
  • Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs) and regulate the activation of innate immunity. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$, leading to the induction of inflammatory gene products such as cyclooxygenase-2 (COX-2). Triptolide (TP), a natural component of Tripterygium wilfordii Hook. F, has been used as folk remedies to treat many chronic diseases for many years. In the present report, we present biochemical evidence that TP inhibits the NF-${\kappa}B$ activation induced by polyriboinosinic polyribocytidylic acid (Poly[I:C], TLR3 agonist) and lipopolysaccharide (LPS, TLR4 agonist). TP also inhibits COX-2 expression induced by Poly[I:C] and LPS. These results suggest that TP can modulate the immune responses regulated by TLR3 and TLR4 signaling pathways.