• 제목/요약/키워드: Cyclooxygenase 2

검색결과 1,407건 처리시간 0.038초

Cyclooxygenase-2 Inhibitor from Evodia rutaecarpa

  • Kang, Sam-Sik;Kim, Ju-Sun;Son, Kun-Ho;Kim, Hyun-Pyo;Chang, Hyeun-Wook
    • Natural Product Sciences
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    • 제5권2호
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    • pp.65-69
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    • 1999
  • By bioassay guided fractionation followed by chromatographic separation of the MeOH extract from the fruit of Evodia rutaecarpa (Juss.) Benth. (Rutaceae), a new cyclooxygenase-2 inhibitor was isolated and identified as an alkaloid, rutaecarpine. Other alkaloids such as evodiamine and dehydroevodiamine together with limonoids were also isolated and characterized.

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The Potential Roles of Cyclooxygenase-2 and Matrix Metalloproteinase-9 in Cytomegalovirus-Infected Atherosclerotic Aorta and Coronary Artery

  • Eom, Yong-Bin
    • 대한의생명과학회지
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    • 제9권3호
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    • pp.123-131
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    • 2003
  • Inflammation appears to have a major role in the development of atherosclerosis. Cyclooxygenase-2 (COX-2) is involved in the inflammatory response via the generation of prostanoids that, in turn, are involved in the production of matrix metalloproteinases (MMPs). This study hypothesized that a vascular infection with cytomegalovirus (CMV) may induce a chronic inflammatory reaction and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases-9 (MMP-9). To confirm the hypothesis, the immunohistochemical stains for CMV late antigen, COX-2, MMP-9, macrophage, and T-lymphocyte were performed on CMV-infected atherosclerotic lesions. The immunoreactivity for COX-2 and MMP-9 was evident in all cases of atherosclerosis along with plaques, mainly in macrophages/foamy cells, intimal and medial smooth muscle cells, and endothelial cells of the intima. Within the intima, the increased immunoreactivity for COX-2 and MMP-9 was colocalized to the area stained with CMV late antigen. Sections from control specimens showed no immunoreactivity for CMV late antigen, COX-2 and MMP-9. These data seem to support the hypothesis that CMV may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis.

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Inhibitory Effects of Herbal Extracts on Cyclooxygenase Activity of Prostaglandin $H_2$ Synthase from Sheep Seminal Vesicle

  • Min, Kyung-Rak;Kim, Young-Ki;Kang, Seh-Hoon;Mar, Woong-Chon;Lee, Kyong-Soon;Ro, Jae-Seup;Lee, Seung-Ho;Kim, Young-Soo
    • Natural Product Sciences
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    • 제2권1호
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    • pp.56-74
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    • 1996
  • Prostaglandin $H_2$ synthase is the pharmacological target site of nonsteroidal antiinflammatory drugs. Inhibitory effects on cyclooxygenase activity of the synthase by extracts prepared from herbal medicines and wild plants in Korea have been estimated. Sixteen species out of 612 species exhibited more than 50% of inhibition on the enzyme activity. The active extracts prepared from Carex humilis, Celastrus orbiculatus, Eugenia caryophyllata, Gleditsia japonica var. koraiensis, Glycyrrhiza grabra, Glycyrrhiza uralensis, Gyrophora exculenta, Lespedeza maximowiczii, Morus alba, Persicaria conspicua, Prunus salicina, pterocarya stenoptera, Rheum undulatum, Vitis amurensis, and Vitis coignetiae have been sequentially washed with methylene chloride, ethyl acetate, n-butanol. Among the solvent fractions of the active herbal extracts, ethyl acetate fraction of Carex humilis exhibited the highest inhibitory effect on the cyclooxygenase activity of prostaglandin $H_2$ synthase.

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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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Inhibition of cyclooxygenase-2 expression by Caffeoyl-4-dihydrocaffeoyl quinic acid in macrophages

  • Chung, Yung-Chul;Choi, Chul-Yung;Kim, Ji-Young;Chun, Hyo-Kon;Gho, Young-Hee;Jeong, Hye-Gwang
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.113.2-113.2
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    • 2003
  • Inducible cyclooxygenase-2 (COX-2) has been implicated in the processes of inflammation and carcinogenesis. Thus, the potential COX-2 inhibitors have been considered as anti-inflammatory or cancer chemopreventive agents. In this study, we investigated the effect of Caffeoyl-4-dihydrocaffeoyl quinic acid (CDCQ) isolated from Salicornia herbacea on the expression of cyclooxygenase (COX-2) in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. When CDCQ was treated with LPS, the prostaglandin $E_2$ production and COX-2 gene expression induced by LPS were markedly reduced in a dose-dependent manner. (omitted)

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Study on the Action by PAF on IL-1 Modulation in Alveolar Macrophages: Involvement of Endogenous Arachidonate Metabolites and Intracellular $Ca^{++}$ Mobilization

  • Lee, Ji-Hee;Kim, Won-Ki;Hah, Jong-Sik
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권2호
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    • pp.241-249
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    • 1998
  • Platelet-activating factor(PAF) enhanced interleukin-1(IL-1) activity by the interaction with a specific receptor in rat alveolar macrophages. In this study, we investigated the role of endogenous arachidonate metabolites and intracellular calcium mobilization in the PAF-induced IL-1 activity. Alveolar macrophages were preincubated with 5-lipoxygenase and cyclooxygenase inhibitors 30 min before the addition of PAF and lipopolysaccharide(LPS). After 24h culture, IL-1 activity was measured in the supernate of sample using the thymocyte proliferation assay. Inhibition of 5-lipoxygenase by nordihydroguaiaretic acid and AA-861 completely blocked the PAF-induced enhancement of IL-1 activity with $IC_{50}\;of\;2\;{\mu}M\;and\;5\;{\mu}M$, respectively. In contrast, the inhibition of cyclooxygenase pathway by indomethacin and ibuprofen resulted in the potentiation in PAF-induced IL-1 activity with maximal effect at $1\;{\mu}M\;and\;5\;{\mu}M$, respectively. In addition, leukotriene $B_4$ and prostaglandin $E_2$ production were observed in PAF-stimulated alveolar macrophage culture. As could be expected, 5-lipoxygenase and cyclooxygenase inhibitors abolished PAF- stimulated leukotriene $B_4$ and prostaglandin $E_2$ production, respectively. The effects of PAF on intracellular calcium mobilization in alveolar macrophages were evaluated using the calcium-sensitive dye fura-2 at the single cell level. PAF at any dose between $10^{-16}\;and\;10^{-8}$ M did not increase intracellular calcium. Furthermore, there was no effective change of intracellular calcium level when PAF was added to alveolar macrophages in the presence of LPS or LPS+LTB4, and 4, 24 and 48h after treatment of these stimulants. Together, the results indicate that IL-1 activity induced by PAF is differently regulated through subsequent induction of endogenous 5-lipoxygenase and cyclooxygenase pathways, but not dependent on calcium signalling pathway.

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ET-18-O-$CH_3$ INDUCED APOPTOSIS IN H-RAS TRANSFORMED HUMAN BREAST EPITHELIAL CELLS THROUGH UP-REGULATION OF CYCLOOXYGENASE-2

  • Na, Hye-Kyung;Surh, Young-Joon
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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    • pp.80-80
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    • 2002
  • Cyclooxygenase-2 (COX-2) is an inducible enzyme expressed in response to a variety of cytokines. The presence of oncogenic ras has been associated with sustained induction of COX-2, which confers resistance to apoptosis. Contrary to the above notion, we found that MCF10A-ras cells treated with an anti-tumor agent, ET-18-O-$CH_3$, underwent apoptosis as revealed by proteolytic cleavage of poly(ADP-ribose)polymerase, pro-caspase 3 activity, and TUNEL staining, while the same treatment caused an increased expression of COX-2 as well as the elevated production of prostaglandin E$_2$(PGE$_2$).(omitted)

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로즈마리 추출물의 cyclooxygenase (COX) 효소 및 유전자 발현에 미치는 영향 (Evaluation of cyclooxygenase (COX) inhibition in rosemary extract)

  • 이세희;박수연;김경진;김선우;정양훈;김지연
    • Journal of Applied Biological Chemistry
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    • 제66권
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    • pp.114-121
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    • 2023
  • 선택적 cyclooxygenase (COX)-2 억제제는 기존의 비스테로이드성 소염제의 위장 부작용을 줄일 수 있는 새로운 대체제이다. 하지만, 최근 혈전을 일으켜 심혈관 질환의 위험을 증가시킨다는 보고가 있다. 따라서 본 연구에서는 유효성분인 ursolic acid를 각각 40, 50%로 극대화한 로즈마리 추출물(RE)의 항염증 효과와 이에 따른 심혈관 부작용의 안전성을 확인하였다. RE의 COX 효소 활성 저해 평가 결과 40, 50% RE는 100 ㎍/mL에서 양성 대조군인 celecoxib 및 rofecoxib와 비슷한 COX-2 저해 활성을 보였고, COX-1 저해 활성은 미미하였다. 이후 Lipopoly-saccharide (LPS)를 조건에 따라 처리한 RAW 264.7 세포에 40, 50% RE 1 ㎍/mL를 처리하여 COX-2, COX-1 유전자 발현, 세포 배양액의 prostaglandin E2 (PGE2), thromboxane B2 (TXB2) 농도를 확인하였다. 실험 결과 COX-2 유전자 발현은 40% RE가 LPS를 24시간 후처리한 조건에서 감소하였고, 40, 50% RE는 COX-1 유전자 발현 및 PGE2, TXB2 농도에는 유의한 영향을 주지 않는 것으로 확인되었다. 따라서 RE는 혈전 생성에 관여하는 prostaglandins의 균형에 영향을 주지 않아 심혈관 혈전 생성의 위험성이 적을 것으로 사료된다.