scholarly journals Flavocoxid Inhibits Phospholipase A2, Peroxidase Moieties of the Cyclooxygenases (COX), and 5-Lipoxygenase, Modifies COX-2 Gene Expression, and Acts as an Antioxidant

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Bruce P. Burnett ◽  
Alessandra Bitto ◽  
Domenica Altavilla ◽  
Francesco Squadrito ◽  
Robert M. Levy ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phospholipase A2 ◽  
Peritoneal Macrophages ◽  
Mechanisms Of Action ◽  
Enzyme Assays ◽  
Molecular Pathways ◽  
Oxygen Species ◽  
Cox 2 ◽  
Cox 1

The multiple mechanisms of action for flavocoxid relating to arachidonic acid (AA) formation and metabolism were studiedin vitro. Flavocoxid titrated into rat peritoneal macrophage cultures inhibited cellular phospholipase A2 (PLA2) (IC50= 60 μg/mL). Inin vitroenzyme assays, flavocoxid showed little anti-cyclooxygenase (CO) activity on COX-1/-2 enzymes, but inhibited the COX-1 (IC50= 12.3) and COX-2 (IC50= 11.3 μg/mL) peroxidase (PO) moieties as well as 5-lipoxygenase (5-LOX) (IC50= 110 μg/mL). No detectable 5-LOX inhibition was found for multiple traditional and COX-2 selective NSAIDs. Flavocoxid also exhibited strong and varied antioxidant capacitiesin vitroand decreased nitrite levels (IC50= 38 μg/mL) in rat peritoneal macrophages. Finally, in contrast to celecoxib and ibuprofen, which upregulated thecox-2 gene, flavocoxid strongly decreased expression. This work suggests that clinically favourable effects of flavocoxid for management of osteoarthritis (OA) are achieved by simultaneous modification of multiple molecular pathways relating to AA metabolism, oxidative induction of inflammation, and neutralization of reactive oxygen species (ROS).

Regulation of prostaglandin biosynthesis in vivo by glutathione

1998 ◽  
Vol 274 (2) ◽  
pp. R294-R302 ◽  
Author(s):  
Alon Margalit ◽  
Scott D. Hauser ◽  
Ben S. Zweifel ◽  
Melissa A. Anderson ◽  
Peter C. Isakson
Keyword(s):  
Reduced Glutathione ◽  
Intraperitoneal Administration ◽  
Peritoneal Macrophages ◽  
Urate Crystal ◽  
Cox 2 ◽  
Cox 1 ◽  
Urate Crystals

Intraperitoneal administration of urate crystals to mice reduced subsequent macrophage conversion of arachidonic acid (AA) to prostaglandins (PGs) and 12-hydroxyeicosatetraenoic acid for up to 6 h. In contrast, levels of 12-hydroxyheptadecatrienoic acid (12-HHT) were markedly elevated. This metabolic profile was previously observed in vitro when recombinant cyclooxygenase (COX) enzymes were incubated with reduced glutathione (GSH). Analysis of peritoneal GSH levels revealed a fivefold elevation after urate crystal administration. The GSH synthesis inhibitorl-buthionine-[ S, R]-sulfoximine partially reversed the urate crystal effect on both GSH elevation and PG synthesis. Moreover, addition of exogenous GSH to isolated peritoneal macrophages shifted AA metabolism from PGs to 12-HHT. Urate crystal administration reduced COX-1, but induced COX-2 expression in peritoneal cells. The reduction of COX-1 may contribute to the attenuation of PG synthesis after 1 and 2 h, but PG synthesis remained inhibited up to 6 h, when COX-2 levels were high. Overall, our results indicate that elevated GSH levels inhibit PG production in this model and provide in vivo evidence for the role of GSH in the regulation of PG biosynthesis.

scholarly journals Zymosan-induced glycerylprostaglandin and prostaglandin synthesis in resident peritoneal macrophages: roles of cyclo-oxygenase-1 and -2

2006 ◽  
Vol 399 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Carol A. Rouzer ◽  
Susanne Tranguch ◽  
Haibin Wang ◽  
Hao Zhang ◽  
Sudhansu K. Dey ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Peritoneal Macrophages ◽  
Prostaglandin Synthesis ◽  
Wild Type ◽  
Cytosolic Phospholipase ◽  
Cytosolic Phospholipase A2α ◽  
Cox 2 ◽  
Cox 1 ◽  
Exogenous Substrates

COX [cyclo-oxygenase; PG (prostaglandin) G/H synthase] oxygenates AA (arachidonic acid) and 2-AG (2-arachidonylglycerol) to endoperoxides that are converted into PGs and PG-Gs (glycerylprostaglandins) respectively. In vitro, 2-AG is a selective substrate for COX-2, but in zymosan-stimulated peritoneal macrophages, PG-G synthesis is not sensitive to selective COX-2 inhibition. This suggests that COX-1 oxygenates 2-AG, so studies were carried out to identify enzymes involved in zymosan-dependent PG-G and PG synthesis. When macrophages from COX-1−/− or COX-2−/− mice were treated with zymosan, 20–25% and 10–15% of the PG and PG-G synthesis observed in wild-type cells respectively was COX-2 dependent. When exogenous AA and 2-AG were supplied to COX-2−/− macrophages, PG and PG-G synthesis was reduced as compared with wild-type cells. In contrast, when exogenous substrates were provided to COX-1−/− macrophages, PG-G but not PG synthesis was reduced. Product synthesis also was evaluated in macrophages from cPLA2α (cytosolic phospholipase A2α)−/− mice, in which zymosan-induced PG synthesis was markedly reduced, and PG-G synthesis was increased approx. 2-fold. These studies confirm that peritoneal macrophages synthesize PG-Gs in response to zymosan, but that this process is primarily COX-1-dependent, as is the synthesis of PGs. They also indicate that the 2-AG and AA used for PG-G and PG synthesis respectively are derived from independent pathways.

scholarly journals Phospholipase A2 and Cyclooxygenase Gene Expression in Human Preimplantation Embryos

2002 ◽  
Vol 87 (6) ◽  
pp. 2629-2634 ◽  
Author(s):  
Hongbo Wang ◽  
Yan Wen ◽  
Stephen Mooney ◽  
Barry Behr ◽  
Mary Lake Polan
Keyword(s):  
Gene Expression ◽  
Embryonic Development ◽  
Phospholipase A2 ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Cox 2 ◽  
Human Preimplantation Embryos ◽  
Early Human ◽  
Cox 1

Phospholipase A2 (PLA2) and cyclooxygenase (COX) are two key enzymes in PG synthesis; the latter has two forms, COX-1 and COX-2. mRNA was extracted from single preimplantation embryos and examined for PLA2, COX-1, and COX-2 gene expression by RT-PCR to investigate whether PLA2 and COX genes are expressed in human preimplantation conceptuses from zygote to blastocyst stage and to compare COX-1 and COX-2 gene expression within the same stage of embryonic development. Expression of PLA2, COX-1, and COX-2 was detected in 48, 37, and 45%, respectively, of total embryos examined. COX-1 was expressed in approximately 66% of early human preimplantation embryos from zygote to two-cell stage, whereas COX-2 was expressed in about 58% of later stage embryos from eight-cell to blastocyst stage (P < 0.05). Furthermore, COX-2 mRNA and protein were localized to trophectoderm in blastocyst stage embryos. In conclusion, PLA2, COX-1, and COX-2 are expressed during early human embryonic development and may contribute to the production of PGs such as PGE2 in human embryogenesis. COX-1 and COX-2 are differentially expressed, with COX-2 being primarily expressed by trophectoderm in late-stage human preimplantation embryos, which may promote embryonic differentiation and implantation.

scholarly journals Effects of Ubiquinol-10 on MicroRNA-146a Expression In Vitro and In Vivo

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Constance Schmelzer ◽  
Mitsuaki Kitano ◽  
Gerald Rimbach ◽  
Petra Niklowitz ◽  
Thomas Menke ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reactive Oxygen Species ◽  
Biological Processes ◽  
Oxygen Species ◽  
Moderate Reduction ◽  
Suppression Of Gene Expression ◽  
Fine Tune ◽  
Dependent Pathway

MicroRNAs (miRs) are involved in key biological processes via suppression of gene expression at posttranscriptional levels. According to their superior functions, subtle modulation of miR expression by certain compounds or nutrients is desirable under particular conditions. Bacterial lipopolysaccharide (LPS) induces a reactive oxygen species-/NF-κB-dependent pathway which increases the expression of the anti-inflammatory miR-146a. We hypothesized that this induction could be modulated by the antioxidant ubiquinol-10. Preincubation of human monocytic THP-1 cells with ubiquinol-10 reduced the LPS-induced expression level of miR-146a to 78.9±13.22%. In liver samples of mice injected with LPS, supplementation with ubiquinol-10 leads to a reduction of LPS-induced miR-146a expression to 78.12±21.25%. From these consistent in vitro and in vivo data, we conclude that ubiquinol-10 may fine-tune the inflammatory response via moderate reduction of miR-146a expression.

Cyclooxygenase-2 plays a significant role in regulating the tone of the fetal lamb ductus arteriosus

1999 ◽  
Vol 276 (3) ◽  
pp. R913-R921 ◽  
Author(s):  
Ronald I. Clyman ◽  
Pierre Hardy ◽  
Nahid Waleh ◽  
Yao Qi Chen ◽  
Françoise Mauray ◽  
...  
Keyword(s):  
Significant Role ◽  
Ductus Arteriosus ◽  
Late Gestation ◽  
Relative Contribution ◽  
Cox Inhibitor ◽  
Fetal Lamb ◽  
Cox 2 ◽  
Cox 2 Inhibitors ◽  
Cox 1

Nonselective cyclooxygenase (COX) inhibitors are potent tocolytic agents but have adverse effects on the fetal ductus arteriosus. We hypothesized that COX-2 inhibitors may not affect the ductus if the predominant COX isoform is COX-1. To examine this hypothesis, we used ductus arteriosus obtained from late-gestation fetal lambs. In contrast to our hypothesis, fetal lamb ductus arteriosus expressed both COX-1- and COX-2-immunoreactive protein (by Western analysis). Although COX-1 was found in both endothelial and smooth muscle cells, COX-2 was found only in the endothelial cells lining the ductus lumen (by immunohistochemistry). The relative contribution of COX-1 and COX-2 to PGE2 synthesis was consistent with the immunohistochemical results: in the intact ductus, PGE2 formation was catalyzed by both COX-1 and COX-2 in equivalent proportions; in the endothelium-denuded ductus, COX-2 no longer played a significant role in PGE2 synthesis. NS-398, a selective inhibitor of COX-2, was 66% as effective as the selective COX-1 inhibitor valeryl salicylate and the nonselective COX inhibitor indomethacin in causing contraction of the ductus in vitro. At this time, caution should be used when recommending COX-2 inhibitors for use in pregnant women.

scholarly journals Aktivitas Antiinflamasi Keladi Belau (Caladium bicolor (W. Ait) Vent.) Terhadap Enzim Siklooksigenase (COX) Secara In Vitro

2016 ◽  
Vol 3 ◽  
pp. 331-334
Author(s):  
Nisa Naspiah ◽  
Yoppi Iskandar ◽  
Moelyono M W Moelyono M W ◽  
Febrina Mahmudah ◽  
Lia Puspitasari
Keyword(s):  
Cox 2 ◽  
Cox 1

Penelitian mengenai aktivitas antiinflamasi keladi belau (Caladium bicolor (W. Ait) Vent.) terhadap enzim siklooksigenase (COX) secara in vitro telah dilakukan. Aktivitas antiinflamasi secara in vitro terhadap enzim COX ditentukan dengan menggunakan metode TMPD (N,N,N’,N’-tetrametil-p-fenilendiamin) secara spektrofotometri. Enzim COX yang diuji meliputi enzim COX-1 dan COX-2. Berdasarkan hasil pengujian diketahui ekstrak batang keladi belau mempunyai aktivitas antiinflamasi dengan nilai IC50 sebesar 250,66 ppm terhadap COX-1 dan 255,27 ppm terhadap COX-2. Hasil pengujian menunjukkan bahwa ekstrak tersebut lebih banyak menghambat enzim COX-1.

Effects of phenacetin and its metabolite p-phenetidine on COX-1 and COX-2 activities and expression in vitro

2003 ◽  
Vol 110 (5-6) ◽  
pp. 299-303 ◽  
Author(s):  
Esko Kankuri ◽  
Erkka Solatunturi ◽  
Heikki Vapaatalo
Keyword(s):  
Cox 2 ◽  
Cox 1

Abstract 066: Cyclooxygenase-depended Signaling Via Thromboxane Prostanoid Receptors Mediates Endothelin-i Induced Ros Generation In Mesenteric Resistance Vessels From Mice Infused With Angiotensin Ii

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Christopher S Wilcox ◽  
Cheng Wang ◽  
Dan Wang
Keyword(s):  
Reactive Oxygen Species ◽  
Angiotensin Ii ◽  
Ros Generation ◽  
Oxygen Species ◽  
Ang Ii ◽  
Wild Type ◽  
Prostanoid Receptors ◽  
Resistance Vessels ◽  
Cox 2 ◽  
Cox 1

Background: Angiotensin II (Ang II) increases reactive oxygen species (ROS) and contractions to thromboxane and endothelin-1 (ET-1). Therefore, we tested the hypothesis that cyclooxygenase (COX) and/or thromboxane-prostanoid receptors (TP-Rs) mediate enhanced ROS generations with ET-1 in Ang II-infused mice. Methods: ROS was assessed by urinary 8-isoprotane(8-Iso) excretion and ethedium : dihydroetheldium (DHE) in mesenteric resistance arterioles (MRAs) from wild type (+/+) and littermate COX-1 -/- or TP-R -/- mice infused with vehicle or angiotensin II (Ang II, 400 ng/kg/min for 14 days) (n=6/ group, mean ±SEM). Results: Ang II infusion increased excretion (ng/mg creatine) of TxB 2 (1.3±0.1±1.0±0.1 in COX-1 +/+ mice and 1.9±0.1 vs 1.2±0.1 in TP-R +/+ mice, all P<0.05) and 8-Iso (2.1±0.2 vs 1.4±0.1 in COX-1 +/+ mice and 2.2±0.1 vs 1.4±0.2 in TP-R +/+ mice, all P<0.05) but not in COX-1 -/- or TP-R -/- mice. Ang II enhanced ROS generation (Δunit) with 10 -7 M ET-1 in MRAs from both +/+ mouse genotypes (1.7±0.2 vs 0.1±0.1 in COX-1 +/+ mice and 3.2±0.3 vs 0.1±0.1 in TP-R +/+ mice, all P<0.01). However, this increase in ROS was fully prevented in TP-R-/- mouse vessels (0.3±0.2 vs 0.2±0.1, NS) and in COX-1 +/+ mouse vessels after combined blockade of COX-1( 10 -5 M SC-560) and -2 (paracoxib 10 -5 M) (0.2±0.1 vs 0.1±0.1, NS) and in COX-1 -/- mouse vessels after paracoxib (0.2±0.1 vs 0.2±0.2, NS). Increased ROS generation was only partially prevented in COX-1 -/- mouse vessels (0.5±0.1 vs 0.2±0.2, P<0.05) or in COX-1 +/+ mouse vessels after blockade of COX-1 ( 0.7±0.1 vs 0.1±0.1, NS) or COX-2 (1.0±0.1 vs 0.1±0.1,P<0.05). Conclusions: Increased ROS generation with ET-1 in microvessels from Ang II infused mice depends on products of both COX-1 and -2 that activate TP-Rs. Thus, combined blockade of COX-1 and -2 or TP-Rs may prevent vascular ROS and its many complications during increased Ang II and ET-1, such as hypertension, hypoxia or shock.

scholarly journals Cyclooxygenases Inhibitors Efficiently Induce Cardiomyogenesis in Human Pluripotent Stem Cells

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 554 ◽  
Author(s):  
Harshal Nemade ◽  
Aviseka Acharya ◽  
Umesh Chaudhari ◽  
Erastus Nembo ◽  
Filomain Nguemo ◽  
...  
Keyword(s):  
Wnt Signaling Pathway ◽  
Calcium Transient ◽  
Cardiac Differentiation ◽  
Cyclooxygenase Inhibitors ◽  
Cox Inhibitors ◽  
Screening Model ◽  
Cox 2 ◽  
Transient Measurements ◽  
Cox 1

Application of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is limited by the challenges in their efficient differentiation. Recently, the Wingless (Wnt) signaling pathway has emerged as the key regulator of cardiomyogenesis. In this study, we evaluated the effects of cyclooxygenase inhibitors on cardiac differentiation of hPSCs. Cardiac differentiation was performed by adherent monolayer based method using 4 hPSC lines (HES3, H9, IMR90, and ES4SKIN). The efficiency of cardiac differentiation was evaluated by flow cytometry and RT-qPCR. Generated hPSC-CMs were characterised using immunocytochemistry, electrophysiology, electron microscopy, and calcium transient measurements. Our data show that the COX inhibitors Sulindac and Diclofenac in combination with CHIR99021 (GSK-3 inhibitor) efficiently induce cardiac differentiation of hPSCs. In addition, inhibition of COX using siRNAs targeted towards COX-1 and/or COX-2 showed that inhibition of COX-2 alone or COX-1 and COX-2 in combination induce cardiomyogenesis in hPSCs within 12 days. Using IMR90-Wnt reporter line, we showed that inhibition of COX-2 led to downregulation of Wnt signalling activity in hPSCs. In conclusion, this study demonstrates that COX inhibition efficiently induced cardiogenesis via modulation of COX and Wnt pathway and the generated cardiomyocytes express cardiac-specific structural markers as well as exhibit typical calcium transients and action potentials. These cardiomyocytes also responded to cardiotoxicants and can be relevant as an in vitro cardiotoxicity screening model.

scholarly journals Intraluteal regulation of prostaglandin F2α-induced prostaglandin biosynthesis in pseudopregnant rabbits

Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 1005-1016 ◽  
Author(s):  
M Zerani ◽  
C Dall’Aglio ◽  
M Maranesi ◽  
A Gobbetti ◽  
G Brecchia ◽  
...  
Keyword(s):  
Prostaglandin F2α ◽  
Enzymatic Activities ◽  
Synthesis Rate ◽  
Corpora Lutea ◽  
Positive Staining ◽  
Mrna Levels ◽  
Cox 2 ◽  
Pg E2 ◽  
Cox 1

The objective of the present study was to investigate in rabbit corpora lutea (CL), at both the cellular and molecular level, intraluteal cyclooxygenase (COX)-1, COX-2 and prostaglandin (PG) E2-9-ketoreductase (PGE2-9-K) enzymatic activities as well asin vitroPGE2 and PGF2α synthesis following PGF2α treatment at either early- (day-4) or mid-luteal (day-9) stage of pseudopregnancy. By immunohistochemistry, positive staining for COX-2 was localized in luteal and endothelial cells of stromal arteries at both the stages. In CL of both stages, basal COX-2 mRNA levels were poorly expressed, but rose (P< 0.01) 4- to 10-fold 1.5–6 h after treatment and then gradually decreased within 24 h. Compared to mid-stage, day-4 CL had lower (P< 0.01) COX-2 and PGE2-9-K basal activities, and PGF2α synthesis rate, but higher (P< 0.01) PGE2 production. Independent of luteal stage, PGF2α treatment did not affect COX-1 activity. In day-4 CL, PGF2α induced an increase (P< 0.01) in both COX-2 activity and PGF2α synthesis, whereas that of PGE2 remained unchanged. In day-9 CL, PGF2α up-regulated (P< 0.01) both COX-2 and PGE-9-K activities, and PGF2α production, but decreased (P< 0.01) PGE2 synthesis. All changes in gene expression and enzymatic activities occurred within 1.5 h after PGF2α challenge and were more marked in day-9 CL. Our data suggest that PGF2α directs intraluteal PG biosynthesis in mature CL, by affecting the CL biosynthetic machinery to increase the PGF2α synthesis in an auto-amplifying manner, with the activation of COX-2 and PGE-9-K; this may partly explain their differentially, age-dependent, luteolytic capacity to exogenous PGF2α in rabbits.

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