• Title/Summary/Keyword: Cyclooxygenase-2

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An Increased Intracellular Calcium Ion Concentration in Response to Dimethyl Sulfoxide Correlates with Enhanced Expression of Recombinant Human Cyclooxygenase 1 in Stably Transfected Drosophila melanogaster S2 Cells (Dimethyl sulfoxide에 의한 세포내 칼슘이온 농도 증가가 안정적으로 형질 전환된 초파리 S2 세포에서 재조합 사람 cyclooxygenase 1의 발현에 미치는 영향)

  • Chang, Kyung Hwa;Park, Jong-Hwa;Kim, Do Hyung;Chung, Ha Young;HwangBo, Jeon;Lee, Hyun Ho;Lee, Hee-Young;Shon, Dong-Hwa;Kim, Wonyong;Chung, In Sik
    • KSBB Journal
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    • v.27 no.5
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    • pp.313-318
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    • 2012
  • Dimethyl sulfoxide (DMSO) increased the intracellular calcium ion concentration in stably transfected Drosophila melanogaster S2 cells expressing recombinant cyclooxygenase 1 (COX-1). DMSO did not increase the Drosophila NOS (dNOS) transcript level in calcium chelator-treated cells. Expression of recombinant COX-1 due to DMSO was diminished in cells treated with calcium chelators or channel blockers. Our results indicate that an increased intracellular calcium ion concentration due to DMSO is associated with up-regulation of the dNOS gene, leading to enhanced expression of COX-1.

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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    • v.3 no.1
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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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Anti-inflammatory Flavonoids: Modulators of Proinflammatory Gene Expression

  • Kim, Hyun-Pyo;Son, Kun-Ho;Chang, Hyeun-Wook;Kang, Sam-Sik
    • Natural Product Sciences
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    • v.10 no.1
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    • pp.1-10
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    • 2004
  • Plant flavonoids possess anti-inflammatory activity in vitro and in vivo. Although the action mechanisms are not fully understood, recent studies have clearly shown that certain flavonoids, especially flavone derivatives, express their anti-inflammatory activity at least in part by modulation of proinflammatory gene expression such as cyclooxygenase-2, inducible nitric oxide synthase and various cytokines. This review summarizes the recent findings of flavonoids modulating expression of proinflammatory molecules.

Recent Advances in Anti-inflammatory Flavonoid Research since 2004

  • Kim Hyun-Pyo
    • Biomolecules & Therapeutics
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    • v.14 no.1
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    • pp.11-18
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    • 2006
  • Certain flavonoids possess anti-inflammatory activity. Besides their antioxidative property, the cellular action mechanisms of flavonoids include an inhibition of arachidonate metabolizing enzymes such as cyclooxygenases and lipoxygenases, and a down-regulation of proinflammatory gene expression such as cyclooxygenase-2, inducible nitric oxide synthase and tumor necrosis factor-$\alpha$. In this review, the recent findings of anti-inflammatory flavonoid research since 2004 were summarized. And the cellular mechanisms on signal transduction pathways were also discussed.

Anti-Inflammatory Activity of Elsholtzia splendens

  • Kim, Dong-Wook;Son, Kun-Ho;Chang, Hyeun-Wook;Bae, Ki-Hwan;Kang, Sam-Sik;Kim, Hyun-Pyo
    • Archives of Pharmacal Research
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    • v.26 no.3
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    • pp.232-236
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    • 2003
  • Elsholtzia splendens Nakai has been used in North-East Asia as an ingredient of folk medicines for treating cough, headache and inflammation. The present investigation was carried out to establish its in vivo anti-inflammatory activity using several animal models of inflammation and pain. The 75% ethanol extract of the aerial part of E. splendens significantly inhibited mouse croton oil-induced, as well as arachidonic acid-induced, ear edema by oral administration (44.6% inhibition of croton oil-induced edema at 400 mg/kg). This plant material also showed significant inhibitory activity against the mouse ear edema induced by multiple treatment of phorbol ester for 3 days, which is an animal model of subchronic inflammation. In addition, E. splendens exhibited significant analgesic activity against mouse acetic acid-induced writhing (50% inhibition at 400 mg/kg), while indomethacin (5 mg/kg) demonstrated 95% inhibition. E. splendens ($5-100{\;}{\mu}g/mL$) significantly inhibited $PGE_2$ production by pre-induced cyclooxygenase-2 of lipopolysaccharide-treated RAW 264.7 cells, suggesting that cyclooxygenase-2 inhibition might be one of the cellular mechanisms of anti-inflammation.

A new Potential Anti-inflammatory Agent

  • Kim, Hee-Kee;Son, Kun-Ho;Chang, Hyeun-Wook;Kang, Sam-Sik;Kim, Hyun-Pyo
    • Archives of Pharmacal Research
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    • v.21 no.4
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    • pp.406-410
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    • 1998
  • Biflavonoid is one of unique classes of naturally-occurring bioflavonoids. Certain biflavonoids including amentoflavone were previously reported to have inhibitory effect on the group 11 phospholipase $A_2$ activity. Amentoflavone was also found to inhibit cyclooxygenase from guinea-pig epidermis without affecting lipoxygenase. In this study, anti-inflammatory and analgesic activities of amentoflavone were evaluated. When amentoflavone was administered intraperitoneally, it showed a potent anti-inflammatory activity as determined by amelioration of croton-oil induced mouse ear edema. It also showed a potent anti-inflammatory activity in the rat carrageenan paw edema model ($ED_{50}$=42 mg/kg) compared to the activity of prednisolone (35 mg/kg) and indomethacin (10 mg/kg). However, amentoflavone did not show a significant inhibitory activity against rat adjuvant-induced arthritis, a chronic inflammatory model. In addition, amentoflavone was found to possess a potent analgesic activity in the acetic acid writhing test ($ED_{50}$=9.6 mg/kg) compared to the activity of indomethacin (3.8 mg/kg). These results suggest that amentoflavone may be a potential lead for a new type of anti-inflammatory agents having dual inhibitory activity of group 11 phospholipase $A_2$ and cyclooxygenase.

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The Enhancement of Radiosensitivity by Celecoxib, Selective Cyclooxygenase-2 Inhibitor, on Human Cancer Cells Expressing Differential Levels of Cyclooxygenase-2 (선택적 Cyclooxygenase-2 억제제인 Celecoxib가 상이한 Cyclooxygenase-2 발현량을 가진 인간 암세포주들에 대하여 유도하는 방사선 감수성 증진 작용)

  • Pyo Hongryull;Shin You Keun;Kim Hyun Seok;Seong Jinsil;Suh Chang Ok;Kim Gwi Eon
    • Radiation Oncology Journal
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    • v.21 no.3
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    • pp.216-221
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    • 2003
  • Purpose: To investigate the modulation of radiosensitivity by celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on cancer cells over- and under-expressing COX-2. Materials and Methods: A clonogenic radiation survival analysis was performed on A549 human lung and MCF-7 human breast cancer cell lines incubated in both 1 and $10\%$ fetal bovine serum (FBS) containing media. The apoptosis in both cell lines was measured after treatment with radiation and/or celecoxib. Results: Celecoxib enhanced the radiation sensitivity of the A549 cells in the medium containing the $10\%$ FBS, with radiation enhancement ratios of 1.58 and 1.81 respectively, at surviving fractions of 0.1, with $30\muM\;and\;50\muM$ celecoxib. This enhanced radiosensitivity disappeared in the medium containing the $1\%$ FBS. Celecoxib did not change the radiation sensitivity of the MCF-7 cells in either media. The induction of apoptosis by celecoxib and radiation was not synergistic in either cell line. Conclwsion: Celecoxib, a selective COX-2 inhibitor, preferentially enhanced the effect of radiation on COX-2 over-expressing cancer cells compared to the cells with a low expression, and this effect disappeared on incubation of the cells during drug treatment in the medium with suboptimal serum concentration. Apoptosis did not appear to be the underlying mechanism of this radiation enhancement effect due to celecoxib on the A549 cells. These findings suggest radiosensitization by a selective COX-2 inhibitor is COX-2 dependent.

Paclitaxel Stimulates Cyclooxygenase-2 Expression via MAP Kinase Pathway in Rabbit Articular Chondrocytes

  • Im, Jeong-Hee;Kim, Song-Ja
    • Biomedical Science Letters
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    • v.15 no.2
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    • pp.141-146
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    • 2009
  • Paclitaxel, an antimicrotubule agent, binds to beta-tubulin in the microtubule and stabilizes the polymer, thereby repressing dynamic instability. Here, we have demonstrated that microtubule cytoskeletal architecture involved in regulation of the COX-2 expression in chondrocyte treated with paclitaxel. Paclitaxel enhanced COX-2 expression and prostaglandin E2 production, as indicated by the Western blot analysis, reverse transcriptase PCR(RT-PCR) and immunofluorescence staining, and $PGE_2$ assay, respectively. In our previous data have shown that paclitaxel treatment stimulated activation of ERK-1/2 and p38 kinase(Im et al., 2009). SB203580, an inhibitor of p38 kinase, blocked the induction of COX-2 expression by paclitaxel. Also PD98059, an inhibitor of ERK-1/2 kinase was blocked the induced COX-2 expression. These results indicate that activation of ERK-1/2 and p38 kinase is required for COX-2 expression induced by paclitaxel in rabbit articular chondrocytes.

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The Improving Effect of Paeoniae Radix on Dextran Sulfate Sodium-induced Colitis in Mice (Dextran Sulfate Sodium으로 유도된 궤양성 대장염에 대한 작약의 개선 효과)

  • Myung, Noh Yil
    • Korean Journal of Plant Resources
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    • v.31 no.4
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    • pp.275-282
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    • 2018
  • Paeoniae Radix has been used as a traditional medicine for various diseases including hepatic disease. However, the inhibitory effect of Paeoniae Radix on intestinal inflammation has not been fully understood yet. The aim of this study was to evaluate the effect of Paeoniae Radix on colitis induced by dextran sulfate sodium in mice. To investigate the protective effects of Paeoniae Radix, the colitis mice were induced by drinking water containing 5% dextran sulfate sodium for 7 days. Mice were randomized into groups receiving Paeoniae Radix (100 mg/kg), sulfasalazine (150 mg/kg) as a positive control, or water as a negative control. We evaluated the effects of Paeoniae Radix on clinical signs induced by dextran sulfate sodium, measuring weight loss, colon length, and disease activity index. Additionally, to find a possible explanation for the anti-inflammatory effects of Paeoniae Radix, we evaluated the effects of Paeoniae Radix on the interleukin-6 and cyclooxygenase-2 levels in colitis tissue. The results indicated that mice treated with dextran sulfate sodium showed measurable clinical signs, including weight loss and reduced colon length. However, Paeoniae Radix treatment significantly improved the weight loss and disease activity index as clinical symptoms. Moreover, Paeoniae Radix inhibited the interleukin-6 and cyclooxygenase-2 expression levels in colon tissues treated with dextran sulfate sodium. Taken together, the findings of this study suggest that Paeoniae Radix may be useful for treating intestinal inflammation, including ulcerative colitis.