• 제목/요약/키워드: Cyclooxygenase I

검색결과 673건 처리시간 0.031초

Asiaticoside가 RAW 264,7 세포에서 Inducible nitric oxide synthase와 Cyclooxygenase-2에 미치는 항염증 작용에 관한 연구 (Anti-inflammatory Effects of Asiaticoside on Inducible Nitric Oxide Synthase and Cyclooxygenase-2 in RAW 264.7 Cell Line)

  • 주상섭;배옥남;정진호
    • Toxicological Research
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    • 제19권1호
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    • pp.33-37
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    • 2003
  • Asiaticoside has been tested for the ability as an anti-inflammatory drug using lipopolysaccharide (LPS)-stimulated macrophage cell line (RAW 264.7 cell). LPS treatment induced dramatically inducible nitric oxide synthase (iNOS) in RAW cells. However, asiaticoside inhibited LPS-stimulated iNOS induction in a concentration-dependent manner. Especially, higher concentrations (>50 $\mu\textrm{M}$) of asiaticoside completely blocked iNOS induction. In addition, LPS-stimulated expression of inducible cyclooxygenase (COX-2) and interleukin-1 $\alpha$ (IL-1 $\alpha$) was inhibited by asiaticoside treatment. Asiaticoside up to 50 $\mu\textrm{M}$ still required to inhibit COX-2 and IL-1 $\alpha$ induced by LPS. Consistent with these findings, treatment with asiaticoside suppressed do novo synthesis and cellular accumulation of prostaglandin $E_2$ to a lesser extent, suggesting that asiaticoside blocked the induction as well as the activity of COX-2 These results suggest the possibility that asiaticoside may be effective therapeutic agents for septic shock and other inflammatory diseases.

Detection of Antiinflammatory Agents from Natural Products as Inhibitors of Cyclooxygenase I and II

  • Lee, Dong-Hee;Kang, Sam-Sik;Chang, Il-Moo;Mar, Woong-Chon
    • Natural Product Sciences
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    • 제3권1호
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    • pp.19-28
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    • 1997
  • Constitutive cyclooxygenase (COX-I) is present in cells under physiological conditions, whereas inducible cyclooxygenase (COX-II) is induced by some cytokines, mitogens, and endotoxin presumably in pathological conditions such as inflammation. We have evaluated the inhibitory effects of solvent fractionated extracts of natural products on the activities of COX-I and COX-II. Oxygen uptake COX assay was performed, as a primary screening from the tissue extracts of bovine seminal vesicles (BSV), by monitoring the initial rate of oxygen uptake using an oxygen electrode. Additionally, we evaluated plant extracts for the inhibitory effects of COX-I (in HEL cells) and COX-II (in lipopolysaccharide activated J774A.1 macrophages) using thin layer chromatography of prostanoids produced from $^{14}C-labelled$ arachidonic acid (AA). The use of such models of COX-I and COX-II assay will lead to the identification of specific inhibitors of cyclooxygenases with presumably less side effects than present therapies. Inhibitory effects of 50 kinds of plant extracts on the COX-I and COX-II activities were determined and the active fractions were found in the ethyl acetate fractions of Dryopteris crassirhizoma (roots), Amomum cardamomum (roots), Triticum aestivum (seeds), Perilla sikokiana (leaves), Anemarrhena asphodeloides (roots). Especially, the ethyl acetate fraction of Dryopteris crassirhizoma (roots), which exhibited the strong inhibition against BSV COX $(IC_{50},\;65.4\;{\mu}g/ml)$, COX-I $(IC_{50},\;8.5\;{\mu}g/ml)$, and COX-II $(IC_{50},\;17.2\;{\mu}g/ml)$, is under investigation to isolate active principles using activity-guided fractionation method.

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구인(蚯蚓)이 흰쥐의 뇌혈류역학 변화에 미치는 효과 (Effects of Lumbricus on the Change of Cerebral Hemodynamics in Rats)

  • 이정우;권영달;염승룡;송용선
    • 한방재활의학과학회지
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    • 제18권1호
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    • pp.65-74
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    • 2008
  • Objectives : This experimental study was designed to investigate the effects of Lumbricus extract (LE) on the changes in regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats, and further to determine the mechanism of action of LE. Methods : The changes of rCBF were observed by Laser-Doppler flowmetry (LDF) and the changes of MABP were recorded by a data acquisition system assembled with MacLab and Macintosh. Results : LE significantly increased rCBF in a high dosage(10.0 mg/kg, i.p), but MABP was somewhat increased as compared with baseline. This result suggests that LE significantly increased rCBF by dilating pial arterial diameter. Increase of LE-induced rCBF was significantly inhibited by pretreatment with indomethacin (1 mg/kg, i.p), an inhibitor of cyclooxygenase, but was not significantly inhibited by pretreatment with methylene blue ($10{\mu}g/kg$, i.p), an inhibitor of guanylate cyclase. Conclusions : LE increased rCBF by dilating pial arterial diameter, and the action of this response was mediated by cyclooxygenase.

Methanol Extracts of Stewartia koreana Inhibit Cyclooxygenase-2 (COX-2) and Inducible Nitric Oxide Synthase (iNOS) Gene Expression by Blocking NF-κB Transactivation in LPS-activated RAW 264.7 Cells

  • Lee, Tae Hoon;Kwak, Han Bok;Kim, Hong-Hee;Lee, Zang Hee;Chung, Dae Kyun;Baek, Nam-In;Kim, Jiyoung
    • Molecules and Cells
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    • 제23권3호
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    • pp.398-404
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    • 2007
  • Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are involved in various pathophysiological processes such as inflammation and carcinogenesis. In a search for inhibitors of COX-2 and iNOS production we found that extracts of Stewartia koreana strongly inhibited NO and $PGE_2$ production in LPS-treated macrophage RAW 264.7 cells. We have now shown that the mRNA and protein levels of iNOS and COX-2 are reduced by the Stewartia koreana extract (SKE). SKE inhibited expression of an NF-${\kappa}B$ reporter gene in response to LPS, and gel mobility shift assays revealed that SKE reduced NF-${\kappa}B$ DNA-binding activity. The extract also inhibited LPS-induced phosphorylation of $I{\kappa}B-{\alpha}$ and nuclear translocation of p65. Administration of the extract reduced the symptoms of arthritis in a collagen-induced arthritic mouse model. These results indicate that Stewartia extracts contain potentially useful agents for preventing and treating inflammatory diseases.

천마반하탕이 뇌허혈로 인한 뇌혈류역학적 변동에 미치는 영향 (Effect of Cheonmabanhwa-Tang on the Changes in Cerebral Hemodynamics in Cerebral Ischemia of Rats)

  • 양기호;윤대영;정현우
    • 동의생리병리학회지
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    • 제18권3호
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    • pp.783-788
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    • 2004
  • Cheonmabanhwa- Tang (CBT) has been used in the Oriental Medicine for many centuries as a therapeutic agent for dizziness due to Poong-Dam, We reported that CBT had effects on the cerebral hemodynamics [regional cerebral blood flow (rCBF), pial arterial diameter (PAD), and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats. Therefor we designed to determine the mechanism of action of CBT. The changes of rCBF and MABP were determinated by laser-Doppler flowmetry(LDF), and the change of PAD was determinated by video-microscopy. The results were as follows: The CBT-induced increase in rCBF was significnatly inhibited by pretreatment with indomethacin (IDN, 1 ㎎/㎏, i.p.), an inhibitor of cyclooxygenase, or methylene blue (MTB, 10 ㎍/㎏, i.p.), an inhibitor of guanylate cyclase. The CBT-induced increase in PAD was also significantly inhibited by pretreatment with IDN or MTB. The CBT-induced increase in MABP was also significantly inhibited by pretreatment with IDN or MTB. In conclusion, it is suggested that CBT causes a diverse effect on cerebral hemodynamics via mediation of cyclooxygenase and guanylate cyclase.

사물탕합죽력(四物湯合竹瀝)이 국소 뇌혈류량과 평균 혈압에 미치는 실험적 연구 (Experimental Study of Samul-tang Extract and Bambusae caulis in liquamen on the Regional Cerebral Blood Flow and Mean Arterial Blood Pressure in Normal Rats)

  • 조영림;정현우
    • 동의생리병리학회지
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    • 제21권6호
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    • pp.1394-1400
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    • 2007
  • This study was designed to investigate the effects of Samul-tang Extract and Bambusae caulis in liquamen(SEB) on the changes in regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats. The results were as follows ; SBE significantly increased rCBF in a dose-dependent manner, and increased MABP in a dose-dependent manner. This result suggests that SBE significantly increased rCBF by dilating pial arterial diameter. Increase of SBE-induced rCBF was significantly inhibited by pretreatment with indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase and increase of SBE-induced rCBF was inhibited by pretreatment with methylene blue ($10\;{\mu}g/kg$, i.p.), an inhibitor of guanylate cyclase. Increase of SBE-induced MABP was significantly increased by pretreatment with methylene blue but increase of SBE-induced MABP was decreased by pretreatment with indomethacin. These results suggested that the action of SBE was mediated by cyclooxygenase.

Parthenolide Inhibits Ovalbumin-Induced cyclooxygenase-2 and Inducible Nitric Oxide Synthase Expression

  • Youn, Hyung-Sun
    • 대한의생명과학회지
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    • 제18권3호
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    • pp.319-323
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    • 2012
  • In recent years, egg allergy has been raised as the most prevalent food hypersensitivity in the pediatric population. One of the major egg allergens is ovalbumin (OVA) which is the major protein in egg white, comprising 54% of its total protein content. Parthenolide isolated from Tanacetum partheniumb has been used to treat many chronic diseases for many years. In the present report, we present biochemical evidence that parthenolide inhibits the nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activation induced by OVA. Parthenolide also inhibits OVA-induced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression. These data suggest new approaches for the efficient alleviation of the allergic symptoms.

Cyclooxygenase-2 as a Molecular Target for Cancer Chemopreventive Agents

  • Surh, Young-Joon
    • Toxicological Research
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    • 제17권
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    • pp.89-96
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    • 2001
  • Recently, considerable attention has been focused on the role of cyclooxygenase-2 (COX-2) in the carcinogenesis as well as in inflammation. Improperly overexpressed COX-2 has been observed in many types of human cancers and transformed cells in culture. Thus, it is conceivable that targeted inhibition of abnormally or improperly up-regulated COX-2 provides one of the most effective and promising strategies for cancer prevention. A ubiquitous eukaryotic transcription factor, NF-kB is considered to be involved in regulation of COX-2 expression. Furthermore, extracellular-regulated protein kinase and p38 mitogen-activated protein (MAP) kinase appear to be key elements of the intracellular signaling cascades involved in NF-kB activation in response to a wide array of external stimuli. Certain chemopreventive phytochemicals suppress activation of NF-kB by blocking one or more of the MAP kinases, which may contribute to their inhibitory effects on COX-2 induction. One of the plausible mechanisms by which chemopreventive phytochemicals inhibit NF-kB activation involves suppression of degradation of the inhibitory unit I kB, which hampers subsequent translocation of p65, the functionally active subunit of NF-kB.

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Isoliquiritigenin Inhibits Ovalbumin-induced Cyclooxygenase-2 and Inducible Nitric Oxide Synthase Expression

  • Lim, Se Jin;Youn, Hyung-Sun
    • 대한의생명과학회지
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    • 제19권3호
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    • pp.270-274
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    • 2013
  • Egg allergy has been raised as the most prevalent food hypersensitivity in children. Ovalbumin (OVA), which is one of the major egg allergens, is the major protein in egg white. Isoliquiritigenin (ILG) is an active component present in licorice and has been used to treat many chronic diseases for many years. In this study, we present biochemical evidence that ILG inhibits OVA-induced nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activation. ILG also inhibits OVA-induced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression. These data suggest that ILG has anti-allergy effects.