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1

Clinical pharmacology of selective COX-2 inhibitors.  

PubMed

The discovery of cyclooxygenase (COX)-2 has provided the rationale for the development of a new class of nonsteroidal antiinflammatory drugs (NSAIDs), the selective COX-2 inhibitors (denominated coxibs), with the aim of reducing the gastrointestinal (GI) toxicity associated with the administration of NSAIDs by virtue of COX-1 sparing. Rofecoxib and celecoxib are the first selective COX-2 inhibitors approved by the FDA and EMEA for the treatment of rheumatoid arthritis (RA), osteoarthritis (OA) and for relief of acute pain. Rofecoxib has been shown to spare COX-1 activity ex vivo, in platelets and gastric mucosa, when administered at therapeutic doses or above. In a large clinical trial, COX-2 inhibitors have been demonstrated to halve the incidence of serious upper GI events vs a nonselective NSAID. Recently, other selective COX-2 inhibitors with different COX-1/COX-2 selectivity and pharmacokinetic features have been developed, i.e. valdecoxib, parecoxib, etoricoxib and lumiracoxib. The improved biochemical selectivity of valdecoxib vs celecoxib in vitro (COX-1/COX-2 ratio: 60 vs 30, respectively) may be clinically relevant leading to an improved GI safety. Interestingly, parecoxib, a pro-drug of valdecoxib, is the only injectable coxib. Etoricoxib, showing only a slightly higher COX-2 selectivity than rofecoxib in vitro (COX-1/COX-2 ratio: 344 vs 272, respectively), has been reported to cause a similar specific COX-2 inhibition ex vivo that should translate into comparable GI safety. Lumiracoxib, the most selective COX-2 inhibitor in vitro (COX-1/COX-2 ratio: 400), is the only acidic coxib. It has been hypothesized that this pecular chemical feature may lead to an enhanced concentration in inflammatory sites that may translate into an improved clinical efficacy. The results of clinical trials have shown that coxibs have a comparable clinical efficacy and renal toxicity and an improved GI safety vs nonselective NSAIDs. Whether the different pharmacodynamic and pharmacokinetics features of the various coxibs will produce detectable differences in efficacy and toxicity remains to be evaluated in appropriate comparative randomized clinical studies. PMID:14552704

Capone, M L; Tacconelli, S; Sciulli, M G; Patrignani, P

2003-01-01

2

NSAIDs: gastroprotection or selective COX-2 inhibitor?  

PubMed

Conventional nonsteroidal anti-inflammatory drugs (NSAIDs) are effective adjuvant analgesics commonly encountered in palliative care. However, these drugs are associated with adverse effects that are primarily due to gastrointestinal toxicity, with resultant serious complications such as gastroduodenal perforations, ulcers and bleeds. This toxicity has been attributed to inhibition of cyclooxygenase-1 (COX-1). Factors known to increase this risk of toxicity include age above 65 years, classification of NSAID in terms of COX-1/COX-2 selectivity, previous history of complications and coadministration of aspirin, anticoagulants and corticosteroids. Selective inhibitors of cyclooxygenase-2 (COX-2) were developed in an attempt to reduce this association; trials to date confirm that these drugs do indeed have reduced incidence of gastroduodenal toxicity. Prior to the introduction of the COX-2 selective inhibitors, patients at high risk were often coprescribed a gastroprotective agent (such as misoprostol or a proton pump inhibitor) with a conventional NSAID. This review discusses the merits of both options and devises a treatment strategy for the safe and cost-effective use of these drugs in the palliative care population. PMID:15198117

Dickman, Andrew; Ellershaw, John

2004-05-01

3

Is COX-2 a perpetrator or a protector? Selective COX-2 inhibitors remain controversial.  

PubMed

COX-2(cyclooxygenase-2) has sparked a surge in pharmaceutical interest since its discovery at the beginning of the 1990s. Several COX-2 selective inhibitors that avoid gastrointestinal side effects have been successfully launched into the market in recent years. The first selective COX-2 inhibitor, celecoxib, entered the market in December 1998 [corrected] However, there are a few organs that physiologically and functionally express COX-2, particularly the glomeruli of the kidney and the cortex of the brain. Inhibition of COX-2 expression in these organs possibly causes heart attack and stroke in long-term COX-2 inhibitor users. Recently, a USA Food and Drug Agency (FDA) advisory panel re-evaluated COX-2 inhibitors and unanimously concluded that the entire class of COX-2 inhibitors increase the risk of cardiovascular problems. Thus the use of COX-2 inhibitors is still controversial, and there is a challenge for not only pharmacologists, but also the pharmaceutical industry, to develop improved painkilling and anti-inflammatory drugs. This may involve exploring a new generation of COX-2 inhibitors with different inhibitory mechanisms through computer-aided design, screening different sources of inhibitors with lower selectivity, or seeking completely new targets. Synthetic COX-2 inhibitors have high selectivity and the advantage of irreversible inhibition, whereas naturally derived COX-2 inhibitors have lower selectivity and fewer side effects, with the medical effects in general not being as striking as those achieved using synthetic inhibitors. This review discusses the mechanism of COX-2 inhibitor therapy and a possible new way of exploration in the development of anti-inflammatory, analgetic, and antipyretic drugs. PMID:16038624

Luo, Cheng; He, Ming-liang; Bohlin, Lars

2005-08-01

4

Clinical pharmacology of novel selective COX-2 inhibitors.  

PubMed

Novel coxibs (i.e. etoricoxib, valdecoxib, parecoxib and lumiracoxib) with enhanced biochemical cyclooxygenase (COX)-2 selectivity over that of rofecoxib and celecoxib have been recently developed. They have the potential advantage to spare COX-1 activity, thus reducing gastrointestinal toxicity, even when administered at high doses to improve efficacy. They are characterized by different pharmacodynamic and pharmacokinetics features. The higher biochemical selectivity of valdecoxib than celecoxib, evidenced in vitro, may be clinically relevant leading to an improved gastrointestinal safety. Interestingly, parecoxib, a pro-drug of valdecoxib, is the only injectable coxib. Etoricoxib shows only a slightly improved COX-2 selectivity than rofecoxib, a highly selective COX-2 inhibitor that has been reported to halve the incidence of serious gastrointestinal toxicity compared to nonselective nonsteroidal antiinflammatory drugs (NSAIDs). Lumiracoxib, the most selective COX-2 inhibitor in vitro, is the only acidic coxib. The hypothesis that this chemical property may lead to an increased and persistent drug accumulation in inflammatory sites and consequently to an improved clinical efficacy, however, remains to be verified. Several randomized clinical studies suggest that the novel coxibs have comparable efficacy to nonselective NSAIDs in the treatment of osteoarthritis, rheumatoid arthritis and acute pain, but they share similar renal side-effects. The apparent dose-dependence of renal toxicity may limit the use of higher doses of the novel coxibs for improved efficacy. Large-size randomized clinical trials are ongoing to define the gastrointestinal and cardiovascular safety of the novel coxibs. PMID:14965322

Tacconelli, S; Capone, M L; Patrignani, P

2004-01-01

5

Clinical use and pharmacological properties of selective COX-2 inhibitors.  

PubMed

Selective COX-2 inhibitors (coxibs) are approved for the relief of acute pain and symptoms of chronic inflammatory conditions such as osteoarthritis (OA) and rheumatoid arthritis (RA). They have similar pharmacological properties but a slightly improved gastrointestinal (GI) safety profile if compared to traditional nonsteroidal anti-inflammatory drugs (tNSAIDs). However, long-term use of coxibs can be associated with an increased risk for cardiovascular (CV) adverse events (AEs). For this reason, two coxibs were withdrawn from the market. Currently celecoxib, etoricoxib, and lumiracoxib are used. These three coxibs differ in their chemical structure and selectivity for COX-2, which might explain some of their pharmacological features. Following oral administration, the less lipophilic celecoxib has a lower bioavailability (20-40%) than the other two coxibs (74-100%). All are eliminated by hepatic metabolism involving mainly CYP2C9 (celecoxib, lumiracoxib) and CYP3A4 (etoricoxib). Elimination half-life varies from 5 to 8 h (lumiracoxib), 11 to 16 h (celecoxib) and 19 to 32 h (etoricoxib). In patients with liver disease, plasma levels of celecoxib and etoricoxib are increased about two-fold. Clinical efficacies of the coxibs are comparable to tNSAIDs. There is an ongoing discussion about whether the slightly better GI tolerability (which is lost if acetylsalicylic acid is coadministered) of the coxibs is offset by their elevated risks for CV AEs (also seen with tNSAIDs other than naproxen), which apparently increase with dose and duration of exposure. In addition, the higher costs for coxibs (if compared to tNSAIDs, even when a "gastroprotective" proton pump inhibitor is coadministered) should be taken into consideration, if a coxib will be selected for certain patients with a high risk for GI complications. For such treatment, the lowest effective dose should be used for a limited time. Monitoring of kidney function and blood pressure appears advisable. It is hoped that further controlled studies can better define the therapeutic place of the coxibs. PMID:17999057

Shi, Shaojun; Klotz, Ulrich

2008-03-01

6

Design and synthesis of 1,3-diarylurea derivatives as selective cyclooxygenase (COX-2) inhibitors.  

PubMed

A group of 1,3-diarylurea derivatives, possessing a methylsulfonyl pharmacophore at the para-position of the N-1 phenyl ring, in conjunction with a N-3 substituted-phenyl ring (4-F, 4-Cl, 4-Me, 4-OMe), were designed and synthesized for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 1-(4-methylsulfonylphenyl)-3-(4-methoxyphenyl) urea (4e) as a potent COX-2 inhibitor (IC(50)=0.11 microM) with a high COX-2 selectivity index (SI=203.6) comparable to the reference drug celecoxib (COX-2 IC(50)=0.06 microM; COX-2 SI=405). The structure-activity data acquired indicate that the urea moiety constitutes a suitable scaffold to design new acyclic 1,3-diarylurea derivatives with selective COX-2 inhibitory activity. PMID:18226898

Zarghi, Afshin; Kakhgi, Samaneh; Hadipoor, Atefeh; Daraee, Bahram; Dadrass, Orkideh G; Hedayati, Mehdi

2008-02-15

7

Selective COX-2 Inhibitors: A Review of Their Structure-Activity Relationships  

PubMed Central

Non-steroidal anti-inflammatory drugs (NSAIDs) are the competitive inhibitors of cyclooxygenase (COX), the enzyme which mediates the bioconversion of arachidonic acid to inflammatory prostaglandins (PGs). Their use is associated with the side effects such as gastrointestinal and renal toxicity. The therapeutic anti-inflammatory action of NSAIDs is produced by the inhibition of COX-2, while the undesired side effects arise from inhibition of COX-1 activity. Thus, it was though that more selective COX-2 inhibitors would have reduced side effects. Based upon a number of selective COX-2 inhibitors (rofecoxib, celecoxib, valdecoxibetc.) were developed as safer NSAIDs with improved gastric safety profile. However, the recent market removal of some COXIBs such as rofecoxib due to its adverse cardiovascular side effects clearly encourages the researchers to explore and evaluate alternative templates with COX-2 inhibitory activity. Recognition of new avenues for selective COX-2 inhibitors in cancer chemotherapy and neurological diseases such as Parkinson and Alzheimer’s diseases still continues to attract investigations on the development of COX-2 inhibitors. This review highlights the various structural classes of selective COX-2 inhibitors with special emphasis on their structure-activity relationships. PMID:24250402

Zarghi, Afshin; Arfaei, Sara

2011-01-01

8

Synthesis, biological evaluation, and docking studies of novel heterocyclic diaryl compounds as selective COX-2 inhibitors.  

PubMed

Three novel series of diaryl heterocyclic derivatives bearing the 2-oxo-5H-furan, 2-oxo-3H-1,3-oxazole, and 1H-pyrazole moieties as the central heterocyclic ring were synthesized and their in vitro inhibitory activities on COX-1 and COX-2 isoforms were evaluated using a purified enzyme assay. The 2-oxo-5H-furan derivative 6b was identified as potent COX inhibitor with selectivity toward COX-1 (COX-1 IC(50)=0.061 microM and COX-2 IC(50)=0.325 microM; selectivity index (SI)=0.19). Among the 1H-pyrazole derivatives, 11b was found to be a potent COX-2 inhibitor, about 38 times more potent than Rofecoxib (COX-2 IC(50)=0.011 microM and 0.398 microM, respectively), but showed no selectivity for COX-2 isoform. Compound 11c demonstrated strong and selective COX-2 inhibitory activity (COX-1 IC(50)=1 microM, COX-2 IC(50)=0.011 microM; SI= approximately 92). Molecular docking studies of compounds 6b and 11b-d into the binding sites of COX-1 and COX-2 allowed to shed light on the binding mode of these novel COX inhibitors. PMID:20692174

Eren, Gökçen; Unlü, Serdar; Nuñez, Maria-Teresa; Labeaga, Luis; Ledo, Francisco; Entrena, Antonio; Bano?lu, Erden; Costantino, Gabriele; Sahin, M Fethi

2010-09-01

9

Select Dietary Phytochemicals Function as Inhibitors of COX-1 but Not COX-2  

PubMed Central

Recent clinical trials raised concerns regarding the cardiovascular toxicity of selective cyclooxygenase-2 (COX-2) inhibitors. Many active dietary factors are reported to suppress carcinogenesis by targeting COX-2. A major question was accordingly raised: why has the lifelong use of phytochemicals that likely inhibit COX-2 presumably not been associated with adverse cardiovascular side effects. To answer this question, we selected a library of dietary-derived phytochemicals and evaluated their potential cardiovascular toxicity in human umbilical vein endothelial cells. Our data indicated that the possibility of cardiovascular toxicity of these dietary phytochemicals was low. Further mechanistic studies revealed that the actions of these phytochemicals were similar to aspirin in that they mainly inhibited COX-1 rather than COX-2, especially at low doses. PMID:24098505

Li, Haitao; Zhu, Feng; Sun, Yanwen; Li, Bing; Oi, Naomi; Chen, Hanyong; Lubet, Ronald A.; Bode, Ann M.; Dong, Zigang

2013-01-01

10

The 2'-Trifluoromethyl Analogue of Indomethacin Is a Potent and Selective COX-2 Inhibitor.  

PubMed

Indomethacin is a potent, time-dependent, nonselective inhibitor of the cyclooxygenase enzymes (COX-1 and COX-2). Deletion of the 2'-methyl group of indomethacin produces a weak, reversible COX inhibitor, leading us to explore functionality at that position. Here, we report that substitution of the 2'-methyl group of indomethacin with trifluoromethyl produces CF3-indomethacin, a tight-binding inhibitor with kinetic properties similar to those of indomethacin and unexpected COX-2 selectivity (IC50 mCOX-2 = 267 nM; IC50 oCOX-1 > 100 ?M). Studies with site-directed mutants reveal that COX-2 selectivity results from insertion of the CF3 group into a small hydrophobic pocket formed by Ala-527, Val-349, Ser-530, and Leu-531 and projection of the methoxy group toward a side pocket bordered by Val-523. CF3-indomethacin inhibited COX-2 activity in human head and neck squamous cell carcinoma cells and exhibited in vivo anti-inflammatory activity in the carrageenan-induced rat paw edema model with similar potency to that of indomethacin. PMID:23687559

Blobaum, Anna L; Uddin, Md Jashim; Felts, Andrew S; Crews, Brenda C; Rouzer, Carol A; Marnett, Lawrence J

2013-05-01

11

COX-2 selective inhibitors cardiac toxicity: getting to the heart of the matter.  

PubMed

On September 30, 2004, Merck and Co. voluntary withdrew rofecoxib (Vioxx) from the market due to increased risk of cardiovascular events associated with the drug. This raised some issues. It is unclear whether the cardiac toxicities associated with rofecoxib isare due to its high COX-2 selectivity. Rofecoxib is the most specific COX-2 inhibitor among the first generation of the class, i.e., negligible COX-1 inhibitory effect. In addition to the gastrointestinal side effects, COX-1 inhibition is known to offer cardioprotection. This is one of the main present indications of aspirin-like drugs. It is plausible that the COX-2 inhibition is associated with altered homeostasis that is compensated with the cardioprotection effect of COX-1 inhibition that patients receive either through the less COX-2 selectivity of other NSAIDs or through co-administration of low dose aspirin. In addition, the cardiac toxicity of rofecoxib could be due to its unique chemical structure, its pharmacokinetics and tissue distribution, and/or the presence of toxic metabolites. Nevertheless, one cannot ignore the public need for NSAIDs with less gastrointestinal side effects than the traditional drugs. However, based on some available indirect evidence, and unless more clear-cut data become available, the use of highly COX-2 selective NSAIDs without the use of a suitable COX-1 inhibitor, (e.g., low dose aspirin) may be best avoided. This may be particularly relevant to the chronic use of these drugs. PMID:15576013

Davies, Neal M; Jamali, Fakhreddin

2004-10-29

12

COX-2 Inhibitors and Gastric Cancer  

PubMed Central

The evidence that cyclooxygenase-2 (COX-2) is upregulated and plays an important role in carcinogenesis of gastric cancer has triggered the topic of COX-2 inhibitors as chemopreventive agents for gastric cancer. Studies find that COX-2 inhibitors are associated not only with chemoprophylactic effects, but also with chemotherapeutic potentials in gastric cancer. Both COX-dependent and COX-independent pathways have a role in the anticancer efficiency of COX-2 inhibitors. However, enthusiasm is thwarted by the potential toxicity, that is, gastrointestinal toxicity of nonselective COX-2 inhibitors and cardiovascular risk of selective COX-2 inhibitors. Therefore, more studies are needed to develop new targeted antitumor agents (such as prostaglandin E receptor antagonist) and to define fundamental questions such as optimal treatment regimens, integration of cotherapy, and careful selection of candidates. PMID:25371669

Wang, Zhen; Chen, Jun-qiang; Liu, Jin-lu

2014-01-01

13

Synthesis and biological evaluation of 3-heteroaryloxy-4-phenyl-2(5H)-furanones as selective COX-2 inhibitors.  

PubMed

A series of 3-heteroaryloxy4-phenyl-2-5H)-furanones were prepared and evaluated for their potency and selectivity as COX-2 inhibitors. This led to the identification of L-778,736 as a potent, orally active and selective inhibitor of the COX-2 enzyme. PMID:10576685

Lau, C K; Brideau, C; Chan, C C; Charleson, S; Cromlish, W A; Ethier, D; Gauthier, J Y; Gordon, R; Guay, J; Kargman, S; Li, C S; Prasit, P; Riendeau, D; Thérien, M; Visco, D M; Xu, L

1999-11-15

14

Sulfonilamidothiopyrimidone and thiopyrimidone derivatives as selective COX-2 inhibitors: synthesis, biological evaluation, and docking studies.  

PubMed

Newly synthesized sulfonilamidothiopyrimidone derivatives and a subset of 14 sulfonilamidothiopyrimidones and thiopyrimidones selected by an MTT assays cell viability guided selection from an in house collection were evaluated to determine the inhibitory effect on the PGE(2) formation in human peripheral blood lymphocytes (PBLs) using commercial ELISA. The newly synthesized sulfonilamidothiopyrimidone derivatives showed interesting pharmacological activities. Preliminary in vitro assays showed that compounds 2-5 are endowed with very high activity. Compound 2 was the most active as hCOX-2 inhibitor. The observed effects were not due to an inhibition of cell proliferation as proved by the BrdU assay. Western blot of COX-2 confirmed the inhibition on the PGE(2) secretion. Further evidence on the inhibitory potential and selectivity as COX-2 inhibitors of the selected compounds came from the in vitro screening. In order to better rationalize the action and the binding mode of these compounds, docking studies were carried out. These studies were in agreement with the biological data. Compounds 2-5 were able to fit into the active site of COX-2 with highest scores and interaction energies. Furthermore, compound 2, which showed an inhibition of around 50% on PGE(2) production, was the best scored in all the docking calculations carried out. PMID:23047231

Basile, Livia; Alvarez, Susana; Blanco, Almudena; Santagati, Andrea; Granata, Giuseppe; Di Pietro, Patrizia; Guccione, Salvatore; Muñoz-Fernández, M Ángeles

2012-11-01

15

Design and synthesis of new 1,3-benzthiazinan-4-one derivatives as selective cyclooxygenase (COX-2) inhibitors.  

PubMed

A new group of 1, 3-benthiazinan-4-ones, possessing a methyl sulfonyl pharmacophore, were synthesized and their biological activities were evaluated for cyclooxygenase-2 (COX-2) inhibitory activity. In vitro COX-1/COX-2 inhibition studies identified 3-(p-fluoropheny)-2-(4-methylsulfonylphenyl)-1,3-benzthiazinan-4-one (7b) as a potent (IC(50)=0.05 microM) and selective (selectivity index=259) COX-2 inhibitor. PMID:19596198

Zarghi, Afshin; Zebardast, Tannaz; Daraie, Bahram; Hedayati, Mehdi

2009-08-01

16

N-1 and C-3 substituted indole Schiff bases as selective COX-2 inhibitors: synthesis and biological evaluation.  

PubMed

A group of N-1 and C-3 disubstituted-indole Schiff bases bearing an indole N-1 (R'=H, CH(2)Ph, COPh) substituent in conjunction with a C-3 -C=HN-C(6)H(4)-4-X (X=F, Me, CF(3), Cl) substituent were synthesized and evaluated as inhibitors of cyclooxygenase (COX) isozymes (COX-1/COX-2). Within this group of Schiff bases, compounds 15 (R(1)=CH(2)Ph, X=F), 17 (R(1)=CH(2)Ph, X=CF(3)), 18 (R(1)=COPh, X=F) and 20 (R(1)=COPh, X=CF(3)) were identified as effective and selective COX-2 inhibitors (COX-2 IC(50)'s=0.32-0.84 ?M range; COX-2 selectivity index (SI)=113 to >312 range). 1-Benzoyl-3-[(4-trifluoromethylphenylimino)methyl]indole (20) emerged as the most potent (COX-1 IC(50) >100 ?M; COX-2 IC(50)=0.32 ?M) and selective (SI >312) COX-2 inhibitor. Furthermore, compound 20 is a selective COX-2 inhibitor in contrast to the reference drug indomethacin that is a potent and selective COX-1 inhibitor (COX-1 IC(50)=0.13 ?M; COX-2 IC(50)=6.9 ?M, COX-2 SI=0.02). Molecular modeling studies employing compound 20 showed that the phenyl CF(3) substituent attached to the CN spacer is positioned near the secondary pocket of the COX-2 active site, the CN nitrogen atom is hydrogen bonded (N···NH=2.85 Å) to the H90 residue, and the indole N-1 benzoyl is positioned in a hydrophobic pocket of the COX-2 active site near W387. PMID:22361134

Kaur, Jatinder; Bhardwaj, Atul; Huang, Zhangjian; Knaus, Edward E

2012-03-15

17

Design and synthesis of benzimidazole analogs endowed with oxadiazole as selective COX-2 inhibitor.  

PubMed

New molecules of benzimidazole endowed with oxadiazole were designed and synthesized from 2-(2-((pyrimidin-2-ylthio)methyl)-1H-benzo[d]imidazol-1-yl)acetohydrazide as 1-((5-substituted alkyl/aryl-1,3,4-oxadiazol-2-yl)methyl)-2-((pyrimidin-2-ylthio)methyl)-1H-benzimidazoles (5a-r) with the aim to acquire selective cyclooxygenase (COX-2) inhibitor activity. The synthesized compounds were screened by in vitro cyclooxygenase assays to determine COX-1 and COX-2 inhibitory potency and the results showed that they had good-to-remarkable activity with an IC50 range of 11.6-56.1?µM. The most active compounds were further screened for their in vivo anti-inflammatory activity by using the carrageenan-induced rat paw edema model. In vitro anticancer activities of the hybrid compounds were assessed by the National Cancer Institute (NCI), USA, against 60 human cell lines, and the results showed a good spectrum. Compound 5l exhibited significant COX-2 inhibition with an IC50 value of 8.2?µM and a percent protection of 68.4%. Compound 5b evinced moderate cytotoxicity toward the UO-31 cell line of renal cancer. A docking study was performed using Maestro 9.0, to provide the binding mode into the binding sites of the cyclooxygenase enzyme. Hopefully, in the future, compound 5l could serve as a lead compound for developing new COX-2 inhibitors. PMID:25303727

Rathore, Ankita; Rahman, Mujeeb Ur; Siddiqui, Anees Ahamad; Ali, Abuzer; Shaharyar, Mohammad

2014-12-01

18

Synthesis of novel pyrazole–thiadiazole hybrid as potential potent and selective cyclooxygenase-2 (COX-2) inhibitors.  

PubMed

A series of 1,3,4-trisubstituted pyrazole derivatives (3 a-f), (4 a-f), and (5 a-f) have been synthesized and evaluated for their cyclooxygenase (COX-1 and COX-2) inhibitory activity. The structures of newly synthesized compounds were characterized by IR, 1H NMR, and mass spectral analysis. All of the compounds showed good inhibition of COX-2 with IC50 of 1.33-17.5 ?M. Among these derivatives, compound (5c) was the most potent and selective COX-2 inhibitor (IC50 = 1.33 ?M), with a significant selectivity index (SI > 60). Molecular docking studies were carried out in order to predict the hypothetical binding mode of these compounds to the COX-2 isoenzyme. The result of present study suggests that pyrazole-thiadiazole hybrid could be an interesting approach for the design of new selective COX-2 inhibitory agents. PMID:25444084

Alegaon, S G; Hirpara, M B; Alagawadi, K R; Hullatti, K K; Kashniyal, K

2014-11-15

19

Design and synthesis of new 1,3-benzdiazinan-4-one derivatives as selective cyclooxygenase (COX-2) inhibitors.  

PubMed

A new group of regioisomeric 2,3-diaryl-1,3-benzdiazinan-4-ones, possessing a methyl sulfonyl pharmacophore, were synthesized and their biological activities were tested for cyclooxygenase-2 (COX-2) inhibitory activity. In vitro COX-1/COX-2 inhibition studies identified 3-(p-fluorophenyl)-2-(4-methylsulfonylphenyl)-1,3-benzdiazinane-4-one (2b) as a potent and highly selective (IC(50) = 0.07 µM; selectivity index = 572.8) COX-2 inhibitor. PMID:22076641

Zarghi, Afshin; Zebardast, Tannaz; Hajighasemali, Fatemeh; Alipoor, Eskandar; Daraie, Bahram; Hedayati, Mehdi

2012-04-01

20

Helicobacter pylori attenuates the delay in ulcer healing induced by aspirin and selective COX2 inhibitor  

Microsoft Academic Search

Helicobacter pylori (H. pylori) and NSAIDs are recognized as major pathogenic factors in peptic ulcer disease. However, whether these two factors exert synergistic or antagonistic effects on ulcer healing has not yet been fully explained. In this study, the effects of aspirin (ASA) alone and rofecoxib, a specific prostaglandin cyclooxygenase (COX)-2 inhibitor, were compared with that of ASA and rofecoxib

Tomasz Brzozowski; Peter C. Konturek; Zbigniew Sliwowski; Stanislaw Konturek; Wladyslaw Bielanski; Robert Pajdo; Danuta Drozdowicz; Eckhart Hahn

2002-01-01

21

Design, synthesis, and biological evaluation of substituted hydrazone and pyrazole derivatives as selective COX-2 inhibitors: Molecular docking study.  

PubMed

New arylhydrazone derivatives and a series of 1,5-diphenyl pyrazoles were designed and synthesized from 1-(4-chlorophenyl)-4,4,4-trifuorobutane-1,3-dione 1. The newly synthesized compounds were investigated in vivo for their anti-inflammatory activities using carrageenan-induced rat paw oedema model. Moreover, they were tested for their inhibitory activity against ovine COX-1 and COX-2 using an in vitro cyclooxygenase (COX) inhibition assay. Some of the new compounds (2f, 6a and 6d) showed a reasonable in vitro COX-2 inhibitory activity, with IC?? value of 0.45 ?M and selectivity index of 111.1. A virtual screening was carried out through docking the designed compounds into the COX-2 binding site to predict if these compounds have analogous binding mode to the COX-2 inhibitors. Docking study of the synthesized compounds 2f, 6a and 6d into the active site of COX-2 revealed a similar binding mode to SC-558, a selective COX-2 inhibitor. PMID:21570309

El-Sayed, Magda A-A; Abdel-Aziz, Naglaa I; Abdel-Aziz, Alaa A-M; El-Azab, Adel S; Asiri, Yousif A; Eltahir, Kamal E H

2011-06-01

22

Discovery of a potent and selective COX-2 inhibitor in the alkoxy lactone series with optimized metabolic profile.  

PubMed

The COX-2 inhibitor DFP [5,5-dimethyl-3-(2-propoxy)-4-methanesulfonylphenyl)-2(5H)-furanone] was found to have a long half-life in humans. Analogues have been characterized in order to optimize pharmacokinetics. This has lead to the discovery of 5(S)-(5-ethyl-5-methyl-3-(2-propoxy)-4-methanesulfonylphenyl)-2(5H)-furanone analogue 11 a potent and selective COX-2 inhibitor which is metabolized to a greater extent than DFP upon incubation with rat and human hepatocytes, suggesting a shorter half-life in humans. PMID:12392741

Leblanc, Yves; Roy, Patrick; Wang, Zhaoyin; Li, Chun Sing; Chauret, Nathalie; Nicoll-Griffith, Deborah A; Silva, José M; Aubin, Yves; Yergey, James A; Chan, Chi Chung; Riendeau, Denis; Brideau, Christine; Gordon, Robert; Xu, Lijing; Webb, Janine; Visco, Denise M; Prasit, Petpiboon

2002-11-18

23

COX-2-selective inhibitor, etodolac, suppresses choroidal neovascularization in a mice model.  

PubMed

Cyclooxygenases (COXs) are involved in choroidal neovascularization (CNV). However, the relative contribution of COX-1 and -2 to CNV has not been determined. In this study, the expression of COX-2 was investigated in CNVs in a murine laser-induced model. Subsequently, we found that experimental CNV expressed COX-2, most remarkably around the highly vascularized lesions. To examine the effect of COX-2 inhibition on CNV, etodolac, a non-steroidal anti-inflammatory drug with a high COX-2 selectivity, was tested on murine CNV model. The results demonstrated that the intensity of fluorescein leakage from the photocoagulated lesions decreased significantly compared to the control eyes following etodolac administration. The area of CNV lesions, as examined using histological sections and choroidal flatmounts at day 7, demonstrated that the average size of the CNV lesions was significantly reduced in the etodolac-treated eyes compared to the control eyes. Together, our results demonstrated that selective COX-2 inhibition suppresses CNV. PMID:15530415

Takahashi, Hidenori; Yanagi, Yasuo; Tamaki, Yasuhiro; Uchida, Saiko; Muranaka, Kimimasa

2004-12-10

24

The Gastrointestinal Safety and Effect on Disease Activity of Etoricoxib, a Selective Cox2 Inhibitor in Inflammatory Bowel Diseases  

Microsoft Academic Search

BACKGROUND:While traditional nonsteroidal antiinflammatory drugs (t-NSAIDs) are relatively contraindicated in patients with inflammatory bowel disease (IBD) for fear of disease aggravation, controlled clinical trials showed that cyclo-oxygenase-2 inhibitors have fewer gastrointestinal side effects than the t-NSAIDs. Etoricoxib is a new antiinflammatory inhibitor that has high Cox-2 selectivity.OBJECTIVES:To assess the safety of etoricoxib and effect on disease activity in patients with

Yasser El Miedany; Sally Youssef; Ihab Ahmed; Maha El Gaafary

2006-01-01

25

COX-2 inhibitors and cardiovascular risk.  

PubMed

The development of drugs that selectively inhibit cyclooxygenase-2 (COX-2) demonstrates translational research from bench to bedside based on underlying knowledge of micro-cellular structure and function. However, theoretical concerns about potentially prothrombotic effects of selective COX-2 inhibitors coupled with observations of increased cardiovascular risk have produced significant consternation and lead to the withdrawal of two of these agents from the market. A number of questions remain unanswered. It appears clear that both selective and non-selective COX inhibitors are associated with increases in blood pressure. In addition, blood pressure is often increased after starting nonsteroidal therapy, and we know that even small increases in blood pressure in subjects with pre-existing vascular disease are associated with substantial increases in the risk of cardiovascular morbidity. Given this line of reasoning, one might hypothesize that the observed increases in the risk of cardiovascular events associated with COX-inhibitors are largely due to increases in blood pressure in populations of subjects who are already at high risk. But can we generalize that the adverse cardiovascular effects observed for rofecoxib and valdecoxib are sufficient to indict the entire class of COX-2 inhibitors, or is this not a class effect, but dependent upon the degree of COX-2 selectivity? In either case, it seems prudent to recommend that subjects who are at higher risk for a cardiovascular event and receiving a COX-inhibitor should also be treated with low dose ASA with close follow up of blood pressure and efficacious use of anti-hypertensive medications. Finally, modest dietary salt restriction may help lessen the effects of COX-inhibitors on blood pressure. PMID:17612050

Salzberg, Daniel J; Weir, Matthew R

2007-01-01

26

Binding Energy Calculation of Patchouli Alcohol Isomer Cyclooxygenase Complexes Suggested as COX-1/COX-2 Selective Inhibitor.  

PubMed

To understand the structural features that dictate the selectivity of the two isoforms of the prostaglandin H2 synthase (PGHS/COX), the three-dimensional (3D) structure of COX-1/COX-2 was assessed by means of binding energy calculation of virtual molecular dynamic with using ligand alpha-Patchouli alcohol isomers. Molecular interaction studies with COX-1 and COX-2 were done using the molecular docking tools by Hex 8.0. Interactions were further visualized by using Discovery Studio Client 3.5 software tool. The binding energy of molecular interaction was calculated by AMBER12 and Virtual Molecular Dynamic 1.9.1 software. The analysis of the alpha-Patchouli alcohol isomer compounds showed that all alpha-Patchouli alcohol isomers were suggested as inhibitor of COX-1 and COX-2. Collectively, the scoring binding energy calculation (with PBSA Model Solvent) of alpha-Patchouli alcohol isomer compounds (CID442384, CID6432585, CID3080622, CID10955174, and CID56928117) was suggested as candidate for a selective COX-1 inhibitor and CID521903 as nonselective COX-1/COX-2. PMID:25484897

Raharjo, Sentot Joko; Mahdi, Chanif; Nurdiana, Nurdiana; Kikuchi, Takheshi; Fatchiyah, Fatchiyah

2014-01-01

27

Design and synthesis of 3-alkyl-2-aryl-1,3-thiazinan-4-one derivatives as selective cyclooxygenase (COX-2) inhibitors.  

PubMed

A new group of 3-alkyl-2-aryl-1,3-thiazinan-4-ones, possessing a methylsulfonyl pharmacophore, were synthesized and their biological activities were evaluated for cyclooxygenase-2 (COX-2) inhibitory activity. In vitro COX-1/COX-2 inhibition studies identified 3-benzyl-2-(4-methylsulfonylphenyl)-1,3-thiazinan-4-one (11a) as a potent (IC(50)=0.06 microM) and selective (selectivity index >285) COX-2 inhibitor. PMID:19447036

Zebardast, Tannaz; Zarghi, Afshin; Daraie, Bahram; Hedayati, Mehdi; Dadrass, Orkideh G

2009-06-15

28

Synthesis and Evaluation of Benzimidazole Derivatives as Selective COX-2 Inhibitors.  

PubMed

A new series of 1-{(5-substituted-alkyl/aryl-1,3,4-oxadiazol-2-yl)methyl}-2-(piperidin-1-ylmethyl)-1H-benzimidazoles (5a-5r) was synthesized and screened for their inhibitory activity against COX (1 and 2). In-vivo anti-inflammatory activity of potent compounds was done by carrageenan-induced rat paw edema model. In-vitro anticancer activity of synthesized compounds was also performed at the National Cancer Institute (NCI) against NCI 60 cell lines panel. Out of 18 compounds screened, 5h, 5i, 5j and 5l were found to be potent COX-2 inhibitors in the range of IC50 0.06-0.81 µM. In vivo anti-inflammatory screening results revealed that the compounds 5h and 5j manifested profound percent protection of 72.8 and 75.0%, respectively. Compound 5f exhibited moderate cytotoxicity with 58.79% growth inhibition against SNB-75 (CNS Cancer) cell lines and moderate activity against COX-2 (IC50 = 8.0 µM). PMID:25134430

Rathore, Ankita; Rahman, Mujeeb -Ur-; Siddiqui, Anees A; Ali, Abuzer; Yar, Mohammad Shahar

2014-08-15

29

Cost effectiveness of COX 2 selective inhibitors and traditional NSAIDs alone or in combination with a proton pump inhibitor for people with osteoarthritis  

PubMed Central

Objectives To investigate the cost effectiveness of cyclo-oxygenase-2 (COX 2) selective inhibitors and traditional non-steroidal anti-inflammatory drugs (NSAIDs), and the addition of proton pump inhibitors to these treatments, for people with osteoarthritis. Design An economic evaluation using a Markov model and data from a systematic review was conducted. Estimates of cardiovascular and gastrointestinal adverse events were based on data from three large randomised controlled trials, and observational data were used for sensitivity analyses. Efficacy benefits from treatment were estimated from a meta-analysis of trials reporting total Western Ontario and McMaster Universities (WOMAC) osteoarthritis index score. Other model inputs were obtained from the relevant literature. The model was run for a hypothetical population of people with osteoarthritis. Subgroup analyses were conducted for people at high risk of gastrointestinal or cardiovascular adverse events. Comparators Licensed COX 2 selective inhibitors (celecoxib and etoricoxib) and traditional NSAIDs (diclofenac, ibuprofen, and naproxen) for which suitable data were available were compared. Paracetamol was also included, as was the possibility of adding a proton pump inhibitor (omeprazole) to each treatment. Main outcome measures The main outcome measure was cost effectiveness, which was based on quality adjusted life years gained. Quality adjusted life year scores were calculated from pooled estimates of efficacy and major adverse events (that is, dyspepsia; symptomatic ulcer; complicated gastrointestinal perforation, ulcer, or bleed; myocardial infarction; stroke; and heart failure). Results Addition of a proton pump inhibitor to both COX 2 selective inhibitors and traditional NSAIDs was highly cost effective for all patient groups considered (incremental cost effectiveness ratio less than £1000 (€1175, $1650)). This finding was robust across a wide range of effectiveness estimates if the cheapest proton pump inhibitor was used. In our base case analysis, adding a proton pump inhibitor to a COX 2 selective inhibitor (used at the lowest licensed dose) was a cost effective option, even for patients at low risk of gastrointestinal adverse events (incremental cost effectiveness ratio approximately £10?000). Uncertainties around relative adverse event rates meant relative cost effectiveness for individual COX 2 selective inhibitors and traditional NSAIDs was difficult to determine. Conclusions Prescribing a proton pump inhibitor for people with osteoarthritis who are taking a traditional NSAID or COX 2 selective inhibitor is cost effective. The cost effectiveness analysis was sensitive to adverse event data and the specific choice of COX 2 selective inhibitor or NSAID agent should, therefore, take into account individual cardiovascular and gastrointestinal risks. PMID:19602530

2009-01-01

30

Selective Cox-2 inhibitor celecoxib induces epithelial-mesenchymal transition in human lung cancer cells via activating MEK-ERK signaling.  

PubMed

Increasing evidence has suggested that high expression level of cyclooxygenase-2 (Cox-2) is associated with the malignancies of non-small cell lung cancer (NSCLC), leading to a rationale of applying Cox-2 inhibitors as adjuvant therapy in the treatment of NSCLC. However, the addition of celecoxib, a selective Cox-2 inhibitor, to chemotherapy in clinical trials failed to benefit the survival of NSCLC patients, which urges the investigation to re-evaluate this strategy for NSCLC treatment. In this study, we observed that celecoxib treatment at clinically relevant concentrations induced epithelial-mesenchymal transition (EMT) in NSCLC cells regardless of Cox-2 status, which, however, was not recapitulated using another Cox-2 inhibitor, etodolac. Celecoxib-stimulated EMT in turn promoted cell invasion and rendered cells resistant to chemotherapy. Further mechanistic investigation by disrupting the integrity of signaling pathways using specific inhibitors or RNA interference revealed that celecoxib-induced EMT in NSCLC cells is indispensable of transforming growth factor-?1/Smad signaling. Instead, the activated MEK/ERK/SNAIL1 signaling largely accounted for celecoxib-induced EMT. Taken together, our study reveals the diverse impacts of Cox-2 inhibitors on EMT in NSCLC cells independent of Cox-2 inhibition, where celecoxib treatment leads to metastasis and chemoresistance via EMT induction. These findings reveal the increased risks of cancer metastasis and chemoresistance by applying Cox-2 inhibitors, celecoxib in particular, in clinical trials of NSCLC treatment and urge intensive preclinical assessment before proceeding to clinical application. PMID:23172668

Wang, Zi-li; Fan, Zhi-qiang; Jiang, Han-dong; Qu, Jie-ming

2013-03-01

31

A new class of acyclic 2-alkyl-1,2-diaryl (E)-olefins as selective cyclooxygenase-2 (COX-2) inhibitors.  

PubMed

A new class of (E)-2-alkyl-2-(4-methanesulfonylphenyl)-1-phenylethenes were designed for evaluation as selective cyclooxygense-2 (COX-2) inhibitors. The target olefins were synthesized, via a Takeda olefination reaction, followed by oxidation of the respective thiomethyl olefinic intermediate. In vitro COX-1/COX-2 inhibition studies identified (E)-2-(4-methanesulfonylphenyl)-1-phenyloct-1-ene (8d) as a potent (IC(50)=0.77 microM) and selective (Selectivity Index>130) COX-2 inhibitor. PMID:15341950

Uddin, Md Jashim; Rao, P N Praveen; Rahim, Md Abdur; McDonald, Robert; Knaus, Edward E

2004-10-01

32

Design and synthesis of novel celecoxib analogues as selective cyclooxygenase-2 (COX-2) inhibitors: replacement of the sulfonamide pharmacophore by a sulfonylazide bioisostere.  

PubMed

A group of celecoxib analogues in which the para-SO(2)NH(2) substituent on the N(1)-phenyl ring was replaced by a para-sulfonylazido (SO(2)N(3)) 4, or a meta-SO(2)N(3) 8, substituent were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 inhibition studies showed that 4-[5-(4-methylphenyl)-3-trifluoromethyl-1H-pyrazol-1-yl]benzenesulfonyl azide (4) with a para-SO(2)N(3) substituent was a selective COX-1 inhibitor. In contrast, 3-[5-(4-methylphenyl)-3-trifluoromethylpyrazol-1-yl]benzenesulfonyl azide (8a) having a meta-SO(2)N(3) substituent (COX-1 IC(50) >100microM; COX-2 IC(50)=5.16microM; COX-2 selectivity index >19.3) is a selective COX-2 inhibitor. A molecular modeling (docking) study showed that the SO(2)N(3) group of 8a inserts deep inside the secondary pocket of the COX-2 binding site. The SO(2)N(3) moiety of 8a can undergo a dual H-bonding interaction via one of its SO(2) oxygen-atoms, and an electrostatic (ion-ion) interaction via the terminal azido (N(3)) nitrogen-atom, to the guanidino NH(2) of Arg(513) in the secondary pocket of COX-2. These observations indicate that an appropriately positioned SO(2)N(3) moiety is a novel alternative bioisostere to the traditional SO(2)NH(2) and SO(2)Me pharmacophores present in selective COX-2 inhibitors, that are only capable of H-bonding interactions with the COX-2 isozyme, for use in drug design. PMID:14604691

Uddin, Md Jashim; Rao, P N Praveen; Knaus, Edward E

2003-11-17

33

COX-2 inhibitors: pharmacological data and adverse effects.  

PubMed

The nonsteroidal anti-inflammatory drugs (NSAIDs) cover a wide range of selectivity, from the nonselective cyclooxygenase (COX) inhibitors to the preferential COX-2, and the newest coxibs, selective COX-2, with 1000-fold selectivities for COX-2. Coxibs belong to the distinct classes of sulphonamides, methylsulphones, and phenylacetic acid derivatives. The affinity of an inhibitor for COX-1 and COX-2 determinates its relative selectivity. Minor changes in the amino acid structure between the 2 enzymes results in different forms of their active sites. However, the primitive hypothesis of a dualism between an isoform totally inducible (COX-2) and the other isoform constitutive (COX-1) was not completely true. Thus, also selective COX-2 inhibitors have been shown to interact with gastrointestinal, renal, and cardiovascular systems. New insights into pharmacological data and side effect profile of coxibs have been reported in this review. They may reduce gastrointestinal-related risks, but when administered with low-dose aspirin, they could create an ulcerogenic dual-COX inhibitor. Moreover, by inhibiting COX-2, they could delay ulcer healing. Similarly to traditional NSAIDs, coxibs compromise the glomerular filtration rate in patients at increased risk, and may cause peripheral oedema and hypertension. According to the traditional ''COX-2 hypothesis'', they should not impair efficacy of coagulation. However, in combination with an oral anticoagulant they increase the International Normalized Ratio (INR) and, in some cases, cause bleeding. The altered balance between prostacyclin and thromboxane, due to selective inhibition of COX-2 without reducing COX-1, could promote a prothrombotic state and explain the observed increased cardiovascular risk. Finally, the role of COX-2 expression in the ischemic preconditioning mechanism and the recent discovery of a pro-oxidant activity of sulphones has been analysed. PMID:16012420

Mattia, C; Coluzzi, F

2005-01-01

34

Design and synthesis of celecoxib and rofecoxib analogues as selective cyclooxygenase-2 (COX-2) inhibitors: replacement of sulfonamide and methylsulfonyl pharmacophores by an azido bioisostere.  

PubMed

Celecoxib (13) and rofecoxib (17) analogues, in which the respective SO2NH2 and SO2Me hydrogen-bonding pharmacophores were replaced by a dipolar azido bioisosteric substituent, were investigated. Molecular modeling (docking) studies showed that the azido substituent of these two analogues (13, 17) was inserted deep into the secondary pocket of the human COX-2 binding site where it undergoes electrostatic interaction with Arg(513). The azido analogue of rofecoxib (17), the most potent and selective inhibitor of COX-2 (COX-1 IC(50) = 159.7 microM; COX-2 IC(50) = 0.196 microM; COX-2 selectivity index = 812), exhibited good oral antiinflammatory and analgesic activities. PMID:11520213

Habeeb, A G; Praveen Rao, P N; Knaus, E E

2001-08-30

35

Therapy switching and associated costs in elderly patients receiving COX2 selective inhibitors or non-selective non-steroidal anti-inflammatory drugs in Quebec, Canada  

Microsoft Academic Search

Objectives. Lack of efficacy or tolerability of some non-steroidal anti-inflammatory drugs (NSAIDs) may lead to switching between non-selective NSAIDs (nsNSAIDs) and cyclooxygenase-2 (COX-2) selective inhibitors (coxibs), potentially increasing treatment costs due to additional physician visits and wastage of medication. This study assessed drug switching and associated costs among elderly chronic NSAID users. Methods. Data for patients who filled their first

E. Rahme; Y. Toubouti; E. Hunsche

2006-01-01

36

Design and synthesis of new water-soluble tetrazolide derivatives of celecoxib and rofecoxib as selective cyclooxygenase-2 (COX-2) inhibitors.  

PubMed

In an attempt to prepare a new water-soluble, parenteral COX-2 inhibitor, rofecoxib (9) and celecoxib (13) analogues were designed and synthesized for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors with in vivo anti-inflammatory activity. In this experiment, respective SO(2)Me and SO(2)NH(2) hydrogen-bonding pharmacophores were replaced by a tetrazole ring. Molecular modeling (docking) studies showed that the tetrazole ring of these two analogues (9 and 13) was inserted deep into the secondary pocket of the human COX-2 binding site where it undergoes electrostatic interaction with Arg(513). The rofecoxib (9) and celecoxib (13) analogues exhibited a high in vitro selectivity (9, COX-1 IC(50) = 3.8 nM; COX-2 IC(50) = 1.8 nM; SI = 2.11; 13, COX-1 IC(50) = 4.1 nM; COX-2 IC(50) = 1.9 nM; SI = 2.16) relative to the reference drug celecoxib (COX-1 IC(50) = 3.7 nM; COX-2 IC(50) = .2 nM; SI=1.68) and also showed high aqueous solubility at pH higher than 7 and good anti-inflammatory activity in a carrageenan-induced rat paw edema assay. However, 9 and 13 had no significant damage on gastric mucosa. PMID:16806914

Navidpour, Latifeh; Amini, Mohsen; Shafaroodi, Hamed; Abdi, Khosrou; Ghahremani, Mohammad H; Dehpour, Ahmad Reza; Shafiee, Abbas

2006-09-01

37

Potential cardiovascular effects of COX-2 selective nonsteroidal antiinflammatory drugs.  

PubMed

The newly developed nonsteroidal antiinflammatory drugs (NSAIDs) that selectively inhibit cyclooxygenase-2 (COX-2), are effective against pain and inflammation and appear to have less gastrointestinal toxicity than conventional NSAIDs. Their COX-2 selectivity, however, has raised concerns regarding their cardiovascular safety, since they do not inhibit COX-1, the isoform of the enzyme that is active in thrombosis and vasoconstriction. At this point there is no conclusive evidence that COX-2 inhibitors cause ischemic vascular events, because retrospective post hoc analyses conflict one another, and no specific randomized trials have yet been done. Renal effects, edema and hypertension appear to be similar between conventional NSAIDs and COX-2-selective inhibitors. Aspirin is still required for patients with cardiovascular risk who are prescribed a COX-2-selective inhibitor. PMID:14649387

Fowles, Robert E

2003-01-01

38

Synthesis, biological evaluation and molecular modeling study of pyrazole and pyrazoline derivatives as selective COX-2 inhibitors and anti-inflammatory agents. Part 2.  

PubMed

New pyrazole and pyrazoline derivatives have been synthesized and their ability to inhibit ovine COX-1/COX-2 isozymes was evaluated using in vitro cyclooxygenase (COX) inhibition assay. Among the tested compounds, N-((5-(4-chlorophenyl)-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)methylene)-3,5-bis(trifluoromethyl)aniline 8d exhibit optimal COX-2 inhibitory potency (IC(50)=0.26 lM) and selectivity (SI)=>192.3] comparable with reference drug celecoxib (IC(50) value of 0.28 lM and selectivity index of 178.57). Moreover, the anti-inflammatory activity of selected compounds, which are the most selective COX-2 inhibitors in the COX inhibition assay, was investigated in vivo using carrageenan-induced rat paw edema model. Molecular modeling was conducted to study the ability of the active compounds to bind into the active site of COX-2 which revealed a similar binding mode to SC-558, a selective COX-2 inhibitor. PMID:22516672

El-Sayed, Magda A-A; Abdel-Aziz, Naglaa I; Abdel-Aziz, Alaa A-M; El-Azab, Adel S; ElTahir, Kamal E H

2012-05-15

39

Dual, but not selective, COX-1 and COX-2 inhibitors, attenuate acetic acid-evoked bladder irritation in the anaesthetised female cat.  

PubMed

Non-selective cyclooxygenase (COX) inhibitors exert effects on lower urinary tract function in several species. The exact contributions of COX-1 and COX-2 isozymes have not been studied much. The present studies investigated the effects of non- and selective COX inhibitors on bladder irritation in the cat.Chloralose-anaesthetised female cats were catheterised through the bladder dome for cystometric evaluation of bladder responses to intravesical infusion of saline or acetic acid. Bladder capacity, voiding efficiency, threshold pressure, and reflex-evoked bladder contraction amplitude and duration were measured. The cat COX selectivity of the doses of inhibitors examined was determined using an in vitro whole-blood assay and analysis of plasma levels. Pretreatment with indomethacin or ketoprofen (non-selective COX inhibitors; 0.3 mg kg(-1) i.v.) inhibited acetic acid-evoked irritation (characterised by a decrease in bladder capacity in vehicle pretreated animals). FR-122047 (selective COX-1 inhibitor), NS-398 and nimesulide (selective COX-2 inhibitors; 1 and 3 mg kg(-1) i.v.) had no effects on bladder irritation. Analysis of plasma levels of the doses examined and determination of COX-1 and COX-2 inhibition in cat whole blood confirmed the reported selectivity of these compounds in this species. The present studies suggest that dual COX inhibition is required to attenuate acetic acid-evoked bladder irritation in the cat. PMID:16547526

Wibberley, Alexandra; McCafferty, Gerald P; Evans, Christopher; Edwards, Richard M; Hieble, J Paul

2006-05-01

40

Design, synthesis, and biological evaluation of substituted 3-alkylthio-4,5-diaryl-4 H-1,2,4-triazoles as selective COX2 inhibitors  

Microsoft Academic Search

A new type of 4,5-diaryl-4H-1,2,4-triazole, possessing C-3 thio and alkylthio (SH, SMe or SEt) substituents, was designed and synthesized for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors with in vivo anti-inflammatory activity. The compound, 3-ethylthio-5-(4-fluorophenyl)-4-(4-methylsulfonylphenyl)-4H-1,2,4-triazole (10d), exhibited a high in vitro selectivity (COX-1 IC50=20.5nM; COX-2 IC50=1.8nM; SI=11.39) relative to the reference drug celecoxib (COX-1 IC50=3.7nM; COX-2 IC50=2.2nM; SI=1.68) and also showed

Latifeh Navidpour; Hamed Shafaroodi; Khosrou Abdi; Mohsen Amini; Mohammad H. Ghahremani; Ahmad Reza Dehpour; Abbas Shafiee

2006-01-01

41

Cox-2 inhibitors: today and tomorrow.  

PubMed

The elucidation of inducible cyclooxygenase (Cox-2) dependent inflammatory pathways led to the development of specific Cox-2 inhibitors, the coxibs. These agents include the currently available celecoxib and rofecoxib and such second-generation agents as parecoxib, valdecoxib, and etoricoxib. The therapeutic advantage of coxibs is founded primarily in their lack of significant gastrointestinal (GI) side effects. Clinical trials have demonstrated the efficacy of coxibs to be completely comparable with traditional nonsteroidal anti-inflammatory drugs (NSAIDs), and pharmacoeconomics suggest favorable cost/benefit ratios with these agents compared with traditional NSAIDs, related to their reduced GI complication profiles and lower indirect costs associated with disability. Although several clinical questions remain (eg, use with low-dose aspirin, risk of thrombosis, myocardial infarction, edema, and hypertension), the emergence and clinical utility of coxibs is likely to continue on the basis of their efficacy and relative GI safety advantage. Although newer, more specific Cox-2 inhibitors may alter the choice, it is likely that this class of anti-inflammatories will become (if they have not already) the drugs of first choice in the treatment of acute pain, chronic pain, and most rheumatic conditions in the 21st century. In addition to the treatment of rheumatic conditions, it is possible that coxibs will also be of clinical utility in protection against malignant transformation and Alzheimer disease. PMID:12003372

McMurray, Robert W; Hardy, Kenneth J

2002-04-01

42

Enhancement of glioblastoma radioresponse by a selective COX-2 inhibitor celecoxib: Inhibition of tumor angiogenesis with extensive tumor necrosis  

SciTech Connect

Purpose: Toward improved glioblastoma multiforme treatment, we determined whether celecoxib, a selective cyclooxygenase (COX)-2 inhibitor, could enhance glioblastoma radiosensitivity by inducing tumor necrosis and inhibiting tumor angiogenesis. Methods and Materials: U-87MG cells treated with celecoxib, irradiation, or both were assayed for clonogenic survival and angiogenic factor protein analysis (angiopoietin-1, angiopoietin-2, and vascular endothelial growth factor [VEGF]). In vivo, survival of mice intracranially implanted with U-87MG cells and treated with celecoxib and/or irradiation was monitored. Isolated tumors were assessed for tumor necrosis and tumor microvascular density by von Williebrand's factor (vWF) immunohistochemical staining. Results: Celecoxib (4 and 30 {mu}M; 24, 48, and 72 h) enhanced U-87MG cell radiosensitivity by significantly reducing clonogenic survival of irradiated cells. Angiopoietin-1 and VEGF proteins were decreased, whereas angiopoietin-2 expression increased after 72 h of celecoxib alone and when combined with irradiation. In vivo, median survival of control mice intracranially implanted with U-87MG cells was 18 days. Celecoxib (100 mg/kg/day, 2 weeks) significantly extended median survival of irradiated mice (24 Gy total) from 34 to 41 days, with extensive tumor necrosis [24.5 {+-} 8.6% of tumor region, compared with irradiation alone (2.7 {+-} 1.8%)]. Tumor microvascular density was significantly reduced in combined celecoxib and irradiated tumors (52.5 {+-} 2.9 microvessels per mm{sup 2} tumor region), compared with irradiated tumors alone (65.4 {+-} 4.0 microvessels per mm{sup 2}). Conclusion: Celecoxib significantly enhanced glioblastoma radiosensitivity, reduced clonogenic survival, and prolonged survival of glioblastoma-implanted mice by inhibition of tumor angiogenesis with extensive tumor necr0010os.

Kang, Khong Bee [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore)]. E-mail: dmskkb@nccs.com.sg; Wang, Ting Ting [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore); Woon, Chow Thai [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore); Cheah, Elizabeth S. [Department of Pathology, Singapore General Hospital (Singapore); Moore, Xiao Lei [Baker Heart Research Institute, Melbourne (Australia); Zhu Congju [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore); Wong, Meng Cheong [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore) and National Neuroscience Institute, Singapore General Hospital Campus (Singapore)

2007-03-01

43

Synthesis, Anti-Inflammatory and Anti- Nociceptive Activities and Cytotoxic Effect of Novel Thiazolidin-4-ones Derivatives as Selective Cyclooxygenase (COX-2) Inhibitors  

PubMed Central

Objective(s): Nowadays, COX-2 inhibitors such as valdecoxib are removed from the market because of their cardiovascular toxicity and their potential to increase the risk of strokes. In response to this, medicinal chemists have attempted to synthesize new classes of COX-2 Inhibitors. Materials and Methods: In this study, three novel analogues of thiazolidin-4-ones derivatives 2a-c were synthesized. The ability of these compounds to inhibit ovine COX-1 and COX-2 (0.2- 0.8 µM) was determined using a colorimetric method. The cytotoxic effect of the synthesized compounds (25-100 M) was also investigated by measuring their cytotoxicity against Caco-2 and MCF-7 cell lines using MTT assay. Cell apoptosis was determined by ?ow cytometry. Writhing test (7.5-75 mg/kg) was used to examine the antinociceptive effects in mice. The effect of the analogues against acute inflammation (7.5-75 mg/kg) was also studied using xylene-induced ear edema test in mice. Results: The synthesized compounds showed a weak capacity to inhibit the proliferation of Caco-2 and MCF-7 cell lines. The COX-2 inhibition potency and selectivity index for test compounds 2a–b were as follows; celecoxib > 2b > 2a. On the other hand, all three analogues exhibited strong antinociceptive activity against acetic acid-induced writhing. The anti-inflammatory and antinociceptive effects of the analogues were markedly more than positive control, celecoxib. Conclusion: This study demonstrates that the antinociceptive and anti-inflammatory activity profiles exhibited by the novel synthesized compounds are independent from their COX-2 inhibitory potencies. The found antinociceptive and anti-inflammatory effects can be caused by interaction with other target; independent from COX-2. Accordingly, the compounds 2a-c could serve as lead compounds to develop novel anti-inflammation and antinociceptive drugs. PMID:24570829

Moallem, Seyed Adel; Imenshahidi, Mohsen; Shahini, Narges; Javan, Ahmad Reza; Karimi, Mohsen; Alibolandi, Mona; Ghandadi, Morteza; Etemad, Leila; Motamedshariaty, Vahidehsadat; Hosseini, Toktam; Hadizadeh, Farzin

2013-01-01

44

The second generation of COX-2 inhibitors: what advantages do the newest offer?  

PubMed

The discovery of two cyclooxygenase (COX)-isoenzymes, a constitutive COX-1, serving homeostatic prostanoid synthesis, and an inducible COX-2, responsible for proinflammatory prostanoid production, led to the development of new non-steroidal anti-inflammatory drugs (NSAIDs), the selective COX-2 inhibitors, promising minimal NSAID-typical toxicity with full anti-inflammatory efficacy. So far, the strategy of selective COX-2 inhibition has been successful. Selective COX-2 inhibitors have significantly less gastrotoxicity and no effects on platelet aggregation. However, with regard to renal adverse events, selective COX-2 inhibitors do not offer a clinically relevant advantage over non-selective inhibitors. Moreover, concerns over the cardiovascular risk of selective COX-2 inhibitors have recently been raised. The second generation of COX-2 inhibitors with higher COX-2 selectivity was developed with the promise of further reduction of NSAID-typical adverse effects. The leading compounds are valdecoxib, parecoxib, etoricoxib and lumaricoxib. At the present time they have proven efficacy for the treatment of pain and inflammation. Parecoxib as a parenteral, highly selective COX-2 inhibitor has the potential to become the NSAID of choice for treatment of postoperative pain. In clinical trials, valdecoxib, parecoxib, etoricoxib and lumaricoxib have caused no more endoscopic ulcers than placebo. However, to date, no data on the clinically relevant endpoints perforation, symptomatic ulcer and bleeding are available. Furthermore, no definite conclusions on renal and cardiovascular safety are possible. Current evidence points to a marginal, if any, gain of safety compared with the first generation of COX-2 inhibitors. However, trials with the new COX-2 inhibitors offer the chance to address these open questions of highly selective COX-2 inhibition; that is, thrombogenic risk, sodium and water retention, and interference with tissue repair, in particular, healing of mucosal damage. PMID:12487621

Stichtenoth, Dirk O; Frölich, Jürgen C

2003-01-01

45

In vitro and in vivo profile of 2-(3-di-fluoromethyl-5-phenylpyrazol-1-yl)-5-methanesulfonylpyridine, a potent, selective, and orally active canine COX-2 inhibitor.  

PubMed

The synthesis of a novel canine COX-2 selective inhibitor, 2-(3-difluoromethyl-5-phenylpyrazol-1-yl)-5-methanesulfonylpyridine, and its in vitro and in vivo profile are described. Pyrazole 8 demonstrated excellent potency and selectivity for canine COX-2 in both in vitro and ex vivo whole blood assays. This novel COX-2 inhibitor also showed a good pharmacokinetic profile (pk) following oral (po), intravenous (iv), and subcutaneous (sc) dosing and demonstrated excellent in vivo efficacy in a canine synovitis model. PMID:15698798

Li, Jin; Lynch, Michael P; Demello, Kristin Lundy; Sakya, Subas M; Cheng, Hengmiao; Rafka, Robert J; Bronk, Brian S; Jaynes, Burton H; Kilroy, Carolyn; Mann, Donald W; Haven, Michelle L; Kolosko, Nicole L; Petras, Carol; Seibel, Scott B; Lund, Lisa A

2005-03-01

46

Molecular characterization, biological activity, and in silico study of 2-(3,4-dimethoxyphenyl)-3-(4-fluorophenyl)-6-methoxy-4H-chromen-4-one as a novel selective COX-2 inhibitor  

NASA Astrophysics Data System (ADS)

The present study aimed to characterize and investigate 2-(3,4-dimethoxyphenyl)-3-(4-fluorophenyl)-6-methoxy-4H-chromen-4-one (22) as a novel selective COX-2 inhibitor. The data collected from the single X-ray crystallographic analysis and in silico study provide important insights on the molecular conformation and the binding interactions that are responsible for the COX-2 selectivity.

Rullah, Kamal; Mohd Aluwi, Mohd Fadhlizil Fasihi; Yamin, Bohari M.; Baharuddin, Mohd Syukri; Ismail, Nor Hadiani; Teruna, Hilwan Yuda; Bukhari, Syed Nasir Abbas; Jantan, Ibrahim; Jalil, Juriyati; Husain, Khairana; Wai, Lam Kok

2015-02-01

47

Synthesis, biological evaluation, and docking analysis of a novel family of 1-methyl-1H-pyrrole-2,5-diones as highly potent and selective cyclooxygenase-2 (COX-2) inhibitors.  

PubMed

As a continuous research for discovery of new COX-2 inhibitors, we present the simple chemical synthesis, in vitro biological screening, and molecular docking study of 1H-pyrrole-2,5-dione derivatives. New synthetic compounds were evaluated for the inhibitory activities on LPS-induced PGE2 production in RAW 264.7 macrophage cells as well as the COX-1 and COX-2 inhibitory potency. Among them, compound 9d (MPO-0029) was identified as more potent and selective COX-2 inhibitor [PGE2 IC50=8.7 nM, COX-2 IC50=6.0 nM; COX-2 selectivity index (SI)=>168] than celecoxib. Molecular docking experiments were further performed against COX-2 and COX-1 isozymes to determine their probable binding models. Results of molecular docking studies revealed that compound 9d (MPO-0029) has stronger binding interaction with COX-2 than with COX-1 isozyme, and provided successfully complementary theoretical support for the obtained experimental biological data. PMID:24656662

Kim, Kyung Ju; Choi, Min Ji; Shin, Ji-Sun; Kim, Minju; Choi, Hye-Eun; Kang, Seoung Mook; Jin, Jae Ho; Lee, Kyung-Tae; Lee, Jae Yeol

2014-04-15

48

Apoptotic effects of two COX-2 inhibitors on breast adenocarcinoma cells through COX-2 independent pathway.  

PubMed

Recently, much effort has been directed toward the search for compounds that influence apoptosis and to understand their mechanisms of action. Cyclooxygenase (COX)-2 inhibitors may induce apoptosis through the COX-2-independent mechanism via a mitochondrial pathway. In view of the reported antiproliferative activities of two COX-2 inhibitor derivatives (1, 2) in breast cancer cells (MCF-7), the present study was undertaken to evaluate the potential of these compounds to induce apoptosis and unravel the associated mechanisms. The apoptotic activities of the two compounds were assessed using flow cytometry, fluorescence microscope, and Western blot analysis. Compounds 1 and 2-treated MCF-7 cells revealed the apoptotic cell death, as confirmed by the changes in nuclear morphology and the increased annexin-V/PI staining. Elevation of Bax to Bcl-2 ratio and activation of caspase-3 were found to be associated with the initiation of apoptosis induced by compound 1. Further investigation showed that compounds 1 and 2 inhibited NF-?B, FHC, and ERK activation, while no dramatic change was revealed in c-Myc and EGR-1 levels. Our data suggest that induction of apoptosis by compounds 1 and 2 is not associated with COX-2 expression and occurs through the NF-?B pathway, which sequentially inhibits P-ERK and FHC expression. PMID:25142612

Norouzi, Mahnaz; Norouzi, Shaghayegh; Amini, Mohsen; Amanzadeh, Amir; Irian, Saeed; Salimi, Mona

2015-01-01

49

Pharmacological characterization of a selective COX-2 inhibitor MF-tricyclic, [3-(3,4-difluorophenyl)-4-(4-(methylsulfonyl)phenyl)-2-(5H)-furanone], in multiple preclinical species.  

PubMed

Selective type 2 cyclooxygenase (COX-2) inhibitors are often used in preclinical studies without potency and selectivity data in the experimental species. To address this issue, we assessed a selective COX-2 inhibitor MF-tricyclic in four commonly used species, namely mice, rats, guinea pigs and rabbits, in the present study. In both the guinea pig and rabbit whole blood assay, the compound inhibited lipopolysaccharide (LPS)-induced PGE(2) production with an IC(50) (COX-2) of 0.6 and 2.8 microM, respectively. By comparison, the compound displayed a much weaker activity on clot-induced formation of thromboxane with an IC(50) (COX-1) of >10 microM (guinea pigs) and 23 microM (rabbits). In keeping with the in vitro potency data, the compound significantly inhibited interleukin-1 beta (IL-1beta) -induced PGE(2) formation in the rabbit synovium at plasma concentrations near the whole blood assay IC(50) for COX-2 but much lower than that for COX-1. MF-tricyclic was also potent and selective toward COX-2 in mice, inhibiting carrageenan-induced PGE(2) accumulation in the air pouch dose-dependently (ED(50)=0.5 mg/kg) without affecting stomach PGE(2) levels. In rats, MF-tricyclic was found to be effective in three standard in vivo assays utilized for assessing COX-2 inhibitors, namely, LPS-induced pyresis, carrageenan-induced paw edema and adjuvant-induced arthritis at the doses that did not inhibit stomach PGE(2) levels. Similar to that in rats, the compound displayed pharmacological efficacy in mice, guinea pigs and rabbits when tested in the LPS pyresis model. Our data reveal that MF-tricyclic has the desired biochemical and pharmacological properties for selective COX-2 inhibition in all four test species. PMID:17316604

Rowland, Steven E; Clark, Patsy; Gordon, Robert; Mullen, Anne K; Guay, Jocelyne; Dufresne, Lynn; Brideau, Christine; Cote, Bernard; Ducharme, Yves; Mancini, Joseph; Chan, Chi-chung; Audoly, Laurent; Xu, Daigen

2007-04-10

50

4-(4-cycloalkyl/aryl-oxazol-5-yl)benzenesulfonamides as selective cyclooxygenase-2 inhibitors: enhancement of the selectivity by introduction of a fluorine atom and identification of a potent, highly selective, and orally active COX-2 inhibitor JTE-522(1).  

PubMed

A series of 4-(4-cycloalkyl/aryl-oxazol-5-yl)benzenesulfonamide derivatives were synthesized and evaluated for their abilities to inhibit cyclooxygenase-2 (COX-2) and cyclooxygenase-1 (COX-1) enzymes. In this series, substituent effects at the ortho position to the sulfonamide group on the phenyl ring were examined. Most substituents reduced or lost both COX-2 and COX-1 activities. In contrast, introduction of a fluorine atom preserved COX-2 potency and notably increased COX1/COX-2 selectivity. This work led to the identification of a potent, highly selective, and orally active COX-2 inhibitor JTE-522 [9d, 4-(4-cyclohexyl-2-methyloxazol-5-yl)-2-fluorobenzenesulfonamide], which is currently in phase II clinical trials for the treatment of rheumatoid arthritis, osteoarthritis, and acute pain. PMID:11906292

Hashimoto, Hiromasa; Imamura, Katsuaki; Haruta, Jun-ichi; Wakitani, Korekiyo

2002-03-28

51

Inhibition of constitutive and inducible cyclooxygenase activity in human platelets and mononuclear cells by NSAIDS and Cox 2 inhibitors  

Microsoft Academic Search

A range of NSAIDs and reported Cox 2 selective compounds were tested in human freshly isolated platelets and LPS-stimulated mononuclear cells to determine their potency and selectivity as inhibitors of constitutive (presumably Cox 1) and inducible (presumably Cox 2) cyclooxygenase respectively. All compounds tested were either equipotent at inhibiting constitutive and inducible cyclooxygenase or were selective for the inducible form.

C. J. Grossman; J. Wiseman; F. S. Lucas; M. A. Trevethick; P. J. Birch

1995-01-01

52

Is there an inhibitory effect of COX2 inhibitors on bone healing?  

Microsoft Academic Search

The use of the new selective cyclooxygenase-2 (COX-2) inhibitors (such as celecoxib and rofecoxib) for the treatment of pain and inflammation caused by fractures, cementless total joint replacements, soft tissue healing to bone, and spinal fusion surgeries has been controversial due to the convincing data collected from nonspecific NSAIDs such as indomethacin and naproxen regarding their inhibitory effects on bone

Andrew B Seidenberg; Yuehuei H An

2004-01-01

53

Lack of correlation between the central anti-nociceptive and peripheral anti-inflammatory effects of selective COX-2 inhibitor parecoxib.  

PubMed

Non-steroidal anti-inflammatory drugs (NSAIDs) are thought to exert their pharmacological actions by a common mechanism: inhibition of cyclooxygenase (COX)-mediated prostanoid synthesis. Yet, differences and dissociation between their analgesic and anti-inflammatory effects have not been related to this enzymatic mechanism but mainly to pharmacokinetic factors. Thus, we have compared the effects of an equieffective anti-inflammatory dose (6 mg/kg i.p.) of two NSAIDs with comparable spinal pharmacokinetics, ketoprofen (moderately preferential for COX-1) and parecoxib (selective COX-2), on the activation of spinal nociceptive neurons (measured as c-Fos expression) induced by carrageenan-induced acute inflammation in the rat paw. Both NSAIDs showed a similar anti-inflammatory effect when administered after carrageenan injection (post-treatment). Post-treatment with ketoprofen produced inhibition of c-Fos but parecoxib did not have any significant effect. In addition, parecoxib anti-inflammatory effect was greater than that of ketoprofen, when administered before carrageenan injection (pre-treatment). Paradoxically, pre-treatment with ketoprofen produced a greater inhibition of c-Fos expression than with parecoxib, in all lamina of ipsilateral dorsal horn of the lumbar spinal cord. This suggests that NSAIDs therapeutic profile is related to their selectivity for COX isoforms and COX-2 is involved in the initiation but not in the maintenance of nociceptive spinal activation, which depends on COX-1. PMID:19463915

Urdaneta, A; Siso, A; Urdaneta, B; Cardenas, R; Quintero, L; Avila, R; Suarez-Roca, H

2009-08-28

54

Quantitative structure-activity relationships for commercially available inhibitors of COX-2.  

PubMed

Quantitative structure activity relationship (QSAR) studies of selective COX-2 inhibitors of commercial interest (drugs in market and on clinical trials) were performed. The COX-2 inhibitory activity (pIC(50)=-logIC(50)) of these twelve compounds was correlated with nineteen descriptors including steric, electronic and constitutional parameters. pIC(50) activity showed high positive correlation with both volume and HOMO (Highest occupied molecular orbital). A Biparametric model was developed that included both these descriptors. The predictive capability (q(2)= 0.66) of this equation was satisfactory. So it can be used to design newer templates or modify existing templates. Volume is an important parameter for the selective COX-2 inhibitory activity, because the secondary pocket in the active site of this enzyme is bigger than the active site of COX-1 enzyme (by 17%). HOMO is a measure of the nucleophilicity of the molecule and a molecule with high HOMO energy is ready to donate its electrons and thus is more reactive than molecule with low values. Binding studies were performed between the COX-2 enzyme and these molecules. The inhibitory activity increased with decrease in binding energy (or interaction energy) between the compounds with the COX-2 enzyme (with a correlation coefficient = -0.65). Calculated Log BBB (Blood Brain barrier), Log P (octonol water partition) and HBD (hydrogen bond donor) values were in the acceptable range (i.e., BBB = -1 to 0.3; LogP= 0 to 5; HBD < 5). PMID:18336329

Sivakumar, P M; Doble, M

2008-03-01

55

Design and synthesis of (E)-1,1,2-triarylethenes: novel inhibitors of the cyclooxygenase-2 (COX-2) isozyme.  

PubMed

A novel class of acyclic 1,1,2-triaryl (E)-ethenes was designed that were synthesized via an (E)-selective Takeda olefination reaction. Among the group of compounds evaluated, (E)-2-(4-fluorophenyl)-1-(4-methylsulfonylphenyl)-1-phenylethene (10c) emerged as the most potent (COX-2 IC(50)=0.0316 microM), and selective (selectivity index>3164), COX-2 inhibitor. PMID:15603969

Uddin, Md Jashim; Rao, P N Praveen; McDonald, Robert; Knaus, Edward E

2005-01-17

56

Design, synthesis, and biological evaluation of N-acetyl-2-carboxybenzenesulfonamides: a novel class of cyclooxygenase-2 (COX-2) inhibitors.  

PubMed

N-Acetyl-2-carboxybenzenesulfonamide (11), and a group of analogues possessing an appropriately substituted-phenyl substituent (4-F, 2,4-F(2), 4-SO(2)Me, 4-OCHMe(2)) attached to its C-4, or C-5 position, were synthesized for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1/COX-2 inhibition studies showed that 11 is a more potent inhibitor (COX-1 IC(50)=0.06microM; COX-2 IC(50)=0.25microM) than aspirin (COX-1 IC(50)=0.35microM; COX-2 IC(50)=2.4microM), and like aspirin [COX-2 selectivity index (S.I.)=0.14], 11 is a nonselective COX-2 inhibitor (COX-2 S.I.=0.23). Regioisomers having a 2,4-difluorophenyl substituent attached to the C-4 (COX-2 IC(50)=0.087microM; COX-2 S.I. >1149), or C-5 (COX-2 IC(50)=0.77microM, SI>130), position of 11 exhibited the most potent and selective COX-2 inhibitory activity relative to the reference drug celecoxib (COX-1 IC(50)=33.1microM; COX-2 IC(50)=0.07microM; COX-2 S.I.=472). N-Acetyl-2-carboxybenzenesulfonamide (11, ED(50)=49 mg/kg), and its C-4 2,4-difluorophenyl derivative (ED(50)=91 mg/kg), exhibited superior antiinflammatory activity (oral dosing) in a carrageenan-induced rat paw edema assay compared to aspirin (ED(50)=129 mg/kg). These latter compounds exhibited comparable analgesic activity to the reference drug diflunisal, and superior analgesic activity compared to aspirin, in a 4% NaCl-induced abdominal constriction assay. A molecular modeling (docking) study indicated that the SO(2)NHCOCH(3) substituent present in N-acetyl-2-carboxy-4-(2,4-fluorophenyl)benzenesulfonamide, like the acetoxy substituent in aspirin, is suitably positioned to acetylate the Ser(530) hydroxyl group in the COX-2 primary binding site. The results of this study indicate that the SO(2)NHCOCH(3) pharmacophore present in N-acetyl-2-carboxybenzenesulfonamides is a suitable bioisostere for the acetoxy (OCOMe) group in aspirin. PMID:15755648

Chen, Qiao-Hong; Rao, P N Praveen; Knaus, Edward E

2005-04-01

57

Selective COX2 inhibition prevents progressive dopamine neuron degeneration in a rat model of Parkinson's disease  

Microsoft Academic Search

Several lines of evidence point to a significant role of neuroinflammation in Parkinson's disease (PD) and other neurodegenerative disorders. In the present study we examined the protective effect of celecoxib, a selective inhibitor of the inducible form of cyclooxygenase (COX-2), on dopamine (DA) cell loss in a rat model of PD. We used the intrastriatal administration of 6-hydroxydopamine (6-OHDA) that

Rosario Sánchez-Pernaute; Andrew Ferree; Oliver Cooper; Meixiang Yu; Anna-Liisa Brownell; Ole Isacson

2004-01-01

58

[COX-2 inhibitor non-steroidal anti-inflammatory drugs, myth or reality?].  

PubMed

The discovery of two isoforms of cyclooxygenase, Cox-1 constitutive and Cox-2 inducible, has prompted the development of new molecules with high Cox-2 selectivity. These new NSAIDs belong to the coxib class and have theoretically a better digestive tolerability than classical NSAID have. In Belgium, rofecoxib ((Vioxx) and celecoxib (Celebrex) are commercialized. Rofecoxib is indicated in the symptomatic treatment of osteoarthritis (12.5 to 25 mg/d) and celecoxib is indicated in osteoarthritis (200 mg/d) and in rheumatoid arthritis (200 to 400 mg/d). Several studies have demonstrated their efficacy, similarly to classical NSAID as diclofenac (Voltaren), naproxen (Naprosyne), ibuprofen (Brufen) and their superiority compared to placebo. Their safety profile for gastrointestinal events is proven in patients without ulcer history compared to classical NSAID. However, the concomitant use of aspirin decreases the benefit as demonstrated for celecoxib at 400 mg/d but not investigated for rofecoxib. The selective inhibition of Cox-2 with no effect on Cox-1 favors cardiovascular events in patients at risk. Other side effects are similar to classical NSAID. Thus Cox-2 inhibitors NSAID are interesting molecules for their sparing gastrointestinal activity. They must be used with caution in patients with ulcer history, in the elderly and in patients requiring aspirin for cardiovascular prophylaxis. PMID:11680204

Peretz, A

2001-09-01

59

Design and synthesis of acyclic triaryl (Z)-olefins: a novel class of cyclooxygenase-2 (COX-2) inhibitors.  

PubMed

A group of acyclic 2-alkyl-1,1-diphenyl-2-(4-methylsulfonylphenyl)ethenes was designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 isozyme inhibition structure-activity studies identified 1,1-diphenyl-2-(4-methylsulfonylphenyl)hex-1-ene as a highly potent (IC(50) = 0.014 microM), and an extremely selective [COX-2 selectivity index (SI) > 7142], COX-2 inhibitor that showed superior anti-inflammatory (AI) activity (ID(50) = 2.5 mg/kg) relative to celecoxib (ID(50) = 10.8 mg/kg). This initial study was extended to include the design of a structurally related group of acyclic triaryl (Z)-olefins possessing an acetoxy (OAc) substituent at the para-position of the C-1 phenyl ring that is cis to a C-2 4-methylsulfonylphenyl substituent. COX-1 and COX-2 inhibition studies showed that (Z)-1-(4-acetoxyphenyl)-1-phenyl-2-(4-methylsulfonylphenyl)but-1-ene [(Z)-13b] is a potent (COX-1 IC(50) = 2.4 microM; COX-2 IC(50) = 0.03 microM), and selective (COX-2 SI = 81), COX-2 inhibitor which is a potent AI agent (ID(50) = 4.1mg/kg) with equipotent analgesic activity to celecoxib. A molecular modeling (docking) study showed that the SO(2)Me substituent of (Z)-13b inserts deep inside the 2 degrees -pocket of the COX-2 active site, where one of the O-atoms of SO(2) group undergoes a H-bonding interaction with Phe(518). The p-OAc substituent on the C-1 phenyl ring is oriented in a hydrophobic pocket comprised of Met(522), Gly(526), Trp(387), Tyr(348), and Tyr(385), and the C-2 ethyl substituent is oriented towards the mouth of the COX-2 channel in the vicinity of amino acid residues Arg(120), Leu(531), and Val(349). Structure-activity data acquired indicate that a (Z)-olefin having cis C-1 4-acetoxyphenyl (phenyl) and C-2 4-methylsulfonylphenyl substituents, and a C-1 phenyl substituent in conjunction with either a C-2 hydrogen or short alkyl substituent provides a novel template to design acyclic olefinic COX-2 inhibitors that, like aspirin, have the potential to acetylate COX-2. PMID:15498669

Uddin, Md Jashim; Rao, P N Praveen; Knaus, Edward E

2004-11-15

60

Virtual screening of 2,3-disubstituted-4(3H)-quinazolinones possessing benzenesulfonamide moiety for COX-2 inhibitor.  

PubMed

COX inhibitors which selectively inhibits the inducible COX-2 is an oenzyme that causes inflammation. They are clinically effective anti-inflammatory agents with less gastrointestinal and renal toxicity. However, they lack anti-thrombotic activity and hence lead to increased incidences of adverse cardiovascular trombotic events such as myocardial infarction. Therefore, there is still a need to develop better therapeutic effect and tolerability COX-2 inhibitor. The majority of COX-2 inhibitors are diaryl heterocycles. For optimum COX-2 selectivity and inhibitory potency a -SO(3)CH(3) or a- SO(2)NH(2) substituent at the para-position of phenyl ring was essential. A wide variety of heterocycles can serve as central ring system of the diaryl heterocycles structures. We report the screening of various 2,3-disubstituted-4(3H)-quinazolinones possessing benzenesulfonamide moiety, directly or indirectly bound to the ring system, using the Protein-Ligand ANT System (PLANTS) docking software against the COX-2 enzyme. Various molecular structures of ligands were docked and scored to identify structurally similar ligands to SC-558 (reference ligand) in binding interaction to COX-2 binding site. The results show that 2,3-disubstituted-4(3H)-quinazolinones possess pbenzenesulfonamide moiety at C-2, and phenyl moiety at N-3 binds directly or indirectly to the ring system with high binding affinity. The docked ligand has orientations similar to that observed with SC-558 satisfying Lipinski's rule of five. PMID:22125393

Hayun; Yanuar, Arry; Hanafi, Muhammad; Pws, Sumi Hudiyono

2011-01-01

61

Cellular and molecular studies of the effects of a selective COX-2 inhibitor celecoxib in the cardiac cell line H9c2 and their correlation with death mechanisms  

PubMed Central

Cardiovascular disease is one of the leading causes of death worldwide, and evidence indicates a correlation between the inflammatory process and cardiac dysfunction. Selective inhibitors of cyclooxygenase-2 (COX-2) enzyme are not recommended for long-term use because of potentially severe side effects to the heart. Considering this and the frequent prescribing of commercial celecoxib, the present study analyzed cellular and molecular effects of 1 and 10 µM celecoxib in a cell culture model. After a 24-h incubation, celecoxib reduced cell viability in a dose-dependent manner as also demonstrated in MTT assays. Furthermore, reverse transcription-polymerase chain reaction analysis showed that the drug modulated the expression level of genes related to death pathways, and Western blot analyses demonstrated a modulatory effect of the drug on COX-2 protein levels in cardiac cells. In addition, the results demonstrated a downregulation of prostaglandin E2 production by the cardiac cells incubated with celecoxib, in a dose-specific manner. These results are consistent with the decrease in cell viability and the presence of necrotic processes shown by Fourier transform infrared analysis, suggesting a direct correlation of prostanoids in cellular homeostasis and survival. PMID:24519091

Sakane, K.K.; Monteiro, C.J.; Silva, W.; Silva, A.R.; Santos, P.M.; Lima, K.F.; Moraes, K.C.M.

2014-01-01

62

Substrate-selective COX-2 inhibition as a novel strategy for therapeutic endocannabinoid augmentation.  

PubMed

Pharmacologic augmentation of endogenous cannabinoid (eCB) signaling is an emerging therapeutic approach for the treatment of a broad range of pathophysiological conditions. Thus far, pharmacological approaches have focused on inhibition of the canonical eCB inactivation pathways - fatty acid amide hydrolase (FAAH) for anandamide and monoacylglycerol lipase (MAGL) for 2-arachidonoylglycerol. We review here the experimental evidence that cyclooxygenase-2 (COX-2)-mediated eCB oxygenation represents a third mechanism for terminating eCB action at cannabinoid receptors. We describe the development, molecular mechanisms, and in vivo validation of 'substrate-selective' COX-2 inhibitors (SSCIs) that prevent eCB inactivation by COX-2 without affecting prostaglandin (PG) generation from arachidonic acid (AA). Lastly, we review recent data on the potential therapeutic applications of SSCIs with a focus on neuropsychiatric disorders. PMID:24845457

Hermanson, Daniel J; Gamble-George, Joyonna C; Marnett, Lawrence J; Patel, Sachin

2014-07-01

63

Nimesulide, a selective COX-2 inhibitor, acts synergistically with ionizing radiation against A549 human lung cancer cells through the activation of caspase-8 and caspase-3.  

PubMed

Several lines of evidence suggest that non-steroidal anti-inflammatory drugs (NSAIDs) have a radiosensitizing effect on cancer cells in vitro and in vivo, but little is known about the underlying cellular mechanism. In this study, we found that the treatment with the NSAID nimesulide significantly increased the sensitivity of A549 human non-small cell lung cancer cells to radiotherapy. The combined nimesulide-radiation treatment increased apoptosis, induced the cleavage of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP), activated caspase-8, and induced cleavage of Bid. A pan-caspase inhibitor, z-VAD-fmk, suppressed this increase in apoptosis and also suppressed the cleavage of caspase-8, caspase-3, and PARP, suggesting a caspase-dependent mechanism. In addition, z-IETD-fmk, a selective caspase-8 inhibitor, suppressed the nimesulide- and radiation-induced cleavage activation of caspase-9, caspase-3, caspase-8, and Bid, and suppressed the concomitant apoptosis, indicating that the nimesulide-induced increase in radiosensitivity was initiated by caspase-8. However, the caspase-3 inhibitor z-DEVD-fmk failed to suppress activation of the caspase-8/Bid pathway, indicating that caspase-3 activation occurred downstream of caspase-8 activation in our experiments. Marked antitumor effects, which were evaluated by measuring protracted tumor regression, were observed when nude mice were treated with a combination of nimesulide at a clinically achievable dose (0.5 mg/kg) and radiation therapy. Our results, demonstrating the radiosensitivity-increasing and tumor growth-inhibiting effects of nimesulide, suggest that nimesulide may be suitable as an adjuvant to enhance the efficacy and selectivity of radiotherapy. PMID:19360361

Kim, Byeong Mo; Won, Juyoon; Maeng, Kyung Ah; Han, Young Soo; Yun, Yeon-Sook; Hong, Sung Hee

2009-05-01

64

Novel pyrazoline derivatives as bi-inhibitor of COX-2 and B-Raf in treating cervical carcinoma.  

PubMed

Twenty four pyrazoline derivatives modified from Celecoxib were designed and synthesized as bi-inhibitor of COX-2 and B-Raf. They were evaluated for their COX-1/COX-2/B-Raf inhibitory and anti-proliferation activities. Compound A3 displayed the most potent activity against COX-2 and HeLa cell line (IC??=0.008 ?M; GI??=19.86 ?M) and showed superb COX-1/COX-2 selectivity (>500), being more potent and selective than positive control Celecoxib or 5-fluorouracil. Compounds A5 and B5 were introduced best B-Raf inhibitory activities (IC??=0.15 ?M and 0.12 ?M, respectively). Compound A4 retained superb bioactivity against COX-2 and HeLa cell line (IC??=0.015 ?M; GI??=23.82 ?M) and displayed moderate B-Raf inhibitory activity (IC??=3.84 ?M). Docking simulation was conducted to give binding patterns. QSAR models were built using bioactivity data and optimized conformations to provide a future modification of COX-2/B-Raf inhibitors. PMID:24934992

Yu, Minmin; Yang, Hui; Wu, Kaihua; Ji, Ying; Ju, Lili; Lu, Xiaoyuan

2014-08-01

65

Celecoxib exhibits the greatest potency amongst cyclooxygenase (COX) inhibitors for growth inhibition of COX-2-negative hematopoietic and epithelial cell lines.  

PubMed

Cyclooxygenase-2 (COX-2) is an important cellular target for both therapy and/or prevention of inflammatory disorders and cancer. The advent of selective COX-2 inhibitors now allows a more precise and safer treatment approach. The screening of an array of cancer cell lines for growth inhibitory effects of COX-2-selective and -nonselective inhibitors, including celecoxib (Celebrex) and rofecoxib (Vioxx), produced two unanticipated findings. Firstly, the antiproliferative effects of celecoxib were noted to be of very similar magnitude for both hematopoietic and epithelial cancer cell lines. Most hematopoietic cell lines had no detectable COX-2 expression by reverse transcription-PCR, and none expressed COX-2 protein. In addition, COX-2-negative epithelial lines were found to have IC50s for celecoxib that were very similar to their COX-2+ counterparts. Thus, important antiproliferative effects were observed that were independent of both the cell lineage and COX-2 status. Secondly, it was also observed that COX-2 inhibitor drugs, celecoxib and rofecoxib, with similar COX-2-selectivity and clinical efficacy for inflammatory indications, differed significantly in their in vitro antiproliferative effects on cancer cell lines. IC50s of 35-65 microM were observed for celecoxib across this entire panel of cell lines. Finally, no difference in the mode or degree of cytotoxicity was apparent between cell lines, because similar levels of apoptosis were observed in COX-2+ and -negative cell lines after treatment with celecoxib, with correspondingly lower levels after rofecoxib treatment. These data are important in that they provide the first direct comparison of epithelial and hematopoietic cancer cell lines, as well as a direct comparison of the in vitro anticancer effects of the two clinically available COX-2 inhibitors. PMID:11929821

Waskewich, Chris; Blumenthal, Rosalyn D; Li, Honglan; Stein, Rhona; Goldenberg, David M; Burton, Jack

2002-04-01

66

Going against the flow: the impact of PHARMAC not funding COX2 inhibitors for chronic arthritis  

Microsoft Academic Search

COX-2 inhibitors have come under a lot of scrutiny lately, with questions raised regarding class effects and the risk-benefit of these pharmaceuticals. From 1999 to 2003 the New Zealand Pharmaceutical Management Agency (PHARMAC) evaluated the evidence on COX-2 inhibitors, including their efficacy, cost-effectiveness and budgetary impact. In September 2003 PHARMAC decided not to list celecoxib, rofecoxib and meloxicam on the

Rachel Grocott; Scott Metcalfe

2005-01-01

67

Pharmacokinetic and pharmacodynamic aspects of the ideal COX-2 inhibitor: a pharmacologist's perspective.  

PubMed

Two classes of antipyretic analgesics were developed about 100 years ago, namely the acidic aspirin-like drugs and non-acidic acetaminophen-phenazone-like compounds. Since then, research has aimed at improving the side-effect profile of the acidic anti-inflammatory aspirin-like drugs and improving the anti-inflammatory efficacy of the non-acidic acetaminophen-phenazone-like compounds. Both drug classes inhibit the cyclooxygenase (COX)-1 and -2 enzymes non-selectively. The aspirin-like drugs achieve particularly high concentrations in inflamed tissue, which is assumed to account for their superior anti-inflammatory potency. These acidic drugs also reach comparatively high concentrations in the stomach wall, kidney cortex and blood, resulting in the well-known side effects that occur with acidic compounds but not with acetaminophen and phenazone. Following the discovery of the two differentially distributed and regulated COXs, two non-acidic COX-2-selective compounds--celecoxib and rofecoxib--were introduced. They proved to be less toxic to the gastrointestinal tract compared with, for example, diclofenac or naproxen. These non-acidic drugs distribute homogeneously throughout the body--a cause for concern since COX-2 has been found to be present constitutively in many organ systems, including brain, bone and the genito-urinary tract. It appears desirable to combine the tissue-targeted distribution of the highly protein-bound acidic aspirin-type drugs with the selectivity of the COX-2 inhibitors, in order to achieve improved anti-inflammatory activity and at the same time reduce the risk of side effects. Such agents should be devoid of COX-1-related side effects in, for example, the inhibition of blood coagulation and should only weakly affect COX-2 related functions of the central nervous system, due to slow blood-brain barrier penetration. We therefore propose that a drug combining the pharmacokinetic characteristics of, for example, ibuprofen with the COX-2 selectivity of rofecoxib is likely to be a superior anti-inflammatory analgesic. PMID:11695253

Brune, K; Neubert, A

2001-01-01

68

Antiproliferative effect of two novel COX-2 inhibitors on human keratinocytes.  

PubMed

Selective COX-2 inhibitors (COXib) belonging to the class of diaryl heterocycles (e.g., celecoxib, rofecoxib, etc.), are devoid of the undesirable effects due to their capacity to inhibit selectively inducible (COX-2), responsible for inflammatory effects but not constitutive cyclooxygenase-1 (COX-1)(COX); responsible for cytoprotective effects on gastric mucosa. In addition, several reports have identified an increased risk of cardiovascular events associated with the use of COXib. We have developed a new series of anti-inflammatory agents (1,5-diarylpyrrole-3-alkoxyethyl esters and ethers). To evaluate the effect of two 1,5-diarylpyrrole-3-alkoxyethyl ethers, VA441 and VA428 (up to 100 ?M), respectively, in comparison with two well known COXib, celecoxib and rofecoxib, on HaCaT cell (keratinocytes) proliferation and toxicity. Crucial molecules in cell cycle progression, i.e. NF?B and ERK as targets/mediators and cyclin D1 and p21 Cip1/Kip as final effectors were evaluated by Western blot, immunohystochemistry and q-PCR analysis. Both compounds, VA441 and VA428, showed a strong inhibition of cell proliferation, and did not exhibit cytotoxicity. The anti-proliferative effect was accompanied by a strong activation of ERK and induction of the cell cycle inhibitor p21. In addition, there was a clear inhibition of the transcription factor NF-?B and downregulation of cyclin D1, with enforced inhibition of the HaCaT cell cycle progression. These data suggest that compounds VA441 and VA428, along with their role in inhibiting COX-2 and inflammation, could have a possible therapeutic (topical and systemic) use against skin proliferative disorders, such as psoriasis. PMID:23454135

Sticozzi, Claudia; Belmonte, Giuseppe; Cervellati, Franco; Di Capua, Angela; Maioli, Emanuela; Cappelli, Andrea; Giordani, Antonio; Biava, Mariangela; Anzini, Maurizio; Valacchi, Giuseppe

2013-05-13

69

The COX-2 inhibitors, meloxicam and nimesulide, suppress neurogenesis in the adult mouse brain  

PubMed Central

Background and purpose: In adults, neurogenesis persists in the hippocampus and the subventricular zone (SVZ), and this is important for learning and memory. Inhibitors of COX-2 suppress ischaemia-induced neurogenesis in the hippocampus. Here, we have determined the effects of COX-2 inhibitors on neurogenesis throughout the normal adult mouse brain. Experimental approach: Young adult mice were treated with COX-2 inhibitors, and the proliferation of neural progenitor cells was measured in the SVZ and hippocampus. In addition, the local uptake of lentiviral vectors in the rostral migratory stream enabled the formation of new neurons in the olfactory bulb (OB) to be assessed. Key results: The COX-2 inhibitor meloxicam suppressed progenitor cell proliferation in the SVZ and hippocampus. A significant decrease in the appearance of new neurons in the OB was also observed. Similar effects on progenitor proliferation in the SVZ were seen with nimesulide. The absence of COX-2 expression in the proliferating progenitors in vivo, and the lack of effect of the COX-2 inhibitors on the growth rate of a cultured progenitor cell line, suggest that the effect is indirect. The specific expression of COX-2 in resting microglia that closely associate with the proliferating progenitor cells provides for a possible site of action. Conclusions and implications: Treatment with a COX-2 inhibitor results in a substantial inhibition of adult neurogenesis. Studies on human tissues are warranted in order to determine if this effect extends to humans, and whether inhibition of neurogenesis should be considered as an adverse effect of these drugs. PMID:20136845

Goncalves, Maria Beatriz; Williams, Emma-Jane; Yip, Ping; Yáñez-Muñoz, Rafael J; Williams, Gareth; Doherty, Patrick

2010-01-01

70

Inhibition of constitutive and inducible cyclooxygenase activity in human platelets and mononuclear cells by NSAIDs and Cox 2 inhibitors.  

PubMed

A range of NSAIDs and reported Cox 2 selective compounds were tested in human freshly isolated platelets and LPS-stimulated mononuclear cells to determine their potency and selectivity as inhibitors of constitutive (presumably Cox 1) and inducible (presumably Cox 2) cyclooxygenase respectively. All compounds tested were either equipotent at inhibiting constitutive and inducible cyclooxygenase or were selective for the inducible form. The most selective compound was Dup697 and the least selective, ketoprofen. Several compounds only produced a partial inhibition of constitutive cyclooxygenase as the maximum inhibitor concentration achievable in the assay was limited to 1 mM. With the exception of paracetamol, all compounds were able to produce full inhibition curves against the inducible form. Potency estimates against constitutive Cox compare closely with published data but most compounds were consistently more potent against the inducible isoform than in published data for human cloned, microsomal Cox 2. These data suggest that human mononuclear cells are either exquisitely sensitive to some NSAIDs or they may contain another Cox isoform as yet indistinguishable from Cox 2. PMID:7583521

Grossman, C J; Wiseman, J; Lucas, F S; Trevethick, M A; Birch, P J

1995-06-01

71

In vitro cytotoxic evaluation of some synthesized COX-2 inhibitor derivatives against a panel of human cancer cell lines  

PubMed Central

Celecoxib is a non-steroidal anti-inflammatory drug (NSAID) developed as a selective inhibitor of cyclooxygenase-2 (COX-2) for the treatment of rheumatoid arthritis disease. Recently some other mechanisms have been identified for anti cancer activity of these agents including induction of apoptosis, inhibition of tumor vascularization, stimulation of antitumor immune responses and inhibition of cellular protein synthesis. The cytotoxic effects of four synthesisized analogues of celecoxib (coded as D, E, F and G) were evaluated against Hela, MDA-MB-231, A-2780-s and HT-29 cancer cells, using MTT assay; Also their induction of apoptosis using DNA fragmentation analysis were studied. MTT assay showed that cell survival percent of COX-2 positive cell lines (HT-29, MDA-MB-231 and Hela; p?0.05) were decreased significantly after exposure to the tested COX-2 inhibitors while little effect was observed on the COX-2 negative cell line (A-2780-s). Results also showed that A-2780-s and Hela were the most resistant and the most sensitive cell lines to these compounds, respectively. Moreover, in DNA fragmentation assay, induction of apoptosis was confirmed by electrophoretic pattern of separated DNA fragments in Hela cell line. Compounds E and G in comparison with D and F exerted more cytotoxic effect on COX-2 positive cell lines (Hela, HT-29 and MDA-MB-231). This could be due to the hydrophobic substituent (Cl, CH3) located at the para position of phenyl ring leading to more lipophilicity and cell uptake. In addition, these COX-2 inhibitors induced apoptosis on Hela cell-line, which could be considered as one of the cytotoxic mechanisms of these compounds as potential anti cancer agents. PMID:24082899

Sadeghi-Aliabadi, H.; Aliasgharluo, M.; Fattahi, A.; Mirian, M.; Ghannadian, M.

2013-01-01

72

Antiinflammatory and neuroprotective actions of COX2 inhibitors in the injured brain  

PubMed Central

Overexpression of COX2 appears to be both a marker and an effector of neural damage after a variety of acquired brain injuries, and in natural or pathological aging of the brain. COX2 inhibitors may be neuroprotective in the brain by reducing prostanoid and free radical synthesis, or by directing arachidonic acid down alternate metabolic pathways. The arachidonic acid shunting hypothesis proposes that COX2 inhibitors' neuroprotective effects may be mediated by increased formation of potentially beneficial eicosanoids. Under conditions where COX2 activity is inhibited, arachidonic acid accumulates or is converted to eicosanoids via lipoxygenases and cytochrome P450 (CYP) epoxygenases. Several P450 eicosanoids have been demonstrated to have beneficial effects in the brain and/or periphery. We suspect that arachidonic acid shunting may be as important to functional recovery after brain injuries as altered prostanoid formation per se. Thus, COX2 inhibition and arachidonic acid shunting have therapeutic implications beyond the suppression of prostaglandin synthesis and free radical formation. PMID:17996418

Strauss, Kenneth I.

2008-01-01

73

In -silico molecular docking analysis of prodigiosin and cycloprodigiosin as COX-2 inhibitors.  

PubMed

Prodigiosin and cycloprodigiosin are tripyrrole red pigmented compounds with medical importance for their anticancer property. In the present investigation, molecular docking studies were performed for both prodigiosin and cycloprodigiosins to evaluate the in- silico anti-inflammatory activity against Cycloxigenase-2 (COX-2) protein as model compound and the data compared with rofecoxib and celcoxid. Cycloprodigiosin showed higher initial potential, initial RMS gradient and potential energy values compared to prodigiosin. Analysis of COX-2 protein and ligand binding revealed that cyclprodigiosin interacted with COX-2 protein amino acid residues of Tyr(324), Phe(487) and Arg(89) while prodigiosin interaction was observed with two amino acids i.e. Leu(321) and Tyr(324). The computational ligand binding interaction suggested > 45% higher fitness score value for prodigiosin to that of cycloprodigiosin with COX-2 protein while the standard compounds rofecoxib and celecoxid revealed fitness score of 44 and 62, respectively. The prodigiosin ligand revealed the best fitness score compared with the standard drug rofecoxib suggesting the prodigiosin could be effective as the potential inhibitor compound against COX-2 protein and can be evaluated as anti-inflammatory drug molecule using clinical trials. PMID:23741639

Krishna, Pabba Shiva; Vani, Kompally; Prasad, Metuku Ram; Samatha, Burra; Bindu, Nidadavolu Shesha Venkata Sathya Siva Surya Laxmi Hima; Charya, Maringanti Alaha Singara; Reddy Shetty, Prakasham

2013-12-01

74

O-desmethylquinine as a cyclooxygenase-2 (COX-2) inhibitors using AutoDock Vina  

NASA Astrophysics Data System (ADS)

Computational approach was employed to evaluate the biological activity of novel cyclooxygenase-2 COX-2 inhibitor, O-desmethylquinine, in comparison to quinine as common inhibitor which can also be used an agent of antipyretic, antimalaria, analgesic and antiinflamation. The molecular models of the compound were constructed and optimized with the density function theory with at the B3LYP/6-31G (d,p) level using Gaussian 09 program. Molecular docking studies of the compounds were done to obtain the COX-2 complex structures and their binding energies were analyzed using the AutoDock Vina. The results of docking of the two ligands were comparable and cannot be differentiated from the energy scoring function with AutoDock Vina.

Damayanti, Sophi; Mahardhika, Andhika Bintang; Ibrahim, Slamet; Chong, Wei Lim; Lee, Vannajan Sanghiran; Tjahjono, Daryono Hadi

2014-10-01

75

Direct-to-consumer advertising of COX-2 inhibitors: effect on appropriateness of prescribing.  

PubMed

Spending on direct-to-consumer advertising (DTCA) of prescription drugs has increased dramatically in the past several years. An unresolved question is whether such advertising leads to inappropriate prescribing. In this study, the authors use survey and administrative data to determine the association of DTCA with the appropriate prescribing of cyclooxygenase-2 (COX-2) inhibitors for 1,382 patients. Treatment with either a COX-2 or a traditional nonsteroidal anti-inflammatory drug (NSAID) was defined as appropriate or not according to three different definitions of gastrointestinal risk. Patients who saw or heard a COX-2 advertisement and asked their physician about the advertised drug were significantly more likely to be prescribed a COX-2 (versus a NSAID, as recommended by evidence-based guidelines) than all other patients. Findings also suggest that some patients may benefit from DTCA. The authors discuss the need for balanced drug information for consumers, increased physician vigilance in prescribing appropriately, and further study of DTCA. PMID:16177457

Spence, Michele M; Teleki, Stephanie S; Cheetham, T Craig; Schweitzer, Stuart O; Millares, Mirta

2005-10-01

76

The effect of COX2 specific inhibitors on blood pressure control in patients with osteoarthritis and hypertension  

Microsoft Academic Search

In treated hypertensive patients, NSAIDs may cause significant loss of blood pressure (BP) control, primarily systolic, through drug-drug\\/drug-disease interactions. It is not known whether COX-2 specific inhibitors, which spare renal COX-1, might have an effect on BP similar to that of conventional NSAIDs. To evaluate effects of COX-2 specific inhibitors on BP control in hypertensive OA patients at their most

Andrewm Whelton; William B. White; John G. Fort; Alfonso Bello

2002-01-01

77

Trimethyl-4-oxo-4,5,6,7-tetrahydroindazole-1-acetic acid: a new lead compound with selective COX-2 inhibitory activity.  

PubMed

A novel series of 3,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydroindazole-1-acetic acid derivatives was designed and synthesized by a new one-step pathway. Structure elucidation of the synthesized compounds was confirmed by various spectral and elemental analyses. The prepared compounds were evaluated for their ability to inhibit cyclooxygenase-2 (COX-2) and cyclooxygenase-1 (COX-1) enzymes in vitro. Among the synthesized compounds, the 2-(3,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydroindazol-1-yl)acetic acid 4 emerged as the most potent COX-2 inhibitor (IC(50) value: 150?nM) with the highest selectivity index (COX-1/COX-2 inhibition ratio: 570.6). Docking studies of compound 4 in the active site of COX-2 recognized its potential binding mode to the enzyme. Based on the preliminary results, compound 4 was considered as a lead compound for further optimization. PMID:22907715

Abdel-Rahman, Hamdy M; Ozadali, Keriman

2012-11-01

78

Analgesia and COX-2 inhibition.  

PubMed

While non-steroidal anti-inflammatory drugs (NSAIDs) are the mainstay of therapy for the management of acute pain and rheumatoid arthritis, toxicity associated with chronic administration limits their benefit-to-risk relationship in many patients. A series of studies is reviewed that assesses the relationship between cytokines released at the site of tissue injury and NSAID analgesia, and the in vivo selectivity of a selective cyclooxygenase (COX)-2 inhibitor (celecoxib) in comparison to a dual COX-1/COX-2 inhibitor (ketorolac). Three replicate studies in the oral surgery model of acute pain used submucosal microdialysis sample collection for the measurement of prostaglandin E2 (PGE2; a product of both COX-1 and COX-2) and thromboxane B2 (as a biomarker for COX-1 activity) with parallel assessments of pain. The time course of PGE2 production was consistent with early release due to COX-1 activity followed by increased production 2-3 hours after surgery, consistent with COX-2 expression. Ketorolac 30 mg at pain onset suppressed both pain and peripheral PGE2 levels. Ketorolac 1 mg either at the site of injury or intramuscularly also produced analgesia but without any effect on peripheral PGE2 levels. Celecoxib selectively suppressed PGE2 but not TxB2 at time points consistent with COX-2 activity, while producing analgesia. These studies demonstrate the ability to assess the time course and selective effects of COX-2 inhibitors in vivo and suggest that suppression of COX-2 mediated PGE2 is temporally related to NSAID analgesia. PMID:11695255

Dionne, R A; Khan, A A; Gordon, S M

2001-01-01

79

Improvement in gastrointestinal tolerability of the selective cyclooxygenase (COX)-2 inhibitor, meloxicam, compared with piroxicam: results of the Safety and Efficacy Large-scale Evaluation of COX inhibiting Therapies (SELECT) trial in osteoarthritis  

Microsoft Academic Search

SUMMARY Select is a large-scale, prospective, international, multicentre, double-blind, double-dummy, randomized, parallel-group trial. Patients with exacerbation of osteoarthritis were treated with the recommended dose of meloxicam (7.5 mg) or piroxicam (20 mg) once daily for 28 days; 4320 patients were administered meloxicam and 4336 piroxicam. The incidence of adverse events was significantly lower in the meloxicam group (22.5%) compared with

J. DEQUEKER; C. HAWKEY; A. KAHAN; K. STEINBRUCK; C. ALEGRE; E. BAUMELOU; B. BEGAUD; H. ISOMAKI; G. LITTLEJOHN; J. MAU; S. PAPAZOGLOU

1998-01-01

80

Enhancing the pharmacodynamic profile of a class of selective COX-2 inhibiting nitric oxide donors.  

PubMed

We report herein the development, synthesis, physicochemical and pharmacological characterization of a novel class of pharmacodynamic hybrids that selectively inhibit cyclooxygenase-2 (COX-2) isoform and present suitable nitric oxide releasing properties. The replacement of the ester moiety with the amide group gave access to in vivo more stable and active derivatives that highlighted outstanding pharmacological properties. In particular, the glycine derivative proved to be extremely active in suppressing hyperalgesia and edema. PMID:24373735

Biava, Mariangela; Battilocchio, Claudio; Poce, Giovanna; Alfonso, Salvatore; Consalvi, Sara; Di Capua, Angela; Calderone, Vincenzo; Martelli, Alma; Testai, Lara; Sautebin, Lidia; Rossi, Antonietta; Ghelardini, Carla; Di Cesare Mannelli, Lorenzo; Giordani, Antonio; Persiani, Stefano; Colovic, Milena; Dovizio, Melania; Patrignani, Paola; Anzini, Maurizio

2014-01-15

81

Nanoemulsion-based gel formulations of COX-2 inhibitors for enhanced efficacy in inflammatory conditions  

NASA Astrophysics Data System (ADS)

In the present study, we have investigated the potential of a nanoemulsion (thermodynamically stable transparent dispersions of oil and water having a droplet size <200 nm) formulation for the topical delivery of COX-2 inhibitors using etoricoxib as a model drug. Various oil-in-water nanoemulsions were prepared by the spontaneous emulsification method. The nanoemulsion area was identified by constructing pseudo-ternary phase diagrams. The prepared nanoemulsions were subjected to thermodynamic stability testing. Those that passed these tests were characterized for viscosity, droplet size and differential scanning calorimetry. Topical permeation of etoricoxib through porcine abdominal skin was estimated using the Franz diffusion cell. The ex vivo skin permeation profile of optimized formulations was compared with that of etoricoxib conventional gel. A significant increase in permeability was observed in optimized nanoemulsion formulations consisting of 2 % w/w of etoricoxib, 20 % w/w of Triacetin, 38 % w/w of a surfactant mixture (Cremophor RH 40:Transcutol P), and 42 % w/w of water. The anti-inflammatory effects of this formulation on carrageenan-induced paw edema in rats showed a significant increase in the percent inhibition value (84.61 % with the nanoemulsion gel and 92.30 % with the nanoemulsion) as compared with the conventional gel (69.23 %) after 6 h when compared with etoricoxib conventional gel. These results suggest that nanoemulsions can serve as potential vehicles for improved transdermal delivery of anti-inflammatory agents such as etoricoxib.

Lala, R. R.; Awari, N. G.

2013-01-01

82

Synthesis and biological evaluation of 3,4-diphenyl-1,2,5-oxadiazole-2-oxides and 3,4-diphenyl-1,2,5-oxadiazoles as potential hybrid COX-2 inhibitor/nitric oxide donor agents.  

PubMed

A group of 3,4-diphenyl-1,2,5-oxadiazole-2-oxides (3,4-diphenylfuroxans) and the corresponding N-desoxy 3,4-diphenyl-1,2,5-oxadiazoles (3,4-diphenylfurazans) analogs, were synthesized for in vitro evaluation as hybrid cyclooxygenase (COX) inhibitor/nitric oxide donor agents. Reaction of 1-[4-(methylsulfonyl)phenyl]-2-phenylethene with an aqueous sodium nitrite solution in acetic acid afforded a mixture (3:1 ratio) of the inseparable 4-[4-(methylsulfonyl)phenyl]-3-phenyl-1,2,5-oxadiazole-2-oxide (13a) and 3-[4-(methylsulfonyl)phenyl]-4-phenyl-1,2,5-oxadiazole-2-oxide (13b) regioisomers. A group of related regioisomers possessing either a p-aminosulfonylphenyl (16) or a p-azidosulfonylphenyl (17), moiety were obtained by chlorosulfonation of the unsubstituted 3,4-diphenylfuroxan (10) and subsequent reaction with either ammonium hydroxide or sodium azide, respectively. The methanesulfonyl regioisomers 13a,b [COX-1 IC50=11.6 microM; COX-2 IC50=0.12 microM; COX-2 selectivity index (SI)=97] and aminosulfonyl regioisomers 16 (COX-1 IC50=9.8 microM; COX-2 IC50=0.78 microM; COX-2 SI=12), like the reference drug celecoxib (COX-1 IC50=33.1 microM; COX-2 IC50=0.07 microM; COX-2 SI=472), were potent in vitro COX-2 inhibitors with a good COX-2 selectivity index. Release of nitric oxide (NO) from the 3,4-diphenylfuroxan compounds (10, 13a,b, 16, 17) was thiol-dependent since the % NO released was higher upon incubation in the presence of l-cysteine (0.57-3.18%) compared to that in phosphate buffer solution at pH7.4 (0.06-0.15%). Molecular modeling (docking) studies show that the methanesulfonyl (MeSO2) COX-2 pharmacophore present in regioisomers 13a,b is positioned in the vicinity of the COX-2 secondary pocket. The in vitro NO release data, COX-1/COX-2 inhibition and COX-2 SI structure-activity relationships acquired, and molecular modeling docking studies suggest that the 1,2,5-oxadiazole-2-oxide (furoxan) ring possesses beneficial features that should be present in a suitable central ring template (bioisostere) pertinent to the design novel hybrid COX-2 inhibitor/nitric oxide donor agents with a low ulcerogenicity profile that may be free from adverse cardiovascular effects. PMID:15781386

Velázquez, Carlos; Rao, P N Praveen; McDonald, Robert; Knaus, Edward E

2005-04-15

83

The effects of a COX-2 inhibitor meloxicam on squamous cell carcinoma of the esophagus in vivo.  

PubMed

Our previous study showed that aspirin induced apoptosis of esophageal cancer cells in vitro by inhibiting the pathway of NF-kappaB downstream regulation of cyclooxygenase-2. The purpose of this study was to determine if similar changes occurred in vivo in the tumors of patients with SCC of the esophagus who were given a preferential COX-2 inhibitor, meloxicam. Fifty-three patients who had an esophagectomy for SCC were allocated randomly to either a Treatment group (n = 25) or a control group (n = 28). Patients in the Treatment group were given 7.5 mg/day of meloxicam, for between 10 and 14 days before surgery. Patients in the control group did not take any type of NSAID during this time interval. Samples of the tumor taken from the resected specimens were collected. Proliferation and apoptosis were measured by flow cytometry. The concentration of 6-keto-prostaglandin F(1)alpha in cancer tissue was determined by radio-immuno-assay. Expression of COX-2 mRNA was measured with RT-PCR and COX-2 protein levels with Western blot analysis. Nuclear NF-kappaB and cytoplasmic I kappaB protein levels were determined by electrophoretic mobility shift assay and Western blot, respectively. There were significantly more apoptotic cells in the tumors of patients who were using meloxicam. It also decreased the levels of COX-2 mRNA, COX-2 protein and nuclear NF-kappaB protein and increased the cytoplasmic I kappaB protein in the cancer. We conclude that meloxicam induces apoptosis in SCC of the esophagus in vivo by inhibiting the pathway of NF-kappaB downstream regulation of COX-2. PMID:18058818

Liu, Jun-Feng; Zhang, Shao-Wei; Jamieson, Glyn G; Zhu, Gui-Jun; Wu, Tie-Cheng; Zhu, Tie-Nian; Shan, Bao-En; Drew, Paul A

2008-04-01

84

Epidermal COX-2 induction following ultraviolet irradiation: suggested mechanism for the role of COX-2 inhibition in photoprotection.  

PubMed

The cyclooxygenase isoforms, COX-1 and COX-2, are involved in the biosynthesis of prostaglandin E2, a major prostaglandin involved in epidermal homeostasis and repair. Cancer originating in the epidermis can develop when keratinocyte proliferation and apoptosis become dysregulated, resulting in sustained epidermal hyperplasia. COX-2 inhibitors, which demonstrate significant in vivo selectivity relative to COX-1, suppress both ultraviolet-induced epidermal tumor development and progression, suggesting that prostaglandin regulation of keratinocyte biology is involved in the pathogenesis of epidermal neoplasia. In this study, we characterized the expression of COX-1 and COX-2, as well as keratinocyte proliferation, differentiation, and apoptosis, following acute ultraviolet irradiation in the hairless SKH-1 mouse. Following acute ultraviolet exposure, COX-2 expression was predominantly induced in the basal keratinocyte layer coincident with an increase in keratinocyte proliferation and apoptosis. The role of COX-2 was further evaluated using a selective COX-2 inhibitor, SC-791, as well as the traditional nonsteroidal COX inhibitor, indomethacin. Following acute ultraviolet irradiation, inhibition of COX-2 with either inhibitor decreased epidermal keratinocyte proliferation. Likewise, keratinocyte apoptosis was increased with COX-2 inhibition, particularly in the proliferating basal keratinocyte layer. There was also a modest inhibition of keratinocyte differentiation. These data suggest that COX-2 expression is probably necessary for keratinocyte survival and proliferation occurring after acute ultraviolet irradiation. We hypothesize that selective COX-2 inhibition, as described herein, may lead to enhanced removal of ultraviolet-damaged keratinocytes, thereby decreasing malignant transformation in the epidermis. PMID:14632205

Tripp, Catherine S; Blomme, Eric A G; Chinn, Kevin S; Hardy, Medora M; LaCelle, Peter; Pentland, Alice P

2003-10-01

85

The effect of a single dose of preemptive pregabalin administered with COX-2 inhibitor: a trial in total knee arthroplasty.  

PubMed

We sought to compare a group (Group L) (n=21) of patients that underwent total knee arthroplasty and received a single preoperative dose of pregabalin combined with a COX-2 inhibitor with a control group (Group C) (n=20) that only received a COX-2 inhibitor in terms of (1) acute postoperative pain intensity, (2) analgesic consumption, and (3) functional recovery. Mean cumulative fentanyl consumption during the first 48 hours was lower in Group L than in Group C (P<0.05). The pain scores at rest were lower in Group L at 6 and 12 hours after surgery (P<0.05). No significant intergroup difference was noted in functional recovery. The addition of pregabalin led to an additive reduction in early postoperative pain and analgesic consumption. PMID:24851793

Lee, Jin Kyu; Chung, Kyu-Sung; Choi, Choong Hyeok

2015-01-01

86

Hepatic Ischemia and Reperfusion Injury in the Absence of Myeloid Cell-Derived COX-2 in Mice  

PubMed Central

Cyclooxygenase-2 (COX-2) is a mediator of hepatic ischemia and reperfusion injury (IRI). While both global COX-2 deletion and pharmacologic COX-2 inhibition ameliorate liver IRI, the clinical use of COX-2 inhibitors has been linked to increased risks of heart attack and stroke. Therefore, a better understanding of the role of COX-2 in different cell types may lead to improved therapeutic strategies for hepatic IRI. Macrophages of myeloid origin are currently considered to be important sources of the COX-2 in damaged livers. Here, we used a Cox-2flox conditional knockout mouse (COX-2?M/?M) to examine the function of COX-2 expression in myeloid cells during liver IRI. COX-2?M/?M mice and their WT control littermates were subjected to partial liver ischemia followed by reperfusion. COX-2?M/?M macrophages did not express COX-2 upon lipopolysaccharide stimulation and COX-2?M/?M livers showed reduced levels of COX-2 protein post-IRI. Nevertheless, selective deletion of myeloid cell-derived COX-2 failed to ameliorate liver IRI; serum transaminases and histology were comparable in both COX-2?M/?M and WT mice. COX-2?M/?M livers, like WT livers, developed extensive necrosis, vascular congestion, leukocyte infiltration and matrix metalloproteinase-9 (MMP-9) expression post-reperfusion. In addition, myeloid COX-2 deletion led to a transient increase in IL-6 levels after hepatic reperfusion, when compared to controls. Administration of celecoxib, a selective COX-2 inhibitor, resulted in significantly improved liver function and histology in both COX-2?M/?M and WT mice post-reperfusion, providing evidence that COX-2-mediated liver IRI is caused by COX-2 derived from a source(s) other than myeloid cells. In conclusion, these results support the view that myeloid COX-2, including myeloid-macrophage COX-2, is not responsible for the hepatic IRI phenotype. PMID:24819536

Duarte, Sergio; Kato, Hiroyuki; Kuriyama, Naohisa; Suko, Kathryn; Ishikawa, Tomo-o; Busuttil, Ronald W.; Herschman, Harvey R.; Coito, Ana J.

2014-01-01

87

From COX-2 inhibitor nimesulide to potent anti-cancer agent: synthesis, in vitro, in vivo and pharmacokinetic evaluation  

PubMed Central

Cyclooxygenase-2 (COX-2) inhibitor nimesulide inhibits the proliferation of various types of cancer cells mainly via COX-2 independent mechanisms, which makes it a good lead compound for anti-cancer drug development. In the presented study, a series of new nimesulide analogs were synthesized based on the structure–function analysis generated previously. Some of them displayed very potent anti-cancer activity with IC50s around 100nM to 200nM to inhibit SKBR-3 breast cancer cell growth. CSUOH0901 (NSC751382) from the compound library also inhibits the growth of the 60 cancer cell lines used at National Cancer Institute Developmental therapeutics Program (NCIDTP) with IC50s around 100nM to 500nM. Intraperitoneal injection with a dosage of 5mg/kg/d of CSUOH0901 to nude mice suppresses HT29 colorectal xenograft growth. Pharmacokinetic studies demonstrate the good bioavailability of the compound. PMID:22119125

Chennamaneni, Snigdha; Yi, Xin; Liu, lili; Pink, John J.; Dowlati, Afshin; Xu, Yan; Zhou, Aimin; Su, Bin

2014-01-01

88

Recent Methodologies toward the Synthesis of Valdecoxib: A Potential 3,4-diarylisoxazolyl COX-2 Inhibitor  

PubMed Central

Non-steroidal anti-inflammatory drugs are widely used therapeutic agents in the treatment of inflammation, pain and fever. Cyclooxygenase catalyzes the initial step of biotransformation of arachidonic acid to prostanoids, and exist as three distinct isozymes; COX-I, COX-II and COX-III. Selective COX-II inhibitors are a class of potential anti-inflammatory, analgesic, and antipyretic drugs with reduced gastrointestinal (GI) side effects compared to nonselective inhibitors. 3,4-diarylisoxazole scaffold is recurrently found in a wide variety of NSAIDs, protein kinase inhibitors, hypertensive agents, and estrogen receptor (ER) modulators. In the present review, we document on the recent synthetic strategies of 3,4-diarylisoxazolyl scaffolds of valdecoxib and its relevant structural analogues. PMID:20724040

Dadiboyena, Sureshbabu; Nefzi, Adel

2011-01-01

89

Effect of COX-2 inhibitors and other non-steroidal inflammatory drugs on breast cancer risk: a meta-analysis.  

PubMed

Evidence on non-steroidal anti-inflammatory drugs (NSAID) use and breast cancer risk shows a slightly protective effect of these drugs, but previous studies lack randomized clinical trial results and present high heterogeneity in exposure measurement. This systematic review and meta-analysis widens the knowledge about NSAID use and breast cancer risk, updating the information from the last meta-analysis, focusing on evidence on specific effects of COX-2 inhibitors and differential expression patterns of hormonal receptors. A PubMed-database search was conducted to include all entries published with the keywords "BREAST CANCER NSAID ANTI-INFLAMMATORY" until 10/24/2013 providing original results from cohort studies, case-control studies, or randomized clinical trials with at least one reported relative risk (RR) or odds ratio (OR) on the association between any NSAID use and incidence of invasive breast cancer. This resulted in 49 publications, from which the information was retrieved about type of study, exposure characteristics, breast cancer characteristics, and breast cancer-NSAID association. Meta-analyses were performed separately for case-control and cohort studies and for different hormone-receptor status. NSAID use reduced invasive breast cancer risk by about 20 %. A similar effect was found for aspirin, acetaminophen, COX-2 inhibitors and, to a lesser extent, ibuprofen. The effect of aspirin was similar in preventing hormone-receptor-positive breast cancer. This meta-analysis suggests a slightly protective effect of NSAIDs-especially aspirin and COX-2 inhibitors- against breast cancer, which seems to be restricted to ER/PR+tumors. PMID:25589172

de Pedro, María; Baeza, Sara; Escudero, María-Teresa; Dierssen-Sotos, Trinidad; Gómez-Acebo, Inés; Pollán, Marina; Llorca, Javier

2015-01-01

90

ANTI-INFLAMMATORY EFFECTS OF SELECTIVE COX2 INHIBITORS  

Microsoft Academic Search

In this study, effects of rofecoxib, celecoxib, nimesulide on the acute phase of inflammation were studied in the carrageenan-induced paw edema model and their influence on the chronic phase of inflammation was evalu- ated in the cotton pellet granuloma tests. Additionally, effects of these drugs on capillary vascular permeability were examined in the hyaluronidase test and were compared with that

Halis Süleyman; Berna Demircan

91

Original article Potent, orally available, selective COX-2 inhibitors based  

E-print Network

. The lead compound demonstrated very good oral bioavailability in mice, slow metabolic degradation, modest distribution into the brain and a remarkable anti-inflammatory efficacy in carrageenan-induced mouse paw edema a potential for diverse therapeutic applications in inflammatory disease area. © 2014 Elsevier Masson SAS. All

Hammock, Bruce D.

92

Chiral 3,3'-(1,2-ethanediyl)-bis[2-(3,4-dimethoxyphenyl)-4-thiazolidinones] with anti-inflammatory activity. Part 11: evaluation of COX-2 selectivity and modelling.  

PubMed

Anti-inflammatory/analgesic 3,3'-(1,2-ethanediyl)-bis[2-(3,4-dimethoxyphenyl)-4-thiazolidinones] 1, obtained as racemic mixtures (a) and mesoforms (b), have two equivalent stereogenic centres (C-2 and C-2') and exist as RR, SS and RS isomers. The enantioseparation of 1a provided the single enantiomers that displayed different in vitro cyclooxygenase-1/cyclooxygenase-2 selectivity ratios. In particular the dextrorotatory compound is a highly selective COX-2 inhibitor and the levorotatory one is moderately selective. Instead, RS-meso isomer (1b) exhibited similar levels of inhibitory activity on both COX isozymes. The diastereo- and enantioselectivity has been explained by molecular modelling of RR, SS and RS compounds into COX-1 and COX-2 binding sites. Theoretical results indicated SS>RS>RR affinity order towards COX-2 isoenzyme, in agreement with in vitro and previous in vivo pharmacological results. PMID:12614885

Vigorita, M G; Ottanà, R; Monforte, F; Maccari, R; Monforte, M T; Trovato, A; Taviano, M F; Miceli, N; De Luca, G; Alcaro, S; Ortuso, F

2003-03-20

93

Guggulsterone, a Plant-Derived Inhibitor of NF-?B, Suppresses CDX2 and COX-2 Expression and Reduces the Viability of Esophageal Adenocarcinoma Cells.  

PubMed

Background/Aims: Induction by bile acid of caudal type homeobox 2 (CDX2) and cyclooxygenase-2 (COX-2) expression via nuclear factor-?B (NF-?B) activation is a critical event in the development of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). Guggulsterone (GS) is a plant sterol that inhibits NF-?B activity. Here, we evaluated whether GS has either or both chemopreventive or therapeutic effects against EAC. Methods: Two EAC cells lines were treated with deoxycholic acid (DCA) in the presence of GS or vehicle. The levels of transcription and translation of I?B?, CDX2, and COX-2 were determined. Prostaglandin E2 (PGE2) levels, cell viability, and cell cycle distribution were assessed as well. Results: GS inhibited DCA-induced I?B? phosphorylation. GS and the NF-?B inhibitor BAY11-7085 suppressed DCA-induced CDX2 and COX-2 expression in EAC cells. GS also suppressed basal transcription levels of CDX2 and COX-2 and reduced constitutive synthesis of COX-2 and PGE2. Further, GS reduced the viability of EAC cells, increased their numbers in the apoptotic sub-G1 fraction. Conclusion: GS suppressed DCA-induced and NF-?B-dependent activation of CDX2 and COX-2 expression. Further, GS also reduced the viability of EAC cells. GS may serve as candidate for preventing and treating EAC and BE. © 2014 S. Karger AG, Basel. PMID:25427631

Yamada, Takanori; Osawa, Satoshi; Ikuma, Mutsuhiro; Kajimura, Masayoshi; Sugimoto, Mitsushige; Furuta, Takahisa; Iwaizumi, Moriya; Sugimoto, Ken

2014-11-21

94

Acetaminophen (paracetamol) is a selective cyclooxygenase-2 inhibitor in man.  

PubMed

For more than three decades, acetaminophen (INN, paracetamol) has been claimed to be devoid of significant inhibition of peripheral prostanoids. Meanwhile, attempts to explain its action by inhibition of a central cyclooxygenase (COX)-3 have been rejected. The fact that acetaminophen acts functionally as a selective COX-2 inhibitor led us to investigate the hypothesis of whether it works via preferential COX-2 blockade. Ex vivo COX inhibition and pharmacokinetics of acetaminophen were assessed in 5 volunteers receiving single 1000 mg doses orally. Coagulation-induced thromboxane B(2) and lipopolysaccharide-induced prostaglandin E(2) were measured ex vivo and in vitro in human whole blood as indices of COX-1 and COX-2 activity. In vitro, acetaminophen elicited a 4.4-fold selectivity toward COX-2 inhibition (IC(50)=113.7 micromol/L for COX-1; IC(50)=25.8 micromol/L for COX-2). Following oral administration of the drug, maximal ex vivo inhibitions were 56% (COX-1) and 83% (COX-2). Acetaminophen plasma concentrations remained above the in vitro IC(50) for COX-2 for at least 5 h postadministration. Ex vivo IC(50) values (COX-1: 105.2 micromol/L; COX-2: 26.3 micromol/L) of acetaminophen compared favorably with its in vitro IC(50) values. In contrast to previous concepts, acetaminophen inhibited COX-2 by more than 80%, i.e., to a degree comparable to nonsteroidal antiinflammatory drugs (NSAIDs) and selective COX-2 inhibitors. However, a >95% COX-1 blockade relevant for suppression of platelet function was not achieved. Our data may explain acetaminophen's analgesic and antiinflammatory action as well as its superior overall gastrointestinal safety profile compared with NSAIDs. In view of its substantial COX-2 inhibition, recently defined cardiovascular warnings for use of COX-2 inhibitors should also be considered for acetaminophen. PMID:17884974

Hinz, Burkhard; Cheremina, Olga; Brune, Kay

2008-02-01

95

Restoration of E-cadherin expression by selective Cox-2 inhibition and the clinical relevance of the epithelial-to-mesenchymal transition in head and neck squamous cell carcinoma  

PubMed Central

Background The epithelial-to-mesenchymal transition (EMT) accompanied by the downregulation of E-cadherin has been thought to promote metastasis. Cyclooxygenase-2 (Cox-2) is presumed to contribute to cancer progression through its multifaceted function, and recently its inverse relationship with E-cadherin was suggested. The aim of the present study was to investigate whether selective Cox-2 inhibitors restore the expression of E-cadherin in head and neck squamous cell carcinoma (HNSCC) cells, and to examine the possible correlations of the expression levels of EMT-related molecules with clinicopathological factors in HNSCC. Methods We used quantitative real-time PCR to examine the effects of three selective Cox-2 inhibitors, i.e., celecoxib, NS-398, and SC-791 on the gene expressions of E-cadherin (CDH-1) and its transcriptional repressors (SIP1, Snail, Twist) in the human HNSCC cell lines HSC-2 and HSC-4. To evaluate the changes in E-cadherin expression on the cell surface, we used a flowcytometer and immunofluorescent staining in addition to Western blotting. We evaluated and statistically analyzed the clinicopathological factors and mRNA expressions of Cox-2, CDH-1 and its repressors in surgical specimens of 40 patients with tongue squamous cell carcinoma (TSCC). Results The selective Cox-2 inhibitors upregulated the E-cadherin expression on the cell surface of the HNSCC cells through the downregulation of its transcriptional repressors. The extent of this effect depended on the baseline expression levels of both E-cadherin and Cox-2 in each cell line. A univariate analysis showed that higher Cox-2 mRNA expression (p?=?0.037), lower CDH-1 mRNA expression (p?=?0.020), and advanced T-classification (p?=?0.036) were significantly correlated with lymph node metastasis in TSCC. A multivariate logistic regression revealed that lower CDH-1 mRNA expression was the independent risk factor affecting lymph node metastasis (p?=?0.041). Conclusions These findings suggest that the appropriately selective administration of certain Cox-2 inhibitors may have an anti-metastatic effect through suppression of the EMT by restoring E-cadherin expression. In addition, the downregulation of CDH-1 resulting from the EMT may be closely involved in lymph node metastasis in TSCC. PMID:24887090

2014-01-01

96

Interaction between cyclooxygenase (COX)-1- and COX-2-products modulates COX-2 expression in the late phase of acute inflammation.  

PubMed

Prostanoid production depends on the activity of two cyclooxygenase (COX) isoforms. It is appreciated that COX-1 plays a role in physiological processes, whereas COX-2 acts in pathological conditions. However their roles, particularly roles of COX-1, have not yet been fully established in inflammation. Here, we examined the effects of COX inhibitors, having differential isoform selectivity, on the late phase of rat carrageenin-induced pleurisy to elucidate the role of COX-2 expressed in the draining lymph nodes and found substantial contribution of COX-1-product(s). Protein and mRNA of COX-2 were detectable with Western blotting analysis and reverse-transcription polymerase chain reaction (RT-PCR) analysis in parathymic lymph nodes, peaking at 48 h after induction of pleurisy. Microsomal prostaglandin E synthase (mPGES)-1 was detectable by immunohistochemical analysis in cells with dendritic processes, a morphological characteristic similar to that of COX-2 expressing cells. Although aspirin, indomethacin and a COX-1 inhibitor, ketorolac, significantly decreased the volume of pleural exudate, they did not affect the levels of COX-2 and mPGES-1 in the lymph node 24 h after induction of pleurisy. In contrast, COX-2 inhibitors, nimesulide and NS-398, had no effect on the exudate volume, but they increased the number of COX-2- and mPGES-1-expressing cells and extension of their dendritic processes with significant increase in the COX-2 level, which were antagonised by ketorolac. These results suggest that COX-2-expressing cells may negatively self-regulate their functions by producing PGE2 via mPGES-1: migration into the draining lymph node and their differentiation. Moreover, COX-1- and COX-2-derived prostanoids may play differential or sometimes antagonistic roles in the late phase of acute inflammation. PMID:17258197

Nakano, Masashi; Denda, Naoyuki; Matsumoto, Misako; Kawamura, Michiko; Kawakubo, Yasuaki; Hatanaka, Ko; Hiramoto, Yoshisuke; Sato, Yu-ichi; Noshiro, Makoto; Harada, Yoshiteru

2007-03-22

97

Induction but not inhibition of COX-2 confers human lung cancer cell apoptosis by celecoxib  

PubMed Central

The antitumorigenic mechanism of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib is still a matter of debate. Among different structurally related COX-2 inhibitors, only celecoxib was found to cause apoptosis and cell death of human lung cancer cells (IC50 values of 19.96 µM [A549], 12.48 µM [H460], and 41.39 µM [H358]) that was paralleled by a time- and concentration-dependent upregulation of COX-2 and peroxisome proliferator-activated receptor ? (PPAR?) at mRNA and protein levels. Apoptotic death of celecoxib-treated cancer cells was suppressed by the PPAR? antagonist GW9662 and by siRNA targeting PPAR? and, surprisingly, also by the selective COX-2 inhibitor NS-398 and siRNA targeting COX-2. NS-398 (1 µM) was shown to suppress celecoxib-induced COX-2 activity. Among the COX-2-dependent prostaglandins (PG) induced upon celecoxib treatment, PGD2 and 15-deoxy-?12,14-PGJ2 were found to induce a cytosol-to-nucleus translocation of PPAR? as well as a PPAR?-dependent apoptosis. Celecoxib-elicited PPAR? translocation was inhibited by NS-398. Finally, a COX-2- and PPAR?-dependent cytotoxic action of celecoxib was proven for primary human lung tumor cells. Together, our data demonstrate a proapoptotic mechanism of celecoxib involving initial upregulation of COX-2 and PPAR? and a subsequent nuclear translocation of PPAR? by COX-2-dependent PGs. PMID:23943857

Ramer, Robert; Walther, Udo; Borchert, Philipp; Laufer, Stefan; Linnebacher, Michael; Hinz, Burkhard

2013-01-01

98

Comparative Study for Preventive Effects of Intra-Abdominal Adhesion Using Cyclo-Oxygenase-2 Enzyme (COX-2) Inhibitor, Low Molecular Weight Heparin (LMWH), and Synthetic Barrier  

PubMed Central

Purpose Postoperative adhesion is the most frequent complication of abdominal surgery. Therefore, we investigated the individual effects of synthetic barrier [hyaluronic acid/carboxymethylcellulose (HA/CMC)] and pharmacologic agents [low molecular weight heparin (LMWH) cyclo-oxygenase-2 inhibitor (COX-2 inhibitor)] using animal model of intra-abdominal adhesion. Materials and Methods The cecum was rubbed with sterile alcohol wet gauze until subserosal haemorrhage and punctate bleeding developed under the general anesthesia. Five animal groups were prepared using the film HA/CMC, gel HA/CMC, LMWH and COX-2 inhibitor. Results The grade of adhesion by modified Leach method for group I (control), II (film type HA/CMC), III (gel type HA/CMC), IV (LMWH) and V (COX-2 inhibitor) were 5.35±1.8, 6.15±1.3, 4.23±2.6, 5.05±0.7 and 5.50±0.9, respectively. Group III showed the least grade of adhesion and it is statistically significant in adhesion formation (p=0.028). The numbers of lymphocytes were significantly low in group III and group V compared to the control group (lymphocyte: p=0.004). The mast cell counts were generally low except for the control group (I: 1.05, II: 0.35, III: 0.38, IV: 0.20, V: 0.37), however, it was not statistically significant (p=0.066). Conclusion The gel barriers were shown to be partly efficient in inhibiting the formation of postoperative adhesions and might provide an option for abdominal surgery to reduce postoperative adhesions. The LMWH and COX-2 inhibitor had been known for their inhibitor effect of fibrin formation and anti-angiogenic/anti-fibroblastic activity, respectively. However, their preventive effects of adhesion and fibrosis were found to be obscure. PMID:24142656

2013-01-01

99

Design and synthesis of (Z)-1,2-diphenyl-1-(4-methanesulfonamidophenyl)alk-1-enes and (Z)-1-(4-azidophenyl)-1,2-diphenylalk-1-enes: novel inhibitors of cyclooxygenase-2 (COX-2) with anti-inflammatory and analgesic activity.  

PubMed

A group of novel (Z)-1,2-diphenyl-1-(4-methanesulfonamidophenyl)alk-1-enes was designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1/COX-2 enzyme inhibition studies identified (Z)-1,2-diphenyl-1-(4-methanesulfonamidophenyl)oct-1-ene (8d) as a highly potent (IC50=0.03 microM), and an extremely selective [COX-2 SI (selectivity index)>3,333], COX-2 inhibitor that showed good anti-inflammatory (AI) activity (ID50=2.8 mg/kg). A molecular modeling (docking) study showed that the p-MeSO2NH group present in (Z)-8d inserts deep inside the 2 degrees-pocket of the COX-2 binding site, it undergoes a hydrophobic interaction with Ala516 and Gly519, and one of the O-atoms of the MeSO2 group participates in a weak hydrogen bonding interaction with the NH2 of Arg513 (distance= 3.85 angstroms). Similar in vitro COX-1/COX-2 enzyme inhibition studies showed that the azido compound 1-(4-azidophenyl)-1,2-diphenyloct-1-ene (9c) is also a potent and selective COX-2 inhibitor (COX-2 IC50=0.11 microM: SI>909) that exhibits good AI activity (ID50=5.0 mg/kg). A docking experiment to determine the orientation of (Z)-9c within the COX-2 binding site showed that the linear p-N3 group inserts into the COX-2 2 degrees-pocket, where it undergoes an ion-ion (electrostatic) interaction with Arg513. Structure-activity data acquired indicate that an olefin having either a C-1 p-MeSO2NH-phenyl, or a p-N3-phenyl, substituent, that is, cis to a C-2 unsubstituted phenyl substituent, in conjunction with C-1 unsubstituted phenyl and C-2 alkyl substituents, provides a novel template to design acyclic olefinic COX-2 inhibitors. PMID:15598562

Uddin, Md Jashim; Praveen Rao, P N; Knaus, Edward E

2005-01-17

100

Identification of novel cyclooxygenase-2 selective inhibitors using pharmacophore models.  

PubMed

In the present study we have investigated whether pharmacophore models may account for the activity and selectivity of the known cyclooxygenase-2 (COX-2) selective inhibitors of the phenylsulfonyl tricyclic series, i.e., Celecoxib (1) and Rofecoxib (3), and whether transferring this structural information onto the frame of a nonsteroidal antiinflammatory drug (NSAID), known to tightly bind the enzyme active site, may be useful for designing novel COX-2 selective inhibitors. With this aim we have developed a pharmacophore based on the geometric disposition of chemical features in the most favorable conformation of the COX-2 selective inhibitors SC-558 (2; analogue of Celecoxib (1)) and Rofecoxib (3) and the more restrained compounds 4 (DFU) and 5. The pharmacophore model contains a sulfonyl S atom, an aromatic ring (ring plane A) with a fixed position of the normal to the plane, and an additional aromatic ring (ring plane B), both rings forming a dihedral angle of 290 degrees +/- 10 degrees. The final disposition of the pharmacophoric groups parallels the geometry of the ligand SC-558 (2) in the known crystal structure of the COX-2 complex. Moreover, the nonconserved residue 523 is known to be important for COX-2 selective inhibition; thus, the crystallographic information was used to position an excluded volume in the pharmacophore, accounting for the space limits imposed by this nonconserved residue. The geometry of the final five-feature pharmacophore was found to be consistent with the crystal structure of the nonselective NSAID indomethacin (6) in the COX-2 complex. This result was used to design indomethacin analogues 8 and 9 that exhibited consistent structure-activity relationships leading to the potent and selective COX-2 inhibitor 8a. Compound 8a (LM-1685) was selected as a promising candidate for further pharmacological evaluation. PMID:11906281

Palomer, Albert; Cabré, Francesc; Pascual, Jaume; Campos, Joaquín; Trujillo, María A; Entrena, Antonio; Gallo, Miguel A; García, Lluïsa; Mauleón, David; Espinosa, Antonio

2002-03-28

101

Synthesis of novel 2-mercaptobenzoxazole based 1,2,3-triazoles as inhibitors of proinflammatory cytokines and suppressors of COX-2 gene expression.  

PubMed

A library of novel bis-heterocycles containing 2-mercaptobenzoxazole based 1,2,3-triazoles has been synthesized using click chemistry approach. The compound 4 exhibited the most potent in vivo anti-inflammatory activity with 66.66% and 61.11% inhibition in comparison to celecoxib which showed 72.22% and 65.55% inhibition after 3 h and 5 h respectively. The compounds 4 and 9 suppressed the COX-2 gene expression by 0.94 and 0.79 fold and exhibited a selective index (COX-1/COX-2) of 64.79 and 66.47 respectively in comparison to celecoxib (SI value of 75.56). The in silico molecular docking studies showed the interactions of these molecules with Tyr-59, Tyr-119 and Gly-121. When compared with the standard drug celecoxib, compounds 4, 5, 7, 9 and 16 did not cause any gastric ulceration. PMID:24836072

Haider, Saqlain; Alam, Mohammad Sarwar; Hamid, Hinna; Shafi, Syed; Dhulap, Abhijeet; Hussain, Firasat; Alam, Perwez; Umar, Sadiq; Pasha, M A Q; Bano, Sameena; Nazreen, Syed; Ali, Yakub; Kharbanda, Chetna

2014-06-23

102

2-hydroxymethyl-4-[5-(4-methoxyphenyl)-3-trifluoromethyl-1H-1-pyrazolyl]-1-benzenesulfonamide (DRF-4367): an orally active COX-2 inhibitor identified through pharmacophoric modulation.  

PubMed

Analogs of 1,5-diarylpyrazoles with a novel pharmacophore at N1 were designed, synthesized and evaluated for the in-vitro cyclooxygenase (COX-1/COX-2) inhibitory activity. The variations at/around position-4 of the C-5 phenyl ring in conjunction with a CF3 and CHF2 groups at C-3 exhibited a high degree of potency and selectivity index (SI) for COX-2 inhibition. The in-vivo evaluation of these potent compounds with a few earlier ones indicated the 4-OMe-phenyl analog and the 4-NHMe-phenyl analog with a CF3, and the 4-OEt-phenyl analog with a CHF2 group at C-3 to possess superior potency than celecoxib. In addition to its impressive anti-inflammatory, antipyretic, analgesic and anti-arthritic properties, compound (DRF-4367) was found to possess an excellent pharmacokinetic profile, gastrointestinal (GI) safety in the long-term arthritis study and COX-2 potency in human whole blood assay. Thus, compound was selected as an orally active anti-inflammatory candidate for pre-clinical evaluation. PMID:15326524

Singh, Sunil Kumar; Vobbalareddy, Saibaba; Kalleda, Srinivasa Rao; Rajjak, Shaikh Abdul; Casturi, Seshagiri Rao; Datla, Srinivasa Raju; Mamidi, Rao N V S; Mullangi, Ramesh; Bhamidipati, Ravikanth; Ramanujam, Rajagopalan; Akella, Venkateswarlu; Yeleswarapu, Koteswar Rao

2004-09-01

103

Detection and quantification of cimicoxib, a novel COX-2 inhibitor, in canine plasma by HPLC with spectrofluorimetric detection: development and validation of a new methodology.  

PubMed

Cimicoxib (CX) is a selective COX-2 inhibitor recently launched on the veterinary market. No analytical method to detect CX in biological samples has been published to date. The chromatographic separation was performed with a Kinetex C18 analytical column (100 mm × 4.6 mm, 2.6 ?m particle size) at 25 °C. The mobile phase consisted of acetonitrile:buffer (10 mM AcONH4, pH 4.5) (35:65, v/v) at a flow rate of 1 mL/min. Excitation and emission wavelengths were 268 and 430 nm, respectively. The extraction used 500 ?L of plasma added to 100 ?L of IS (5 ?g/mL) and 100 ?L of 10% CF3COOH, extracted with 600 ?L of C2H2:Et2O (3:7, v/v). The organic phase was evaporated and reconstituted with 200 ?L of mobile phase. The CX recovery ranged from 74.5% to 82.6%. The limit of quantification was 25 ng mL(-1). The chromatographic runs were specific with no interfering peaks at the retention times of the analytes, as confirmed by HPLC-mass spectrometry experiments. The other validation parameters were in agreement with the international guidelines. The method was successfully tested on two dogs treated at two dose rates. It facilitated tracking of the plasma concentration for 24h and calculation of the main pharmacokinetic parameters. In conclusion, this method (extraction, separation and applied techniques) is simple, effective and specific. This is the first time that a method for the quantification of CX in plasma has been reported. This technique may have applications for further pharmacokinetic studies. PMID:23685411

Giorgi, Mario; Kim, Tae-Won; Saba, Alessandro; Rouini, Mohammad-Reza; Yun, Hyoin; Ryschanova, Raushan; Owen, Helen

2013-09-01

104

Short-term supplementation of COX2 inhibitor suppresses bone turnover in gonad-intact middle-aged male rats  

Microsoft Academic Search

There is an increasing body of evidence supporting the idea that nonsteroidal antiinflammatory drugs can effectively suppress\\u000a ovariectomy-induced bone loss in adult rats. The present study investigated the effects of supplementation of selective cyclooxygenase-2\\u000a inhibitor [5,5-dimethyl-3-(3 flurophenyl)-4-(4 methylsulphonal) phenyl-2 (6H) furanone, DFU] to diets on bone metabolism, bone mineral density (BMD), and histomorphometry in middle-aged male rats. Forty\\u000a 16-month-old male

Chwan-Li Shen; James K. Yeh; XingJia Wang

2006-01-01

105

Perioperative pain relief by a COX-2 inhibitor affects ileal repair and provides a model for anastomotic leakage in the intestine.  

PubMed

The authors examined the potential of the cyclooxygenase 2 (COX-2) inhibitor carprofen to reproducibly induce anastomotic leakage. In experiment 1, an anastomosis was constructed in both ileum and colon of 20 rats, and they were given carprofen (5 mg/kg subcutaneously every 24 hours) or buprenorphine (0.02 mg/kg subcutaneously every 12 hours). In another 20 rats an anastomosis was constructed in either ileum or colon, and all received carprofen (experiment 2). Animals were sacrificed after 3 days. In experiment 1, the ileal dehiscence rate was 60% in the carprofen group and 0% in the buprenorphine group (P = .0108). Colonic anastomoses in both groups remained patent. In experiment 2, the anastomotic leakage rate was 80% in ileum and 0% in colon. Thus, COX-2 inhibitors can severely interfere with intestinal healing, particularly in the ileum. Perioperative administration of carprofen yields a unique model for anastomotic leakage, which allows translational research on the effectiveness of perisuture line reinforcement. PMID:22532618

van der Vijver, R J; van Laarhoven, C J H M; de Man, B M; Lomme, R M L M; Hendriks, T

2013-04-01

106

The impact of the cox-2 inhibitor issue on perceptions of the pharmaceutical industry: content analysis and communication implications.  

PubMed

The field of risk communication has its roots in the environmental, chemical, space, and nuclear arenas. As a number of these sectors have now vastly improved their communication strategies, attention is being placed on sectors that have been more problematic as of late. Examples of such sectors, include the food industries and the pharmaceutical/health sector. This article focuses on how large, multinational pharmaceutical companies can better communicate risks by analysis of one specific case, namely, that of the Cox-2 controversy.(1) For purposes of this article, risk communication is best described as "the flow of information and risk evaluations back and forth between academic experts, regulatory practitioners, interest groups and the general public," and "big pharma" refers to the more traditional R & D-based, innovative pharmaceutical companies. PMID:17710597

Lofstedt, Ragnar E

2007-01-01

107

Differential salutary effects of nonselective and selective COX2 inhibitors in postoperative ileus in rats 1 1 Results were presented in part at XIVth International Congress of the Polish Pharmacological Society, Brain-Gut Axis in Gastrointestinal Protection and Damage Symposium, Cracow, Poland (selected for oral presentation), September 2001, 3rd EPHAR Congress, Lyon, France (Poster Award Diploma), July 2001  

Microsoft Academic Search

Background. Postoperative ileus (PI) is a common surgical complication, the treatment of which consists of supportive measures.Aim. The effects of several cyclooxygenase (COX) inhibitors and their interaction with l-arginine\\/nitric oxide synthase (NOS) pathway were tested in a rat PI model.Methods. Intestinal transit was measured as Evans blue migration after skin incision, laparotomy, or laparotomy followed by evisceration and gut handling.Results.

Roman P. Korolkiewicz; Marek Ujda; Jaros?aw D; Jaros?aw Ruczy?ski; Piotr Rekowski; Jacek Petrusewicz

2003-01-01

108

Design, synthesis and biological evaluation of new 5,5-diarylhydantoin derivatives as selective cyclooxygenase-2 inhibitors.  

PubMed

A new group of 5,5-diarylhydantoin derivatives bearing a methylsulfonyl COX-2 pharmacophore at the para position of the C-5 phenyl ring were designed and synthesized as selective COX-2 inhibitors. In vitro COX-1/COX-2 inhibition structure-activity relationships identified 5-[4-(methylsulfonyl)phenyl]-5-phenyl-hydantoin (4) as a highly potent and selective COX-2 inhibitor (COX-2 IC(50) = 0.077 ?M; selectivity index > 1298). It was more selective than the reference drug celecoxib (COX-2 IC(50) = 0.060 ?M; selectivity index = 405). A molecular modeling study where 4 was docked in the binding site of COX-2 indicated that the p-MeSO(2) COX-2 pharmacophore group on the C-5 phenyl ring is oriented in the vicinity of the COX-2 secondary pocket. The results of this study showed that the type of substituent on the N-3 hydantoin ring substituent is important for COX-2 inhibitory activity. PMID:21886896

Zarghi, Afshin; Javid, Farin Sattary; Ghodsi, Razieh; Dadrass, Orkideh G; Daraei, Bahram; Hedayati, Mehdi

2011-09-01

109

Resveratrol analogues as selective cyclooxygenase-2 inhibitors: synthesis and structure-activity relationship.  

PubMed

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is found in grapes and various medical plants. Among cytotoxic, antifungal, antibacterial cardioprotective activity resveratrol also demonstrates non-selective cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibition. In order to find more selective COX-2 inhibitors a series of methoxylated and hydroxylated resveratrol derivatives were synthesized and evaluated for their ability to inhibit both enzymes using in vitro inhibition assays for COX-1 and COX-2 by measuring PGE(2) production. Hydroxylated but not methoxylated resveratrol derivatives showed a high rate of inhibition. The most potent resveratrol compounds were 3,3',4',5-tetra-trans-hydroxystilbene (COX-1: IC(50)=4.713, COX-2: IC(50)=0.0113 microM, selectivity index=417.08) and 3,3',4,4',5,5'-hexa-hydroxy-trans-stilbene (COX-1: IC(50)=0.748, COX-2: IC(50)=0.00104 microM, selectivity index=719.23). Their selectivity index was in part higher than celecoxib, a selective COX-2 inhibitor already established on the market (COX-1: IC(50)=19.026, COX-2: IC(50)=0.03482 microM, selectivity index=546.41). Effect of structural parameters on COX-2 inhibition was evaluated by quantitative structure-activity relationship (QSAR) analysis and a high correlation was found with the topological surface area TPSA (r=0.93). Docking studies on both COX-1 and COX-2 protein structures also revealed that hydroxylated but not methoxylated resveratrol analogues are able to bind to the previously identified binding sites of the enzymes. Hydroxylated resveratrol analogues therefore represent a novel class of highly selective COX-2 inhibitors and promising candidates for in vivo studies. PMID:15465334

Murias, Marek; Handler, Norbert; Erker, Thomas; Pleban, Karin; Ecker, Gerhard; Saiko, Philipp; Szekeres, Thomas; Jäger, Walter

2004-11-01

110

Synergistic Effect of COX-2 Inhibitor on Paclitaxel-Induced Apoptosis in the Human Ovarian Cancer Cell Line OVCAR-3  

PubMed Central

Purpose Celecoxib, a highly selective cyclooxygenase-2 inhibitor, regulates apoptosis of several types of human cancer cells. The purpose of this study was to investigate whether celecoxib in combination with paclitaxel modulates apoptosis of ovarian cancer cells, and to identify the signal pathway by which celecoxib mediates apoptosis. Materials and Methods OVCAR-3 cells were exposed to paclitaxel (20 µM) in the absence or presence of celecoxib (10 µM). Cell viability was evaluated using a Cell Counting Kit-8 assay. Apoptosis was evaluated using Annexin-V/7-aminoactinomycin D staining and a cellular DNA fragmentation enzyme-linked immunosorbent assay. Caspase-3, -9, and cleavage of poly ADP-ribose polymerase (PARP) were determined by western blotting. Expression of nuclear factor-?B (NF-?B) and vascular endothelial growth factor (VEGF) and Akt activation were assessed using reverse transcriptase-polymerase chain reaction and western blotting. Results Celecoxib enhanced paclitaxel-induced growth inhibition of OVCAR-3 cells. Celecoxib significantly increased paclitaxel-induced apoptosis of OVCAR-3 cells. Pretreatment with celecoxib also increased activation of caspase-9, -3 and cleaved PARP following paclitaxel-treatment. Exposure of OVCAR-3 cells to celecoxib in combination with paclitaxel resulted in downregulation of NF-?B activation and VEGF expression. Furthermore, combining celecoxib and paclitaxel inhibited phosphorylation of Akt. Conclusion OVCAR-3 cells were sensitized to paclitaxel-induced apoptosis by celecoxib through downregulation of NF-?B and Akt activation, suggesting that celecoxib may work synergistically with paclitaxel to inhibit different targets and ultimately produce anticancer effects. Combining celecoxib with paclitaxel may prove beneficial in the clinical treatment of ovarian cancer. PMID:24520227

Kim, Hee Jung; Yim, Ga Won; Nam, Eun Ji

2014-01-01

111

Increased COX2 in the trigeminal nucleus caudalis is involved in orofacial pain induced by experimental tooth movement.  

PubMed

Pain is among the major problems during orthodontic treatment. Recent studies have shown that central Cyclooxygenase2 (COX2) pathway was involved in several pain models. The present study investigated whether inducible COX2 within the trigeminal nucleus caudalis (Vc) contributed to experimental tooth movement pain in freely moving rats. Elastic rubber bands were inserted between the first and second maxillary molars bilaterally to establish tooth movement model. The directed mouth wiping behavior was used to evaluate the pain during tooth movement. COX2 distribution in Vc was studied by immunohistochemistry and the changes of COX2 expression were detected by Western blot at different time point after rubber band insertion. Our results showed that tooth movement significantly increased COX2 expression in Vc and the time spent on mouth wiping, reaching a maximum at 1 day and then decreasing gradually. Furthermore, the rhythm change of COX2 expression in Vc and the mouth wiping behavior were much correlative with each other. All of the COX2-immunoreactive structures in Vc exhibited NeuN-immunopositive staining and most of these COX2-immunoreactive neurons were Fos-immunopositive. Importantly, the mouth wiping behavior could be attenuated by intracisternal injection of NS-398 (a selective COX2 inhibitor) but not by periodontal administration of NS-398. All these results suggested that increased COX2 in Vc was involved in tooth movement pain and thus may be a central target for orthodontic pain treatment. PMID:20091889

Gao, Yuan; Duan, Yin-Zhong

2010-03-01

112

Resveratrol analogues as selective cyclooxygenase-2 inhibitors: synthesis and structure–activity relationship  

Microsoft Academic Search

Resveratrol (3,5,4?-trihydroxy-trans-stilbene) is found in grapes and various medical plants. Among cytotoxic, antifungal, antibacterial cardioprotective activity resveratrol also demonstrates non-selective cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibition. In order to find more selective COX-2 inhibitors a series of methoxylated and hydroxylated resveratrol derivatives were synthesized and evaluated for their ability to inhibit both enzymes using in vitro inhibition assays for COX-1

Marek Murias; Norbert Handler; Thomas Erker; Karin Pleban; Gerhard Ecker; Philipp Saiko; Thomas Szekeres; Walter Jäger

2004-01-01

113

Design, synthesis and biological evaluation of 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives as selective cyclooxygenase-2 inhibitors.  

PubMed

A group of regioisomeric 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives possessing a COX-2 SO2Me pharmacophore at the para position of the C-2 or C-4 phenyl ring, in conjunction with a C-4 or C-2 phenyl (4-H) or substituted-phenyl ring (4-F,4-Cl,4-Br,4-OMe,4-Me, 4-NO2), were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. These target 5-oxo-1,4,5,6,7,8 hexahydroquinolines were synthesized via a Hansch condensation reaction. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 7,8-dihydro- 7,7-dimethyl-2-(4-methoxyphenyl)-4-(4-(methylsulfonyl)phenyl)quinolin-5(1H,4H,6H)- one (9c) as a potent COX-2 inhibitor (IC50 = 0.17 M) with a high COX-2 selectivity index (S.I. = 97.6) comparable to the reference drug celecoxib (COX-2 IC50 = 0.05 mM; COX-2 S.I= 405). A molecular modeling study where 9c was docked in active site of COX-2 showed that the p-SO2Me substituent on the C-2 phenyl ring is inserted into the secondary COX-2 binding site. The structure activity data acquired indicate that the position of the COX-2 SO2Me pharmacophore and type of substituent are important for COX-2 inhibitory activity. PMID:24711830

Zarghi, Afshin; Sabakhi, Iman; Topuzyan, Vigen; Hajimahdi, Zahra; Daraie, Bahram

2014-01-01

114

Design, Synthesis and Biological Evaluation of 5-Oxo-1,4,5,6,7,8 Hexahydroquinoline Derivatives as Selective Cyclooxygenase-2 Inhibitors  

PubMed Central

A group of regioisomeric 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives possessing a COX-2 SO2Me pharmacophore at the para position of the C-2 or C-4 phenyl ring, in conjunction with a C-4 or C-2 phenyl (4-H) or substituted-phenyl ring (4-F,4-Cl,4-Br,4-OMe,4-Me, 4-NO2), were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. These target 5-oxo-1,4,5,6,7,8 hexahydroquinolines were synthesized via a Hansch condensation reaction. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 7,8-dihydro- 7,7-dimethyl-2-(4-methoxyphenyl)-4-(4-(methylsulfonyl)phenyl)quinolin-5(1H,4H,6H)- one (9c) as a potent COX-2 inhibitor (IC50 = 0.17 M) with a high COX-2 selectivity index (S.I. = 97.6) comparable to the reference drug celecoxib (COX-2 IC50 = 0.05 mM; COX-2 S.I= 405). A molecular modeling study where 9c was docked in active site of COX-2 showed that the p-SO2Me substituent on the C-2 phenyl ring is inserted into the secondary COX-2 binding site. The structure activity data acquired indicate that the position of the COX-2 SO2Me pharmacophore and type of substituent are important for COX-2 inhibitory activity. PMID:24711830

Zarghi, Afshin; Sabakhi, Iman; Topuzyan, Vigen; Hajimahdi, Zahra; Daraie, Bahram

2014-01-01

115

Effect of nonsteroidal anti-inflammatory drugs with varying extent of COX-2-COX-1 selectivity on urinary sodium and potassium excretion in the rat.  

PubMed

Nonsteroidal anti-inflammatory drugs (NSAIDs) have different selectivity to inhibit cyclooxygenase-1 (COX-1) and COX-2. Treatment with NSAIDs has been associated with kidney side effects. We compared the effect of a selected group of NSAIDs with different COX-2--COX-1 selectivities on urinary sodium and potassium excretion in rats. Each treatment with rofecoxib, celecoxib, meloxicam, diclofenac, and flurbiprofen (30, 120, 9, 30, and 125 mg/kg, respectively) and placebo was administered orally once daily for 4 days. Urine was collected 0-8 h after each dose. Urinary sodium and potassium excretion and urine flow rate were compared with placebo. As compared with placebo, rofecoxib, celecoxib, diclofenac, and flurbiprofen significantly reduced excretion rate of sodium (rofecoxib, 0.28 +/- 0.02 vs. 0.41 +/- 0.03; celecoxib, 0.23 +/- 0.03 vs. 0.48 +/- 0.04; diclofenac, 0.09 +/- 0.02 vs. 0.46 +/- 0.03; and flurbiprofen, 0.11 +/- 0.02 vs. 0.47 +/- 0.02 micromol/(min x 100 g)) and potassium (rofecoxib, 0.55 +/- 0.04 vs. 0.68 +/- 0.04; celecoxib, 0.50 +/- 0.06 vs. 0.72 +/- 0.06; diclofenac, 0.26 +/- 0.05 vs. 0.67 +/- 0.04; and flurbiprofen, 0.35 +/- 0.05 vs. 0.62 +/- 0.03 micromol/ (min x 100 g)). Rofecoxib and flurbiprofen significantly reduced urine flow rate. Meloxicam had no significant effect on either sodium and potassium excretion or on the urine flow rate. At the examined dosage level, no relationship was found between reported COX-2--COX-1 selectivity and urinary electrolytes excretion. PMID:15759054

Harirforoosh, Sam; Jamali, Fakhreddin

2005-01-01

116

Viscum album-Mediated COX-2 Inhibition Implicates Destabilization of COX-2 mRNA  

PubMed Central

Extensive use of Viscum album (VA) preparations in the complementary therapy of cancer and in several other human pathologies has led to an increasing number of cellular and molecular approaches to explore the mechanisms of action of VA. We have recently demonstrated that, VA preparations exert a potent anti-inflammatory effect by selectively down-regulating the COX-2-mediated cytokine-induced secretion of prostaglandin E2 (PGE2), one of the important molecular signatures of inflammatory reactions. In this study, we observed a significant down-regulation of COX-2 protein expression in VA-treated A549 cells however COX-2 mRNA levels were unaltered. Therefore, we hypothesized that VA induces destabilisation of COX-2 mRNA, thereby depleting the available functional COX-2 mRNA for the protein synthesis and for the subsequent secretion of PGE2. To address this question, we analyzed the molecular degradation of COX-2 protein and its corresponding mRNA in A549 cell line. Using cyclohexamide pulse chase experiment, we demonstrate that, COX-2 protein degradation is not affected by the treatment with VA whereas experiments on transcriptional blockade with actinomycin D, revealed a marked reduction in the half life of COX-2 mRNA due to its rapid degradation in the cells treated with VA compared to that in IL-1?-stimulated cells. These results thus demonstrate that VA-mediated inhibition of PGE2 implicates destabilization of COX-2 mRNA. PMID:25664986

Saha, Chaitrali; Hegde, Pushpa; Friboulet, Alain; Bayry, Jagadeesh; Kaveri, Srinivas V.

2015-01-01

117

Co-administration of acetyl-11-keto-beta-boswellic acid, a specific 5-lipoxygenase inhibitor, potentiates the protective effect of COX-2 inhibitors in kainic acid-induced neurotoxicity in mice.  

PubMed

Cyclooxygenase (COX) and lipoxygenase (LOX) are responsible for the metabolism of arachidonic acid into inflammatory metabolites, prostaglandins and leukotrienes, respectively. The upregulation of these enzymes in the central nervous system has been demonstrated to be responsible for the increased neuronal vulnerability to degeneration. Kainic acid, a glutamate receptor agonist and responsible for neuronal excitotoxicity and oxidative damage via different mechanisms, is capable of stimulating mRNA of both COX-2 and 5-LOX in the brain. The present study was designed to study the effects of COX inhibitors (indomethacin, nimesulide, rofecoxib) and a 5-LOX inhibitor (acetyl-11-keto-beta-boswellic acid; AKBA) and the combination of these inhibitors (dual inhibition) on kainic acid induced excitotoxicity and oxidative and nitrosative damage in mice. The results from the present study indicated that AKBA, indomethacin, and nimesulide per se did not produce any change in the behavioural parameters after kainic acid administration; however, rofecoxib per seproduced a significant increase in the latency of clonic (seizure-like) movement and a decrease in mortality rate as compared with kainic acid treated animals. In combination studies AKBA, rofecoxib, and nimesulide produced a more pronounced effect than either of these drugs alone. Further, the effect of AKBA combined with rofecoxib was significantly more marked when compared with AKBA combined with nimesulide. Besides this, identical results were found for the effect of these agents and their combination against oxidative damage induced by kainic acid. These findings indicate the potential role of COX-2 inhibitors and also their combination with the 5-LOX inhibitor in kainic acid induced excitotoxicity and oxidative damage by virtue of their antioxidant effect and suggest the need for the development of dual inhibitors for the treatment of neuronal excitotoxicity. PMID:17139192

Bishnoi, Mahendra; Patil, C S; Kumar, Anil; Kulkarni, Shrinivas K

2007-01-01

118

COX2 in CNS neural cells mediates mechanical inflammatory pain hypersensitivity in mice  

PubMed Central

A cardinal feature of peripheral inflammation is pain. The most common way of managing inflammatory pain is to use nonsteroidal antiinflammatory agents (NSAIDs) that reduce prostanoid production, for example, selective inhibitors of COX2. Prostaglandins produced after induction of COX2 in immune cells in inflamed tissue contribute both to the inflammation itself and to pain hypersensitivity, acting on peripheral terminals of nociceptors. COX2 is also induced after peripheral inflammation in neurons in the CNS, where it aids in developing a central component of inflammatory pain hypersensitivity by increasing neuronal excitation and reducing inhibition. We engineered mice with conditional deletion of Cox2 in neurons and glial cells to determine the relative contribution of peripheral and central COX2 to inflammatory pain hypersensitivity. In these mice, basal nociceptive pain was unchanged, as was the extent of peripheral inflammation, inflammatory thermal pain hypersensitivity, and fever induced by lipopolysaccharide. By contrast, peripheral inflammation–induced COX2 expression in the spinal cord was reduced, and mechanical hypersensitivity after both peripheral soft tissue and periarticular inflammation was abolished. Mechanical pain is a major symptom of most inflammatory conditions, such as postoperative pain and arthritis, and induction of COX2 in neural cells in the CNS seems to contribute to this. PMID:19127021

Vardeh, Daniel; Wang, Dairong; Costigan, Michael; Lazarus, Michael; Saper, Clifford B.; Woolf, Clifford J.; FitzGerald, Garret A.; Samad, Tarek A.

2009-01-01

119

Cox-2 inhibitory effects of naturally occurring and modified fatty acids.  

PubMed

In the search for new cyclooxygenase-2 (COX-2) selective inhibitors, the inhibitory effects of naturally occurring fatty acids and some of their structural derivatives on COX-2-catalyzed prostaglandin biosynthesis were investigated. Among these fatty acids, linoleic acid (LA), alpha-linolenic acid (alpha-LNA), myristic acid, and palmitic acid were isolated from a CH(2)Cl(2) extract of the plant Plantago major by bioassay-guided fractionation. Inhibitory effects of other natural, structurally related fatty acids were also investigated: stearic acid, oleic acid, pentadecanoic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Further, the inhibitory effects of these compounds on COX-2- and COX-1-catalyzed prostaglandin biosynthesis was compared with the inhibition of some synthesized analogues of EPA and DHA with ether or thioether functions. The most potent COX-2-catalyzed prostaglandin biosynthesis inhibitor was all-(Z)-5-thia-8,11,14,17-eicosatetraenoic acid (2), followed by EPA, DHA, alpha-LNA, LA, (7E,11Z,14Z,17Z)-5-thiaeicosa-7,11,14,17-tetraenoic acid, all-(Z)-3-thia-6,9,12,15-octadecatetraenoic acid, and (5E,9Z,12Z,15Z,18Z)-3-oxaheneicosa-5,9,12,15,18-pentaenoic acid, with IC(50) values ranging from 3.9 to180 microM. The modified compound 2 and alpha-LNA were most selective toward COX-2, with COX-2/COX-1 ratios of 0.2 and 0.1, respectively. This study shows that several of the natural fatty acids as well as all of the semisynthetic thioether-containing fatty acids inhibited COX-2-catalyzed prostaglandin biosynthesis, where alpha-LNA and compound 2 showed selectivity toward COX-2. PMID:11421736

Ringbom, T; Huss, U; Stenholm, A; Flock, S; Skattebøl, L; Perera, P; Bohlin, L

2001-06-01

120

Prognostic significance of cyclooxygenase-2 (COX-2) and expression of cell cycle inhibitors p21 and p27 in human pleural malignant mesothelioma  

PubMed Central

Background: A study was undertaken to analyse the potential prognostic value of the immunohistochemical expression of cyclooxygenase-2 (COX-2) and p27 in 29 malignant mesotheliomas already screened for the expression of p21 and p53. Methods: Immunohistochemistry was used to determine the expression of COX-2 and p27. The correlation with survival of these factors and of p21 and p53 expression was assessed by univariate and multivariate analyses. Results: A positive statistically significant correlation was found between p27 and p21 expression (p<0.0001), but there was a negative correlation between COX-2 expression and both p27 (p = 0.001) and p21 (p<0.0001). No statistically significant correlation was recorded between p53 and all the other immunohistochemical parameters. Univariate analysis showed that overall survival was strongly influenced by p21, p27, and COX-2 expression, but multivariate Cox regression analysis showed that the only immunohistochemical parameter to influence overall survival of patients with mesothelioma was COX-2. Conclusions: These findings suggest that COX-2 expression may be a useful prognostic parameter for mesothelioma. PMID:15115874

Baldi, A; Santini, D; Vasaturo, F; Santini, M; Vicidomini, G; Di, M; Esposito, V; Groeger, A; Liuzzi, G; Vincenzi, B; Tonini, G; Piccoli, M; Baldi, F; Scarpa, S

2004-01-01

121

Cardiovascular Thromboembolic Adverse Effects Associated with Cyclooxygenase2 Selective Inhibitors and Nonselective Antiinflammatory Drugs  

Microsoft Academic Search

BACKGROUND: Concerns of increased cardiovascular (CV) thromboembolic adverse effects from nonsteroidal antiinflammatory drugs (NSAIDs, both nonselective (NS)-NSAIDs and cyclooxygenase (COX)-2 selective inhibitors) have prevented their use despite numerous benefits. METHODS: In this descriptive review, we critically examine the randomized, active- and placebo-controlled studies, observational trials, and meta-analyses evaluating the CV adverse effects associated with long-term and short-term use of COX-2

Girish P. Joshi; Ralph Gertler; Ruth Fricker

2007-01-01

122

The novel anti-inflammatory agent VA694, endowed with both NO-releasing and COX2-selective inhibiting properties, exhibits NO-mediated positive effects on blood pressure, coronary flow and endothelium in an experimental model of hypertension and endothelial dysfunction.  

PubMed

Selective cyclooxygenase 2 (COX2) inhibitors (COXIBs) are effective anti-inflammatory and analgesic drugs with improved gastrointestinal (GI) safety compared to nonselective nonsteroidal anti-inflammatory drugs known as traditional (tNSAIDs). However, their use is associated with a cardiovascular (CV) hazard (i.e. increased incidence of thrombotic events and hypertension) due to the inhibition of COX2-dependent vascular prostacyclin. Aiming to design COX2-selective inhibitors with improved CV safety, new NO-releasing COXIBs (NO-COXIBs) have been developed. In these hybrid drugs, the NO-mediated CV effects are expected to compensate for the COXIB-mediated inhibition of prostacyclin. This study evaluates the potential CV beneficial effects of VA694, a promising NO-COXIB, the anti-inflammatory effects of which have been previously characterized in several in vitro and in vivo experimental models. When incubated in hepatic homogenate, VA694 acted as a slow NO-donor. Moreover, it caused NO-mediated relaxant effects in the vascular smooth muscle. The chronic oral administration of VA694 to young spontaneously hypertensive rats (SHRs) significantly slowed down the age-related development of hypertension and was associated with increased plasma levels of nitrates, stable end-metabolites of NO. Furthermore, a significant improvement of coronary flow and a significant reduction of endothelial dysfunction were observed in SHRs submitted to chronic administration of VA694. In conclusion, VA694 is a promising COX2-inhibiting hybrid drug, showing NO releasing properties which may mitigate the CV deleterious effects associated with the COX2-inhibition. PMID:24083950

Martelli, A; Testai, L; Anzini, M; Cappelli, A; Di Capua, A; Biava, M; Poce, G; Consalvi, S; Giordani, A; Caselli, G; Rovati, L; Ghelardini, C; Patrignani, P; Sautebin, L; Breschi, M C; Calderone, V

2013-12-01

123

Prevention of colorectal cancer through the use of COX2 selective inhibitors  

Microsoft Academic Search

Colorectal cancer is a major cause of morbidity and mortality accounting for an estimated 550,000 deaths annually worldwide. Colonic neoplasia develops in a stepwise fashion progressing from normal mucosa to adenomatous polyps to carcinoma, a process that takes years, thereby providing a prime opportunity for intervention. Although early detection by fecal occult blood testing and sigmoidoscopy can decrease the risk

Richard M. Peek

2004-01-01

124

Evaluation of Selective COX2 Inhibitors for the Treatment of Alzheimer's Disease  

Microsoft Academic Search

Alzheimer's disease (AD) is a worldwide problem that affects 5 million people in the United States alone. Until the approval of tacrine in the mid-1990s, there was no effective therapy for the cognitive symptoms of AD. Although cholinergic therapy provides modest but significant symptomatic relief, the development of effective disease-modifying therapy is essential. It has been demonstrated that a number

Paul S Aisen

2002-01-01

125

Synthesis, biological evaluation, molecular docking and theoretical evaluation of ADMET properties of nepodin and chrysophanol derivatives as potential cyclooxygenase (COX-1, COX-2) inhibitors.  

PubMed

Nepodin and chrysophanol, isolated from Rumex nepalensis roots, showed significant cyclooxygenase (COX) inhibitory activity. To further optimize these lead molecules and study structure activity relationship (SAR), eighteen derivatives of nepodin and nine derivatives of chrysophanol were synthesized and evaluated for COX-1 and COX-2 inhibitory potential. Among the synthesized compounds, four nepodin (1f, 1g, 1h and 1i) and three chrysophanol (2e, 2f and 2h) derivatives displayed more pronounced COX-2 inhibition than their respective lead molecule. Further, compounds 1f, 1g, 2e and 2h exhibited better anti-inflammatory activity than ibuprofen in carrageenan-induced rat paw edema assay. Taking into account the in vitro and in vivo results, molecular docking and in silico prediction of ADMET properties of compounds were carried out respectively. PMID:24763362

Grover, Jagdeep; Kumar, Vivek; Singh, Vikram; Bairwa, Khemraj; Sobhia, M Elizabeth; Jachak, Sanjay M

2014-06-10

126

IL1{beta}-mediated Stromal COX-2 signaling mediates proliferation and invasiveness of colonic epithelial cancer cells  

SciTech Connect

COX-2 is a major inflammatory mediator implicated in colorectal inflammation and cancer. However, the exact origin and role of COX-2 on colorectal inflammation and carcinogenesis are still not well defined. Recently, we reported that COX-2 and iNOS signalings interact in colonic CCD18Co fibroblasts. In this article, we investigated whether activation of COX-2 signaling by IL1{beta} in primary colonic fibroblasts obtained from normal and cancer patients play a critical role in regulation of proliferation and invasiveness of human colonic epithelial cancer cells. Our results demonstrated that COX-2 level was significantly higher in cancer associated fibroblasts than that in normal fibroblasts with or without stimulation of IL-1{beta}, a powerful stimulator of COX-2. Using in vitro assays for estimating proliferative and invasive potential, we discovered that the proliferation and invasiveness of the epithelial cancer cells were much greater when the cells were co-cultured with cancer associated fibroblasts than with normal fibroblasts, with or without stimulation of IL1{beta}. Further analysis indicated that the major COX-2 product, prostaglandin E{sub 2}, directly enhanced proliferation and invasiveness of the epithelial cancer cells in the absence of fibroblasts. Moreover, a selective COX-2 inhibitor, NS-398, blocked the proliferative and invasive effect of both normal and cancer associate fibroblasts on the epithelial cancer cells, with or without stimulation of IL-1{beta}. Those results indicate that activation of COX-2 signaling in the fibroblasts plays a major role in promoting proliferation and invasiveness of the epithelial cancer cells. In this process, PKC is involved in the activation of COX-2 signaling induced by IL-1{beta} in the fibroblasts.

Zhu, Yingting, E-mail: yitizhu@yahoo.com [University of Arizona Arizona Cancer Center Tissue Tech Inc, 7000 SW 97th Avenue Suite 212, Miami, FL 33173 (United States) [University of Arizona Arizona Cancer Center Tissue Tech Inc, 7000 SW 97th Avenue Suite 212, Miami, FL 33173 (United States); Tissue Tech Inc, Miami, FL 33173 (United States); Zhu, Min; Lance, Peter [University of Arizona Arizona Cancer Center Tissue Tech Inc, 7000 SW 97th Avenue Suite 212, Miami, FL 33173 (United States)] [University of Arizona Arizona Cancer Center Tissue Tech Inc, 7000 SW 97th Avenue Suite 212, Miami, FL 33173 (United States)

2012-11-15

127

An observational study of the discrediting of COX-2 NSAIDs in Australia: Vioxx or class effect?  

PubMed Central

Background When a medicine such as rofecoxib (Vioxx) is withdrawn, or a whole class of medicines discredited such as the selective COX-2 inhibitors (COX-2s), follow-up of impacts at consumer level can be difficult and costly. The Australian Longitudinal Study on Women's Health provides a rare opportunity to examine individual consumer medicine use following a major discrediting event, the withdrawal of rofecoxib and issuing of safety warnings on the COX-2 class of medicines. The overall objective of this paper was to examine the impact of this discrediting event on dispensing of the COX-2 class of medicines, by describing medicine switching behaviours of older Australian women using rofecoxib in September 2004; the uptake of other COX-2s; and the characteristics of women who continued using a COX-2. Methods Participants were concessional beneficiary status women from the Older cohort (born 1921-26) of the Australian Longitudinal Study on Women's Health who consented to linkage to Pharmaceutical Benefits Scheme data, with at least one rofecoxib prescription dispensed in the 12 months before rofecoxib withdrawal. A prescription was defined as one dispensing occasion. Women were grouped by rofecoxib pattern of use: continuous (nine or more prescriptions dispensed in the 12 months prior to rofecoxib withdrawal) or non-continuous (eight or less prescriptions dispensed in the 12 months prior to rofecoxib withdrawal) users. Incidence rate per 100,000 person days and incidence risk ratio described uptake of alternate medicines, following rofecoxib withdrawal. Kaplan-Meier curves described differences in uptake patterns by medicine and pattern of rofecoxib use. Patterns of use of COX-2s in the next 100 days after first COX-2 uptake were described. Results Medicine switches and pattern of medicines uptake differed significantly depending upon whether a woman was a continuous or non-continuous rofecoxib user prior to rofecoxib discrediting. Continuous rofecoxib users overwhelmingly switched to another COX-2 and remained continuing COX-2 users for at least 100 days post-switch. Conclusions The typical switching behaviour of this group of women suggests that the issues leading to the discrediting of rofecoxib were not seen as a COX-2 class effect by prescribers to this high use group of consumers. PMID:22114865

2011-01-01

128

Multiple roles of COX-2 in tumor angiogenesis: a target for antiangiogenic therapy.  

PubMed

Angiogenesis is required for multistage carcinogenesis. The inducible enzyme cyclooxygenase-2 (COX-2) is an important mediator of angiogenesis and tumor growth. COX-2 expression occurs in a wide range of preneoplastic and malignant conditions; and the enzyme has been localized to the neoplastic cells, endothelial cells, immune cells, and stromal fibroblasts within tumors. The proangiogenic effects of COX-2 are mediated primarily by three products of arachidonic metabolism: thromboxane A(2) (TXA(2)), prostaglandin E(2) (PGE(2)), and prostaglandin I(2) (PGI(2)). Downstream proangiogenic actions of these eicosanoid products include: (1) production of vascular endothelial growth factor; (2) promotion of vascular sprouting, migration, and tube formation; (3) enhanced endothelial cell survival via Bcl-2 expression and Akt signaling; (4) induction of matrix metalloproteinases; (5) activation of epidermal growth factor receptor-mediated angiogenesis; and (6) suppression of interleukin-12 production. Selective inhibition of COX-2 activity has been shown to suppress angiogenesis in vitro and in vivo. Because these agents are safe and well tolerated, selective COX-2 inhibitors could have clinical utility as antiangiogenic agents for cancer prevention, as well as for intervention in established disease alone or in combination with chemotherapy, radiation, and biological therapies. PMID:15179620

Gately, Stephen; Li, William W

2004-04-01

129

Involvement of COX2-thromboxane pathway in TCDD-induced precardiac edema in developing zebrafish.  

PubMed

The cardiovascular system is one of the most characteristic and important targets for developmental toxicity by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in fish larvae. However, knowledge of the mechanism of TCDD-induced edema after heterodimerization of aryl hydrocarbon receptor type 2 (AHR2) and AHR nuclear translocator type 1 (ARNT1) is still limited. In the present study, microscopic analysis with a high-speed camera revealed that TCDD increased the size of a small cavity between the heart and body wall in early eleutheroembryos, a toxic effect that we designate as precardiac edema. A concentration-response curve for precardiac edema at 2 days post fertilization (dpf) showed close similarity to that for conventional pericardial edema at 3 dpf. Precardiac edema caused by TCDD was reduced by morpholino knockdown of AHR2 and ARNT1, as well as by an antioxidant (ascorbic acid). A selective inhibitor of cyclooxygenase type 2 (COX2), NS398, also markedly inhibited TCDD-induced precardiac edema. A thromboxane receptor (TP) antagonist, ICI-192,605 almost abolished TCDD-induced precardiac edema and this effect was canceled by U46619, a TP agonist, which was not influential in the action of TCDD by itself. Knockdown of COX2b and thromboxane A synthase 1 (TBXS), but not COX2a, strongly reduced TCDD-induced precardiac edema. Knockdown of COX2b was without effect on mesencephalic circulation failure caused by TCDD. The edema by TCDD was also inhibited by knockdown of c-mpl, a thrombopoietin receptor necessary for thromobocyte production. Finally, induction of COX2b, but not COX2a, by TCDD was seen in eleutheroembryos at 3 dpf. These results suggest a role of the COX2b-thromboxane pathway in precardiac edema formation following TCDD exposure in developing zebrafish. PMID:24858302

Teraoka, Hiroki; Okuno, Yuki; Nijoukubo, Daisuke; Yamakoshi, Ayumi; Peterson, Richard E; Stegeman, John J; Kitazawa, Takio; Hiraga, Takeo; Kubota, Akira

2014-09-01

130

Preclinical pharmacology of lumiracoxib: a novel selective inhibitor of cyclooxygenase-2.  

PubMed

1. This manuscript presents the preclinical profile of lumiracoxib, a novel cyclooxygenase-2 (COX-2) selective inhibitor. 2. Lumiracoxib inhibited purified COX-1 and COX-2 with K(i) values of 3 and 0.06 microM, respectively. In cellular assays, lumiracoxib had an IC(50) of 0.14 microM in COX-2-expressing dermal fibroblasts, but caused no inhibition of COX-1 at concentrations up to 30 microM (HEK 293 cells transfected with human COX-1). 3. In a human whole blood assay, IC(50) values for lumiracoxib were 0.13 microM for COX-2 and 67 microM for COX-1 (COX-1/COX-2 selectivity ratio 515). 4. Lumiracoxib was rapidly absorbed following oral administration in rats with peak plasma levels being reached between 0.5 and 1 h. 5. Ex vivo, lumiracoxib inhibited COX-1-derived thromboxane B(2) (TxB(2)) generation with an ID(50) of 33 mg kg(-1), whereas COX-2-derived production of prostaglandin E(2) (PGE(2)) in the lipopolysaccharide-stimulated rat air pouch was inhibited with an ID(50) value of 0.24 mg kg(-1). 6. Efficacy of lumiracoxib in rat models of hyperalgesia, oedema, pyresis and arthritis was dose-dependent and similar to diclofenac. However, consistent with its low COX-1 inhibitory activity, lumiracoxib at a dose of 100 mg kg(-1) orally caused no ulcers and was significantly less ulcerogenic than diclofenac (P<0.05). 7. Lumiracoxib is a highly selective COX-2 inhibitor with anti-inflammatory, analgesic and antipyretic activities comparable with diclofenac, the reference NSAID, but with much improved gastrointestinal safety. PMID:15655513

Esser, Ronald; Berry, Carol; Du, Zhengming; Dawson, Janet; Fox, Alyson; Fujimoto, Roger A; Haston, William; Kimble, Earl F; Koehler, Julie; Peppard, Jane; Quadros, Elizabeth; Quintavalla, Joseph; Toscano, Karen; Urban, Laszlo; van Duzer, John; Zhang, Xiaoli; Zhou, Siyuan; Marshall, Paul J

2005-02-01

131

Suppression of Intestinal Polyposis in Apc ?716 Knockout Mice by Inhibition of Cyclooxygenase 2 (COX2)  

Microsoft Academic Search

Two cyclooxygenase isozymes catalyze conversion of arachidonic acid to prostaglandin H2: constitutive COX-1 and inducible COX-2. To assess the role of COX-2 in colorectal tumorigenisis, we determined the effects of COX-2 gene (Ptgs2) knockouts and a novel COX-2 inhibitor on Apc?716knockout mice, a model of human familial adenomatous polyposis. A Ptgs2null mutation reduced the number and size of the intestinal

Masanobu Oshima; Joseph E Dinchuk; Stacia L Kargman; Hiroko Oshima; Bruno Hancock; Elizabeth Kwong; James M Trzaskos; Jilly F Evans; Makoto M Taketo

1996-01-01

132

Renal protective effect of chronic inhibition of COX-2 with SC-58236 in streptozotocin-diabetic rats.  

PubMed

The induction of renal cyclooxygenase-2 (COX-2) in diabetes has been implicated in the renal functional and structural changes in models where hypertension or uninephrectomy was superimposed. We examined the protective effects of 3 mo treatment of streptozotocin-diabetic rats with a highly selective COX-2 inhibitor (SC-58236) in terms of albuminuria, renal hypertrophy, and the excretion of TNF-? and TGF-?, which have also been implicated in the detrimental renal effects of diabetes. SC-58236 treatment (3 mg·kg(-1)·day(-1)) of diabetic rats resulted in reduced urinary excretion of PGE(2), 6-ketoPGF(1?), and thromboxane B(2), all of which were increased in the diabetic rat compared with age-matched nondiabetic rats. However, serum thromboxane B(2) levels were unchanged, confirming the selectivity of SC-58236 for COX-2. The renal protective effects of treatment of diabetic rats with the COX-2 inhibitor were reflected by a marked reduction in albuminuria, a reduction in kidney weight-to-body weight ratio, and TGF-? excretion and a marked decrease in the urinary excretion of TNF-?. The protective effects of SC-58236 were independent of changes in plasma glucose levels or serum advanced glycation end-product levels, which were not different from those of untreated diabetic rats. In an additional study, the inhibition of COX-2 with SC-58236 for 4 wk in diabetic rats resulted in creatinine clearance rates not different from those of control rats. These results confirm that the inhibition of COX-2 in the streptozotocin-diabetic rat confers renal protection and suggest that the induction of COX-2 precedes the increases in cytokines, TNF-?, and TGF-?. PMID:21441310

Quilley, J; Santos, M; Pedraza, P

2011-06-01

133

Design, synthesis, and biological evaluation of 6-substituted-3-(4-methanesulfonylphenyl)-4-phenylpyran-2-ones: a novel class of diarylheterocyclic selective cyclooxygenase-2 inhibitors.  

PubMed

A group of 6-alkyl (alkoxy or alkylthio)-4-aryl-3-(4-methanesulfonylphenyl)pyran-2-ones (14a-v), possessing either a H or F substituent at the para-position of the C-4 phenyl ring, were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors with in vivo antiinflammatory-analgesic activities. Although 6-ethylthio-3-(4-methanesulfonylphenyl)-4-phenylpyran-2-one (14s) exhibited a very high in vitro COX-2 inhibitory potency (IC(50) = 0.0032 muM) and COX-2 selectivity (SI > 120 000), 14s exhibited moderate antiinflammatory activity compared to celecoxib in a carrageenan-induced rat paw edema assay. In contrast, the less potent (IC(50) = 0.10 muM), and less selective (SI = 2880) COX-2 inhibitor 6-ethoxy-3-(4-methanesulfonylphenyl)-4-phenylpyran-2-one (14i) exhibited good antiinflammatory activity where a 1 mg/kg oral dose reduced inflammation 32 and 67% at 3 and 5 h postdrug administration relative to the reference drug celecoxib where a 50 mg/kg oral dose reduced inflammation by 79 and 58% at the respective 3 and 5 h time periods. Molecular modeling studies, where 14i was docked in the active site of both COX-1 and COX-2, reveals that the C-6 ethoxy substituent orients the pyran-2-one ring to position the SO(2)Me pharmacophore in the vicinity of the secondary pocket in COX-2. The absence of this COX-2 secondary pocket in the COX-1 binding site is due to the presence of the bulky Ile(523) in COX-1 such that access to the amino acid residues (Ile(517), Phe(518), Gln(192), and His(90)), which line the COX-2 secondary pocket with which the SO(2)Me pharmacophore could interact, is hindered. The six-membered pyran-2-one ring system is a suitable central template to design selective COX-2 inhibitors. PMID:14584938

Praveen Rao, P N; Amini, Mohsen; Li, Huiying; Habeeb, Amgad G; Knaus, Edward E

2003-11-01

134

Avian Influenza A H7N9 Virus Induces Severe Pneumonia in Mice without Prior Adaptation and Responds to a Combination of Zanamivir and COX-2 Inhibitor  

PubMed Central

Background Human infection caused by the avian influenza A H7N9 virus has a case-fatality rate of over 30%. Systematic study of the pathogenesis of avian H7N9 isolate and effective therapeutic strategies are needed. Methods BALB/c mice were inoculated intranasally with an H7N9 virus isolated from a chicken in a wet market epidemiologically linked to a fatal human case, (A/chicken/Zhejiang/DTID-ZJU01/2013 [CK1]), and with an H7N9 virus isolated from a human (A/Anhui/01/2013 [AH1]). The pulmonary viral loads, cytokine/chemokine profiles and histopathological changes of the infected mice were compared. The therapeutic efficacy of a non-steroidal anti-inflammatory drug (NSAID), celecoxib, was assessed. Results Without prior adaptation, intranasal inoculation of 106 plaque forming units (PFUs) of CK1 caused a mortality rate of 82% (14/17) in mice. Viral nucleoprotein and RNA expression were limited to the respiratory system and no viral RNA could be detected from brain, liver and kidney tissues. CK1 caused heavy alveolar inflammatory exudation and pulmonary hemorrhage, associated with high pulmonary levels of proinflammatory cytokines. In the mouse lung cell line LA-4, CK1 also induced high levels of interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2) mRNA. Administration of the antiviral zanamivir did not significantly improve survival in mice infected with CK1, but co-administration of the non-steroidal anti-inflammatory drug (NSAID) celecoxib in combination with zanamivir improved survival and lung pathology. Conclusions Our findings suggested that H7N9 viruses isolated from chicken without preceding trans-species adaptation can cause lethal mammalian pulmonary infection. The severe proinflammatory responses might be a factor contributing to the mortality. Treatment with combination of antiviral and NSAID could ameliorate pulmonary inflammation and may improve survival. PMID:25232731

Zhang, Anna J. X.; To, Kelvin K. W.; Lee, Andrew C. Y.; Zhu, Houshun; Wu, Hazel W. L.; Chan, Jasper F. W.; Chen, Honglin; Hung, Ivan F. N.; Li, Lanjuan; Yuen, Kwok-Yung

2014-01-01

135

Signal Transduction Pathway Analysis in Desmoid-type Fibromatosis: TGF?, COX2 and Sex Steroid Receptors  

PubMed Central

Summary Despite reports of sex steroid receptor and COX2 expression in desmoid-type fibromatosis, responses to single agent therapy with anti-estrogens and nonsteroidal anti-inflammatory drugs are unpredictable. Perhaps combination pharmacotherapy might be more effective in desmoid tumors that co-express these targets. Clearly, a further understanding of the signaling pathways deregulated in desmoid tumors is essential for development of targeted molecular therapy. Transforming growth factor-? (TGF?) and bone morphogenetic proteins (BMPs) are important regulators of fibroblast proliferation and matrix deposition, but little is known about the TGF? superfamily in fibromatosis. A tissue microarray representing 27 desmoid tumors was constructed; 14 samples of healing scar and 6 samples of normal fibrous tissue were included for comparison. Expression of selected receptors and activated downstream transcription factors of TGF? family signaling pathways, ?-catenin, sex steroid hormone receptors and COX2 were assessed by immunohistochemistry; patterns of co-expression were explored via correlational statistical analyses. In addition to ?-catenin, immunoreactivity for phosphorylated SMAD2/3 (indicative of active TGF? signaling) and COX2 was significantly increased in desmoid tumors compared to healing scar and quiescent fibrous tissue. Low levels of phosphorylated SMAD1/5/8 were detected in only a minority of cases. TGF? receptor type 1 and androgen receptor were expressed in both desmoid tumors and scar, but not in fibrous tissue. Estrogen receptor-? was present in all cases studied. TGF? signaling appears to be activated in desmoid-type fibromatosis and phosphorylated SMAD2/3 and COX2 immunoreactivity may be of diagnostic utility in these tumors. Given the frequency of androgen receptor, estrogen receptor-? and COX2 co-expression in desmoid tumors, further assessment of the efficacy of combination pharmacotherapy using hormonal agonists/antagonists together with COX2 inhibitors should be considered. PMID:23035734

Mignemi, Nicholas A.; Itani, Doha M.; Fasig, John H.; Keedy, Vicki L.; Hande, Kenneth R.; Whited, Brent W.; Homlar, Kelly C.; Correa, Hernan; Coffin, Cheryl M.; Black, Jennifer O.; Yi, Yajun; Halpern, Jennifer L.; Holt, Ginger E.; Schwartz, Herbert S.; Schoenecker, Jonathan G.; Cates, Justin M. M.

2014-01-01

136

Induction of COX-2 protein expression by vanadate in A549 human lung carcinoma cell line through EGF receptor and p38 MAPK-mediated pathway  

SciTech Connect

Vanadate is a transition metal widely distributed in the environment. It has been reported that vanadate associated with air pollution particles can modify DNA synthesis, causing cell growth arrest, and apoptosis. Moreover, vanadium exposure was also found to cause the synthesis of inflammatory cytokines, such as interleukin-1, tumor necrosis factor-{alpha}, and prostaglandin E{sub 2}. Here, we found that exposure of A549 human lung carcinoma cells to vanadate led to extracellular signal-regulated kinase, c-Jun NH{sub 2}-terminal protein kinases (JNKs), p38 mitogen-activated protein kinase (p38) activation, and COX-2 protein expression in a dose-dependent manner. SB203580, a p38 MAPK inhibitor, but not PD098059 and SP600125, specific inhibitor of MKK1 and selective inhibitor of JNK, respectively, suppressed COX-2 expression. Furthermore, the epithelial growth factor (EGF) receptor specific inhibitor (PD153035) reduced vanadate-induced COX-2 expression. However, scavenging of vanadate-induced reactive oxygen species by catalase, a specific H{sub 2}O{sub 2} inhibitor, or DPI, an NADPH oxidase inhibitor, resulted in no inhibition on COX-2 expression. Together, we suggested that EGF receptor and p38 MAPK signaling pathway may be involved in vanadate-induced COX-2 protein expression in A549 human lung carcinoma cell line.

Chien, P.-S. [Institute of Biotechnology, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China); Mak, O.-T. [Institute of Biotechnology, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China); Department of Life Sciences, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China); Huang, H.-J. [Institute of Biotechnology, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China) and Department of Life Sciences, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China)]. E-mail: haojen@mail.ncku.edu.tw

2006-01-13

137

Molecular Dynamics Simulations of Arachidonic Acid Complexes with COX-1 and COX-2  

PubMed Central

The cyclooxygenase (COX) enzymes are responsible for the committed step in prostaglandin biosynthesis, the generation of prostaglandin H2. As a result, these enzymes are pharmacologically important targets for non-steroidal anti-inflammatory drugs, such as aspirin and newer COX-2 selective inhibitors. The cyclooxygenases are functional homodimers, and each subunit contains both a cyclooxygenase and a peroxidase active site. These enzymes are quite interesting mechanistically, as the conversion of arachidonic acid to prostaglandin H2 requires two oxygenation and two cyclization reactions, resulting in the formation of five new chiral centers with nearly absolute regio- and stereochemical fidelity. We have used molecular dynamics (MD) simulations to investigate the equilibrium behavior of both COX-1 and COX-2 enzyme isoforms with bound arachidonate. These simulations were compared with reference simulations of arachidonate in solution to explore the effect of enzyme on substrate conformation and positioning in the active site. The simulations suggest that the substrate has greater conformational freedom in the COX-2 active site, consistent with the larger COX-2 active site volume observed in X-ray crystal structures. The simulations reveal different conformational behavior for arachidonate in each subunit over the course of extended equilibrium MD simulations. The simulations also provide detailed information for several protein channels that might be important for oxygen and water transport to or from active sites, or for intermediate trafficking between the cyclooxygenase and peroxidase active sites. The detailed comparisons for COX-1 versus COX-2 active site structural fluctuations may also provide useful information for design of new isozyme-selective inhibitors. PMID:16519514

Furse, Kristina E.; Pratt, Derek A.; Porter, Ned A.; Lybrand, Terry P.

2008-01-01

138

Cancer Chemoprevention by Cyclooxygenase 2 (COX2) Blockade  

Microsoft Academic Search

Significant use of selective cyclooxygenase-2 (COX-2) blocking agents prescribed for the treatment of arthritis during 1999\\u000a to 2005 facilitates epidemiologic investigations to illuminate their chemopreventive effects against human cancer. We therefore\\u000a conducted a set of case control studies of selective COX-2 blocking agents to determine their chemopreventive potential for\\u000a the four major cancers: breast, prostate, colon, and lung. Newly diagnosed

RANDALL E. HARRIS; Joanne Beebe-Donk; GALAL A. ALSHAFIE

139

A new class of acyclic 2-alkyl-1,1,2-triaryl (Z)-olefins as selective cyclooxygenase-2 inhibitors.  

PubMed

A new class of acyclic (Z)-2-alkyl-1,2-diphenyl-1-(4-methanesulfonylphenyl)ethenes (7) was designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. In vitro COX-1 and COX-2 isozyme inhibition structure-activity studies identified (Z)-1,2-diphenyl-1-(4-methanesulfonylphenyl)oct-1-ene (7d) as a potent COX-2 inhibitor (IC(50) = 0.42 microM) with a high COX-2 selectivity index (SI > 234). In a carrageenan-induced rat paw edema assay, (Z)-7d exhibited excellent antiinflammatory activity (ID(50) = 1.1 mg/kg). The molecular modeling and structure-activity data acquired indicate that (Z)-olefins having cis C-1 4-methanesulfonylphenyl and C-2 unsubstituted phenyl (or 4-acetoxyphenyl) substituents in conjunction with a C-1 phenyl ring and a C-2 alkyl substituent of appropriate length constitute a suitable template for the design of a novel class of acyclic (Z)-2-alkyl-1,1,2-triaryleth-1-ene COX-2 inhibitors. PMID:15537365

Uddin, Md Jashim; Praveen Rao, P N; McDonald, Robert; Knaus, Edward E

2004-11-18

140

Overexpression of Cyclooxygenase-2 in Malignant Peripheral Nerve Sheath Tumor and Selective Cyclooxygenase-2 Inhibitor-Induced Apoptosis by Activating Caspases in Human Malignant Peripheral Nerve Sheath Tumor Cells  

PubMed Central

Background Cyclooxygenase-2 (COX-2) is a key enzyme in the conversion of arachidonic acid to prostanoids, and its activation is associated with carcinogenesis as well as inflammation. The antitumor effect of selective COX-2 inhibitors has been noted in various malignancies. Malignant peripheral nerve sheath tumor (MPNST) is a rare and aggressive soft tissue sarcoma for which effective treatments have not yet been established. The purpose of this study was to investigate a potential therapeutic role of COX-2 in MPNST. Methods We evaluated the expression of COX-2 in 44 cases of high-grade MPNST using immunohistochemical staining and compared the staining results with the characteristics and outcome of the patients. We also investigated the antitumor effect of etodolac, a selective COX-2 inhibitor, on MPNST cells in vitro using the MPNST cell line, FMS-1. Results Overexpression of COX-2 (?50% positive cells) was observed in 29 cases (65.9%), was significantly associated with a poor overall survival (P?=?0.0495), and was considered an independent risk factor for a poor outcome by the results of both univariate and multivariate analysis. Etodolac induced apoptosis of FMS-1 cells through the activation of caspase-8, -9, and -3. Moreover, several caspase inhibitors significantly inhibited etodolac-induced apoptosis. Conclusions Selective COX-2 inhibitors including etodolac had an antitumor effect on MPNST cells, and their use holds promise as a novel therapeutic strategy for patients with MPNST to improve their prognoses. PMID:24516579

Hakozaki, Michiyuki; Tajino, Takahiro; Konno, Shinichi; Kikuchi, Shinichi; Yamada, Hitoshi; Yanagisawa, Michiro; Nishida, Jun; Nagasawa, Hiroyuki; Tsuchiya, Takashi; Ogose, Akira; Abe, Masafumi; Hojo, Hiroshi

2014-01-01

141

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

PubMed

The present study was aimed to test the possible cyclooxygenase (COX)-1/COX-2 selectivity of the old analgesic drug phenacetin and its metabolite p-phenetidine, which exhibits high renal toxicity. Paracetamol (acetaminophen), the main metabolite of phenacetin with low renal toxicity, and indomethacin were selected as reference compounds. Collagen-stimulated platelet thromboxane B2 (TxB2) production and phorbol 12-myristate-13-acetate (PMA)-induced neutrophil prostaglandin E2 (PGE2) synthesis were used as indicators for COX-1 and COX-2 activity, respectively. Phenacetin was even less potent than paracetamol to reduce the production of both TxB2 and PGE2, and no clear preference for either of the COX-enzymes was seen. P-phenetidine was a more potent inhibitor, already at nanomolar level, of the synthesis of these prostanoids than indomethacin and showed some preference to COX-2 inhibition. Somewhat higher, micromolar, concentrations of p-phenetidine also reduced COX-2 expression in neutrophils. We suggest that the very potent inhibitory activity of p-phenetidine on PGE2 synthesis combined with the reduction of COX-2 expression could explain the renal papillary necrosis in phenacetin kidney. PMID:14592552

Kankuri, Esko; Solatunturi, Erkka; Vapaatalo, Heikki

2003-06-15

142

1,2Diaryl1-ethanone and pyrazolo [4,3- c] quinoline-4-one as novel selective cyclooxygenase-2 inhibitors  

Microsoft Academic Search

Novel 1,2-diaryl-1-ethanone 1 and pyrazolo [4,3-c] quinoline-4-one 2, with pharmacophores different from the known COX inhibitors were identified as selective COX-2 inhibitors. The communication briefly describes SAR of both the series.

Bipul Baruah; Kavitha Dasu; Balasubramanian Vaitilingam; Akhila Vanguri; Seshagiri Rao Casturi; Koteswar Rao Yeleswarapu

2004-01-01

143

Design, synthesis, and pharmacological evaluation of pyridinic analogues of nimesulide as cyclooxygenase-2 selective inhibitors.  

PubMed

In this study, we report the synthesis and pharmacological evaluation of original pyridinic sulfonamides related to nimesulide, a cyclooxygenase-2 (COX-2) preferential inhibitor widely used as an anti-inflammatory agent. These original pyridinic derivatives were synthesized in three steps starting from the condensation of 3-bromo-4-nitropyridine N-oxide with appropriately substituted phenols, thiophenols, or anilines followed by a reduction of the nitro moiety into the corresponding aminopyridine, which was finally condensed with alkane- or trifluoromethanesulfonyl chloride to obtain the corresponding sulfonamides. The pK(a) determinations demonstrated that the major ionic form present in solution at physiological pH depends on the nature of the sulfonamide moiety subsituent. Indeed, alkanesulfonamides were mainly present as zwitterionic molecules while trifluoromethanesulfonamides, more acidic derivatives, were mainly present as anionic molecules. The in vitro pharmacological evaluation of the synthesized compounds against COX-1 and COX-2 was performed in a human whole blood model. Results obtained demonstrated that most of alkanesulfonamide derivatives displayed a COX-2 preferential inhibition with selectivity ratio values (IC(50)(COX-1)/IC(50)(COX-2)) up to 7.92 (celecoxib displaying a ratio value of 7.46 in the same test). On the other hand, trifluoromethanesulfonamide derivatives displayed weaker selectivity ratios although they exhibited IC(50) values against COX-2 up to 0.09 microM (celecoxib IC(50) against COX-2: 0.35 microM). Finally, in vivo evaluation of selected compounds showed that they exhibited anti-inflammatory properties similar to that of nimesulide when tested in a carrageenan-induced rat paw oedema model. PMID:15615524

Julémont, Fabien; de Leval, Xavier; Michaux, Catherine; Renard, Jean-François; Winum, Jean-Yves; Montero, Jean-Louis; Damas, Jacques; Dogné, Jean-Michel; Pirotte, Bernard

2004-12-30

144

[Dexketoprofene, selective cox-1 inhibitor nsaids, without gastrointestinal injury in rats].  

PubMed

Dexketoprofene (De) NSAID was studied as a selective COX-1 inhibitor in comparison with Ketorolac (Ke), a mainly COX-1 inhibitor. De and Ke were administered to different groups of animals in a dose-dependent manner, i.e., 3-15 and 25 mgs/kg. The gastrointestinal mucosa damage was macroscopically and microscopically quantified at 24 hs, as well as leukocyte infiltration (LI) and neosinophilia. Similarly, Indomethacin (Indo) damage (COX-1-COX-2), with 25 mgs/kg. Dose was compared. On the other hand, De and Ke at inhibitory selective COX-1 dose (3 mg/kg) plus Celecoxib, selective COX-2 inhibitor, yielding no gastrointestinal damage, with decreased LI and without neutrophilia, the same as Ke (n.s.). Similarly De at higher dose (2.5 mgs/kg), produced minimal gastrointestinal lesions, showing a preferential COX-1 inhibitor behavior. Ke and Indo produced important gastrointestinal necrotic and erosive lesions with remarkable LI and neutrophilia (p < 0.001). On the other hand, COX-1 De dose plus Celecoxib produced evident gastrointestinal lesions, increased LI and neutrophilia, the same as Indo, pointing out that the gastrointestinal damage is due to COX-1 and COX-2 inhibition. PMID:12136686

Laudanno, O M; Piombo, Gabriela; Cesolari, J A M; Godoy, Alicia; Rocaspana, Adriana; Aramberry, L

2002-05-01

145

COX-2 Protects against Atherosclerosis Independently of Local Vascular Prostacyclin: Identification of COX-2 Associated Pathways Implicate Rgl1 and Lymphocyte Networks  

PubMed Central

Cyxlo-oxygenase (COX)-2 inhibitors, including traditional nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with increased cardiovascular side effects, including myocardial infarction. We and others have shown that COX-1 and not COX-2 drives vascular prostacyclin in the healthy cardiovascular system, re-opening the question of how COX-2 might regulate cardiovascular health. In diseased, atherosclerotic vessels, the relative contribution of COX-2 to prostacyclin formation is not clear. Here we have used apoE?/?/COX-2?/? mice to show that, whilst COX-2 profoundly limits atherosclerosis, this protection is independent of local prostacyclin release. These data further illustrate the need to look for new explanations, targets and pathways to define the COX/NSAID/cardiovascular risk axis. Gene expression profiles in tissues from apoE?/?/COX-2?/? mice showed increased lymphocyte pathways that were validated by showing increased T-lymphocytes in plaques and elevated plasma Th1-type cytokines. In addition, we identified a novel target gene, rgl1, whose expression was strongly reduced by COX-2 deletion across all examined tissues. This study is the first to demonstrate that COX-2 protects vessels against atherosclerotic lesions independently of local vascular prostacyclin and uses systems biology approaches to identify new mechanisms relevant to development of next generation NSAIDs. PMID:24887395

Kirkby, Nicholas S.; Lundberg, Martina H.; Wright, William R.; Warner, Timothy D.; Paul-Clark, Mark J.; Mitchell, Jane A.

2014-01-01

146

Heterogeneous gene expression changes in colorectal cancer cells share the WNT pathway in response to growth suppression by APHS-mediated COX-2 inhibition  

PubMed Central

Cyclooxygenase-2 (COX-2), the prostaglandin (PG)-synthesizing enzyme overexpressed in colorectal cancer (CRC), has pleiotropic, cancer-promoting effects. COX-2 inhibitors (CIBs) interfere with many cancer-associated processes and show promising antineoplastic activity, however, a common mechanism of CIB action has not yet been established. We therefore investigated by microarray the global response towards the CIB APHS at a dose significantly inhibiting the growth of three COX-2-positive CRC but not of two COX-2-negative cell lines. None of the genes significantly (p = 0.005) affected by APHS were common to all three cell lines and 83% of the altered pathways were cell line-specific. Quantitative polymerase chain reaction (QPCR) on selected pathways confirmed cell line-specific expression alterations induced by APHS. A low stringency data analysis approach using BRB array tools coupled with QPCR, however, identified small expression changes shared by all COX-2-positive cell lines in genes related to the WNT pathway, the key driver of colonic carcinogenesis. Our data indicates a substantial cell line-specificity of APHS-induced expression alterations in CRC cells and helps to explain the divergent effects reported for CIBs. Further, the shared inhibition of the WNT pathway by APHS suggests one potential common mechanism behind the antineoplastic effects of COX-2 inhibition. PMID:19707365

Humar, Bostjan; McNoe, Les; Dunbier, Anita; Heathcott, Rosemary; Braithwaite, Antony W; Reeve, Anthony E

2008-01-01

147

Alterations in subcellular localization of p38 MAPK potentiates endothelin-stimulated COX-2 expression in glomerular mesangial cells.  

PubMed

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide with mitogenic actions linked to activation of tyrosine kinase signaling pathways. ET-1 induces cyclooxygenase-2 (COX-2), an enzyme that converts arachidonic acid to pro-inflammatory eicosanoids. Activation of each of the three major mitogen-activated protein kinase (MAPK) pathways, ERK1/2, JNK/SAPK, and p38 MAPK (p38), have been shown to enhance the expression of COX-2. Negative regulation of MAPK may occur via a family of dual specificity phosphatases referred to as mitogen-activated protein kinase phosphatases (MKP). The goal of this work was to test the hypothesis that wild type MKP-1 regulates the expression of ET-1-induced COX-2 expression by inhibiting the activation of p38 in cultured glomerular mesangial cells (GMC). An adenovirus expressing both wild type and a catalytically inactive mutant of MKP-1 (MKP-1/CS) were constructed to study ET-1-regulated MAPK signaling and COX-2 expression in cultured GMC. ET-1 stimulated the phosphorylation of ERK and p38 alpha MAPK and induced the expression of COX-2. Expression of COX-2 was partially blocked by U0126, a MEK inhibitor, and SB 203580, a p38 MAPK inhibitor. Adenoviral expression of MKP-1/CS augmented basal and ET-1-induced phosphorylation of p38 alpha MAPK with less pronounced effects on ERK1/2 phosphorylation. Ectopic expression of wild type MKP-1 blocked the phosphorylation of p38 alpha MAPK by ET-1 but increased the phosphorylation of p38 gamma MAPK. Co-precipitation studies demonstrated association of MKP-1 with p38 alpha MAPK and ERK1/2. Immunofluorescent image analysis demonstrated trapping of phospho-p38 MAPK in the cytoplasm by MKP-1/CS/green fluorescent protein. ET-1-stimulated expression of COX-2 was increased in MKP-1/CS versus LacZ or green fluorescent protein-infected control cells. These results indicate that MKP-1 demonstrates a relative selectivity for p38 alpha MAPK versus p38 gamma MAPK in GMC and is likely to indirectly regulate the expression of COX-2. PMID:14530261

Pratt, Phillip F; Bokemeyer, Dirk; Foschi, Marco; Sorokin, Andrey; Dunn, Michael J

2003-12-19

148

Molecular dynamics simulations of arachidonic acid complexes with COX-1 and COX-2: insights into equilibrium behavior.  

PubMed

The cyclooxygenase (COX) enzymes are responsible for the committed step in prostaglandin biosynthesis, the generation of prostaglandin H(2). As a result, these enzymes are pharmacologically important targets for nonsteroidal antiinflammatory drugs, such as aspirin and newer COX-2 selective inhibitors. The cyclooxygenases are functional homodimers, and each subunit contains both a cyclooxygenase and a peroxidase active site. These enzymes are quite interesting mechanistically, as the conversion of arachidonic acid to prostaglandin H(2) requires two oxygenation and two cyclization reactions, resulting in the formation of five new chiral centers with nearly absolute regio- and stereochemical fidelity. We have used molecular dynamics (MD) simulations to investigate the equilibrium behavior of both COX-1 and COX-2 enzyme isoforms with bound arachidonate. These simulations were compared with reference simulations of arachidonate in solution to explore the effect of enzyme on substrate conformation and positioning in the active site. The simulations suggest that the substrate has greater conformational freedom in the COX-2 active site, consistent with the larger COX-2 active site volume observed in X-ray crystal structures. The simulations reveal different conformational behavior for arachidonate in each subunit over the course of extended equilibrium MD simulations. The simulations also provide detailed information for several protein channels that might be important for oxygen and water transport to or from active sites or for intermediate trafficking between the cyclooxygenase and peroxidase active sites. The detailed comparisons for COX-1 versus COX-2 active site structural fluctuations may also provide useful information for design of new isozyme-selective inhibitors. PMID:16519514

Furse, Kristina E; Pratt, Derek A; Porter, Ned A; Lybrand, Terry P

2006-03-14

149

Role of selective cyclooxygenase-2 inhibitors in exacerbation of inflammatory bowel disease: A systematic review and meta-analysis  

PubMed Central

Background: In the general population, selective cyclooxygenase (COX)-2 inhibitors have been associated with fewer gastrointestinal adverse effects (AEs) than NSAIDs, but whether they are associated with exacerbations in patients with inflammatory bowel disease (IBD) remains controversial. Objective: The aim of this study was to review published and unpublished findings to determine whether the use of COX-2 inhibitors increased the risk for IBD exacerbations relative to placebo in the treatment of IBD. Methods: A systematic search of MEDLINE (1966-July 2007), EMBASE (1980-July 2007), the Cochrane Library (2007 Issue 4), US Food and Drug Administration records, and data on file at Novartis Pharmaceuticals Corporation, Pfizer US Pharmaceutical Group, and Merck & Co., Inc., using the search terms celecoxib, rofecoxib, valdecoxib, etoricoxib, lumiracoxib, cyclooxygenase 2 inhibitor, Crohn's disease, ulcerative colitis, and inflammatory bowel disease, was performed to identify randomized, placebo-controlled clinical trials of 5 COX-2 inhibitors in patients with IBD. The publications were fully reviewed for quality. Data on trial design, patient characteristics, intervention drugs, dosages, and outcomes were collected using a predetermined data-extraction form. A meta-analysis was performed based on the publications that met the inclusion/exclusion criteria. Results: Of 588 studies identified in the electronic search, 574 were excluded after screening the titles and abstracts. Fourteen related to the use of COX-2 inhibitors in patients with IBD were reviewed. Two randomized, controlled trials comparing COX-2 inhibitors with placebo were identified. In the first trial, 82 patients were randomized to receive etoricoxib (60–120 mg/d) and 77 to receive placebo. The exacerbation rates were 10.5% (8/76) in the active-treatment group and 11.4% (8/70) in the placebo group (relative risk [RR], 0.92; 95% CI, 0.37–2.32). In the second trial, 112 patients were treated with celecoxib (200 mg BID) and 110 received placebo. The exacerbation rates were 3.7% (4/107) in the celecoxib group and 2.7% (3/110) in the placebo group (RR, 0.73; 95% CI, 0.17–3.18). Of these patients, 5 were lost to follow-up because of AEs. In the meta-analysis comparing COX-2 inhibitors and placebo, the RR was 0.86 (95% CI, 0.39–1.88). No statistically significant differences in IBD relapse rates were found between COX-2 inhibitors and placebo. Conclusions: The results from this meta-analysis suggest that insufficient data were available to determine the impact of COX-2 inhibitors on IBD exacerbations. The relatively smaller risk for AEs makes the short-term use of COX-2 inhibitors potentially attractive, but the long-term benefits remain unclear. Further studies with sound methodology and large sample sizes are needed to evaluate the tolerability of COX-2 inhibitors in the treatment of IBD. PMID:24692797

Miao, Xin-Pu; Ouyang, Qin; Li, Hui-Yan; Wen, Zhong-Hui; Zhang, De-Kui; Cui, Xiao-Yan

2008-01-01

150

Exploring the cyclooxygenase 2 (COX2)/15d-?(12,14)PGJ(2) system in hamster Sertoli cells: regulation by FSH/testosterone and relevance to glucose uptake.  

PubMed

We have previously described a stimulatory effect of testosterone on cyclooxygenase 2 (COX2) expression and prostaglandin (PG) synthesis, and the involvement of PGs in the modulation of testosterone production in Leydig cells of the seasonal breeder Syrian hamster. In this study, we investigated the existence of a COX2/PGs system in hamster Sertoli cells, its regulation by testosterone and FSH, and its effect on glucose uptake. COX2 expression was observed in Sertoli cells of both reproductively active and inactive adult hamsters. Testosterone and the plasma membrane-impermeable testosterone-BSA significantly induced COX2 expression, mitogen activated protein kinases 1/2 (MAPK1/2) phosphorylation and 15d-?(12,14)PGJ(2) production in Sertoli cells purified from photoperiodically regressed hamsters. These actions were abolished by the antiandrogen bicalutamide and by the inhibitor of MAPK kinase (MEK1/2) U0126, suggesting that testosterone exerts its stimulatory effect on COX2/PGs through a non-classical mechanism that involves the presence of androgen receptors and MAPK1/2 activation. FSH also stimulated COX2/PGs via MAPK1/2 phosphorylation. FSH and testosterone stimulate, whereas 15d-?(12,14)PGJ(2) via PPAR? inhibits, [2,6-(3)H]-2-deoxy-d-glucose ([(3)H]-2-DOG) uptake. Meloxicam, a selective COX2 inhibitor, further increases [(3)H]-2-DOG uptake in the presence of FSH or testosterone. Thus, in addition to their positive effect, FSH and testosterone may also exert an indirect negative regulation on glucose uptake which involves the COX2/15d-?(12,14)PGJ(2)/PPAR? system. Overall, these results demonstrate the presence of a COX2/PG system in hamster Sertoli cells which might act as a local modulator of FSH and testosterone actions. PMID:22974512

Matzkin, María Eugenia; Pellizzari, Eliana Herminia; Rossi, Soledad Paola; Calandra, Ricardo Saúl; Cigorraga, Selva Beatriz; Frungieri, Mónica Beatriz

2012-11-01

151

Interactions between inducible isoforms of nitric oxide synthase and cyclo-oxygenase in vivo: investigations using the selective inhibitors, 1400W and celecoxib  

PubMed Central

Exposure of tissues to endotoxin (LPS) and/or cytokines leads to the induction of both inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2). It has previously been reported that there is `cross-talk' between these two systems. However, such previous studies have been limited by the availability of highly selective inhibitors. Here we have investigated the interactions between iNOS and COX-2 in vivo using 1400W, an iNOS-selective inhibitor, and celecoxib, a COX-2-selective inhibitor.Infusion of LPS to rats for 6?h caused a time-dependent increase in the plasma concentrations of 6 keto-prostaglandin F1? (6 keto-PGF1?) and nitrite/nitrate (NO2/NO3), consistent with the induction of iNOS and COX-2. Bolus injection of arachidonic acid (AA) at t=6?h resulted in a further increase of circulating levels of 6 keto-PGF1? in LPS-treated animals.Treatment of rats with 1400W or the non-selective NOS inhibitor NG-monomethyl-L-arginine (L-NMMA) inhibited the increase in plasma NO2/NO3 but were both without effect on the plasma concentration of 6 keto-PGF1? before or after AA.Treatment with the non-steroidal anti-inflammatory drugs (NSAIDs), A771726 or diclofenac, or with celecoxib significantly reduced the increase in circulating 6 keto-PGF1? caused by LPS, and the large increase in 6 keto-PGF1? following injection of AA. None of the COX inhibitors affected the increase in plasma NO2/NO3. Dexamethasone, however, significantly inhibited both the increase in 6 keto-PGF1? and the increase in NO2/NO3.In conclusion, the use of selective inhibitors does not support the concept of cross talk in vivo between iNOS and COX-2. PMID:9786506

Hamilton, Lorna C; Warner, Timothy D

1998-01-01

152

Role of COX-2 in the bioactivation of methylenedianiline and in its proliferative effects in vascular smooth muscle cells.  

PubMed

4,4'-Methylenedianiline (DAPM) is an aromatic diamine used directly in the production of polyurethane foams and epoxy resins, or as a precursor to MDI in the manufacture of some polyurethanes. In our prior experiments, we showed that chronic, intermittent treatment of female rats with DAPM resulted in vascular medial hyperplasia of pulmonary arteries. In addition, treatment of vascular smooth muscle cells (VSMC) in culture with DAPM increased the rates of proliferation in a manner that was inhibited by co-treatment with N-acetylcysteine but was not associated with oxidative stress. We thus hypothesized that NAC treatment inhibited DAPM toxicity by competing for binding reactive intermediates formed through DAPM metabolism. Because the peroxidase enzyme cyclooxygenase is constitutively expressed in VSMC, and because cyclooxygenase is known to metabolize similar aromatic amines to electrophilic intermediates, we further hypothesized that DAPM-induced VSMC proliferation was dependent upon COX-1/2-mediated bioactivation. To test this hypothesis, we treated VSMC with DAPM and measured cell proliferation, COX-2 expression, COX-1/2 activity, and levels of covalent binding. DAPM treatment resulted in a dose-dependent increase in proliferation that was abolished by co-treatment with the COX-2-selective inhibitor celecoxib. In addition, DAPM exposure increased the rates of proliferation in VSMC isolated from wild-type but not COX-2 (-/-) mice. Paradoxically, treatment with DAPM reduced the cellular production of PGE(2) and PGF(2?), but dose-dependently increased the COX-2 protein levels. Covalent binding of [(14)C]-DAPM to VSMC biomolecules was greater in wild-type than in COX-2 (-/-) cells. However, covalent binding of [(14)C]-DAPM was not altered by co-treatment with a nonselective inhibitor of cytochromes P450. These studies thus suggest that DAPM-induced VSMC proliferation may be due to bioactivation of DAPM, perhaps through the action of cyclooxygenase. The data furthermore suggest that DAPM's mechanism of action may possibly involve inhibition or suicide inactivation of COX-2. In addition, because we observed an increase in DAPM-induced VSMC proliferation in cells isolated from female compared to male rats, further studies into the potential interplay between DAPM, the estrogen receptor, and COX-2 seem warranted. PMID:21720929

Hebert, Valeria Y; Jones, Brandon Chad; Mifflin, Randy C; Dugas, Tammy R

2011-12-01

153

COX-2 Inhibition by Use of Rofecoxib or High Dose Aspirin Enhances ADP-Induced Platelet Aggregation in Fresh Blood  

PubMed Central

Aim: Increased cardiovascular risk after use of selective or nonselective cyclooxygenase-2 (COX-2)-inhibitors might partly be caused by enhanced platelet aggregability. However, an effect of COX-2 inhibition on platelets has so far not been observed in humans. Methods: We tested in healthy volunteers the effect of COX-2-inhibition nearly in-vivo, i.e. immediately after and even during blood sampling. Results: Measurement within 2 minutes after venipuncture, but not 60 minutes later, showed that 50 mg of rofecoxib (n=12) or 500 (n=8) or 1000 (n=8) mg of aspirin increased ADP-induced platelet aggregation in a whole-blood aggregometer to, respectively, 152, 176 and 204 % of basal level (p<0.01). No significant differences in aggregability were observed after ingestion of 80 mg of aspirin (n=16), or placebo (n=8). Plasma 6-keto-PGF1? was decreased to 74 % after rofecoxib and to 76 and 70 % after 500 and 1000 mg of aspirin but did not change after low dose aspirin. Continuous photometrical measurement of aggregation in blood flowing from a cannulated vein revealed that high dose aspirin did not elicit aggregation by itself, but increased ADP-induced aggregation in proportion to the decrease in prostacyclin formation (r=0.68, p = 0.004). Since in these experiments thromboxane production was virtually absent, the enhanced aggregation after partial COX-2 inhibition was not caused by unopposed thromboxane formation. Conclusions: We conclude that both selective and nonselective COX-2 inhibition enhances ADP-induced platelet aggregation in humans. This effect can only be detected during or immediately after venipuncture, possibly because of the short half-life of prostacyclin. PMID:21331307

Borgdorff, Piet; Handoko, M. Louis; Wong, Yeun Ying; Tangelder, Geert Jan

2010-01-01

154

Distinction of microsomal prostaglandin E synthase-1 (mPGES-1) inhibition from cyclooxygenase-2 inhibition in cells using a novel, selective mPGES-1 inhibitor.  

PubMed

Inflammation-induced microsomal prostaglandin E synthase-1 (mPGES-1) is the terminal enzyme that synthesizes prostaglandin E(2) (PGE(2)) downstream of cyclooxygenase-2 (COX-2). The efficacy of nonsteroidal anti-inflammatory drugs and COX-2 inhibitors in the treatment of the signs and symptoms of osteoarthritis, rheumatoid arthritis and inflammatory pain, largely attributed to the inhibition of PGE(2) synthesis, provides a rationale for exploring mPGES-1 inhibition as a potential novel therapy for these diseases. Toward this aim, we identified PF-9184 as a novel mPGES-1 inhibitor. PF-9184 potently inhibited recombinant human (rh) mPGES-1 (IC(50)=16.5+/-3.8nM), and had no effect against rhCOX-1 and rhCOX-2 (>6500-fold selectivity). In inflammation and clinically relevant biological systems, mPGES-1 expression, like COX-2 expression was induced in cell context- and time-dependent manner, consistent with the kinetics of PGE(2) synthesis. In rationally designed cell systems ideal for determining direct effects of the inhibitors on mPGES-1 function, but not its expression, PF-9184 inhibited PGE(2) synthesis (IC(50) in the range of 0.5-5 microM in serum-free cell and human whole blood cultures, respectively) while sparing the synthesis of 6-keto-PGF(1alpha) (PGF(1alpha)) and PGF(2alpha). In contrast, as expected, the selective COX-2 inhibitor, SC-236, inhibited PGE(2), PGF(1alpha) and PGF(2alpha) synthesis. This profile of mPGES-1 inhibition, distinct from COX-2 inhibition in cells, validates mPGES-1 as an attractive target for therapeutic intervention. PMID:20067770

Mbalaviele, Gabriel; Pauley, Adele M; Shaffer, Alexander F; Zweifel, Ben S; Mathialagan, Sumathy; Mnich, Stephen J; Nemirovskiy, Olga V; Carter, Jeff; Gierse, James K; Wang, Jane L; Vazquez, Michael L; Moore, William M; Masferrer, Jaime L

2010-05-15

155

Heterotypic contact reveals a COX-2-mediated suppression of osteoblast differentiation by endothelial cells: A negative modulatory role for prostanoids in VEGF-mediated cell: cell communication?  

SciTech Connect

In bone, angiogenesis must be initiated appropriately, but limited once remodelling or repair is complete. Our recent findings have supported a role for prostaglandins (PG), known modulators of osteoblast (OB) and endothelial cell (EC) behaviour, in facilitating VEGF-mediated paracrine communication from OBs to 'remotely located' ECs, but the mechanism(s) regulating OB:EC crosstalk when these cells are closely opposed are undefined. In this study we have examined: (i) the effects of exogenous PGE{sub 2} on VEGF-driven events in ECs, and (ii) the role of endogenous COX-2-derived prostanoids in mediating communication between intimately opposed OBs and ECs in direct contact. Exposure of ECs to PGE{sub 2} increased ERK1/2 phosphorylation, COX-2 induction, 6-keto-PGF{sub 1{alpha}} release and EC proliferation. In contrast, PGE{sub 2} attenuated VEGF{sub 165}-induced VEGFR2/Flk1 phosphorylation, ERK1/2 activation and proliferation of ECs, suggesting that exogenous PGE{sub 2} restricts the actions of VEGF. However, the COX-2-selective inhibitor, NS398, also attenuated VEGF-induced proliferation, implying a distinct role for endogenous COX-2 activity in regulating EC behaviour. To examine the effect of OB:EC proximity and the role of COX-2 products further, we used a confrontational co-culture model. These studies showed that COX-2 blockade with NS398 enhanced EC-dependent increases in OB differentiation, that this effect was reversed by exogenous PGH{sub 2} (immediate COX-2 product), and that exogenous VEGF did not influence EC-dependent OB differentiation under these conditions. Our findings indicate that locally produced prostanoids may serve distinct roles depending on OB:EC proximity and negatively modulate VEGF-mediated changes in EC behaviour when these cells are closely opposed to control angiogenesis during bone (re)modelling.

Clarkin, Claire E. [Department of Veterinary Basic Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU (United Kingdom)], E-mail: claire.clarkin@kcl.ac.uk; Garonna, Elena; Pitsillides, Andrew A.; Wheeler-Jones, Caroline P.D. [Department of Veterinary Basic Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU (United Kingdom)

2008-10-15

156

Selectivity of cyclo-oxygenase inhibitors in human pulmonary epithelial and smooth muscle cells.  

PubMed

Cyclo-oxygenase (COX) inhibitors may have a role in reducing inflammation in asthma and other pulmonary diseases. COX inhibitors have different selectivities for the two COX isoenzymes (COX 1 and COX 2) which vary between purified enzyme and intact cell preparations. The relative selectivity of COX inhibitors has not been studied in human airway cells. A number of COX inhibitors in cultured human airway cells were compared which exclusively express either COX 1 (primary degree cultured human airway smooth muscle (HASM) cells) or COX 2 (A549 pulmonary epithelial cell-line) as measured by Western blotting. COX activity was assayed by prostaglandin (PG)E2 production following 30 min incubation with 5 mM arachidonic acid. COX activity in both cell types was similar; HASM cells 92.2+/-12.1 ng PGE2 x mg-1 protein, A549 cells 87.7+/-24.4 ng PGE2 mg-1 protein. In HASM cells the median inhibitory concentration (IC50) was >10-5 M for nimesulide, 3.2 x 10-6 M for N-(2-cyclohexyloxy-4-nitrophenyl)-methanesulphonamide (NS398), 1.8 x 10-8 M for flurbiprofen, 6.7 x 10-9 M for indomethacin and >10-5 M for aspirin. In A549 cells the IC50 was 1.8 x 10-9M for nimesulide, 4.1 x 10-9 M for NS398,6.2 x 10-10 M for flurbiprofen, 1.3 x 10-8 M for indomethacin and >10-5 M for aspirin. Sodium valerate had no effect in either HASM or A549 cells. The COX 2:COX 1 selectivity ratio (COX 2 IC50/COX I IC50) was <0.0001 for nimesulide, 0.001 for NS398, 0.03 for flurbiprofen and 1.9 for indomethacin. In conclusion the present study has shown that cyclo-oxygenase inhibitors have a range of selectivities for cyclo-oxygenase 1 and cyclo-oxygenase 2 in intact human airway cells. The relative cyclo-oxygenase 2 selectivity of N-(2-cyclohexyloxy-4-nitrophenyl)-methanesulphonamide and nimesulide may have implications for the treatment of asthma and other inflammatory pulmonary diseases. PMID:10780769

Range, S P; Pang, L; Holland, E; Knox, A J

2000-04-01

157

Lasiodin Inhibits Proliferation of Human Nasopharyngeal Carcinoma Cells by Simultaneous Modulation of the Apaf-1/Caspase, AKT/MAPK and COX-2/NF-?B Signaling Pathways  

PubMed Central

Rabdosia serra has been widely used for the treatment of the various human diseases. However, the antiproliferative effects and underlying mechanisms of the compounds in this herb remain largely unknown. In this study, an antiproliferative compound against human nasopharyngeal carcinoma (NPC) cells from Rabdosia serra was purified and identified as lasiodin (a diterpenoid). The treatment with lasiodin inhibited cell viability and migration. Lasiodin also mediated the cell morphology change and induced apoptosis in NPC cells. The treatment with lasiodin induced the Apaf-1 expression, triggered the cytochrome-C release, and stimulated the PARP, caspase-3 and caspase-9 cleavages, thereby activating the apoptotic pathways. The treatment with lasiodin also significantly inhibited the phosphorylations of the AKT, ERK1/2, p38 and JNK proteins. The pretreatment with the AKT or MAPK-selective inhibitors considerably blocked the lasiodin-mediated inhibition of cell proliferation. Moreover, the treatment with lasiodin inhibited the COX-2 expression, abrogated NF-?B binding to the COX-2 promoter, and promoted the NF-?B translocation from cell nuclei to cytosol. The pretreatment with a COX-2-selective inhibitor abrogated the lasiodin-induced inhibition of cell proliferation. These results indicated that lasiodin simultaneously activated the Apaf-1/caspase-dependent apoptotic pathways and suppressed the AKT/MAPK and COX-2/NF-?B signaling pathways. This study also suggested that lasiodin could be a promising natural compound for the prevention and treatment of NPC. PMID:24845412

Lin, Lianzhu; Deng, Wuguo; Tian, Yun; Chen, Wangbing; Wang, Jingshu; Fu, Lingyi; Shi, Dingbo; Zhao, Mouming; Luo, Wei

2014-01-01

158

The sphingosine kinase 1/sphingosine-1-phosphate pathway mediates COX-2 induction and PGE2 production in response to TNF-alpha.  

PubMed

In this study we addressed the role of sphingolipid metabolism in the inflammatory response. In a L929 fibroblast model, tumor necrosis factor-alpha (TNF) induced prostaglandin E2 (PGE2) production by 4 h and cyclooxygenase-2 (COX-2) induction as early as 2 h. This TNF-induced PGE2 production was inhibited by NS398, a COX-2 selective inhibitor. GC-MS analysis revealed that only COX-2-generated prostanoids were produced in response to TNF, thus providing further evidence of COX-2 selectivity. As sphingolipids have been implicated in mediating several actions of TNF, their role in COX-2 induction and PGE2 production was evaluated. Sphingosine-1-phosphate (S1P) induced both COX-2 and PGE2 in a dose-responsive manner with an apparent ED50 of 100-300 nM. The related sphingolipid sphingosine also induced PGE2, though with much less efficacy. TNF induced a 3.5-fold increase in sphingosine-1-phosphate levels at 10 min that rapidly returned to baseline by 40 min. Small interfering RNAs (siRNAs) directed against mouse SK1 decreased (typically by 80%) SK1 protein and inhibited TNF-induced SK activity. Treatment of cells with RNAi to SK1 but not SK2 almost completely abolished the ability of TNF to induce COX-2 or generate PGE2. By contrast, cells treated with RNAi to S1P lyase or S1P phosphatase enhanced COX-2 induction leading to enhanced generation of PGE2. Treatment with SK1 RNAi also abolished the effects of exogenous sphingosine and ceramide on PGE2, revealing that the action of sphingosine and ceramide are due to intracellular metabolism into S1P. Collectively, these results provide novel evidence that SK1 and S1P are necessary for TNF to induce COX-2 and PGE2 production. Based on these findings, this study indicates that SK1 and S1P could be implicated in pathological inflammatory disorders and cancer. PMID:12890694

Pettus, Benjamin J; Bielawski, Jacek; Porcelli, Anna M; Reames, Davis L; Johnson, Korey R; Morrow, Jason; Chalfant, Charles E; Obeid, Lina M; Hannun, Yusuf A

2003-08-01

159

Modulation of COX2 expression by statins in human monocytic cells  

Microsoft Academic Search

Macrophage cyclooxygenase-2 (COX-2) plays an important role in prostaglandin E2 and throm- boxane A2 production. Statins are inhibitors of HMG CoA (3-Hydroxy-3-methylglutaryl coenzyme A) reduc- tases and cholesterol synthesis, which block the expres- sion of several inflammatory proteins independent of their capacity to lower endogenous cholesterol. In the present study, we investigated the effect of simvastatin and mevastatin on COX-2

Aida Habib; Ishraq Shamseddeen; Mona S. Nasrallah; Tania Abi Antoun; Georges Nemer; Jacques Bertoglio; Rami Badreddine; Kamal F. Badr

2007-01-01

160

Molecular Dynamics Simulations of Arachidonic Acid-Derived Pentadienyl Radical Intermediate Complexes with COX-1 and COX-2  

PubMed Central

The two cyclooxygenase enzymes, COX-1 and COX-2, are responsible for the committed step in prostaglandin biosynthesis, and are the targets of the non-steroidal anti-inflammatory drugs aspirin, ibuprofen and the COX-2 selective inhibitors, Celebrex™, Vioxx™ and Bextra™. The enzymes are remarkable in that they catalyze two dioxygenations and two cyclizations of the native substrate, arachidonic acid, with near absolute regio- and stereoselectivity. Several theories have been advanced to explain the nature of enzymatic control over this series of reactions, including suggestions of steric shielding and oxygen channeling. As proposed here, selective radical trapping and spin localization in the substrate-derived pentadienyl radical intermediate can also be envisioned. Herein we describe the results of explicit, 10 ns molecular dynamics simulations of both COX-1 and COX-2 with the substrate-derived pentadienyl radical intermediate bound in the active site. The enzymes’ influence on the conformation of the pentadienyl radical was investigated, along with the accessible space above and below the radical plane, and the width of several channels to the active site that could function as access routes for molecular oxygen. Additional simulations demonstrated the extent of molecular oxygen mobility within the active site. The results suggest that spin localization is unlikely to play a role in enzymatic control of this reaction. Instead, a combination of oxygen channeling, steric shielding and selective radical trapping appears to be responsible. This work adds a dynamic perspective to the strong foundation of static structural data available for these enzymes. PMID:16519515

Furse, Kristina E.; Pratt, Derek A.; Schneider, Claus; Brash, Alan R.; Porter, Ned A.; Lybrand, Terry P.

2008-01-01

161

Prostaglandin-mediated control of rat brain kynurenic acid synthesis--opposite actions by COX-1 and COX-2 isoforms.  

PubMed

Kynurenic acid (KYNA), an endogenous glutamate-receptor antagonist preferentially blocking NMDA-receptors, has analgesic properties and has also been implicated in the pathophysiology of schizophrenia. Recently, the non-steroid anti-inflammatory drug (NSAID) diclofenac was found to increase rat brain KYNA. Here, we analyze whether cyclooxygenase (COX)-1 or COX-2 modulate the levels of rat brain KYNA. The non-selective COX-inhibitor diclofenac (50 mg/kg, i.p.) or indomethacin (50 mg/kg, i.p.), a non-selective inhibitor with a preferential selectivity for COX-1, produced an elevation in brain KYNA. In contrast, the COX-2 selective inhibitors parecoxib (25 mg/kg, i.p.) or meloxicam (5 mg/kg, i.p.) decreased brain KYNA. Both elevation and lowering of brain KYNA by indomethacin or parecoxib, respectively, were prevented by the prostaglandin E1/E2 agonist misoprostol (1 mg/kg, s.c.). It is proposed that increased brain KYNA formation induced by NSAIDs displaying an inhibitory action on COX-1 contribute to their analgesic efficacy as well as to their psychiatric side effects. PMID:15517427

Schwieler, L; Erhardt, S; Erhardt, C; Engberg, G

2005-07-01

162

Staurosporine synergistically potentiates the deoxycholate?mediated induction of COX?2 expression  

PubMed Central

Abstract Colorectal cancer is a major cause of cancer?related death in western countries, and thus there is an urgent need to elucidate the mechanism of colorectal tumorigenesis. A diet that is rich in fat increases the risk of colorectal tumorigenesis. Bile acids, which are secreted in response to the ingestion of fat, have been shown to increase the risk of colorectal tumors. The expression of cyclooxygenase (COX)?2, an inducible isozyme of cyclooxygenase, is induced by bile acids and correlates with the incidence and progression of cancers. In this study, we investigated the signal transduction pathways involved in the bile?acid?mediated induction of COX?2 expression. We found that staurosporine (sts), a potent protein kinase C (PKC) inhibitor, synergistically potentiated the deoxycholate?mediated induction of COX?2 expression. Sts did not increase the stabilization of COX?2 mRNA. The sts? and deoxycholate?mediated synergistic induction of COX?2 expression was suppressed by a membrane?permeable Ca2+ chelator, a phosphoinositide 3?kinase inhibitor, a nuclear factor??B pathway inhibitor, and inhibitors of canonical and stress?inducible mitogen?activated protein kinase pathways. Inhibition was also observed using PKC inhibitors, suggesting the involvement of certain PKC isozymes (?, ?, ?, ?, or ?). Our results indicate that sts exerts its potentiating effects via the phosphorylation of p38. However, the effects of anisomycin did not mimic those of sts, indicating that although p38 activation is required, it does not enhance deoxycholate?induced COX?2 expression. We conclude that staurosporine synergistically enhances deoxycholate?induced COX?2 expression in RCM?1 colon cancer cells. PMID:25168879

Saeki, Tohru; Inui, Haruka; Fujioka, Saya; Fukuda, Suguru; Nomura, Ayumi; Nakamura, Yasushi; Park, Eun Young; Sato, Kenji; Kanamoto, Ryuhei

2014-01-01

163

Clinical pharmacology of lumiracoxib: a selective cyclo-oxygenase-2 inhibitor.  

PubMed

Lumiracoxib (Prexige) is a selective cyclo-oxygenase (COX)-2 inhibitor developed for the treatment of osteoarthritis, rheumatoid arthritis and acute pain. Lumiracoxib possesses a carboxylic acid group that makes it weakly acidic (acid dissociation constant [pKa] 4.7), distinguishing it from other selective COX-2 inhibitors. Lumiracoxib has good oral bioavailability (74%). It is rapidly absorbed, reaching maximum plasma concentrations 2 hours after dosing, and is highly plasma protein bound. Lumiracoxib has a short elimination half-life from plasma (mean 4 hours) and demonstrates dose-proportional plasma pharmacokinetics with no accumulation during multiple dosing. In patients with rheumatoid arthritis, peak lumiracoxib synovial fluid concentrations occur 3-4 hours later than in plasma and exceed plasma concentrations from 5 hours after dosing to the end of the 24-hour dosing interval. These data suggest that lumiracoxib may be associated with reduced systemic exposure, while still reaching sites where COX-2 inhibition is required for pain relief. Lumiracoxib is metabolised extensively prior to excretion, with only a small amount excreted unchanged in urine or faeces. Lumiracoxib and its metabolites are excreted via renal and faecal routes in approximately equal amounts. The major metabolic pathways identified involve oxidation of the 5-methyl group of lumiracoxib and/or hydroxylation of its dihaloaromatic ring. Major metabolites of lumiracoxib in plasma are the 5-carboxy, 4'-hydroxy and 4'-hydroxy-5-carboxy derivatives, of which only the 4'-hydroxy derivative is active and COX-2 selective. In vitro, the major oxidative pathways are catalysed primarily by cytochrome P450 (CYP) 2C9 with very minor contribution from CYP1A2 and CYP2C19. However, in patients genotyped as poor CYP2C9 metabolisers, exposure to lumiracoxib (area under the plasma concentration-time curve) is not significantly increased compared with control subjects, indicating no requirement for adjustment of lumiracoxib dose in these subjects. Lumiracoxib is selective for COX-2 compared with COX-1 in the human whole blood assay with a ratio of 515 : 1 in healthy subjects and in patients with osteoarthritis or rheumatoid arthritis. COX-2 selectivity was confirmed by a lack of inhibition of arachidonic acid and collagen-induced platelet aggregation. COX-2 selectivity of lumiracoxib is associated with a reduced incidence of gastroduodenal erosions compared with naproxen and a lack of effect on both small and large bowel permeability. Lumiracoxib does not exhibit any clinically meaningful interactions with a range of commonly used medications including aspirin (acetylsalicylic acid), fluconazole, an ethinylestradiol- and levonorgestrel-containing oral contraceptive, omeprazole, the antacid Maalox, methotrexate and warfarin (although, as in common practice, routine monitoring of coagulation is recommended when lumiracoxib is co-administered with warfarin). As such, dose adjustments are not required when co-administering these agents with lumiracoxib. In addition, moderate hepatic impairment and mild to moderate renal impairment do not appear to influence lumiracoxib exposure. PMID:16372823

Rordorf, Christiane M; Choi, Les; Marshall, Paul; Mangold, James B

2005-01-01

164

Design, synthesis, and structure-activity relationship studies of 3,4,6-triphenylpyran-2-ones as selective cyclooxygenase-2 inhibitors.  

PubMed

A group of regioisomeric 3,4,6-triphenylpyran-2-ones with a MeSO(2) pharmacophore at the para-position of either a C-3 phenyl or a C-4 phenyl substituent on the central six-membered pyran-2-one ring were prepared and evaluated in vitro for their abilities to inhibit the isozymes COX-1 and COX-2. Structure-activity relationship (SAR) data, acquired by substituent modification at the para-position of the C-6 phenyl ring attached to the central pyranone, showed that 6-(4-methoxyphenyl)-3-(4-methanesulfonylphenyl)-4-phenylpyran-2-one (12e) was the most potent and selective COX-2 inhibitor (COX-2 IC(50) = 0.02 microM; COX-1 IC(50) > 100 microM) with a high COX-2 selectivity index (SI > 5000) relative to the reference drugs celecoxib (COX-2 IC(50) = 0.07 microM; SI = 474) and rofecoxib (COX-2 IC(50) = 0.50 microM; SI > 200). 6-(4-Methoxyphenyl)-3-(4-methanesulfonylphenyl)-4-phenylpyran-2-one (12e) was a more potent oral antiinflammatory agent (ID(50) = 5.6 mg/kg) than celecoxib (ID(50) = 10.8 mg/kg) in a carrageenan-induced rat paw edema assay. In a 4% NaCl-induced abdominal constriction assay, a 5 mg/kg oral dose of 12e exhibited good analgesic activity at different time intervals producing 37.5 and 69% inhibition of writhing at 30 and 60 min, respectively. In contrast, the corresponding 6-(4-methoxyphenyl)-4-(4-methanesulfonylphenyl)-3-phenylpyran-2-one regiosiomer (12o) was a less potent and selective COX-2 inhibitor (COX-2 IC(50) = 0.45 microM; SI = 70). A molecular modeling study for 12e indicated that the p-OMe substituent on the C-6 phenyl ring interacts with the COX-2 binding site amino acids Ile(345), Val(349), Leu(359), Leu(531), and Met(535) and that the OMe substituent may be responsible for proper orientation of the C-3 p-SO(2)Me-phenyl ring within the COX-2 secondary pocket (Gln(192), Arg(513), and Phe(518)). These results show that the COX-2 selectivity and potency of 3,4,6-triphenylpyranone regioisomers can be modulated by appropriate placement of the p-SO(2)Me pharmacophore on either the C-3 or C-4 phenyl moiety. In addition, electronic properties at the para-position of a C-6 phenyl substituent on the central pyranone ring govern COX-2 inhibitory potency and selectivity by controlling the orientation of the p-SO(2)Me pharmacophore within the COX-2 secondary pocket. PMID:15267236

Rao, P N Praveen; Uddin, Md Jashim; Knaus, Edward E

2004-07-29

165

Design, synthesis, and biological evaluation of linear 1-(4-, 3- or 2-methylsulfonylphenyl)-2-phenylacetylenes: a novel class of cyclooxygenase-2 inhibitors.  

PubMed

A group of regioisomeric 1-(methylsulfonylphenyl)-2-phenylacetylenes possessing a COX-2 SO(2)Me pharmacophore at the para-, meta- or ortho-position of the C-1 phenyl ring, in conjunction with a C-2 phenyl or substituted-phenyl ring substituent (3-F, 3-OMe, 3-OH, 3-OAc, 4-Me), were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. These target linear 1,2-diarylacetylenes were synthesized via a palladium-catalyzed Sonogashira cross-coupling reaction followed by oxidation of the respective 1-(methylthiophenyl)-2-phenylacetylene intermediate. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 1-(3-methylsulfonylphenyl)-2-(4-methylphenyl)acetylene (12d) as a potent COX-2 inhibitor (IC(50) = 0.32 microM) with a high COX-2 selectivity index (SI > 320) comparable to the reference compound rofecoxib (COX-2 IC(50) = 0.50 microM; COX-2 SI > 200). A molecular modeling study where (12d) was docked in the binding site of COX-2 showed that the MeSO(2) COX-2 pharmacophore was positioned in the vicinity of the secondary COX-2 binding site near Val(523). The 1-(4-methylsulfonylphenyl)-2-(3-acetoxyphenyl)acetylene (11f, COX-1 IC(50) = 1.00 microM; COX-2 IC(50) = 0.06 microM; COX-2 SI = 16.7) and 1-(3-methylsulfonylphenyl)-2-(3-acetoxyphenyl)acetylene (12f, COX-1 IC(50) = 6.5 microM; COX-2 IC(50) = 0.05 microM; COX-2 SI = 130) regioisomers exhibited comparable COX-2 inhibition, and moderately lower selective COX-2 selectivity, relative to the reference drug celecoxib (COX-1 IC(50) = 33.1 microM; COX-2 IC(50) = 0.07 microM; COX-2 SI = 472). The most potent anti-inflammatory agent 1-(3-methylsulfonylphenyl)-2-(4-methylphenyl)acetylene (12d) exhibited moderate oral anti-inflammatory activity (ED(50)= 129 mg/kg) at 3 h postdrug administration relative to the reference drug celecoxib (ED(50) = 10.8 mg/kg) in a carrageenan-induced rat paw edema assay. The structure-activity data acquired indicate that the acetylene moiety constitutes a suitable scaffold (template) to design novel acyclic 1,2-diarylacetylenes with selective COX-2, or dual COX-1/COX-2, inhibitory activities. PMID:16099663

Chen, Qiao-Hong; Rao, P N Praveen; Knaus, Edward E

2005-12-01

166

Molecular determinants for the selective inhibition of cyclooxygenase-2 by lumiracoxib.  

PubMed

Lumiracoxib is the first example of a marketed COX-2 inhibitor of the arylacetic acid class, and it is reported to be the most selective COXIB in vivo. However, the molecular basis of its COX-2 inhibition has not been completely defined. Using standard assays, lumiracoxib was found to be a poor inhibitor of purified ovine COX-1 and a relatively weak inhibitor of purified human COX-2. The extent of COX-2 inhibition plateaued at around 50% and suggested that the inhibitor may be reversibly bound to the enzyme. Kinetic studies with lumiracoxib demonstrated that it was a time-dependent and slowly reversible inhibitor of human COX-2 that exhibited at least two binding steps during inhibition. Derivatives of lumiracoxib were synthesized with or without the methyl group on the phenylacetic acid ring and with various substitutions on the lower aniline ring. Inhibition studies demonstrated that the methyl group on the phenylacetic acid ring is required for COX-2 selectivity. The chemical identity and position of the substituents on the lower aniline ring were important in determining the potency and extent of COX inhibition as well as COX-2 selectivity. Mutation of Ser-530 to Ala or Val-349 to Ala or Leu abolished the potent inhibition observed with wild-type human COX-2 and key lumiracoxib analogs. Interestingly, a Val-349 to Ile mutant was inhibited with equal potency to human COX-2 with 2,6-dichloro-, 2,6-dimethyl-, or 2-chloro-6-methyl-substituted inhibitors and, in the case of lumiracoxib, actually showed an increase in potency. Taken together with a recent crystal structure of a lumiracoxib-COX-2 complex, the kinetic analyses presented herein of the inhibition of mutant COX-2s by lumiracoxib allows the definition of the molecular basis of COX-2 inhibition. PMID:17434872

Blobaum, Anna L; Marnett, Lawrence J

2007-06-01

167

A quantitative analysis of kinase inhibitor selectivity  

Microsoft Academic Search

Kinase inhibitors are a new class of therapeutics with a propensity to inhibit multiple targets. The biological consequences of multi-kinase activity are poorly defined, and an important step toward understanding the relationship between selectivity, efficacy and safety is the exploration of how inhibitors interact with the human kinome. We present interaction maps for 38 kinase inhibitors across a panel of

Mazen W Karaman; Sanna Herrgard; Daniel K Treiber; Paul Gallant; Corey E Atteridge; Brian T Campbell; Katrina W Chan; Pietro Ciceri; Mindy I Davis; Philip T Edeen; Raffaella Faraoni; Mark Floyd; Jeremy P Hunt; Daniel J Lockhart; Zdravko V Milanov; Michael J Morrison; Gabriel Pallares; Hitesh K Patel; Stephanie Pritchard; Lisa M Wodicka; Patrick P Zarrinkar

2008-01-01

168

BMP9 and COX-2 form an important regulatory loop in BMP9-induced osteogenic differentiation of mesenchymal stem cells.  

PubMed

Mesenchymal stem cells (MSCs) can self-renew and differentiate into osteogenic, chondrogenic, adipogenic and myogenic lineages. It's reported that bone morphogenetic protein 9 (BMP9) is one of the most potent osteogenic BMPs to initiate the commitment of MSCs to osteoblast lineage. Cyclooxygenase-2 (COX-2) is critical for bone fracture healing and osteogenic differentiation in MSCs. However, the relationship between COX-2 and BMP9 in osteogenesis remains unknown. Herein, we investigate the role of COX-2 in BMP9-induced osteogenesis in MSCs. We demonstrate that COX-2 is up-regulated as a target of BMP9 in MSCs. Both COX-2 inhibitor (NS-398) and COX-2 knockdown siRNAs can effectively decrease alkaline phosphatase (ALP) activities induced by BMP9 in MSCs. NS-398 also down-regulates BMP9-induced expression of osteopontin and osteocalcin, so does the matrix mineralization. The in vivo studies indicate that knockdown of COX-2 attenuates BMP9-induced ectopic bone formation. In perinatal limb culture assay, NS-398 is shown to reduce the hypertropic chondrocyte zone and ossification induced by BMP9. Mechanistically, knockdown of COX-2 significantly inhibits the BMP9 up-regulated expression of Runx2 and Dlx-5 in MSCs, which can be rescued by exogenous expression of COX-2. Furthermore, knockdown of COX-2 apparently reduces BMP9 induced BMPR-Smad reporter activity, the phosphorylation of Smad1/5/8, and the expression of Smad6 and Smad7 in MSCs. NS-398 blocks the expression of BMP9 mediated by BMP9 recombinant adenovirus. Taken together, our findings suggest that COX-2 plays an important role in BMP9 induced osteogenic differentiation in MSCs; BMP9 and COX-2 may form an important regulatory loop to orchestrate the osteogenic differentiation in MSCs. PMID:23981660

Wang, Jin-Hua; Liu, Ying-Zi; Yin, Liang-Jun; Chen, Liang; Huang, Jun; Liu, Yang; Zhang, Ran-Xi; Zhou, Long-Yang; Yang, Qiu-Jun; Luo, Jin-Yong; Zuo, Guo-wei; Deng, Zhong-Liang; He, Bai-Cheng

2013-11-01

169

Cyclooxygenase-2 inhibitors. 1,5-diarylpyrrol-3-acetic esters with enhanced inhibitory activity toward cyclooxygenase-2 and improved cyclooxygenase-2/cyclooxygenase-1 selectivity.  

PubMed

The important role of cyclooxygenase-2 (COX-2) in the pathogenesis of inflammation and side effect limitations of current COX-2 inhibitor drugs illustrates a need for the design of new compounds based on alternative structural templates. We previously reported a set of substituted 1,5-diarylpyrrole derivatives, along with their inhibitory activity toward COX enzymes. Several compounds proved to be highly selective COX-2 inhibitors and their affinity data were rationalized through docking simulations. In this paper, we describe the synthesis of new 1,5-diarylpyrrole derivatives that were assayed for their in vitro inhibitory effects toward COX isozymes. Among them, the ethyl-2-methyl-5-[4-(methylsulfonyl)phenyl]-1-[3-fluorophenyl]-1H-pyrrol-3-acetate (1d), which was the most potent and COX-2 selective compound, also showed a very interesting in vivo anti-inflammatory and analgesic activity, laying the foundations for developing new lead compounds that could be effective agents in the armamentarium for the management of inflammation and pain. PMID:17915854

Biava, Mariangela; Porretta, Giulio Cesare; Poce, Giovanna; Supino, Sibilla; Forli, Stefano; Rovini, Michele; Cappelli, Andrea; Manetti, Fabrizio; Botta, Maurizio; Sautebin, Lidia; Rossi, Antonietta; Pergola, Carlo; Ghelardini, Carla; Vivoli, Elisa; Makovec, Francesco; Anzellotti, Paola; Patrignani, Paola; Anzini, Maurizio

2007-11-01

170

Synthesis and biological evaluation of new 4-carboxyl quinoline derivatives as cyclooxygenase-2 inhibitors.  

PubMed

A group of 4-carboxyl quinoline derivatives possessing a methylsulfonyl COX-2 pharmacophore at the para position of the C-2 phenyl ring were designed and synthesized as selective COX-2 inhibitors. In vitro COX-1/COX-2 structure-activity relationships were determined by varying the substituents on the C-7 and C-8 quinoline ring. Among the 4-carboxyl quinolines, 7,8,9,10-tetrahydro-2-(4-(methyl sulfonyl)phenyl)benzo[h]quinoline-4-carboxylic acid (9e) was identified as potent and high selective COX-2 inhibitor (COX-2 IC(50)=0.043microM; selectivity index>513) that was more potent than the reference drug celecoxib (COX-2 IC(50)=0.060microM; SI=405). A molecular modeling study where 9e was docked in the binding site of COX-2 showed that the p-MeSO(2) substituent on the C-2 phenyl ring is oriented in the vicinity of the COX-2 secondary pocket (Arg513, Phe518 and Val523) and the carboxyl group can interact with Arg120. The structure activity data acquired indicate that the presence of lipophilic substituents on the C-7 and C-8 quinoline ring is important for COX-2 inhibitory activity. PMID:19560931

Zarghi, Afshin; Ghodsi, Razieh; Azizi, Ebrahim; Daraie, Bahram; Hedayati, Mehdi; Dadrass, Orkideh G

2009-07-15

171

Cyclooxygenase-1-Selective Inhibitors Based on the (E)-2?-Des-methyl-sulindac Sulfide Scaffold  

PubMed Central

Prostaglandins (PGs) are powerful lipid mediators in many physiological and pathophysiological responses. They are produced by oxidation of arachidonic acid (AA) by cyclooxygenases (COX-1 and COX-2) followed by metabolism of endoperoxide intermediates by terminal PG synthases. PG biosynthesis is inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs). Specific inhibition of COX-2 has been extensively investigated, but relatively few COX-1-selective inhibitors have been described. Recent reports of a possible contribution of COX-1 in analgesia, neuroinflammation, or carcinogenesis suggest that COX-1 is a potential therapeutic target. We designed, synthesized, and evaluated a series of (E)-2?-des-methyl-sulindac sulfide (E-DMSS) analogues for inhibition of COX-1. Several potent and selective inhibitors were discovered, and the most promising compounds were active against COX-1 in intact ovarian carcinoma cells (OVCAR-3). The compounds inhibited tumor cell proliferation but only at concentrations >100-fold higher than the concentrations that inhibit COX-1 activity. E-DMSS analogues may be useful probes of COX-1 biology in vivo and promising leads for COX-1-targeted therapeutic agents. PMID:22263894

2012-01-01

172

Design, synthesis, and biological evaluation of 1,3-diarylprop-2-en-1-ones : a novel class of cyclooxygenase-2 inhibitors.  

PubMed

A group of regioisomeric (E)-1,3-diarylprop-2-en-1-one derivatives possessing a COX-2 SO2Me pharmacophore at the para position of the C-1 or C-3 phenyl ring, in conjunction with a C-3 or C-1 phenyl (4-H) or substituted-phenyl ring (4-F, 4-OMe and 4-Me), were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. These target (E)-1,3-diarylprop-2-en-1-ones were synthesized via a Claisen-Schmidt condensation reaction. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified (E)-1-(4-methanesulfonylphenyl)-3-(4-methylphenyl)prop-2-en-1-one (9f) as a potent COX-2 inhibitor (IC50=0.3 microM) with a high COX-2 selectivity index (SI=106) comparable to that of the reference drug rofecoxib (COX-2 IC50=0.5 microM; COX-2 SI>200). A molecular modeling study where 9f was docked in the binding site of COX-2 showed that the para-SO2Me substituent on the C-1 phenyl ring is oriented in the vicinity of the secondary COX-2 binding site near Val523. The structure-activity data acquired indicate that the propenone moiety constitutes a suitable scaffold to design novel acyclic 1,3-diarylprop-2-en-1-ones with selective COX-2 inhibitory activity. PMID:16356730

Zarghi, Afshin; Arfaee, Sara; Rao, P N Praveen; Knaus, Edward E

2006-04-15

173

COX2-derived primary and cyclopentenone prostaglandins are increased after asphyxial cardiac arrest  

PubMed Central

Background Cyclopentenone prostaglandins have been identified as potential neurotoxic agents in the setting of hypoxia-ischemia. Cyclooxygenase-2 (COX-2), the upstream enzyme responsible for prostaglandin production is upregulated following hypoxic-ischemic brain injury. However, the temporal production and concentration of cyclopentenone prostaglandins has not been described following global brain ischemia. Methods Global brain ischemia was induced in rats by asphyxial cardiac arrest (ACA) followed by resuscitation. Rats were sacrificed between 24 hours and 7 days following resuscitation and their brains removed. Western blot, immunohistochemistry, and mass spectroscopy were performed. A cohort of rats was pretreated with the COX-2 inhibitor SC58125. Results COX-2 is induced in hippocampus at 24 hours following ACA. Multiple prostaglandins, including cyclopentenone prostaglandin species, are increased in hippocampus as 24 hours following ACA. Prostaglandin and cyclopentenone prostaglandin concentrations are returned to baseline at 3 and 7 days post-ischemia. The COX-2 inhibitor SC58125 completely abrogates the post-ischemic increase in prostaglandins and cyclopentenone prostaglandins. Conclusions Prostaglandins, including cyclopentenone prostaglandins, are increased in ischemic brain, peak at 24 hours and can be attenuated by the COX-2 inhibitor SC58125. These data establish the presence of potentially neurotoxic cyclopentenone prostaglandins in post-ischemic brains, thus identifying a target and therapeutic window for neuroprotective therapies. PMID:23624225

Liu, Hao; Rose, Marie E.; Miller, Tricia M.; Li, Wenjin; Shinde, Sunita N.; Pickrell, Alicia M.; Poloyac, Samuel M.; Graham, Steven H.

2013-01-01

174

Regulated Expression of PTPRJ by COX-2/PGE2 Axis in Endothelial Cells  

PubMed Central

Background This study was designed to examine a novel role of COX-2/PGE2 signaling as a regulator of PTPRJ expression in endothelial cells. Methods A bioinformatics analysis of a whole genome array was carried out to search for regulators of PTPRJ expression in endothelial cells. PTPRJ expression was also measured in endothelial cells derived from a balloon injury-induced neointimal hyperplasia model in male New Zealand Rabbits. Changes in PTPRJ expression in HUVEC cells was examined by RT-PCR and western blotting after transfection of COX-2 plasmids or treatment with varying concentrations of a COX-2 inhibitor. Results A significant correlation was identified between COX-2 and PTPRJ in GSE39264 (Pearson correlation coefficient ?=??0.87; n?=?22; P<0.01, two-tailed). PTPRJ expression was reduced during the progression of neointimal hyperplasia after balloon injury, which correlated with an increase in COX-2 expression. In HUVECs, after transfection with 1 µg/ml, 0.5 µg/ml, or 0.25 µg/ml COX-2 plasmids, PTPRJ protein expression was reduced to 0.60- (±0.08), 0.75- (±0.09), and 0.88- (±0.04) fold, respectively, while mRNA expression was reduced to 0.15- (±0.03), 0.26- (±0.05), and 0.47- (±0.09) fold, respectively. After treatment of HUVECs with 10 µmol/L or 20 µmol/L celecoxib, the reduction in PTPRJ expression induced by COX-2 over-expression was not only rescued but in fact increased by 2.05-fold (±0.28) and 3.34-fold (±0.37), respectively, compared with control. Conclusions Our results suggest that COX-2/PGE2 signaling may function as a negative regulator of PTPRJ expression in endothelial cells both in vivo and vitro. PMID:25532119

Jin, Xinxin; Wang, Bin; Yan, Hongbo; Chen, Xi; Lai, Xiaowei; Zhang, Li; Zhang, Xiaohua; Li, Zhaoshen

2014-01-01

175

Do selective cyclo-oxygenase-2 inhibitors and traditional non-steroidal anti-inflammatory drugs increase the risk of atherothrombosis? Meta-analysis of randomised trials  

Microsoft Academic Search

Objective To assess the effects of selective cyclo-oxygenase-2 (COX 2) inhibitors and traditional non-steroidal anti-inflammatory drugs (NSAIDs) on the risk of vascular events. Design Meta-analysis of published and unpublished tabular data from randomised trials, with indirect estimation of the effects of traditional NSAIDs. Data sources Medline and Embase (January 1966 to April 2005); Food and Drug Administration records; and data

Patricia M Kearney; Colin Baigent; Jon Godwin; Heather Halls; Jonathan R Emberson; Carlo Patrono

2006-01-01

176

Monocytes stimulate COX2 expression in pancreatic cancer cells  

Microsoft Academic Search

COX-2 is an enzyme that modulates human pancreatic cancer (PaCa) cell survival, proliferation, and tumor metastasis. 60–80% of human PaCa express COX-2. However, the regulation of COX-2 expression in PaCa cells is not clear. We hypothesize that inflammatory cell infiltrate—namely monocytes\\/macrophages found commonly in PaCa—regulates the expression and activity of COX-2. The human histiocytic lymphoma cell line U937 was terminally

G. Eibl; Y. Okada; H. A. Reber; T. E. Rix; J. P. Duffy; O. J. Hines

2003-01-01

177

Up-regulation of p53 and mitochondrial signaling pathway in apoptosis by a combination of COX-2 inhibitor, Celecoxib and Dolastatin 15, a marine mollusk linear peptide in experimental colon carcinogenesis.  

PubMed

Programmed cell death, also known as apoptosis, is an active process occurring in eukaryotic cells and it depends on various sets of pro and anti-apoptotic proteins. Chemoprevention of colorectal cancer can be achieved by inducing apoptosis using synthetic compound, Celecoxib and natural peptide, Dolastatin 15 in an effective manner. But the apoptotic signaling by these two drugs remain unclear. The present study was thus focused on the role of Bcl2 family of proteins and their interplay with p53 in rats during the chemoprevention by these two drugs. After treatment for 6 wk with 1, 2-dimethylhydrazine (DMH), animals showed a marked occurrence of multiple plaque lesions. However, a simultaneous treatment with Celecoxib and Dolastatin 15 decreases such number to a significant level. DMH treatment also decreases the number of apoptotic cells in the colonic enterocytes which were corrected to the normal level by Celecoxib and Dolastatin 15. An increased expression of Bcl2 while other proteins like Bax, Apaf-1, cyt c, and caspases in the apoptotic pathway, and the tumor suppressor proteins, p53 and p21 get down-regulated after DMH treatment which were reverted back to normal with Celecoxib and Dolastatin 15. Also, cells having high mitochondrial membrane potential had been seen to increase to significant levels which were reduced after the administration of these anti-inflammatory drugs. In silico molecular docking studies also showed that Dolastatin 15 and Celecoxib may bind to the active site pocket of Bcl2 , thus revealing the direct target of Dolastatin 15 and Celecoxib apart from binding to COX-2. PMID:22623379

Piplani, Honit; Vaish, Vivek; Rana, Chandan; Sanyal, Sankar N

2013-11-01

178

Non-COX-2 targets and cancer: Expanding the molecular target repertoire of chemoprevention  

Microsoft Academic Search

Chemoprevention represents a highly promising approach for the control of cancer. That nonsteroidal anti-inflammatory drugs (NSAIDs) prevent colon and other cancers has led to novel approaches to cancer prevention. The known inhibitory effect of NSAIDs on the eicosanoid pathway prompted mechanistic and drug development work focusing on cyclooxygenase (COX), culminating in clinical trials of cyclooxygenase 2 (COX-2) inhibitors for cancer

Khosrow Kashfi; Basil Rigas

2005-01-01

179

A high throughput screen identifies potent and selective inhibitors to human epithelial 15-lipoxygenase-2.  

PubMed

Lipoxygenase (LOX) enzymes catalyze the hydroperoxidation of arachidonic acid and other polyunsaturated fatty acids to hydroxyeicosatetraenoic acids with varying positional specificity to yield important biological signaling molecules. Human epithelial 15-lipoxygenase-2 (15-LOX-2) is a highly specific LOX isozyme that is expressed in epithelial tissue and whose activity has been correlated with suppression of tumor growth in prostate and other epithelial derived cancers. Despite the potential utility of an inhibitor to probe the specific role of 15-LOX-2 in tumor progression, no such potent/specific 15-LOX-2 inhibitors have been reported to date. This study employs high throughput screening to identify two novel, specific 15-LOX-2 inhibitors. MLS000545091 is a mixed-type inhibitor of 15-LOX-2 with a Ki of 0.9+/-0.4 µM and has a 20-fold selectivity over 5-LOX, 12-LOX, 15-LOX-1, COX-1, and COX-2. MLS000536924 is a competitive inhibitor with a Ki of 2.5+/-0.5 µM and also possesses 20-fold selectivity toward 15-LOX-2 over the other oxygenases, listed above. Finally, neither compound possesses reductive activity towards the active-site ferrous ion. PMID:25111178

Jameson, J Brian; Kantz, Auric; Schultz, Lena; Kalyanaraman, Chakrapani; Jacobson, Matthew P; Maloney, David J; Jadhav, Ajit; Simeonov, Anton; Holman, Theodore R

2014-01-01

180

A High Throughput Screen Identifies Potent and Selective Inhibitors to Human Epithelial 15-Lipoxygenase-2  

PubMed Central

Lipoxygenase (LOX) enzymes catalyze the hydroperoxidation of arachidonic acid and other polyunsaturated fatty acids to hydroxyeicosatetraenoic acids with varying positional specificity to yield important biological signaling molecules. Human epithelial 15­lipoxygenase­2 (15-LOX-2) is a highly specific LOX isozyme that is expressed in epithelial tissue and whose activity has been correlated with suppression of tumor growth in prostate and other epithelial derived cancers. Despite the potential utility of an inhibitor to probe the specific role of 15-LOX-2 in tumor progression, no such potent/specific 15­LOX­2 inhibitors have been reported to date. This study employs high throughput screening to identify two novel, specific 15­LOX­2 inhibitors. MLS000545091 is a mixed-type inhibitor of 15-LOX-2 with a Ki of 0.9+/?0.4 µM and has a 20-fold selectivity over 5-LOX, 12-LOX, 15-LOX-1, COX-1, and COX-2. MLS000536924 is a competitive inhibitor with a Ki of 2.5+/?0.5 µM and also possesses 20-fold selectivity toward 15-LOX-2 over the other oxygenases, listed above. Finally, neither compound possesses reductive activity towards the active-site ferrous ion. PMID:25111178

Jameson, J. Brian; Kantz, Auric; Schultz, Lena; Kalyanaraman, Chakrapani; Jacobson, Matthew P.; Maloney, David J.; Jadhav, Ajit; Simeonov, Anton; Holman, Theodore R.

2014-01-01

181

Selective cyclooxygenase-2 silencing mediated by engineered E. coli and RNA interference induces anti-tumour effects in human colon cancer cells  

PubMed Central

Background: Cyclooxygenase-2 (COX-2) overexpression is strongly associated with colorectal tumourigenesis. It has been demonstrated that the chronic use of non-steroidal anti-inflammatory drugs (COX inhibitors) partially protects patients from colorectal cancer (CRC) development and progression but induces severe cardiovascular side effects. New strategies for selective COX-2 blockade are required. Methods: We developed an improved technique, based on RNA interference (RNAi), to gain a selective COX-2 silencing in CRC cells by a tumour-dependent expression of anti-COX-2 short-hairpin RNA (shCOX-2). Anti-COX-2 shRNA-expressing vectors were delivered in CRC cells (in vitro) and in colon tissues (ex vivo) using engineered Escherichia coli strains, capable of invading tumour cells (InvColi). Results: A highly tumour-dependent shCOX-2 expression and a significant COX-2 silencing were observed in CRC cells following InvColi strain infection. Cyclooxygenase-2 silencing was associated with a strong reduction in both proliferative and invasive behaviour of tumour cells. We also demonstrated a pivotal role of COX-2 overexpression for the survival of CRC cells after bacterial infection. Moreover, COX-2 silencing was achieved ex vivo by infecting colon tissue samples with InvColi strains, leading to anti-inflammatory and anti-tumour effects. Conclusion: Our RNAi/InvColi-mediated approach offers a promising tool for a highly selective COX-2 blockade in vitro and in vivo. PMID:20717114

Strillacci, A; Griffoni, C; Lazzarini, G; Valerii, M C; Di Molfetta, S; Rizzello, F; Campieri, M; Moyer, M P; Tomasi, V; Spisni, E

2010-01-01

182

ABT-963 [2-(3,4-difluoro-phenyl)-4-(3-hydroxy-3-methyl-butoxy)-5-(4-methanesulfonyl-phenyl)-2H-pyridazin-3-one], a highly potent and selective disubstituted pyridazinone cyclooxgenase-2 inhibitor.  

PubMed

Nonsteriodal anti-inflammatory drugs (NSAIDs) are efficacious for the treatment of pain associated with inflammatory disease. Clinical experience with marketed selective cyclooxygenase-2 (COX-2) inhibitors (celecoxib, rofecoxib, and valdecoxib) has confirmed the utility of these agents in the treatment of inflammatory pain with an improved gastrointestinal safety profile relative to NSAID comparators. These COX-2 inhibitors belong to the same structural class. Each contains a core heterocyclic ring with two appropriately substituted phenyl rings appended to adjacent atoms. Here, we report the identification of vicinally disubstituted pyridazinones as potent and selective COX-2 inhibitors. The lead compound in the series, ABT-963 [2-(3,4-difluoro-phenyl)-4-(3-hydroxy-3-methyl-butoxy)-5-(4-methanesulfonyl-phenyl)-2H-pyridazin-3-one], has excellent selectivity (ratio of 276, COX-2/COX-1) in human whole blood, improved aqueous solubility compared with celecoxib and rofecoxib, high oral anti-inflammatory potency in vivo, and gastric safety in the animal studies. After oral administration, ABT-963 reduced prostaglandin E2 production in the rat carrageenan air pouch model (ED50 of 0.4 mg/kg) and reduced the edema in the carrageenan induced paw edema model with an ED30 of 1.9 mg/kg. ABT-963 dose dependently reduced nociception in the carrageenan hyperalgesia model (ED50 of 3.1 mg/kg). After 14 days of dosing in the adjuvant arthritis model, ABT-963 had an ED(50) of 1.0 mg/kg in reducing the swelling of the hind paws. Magnetic resonance imaging examination of the diseased paws in the adjuvant model showed that ABT-963 significantly reduced bone loss and soft tissue destruction. ABT-963 is a highly selective COX-2 inhibitor that may have utility in the treatment of the pain and inflammation associated with arthritis. PMID:15277581

Harris, Richard R; Black, Lawrence; Surapaneni, Sekhar; Kolasa, Teodozyj; Majest, Sandra; Namovic, Marian T; Grayson, George; Komater, Victoria; Wilcox, Denise; King, Linda; Marsh, Kennan; Jarvis, Michael F; Nuss, Merrill; Nellans, Hugh; Pruesser, Lee; Reinhart, Glenn A; Cox, Bryan; Jacobson, Peer; Stewart, Andrew; Coghlan, Michael; Carter, George; Bell, Randy L

2004-12-01

183

Epithelial 11?-hydroxysteroid dehydrogenase type II deletion inhibits Apc+/min mouse tumorigenesis via COX-2 pathway inhibition and induction of G1 cell cycle arrest  

PubMed Central

Cyclooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) promotes colorectal tumorigenesis. Glucocorticoids are endogenous and potent COX-2 inhibitors, and their local actions are down-regulated by 11?–hydroxysteroid dehydrogenase type II (11ßHSD2)-mediated metabolism. We previously reported that 11ßHSD2 increased in human colonic and Apc+/min mouse intestinal adenomas and correlated with increased COX-2 expression and activity, and 11ßHSD2 inhibition suppressed the COX-2 pathway and decreased tumorigenesis. 11ßHSD2 is expressed in Apc+/min mouse intestinal adenoma stromal and epithelial cells. We generated Apc+/min mice with selective deletion of 11ßHSD2 in intestinal epithelial cells (Vil-HSD2-/- Apc+/min). 11ßHSD2 deletion in intestinal epithelia led to marked inhibition of Apc+/min mouse intestinal tumorigenesis. Immunostaining indicated decreased 11ßHSD2 and COX-2 expression in adenoma epithelia, while stromal COX-2 expression was intact in Vil-HSD2-/- Apc+/min mice. In Vil-HSD2-/- Apc+/min mouse intestinal adenomas, both p53 and p21 mRNA and protein levels were increased, with concomitant decrease in phosphorylation of retinoblastoma protein, indicating glucocorticoid-mediated G1 cell cycle arrest. Regulated in development and DNA damage responses 1 (REDD1), a novel stress-induced gene that inhibits mammalian target of rapamycin (mTOR) signaling pathway, was increased, while the mTOR signaling pathway was inhibited. Therefore, in Vil-HSD2-/- Apc+/min mice, epithelial cell 11ßHSD2 deficiency leads to inhibition of adenoma initiation and growth by attenuation of COX-2 expression, increased G1 cell cycle arrest and inhibition of mTOR signaling as a result of increased tumor intracellular active glucocorticoids. 11ßHSD2 inhibition may represent a novel approach for colorectal cancer chemoprevention by increasing tumor glucocorticoid activity, which in turn inhibits tumor growth by multiple pathways. PMID:23741059

Jiang, Li; Yang, Shilin; Yin, Huiyong; Fan, Xiaofeng; Wang, Suwan; Yao, Bing; Pozzi, Ambra; Chen, Xiaoping; Harris, Raymond C; Zhang, Ming-Zhi

2013-01-01

184

Molecular dynamics simulations of arachidonic acid-derived pentadienyl radical intermediate complexes with COX-1 and COX-2: insights into oxygenation regio- and stereoselectivity.  

PubMed

The two cyclooxygenase enzymes, COX-1 and COX-2, are responsible for the committed step in prostaglandin biosynthesis and are the targets of the nonsteroidal antiinflammatory drugs aspirin and ibuprofen and the COX-2 selective inhibitors, Celebrex, Vioxx, and Bextra. The enzymes are remarkable in that they catalyze two dioxygenations and two cyclizations of the native substrate, arachidonic acid, with near absolute regio- and stereoselectivity. Several theories have been advanced to explain the nature of enzymatic control over this series of reactions, including suggestions of steric shielding and oxygen channeling. As proposed here, selective radical trapping and spin localization in the substrate-derived pentadienyl radical intermediate can also be envisioned. Herein we describe the results of explicit, 10 ns molecular dynamics simulations of both COX-1 and COX-2 with the substrate-derived pentadienyl radical intermediate bound in the active site. The enzymes' influence on the conformation of the pentadienyl radical was investigated, along with the accessible space above and below the radical plane and the width of several channels to the active site that could function as access routes for molecular oxygen. Additional simulations demonstrated the extent of molecular oxygen mobility within the active site. The results suggest that spin localization is unlikely to play a role in enzymatic control of this reaction. Instead, a combination of oxygen channeling, steric shielding, and selective radical trapping appears to be responsible. This work adds a dynamic perspective to the strong foundation of static structural data available for these enzymes. PMID:16519515

Furse, Kristina E; Pratt, Derek A; Schneider, Claus; Brash, Alan R; Porter, Ned A; Lybrand, Terry P

2006-03-14

185

Celecoxib exerts antitumor effects in canine mammary tumor cells via COX?2?independent mechanisms.  

PubMed

Celecoxib plays antitumor roles via multiple mechanisms in a variety of human cancers. The aim of this study was to clarify the mechanism of action of celecoxib in canine mammary tumors. We examined the antitumor effects of celecoxib in AZACB canine mammary tumor cells expressing low levels of cyclooxygenase?2 (COX?2) to minimize the effect of COX?2 on its activity. Our data revealed that celecoxib inhibited cell proliferation mainly via COX?2?independent mechanisms. Specifically, celecoxib decreased the proportion of cells in S phase and increased G2/M arrest, which was associated with increased expression of the cyclin?dependent kinase inhibitors (CDKIs) p21 and p27. In addition, treatment with celecoxib downregulated COX?2 expression, and induced apoptosis via both the intrinsic and extrinsic pathways. These findings suggest that celecoxib might be a useful agent for the treatment of canine mammary tumors, regardless of COX?2 expression. In the future, it might be possible to use a combination of celecoxib and other antitumor agents to treat canine mammary tumors. PMID:25571853

Tamura, Dai; Saito, Teruyoshi; Murata, Kanae; Kawashima, Masafumi; Asano, Ryuji

2015-03-01

186

STIM1 overexpression promotes colorectal cancer progression, cell motility and COX-2 expression.  

PubMed

Tumor metastasis is the major cause of death among cancer patients, with >90% of cancer-related death attributable to the spreading of metastatic cells to secondary organs. Store-operated Ca(2+) entry (SOCE) is the predominant Ca(2+) entry mechanism in most cancer cells, and stromal interaction molecule 1 (STIM1) is the endoplasmic reticulum (ER) Ca(2+) sensor for store-operated channels. Here we reported that the STIM1 was overexpressed in colorectal cancer (CRC) patients. STIM1 overexpression in CRC was significantly associated with tumor size, depth of invasion, lymph node metastasis status and serum levels of carcinoembryonic antigen. Furthermore, ectopic expression of STIM1 promoted CRC cell motility, while depletion of STIM1 with short hairpin RNA inhibited CRC cell migration. Our data further suggested that STIM1 promoted CRC cell migration through increasing the expression of cyclooxygenase-2 (COX-2) and production of prostaglandin E2 (PGE2). Importantly, ectopically expressed COX-2 or exogenous PGE2 were able to rescue migration defect in STIM1 knockdown CRC cells, and inhibition of COX-2 with ibuprofen and indomethacin abrogated STIM1-mediated CRC cell motility. In short, our data provided clinicopathological significance for STIM1 and SOCE in CRC progression, and implicated a role for COX-2 in STIM1-mediated CRC metastasis. Our studies also suggested a new approach to inhibit STIM1-mediated metastasis with COX-2 inhibitors.Oncogene advance online publication, 10 November 2014; doi:10.1038/onc.2014.366. PMID:25381814

Wang, J-Y; Sun, J; Huang, M-Y; Wang, Y-S; Hou, M-F; Sun, Y; He, H; Krishna, N; Chiu, S-J; Lin, S; Yang, S; Chang, W-C

2014-11-10

187

Preclinical pharmacology profile of CS-706, a novel cyclooxygenase-2 selective inhibitor, with potent antinociceptive and anti-inflammatory effects.  

PubMed

We report here the preclinical anti-inflammatory profile of CS-706 [2-(4-ethoxyphenyl)-4-methyl-1-(4-sulfamoylphenyl)-1H-pyrrole], a novel cyclooxygenase-2 (COX-2) selective inhibitor. CS-706 selectively inhibited COX-2 in a human whole blood assay with an IC(50) of 0.31 microM, compared with an IC(50) of 2.2 microM for COX-1. The selectivity ratio of CS-706 was higher than those of the conventional non-steroidal anti-inflammatory drugs naproxen, indomethacin, and Diclofenac-Na, whereas it was lower than those of rofecoxib, valdecoxib and etoricoxib. It was similar to that of celecoxib. The pharmacokinetic profile of CS-706 showed rapid absorption and dose-proportional exposure after oral administration to rats. CS-706 inhibited prostaglandin E(2) production in inflamed tissue induced by yeast-injection in rats with potency similar to that of indomethacin. However, it inhibited gastric mucosal prostaglandin E(2) production in normal rats weakly compared with indomethacin. CS-706 ameliorated both yeast-induced inflammatory acute pain (ED(50)=0.0090 mg/kg) and adjuvant-induced chronic arthritic pain (ED(50)=0.30 mg/kg) in rats. CS-706 showed more potent antinociceptive activity than celecoxib and rofecoxib in these models. In an adjuvant-induced arthritic model in rats, CS-706 suppressed foot swelling prophylactically with an ID(50) of 0.10 mg/kg/day, and decreased foot swelling in the established arthritis therapeutically in a dose range of 0.040 to 1.0 mg/kg/day. Single administration of up to 100 mg/kg of CS-706 induced no significant gastric lesions in rats. In conclusion, CS-706 is a COX-2-selective inhibitor with a potent antinociceptive and anti-inflammatory activity and a gastric safety profile. PMID:17920584

Ushiyama, Shigeru; Yamada, Tomoko; Murakami, Yukiko; Kumakura, Sei-ichiro; Inoue, Shin-ichi; Suzuki, Keisuke; Nakao, Akira; Kawara, Akihiro; Kimura, Tomio

2008-01-01

188

Anti-inflammatory, cyclooxygenase (COX)-2, COX-1 inhibitory, and free radical scavenging effects of Rumex nepalensis.  

PubMed

Evaluation of the topical anti-inflammatory activity of chloroform and ethyl acetate extracts of RUMEX NEPALENSIS roots in a TPA-induced acute inflammation mouse model demonstrated a significant reduction in ear edema. The extracts were further tested on purified enzymes for COX-1 and COX-2 inhibition to elucidate their mechanism of action, and a strong inhibition was observed. Six anthraquinones and two naphthalene derivatives were isolated from the ethyl acetate extract. Among the isolated compounds, emodin was found to be a potent inhibitor with slight selectivity towards COX-2, and nepodin exhibited selectivity towards COX-1. Emodin, endocrocin, and nepodin also exhibited significant topical anti-inflammatory activity in mice. Interestingly, nepodin showed better radical scavenging activity than trolox and ascorbic acid against DPPH and ABTS radicals. The strong radical scavenging activity of chloroform and ethyl acetate extracts could be explained by the presence of nepodin as well as by the high phenolic content of the ethyl acetate extract. Thus, the anti-inflammatory effect of R. NEPALENSIS roots was assumed to be mediated through COX inhibition by anthraquinones and naphthalene derivatives and through the radical scavenging activities of naphthalene derivatives. PMID:20379952

Gautam, Raju; Karkhile, Kailas V; Bhutani, Kamlesh K; Jachak, Sanjay M

2010-10-01

189

Interaction of a selective cyclooxygenase-2 inhibitor with aspirin and NO-releasing aspirin in the human gastric mucosa  

PubMed Central

In addition to inhibiting cyclooxygenase (COX)-1-derived prostanoid biosynthesis, aspirin acetylates COX-2, enabling the conversion of arachidonic acid to 15(R)-epi lipoxin A4, or aspirin-triggered lipoxin (ATL). Selective COX-2 inhibitors block ATL formation and exacerbate mucosal injury in rats treated with aspirin. In the present study, we have examined whether inhibition of COX-2 activity in healthy volunteers taking aspirin exacerbates gastric mucosal injury and if such an effect would be prevented by NCX-4016, a NO-releasing derivative of aspirin. Thirty-two volunteers were randomized to receive 2 wk of treatment with NCX-4016 (800 mg twice a day) or aspirin (100 mg once a day) alone or in combination with 200 mg of celecoxib twice a day. Mucosal damage was assessed by endoscopy. The mean mucosal injury score was 5.8 ± 1.8 in subjects treated with aspirin and 2.4 ± 0.7 (P < 0.01 vs. aspirin) in subjects treated with NCX-4016. Administration of celecoxib increased the injury score in volunteers treated with aspirin (9.9 ± 1.9) but not in subjects taking NCX-4016 (1.5 ± 0.8). Aspirin and NCX-4016 caused a comparable suppression of serum thromboxane B2 levels and increased urinary excretion of ATL. Celecoxib inhibited endotoxin-induced prostaglandin E2 generation in whole blood by ?80% and abolished ATL formation. These findings suggests that (i) aspirin and NCX-4016 trigger ATL formation in humans, (ii) celecoxib inhibits ATL formation and exacerbates the mucosal injury caused by low doses of aspirin, and (iii) the NO-donating moiety of NCX-4016 protects the gastric mucosa even in the presence of suppression of COX-1 and COX-2. PMID:12960371

Fiorucci, Stefano; Santucci, Luca; Wallace, John L.; Sardina, Marco; Romano, Mario; del Soldato, Piero; Morelli, Antonio

2003-01-01

190

Disturbance of peristalsis in the guinea-pig isolated small intestine by indomethacin, but not cyclo-oxygenase isoform-selective inhibitors  

PubMed Central

Since the cyclo-oxygenase (COX) isoform-nonselective inhibitor indomethacin is known to modify intestinal motility, we analysed the effects of COX-1 and COX-2 inhibition on intestinal peristalsis. Peristalsis in isolated segments of the guinea-pig small intestine was triggered by a rise of the intraluminal pressure and recorded via the pressure changes associated with peristalsis. The COX-1 inhibitor SC-560, the COX-2 inhibitor NS-398 (both at 0.1 ?–?1??M) and the isoform-nonselective inhibitors flurbiprofen (0.01?–?10??M) and piroxicam (0.1?–?50??M) were without major influence on peristalsis, whereas indomethacin and etodolac (0.1?–?10??M) disturbed the regularity of peristalsis by causing nonpropulsive circular muscle contractions. Radioimmunoassay measurements showed that SC-560, NS-398, indomethacin and etodolac (each at 1??M) suppressed the release of 6-keto-prostaglandin F1? (6-keto-PGF1?) from the intestinal segments. Reverse transcription?–?polymerase chain reaction tests revealed that, relative to glyceraldehyde-3 phosphate dehydrogenase ribonucleic acid, the expression of COX-1 mRNA increased by a factor of 2.0 whereas that of COX-2 mRNA rose by a factor of 7.9 during the 2?h experimental period. Pharmacological experiments indicated that the action of indomethacin to disturb intestinal peristalsis was unrelated to inhibition of L-type calcium channels, adenosine triphosphate-sensitive potassium channels or phosphodiesterase type IV. These results show that selective inhibition of COX-1 and COX-2 does not grossly alter peristaltic motor activity in the guinea-pig isolated small intestine and that the effect of indomethacin to disturb the regular pattern of propulsive motility in this species is unrelated to COX inhibition. PMID:11250881

Shahbazian, Anaid; Schuligoi, Rufina; Heinemann, Akos; Peskar, Bernhard A; Holzer, Peter

2001-01-01

191

Selective serotonin reuptake inhibitor discontinuation during pregnancy  

PubMed Central

Abstract Question I have a patient who discontinued her selective serotonin reuptake inhibitor in pregnancy against my advice owing to fears it might affect the baby. She eventually attempted suicide. How can we deal effectively with this situation? Answer The “cold turkey” discontinuation of needed antidepressants is a serious public health issue strengthened by fears and misinformation. It is very important for physicians to ensure that evidence-based information is given to women in a way that is easy to understand. The risks of untreated moderate to severe depression far outweigh the theoretical risks of taking selective serotonin reuptake inhibitors.

Ejaz, Resham; Leibson, Tom; Koren, Gideon

2014-01-01

192

Inhibitors Selective for Mycobacterial Versus Human Proteasomes  

SciTech Connect

Many anti-infectives inhibit the synthesis of bacterial proteins, but none selectively inhibits their degradation. Most anti-infectives kill replicating pathogens, but few preferentially kill pathogens that have been forced into a non-replicating state by conditions in the host. To explore these alternative approaches we sought selective inhibitors of the proteasome of Mycobacterium tuberculosis. Given that the proteasome structure is extensively conserved, it is not surprising that inhibitors of all chemical classes tested have blocked both eukaryotic and prokaryotic proteasomes, and no inhibitor has proved substantially more potent on proteasomes of pathogens than of their hosts. Here we show that certain oxathiazol-2-one compounds kill non-replicating M.?tuberculosis and act as selective suicide-substrate inhibitors of the M.?tuberculosis proteasome by cyclocarbonylating its active site threonine. Major conformational changes protect the inhibitor-enzyme intermediate from hydrolysis, allowing formation of an oxazolidin-2-one and preventing regeneration of active protease. Residues outside the active site whose hydrogen bonds stabilize the critical loop before and after it moves are extensively non-conserved. This may account for the ability of oxathiazol-2-one compounds to inhibit the mycobacterial proteasome potently and irreversibly while largely sparing the human homologue.

Lin, G.; Li, D; Sorio de Carvalho, L; Deng, H; Tao, H; Vogt, G; Wu, K; Schneider, J; Chidawanyika, T; et. al.

2009-01-01

193

Cyclooxygenase Inhibitors Block Cell Growth, Increase Ceramide and Inhibit Cell Cycle  

Microsoft Academic Search

We have shown previously in a model of metastatic breast cancer that murine mammary tumor cells express both cyclooxygenase-1 (Cox-1) and Cox-2 isoforms. Growth and metastasis of these tumors in syngeneic hosts are inhibited by either selective Cox-1 (SC560) or selective Cox-2 (celecoxib) inhibitors. To gain insight into the relevant mechanisms involved in the therapeutic response, we determined the effect

Namita Kundu; Miriam J. Smyth; Leigh Samsel; Amy M. Fulton

2002-01-01

194

Alveolate and chlorophycean mitochondrial cox2 genes split twice independently  

Microsoft Academic Search

The mitochondrial gene for COXII is typically encoded in the organelle genome, however in some members of two unrelated groups, Apicomplexa and Chlorophyceae, cox2 is split into two genes, and both are encoded in the nucleus. Rare genomic changes (RGCs) have acquired popularity as phylogenetic markers, and accordingly this rearrangement of cox2 has been used to infer a possible source

Ross F. Waller; Patrick J. Keeling

2006-01-01

195

Synthesis and biological evaluation of 1,3-diphenylprop-2-en-1-ones possessing a methanesulfonamido or an azido pharmacophore as cyclooxygenase-1/-2 inhibitors.  

PubMed

A group of (E)-1,3-diphenylprop-2-en-1-one derivatives (chalcones) possessing a MeSO(2)NH, or N(3), COX-2 pharmacophore at the para-position of the C-1 phenyl ring were synthesized using a facile stereoselective Claisen-Schmidt condensation reaction. In vitro COX-1/COX-2 structure-activity relationships were determined by varying the substituents on the C-3 phenyl ring (4-H, 4-Me, 4-F, and 4-OMe). Among the 1,3-diphenylprop-2-en-1-ones possessing a C-1 para-MeSO(2)NH COX-2 pharmacophore, (E)-1-(4-methanesulfonamidophenyl)-3-(4-methylphenyl)prop-2-en-1-one (7b) was identified as a selective COX-2 inhibitor (COX-2 IC(50)=1.0 microM; selectivity index >100) that was less potent than the reference drug rofecoxib (COX-2 IC(50)=0.50 microM; SI>200). The corresponding 1,3-diphenylprop-2-en-1-one analogue possessing a C-1 para-N(3) COX-2 pharmacophore, (E)-1-(4-azidophenyl)-3-(4-methylphenyl)prop-2-en-1-one (7f), exhibited potent and selective COX-2 inhibition (COX-1 IC(50)=22.2 microM; COX-2 IC(50)=0.3 microM; SI=60). A molecular modeling study where 7b and 7f were docked in the binding site of COX-2 showed that the p-MeSO(2)NH and N(3) substituents on the C-1 phenyl ring are oriented in the vicinity of the COX-2 secondary pocket (His90, Arg513, Phe518, and Val523). The structure-activity data acquired indicate that the propenone moiety constitutes a suitable scaffold to design new acyclic 1,3-diphenylprop-2-en-1-ones with selective COX-1 or COX-2 inhibitory activity. PMID:16798002

Zarghi, Afshin; Zebardast, Tannaz; Hakimion, Farinaz; Shirazi, Farshad H; Rao, P N Praveen; Knaus, Edward E

2006-10-15

196

COX-2/PGE2: molecular ambassadors of Kaposi's sarcoma-associated herpes virus oncoprotein-v-FLIP.  

PubMed

Kaposi's sarcoma herpesvirus (KSHV) latent oncoprotein viral FLICE (FADD-like interferon converting enzyme)-like inhibitory protein (v-FLIP) or K13, a potent activator of NF-?B, has well-established roles in KSHV latency and oncogenesis. KSHV-induced COX-2 represents a novel strategy employed by KSHV to promote latency and inflammation/angiogenesis/invasion. Here, we demonstrate that v-FLIP/K13 promotes tumorigenic effects via the induction of host protein COX-2 and its inflammatory metabolite PGE2 in an NF-?B-dependent manner. In addition to our previous studies demonstrating COX-2/PGE2's role in transcriptional regulation of KSHV latency promoter and latent gene expression, the current study adds to the complexity that though LANA-1 (latency associated nuclear antigen) is utilizing COX-2/PGE2 as critical factors for its transcriptional regulation, it is the v-FLIP/K13 gene in the KSHV latency cluster that maintains continuous COX-2/PGE2 levels in the infected cells. We demonstrate that COX-2 inhibition, via its chemical inhibitors (NS-398 or celecoxib), reduced v-FLIP/K13-mediated NF-?B induction, and extracellular matrix (ECM) interaction-mediated signaling, mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) levels, and subsequently downregulated detachment-induced apoptosis (anoikis) resistance. vFLIP expression mediated the secretion of cytokines, and spindle cell differentiation activated the phosphorylation of p38, RSK, FAK, Src, Akt and Rac1-GTPase. The COX-2 inhibition in v-FLIP/K13-HMVECs reduced inflammation and invasion/metastasis-related genes, along with reduced anchorage-independent colony formation via modulating 'extrinsic' as well as 'intrinsic' cell death pathways. COX-2 blockade in v-FLIP/K13-HMVEC cells drastically augmented cell death induced by removal of essential growth/survival factors secreted in the microenvironment. Transformed cells obtained from anchorage-independent colonies of COX-2 inhibitor-treated v-FLIP/K13-HMVEC cells expressed lower levels of endothelial-mesenchymal transition genes such as slug, snail and twist, and higher expression of the tumor-suppressor gene, E-cadherin. Taken together, our study provides strong evidences that FDA-approved COX-2 inhibitors have great potential in blocking tumorigenic events linked to KSHV's oncogenic protein v-FLIP/K13. PMID:23552603

Sharma-Walia, N; Patel, K; Chandran, K; Marginean, A; Bottero, V; Kerur, N; Paul, A G

2012-01-01

197

Dual carbonic anhydrase--cyclooxygenase-2 inhibitors.  

PubMed

Cyclooxygenase is a key enzyme responsible for metabolisation of arachidonic acid into prostaglandins and thromboxane. This enzyme is the target of non steroidal anti-inflammatory drugs (NSAIDs), used against inflammation and pain. The inducible COX-2 was associated with inflammatory conditions, whereas the constitutive form (COX-1) was responsible for the beneficial effects of the PGs. This observation led to the development of COX-2 inhibitors or "coxibs" of which rofecoxib (Vioxx) characterized by a methylsulfone moiety and the sulfonamides celecoxib (Celebrex) and valdecoxib (Bextra). Initially described as COX-2 "selective" inhibitors, recent reports revealed a nanomolar inhibition activity of the sulfonamide COX-2 inhibitors for several carbonic anhydrase (CA) isoforms, confirmed by X-ray crystal structures for the adducts of celecoxib and valdecoxib with isozyme CA II. This dual activity may help to explain differences in clinical observation between sulfonamide and methylsulfone COX-2 inhibitors. Moreover, the inhibition of CA isozymes, critical for the development and invasion of cancer cells, such as CA II, IX and XII, may constitute an important mechanism of antitumor action of such sulfonamide compounds. PMID:17504133

Dogné, Jean-Michel; Thiry, Anne; Pratico, Domenico; Masereel, Bernard; Supuran, Claudiu T

2007-01-01

198

Genetic selection for peptide inhibitors of angiogenin  

PubMed Central

The improper regulation of angiogenesis is implicit in a variety of diseases, including cancer. Angiogenin is unique among angiogenic factors in its having ribonucleolytic activity. Inhibitors of this activity could serve as chemotherapeutics. The ribonucleolytic activity of angiogenin is toxic to the Origami™ strain of Escherichia coli. Herein, this cytotoxicity was used to identify inhibitors from a random nonapeptide library tethered to the C-terminus of human angiogenin. The selected sequences fell into three classes: (1) extremely hydrophobic, (2) putative ClpXP substrates, and (3) slightly anionic. Two peptides corresponding to sequences in the last class were synthesized chemically and found to inhibit the ribonucleolytic activity of human angiogenin in vitro with micromolar values of Ki. Both peptides also inhibit bovine pancreatic ribonuclease, a homologue of angiogenin, though one exhibits selectivity for angiogenin. The affinity and selectivity of these peptides are comparable to the best known inhibitors of angiogenin. Moreover, the strategy used to identify them is general and could be applied to other cytotoxins. PMID:18308863

Smith, Bryan D.; Raines, Ronald T.

2008-01-01

199

Cyclic compressive loading on 3D tissue of human synovial fibroblasts upregulates prostaglandin E2 via COX-2 production without IL-1? and TNF-?  

PubMed Central

Objective Excessive mechanical stress on synovial joints causes osteoarthritis (OA) and results in the production of prostaglandin E2 (PGE2), a key molecule in arthritis, by synovial fibroblasts. However, the relationship between arthritis-related molecules and mechanical stress is still unclear. The purpose of this study was to examine the synovial fibroblast response to cyclic mechanical stress using an in vitro osteoarthritis model. Method Human synovial fibroblasts were cultured on collagen scaffolds to produce three-dimensional constructs. A cyclic compressive loading of 40 kPa at 0.5 Hz was applied to the constructs, with or without the administration of a cyclooxygenase-2 (COX-2) selective inhibitor or dexamethasone, and then the concentrations of PGE2, interleukin-1? (IL-1?), tumour necrosis factor-? (TNF-?), IL-6, IL-8 and COX-2 were measured. Results The concentrations of PGE2, IL-6 and IL-8 in the loaded samples were significantly higher than those of unloaded samples; however, the concentrations of IL-1? and TNF-? were the same as the unloaded samples. After the administration of a COX-2 selective inhibitor, the increased concentration of PGE2 by cyclic compressive loading was impeded, but the concentrations of IL-6 and IL-8 remained high. With dexamethasone, upregulation of PGE2, IL-6 and IL-8 was suppressed. Conclusion These results could be useful in revealing the molecular mechanism of mechanical stress in vivo for a better understanding of the pathology and therapy of OA. Cite this article: Bone Joint Res 2014;3:280–8. PMID:25237168

Shimomura, K.; Kanamoto, T.; Kita, K.; Akamine, Y.; Nakamura, N.; Mae, T.; Yoshikawa, H.; Nakata, K.

2014-01-01

200

p50-associated COX-2 extragenic RNA (PACER) activates COX-2 gene expression by occluding repressive NF-?B complexes  

PubMed Central

Deregulated expression of COX-2 has been causally linked to development, progression, and outcome of several types of human cancer. We describe a novel fundamental level of transcriptional control of COX-2 expression. Using primary human mammary epithelial cells and monocyte/macrophage cell lines, we show that the chromatin boundary/insulator factor CTCF establishes an open chromatin domain and induces expression of a long non-coding RNA within the upstream promoter region of COX-2. Upon induction of COX-2 expression, the lncRNA associates with p50, a repressive subunit of NF-?B, and occludes it from the COX-2 promoter, potentially facilitating interaction with activation-competent NF-?B p65/p50 dimers. This enables recruitment of the p300 histone acetyltransferase, a domain-wide increase in histone acetylation and assembly of RNA Polymerase II initiation complexes. Our findings reveal an unexpected mechanism of gene control by lncRNA-mediated repressor occlusion and identify the COX-2-lncRNA, PACER, as a new potential target for COX-2-modulation in inflammation and cancer. DOI: http://dx.doi.org/10.7554/eLife.01776.001 PMID:24843008

Krawczyk, Michal; Emerson, Beverly M

2014-01-01

201

p50-associated COX-2 extragenic RNA (PACER) activates COX-2 gene expression by occluding repressive NF-?B complexes.  

PubMed

Deregulated expression of COX-2 has been causally linked to development, progression, and outcome of several types of human cancer. We describe a novel fundamental level of transcriptional control of COX-2 expression. Using primary human mammary epithelial cells and monocyte/macrophage cell lines, we show that the chromatin boundary/insulator factor CTCF establishes an open chromatin domain and induces expression of a long non-coding RNA within the upstream promoter region of COX-2. Upon induction of COX-2 expression, the lncRNA associates with p50, a repressive subunit of NF-?B, and occludes it from the COX-2 promoter, potentially facilitating interaction with activation-competent NF-?B p65/p50 dimers. This enables recruitment of the p300 histone acetyltransferase, a domain-wide increase in histone acetylation and assembly of RNA Polymerase II initiation complexes. Our findings reveal an unexpected mechanism of gene control by lncRNA-mediated repressor occlusion and identify the COX-2-lncRNA, PACER, as a new potential target for COX-2-modulation in inflammation and cancer.DOI: http://dx.doi.org/10.7554/eLife.01776.001. PMID:24843008

Krawczyk, Michal; Emerson, Beverly M

2014-01-01

202

Reduction of pathological and behavioral deficits following spinal cord contusion injury with the selective cyclooxygenase-2 inhibitor NS-398.  

PubMed

Spinal cord injury (SCI) results in loss of locomotor function and development of abnormal chronic pain syndromes (mechanical allodynia, thermal hyperalgesia). Following injury, secondary mechanisms including release of excitatory amino acids, inflammation and lipid peroxidation damage neural cells through release of cytotoxic free radicals. We hypothesized that selective inhibition of cyclooxygenase-2 (COX-2), an inducible inflammatory mediator, would decrease tissue damage and subsequently reduce locomotor deficits and development of chronic central pain syndromes after injury. Fifteen minutes prior to receiving T13 spinal segment spinal cord contusion injury, 200-225-g male Sprague-Dawley rats received either vehicle (0.5 ml 1:1 v/v DMSO/saline, i.p., n = 20) or the selective COX-2 inhibitor NS-398 (5 mg/kg in DMSO/saline v/v, i.p., n = 20). Locomotor function via the BBB scale, and nociceptive behaviors measured by paw withdrawals to von Frey filaments and radiant heat stimuli were tested for 4 weeks postinjury. Histological examination and volumetric analysis of spinal cord tissue were performed concomitantly. Spinally contused animals receiving NS-398 demonstrated significantly (p < 0.05) reduced locomotor alteration and reductions in both fore- and hindlimb mechanical allodynia and thermal hyperalgesia when compared to vehicle controls. Histological examination of spinal segments at the lesion segment demonstrated reduced lesion extent and increased viable tissue when compared to vehicle controls. Prostaglandin E2 levels were significantly lowered in NS-398-treated but not vehicle-treated animals 12 h after injury. These results support the role of COX-2 in reducing pathological and behavioral deficits after spinal cord injury. PMID:11336442

Hains, B C; Yucra, J A; Hulsebosch, C E

2001-04-01

203

A new potential cyclooxygenase-2 inhibitor, pyridinic analogue of nimesulide.  

PubMed

In this paper, the binding mode of original pyridinic compounds structurally related to nimesulide, a preferential cyclooxygenase (COX)-2 inhibitor, is analyzed by docking simulations in order to understand structure-activity relationships of this family. Structural modifications are proposed to reverse the selectivity of the more active inhibitor of the series characterized by a preferential activity on COX-1. On the basis of these modifications, a new compound with a bromo substituent was designed and showed a COX-2 selective inhibition. PMID:16225966

Michaux, Catherine; Charlier, Caroline; Julémont, Fabien; de Leval, Xavier; Dogné, Jean-Michel; Pirotte, Bernard; Durant, François

2005-12-01

204

Aspirin inhibits lipopolysaccharide-induced COX-2 expression and PGE2 production in porcine alveolar macrophages by modulating protein kinase C and protein tyrosine phosphatase activity  

PubMed Central

Aspirin has been demonstrated to be effective in inhibiting COX-2 and PGE2 in Alveolar macrophages (AMs). However, the mechanisms have not been fully understood. In the present study, we found that pretreatment with aspirin inhibited LPS-induced COX-2 and PGE2 upregulation, I?B? degradation, NF?B activation and the increase of PKC activity, but elevated LPS-induced the decrease of PTP activity. The PKC inhibitor calphostin C dramatically reduced the COX-2 mRNA and PGE2 levels, but the PTP inhibitor peroxovanadium (POV) significantly increased the COX-2 mRNA and PGE2 levels. Furthermore, the PTP inhibitor mitigated the inhibitory effect of aspirin on COX-2 and PGE2 upregulation and NF-?B activation, whereas the PKC inhibitor enhanced the inhibitory effects of aspirin on the production of COX-2 and PGE2. Our data indicate a novel mechanism by which aspirin acts as a potent anti-inflammatory agent in alveolus macrophages and ALI. [BMB Reports 2014; 47(1): 45-50] PMID:24209633

Duan, Yuzhong; Chen, Fanglin; Zhang, Anmei; Zhu, Bo; Sun, Jianguo; Xie, Qichao; Chen, Zhengtang

2014-01-01

205

Radiosynthesis of a ¹?F-labeled 2,3-diarylsubstituted indole via McMurry coupling for functional characterization of cyclooxygenase-2 (COX-2) in vitro and in vivo.  

PubMed

The radiosynthesis of 3-(4-[(18)F]fluorophenyl)-2-(4-methylsulfonylphenyl)-1H-indole [(18)F]-3 as potential PET radiotracer for functional characterization of cyclooxygenase-2 (COX-2) in vitro and in vivo is described. [(18)F]-3 was prepared by McMurry cyclization of a (18)F-labeled intermediate with low valent titanium and zinc via a two-step procedure in a remote controlled synthesizer unit including HPLC purification and solid phase extraction. In this way [(18)F]-3 was synthesized in 80 min synthesis time in 10% total decay corrected yield from [(18)F]fluoride in radiochemical purity >98% and a specific activity of 74-91 GBq/?mol (EOS). [(18)F]-3 was evaluated in vitro using pro-inflammatory stimulated THP-1 and COX-2 expressing tumor cell lines (FaDu, A2058, HT-29), where the radiotracer uptake was shown to be consistent with up regulated COX-2 expression. The stability of [(18)F]-3 was determined by incubation in rat whole blood and plasma in vitro and by metabolite analysis of arterial blood samples in vivo, showing with 75% of original compound after 60 min an acceptable high metabolic stability. However, no substantial tumor accumulation of [(18)F]-3 could be observed by dynamic small animal PET studies on HT-29 tumor-bearing mice in vivo. This may be due to the only moderate COX-1/COX-2 selectivity of 3 as demonstrated by both cellular and enzymatic cyclooxygenase inhibition assay in vitro. Nevertheless, the new approach first using McMurry cyclization in (18)F-chemistry gives access to (18)F-labeled diarylsubstituted heterocycles that hold promise as radiolabeled COX-2 inhibitors. PMID:22560838

Kniess, Torsten; Laube, Markus; Bergmann, Ralf; Sehn, Fabian; Graf, Franziska; Steinbach, Joerg; Wuest, Frank; Pietzsch, Jens

2012-06-01

206

Direct Sequencing of Cyclooxygenase-2 (COX-2) Revealed an Intronic Variant rs201231411 in Iranian Patients with Pancreatic Cancer  

PubMed Central

BACKGROUND There are hoarding documents for the biological importance of cyclooxygenase-2 (COX-2) in pancreatic carcinogenesis. We aimed to thoroughly investigate the DNA sequence variations of whole COX-2 exons in a large case-control study of pancreatic cancer by direct sequencing. METHODS The entire exonic regions of COX-2 including 10 exons were sequenced in the germline DNA of 96 patients with pancreatic cancer. Selected variants within exons six to seven (E6E7) amplicon from the test panel were genotyped in 96 controls. RESULTS The COX-2 gene was demonstrated to be genetically conserved. Four missense mutations were found in three cases. However the common variant c.724-10_724-7delATTT (rs201231411) that is located in intron 6, showed significant difference between cases and controls (21 [21.9%] vs 11 [%11.5], p=0.05). CONCLUSION This study determined that COX-2 has a conservative sequence, which is required for its enzymatic activity and supports the important role of this enzyme’s expression in pancreatic cancer rather than any changes in its activity. The effect of intronic variant rs201231411 on COX-2 expression could be analyzed in future studies.

Mohamadkhani, Ashraf; Akbari, Mohammad Reza; Ghanbari, Reza; Naderi, Elnaz; Rezanejad-Asl, Parisa; Pourshams, Akram

2015-01-01

207

Synthesis and biological evaluation of linear phenylethynylbenzenesulfonamide regioisomers as cyclooxygenase-1/-2 (COX-1/-2) inhibitors.  

PubMed

A group of regioisomeric phenylethynylbenzenesulfonamides possessing a COX-2 SO2NH2 pharmacophore at the para-, meta- or ortho-position of the C-1 phenyl ring, in conjunction with a C-2 substituted-phenyl (H, OMe, OH, Me, F) group, were synthesized and evaluated as inhibitors of the cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) isozymes. The target 1,2-diphenylacetylenes were synthesized via a palladium-catalyzed Sonogashira cross-coupling reaction. In vitro COX-1/-2 isozyme inhibition structure-activity data showed that COX-1/-2 inhibition and the COX selectivity index (SI) are sensitive to the regioisomeric placement of the COX-2 SO2NH2 pharmacophore where the COX-2 potency order for the benzenesulfonamide regioisomers was generally meta>para and ortho. Among this group of compounds, the in vitro COX-1/-2 isozyme inhibition studies identified 3-(2-phenylethynyl)benzenesulfonamide (10a) as a COX-2 inhibitor (COX-2 IC50=0.45 microM) with a good COX-2 selectivity (COX-2 SI=70). In contrast, 2-[2-(3-fluorophenyl)ethynyl]benzenesulfonamide (11c) possessing a SO2NH2 COX-2 pharmacophore at the ortho-position of the C-1 phenyl ring exhibited COX-1 inhibition and selectivity (COX-1 IC50=3.6 microM). A molecular modeling study where 10a was docked in the binding site of COX-2 shows that the meta-SO2NH2 COX-2 pharmacophore was inserted inside the COX-2 secondary pocket (Arg513, Phe518, Val523, and His90). Similar docking of 10a within the COX-1 binding site shows that the meta-SO2NH2 pharmacophore is unable to interact with the respective amino acid residues in COX-1 that correspond to those near the secondary pocket in COX-2 due to the presence of the larger Ile523 in COX-1 that replaces Val523 in COX-2. PMID:16635574

Anana, Raymond; Rao, P N Praveen; Chen, Qiao-Hong; Knaus, Edward E

2006-08-01

208

Clinical pharmacology of lumiracoxib, a second-generation cyclooxygenase 2 selective inhibitor.  

PubMed

Although highly selective cyclooxygenase (COX)-2 inhibitors have been shown to be less toxic to the gastrointestinal tract than conventional non-steroidal anti-inflammatory drugs (NSAIDs), their overall safety profile is questioned. Since different selective COX-2 inhibitors were found to be associated with increased cardiovascular thrombotic events, the thrombotic hazard may be a class effect. Furthermore, warnings have been issued regarding serious skin and hypersensitivity reactions associated with valdecoxib. Lumiracoxib is a novel COX-2 selective inhibitor (coxib) with improved biochemical selectivity over that of currently available coxibs. It is structurally distinct from other drugs in the class and has weakly acidic properties. Clinical studies support a once-daily dosing regimen, despite its relatively short plasma elimination half-life (3 - 6 h). In randomised, controlled clinical trials, lumiracoxib 100 - 200 mg/day has been shown to be superior to placebo in patients with symptomatic osteoarthritis, with clinical efficacy similar to diclofenac 150 mg/day, celecoxib 200 mg/day or rofecoxib 25 mg/day. Furthermore, lumiracoxib 200 - 400 mg/day appeared to be effective in patients with rheumatoid arthritis. In patients with acute pain related to primary dysmenorrhoea, dental or orthopaedic surgery, lumiracoxib 400 mg/day was found to be at least as effective as standard doses of traditional NSAIDs and other coxibs. Endoscopic studies have indicated that lumiracoxib is associated with a rate of gastroduodenal ulcer formation that is significantly lower than with ibuprofen and does not differ from celecoxib. In the Therapeutic Arthritis Research and Gastrointestinal Trial, which enrolled 18,325 patients with osteoarthritis, the cumulative 1-year incidence of ulcer complications (primary end point) was significantly reduced by approximately threefold on lumiracoxib 400 mg/day compared with naproxen 1000 mg/day or ibuprofen 2400 mg/day (0.32 versus 0.91%). Reduction in ulcer complications was more pronounced in the population not taking low-dose aspirin (0.2 versus 0.92%, respectively). Conversely, the gastrointestinal advantage of lumiracoxib was abrogated in patients receiving low-dose aspirin (0.69 versus 0.88%, respectively, p = 0.49). Regarding cardiovascular events contributing to the trialists' composite end point (myocardial infarction, stroke or cardiovascular death), there was no significant difference between lumiracoxib (0.65%) versus combined comparator NSAIDs (0.55%). Similarly, no significant difference was recorded in rates of myocardial infarction (clinical and silent) between the lumiracoxib (0.25%) and the combined NSAID (0.19%) treatment groups. Liver function test abnormalities were more frequent with lumiracoxib (2.57%) than with the comparator NSAIDs (0.63%). Whether or not this would result in an increased risk of clinical hepatitis in the real world setting is unforeseeable. PMID:15882125

Bannwarth, Bernard; Berenbaum, Francis

2005-04-01

209

Synthesis, pharmacological characterization, and docking analysis of a novel family of diarylisoxazoles as highly selective cyclooxygenase-1 (COX-1) inhibitors.  

PubMed

3-(5-Chlorofuran-2-yl)-5-methyl-4-phenylisoxazole (P6), a known selective cyclooxygenase-1 (COX-1) inhibitor, was used to design a new series of 3,4-diarylisoxazoles in order to improve its biochemical COX-1 selectivity and antiplatelet efficacy. Structure-activity relationships were studied using human whole blood assays for COX-1 and COX-2 inhibition in vitro, and results showed that the simultaneous presence of 5-methyl (or -CF3), 4-phenyl, and 5-chloro(-bromo or -methyl)furan-2-yl groups on the isoxazole core was essential for their selectivity toward COX-1. 3g, 3s, 3d were potent and selective COX-1 inhibitors that affected platelet aggregation in vitro through the inhibition of COX-1-dependent thromboxane (TX) A2. Moreover, we characterized their kinetics of COX-1 inhibition. 3g, 3s, and 3d were more potent inhibitors of platelet COX-1 and aggregation than P6 (named 6) for their tighter binding to the enzyme. The pharmacological results were supported by docking simulations. The oral administration of 3d to mice translated into preferential inhibition of platelet-derived TXA2 over protective vascular-derived prostacyclin (PGI2). PMID:23651359

Vitale, Paola; Tacconelli, Stefania; Perrone, Maria Grazia; Malerba, Paola; Simone, Laura; Scilimati, Antonio; Lavecchia, Antonio; Dovizio, Melania; Marcantoni, Emanuela; Bruno, Annalisa; Patrignani, Paola

2013-06-13

210

COX-2 drives metastatic breast cells from brain lesions into the cerebrospinal fluid and systemic circulation.  

PubMed

Breast cancer is among the most common malignancies that metastasize to the brain, with 15% to 20% of patients with metastatic breast cancer eventually developing brain metastases. We previously reported a method to enumerate tumor cells in the cerebrospinal fluid (CSF) of patients with breast cancer with central nervous system (CNS) metastases, a setting that lacks sufficiently informative biomarkers. Here, we show that breast cancer cells can spontaneously disseminate into the CSF from brain lesions in mice in a COX-2-dependent manner and can escape from the CNS to systemic circulation. Enumeration of tumor cells in the peripheral blood (circulating tumor cells, CTC) and CSF (cerebrospinal fluid tumor cells, CSFTC) of nine breast cancer patients with brain metastases revealed dynamic changes in tumor cell burden in both the peripheral blood and CSF compartments that correlated with clinical disease progression. Interestingly, four of the enrolled patients exhibited rapid intercompartmental transitioning of the disease reflected in the CTC and CSFTC counts that preceded corresponding evidence by clinical imaging or neurologic symptoms. Two of these patients had systemic disease recurrence involving the primary malignant site. Intercompartmental cycling of tumor cells may represent an important mechanism for disease persistence and recurrence that may involve tumor self-seeding. Our findings demonstrate the involvement of COX-2 in the genesis of CSFTCs and suggest that COX-2 inhibitors should be investigated in patients with breast cancer with brain metastases for their ability to reduce CSFTC counts and prevent systemic recurrence. PMID:24614081

Allen, Joshua E; Patel, Akshal S; Prabhu, Varun V; Dicker, David T; Sheehan, Jonas M; Glantz, Michael J; El-Deiry, Wafik S

2014-05-01

211

Corrosion inhibitor screening tests and selection for field applications  

SciTech Connect

Organic corrosion inhibitors have been widely used in oil and gas wells, pipelines, gathering lines and process facilities to inhibit corrosion for quite some time. This paper describes and discusses laboratory screening test parameters and methods for evaluating and selecting corrosion inhibitors for use in downhole and pipeline corrosion inhibitions or mitigations. Field application results of the laboratory selected inhibitors are presented to illustrate the consistency of the selected inhibitor in field applications. The inhibitor adverse effect in various conditions and environments are also discussed.

Wu, Y. [Phillips Petroleum Co., Bartlesville, OK (United States)

1994-12-31

212

Molecular basis of cyclooxygenase enzymes (COXs) selective inhibition.  

PubMed

The widely used nonsteroidal anti-inflammatory drugs block the cyclooxygenase enzymes (COXs) and are clinically used for the treatment of inflammation, pain, and cancers. A selective inhibition of the different isoforms, particularly COX-2, is desirable, and consequently a deeper understanding of the molecular basis of selective inhibition is of great demand. Using an advanced computational technique we have simulated the full dissociation process of a highly potent and selective inhibitor, SC-558, in both COX-1 and COX-2. We have found a previously unreported alternative binding mode in COX-2 explaining the time-dependent inhibition exhibited by this class of inhibitors and consequently their long residence time inside this isoform. Our metadynamics-based approach allows us to illuminate the highly dynamical character of the ligand/protein recognition process, thus explaining a wealth of experimental data and paving the way to an innovative strategy for designing new COX inhibitors with tuned selectivity. PMID:20215464

Limongelli, Vittorio; Bonomi, Massimiliano; Marinelli, Luciana; Gervasio, Francesco Luigi; Cavalli, Andrea; Novellino, Ettore; Parrinello, Michele

2010-03-23

213

Studies on the metabolism of the novel, selective cyclooxygenase-2 inhibitor indomethacin phenethylamide in rat, mouse, and human liver microsomes: identification of active metabolites.  

PubMed

The metabolism of 2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]-N-phenethyl-acetamide (indomethacin phenethylamide, LM-4108), a highly selective cyclooxygenase-2 inhibitor, was studied in rat, mouse, and human liver microsomes. The primary site of oxidation in all species examined was on the methylene carbons of the phenethyl side chain to form the 1'- and 2'-hydroxy and 2'-oxo metabolites as determined by electrospray ionization liquid chromatography-tandem mass spectrometry. Half-lives for the disappearance of 10 microM LM-4108 in rat, human, and mouse liver microsomes (0.15 pmol P450/ml) were 11 min, 21 min, and 51 min, respectively. Indomethacin formation was not observed in incubations with rat, mouse, or human liver microsomes. Both the 2'-hydroxy-LM-4108 and 2'-oxo-LM-4108 metabolites were synthesized and found to be equipotent to the parent compound with regard to COX-2 inhibitory potency and selectivity [2'-hydroxy-LM-4108: IC(50)(COX-2) = 0.06 microM, IC(50)(COX-1) >66 microM; 2'-oxo-LM-4108: IC(50)(COX-2) = 0.05 microM, IC(50)(COX-1) >66 microM]. The formation of the metabolites was strongly inhibited by specific CYP3A4 inhibitors ketoconazole and troleandomycin but not by other isoform-selective inhibitors. These findings were confirmed by demonstrating that cloned, expressed CYP3A4 catalyzed side chain oxidation. O-Demethylation was a minor oxidative pathway in contrast to the metabolism of indomethacin and was catalyzed by CYP2D6. Upon intravenous administration of LM-4108 to Sprague-Dawley rats, oxidative metabolism on the phenethyl side chain constituted the rate-limiting steps in its clearance. The active metabolites, 2'-oxo- and 2'-hydroxy-LM-4108, as well as 1'-hydroxy-LM-4108, were all observed in rat plasma and thus may contribute to COX-2 inhibition in vivo. The glucuronides of 2'hydroxy-LM-4108 and O-desmethyl-2'-hydroxy-LM-4108 were also identified in rat bile. PMID:14709628

Remmel, Rory P; Crews, Brenda C; Kozak, Kevin R; Kalgutkar, Amit S; Marnett, Lawrence J; Algutkar, Amit S

2004-01-01

214

Valdecoxib: assessment of cyclooxygenase-2 potency and selectivity.  

PubMed

The discovery of a second isoform of cyclooxygenase (COX) led to the search for compounds that could selectively inhibit COX-2 in humans while sparing prostaglandin formation from COX-1. Celecoxib and rofecoxib were among the molecules developed from these efforts. We report here the pharmacological properties of a third selective COX-2 inhibitor, valdecoxib, which is the most potent and in vitro selective of the marketed COX-2 inhibitors that we have studied. Recombinant human COX-1 and COX-2 were used to screen for new highly potent and in vitro selective COX-2 inhibitors and compare kinetic mechanisms of binding and enzyme inhibition with other COX inhibitors. Valdecoxib potently inhibits recombinant COX-2, with an IC(50) of 0.005 microM; this compares with IC values of 0.05 microM for celecoxib, 0.5 microM for rofecoxib, and 5 microM for etoricoxib. Unique binding interactions of valdecoxib with COX-2 translate into a fast rate of inactivation of COX-2 (110,000 M/s compared with 7000 M/s for rofecoxib and 80 M/s for etoricoxib). The overall saturation binding affinity for COX-2 of valdecoxib is 2.6 nM (compared with 1.6 nM for celecoxib, 51 nM for rofecoxib, and 260 nM for etoricoxib), with a slow off-rate (t(1/2) approximately 98 min). Valdecoxib inhibits COX-1 in a competitive fashion only at very high concentrations (IC(50) = 150 microM). Collectively, these data provide a mechanistic basis for the potency and in vitro selectivity of valdecoxib for COX-2. Valdecoxib showed similar activity in the human whole-blood COX assay (COX-2 IC(50) = 0.24 microM; COX-1 IC(50) = 21.9 microM). We also determined whether this in vitro potency and selectivity translated to significant potency in vivo. In rats, valdecoxib demonstrated marked potency in acute and chronic models of inflammation (air pouch ED(50) = 0.06 mg/kg; paw edema ED(50) = 5.9 mg/kg; adjuvant arthritis ED(50) = 0.03 mg/kg). In these same animals, COX-1 was spared at doses greater than 200 mg/kg. These data provide a basis for the observed potent anti-inflammatory activity of valdecoxib in humans. PMID:15494548

Gierse, James K; Zhang, Yan; Hood, William F; Walker, Mark C; Trigg, Jennifer S; Maziasz, Timothy J; Koboldt, Carol M; Muhammad, Jerry L; Zweifel, Ben S; Masferrer, Jaime L; Isakson, Peter C; Seibert, Karen

2005-03-01

215

Inhibition of COX-2 expression by topical diclofenac enhanced radiation sensitivity via enhancement of TRAIL in human prostate adenocarcinoma xenograft model  

PubMed Central

Background COX-2 inhibitors have an antitumor potential and have been verified by many researchers. Treatment of cancer cells with external stressors such as irradiation can stimulate the over-expression of COX-2 and possibly confer radiation resistance. In this study, we tested if topical diclofenac, which inhibits both COX-1 and COX-2, administration rendered prostate tumor cells sensitize to the effects of radiation. Methods LNCaP-COX-2 and LNCaP-Neo cells were treated with 0 to 1000 ?M diclofenac. Next, a clonogenic assay was performed in which cells were subjected to irradiation (0 to 4 Gy) with or without diclofenac. COX-2 expression and other relevant molecules were measured by real-time PCR and immunohistochemistry after irradiation and diclofenac treatment. In addition, we assessed the tumor volumes of xenograft LNCaP-COX-2 cells treated with topical diclofenac with or without radiation therapy (RT). Results LNCaP-COX-2 and LNCaP-Neo cell lines experienced cytotoxic effects of diclofenac in a dose related manner. Clonogenic assays demonstrated that LNCaP-COX-2 cells were significantly more resistant to RT than LNCaP-Neo cells. Furthermore, the addition of diclofenac sensitized LNCaP-COX-2 not but LNCaP-Neo cells to the cytocidal effects of radiation. In LNCaP-COX-2 cells, diclofenac enhanced radiation-induced apoptosis compared with RT alone. This phenomenon might be attributed to enhancement of RT-induced TRAIL expression as demonstrated by real-time PCR analysis. Lastly, tumor volumes of LNCaP-COX-2 cells xenograft treated with diclofenac or RT alone was >4-fold higher than in mice treated with combined diclofenac and radiation (p<0.05). Conclusions These in vitro and in vivo findings suggest that conventional COX inhibitor, diclofenac enhances the effect of RT on prostate cancer cells that express COX-2. Thus, diclofenac may have potential as radiosensitizer for treatment of prostate cancer. PMID:23289871

2013-01-01

216

In vitro and ex vivo pharmacodynamics of selected non-steroidal anti-inflammatory drugs in equine whole blood.  

PubMed

Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenases (COX), and the inhibition of COX-2 rather than COX-1 can limit the onset of NSAID-related adverse effects. The pharmacodynamic properties of eltenac, naproxen, tepoxalin, SC-560 and NS 398 in healthy horses were investigated using an in vitro whole blood assay. To predict COX selectivity in clinical use, eltenac and naproxen were also studied ex vivo after intravenous administration. SC-560 acted as a selective COX-1 inhibitor, tepoxalin as a dual inhibitor with potent activity against COX-1, and NS 398 as a preferential COX-2 inhibitor. Eltenac was a preferential COX-2 inhibitor in vitro but un-selective in the ex vivo study. Naproxen maintained its non-selectivity both in vitro and ex vivo. These findings have demonstrated that in vitro studies may not accurately predict in vivo NSAID selectivity for COX and should be confirmed using an ex vivo whole blood assay. PMID:21565533

Cuniberti, B; Odore, R; Barbero, R; Cagnardi, P; Badino, P; Girardi, C; Re, G

2012-03-01

217

Post-translational regulation of COX2 activity by FYN in prostate cancer cells  

PubMed Central

While increased COX2 expression and prostaglandin levels are elevated in human cancers, the mechanisms of COX2 regulation at the post-translational level are unknown. Initial observation that COX2 forms adduct with non-receptor tyrosine kinase FYN, prompted us to study FYN-mediated post-translational regulation of COX2. We found that FYN increased COX2 activity in prostate cancer cells DU145, independent of changes in COX2 or COX1 protein expression levels. We report that FYN phosphorylates human COX2 on Tyr 446, and while corresponding phospho-mimetic COX2 mutation promotes COX2 activity, the phosphorylation blocking mutation prevents FYN-mediated increase in COX2 activity. PMID:24970799

Alexanian, Anna; Miller, Bradley; Chesnik, Marla; Mirza, Shama; Sorokin, Andrey

2014-01-01

218

Cannabidiolic acid as a selective cyclooxygenase-2 inhibitory component in cannabis.  

PubMed

In the present study it was revealed that cannabidiolic acid (CBDA) selectively inhibited cyclooxygenase (COX)-2 activity with an IC(50) value (50% inhibition concentration) around 2 microM, having 9-fold higher selectivity than COX-1 inhibition. In contrast, Delta(9)-tetrahydrocannabinolic acid (Delta(9)-THCA) was a much less potent inhibitor of COX-2 (IC(50) > 100 microM). Nonsteroidal anti-inflammatory drugs containing a carboxyl group in their chemical structures such as salicylic acid are known to inhibit nonselectively both COX-1 and COX-2. CBDA and Delta(9)-THCA have a salicylic acid moiety in their structures. Thus, the structural requirements for the CBDA-mediated COX-2 inhibition were next studied. There is a structural difference between CBDA and Delta(9)-THCA; phenolic hydroxyl groups of CBDA are freed from the ring formation with the terpene moiety, although Delta(9)-THCA has dibenzopyran ring structure. It was assumed that the whole structure of CBDA is important for COX-2 selective inhibition because beta-resorcylic acid itself did not inhibit COX-2 activity. Methylation of the carboxylic acid moiety of CBDA led to disappearance of COX-2 selectivity. Thus, it was suggested that the carboxylic acid moiety in CBDA is a key determinant for the inhibition. Furthermore, the crude extract of cannabis containing mainly CBDA was shown to have a selective inhibitory effect on COX-2. Taken together, these lines of evidence in this study suggest that naturally occurring CBDA in cannabis is a selective inhibitor for COX-2. PMID:18556441

Takeda, Shuso; Misawa, Koichiro; Yamamoto, Ikuo; Watanabe, Kazuhito

2008-09-01

219

Constitutive activation of AMPK ?1 in vascular endothelium promotes high-fat diet-induced fatty liver injury: role of COX-2 induction  

PubMed Central

Background and Purpose:?AMP-activated protein kinase (AMPK), an important regulator of energy metabolism, comprises three (?, ? and ?) subunits, each with a unique tissue distribution. As AMPK has a wide range of protein and gene targets, defining its role has been difficult. Here, we have studied a transgenic mouse model overexpressing the constitutively active ?1 subunit of AMPK in endothelial cells (EC-AMPK) to elucidate its role in energy homeostasis. Experimental Approach:?Wild-type and EC-AMPK mice were fed with a high fat diet for 16 weeks. Drugs (or vehicles) were given daily by oral gavage. Body weight, fat mass composition, glucose and lipid levels were monitored regularly. Tissues including aortae and liver were collected for quantitative RT-PCR, Western blotting, elisa, histological and biochemical evaluations. Key Results:?Compared with wild-type animals, high fat diet caused more severe metabolic defects in EC-AMPK mice, which exhibited increased body weight and fat mass, elevated blood pressure, augmented glucose and lipid levels, impaired glucose tolerance, hepatomegaly and steatohepatitis. Constitutive activation of AMPK ?1 in endothelial cells induced COX-2 expression and arterial inflammation. Genes involved in lipid metabolism were down-regulated in aortae and livers of EC-AMPK mice. Chronic treatment with selective COX-2 inhibitors, celecoxib or nimesulide, significantly ameliorated arterial inflammation, steatohepatitis and hyperlipidaemia in EC-AMPK mice, without altering their blood pressure or clotting. Conclusions and Implications:?Constitutive activation of endothelial AMPK ?1 promotes vascular inflammation and the development of obesity-induced fatty livers largely via induction of COX-2. PMID:24372551

Liang, Yan; Huang, Bosheng; Song, Erfei; Bai, Bo; Wang, Yu

2014-01-01

220

Parthenolide Inhibits Cancer Stem-Like Side Population of Nasopharyngeal Carcinoma Cells via Suppression of the NF-?B/COX-2 Pathway  

PubMed Central

Cancer stem cells play a central role in the pathogenesis of nasopharyngeal carcinoma and contribute to both disease initiation and relapse. In this study, cyclooxygenase-2 (COX-2) was found to regulate cancer stem-like side population cells of nasopharyngeal carcinoma cells and enhance cancer stem-like cells' characteristics such as higher colony formation efficiency and overexpression of stemness-associated genes. The regulatory effect of COX-2 on cancer stem-like characteristics may be mediated by ABCG2. COX-2 overexpression by a gain-of-function experiment increased the proportion of side population cells and their cancer stemness properties. The present study also demonstrated that in contrast to the classical chemotherapy drug 5-fluorouracil, which increased the proportion of side population cells and upregulated the expression of COX-2, parthenolide, a naturally occurring small molecule, preferentially targeted the side population cells of nasopharyngeal carcinoma cells and downregulated COX-2. Moreover, we found that the cancer stem-like cells' phenotype was suppressed by using COX-2 inhibitors NS-398 and CAY10404 or knocking down COX-2 with siRNA and shRNA. These findings suggest that COX-2 inhibition is the mechanism by which parthenolide induces cell death in the cancer stem-like cells of nasopharyngeal carcinoma. In addition, parthenolide exhibited an inhibitory effect on nuclear factor-kappa B (NF-?B) nucler translocation by suppressing both the phosphorylation of I?B kinase complex and I?B? degradation. Taken together, these results suggest that parthenolide may exert its cancer stem cell-targeted chemotherapy through the NF-?B/COX-2 pathway. PMID:25553117

Liao, Kun; Xia, Bin; Zhuang, Qun-Ying; Hou, Meng-Jun; Zhang, Yu-Jing; Luo, Bing; Qiu, Yang; Gao, Yan-Fang; Li, Xiao-Jie; Chen, Hui-Feng; Ling, Wen-Hua; He, Cheng-Yong; Huang, Yi-Jun; Lin, Yu-Chun; Lin, Zhong-Ning

2015-01-01

221

Hydroxycoumarins as selective MAO-B inhibitors.  

PubMed

A series of 3-aryl-4-hydroxycoumarin derivatives was synthesized with the aim to find out the structural features for the MAO inhibitory activity and selectivity. Methoxy and/or chloro substituents were introduced in the 3-phenyl ring, whereas the position 6 in the coumarin moiety was not substituted or substituted with a methyl group or a chloro atom due to their different electronic, steric and/or lipophilic properties. Most of the synthesized compounds presented MAO-B inhibitory activity. The presence of methoxy and chloro groups, respectively in the para and meta positions of the 3-phenyl ring, have an important influence on the inhibitory activity. Moreover, the presence of a chloro atom in the six position of the moiety (compound 7) improved the inhibitor activity as well as its selectivity against MAO-B compared with iproniazide, used as reference compound. Docking experiments were carried out to understand which are the most energetically preferred orientations adopted by compounds 5, 6 and 7 inside the MAO-B binding pocket. PMID:22137786

Serra, Silvia; Ferino, Giulio; Matos, Maria João; Vázquez-Rodríguez, Saleta; Delogu, Giovanna; Viña, Dolores; Cadoni, Enzo; Santana, Lourdes; Uriarte, Eugenio

2012-01-01

222

Expression of Human Papillomavirus is Correlated with Ki-67 and COX-2 Expressions in Keratocystic Odontogenic Tumor.  

PubMed

The aim of the current study was to investigate the presence of human papillomavirus (HPV) and evaluate its association with Ki-67 and cyclooxygenase-2 (COX-2) expressions in keratocystic odontogenic tumor (KCOT). Nineteen cases were included in the present study. Conventional PCR method and immunohistochemical analysis were performed for the detection of HPV-DNA and HPV-L1 capsid protein. Moreover, the expressions of Ki-67 and COX-2 proteins were analyzed immunohistochemically. HPV-DNA was detected in 36.8 % (7/19) of tumor samples, whilst HPV-L1 protein was identified in 68.4 % (13/19) of them. The Kappa coefficient statistical test showed a moderate agreement (??0.424) between PCR and IHC assays for HPV detection. Expression of HPV-DNA was positively correlated with Ki-67 and COX-2 expressions (p?COX-2 (p?COX-2 expression. These findings suggest that HPV may have a role in the pathogenesis and aggressiveness of KCOT. Based on these conclusions, we recommend further investigations of HPV vaccine or antiviral therapy and COX-2 inhibitors as nonsurgical options in the prevention and management of KCOT. PMID:24831259

Alsaegh, Mohammed Amjed; Miyashita, Hitoshi; Zhu, Sheng Rong

2015-01-01

223

Discovery of potent, selective sulfonylfuran urea endothelial lipase inhibitors.  

PubMed

Endothelial lipase (EL) activity has been implicated in HDL catabolism, vascular inflammation, and atherogenesis, and inhibitors are therefore expected to be useful for the treatment of cardiovascular disease. Sulfonylfuran urea 1 was identified in a high-throughput screening campaign as a potent and non-selective EL inhibitor. A lead optimization effort was undertaken to improve potency and selectivity, and modifications leading to improved LPL selectivity were identified. Radiolabeling studies were undertaken to establish the mechanism of action for these inhibitors, which were ultimately demonstrated to be irreversible inhibitors. PMID:19058966

Goodman, Krista B; Bury, Michael J; Cheung, Mui; Cichy-Knight, Maria A; Dowdell, Sarah E; Dunn, Allison K; Lee, Dennis; Lieby, Jeffrey A; Moore, Michael L; Scherzer, Daryl A; Sha, Deyou; Suarez, Dominic P; Murphy, Dennis J; Harpel, Mark R; Manas, Eric S; McNulty, Dean E; Annan, Roland S; Matico, Rosalie E; Schwartz, Benjamin K; Trill, John J; Sweitzer, Thomas D; Wang, Da-Yuan; Keller, Paul M; Krawiec, John A; Jaye, Michael C

2009-01-01

224

Overexpression of cyclooxygenase-2 in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and mechanism of cyclooxygenase-2 selective inhibitor celecoxib-induced cell growth inhibition and apoptosis  

PubMed Central

AIM: To investigate the cyclooxygenase-2 (COX-2) expression level in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and the molecular mechanism of COX-2 selective inhibitor celecoxib-induced cell growth inhibition and cell apoptosis. METHODS: Hepatoma cells were cultured and treated with celecoxib. Cell in situ hybridization (ISH) and immunocytochemistry were used to detect COX-2 mRNA and protein expression. Proliferating cell nuclear antigen and phosphorylated Akt were also detected by immunocytochemistry assay. Cell growth rates were assessed by 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenylte-trazolium (MTT) bromide colorimetric assay. Celecoxib-induced cell apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and flow cytometry (FCM). The phosphorylated Akt and activated fragments of caspase-9, caspase-3 were examined by Western blotting analysis. RESULTS: Increased COX-2 mRNA and protein expression were detected in all three hepatoma cell lines. Celecoxib could significantly inhibit cell growth and the inhibitory effect was in a dose- and time-dependent manner evidenced by MTT assays and morphological changes. The apoptotic index measured by TUNEL increased correspondingly with the increased concentration of celecoxib and the reaction time. With 50 ?mol/L celecoxib treatment for 24 h, the apoptotic index of HepG2, BEL-7402 and SMMC-7721 cells was 25.01±3.08%, 26.40±3.05%, and 30.60±2.89%, respectively. Western blotting analysis showed remarkable activation of caspase-9, caspase-3 and dephosphorylation of Akt (Thr308). Immunocytochemistry also showed the reduction of PCNA expression and phosphorylation Akt (Thr308) after treatment with celecoxib. CONCLUSION: COX-2 mRNA and protein overexpression in HepG2, Bel-7402 and SMMC-7721 cell lines correlate with the increased cell growth rate. Celecoxib can inhibit proliferation and induce apoptosis of hepatoma cell strains in a dose- and time-dependent manner. PMID:16419156

Liu, Ning-Bo; Peng, Tao; Pan, Chao; Yao, Yu-Yu; Shen, Bo; Leng, Jing

2005-01-01

225

Novel lignan derivatives as selective inhibitors of DNA topoisomerase II  

Microsoft Academic Search

Rabdosiin (1) and its isomer (2), isolated from Arnebia euchroma, were potent non-selective inhibitors of mammalian DNA topoisomerases in vitro. Evaluation of synthetic analogs led to the discovery of 3 – 5 as selective inhibitors of topoisomerase II. Unlike etoposide, which inhibits by preventing the DNA rejoining process, compounds 1 – 5 did not induce DNA breakage in either cellular

Yoshiki Kashiwada; Kenneth F. Bastow; Kuo-Hsiung Lee

1995-01-01

226

Effects of COX-2 inhibition on spinal nociception: the role of endocannabinoids  

PubMed Central

Background and purpose: Recent studies suggest that the effects of cyclooxygenase-2 (COX-2) inhibition are mediated by cannabinoid receptor activation. However, some non-steroidal anti-inflammatory drugs inhibit the enzyme fatty acid amide hydrolase, which regulates levels of some endocannabinoids. Whether COX-2 directly regulates levels of endocannabinoids in vivo is unclear. Here, the effect of the COX-2 inhibitor nimesulide, which does not inhibit fatty acid amide hydrolase, on spinal nociceptive processing was determined. Effects of nimesulide on tissue levels of endocannabinoids and related compounds were measured and the role of cannabinoid 1 (CB1) receptors was determined. Experimental approach: Effects of spinal and peripheral administration of nimesulide (1–100 µg per 50 µL) on mechanically evoked responses of rat dorsal horn neurones were measured, and the contribution of the CB1 receptor was determined with the antagonist AM251 (N-(piperidin-1-yl)-5-(-4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide), in anaesthetized rats. Effects of nimesulide on spinal levels of endocannabinoids and related compounds were quantified using liquid chromatography-tandem mass spectrometry. Key results: Spinal, but not peripheral, injection of nimesulide (1–100 µg per 50 µL) significantly reduced mechanically evoked responses of dorsal horn neurones. Inhibitory effects of spinal nimesulide were blocked by the CB1 receptor antagonist AM251 (1 µg per 50 µL), but spinal levels of endocannabinoids were not elevated. Indeed, both anandamide and N-oleoylethanolamide (OEA) were significantly decreased by nimesulide. Conclusions and implications: Although the inhibitory effects of COX-2 blockade on spinal neuronal responses by nimesulide were dependent on CB1 receptors, we did not detect a concomitant elevation in anandamide or 2-AG. Further understanding of the complexities of endocannabinoid catabolism by multiple enzymes is essential to understand their contribution to COX-2-mediated analgesia. This article is part of a themed issue on Cannabinoids. To view the editorial for this themed issue visit http://dx.doi.org/10.1111/j.1476-5381.2010.00831.x PMID:20590570

Staniaszek, LE; Norris, LM; Kendall, DA; Barrett, DA; Chapman, V

2010-01-01

227

Treatment of selective mutism: focus on selective serotonin reuptake inhibitors.  

PubMed

Abstract Selective mutism is a pediatric psychiatric disorder that occurs when a child consistently fails to speak in specific situations in which speaking is expected, such as at school and social gatherings, but speaks appropriately in other settings. Selective mutism often is diagnosed when a child starts school and does not talk to teachers or peers, but talks to family members at home; the condition is frequently accompanied by anxiety and shyness. Although the underlying etiology of the condition remains unclear, psychotherapy is the preferred initial treatment, with the support of parents and teachers. If the child does not respond to psychotherapy, addition of pharmacologic treatment should be considered, depending on the severity of symptoms and presence of other illnesses. Although data are limited to case reports and trials with small patient populations and short follow-up periods, some patients with selective mutism respond to therapy with selective serotonin reuptake inhibitors (SSRIs). Fluoxetine is the most studied SSRI as treatment for the condition, although further investigation is required to determine the optimal dosage and duration of therapy. PMID:18225967

Kaakeh, Yaman; Stumpf, Janice L

2008-02-01

228

Cell-type-specific roles for COX-2 in UVB-induced skin cancer.  

PubMed

In human tumors, and in mouse models, cyclooxygenase-2 (COX-2) levels are frequently correlated with tumor development/burden. In addition to intrinsic tumor cell expression, COX-2 is often present in fibroblasts, myofibroblasts and endothelial cells of the tumor microenvironment, and in infiltrating immune cells. Intrinsic cancer cell COX-2 expression is postulated as only one of many sources for prostanoids required for tumor promotion/progression. Although both COX-2 inhibition and global Cox-2 gene deletion ameliorate ultraviolet B (UVB)-induced SKH-1 mouse skin tumorigenesis, neither manipulation can elucidate the cell type(s) in which COX-2 expression is required for tumorigenesis; both eliminate COX-2 activity in all cells. To address this question, we created Cox-2(flox/flox) mice, in which the Cox-2 gene can be eliminated in a cell-type-specific fashion by targeted Cre recombinase expression. Cox-2 deletion in skin epithelial cells of SKH-1 Cox-2(flox/flox);K14Cre(+) mice resulted, following UVB irradiation, in reduced skin hyperplasia and increased apoptosis. Targeted epithelial cell Cox-2 deletion also resulted in reduced tumor incidence, frequency, size and proliferation rate, altered tumor cell differentiation and reduced tumor vascularization. Moreover, Cox-2(flox/flox);K14Cre(+) papillomas did not progress to squamous cell carcinomas. In contrast, Cox-2 deletion in SKH-1 Cox-2(flox/flox); LysMCre(+) myeloid cells had no effect on UVB tumor induction. We conclude that (i) intrinsic epithelial COX-2 activity plays a major role in UVB-induced skin cancer, (ii) macrophage/myeloid COX-2 plays no role in UVB-induced skin cancer and (iii) either there may be another COX-2-dependent prostanoid source(s) that drives UVB skin tumor induction or there may exist a COX-2-independent pathway(s) to UVB-induced skin cancer. PMID:24469308

Jiao, Jing; Mikulec, Carol; Ishikawa, Tomo-o; Magyar, Clara; Dumlao, Darren S; Dennis, Edward A; Fischer, Susan M; Herschman, Harvey

2014-06-01

229

Evaluation of loxoprofen and its alcohol metabolites for potency and selectivity of inhibition of cyclooxygenase-2.  

PubMed

Loxoprofen, its trans-alcohol and cis-alcohol metabolites were evaluated for selectivity of inhibition of COX-2 over COX-1. The (2S,1'R,2'S)-trans-alcohol derivative was found to be the most active metabolite and to be a potent and nonselective inhibitor of COX-2 and COX-1 in both enzyme and human whole blood assays. PMID:14980665

Riendeau, Denis; Salem, Myriam; Styhler, Angela; Ouellet, Marc; Mancini, Joseph A; Li, Chun Sing

2004-03-01

230

A high level of cyclooxygenase-2 inhibitor selectivity is associated with a reduced interference of platelet cyclooxygenase-1 inactivation by aspirin.  

PubMed

Both nonsteroidal anti-inflammatory drugs, such as ibuprofen, and the prototypical selective cyclooxygenase (Cox)-2 inhibitors DuP-697 and NS-398 block the inhibition of Cox-1 by aspirin in vitro. However, clinical studies have shown that the Cox-2 selective drugs (or coxibs) rofecoxib and etoricoxib, at therapeutic doses, do not interfere with the antiplatelet effect of aspirin, in contrast to ibuprofen. Here, we have evaluated the relative potential of ibuprofen and various coxibs to interfere with the inactivation of Cox-1 by aspirin by using purified enzyme and calcium ionophore-activated human platelets. The irreversible inactivation of Cox-1 by aspirin can be antagonized by ibuprofen and coxibs, albeit with widely different potencies. The rank order of potencies for this process (ibuprofen > celecoxib > valdecoxib > rofecoxib > etoricoxib) parallels that obtained for the inhibition of Cox-1-mediated thromboxane B(2) production by calcium ionophore-stimulated platelets. The antagonism of aspirin therefore likely involves a competition at the enzyme active site. The EC(50) value for the antagonism against 10 microM aspirin for each drug is approximately 10- to 40-fold lower than the corresponding IC(50) value for inhibition of platelet Cox-1 activity, consistent with the much weaker initial binding of aspirin to Cox-1 as compared with arachidonic acid. These results show that a low affinity for Cox-1 and a high degree of Cox-2 selectivity confers a low potential to block aspirin inhibition of platelet Cox-1, consistent with the results of clinical studies. PMID:11717412

Ouellet, M; Riendeau, D; Percival, M D

2001-12-01

231

ATP Mediates NADPH Oxidase/ROS Generation and COX-2/PGE2 Expression in A549 Cells: Role of P2 Receptor-Dependent STAT3 Activation  

PubMed Central

Background Up-regulation of cyclooxygenase (COX)-2 and its metabolite prostaglandin E2 (PGE2) are frequently implicated in lung inflammation. Extracellular nucleotides, such as ATP have been shown to act via activation of P2 purinoceptors, leading to COX-2 expression in various inflammatory diseases, such as lung inflammation. However, the mechanisms underlying ATP-induced COX-2 expression and PGE2 release remain unclear. Principal Findings Here, we showed that ATP?S induced COX-2 expression in A549 cells revealed by western blot and real-time PCR. Pretreatment with the inhibitors of P2 receptor (PPADS and suramin), PKC (Gö6983, Gö6976, Ro318220, and Rottlerin), ROS (Edaravone), NADPH oxidase [diphenyleneiodonium chloride (DPI) and apocynin], Jak2 (AG490), and STAT3 [cucurbitacin E (CBE)] and transfection with siRNAs of PKC?, PKC?, PKC?, p47phox, Jak2, STAT3, and cPLA2 markedly reduced ATP?S-induced COX-2 expression and PGE2 production. In addition, pretreatment with the inhibitors of P2 receptor attenuated PKCs translocation from the cytosol to the membrane in response to ATP?S. Moreover, ATP?S-induced ROS generation and p47phox translocation was also reduced by pretreatment with the inhibitors of P2 receptor, PKC, and NADPH oxidase. On the other hand, ATP?S stimulated Jak2 and STAT3 activation which were inhibited by pretreatment with PPADS, suramin, Gö6983, Gö6976, Ro318220, GF109203X, Rottlerin, Edaravone, DPI, and apocynin in A549 cells. Significance Taken together, these results showed that ATP?S induced COX-2 expression and PGE2 production via a P2 receptor/PKC/NADPH oxidase/ROS/Jak2/STAT3/cPLA2 signaling pathway in A549 cells. Increased understanding of signal transduction mechanisms underlying COX-2 gene regulation will create opportunities for the development of anti-inflammation therapeutic strategies. PMID:23326583

Cheng, Shin-Ei; Lee, I-Ta; Lin, Chih-Chung; Wu, Wan-Ling; Hsiao, Li-Der; Yang, Chuen-Mao

2013-01-01

232

Structure-based design of cyclooxygenase-2 selectivity into ketoprofen.  

PubMed

We have recently described how to achieve COX-2 selectivity from the non-selective inhibitor indomethacin (1) using a combination of a pharmacophore and computer 3-D models based on the known X-ray crystal structures of cyclooxygenases. In the present study we have focused on the design of COX-2 selective analogues of the NSAID ketoprofen (2). The design is similarly based on the combined use of the previous pharmacophore together with traditional medicinal chemistry techniques motivated by the comparative modeling of the 3-D structures of 2 docked into the COX active sites. The analysis includes use of the program GRID to detect isoenzyme differences near the active site region and is aimed at suggesting modifications of the basic benzophenone frame of the lead compound 2. The resulting series of compounds bearing this central framework is exemplified by the potent and selective COX-2 inhibitor 17 (LM-1669). PMID:11844666

Palomer, Albert; Pascual, Jaume; Cabré, Marta; Borràs, Liset; González, Gracia; Aparici, Mònica; Carabaza, Assumpta; Cabré, Francesc; García, M Luisa; Mauleón, David

2002-02-25

233

Inhibition of COX1 activity and COX2 expression by 3-(4?-geranyloxy-3?-methoxyphenyl)-2- trans propenoic acid and its semi-synthetic derivatives  

Microsoft Academic Search

Oxyprenylated naturally occurring cinnamic acids displayed efficient and promising biological activities. Aim of this study was to characterize the effects of 3-(4?-geranyl-3?-methoxy)phenyl-2-trans propenoic acid and its selected semi-synthetic analogues, on COX-2 expression and activity, and on COX-1 activity, in purified systems or in whole cell systems. The anti-inflammatory activity of title compounds (1) was tested as inhibition of COX-2 on

Salvatore Genovese; Massimo Curini; Paolo Gresele; Teresa Corazzi; Francesco Epifano

2011-01-01

234

Ligand activation of peroxisome proliferator-activated receptor-beta/delta (PPARbeta/delta) and inhibition of cyclooxygenase 2 (COX2) attenuate colon carcinogenesis through independent signaling mechanisms.  

PubMed

Cyclooxygenase (COX) 2-derived prostaglandin E(2) (PGE(2)) promotes colorectal carcinoma growth and invasion, and inhibition of COX2 by non-steroidal anti-inflammatory drugs is known to inhibit these processes. There is controversy regarding the effect of ligand activation of peroxisome proliferator-activated receptor (PPAR)-beta/delta on colon carcinogenesis, although collective evidence from independent laboratories suggest that ligand activation of PPARbeta/delta leads to the induction of terminal differentiation coupled with inhibition of cell growth in a variety of models. The present study examined the hypothesis that ligand activation of PPARbeta/delta and inhibition of COX2 attenuate colon cancer through independent mechanisms and that combining these two mechanisms will enhance this inhibition. Colon cancer was induced by administering azoxymethane to wild-type and PPARbeta/delta-null mice. Cohorts of mice were treated with GW0742 (a PPARbeta/delta ligand), nimesulide (a COX2 inhibitor) or a combination of GW0742 and nimesulide. Inhibition of COX2 by nimesulide attenuated colon cancer and ligand activation of PPARbeta/delta by GW0742 had inhibitory effects. However, the combined treatment of GW0742 and nimesulide did not cause an enhancement in the attenuation of colon cancer. Mechanistically, the effects of these compounds occurred through independent mechanisms as increased levels of differentiation markers as a result of ligand activation of PPARbeta/delta were not found with COX2 inhibition, and a reduction in PGE(2) levels resulting from COX2 inhibition was not observed in response to ligand activation of PPARbeta/delta. Results from these studies effectively dissociate COX2 inhibition and PPARbeta/delta activity during colon carcinogenesis. PMID:17893232

Hollingshead, Holly E; Borland, Michael G; Billin, Andrew N; Willson, Timothy M; Gonzalez, Frank J; Peters, Jeffrey M

2008-01-01

235

Discovery of cyclooxygenase inhibitors from medicinal plants used to treat inflammation  

PubMed Central

Eleven authenticated botanicals used in the traditional Chinese medicine Huo-Luo-Xiao-Ling Dan were screened for ligands to cyclooxygenase (COX) using pulsed ultrafiltration liquid chromatography-mass spectrometry, and a mass spectrometry-based enzyme assay was used to determine the concentration of each of 17 ligands that inhibited COX-1 or COX-2 by 50% (IC50). Acetyl-11-keto-?-boswellic -boswellic acid, acid, acetyl-?-boswellic acid, acetyl-?-boswellic acid, and betulinic acid were COX-1 selective inhibitors with IC50 values of approximately 10 ?M. Senkyunolide O and cryptotanshinone were COX-2 selective inhibitors with IC50 values of 5 and 22 ?M, respectively. Roburic acid and phenethyl-trans-ferulate inhibited COX-1 and COX-2 equally. COX inhibition and the IC50 values of most of these natural product ligands have not been reported previously. PMID:20188172

Cao, Hongmei; Yu, Rui; Choi, Yongsoo; Ma, Zhong-Ze; Zhang, Hongjie; Xiang, Wei; Lee, David Yue-Wei; Berman, Brian M.; Moudgil, Kamal D; Fong, Harry H.S.; van Breemen, Richard B.

2010-01-01

236

Discovery of cyclooxygenase inhibitors from medicinal plants used to treat inflammation.  

PubMed

Eleven authenticated botanicals used in the traditional Chinese medicine Huo-Luo-Xiao-Ling Dan were screened for ligands to cyclooxygenase (COX) using pulsed ultrafiltration liquid chromatography-mass spectrometry, and a mass spectrometry-based enzyme assay was used to determine the concentration of each of 17 ligands that inhibited COX-1 or COX-2 by 50% (IC(50)). Acetyl-11-keto-beta-boswellic acid, beta-boswellic acid, acetyl-alpha-boswellic acid, acetyl-beta-boswellic acid, and betulinic acid were COX-1 selective inhibitors with IC(50) values of approximately 10 microM. Senkyunolide O and cryptotanshinone were COX-2 selective inhibitors with IC(50) values of 5 microM and 22 microM, respectively. Roburic acid and phenethyl-trans-ferulate inhibited COX-1 and COX-2 equally. COX inhibition and the IC(50) values of most of these natural product ligands have not been reported previously. PMID:20188172

Cao, Hongmei; Yu, Rui; Choi, Yongsoo; Ma, Zhong-Ze; Zhang, Hongjie; Xiang, Wei; Lee, David Yue-Wei; Berman, Brian M; Moudgil, Kamal D; Fong, Harry H S; van Breemen, Richard B

2010-06-01

237

Artesunate Induces Apoptosis of Bladder Cancer Cells by miR-16 Regulation of COX-2 Expression  

PubMed Central

Bladder cancer is the most common malignant tumor of the urinary tract and remains one of the major causes of cancer death worldwide. In this study, we investigated the effect and mechanism of Artesunate (ART), a traditional Chinese medicine, on inducing apoptosis of human bladder cancer cells. In vivo antitumor activity was investigated in bladder cancer in rat by subcutaneous injection of different concentration of ART. The effect of ART on growth inhibition and apoptosis of bladder cancer cells was evaluated using dimethylthiazoly-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. Cyclooxygenase-2 (COX-2) and miR-16 expression levels were determined with real-time PCR. The concentrations of prostaglandin E2 (PGE2) in the supernatants of bladder cancer cells were measured with an ELISA kit. The miR-16 inhibitor or mimic were transfected into cells to up- or down-regulate miR-16 expression. ART efficiently inhibited orthotopic tumor growth in the bladder cancer rat, which is accompanied with an increase of miR-16 expression and a decrease of COX-2 expression. In vitro, ART could induce cytotoxicity and apoptosis in bladder cancer cells, but presented a much lighter toxicity effect against normal human urothelial cells. ART significantly increased miR-16 expression and decreased the expression of COX-2 and the production of PGE2. More importantly, down-regulation of miR-16 expression could reverse the effect of ART on apoptosis and COX-2 expression in bladder cells. Moreover, exogenous PGE2 could inhibit apoptosis of bladder cancer cells treated with ART. In conclusion, ART can elicit an anti-tumor effect against bladder cancer by up-regulation of miR-16 expression, which resulted in the decrease of COX-2 expression and PGE2 production. Hence, ART might be an effective drug for the treatment of bladder cancer. PMID:25196524

Zuo, Wei; Wang, Zhen-Zhong; Xue, Jun

2014-01-01

238

Caffeic acid, a phenolic phytochemical in coffee, directly inhibits Fyn kinase activity and UVB-induced COX-2 expression  

PubMed Central

Caffeic acid (3,4-dihydroxycinnamic acid) is a well-known phenolic phytochemical present in many foods, including coffee. Recent studies suggested that caffeic acid exerts anticarcinogenic effects, but little is known about the underlying molecular mechanisms and specific target proteins. In this study, we found that Fyn, one of the members of the non-receptor protein tyrosine kinase family, was required for ultraviolet (UV) B-induced cyclooxygenase-2 (COX-2) expression, and caffeic acid suppressed UVB-induced skin carcinogenesis by directly inhibiting Fyn kinase activity. Caffeic acid more effectively suppressed UVB-induced COX-2 expression and subsequent prostaglandin E2 production in JB6 P+ mouse skin epidermal (JB6 P+) cells compared with chlorogenic acid (5-O-caffeoylquinic acid), an ester of caffeic acid with quinic acid. Data also revealed that caffeic acid more effectively induced the downregulation of COX-2 expression at the transcriptional level mediated through the inhibition of activator protein-1 (AP-1) and nuclear factor-?B transcription activity compared with chlorogenic acid. Fyn kinase activity was suppressed more effectively by caffeic acid than by chlorogenic acid, and downstream mitogen-activated protein kinases (MAPKs) were subsequently blocked. Pharmacological Fyn kinase inhibitor (3-(4-chlorophenyl)1-(1,1-dimethylethyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine and leflunomide) data also revealed that Fyn is involved in UVB-induced COX-2 expression mediated through the phosphorylation of MAPKs in JB6 P+ cells. Pull-down assays revealed that caffeic acid directly bound with Fyn and non-competitively with adenosine triphosphate. In vivo data from mouse skin also supported the idea that caffeic acid suppressed UVB-induced COX-2 expression by blocking Fyn kinase activity. These results suggested that this compound could act as a potent chemopreventive agent against skin cancer. PMID:19073879

Kang, Nam Joo; Lee, Ki Won; Shin, Bong Jik; Jung, Sung Keun; Hwang, Mun Kyung; Bode, Ann M.; Heo, Yong-Seok; Dong, Zigang

2009-01-01

239

Development of a highly selective c-Src kinase inhibitor  

PubMed Central

Generating highly selective probes to interrogate protein kinase function in biological studies remains a challenge and new strategies are required. Herein, we describe the development of the first highly selective and cell permeable inhibitor of c-Src, a key signaling kinase in cancer. Our strategy involves extension of traditional inhibitor design by appending functionality proposed to interact with the phosphate-binding loop of c-Src. Using our selective inhibitor, we demonstrate that selective inhibition is significantly more efficacious than pan-kinase inhibition in slowing the growth of cancer cells. We also show that inhibition of c-Abl kinase, an off-target of most c-Src inhibitors, promotes oncogenic cell growth. PMID:22594480

Brandvold, Kristoffer R.; Steffey, Michael E.; Fox, Christel C.; Soellner, Matthew B.

2012-01-01

240

Development of a highly selective c-Src kinase inhibitor.  

PubMed

Generating highly selective probes to interrogate protein kinase function in biological studies remains a challenge, and new strategies are required. Herein, we describe the development of the first highly selective and cell-permeable inhibitor of c-Src, a key signaling kinase in cancer. Our strategy involves extension of traditional inhibitor design by appending functionality proposed to interact with the phosphate-binding loop of c-Src. Using our selective inhibitor, we demonstrate that selective inhibition is significantly more efficacious than pan-kinase inhibition in slowing the growth of cancer cells. We also show that inhibition of c-Abl kinase, an off-target of most c-Src inhibitors, promotes oncogenic cell growth. PMID:22594480

Brandvold, Kristoffer R; Steffey, Michael E; Fox, Christel C; Soellner, Matthew B

2012-08-17

241

Lung inflammation caused by adenosine-5'-triphosphate is mediated via Ca2+/PKCs-dependent COX-2/PGE2 induction.  

PubMed

Up-regulation of cyclooxygenase (COX)-2 and prostaglandin E2 (PGE2) are implicated in lung inflammation. Adenosine 5'-triphosphate (ATP) has been shown to act via activation of P2 purinoceptors, leading to COX-2 expression in various inflammatory diseases. The mechanisms of ATP-induced COX-2 expression and PGE2 release remain unclear. We showed that pretreatment with the inhibitors of P2 receptors (PPADS and Suramin), Gq protein (GPA2A), phosphatidylcholine-phospholipase C (PC-PLC; D609), phosphoinositide-phospholipase C (PI-PLC; ET-18-OCH3), Ca(2+)/calmodulin-dependent protein kinase II (CaMKII; KN62), protein kinase C (PKC; Gö6976, Ro-318220, GF109203X, and rottlerin), MEK1/2 (PD98059), p38 MAPK (SB202190), and nuclear factor-kappaB (NF-?B; Bay11-7082) and the intracellular calcium chelator (BAPTA/AM) or transfection with siRNAs of these molecules and cPLA2 reduced ATP?S-induced COX-2 expression or PGE2 production in A549 cells. In addition, ATP?S-induced elevation of intracellular Ca(2+) concentration was attenuated by PPADS, Suramin, D609, or ET-18-OCH3. ATP?S-induced p38 MAPK, p42/p44 MAPK, and NF-?B p65 activation were inhibited by Gö6976, Ro-318220, GF109203X, or rottlerin. ATP?S also induced cPLA2 phosphorylation and activity, which were reduced via inhibition of P2 receptors, PKCs, p38 MAPK, and p42/p44 MAPK. ATP?S-induced cPLA2 expression was inhibited by SB202190, PD98059, or Bay11-7082. In the in vitro study, we established that ATP?S induced PGE2 generation via a cPLA2/COX-2-dependent pathway. In the in vivo study, we found that ATP?S induced COX-2 mRNA expression in the lungs and leukocyte (mainly eosinophils and neutrophils) count in bronchoalveolar lavage (BAL) fluid in mice via a P2 receptors-dependent signaling pathway. We concluded that ATP?S may induce lung inflammation via a cPLA2/COX-2/PGE2-dependent pathway. PMID:23680674

Lee, I-Ta; Lin, Chih-Chung; Lin, Wei-Ning; Wu, Wan-Ling; Hsiao, Li-Der; Yang, Chuen-Mao

2013-08-01

242

The Bradykinin B2 receptor is required for full expression of renal COX2 and renin  

Microsoft Academic Search

Angiotensin converting enzyme (ACE) inhibition leads to increased levels of bradykinin, cyclooxygenase-2 (COX-2), and renin. Since bradykinin stimulates prostaglandin release, renin synthesis may be regulated through a kinin-COX-2 pathway. To test this hypothesis, we examined the impact of bradykinin B2 receptor (B2R) gene disruption in mice on kidney COX-2 and renin gene expression. Kidney COX-2 mRNA and protein levels were

John D. Imig; Xueying Zhao; Sheyla R. Orengo; Susana Dipp; Samir S. El-Dahr

2003-01-01

243

Mono-, di-, and triaryl substituted tetrahydropyrans as cyclooxygenase-2 and tumor growth inhibitors. Synthesis and biological evaluation.  

PubMed

Rationally designed tetrahydropyrans (THPs) carrying one, two, or three aryl rings and other substituents were synthesized by the allylation of beta-hydroxy ketones followed by iodocyclization. It has been observed that compounds with one aryl ring on THP are moderate inhibitors of cyclooxygenase-1 (COX-1) (IC(50) = 0.3 microM) and cyclooxygenase-2 (IC(50) = 0.17 microM) with poor selectivity index (SI = 2-3) for COX-2. The presence of two aryl rings enhanced their inhibitory activities for COX-2 (IC(50) = 0.9-5.5 nM). Selectivity for COX-2 over COX-1 also increased (SI = 50-1900), while triaryl substituted THPs, along with high inhibition (IC(50) = 0.57-4.0 nM), also exhibited excellent selectivity for COX-2 over COX-1 (SI = 3200-44000). Similar to the experimental results of increased COX-2 inhibition and selectivity with the increase in the size of the molecule, their docking in the active sites of COX-1 and COX-2 also showed same trend. Seven compounds from the category of di- and triaryl substituted THPs exhibited average GI(50) over all the human tumor cell lines in the range 1.6-3.2 microM and showed in vitro therapeutic indices of 8-17. PMID:20387815

Singh, Palwinder; Bhardwaj, Atul

2010-05-13

244

Discovery and SAR of PF-4693627, a potent, selective and orally bioavailable mPGES-1 inhibitor for the potential treatment of inflammation.  

PubMed

Inhibition of mPGES-1, the terminal enzyme in the arachidonic acid/COX pathway to regulate the production of pro-inflammatory prostaglandin PGE2, is considered an attractive new therapeutic target for safe and effective anti-inflammatory drugs. The discovery of a novel series of orally active, selective benzoxazole piperidinecarboxamides as mPGES-1 inhibitors is described. Structure-activity optimization of lead 5 with cyclohexyl carbinols resulted in compound 12, which showed excellent in vitro potency and selectivity against COX-2, and reasonable pharmacokinetic properties. Further SAR studies of the benzoxazole ring substituents lead to a novel series of highly potent compounds with improved PK profile, including 23, 26, and 29, which were effective in a carrageenan-stimulated guinea pig air pouch model of inflammation. Based on its excellent in vitro and in vivo pharmacological, pharmacokinetic and safety profile and ease of synthesis, compound 26 (PF-4693627) was advanced to clinical studies. PMID:23260349

Arhancet, Graciela B; Walker, Daniel P; Metz, Sue; Fobian, Yvette M; Heasley, Steven E; Carter, Jeffrey S; Springer, John R; Jones, Darin E; Hayes, Michael J; Shaffer, Alexander F; Jerome, Gina M; Baratta, Michael T; Zweifel, Ben; Moore, William M; Masferrer, Jaime L; Vazquez, Michael L

2013-02-15

245

miR-143 decreases COX-2 mRNA stability and expression in pancreatic cancer cells  

SciTech Connect

Highlights: •Pancreatic cancer cells express low miR-143 levels and elevated p-MEK, p-MAPK and RREB1. •MEK inhibitors U0126 and PD98059 increase miR-143 expression. •miR-143 decreases COX-2 mRNA stability and expression and PGE{sub 2}. •miR-143 decreases p-p38MAPK, p-MEK, p-MAPK and RREB1 expression. -- Abstract: Small non-coding RNAs, microRNAs (miRNA), inhibit the translation or accelerate the degradation of message RNA (mRNA) by targeting the 3?-untranslated region (3?-UTR) in regulating growth and survival through gene suppression. Deregulated miRNA expression contributes to disease progression in several cancers types, including pancreatic cancers (PaCa). PaCa tissues and cells exhibit decreased miRNA, elevated cyclooxygenase (COX)-2 and increased prostaglandin E{sub 2} (PGE{sub 2}) resulting in increased cancer growth and metastases. Human PaCa cell lines were used to demonstrate that restoration of miRNA-143 (miR-143) regulates COX-2 and inhibits cell proliferation. miR-143 were detected at fold levels of 0.41 ± 0.06 in AsPC-1, 0.20 ± 0.05 in Capan-2 and 0.10 ± 0.02 in MIA PaCa-2. miR-143 was not detected in BxPC-3, HPAF-II and Panc-1 which correlated with elevated mitogen-activated kinase (MAPK) and MAPK kinase (MEK) activation. Treatment with 10 ?M of MEK inhibitor U0126 or PD98059 increased miR-143, respectively, by 187 ± 18 and 152 ± 26-fold in BxPC-3 and 182 ± 7 and 136 ± 9-fold in HPAF-II. miR-143 transfection diminished COX-2 mRNA stability at 60 min by 2.6 ± 0.3-fold in BxPC-3 and 2.5 ± 0.2-fold in HPAF-II. COX-2 expression and cellular proliferation in BxPC-3 and HPAF-II inversely correlated with increasing miR-143. PGE{sub 2} levels decreased by 39.3 ± 5.0% in BxPC-3 and 48.0 ± 3.0% in HPAF-II transfected with miR-143. Restoration of miR-143 in PaCa cells suppressed of COX-2, PGE{sub 2}, cellular proliferation and MEK/MAPK activation, implicating this pathway in regulating miR-143 expression.

Pham, Hung [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States) [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States); Department of Medicine, Veterans Affair Greater Los Angeles Healthcare System, Los Angeles, CA 90073 (United States); Ekaterina Rodriguez, C.; Donald, Graham W.; Hertzer, Kathleen M.; Jung, Xiaoman S.; Chang, Hui-Hua; Moro, Aune; Reber, Howard A.; Hines, O. Joe [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States)] [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States); Eibl, Guido, E-mail: geibl@mednet.ucla.edu [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States)] [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States)

2013-09-13

246

Screening of selective histone deacetylase inhibitors by proteochemometric modeling  

PubMed Central

Background Histone deacetylase (HDAC) is a novel target for the treatment of cancer and it can be classified into three classes, i.e., classes I, II, and IV. The inhibitors selectively targeting individual HDAC have been proved to be the better candidate antitumor drugs. To screen selective HDAC inhibitors, several proteochemometric (PCM) models based on different combinations of three kinds of protein descriptors, two kinds of ligand descriptors and multiplication cross-terms were constructed in our study. Results The results show that structure similarity descriptors are better than sequence similarity descriptors and geometry descriptors in the leftacterization of HDACs. Furthermore, the predictive ability was not improved by introducing the cross-terms in our models. Finally, a best PCM model based on protein structure similarity descriptors and 32-dimensional general descriptors was derived (R2 = 0.9897, Qtest2 = 0.7542), which shows a powerful ability to screen selective HDAC inhibitors. Conclusions Our best model not only predict the activities of inhibitors for each HDAC isoform, but also screen and distinguish class-selective inhibitors and even more isoform-selective inhibitors, thus it provides a potential way to discover or design novel candidate antitumor drugs with reduced side effect. PMID:22913517

2012-01-01

247

Triazaspirodimethoxybenzoyls as Selective Inhibitors of Mycobacterial Lipoamide Dehydrogenase  

SciTech Connect

Mycobacterium tuberculosis (Mtb) remains the leading single cause of death from bacterial infection. Here we explored the possibility of species-selective inhibition of lipoamide dehydrogenase (Lpd), an enzyme central to Mtb's intermediary metabolism and antioxidant defense. High-throughput screening of combinatorial chemical libraries identified triazaspirodimethoxybenzoyls as high-nanomolar inhibitors of Mtb's Lpd that were noncompetitive versus NADH, NAD{sup +}, and lipoamide and >100-fold selective compared to human Lpd. Efficacy required the dimethoxy and dichlorophenyl groups. The structure of an Lpd-inhibitor complex was resolved to 2.42 {angstrom} by X-ray crystallography, revealing that the inhibitor occupied a pocket adjacent to the Lpd NADH/NAD{sup +} binding site. The inhibitor did not overlap with the adenosine moiety of NADH/NAD{sup +} but did overlap with positions predicted to bind the nicotinamide rings in NADH and NAD{sup +} complexes. The dimethoxy ring occupied a deep pocket adjacent to the FAD flavin ring where it would block coordination of the NADH nicotinamide ring, while the dichlorophenyl group occupied a more exposed pocket predicted to coordinate the NAD{sup +} nicotinamide. Several residues that are not conserved between the bacterial enzyme and its human homologue were predicted to contribute both to inhibitor binding and to species selectivity, as confirmed for three residues by analysis of the corresponding mutant Mtb Lpd proteins. Thus, nonconservation of residues lining the electron-transfer tunnel in Mtb Lpd can be exploited for development of species-selective Lpd inhibitors.

Bryk, Ruslana; Arango, Nancy; Venugopal, Aditya; Warren, J. David; Park, Yun-Hee; Patel, Mulchand S.; Lima, Christopher D.; Nathan, Carl (Weill-Med); (SKI); (SUNYB)

2010-06-25

248

TNF-? and LPA promote synergistic expression of COX-2 in human colonic myofibroblasts: role of LPA-mediated transactivation of upregulated EGFR  

PubMed Central

Background Enhanced EGF receptor (EGFR) signaling is a hallmark of many human cancers, though the role of enhanced EGFR signaling within the surrounding tumor stroma has not been well studied. The myofibroblast is an important stromal cell that demonstrates enhanced EGFR expression in the setting of inflammation, though the functional relevance is not known. We recently reported that TNF-? and the G protein-coupled receptor (GPCR) agonist lysophosphatidic acid (LPA) lead to synergistic cyclo-oxygenase-2 (COX-2) expression, an enzyme strongly associated with the development of colitis-associated cancer. Here, we investigate whether EGFR signaling plays a role in the synergistic COX-2 expression induced by LPA and TNF-?. Methods 18Co cells, a model of human colonic myofibroblasts, were grown to confluence on 35?×?10mm cell culture dishes and were used from passages 10–14. 18Co cells were treated with TNF-? (8.3 ng/ml) and LPA (10 ?M). EGFR and COX-2 protein expression, Y1068 phosphorylation, and p42/44 MAPK phosphorylation were assessed by Western Blot, in the presence and absence of various inhibitors. Results Exposure of 18Co cells to either TNF-? or LPA alone had no effect on EGFR autophosphorylation at Y1068. However, chronic exposure to TNF-? led to upregulation of EGFR in association with sustained LPA-mediated EGFR phosphorylation at Y1068. TNF-? and LPA also led to sustained p42/44 MAPK phosphorylation and synergistic COX-2 expression, effects that were partially inhibited by the EGFR tyrosine kinase inhibitor AG1478. p42/44 MAPK phosphorylation and COX-2 expression were inhibited to the same degree by the MMP inhibitors GM6001 and BB-94, suggesting that LPA-mediated EGFR transactivation involved MMP-mediated release of EGFR ligands from the cell surface. The Src inhibitor SU6556 inhibited TNF-?/LPA-mediated EGFR phosphorylation at Y1068, p42/44 MAPK phosphorylation, and COX-2 expression in a dose-dependent fashion, suggesting an upstream role of Src in the transactivation of EGFR. Conclusion Synergistic COX-2 expression induced by TNF-? and LPA involves Src/MMP-mediated transactivation of EGFR and downstream p42/44 MAPK activation in human colonic myofibroblasts. Enhanced EGFR expression induced by TNF-? promotes GPCR-mediated EGFR transactivation in colonic myofibroblasts, providing an important mechanism for stromal COX-2 over-expression that may predispose to the development of colitis-associated cancer. PMID:23688423

2013-01-01

249

Identification and absolute configuration of dihydroxy-arachidonic acids formed by oxygenation of 5S-HETE by native and aspirin-acetylated COX-2  

PubMed Central

Biosynthesis of the prostaglandin endoperoxide by the cyclooxygenase (COX) enzymes is accompanied by formation of a small amount of 11R-hydroxyeicosatetraenoic acid (HETE), 15R-HETE, and 15S-HETE as by-products. Acetylation of COX-2 by aspirin abrogates prostaglandin synthesis and triggers formation of 15R-HETE as the sole product of oxygenation of arachidonic acid. Here, we investigated the formation of by-products of the transformation of 5S-HETE by native COX-2 and by aspirin-acetylated COX-2 using HPLC-ultraviolet, GC-MS, and LC-MS analysis. 5S,15S- dihydroxy (di)HETE, 5S,15R-diHETE, and 5S,11R-diHETE were identified as by-products of native COX-2, in addition to the previously described di-endoperoxide (5S,15S-dihydroxy-9S,11R,8S,12S-diperoxy-6E,13E-eicosadienoic acid) as the major oxygenation product. 5S,15R-diHETE was the only product formed by aspirin-acetylated COX-2. Both 5,15-diHETE and 5,11-diHETE were detected in CT26 mouse colon carcinoma cells as well as in lipopolysaccharide-activated RAW264.7 cells incubated with 5S-HETE, and their formation was attenuated in the presence of the COX-2 specific inhibitor, NS-398. Aspirin-treated CT26 cells gave 5,15-diHETE as the most prominent product formed from 5S-HETE. 5S,15S-diHETE has been described as a product of the cross-over of 5-lipoxygenase (5-LOX) and 15-LOX activities in elicited rat mononuclear cells and human leukocytes, and our studies implicate cross-over of the 5-LOX and COX-2 pathways as an additional biosynthetic route. PMID:19752399

Mulugeta, Surafel; Suzuki, Takashi; Hernandez, Noemi Tejera; Griesser, Markus; Boeglin, William E.; Schneider, Claus

2010-01-01

250

Fragment-based discovery of novel and selective mPGES-1 inhibitors Part 1: identification of sulfonamido-1,2,3-triazole-4,5-dicarboxylic acid.  

PubMed

Microsomal prostaglandin E synthase-1 (mPGES-1) is an inducible prostaglandin E synthase that catalyzes the conversion of prostaglandin PGH(2) to PGE(2) and represents a novel target for therapeutic treatment of inflammatory disorders. It is essential to identify mPGES-1 inhibitor with novel scaffold as new hit or lead compound for the purpose of the next-generation anti-inflammatory drugs. Herein we report the discovery of sulfonamido-1,2,3-triazole-4,5-dicarboxylic derivatives as a novel class of mPGES-1 inhibitors identified through fragment-based virtual screening and in vitro assays on the inhibitory activity of the actual compounds. 1-[2-(N-Phenylbenzenesulfonamido)ethyl]-1H-1,2,3-triazole-4,5-dicarboxylic acid (6f) inhibits human mPGES-1 (IC(50) of 1.1 ?M) with high selectivity (ca.1000-fold) over both COX-1 and COX-2 in a cell-free assay. In addition, the activity of compound 6f was again tested at 10 ?M concentration in presence of 0.1% Triton X-100 and found to be reduced to 1/4 of its original activity without this detergent. Compared to the complete loss of activity of nuisance inhibitor with the detergent, therefore, compound 6f would be regarded as a partial nuisance inhibitor of mPGES-1 with a novel scaffold for the optimal design of more potent mPGES-1 inhibitors. PMID:23218602

Lee, Kijae; Pham, Van Chung; Choi, Min Ji; Kim, Kyung Ju; Lee, Kyung-Tae; Han, Seong-Gu; Yu, Yeon Gyu; Lee, Jae Yeol

2013-01-01

251

Characterization of isoenzyme-selective inhibitors of human sphingosine kinases.  

PubMed

Sphingosine kinases (SKs) are promising new therapeutic targets for cancer because they regulate the balance between pro-apoptotic ceramides and mitogenic sphingosine-1-phosphate. The functions of the two SK isoenzymes, SK1 and SK2, are not redundant, with genetic ablation of SK2 having more pronounced anticancer effects than removal of SK1. Although several small molecule inhibitors of SKs have been described in the literature, detailed characterization of their molecular and cellular pharmacology, particularly their activities against human SK1 and SK2, have not been completed. Computational modeling of the putative active sites of SK1 and SK2 suggests structural differences that might allow isozyme-selective inhibitors. Therefore, we characterized several SK-inhibitory compounds which revealed differential inhibitory effects on SK1 and SK2 as follows: SKI-II and ABC294735 are SK1/2-dual inhibitors; CB5468139 is a SK1-selective inhibitor; and ABC294640 is a SK2-selective inhibitor. We examined the effects of the SK inhibitors on several biochemical and phenotypic processes in A498 kidney adenocarcinoma cells. The SK2-selective inhibitor ABC294640 demonstrated the most pronounced effects on SK1 and SK2 mRNA expression, decrease of S1P levels, elevation of ceramide levels, cell cycle arrest, and inhibition of proliferation, migration and invasion. ABC294640 also down-regulated the expression or activation of several signaling proteins, including STAT3, AKT, ERK, p21, p53 and FAK. These effects were equivalent or superior to responses to the SK1/2-dual inhibitors. Overall, these results suggest that inhibition of SK2 results in stronger anticancer effects than does inhibition of SK1 or both SK1 and SK2. PMID:22970244

Gao, Peng; Peterson, Yuri K; Smith, Ryan A; Smith, Charles D

2012-01-01

252

Characterization of Isoenzyme-Selective Inhibitors of Human Sphingosine Kinases  

PubMed Central

Sphingosine kinases (SKs) are promising new therapeutic targets for cancer because they regulate the balance between pro-apoptotic ceramides and mitogenic sphingosine-1-phosphate. The functions of the two SK isoenzymes, SK1 and SK2, are not redundant, with genetic ablation of SK2 having more pronounced anticancer effects than removal of SK1. Although several small molecule inhibitors of SKs have been described in the literature, detailed characterization of their molecular and cellular pharmacology, particularly their activities against human SK1 and SK2, have not been completed. Computational modeling of the putative active sites of SK1 and SK2 suggests structural differences that might allow isozyme-selective inhibitors. Therefore, we characterized several SK-inhibitory compounds which revealed differential inhibitory effects on SK1 and SK2 as follows: SKI-II and ABC294735 are SK1/2-dual inhibitors; CB5468139 is a SK1-selective inhibitor; and ABC294640 is a SK2-selective inhibitor. We examined the effects of the SK inhibitors on several biochemical and phenotypic processes in A498 kidney adenocarcinoma cells. The SK2-selective inhibitor ABC294640 demonstrated the most pronounced effects on SK1 and SK2 mRNA expression, decrease of S1P levels, elevation of ceramide levels, cell cycle arrest, and inhibition of proliferation, migration and invasion. ABC294640 also down-regulated the expression or activation of several signaling proteins, including STAT3, AKT, ERK, p21, p53 and FAK. These effects were equivalent or superior to responses to the SK1/2-dual inhibitors. Overall, these results suggest that inhibition of SK2 results in stronger anticancer effects than does inhibition of SK1 or both SK1 and SK2. PMID:22970244

Gao, Peng; Peterson, Yuri K.; Smith, Ryan A.; Smith, Charles D.

2012-01-01

253

Discovery of a Potent And Selective Aurora Kinase Inhibitor  

SciTech Connect

This communication describes the discovery of a novel series of Aurora kinase inhibitors. Key SAR and critical binding elements are discussed. Some of the more advanced analogues potently inhibit cellular proliferation and induce phenotypes consistent with Aurora kinase inhibition. In particular, compound 21 (SNS-314) is a potent and selective Aurora kinase inhibitor that exhibits significant activity in pre-clinical in vivo tumor models.

Oslob, J.D.; Romanowski, M.J.; Allen, D.A.; Baskaran, S.; Bui, M.; Elling, R.A.; Flanagan, W.M.; Fung, A.D.; Hanan, E.J.; Harris, S.; Heumann, S.A.; Hoch, U.; Jacobs, J.W.; Lam, J.; Lawrence, C.E.; McDowell, R.S.; Nannini, M.A.; Shen, W.; Silverman, J.A.; Sopko, M.M.; Tangonan, B.T.

2009-05-21

254

Defining the COX inhibitor selectivity of NSAIDs: implications for understanding toxicity.  

PubMed

The hypothesis that the anti-inflammatory activity of NSAIDs derives from COX inhibition is well established. It also underpins the accepted mechanism of the gastrointestinal and renal toxicity of NSAIDs. However, in terms of NSAID-induced cardiovascular toxicity, is COX inhibition then guilty by association? Multiple experimental models of COX-1/COX-2 inhibition have enabled ranking of the relative inhibitory activity of NSAIDs. Inhibition is expressed as an IC(50) value and the index of COX selectivity as the ratio of the IC(50) value for COX-2 and COX-1. These data informed the 'imbalance hypothesis' that the cardiovascular risk of NSAIDs results from an imbalance in the detrimental actions of COX-1-derived thromboxane A(2) and the beneficial actions of COX-2-derived prostacyclin (PGI(2)). Data derived from in vitro models used to generate NSAID IC(50) values are discussed in the context of the difficulties in defining COX selectivity and hence understanding the toxicity of NSAIDs in current clinical use. PMID:22111779

Knights, Kathleen M; Mangoni, Arduino A; Miners, John O

2010-11-01

255

Potency and selectivity of carprofen enantiomers for inhibition of bovine cyclooxygenase in whole blood assays.  

PubMed

Whole blood in vitro assays were used to determine the potency and selectivity of carprofen enantiomers for inhibition of the isoforms of cyclooxygenase (COX), COX-1 and COX-2, in the calf. S(+)-carprofen possessed preferential activity for COX-2 inhibition but, because the slopes of inhibition curves differed, the COX-1:COX-2 inhibition ratio decreased from 9.04:1 for inhibitory concentration (IC)10 to 1.84:1 for IC95. R(-) carprofen inhibited COX-2 preferentially only for low inhibition of the COX isoforms (IC10 COX-1:COX-2=6.63:1), whereas inhibition was preferential for COX-1 for a high level of inhibition (IC95 COX-1:COX-2=0.20:1). S(+) carprofen was the more potent inhibitor of COX isoforms; potency ratios S(+):R(-) carprofen were 11.6:1 for IC10 and 218:1 for IC90. Based on serum concentrations of carprofen enantiomers obtained after administration of a therapeutic dose of 1.4 mg/kg to calves subcutaneously, S(+)-carprofen concentrations exceeded the in vitro IC80 COX-2 value for 32 h and the IC20 for COX-1 for 33 h. The findings are discussed in relation to efficacy and safety of carprofen in calves. PMID:22703724

Brentnall, Claire; Cheng, Zhangrui; McKellar, Quintin A; Lees, Peter

2012-12-01

256

COX-2 expression predicts worse breast cancer prognosis and does not modify the association with aspirin  

PubMed Central

Background Some studies have found worse prognosis among COX-2 expressing breast cancers. Aspirin and NSAIDs inhibit COX-2. Three studies, including ours, have reported a survival advantage among women with breast cancer who take either aspirin or NSAIDs. We hypothesized that in the Nurses’ Health Study (NHS), COX-2 expression would be associated with worse prognosis, and aspirin use would be associated with better survival particularly among women with COX-2 positive tumors. Methods We studied 2,001 women with invasive breast cancers stained for COX-2 by immunohistochemistry. Tumor prognostic factors were from medical records. Aspirin use was assessed at least 12 months after diagnosis and updated. Cause of death was from death certificates. Statistical analyses included logistic regression of prognostic factors with COX-2 status as the outcome, and proportional hazards regression with breast cancer death as the outcome. Results Tumor COX-2 expression was associated with higher diagnostic stage. Compared with stage I, the RR(95% CI) for stages II-IV were 1.16(0.93–1.45), 1.68(1.27–2.22), and 1.76(0.93–3.32). COX-2 expression was associated with lobular compared with ductal histology, (1.40[1.02–1.92]), and estrogen receptor positive compared with negative (2.22[1.66–2.95]). The RR(95% CI) of breast cancer death for current aspirin use was similar for women with COX-2 positive and negative tumors; 0.64(0.43–0.96) and 0.57(0.44–0.74) respectively. Conclusions In the NHS, COX-2 breast cancer expression was associated with higher stage at diagnosis. The survival benefit associated with aspirin use did not differ by COX-2 status. Impact COX-2 breast cancer expression is associated with worse prognosis. If aspirin truly impacts breast cancer survival, it is not solely via COX-2. PMID:21728052

Holmes, Michelle D.; Chen, Wendy Y.; Schnitt, Stuart J.; Collins, Laura; Colditz, Graham A.; Hankinson, Susan E.; Tamimi, Rulla M.

2012-01-01

257

SAR156497, an Exquisitely Selective Inhibitor of Aurora Kinases.  

PubMed

The Aurora family of serine/threonine kinases is essential for mitosis. Their crucial role in cell cycle regulation and aberrant expression in a broad range of malignancies have been demonstrated and have prompted intensive search for small molecule Aurora inhibitors. Indeed, over 10 of them have reached the clinic as potential anticancer therapies. We report herein the discovery and optimization of a novel series of tricyclic molecules that has led to SAR156497, an exquisitely selective Aurora A, B, and C inhibitor with in vitro and in vivo efficacy. We also provide insights into its mode of binding to its target proteins, which could explain its selectivity. PMID:25369539

Carry, Jean-Christophe; Clerc, François; Minoux, Hervé; Schio, Laurent; Mauger, Jacques; Nair, Anil; Parmantier, Eric; Le Moigne, Ronan; Delorme, Cécile; Nicolas, Jean-Paul; Krick, Alain; Abécassis, Pierre-Yves; Crocq-Stuerga, Véronique; Pouzieux, Stéphanie; Delarbre, Laure; Maignan, Sébastien; Bertrand, Thomas; Bjergarde, Kirsten; Ma, Nina; Lachaud, Sylvette; Guizani, Houlfa; Lebel, Rémi; Doerflinger, Gilles; Monget, Sylvie; Perron, Sébastien; Gasse, Francis; Angouillant-Boniface, Odile; Filoche-Rommé, Bruno; Murer, Michel; Gontier, Sylvie; Prévost, Céline; Monteiro, Marie-Line; Combeau, Cécile

2015-01-01

258

The bitter barricading of prostaglandin biosynthesis pathway: understanding the molecular mechanism of selective cyclooxygenase-2 inhibition by amarogentin, a secoiridoid glycoside from Swertia chirayita.  

PubMed

Swertia chirayita, a medicinal herb inhabiting the challenging terrains and high altitudes of the Himalayas, is a rich source of essential phytochemical isolates. Amarogentin, a bitter secoiridoid glycoside from S. chirayita, shows varied activity in several patho-physiological conditions, predominantly in leishmaniasis and carcinogenesis. Experimental analysis has revealed that amarogentin downregulates the cyclooxygenase-2 (COX-2) activity and helps to curtail skin carcinogenesis in mouse models; however, there exists no account on selective inhibition of the inducible cyclooxygenase (COX) isoform by amarogentin. Hence the computer-aided drug discovery methods were used to unravel the COX-2 inhibitory mechanism of amarogentin and to check its selectivity for the inducible isoform over the constitutive one. The generated theoretical models of both isoforms were subjected to molecular docking analysis with amarogentin and twenty-one other Food and Drug Authority (FDA) approved lead molecules. The post-docking binding energy profile of amarogentin was comparable to the binding energy profiles of the FDA approved selective COX-2 inhibitors. Subsequent molecular dynamics simulation analysis delineated the difference in the stability of both complexes, with amarogentin-COX-2 complex being more stable after 40ns simulation. The total binding free energy calculated by MMGBSA for the amarogentin-COX-2 complex was -52.35 KCal/mol against a binding free energy of -8.57 KCal/mol for amarogentin-COX-1 complex, suggesting a possible selective inhibition of the COX-2 protein by the natural inhibitor. Amarogentin achieves this potential selectivity by small, yet significant, structural differences inherent to the binding cavities of the two isoforms. Hypothetically, it might block the entry of the natural substrates in the hydrophobic binding channel of the COX-2, inhibiting the cyclooxygenation step. To sum up briefly, this work highlights the mechanism of the possible selective COX-2 inhibition by amarogentin and endorses the possibility of obtaining efficient, futuristic and targeted therapeutic agents for relieving inflammation and malignancy from this phytochemical source. PMID:24603686

Shukla, Shantanu; Bafna, Khushboo; Sundar, Durai; Thorat, Sunil S

2014-01-01

259

A High-Fat Diet Activates Oncogenic Kras and COX2 to Induce Development of Pancreatic Ductal Adenocarcinoma in Mice  

PubMed Central

Background & Aims Obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC), but it is not clear how obesity contributes to pancreatic carcinogenesis. The oncogenic form of KRAS is expressed during early stages of PDAC development, and is detected in almost all of these tumors. However, there is evidence that mutant KRAS requires an additional stimulus to activate its full oncogenic activity, and that this stimulus involves the inflammatory response. We investigated whether the inflammation induced by a high-fat diet, and accompanying up-regulation of cyclooxygenase-2 (COX2), increases Kras activity during pancreatic carcinogenesis in mice. Methods We studied mice with acinar cell-specific expression of KrasG12D (LSL-Kras/Ela-CreERT mice) alone or crossed with COX2 conditional knockout mice (COXKO/LSL-Kras/Ela-CreERT). We also studied LSL-Kras/PDX1 -Cre mice. All mice were fed isocaloric diets with different amounts of fat, and a COX2 inhibitor was administered to some LSL-Kras/Ela-CreERT mice. Pancreata were collected from mice and analyzed for Kras activity, levels of phosphorylated ERK, inflammation, fibrosis, pancreatic intraepithelial neoplasia (PanIN), and PDACs. Results Pancreatic tissues from LSL-Kras/Ela-CreERT mice fed high-fat diets (HFDs) had increased Kras activity, fibrotic stroma, and numbers of PanINs and PDACs than LSL-Kras/Ela-CreERT mice fed control diets; the mice fed the HFDs also had shorter survival times than mice fed control diets. Administration of a COX2 inhibitor to LSL-Kras/Ela-CreERT mice prevented these effects of HFDs. We also observed a significant reduction in survival times of mice fed HFDs. COXKO/LSL-Kras/Ela-CreERT mice fed HFDs had no evidence for increased numbers of PanIN lesions, inflammation, or fibrosis, as opposed to the increases observed in LSL-Kras/Ela-CreERT mice fed HFDs. Conclusions In mice, a HFD can activate oncogenic Kras via COX2, leading to pancreatic inflammation and fibrosis, and development of PanINs and PDAC. This mechanism could be involved in the association between risk for PDAC and HFDs. PMID:23958541

Philip, Bincy; Roland, Christina L.; Daniluk, Jaroslaw; Liu, Yan; Chatterjee, Deyali; Gomez, Sobeyda B.; Ji, Baoan; Huang, Haojie; Wang, Huamin; Fleming, Jason B.; Logsdon, Craig D.; Cruz-Monserrate, Zobeida

2013-01-01

260

Antiproliferative effects of selective cyclooxygenase-2 inhibitor modulated by nimotuzumab in estrogen-dependent breast cancer cells.  

PubMed

Breast cancer is the most common malignancy in women, and many breast cancer patients fail conventional treatment strategies of chemotherapy, radiation, and antiestrogen therapy. Research into the molecular pathways and biomarkers involved in the development of breast cancer should yield information that will guide therapeutic decisions. Epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) are involved in the carcinogenesis of breast cancer and exist tight crosstalk with estrogen receptor (ER) pathway. Combination of EGFR and COX-2 inhibitors, therefore, could be an effective strategy for reducing cell growth in estrogen-dependent breast cancer. In order to verify the effects of EGFR and COX-2 inhibitors, breast cancer cells MCF-7 and SKBR-3 were characterized for receptors status and then treated with respective inhibitors (nimotuzumab and celecoxib) alone and in combination. Both cell lines were sensitive to celecoxib, but not to nimotuzumab. However, combination of two drugs demonstrated synergistic effects on cell killing. Moreover, association of two drugs resulted in SKBR-3 cells, a further G0/G1 phase arrest than one drug alone. Downregulation of p-EGFR, p-Akt, p-mTOR, and amplified in breast cancer 1 (AIB1) were observed in both cell lines, and upregulation of E-cadherin was only found in MCF-7, after treatment with single agent or in combination. These studies suggest that nimotuzumab and celecoxib exert synergistic antiproliferation effects in breast cancer, which partly correlates with ER status. Due to Akt/mTOR, EMT and AIB1 pathways participate in this process, therefore, E-cadherin and AIB1 may be considered as possible biomarkers to predict response in ER-positive breast cancer cells treated with EGFR and COX-2 inhibitors. PMID:22252523

Wang, Ying-Xue; Gao, Jin-Xiang; Wang, Xiu-Yun; Zhang, Li; Liu, Chang-Mei

2012-08-01

261

Anilino-monoindolylmaleimides as potent and selective JAK3 inhibitors.  

PubMed

We designed a series of anilino-indoylmaleimides based on structural elements from literature JAK3 inhibitors 3 and 4, and our lead 5. These new compounds were tested as inhibitors of JAKs 1, 2 and 3 and TYK2 for therapeutic intervention in rheumatoid arthritis (RA). Our requirements, based on current scientific rationale for optimum efficacy against RA with reduced side effects, was for potent, mixed JAK1 and 3 inhibition, and selectivity over JAK2. Our efforts yielded a potent JAK3 inhibitor 11d and its eutomer 11e. These compounds were highly selective for inhibition of JAK3 over JAK2 and TYK. The compounds displayed only modest JAK1 inhibition. PMID:24461299

McDonnell, Mark E; Bian, Haiyan; Wrobel, Jay; Smith, Garry R; Liang, Shuguang; Ma, Haiching; Reitz, Allen B

2014-02-15

262

Probiotics Regulate the Expression of COX2 in Intestinal Epithelial Cells  

Microsoft Academic Search

Cyclooxygenase-2 (COX) 2 promotes intestinal wound healing but elicits also proinflammatory effects and has been implicated in colorectal carcinogenesis. Thus, a balanced expression of COX-2 is essential for intestinal homeostasis. This study was designed to evaluate the regulation of COX-2 by probiotic organisms and to characterize ligands and receptors involved. Colo320 and SW480 intestinal epithelial cells (IEC) were stimulated with

Jan-Michel Otte; Rudja Mahjurian-Namari; Stephan Brand; Ilka Werner; Wolfgang E. Schmidt; Frank Schmitz

2008-01-01

263

Safety of Selective Serotonin Reuptake Inhibitors in Pregnancy  

Microsoft Academic Search

Psychiatric treatment with selective serotonin reuptake inhibitors (SSRIs) may be desirable or necessary during pregnancy; however, the benefit of these treatments must balance the benefits to the mother with any risk to the developing foetus. At the present time, the role of serotonin in normal central nervous system development, as well as the effects of altering serotonin transmission at critical

Carlos D. las Cuevas; Emilio J. Sanz

2006-01-01

264

Selective non zinc binding inhibitors of MMP13  

Microsoft Academic Search

Directed screening has identified a novel series of MMP13 inhibitors that possess good levels of activity whilst possessing excellent selectivity over related MMPs. The binding mode of the series has been solved by co-crystallisation and demonstrates an interesting mode of inhibition without interaction with the catalytic zinc atom.

Chris De Savi; Andrew D. Morley; Attilla Ting; Ian Nash; Kostas Karabelas; Christine M. Wood; Michael James; Stephen J. Norris; Galith Karoutchi; Neil Rankine; Gordon Hamlin; Philip A. MacFaul; David Ryan; Sarah V. Baker; David Hargreaves; Stefan Gerhardt

2011-01-01

265

Selective inhibitors of death in mutant huntingtin cells  

E-print Network

undergo cell death at a rate greater than that of the parental ST14A5. We developed a highSelective inhibitors of death in mutant huntingtin cells Hemant Varma1, Cindy Voisine2, C Todd De of cell death in mutant huntingtin­expressing cells. Four compounds were active in diverse HD models

Stockwell, Brent R.

266

Selective Serotonin Reuptake Inhibitor (SSRI) Drugs: More Risks Than Benefits?  

Microsoft Academic Search

Anecdotal reports have suggested that selective serotonin reuptake inhibitors (SSRIs) may cause suicidal or violent behavior in some patients. Because of the publicity surrounding certain events, and the numerous lawsuits that have been filed, a review of benefits and risks is needed. At most 30% of patients receive a benefit from SSRIs beyond the large placebo effect in certain mental

Joel M. Kauffman

2009-01-01

267

Selective Serotonin Reuptake Inhibitors and Intraoperative Blood Pressure  

Microsoft Academic Search

BackgroundThe influence of selective serotonin reuptake inhibitors (SSRIs) on blood pressure is poorly understood. We hypothesized that if SSRIs have an influence on blood pressure, this might become manifest in changes in intraoperative blood pressure. We aimed to study the association between perioperative use of SSRIs and changes in intraoperative blood pressure by measuring the occurrence of intraoperative hyper- and

Ingrid M. M. van Haelst; Wilton A. van Klei; Hieronymus J. Doodeman; Cor J. Kalkman; Toine C. G. Egberts

2012-01-01

268

Celecoxib: a potent cyclooxygenase-2 inhibitor in cancer prevention.  

PubMed

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most widely used therapeutic agents in the treatment of pain, inflammation and fever. They may also have a role in the management of cancer prevention, Alzheimer's disease and prophylaxis against cardiovascular disease. These drugs act primarily by inhibiting cyclooxygenase enzyme, which has two isoforms, cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). Selective COX-2 inhibitors provide potent anti-inflammatory and analgesic effects without the side effects of gastric and renal toxicity and inhibition of platelet function. Celecoxib is a potent COX-2 inhibitor being developed for the treatment of rheumatoid arthritis and osteoarthritis. Chemoprevention is the use of pharmacological or natural agents to prevent, suppress, interrupt or reverse the process of carcinogenesis. For this purpose, celecoxib is being used for different cancer types. The effects of NSAIDs on tumor growth remain unclear, but are most likely to be multifocal. In this article, we reviewed COX-2 selectivity, the pharmacological properties of celecoxib, the use of celecoxib for cancer prevention and the mechanisms of chemoprevention. PMID:15068837

Kismet, Kemal; Akay, M Turan; Abbasoglu, Osman; Ercan, Aygün

2004-01-01

269

5-methoxyindole metabolites of L-tryptophan: control of COX-2 expression, inflammation and tumorigenesis  

PubMed Central

Cyclooxygenase-2(COX-2) overexpression promotes inflammation and tumorigenesis. COX-2 expression in response to diverse stimuli is tightly controlled to avoid persistent overexpression. 5-methoxyindole metabolites of L-tryptophan represent a new class of compounds that control COX-2 expression at the transcriptional level. Two of the metabolites, the newly discovered 5-methoxytryptophan (5-MTP, also known as cytoguardin) and N-acetyl 5-methoxytryptamine (melatonin) are the focus of this review. 5-MTP is produced by mesenchymal cells such as fibroblasts via 5-hydroxytryptophan (5-HTP). It inhibits COX-2 transcriptional activation induced by diverse proinflammatory and mitogenic factors. Cancer cells are deficient in cytoguardin production which contributes to COX-2 overexpression. Fibroblast-generated 5-MTP is capable of restoring the control of COX-2 overexpression in cancer cells. 5-MTP blocks cancer cell migration and invasion in vitro and inhibits tumor growth and cancer metastasis in a xenograft model. Melatonin possesses similar COX-2 suppressing and anti-cancer properties albeit at supra-pharmacological concentrations. By contrast, 5-hydroxyindole metabolites of L-tryptophan such as 5-hydroxytryptamine (serotonin), 5-hydroxytryptophol and other serotonin catabolites do not control COX-2 expression. 5-hydroxytryptophan inhibits COX-2 expression through conversion to 5-MTP. The physiological relevance of 5-MTP as an endogenous regulator of inflammation and cancer metastasis remains to be investigated. On the other hand, 5-methoxyindole metabolites of tryptophan are valuable lead compounds for development of new anti-inflammatory drugs and cancer chemoprevention. PMID:24589238

2014-01-01

270

Chapter 2: Mechanistic Aspects of COX-2 Expression in Colorectal Neoplasia  

PubMed Central

The cyclooxygenase-2 (COX-2) enzyme catalyzes the rate-limiting step of prostaglandin formation in pathogenic states and a large amount of evidence has demonstrated constitutive COX-2 expression to be a contributing factor promoting colorectal cancer (CRC). Various genetic, epigenetic, and inflammatory pathways have been identified to be involved in the etiology and development of CRC. Alteration in these pathways can influence COX-2 expression at multiple stages of colon carcinogenesis allowing for elevated prostanoid biosynthesis to occur in the tumor microenvironment. In normal cells, COX-2 expression levels are potently regulated at the post-transcriptional level through various RNA sequence elements present within the mRNA 3?-untranslated region(3?UTR). A conserved AU-rich element(ARE) functions to target COX-2 mRNA for rapid decay and translational inhibition through association with various RNA-binding proteins to influence the fate of COX-2 mRNA. Specific microRNAs bind regions within the COX-2 3?UTR and control COX-2 expression. In this chapter, we discuss novel insights in the mechanisms of altered posttranscriptional regulation of COX-2 in CRC and how this knowledge may be used to develop novel strategies for cancer prevention and treatment. PMID:22893198

Dixon, Dan A.; Blanco, Fernando F.; Bruno, Annalisa; Patrignani, Paola

2012-01-01

271

Motion--Cyclo-oxygenase-2 selective nonsteroidal anti-inflammatory drugs are as safe as placebo for the stomach: arguments against the motion.  

PubMed

Cyclo-oxygenase (COX) exists in two isoforms, COX-1 and COX-2, that direct the synthesis of prostaglandins, prostacyclin and thromboxane. Traditional nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both isoenzymes, resulting in damage to the mucosa of the stomach and duodenum, but also in cardioprotection. Selective COX-2 inhibitors are less likely to damage the upper gastrointestinal tract, as has been shown by large, randomized, controlled trials. Specifically, the newer agents are superior to ibuprofen and naproxen in this regard, but celecoxib and diclofenac were not significantly different in patients who were not also taking low-dose acetylsalicylic acid. These studies did not include a placebo arm, however, and controlled comparisons of COX-2 inhibitors with placebo have not enlisted enough subjects to demonstrate conclusively that they are equally safe. Selectivity for the COX-2 isoform affords protection against upper gastrointestinal toxicity possibly at the expense of the cardioprotective effect of traditional NSAIDs. This might explain the higher rate of nonfatal myocardial infarction in patients who are given rofecoxib compared with naproxen. A traditional NSAID, combined with either misoprostol or a proton pump inhibitor, is still a suitable alternative to selective COX-2 inhibitors for the treatment of arthritis. PMID:12772009

Maetzel, Andreas

2003-05-01

272

Surface plasmon resonance studies and biochemical evaluation of a potent peptide inhibitor against cyclooxygenase-2 as an anti-inflammatory agent.  

PubMed

Cyclooxygenase (COX) is a key enzyme in the biosynthetic pathway leading to the formation of prostaglandins, which are mediators of inflammation [D.L. Dewitt, W.L. Smith, Primary structure of prostaglandin G/H synthase from sheep vesicular gland determined from the complementary DNA sequence, Proc. Natl. Acad. Sci. USA 85 (1988) 1412-1416, 1]. It exists mainly in two isoforms COX-1 and COX-2 [A. Raz, A. Wyche, N. Siegel, P. Needleman, Regulation of fibroblast cyclooxygenase synthesis by interleukin-1, J. Biol. Chem. 263 (1988) 3022-3028, 2]. The conventional non-steroidal anti-inflammatory drugs (NSAIDs) have adverse gastrointestinal side-effects, because they inhibit both isoforms [T.D. Warner, F. Guiliano, I. Vojnovic, A. Bukasa, J.A. Mitchell, J.P. Vane, Nonsteroid drug selectivities for cyclo-oxygenase-1 rather than cyclo-oxygenase-2 are associated with human gastrointestinal toxicity: a full in vitro analysis, Proc. Natl. Acad. Sci. USA 96 (1999) 7563-7568, 3; L.J. Marnett, A.S. Kalgutkar, Cyclooxygenase 2 inhibitors: discovery, selectivity and the future, Trends Pharmacol. Sci. 20 (1999) 465-469, 4; J.R. Vane, NSAIDs, Cox-2 inhibitors, and the gut, Lancet 346 (1995) 1105-1106, 5]. Therefore drugs which selectively inhibit COX-2, known as coxibs were developed. Recent reports on the harmful cardiovascular and renovascular side-effects of the anti-inflammatory drugs have led to the quest for a novel class of COX-2 selective inhibitors. Keeping this in mind, we have used the X-ray crystal structures of the complexes of the COX-1 and COX-2 with the known inhibitors for a rational, structure based approach to design a small peptide, which is potent inhibitor for COX-2. The peptides have been checked experimentally by in-vitro kinetic studies using surface plasmon resonance (SPR) and other biochemical methods. We have identified a tripeptide inhibitor which is a potential lead for a new class of COX-2 inhibitor. The dissociation constant (K(D)) determined for COX-2 with peptide WCS is 1.90x10(-10)M, the kinetic constant (K(i)) determined by spectrophotometry is 4.85x10(-9)M and the IC(50) value is 1.5x10(-8)M by ELISA test. PMID:17640617

Somvanshi, Rishi K; Kumar, Ashwini; Kant, Shashi; Gupta, Deepti; Singh, S Bhaskar; Das, Utpal; Srinivasan, Alagiri; Singh, Tej P; Dey, Sharmistha

2007-09-14

273

The aromatic volatile organic compounds toluene, benzene and styrene induce COX-2 and prostaglandins in human lung epithelial cells via oxidative stress and p38 MAPK activation.  

PubMed

Toluene, benzene and styrene are volatile organic compounds (VOCs) widely distributed in the environment. Tobacco smoke, traffic exposure and solvents used for paints, rubber and adhesives are known sources for these compounds. The aim of the present study was to investigate whether toluene, benzene and styrene can induce inflammatory reactions in lung cells and to characterize possible underlying mechanisms. A previous study gave evidence that expression of cyclooxygenase-2 (COX-2) is upregulated following exposure to the aromatic VOC chlorobenzene. Here, we investigated the effects of the aromatics toluene, benzene and styrene on human lung cells, with emphasis on COX-2, the rate-limiting enzyme of the prostaglandin pathway. In addition, we studied the potential role of oxidative stress and p38 MAPK activation in the toluene/benzene/styrene-dependent COX-2 induction. Following exposure to the aromatic compounds the expression level of COX-2 increased markedly. In addition, prostaglandin E(2) (PGE(2)) and prostaglandin F(2?) (PGF(2?)), major products of the COX enzyme, were found to be upregulated in response to toluene, benzene or styrene exposure. Furthermore, we observed an activation of p38 MAPK resulting from aromatic VOC exposure. Treatment of the cells with a specific p38 inhibitor (SB203580) or the antioxidant N-acetylcysteine (NAC) was able to prevent the toluene/benzene/styrene-dependent COX-2 activation, and subsequent increased PGE(2) and PGF(2?) secretion. These results suggest that toluene, benzene and styrene induce production and secretion of PGE(2) and PGF(2?) in lung epithelial cells via p38 MAPK and COX-2 activation in a redox sensitive manner. PMID:21801798

Mögel, Iljana; Baumann, Sven; Böhme, Alexander; Kohajda, Tibor; von Bergen, Martin; Simon, Jan-Christoph; Lehmann, Irina

2011-10-28

274

Cyclooxygenase-1 vs. cyclooxygenase-2 inhibitors in the induction of antinociception in rodent withdrawal reflexes.  

PubMed

Non-steroidal antiinflammatory drugs (NSAIDs) inhibit the cyclooxygenase (COX) enzyme and so they are effective analgesic, antiinflammatory and antipyretic drugs. The discovery of COX-2 led to the search for new NSAIDs with a selective action over this isoenzyme. The experiments performed to date have shown either more, less or no different efficacy of new COX-2 selective NSAIDs when compared to the non-selective inhibitors, probably because the comparison has not been performed under similar conditions. We have therefore compared the analgesic activity of six NSAIDs with different selectivity for the COX isoenzymes. The experiments were performed using the recording of spinal cord nociceptive reflexes in anaesthetised rats and in awake mice. The non-selective COX inhibitors, such as dexketoprofen trometamol, were effective in reducing nociceptive responses both in normal and monoarthritic rats (ED50s: 0.31 and 3.97 micromol/kg, respectively), and in mice with paw inflammation (12.5 micromol/kg, p < 0.01). The COX-1 selective inhibitor SC-58560 showed efficacy in normal rats (ED50: 0.8 micromol/kg) and in mice with paw inflammation (15 micromol/kg, p < 0.05), but not in monoarthritic rats. The COX-2 selective inhibitors celecoxib (105 micromol/kg) and rofecoxib (128 micromol/kg) however, were not effective in any of the groups studied. We conclude that inhibition of both COX isoenzymes is needed to achieve an effective analgesia in inflammation. PMID:11378164

Mazario, J; Gaitan, G; Herrero, J F

2001-06-01

275

Reversible Suppression of Cyclooxygenase 2 (COX-2) Expression In Vivo by Inducible RNA Interference  

PubMed Central

Prostaglandin-endoperoxide synthase 2 (PTGS2), also known as cyclooxygenase 2 (COX-2), plays a critical role in many normal physiological functions and modulates a variety of pathological conditions. The ability to turn endogenous COX-2 on and off in a reversible fashion, at specific times and in specific cell types, would be a powerful tool in determining its role in many contexts. To achieve this goal, we took advantage of a recently developed RNA interference system in mice. An shRNA targeting the Cox2 mRNA 3?untranslated region was inserted into a microRNA expression cassette, under the control of a tetracycline response element (TRE) promoter. Transgenic mice containing the COX-2-shRNA were crossed with mice encoding a CAG promoter-driven reverse tetracycline transactivator, which activates the TRE promoter in the presence of tetracycline/doxycycline. To facilitate testing the system, we generated a knockin reporter mouse in which the firefly luciferase gene replaces the Cox2 coding region. Cox2 promoter activation in cultured cells from triple transgenic mice containing the luciferase allele, the shRNA and the transactivator transgene resulted in robust luciferase and COX-2 expression that was reversibly down-regulated by doxycycline administration. In vivo, using a skin inflammation-model, both luciferase and COX-2 expression were inhibited over 80% in mice that received doxycycline in their diet, leading to a significant reduction of infiltrating leukocytes. In summary, using inducible RNA interference to target COX-2 expression, we demonstrate potent, reversible Cox2 gene silencing in vivo. This system should provide a valuable tool to analyze cell type-specific roles for COX-2. PMID:24988319

Zaiss, Anne K.; Zuber, Johannes; Chu, Chun; Machado, Hidevaldo B.; Jiao, Jing; Catapang, Arthur B.; Ishikawa, Tomo-o; Gil, Jose S.; Lowe, Scott W.; Herschman, Harvey R.

2014-01-01

276

miR-143 decreases COX-2 mRNA stability and expression in pancreatic cancer cells.  

PubMed

Small non-coding RNAs, microRNAs (miRNA), inhibit the translation or accelerate the degradation of message RNA (mRNA) by targeting the 3'-untranslated region (3'-UTR) in regulating growth and survival through gene suppression. Deregulated miRNA expression contributes to disease progression in several cancers types, including pancreatic cancers (PaCa). PaCa tissues and cells exhibit decreased miRNA, elevated cyclooxygenase (COX)-2 and increased prostaglandin E2 (PGE2) resulting in increased cancer growth and metastases. Human PaCa cell lines were used to demonstrate that restoration of miRNA-143 (miR-143) regulates COX-2 and inhibits cell proliferation. miR-143 were detected at fold levels of 0.41 ± 0.06 in AsPC-1, 0.20 ± 0.05 in Capan-2 and 0.10 ± 0.02 in MIA PaCa-2. miR-143 was not detected in BxPC-3, HPAF-II and Panc-1 which correlated with elevated mitogen-activated kinase (MAPK) and MAPK kinase (MEK) activation. Treatment with 10 ?M of MEK inhibitor U0126 or PD98059 increased miR-143, respectively, by 187 ± 18 and 152 ± 26-fold in BxPC-3 and 182 ± 7 and 136 ± 9-fold in HPAF-II. miR-143 transfection diminished COX-2 mRNA stability at 60 min by 2.6 ± 0.3-fold in BxPC-3 and 2.5 ± 0.2-fold in HPAF-II. COX-2 expression and cellular proliferation in BxPC-3 and HPAF-II inversely correlated with increasing miR-143. PGE2 levels decreased by 39.3 ± 5.0% in BxPC-3 and 48.0 ± 3.0% in HPAF-II transfected with miR-143. Restoration of miR-143 in PaCa cells suppressed of COX-2, PGE2, cellular proliferation and MEK/MAPK activation, implicating this pathway in regulating miR-143 expression. PMID:23973710

Pham, Hung; Rodriguez, C Ekaterina; Donald, Graham W; Hertzer, Kathleen M; Jung, Xiaoman S; Chang, Hui-Hua; Moro, Aune; Reber, Howard A; Hines, O Joe; Eibl, Guido

2013-09-13

277

Synthesis and in vivo evaluation of [18F]-4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide as a PET imaging probe for COX-2 expression.  

PubMed

Synthesis of [18F]4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide ([18F]celecoxib), a selective COX-2 inhibitor, is achieved via a bromide to [18F]F- exchange reaction. Synthesis of the precursor for radiolabeling was achieved from 4'-methylacetophenone in four steps with 22% overall yield. Under non-radioactive conditions, fluorination was achieved using TBAF in DMSO at 135 degrees C in 80% yield. Synthesis of [18F]celecoxib was achieved using [18F]TBAF in DMSO at 135 degrees C in 10+/-2% yield (EOS) with >99% chemical and radiochemical purities. The specific activity was 120+/-40 mCi/micromol (EOB). [18F]celecoxib was found to be stable in ethanol, however, de[18F]fluorination (6.5%) was observed after 4 h in 10% ethanol-saline solution. Rodent PET studies show bone labeling indicating in vivo de[18F]fluorination of [18F]celecoxib. PET studies in baboon indicated a lower rate of de[18F]fluorination than rat and retention of radioactivity in brain regions consistent with the known distribution of COX-2. A radiolabeling method that can generate consistent high specific activity is needed for routine human use. PMID:17166726

Prabhakaran, Jaya; Underwood, Mark D; Parsey, Ramin V; Arango, Victoria; Majo, Vattoly J; Simpson, Norman R; Van Heertum, Ronald; Mann, J John; Kumar, J S Dileep

2007-02-15

278

Polyoxometalates-Potent and selective ecto-nucleotidase inhibitors.  

PubMed

Polyoxometalates (POMs) are inorganic cluster metal complexes that possess versatile biological activities, including antibacterial, anticancer, antidiabetic, and antiviral effects. Their mechanisms of action at the molecular level are largely unknown. However, it has been suggested that the inhibition of several enzyme families (e.g., phosphatases, protein kinases or ecto-nucleotidases) by POMs may contribute to their pharmacological properties. Ecto-nucleotidases are cell membrane-bound or secreted glycoproteins involved in the hydrolysis of extracellular nucleotides thereby regulating purinergic (and pyrimidinergic) signaling. They comprise four distinct families: ecto-nucleoside triphosphate diphosphohydrolases (NTPDases), ecto-nucleotide pyrophosphatases/phosphodiesterases (NPPs), alkaline phosphatases (APs) and ecto-5'-nucleotidase (eN). In the present study, we evaluated the inhibitory potency of a series of polyoxometalates as well as chalcogenide hexarhenium cluster complexes at a broad range of ecto-nucleotidases. [Co4(H2O)2(PW9O34)2](10-) (5, PSB-POM142) was discovered to be the most potent inhibitor of human NTPDase1 described so far (Ki: 3.88nM). Other investigated POMs selectively inhibited human NPP1, [TiW11CoO40](8-) (4, PSB-POM141, Ki: 1.46nM) and [NaSb9W21O86](18-) (6, PSB-POM143, Ki: 4.98nM) representing the most potent and selective human NPP1 inhibitors described to date. [NaP5W30O110](14-) (8, PSB-POM144) strongly inhibited NTPDase1-3 and NPP1 and may therefore be used as a pan-inhibitor to block ATP hydrolysis. The polyoxoanionic compounds displayed a non-competitive mechanism of inhibition of NPPs and eN, but appeared to be competitive inhibitors of TNAP. Future in vivo studies with selected inhibitors identified in the current study are warranted. PMID:25449596

Lee, Sang-Yong; Fiene, Amelie; Li, Wenjin; Hanck, Theodor; Brylev, Konstantin A; Fedorov, Vladimir E; Lecka, Joanna; Haider, Ali; Pietzsch, Hans-Jürgen; Zimmermann, Herbert; Sévigny, Jean; Kortz, Ulrich; Stephan, Holger; Müller, Christa E

2014-11-13

279

Discovery of Selective Menaquinone Biosynthesis Inhibitors against Mycobacterium tuberculosis  

PubMed Central

Aurachin RE (1) is a strong antibiotic that was recently found to possess MenA (1,4-dihydroxy-2-naphthoate prenyltransferase) and bacterial electron transport inhibitory activities. Aurachin RE is the only molecule in a series of aurachin natural products that has the chiral center in the alkyl side chain at C9?-position. To identify selective MenA inhibitors against Mycobacterium tuberculosis, a series of chiral molecules were designed based on the structures of previously identified MenA inhibitors and 1. The synthesized molecules were evaluated in in vitro assays including MenA enzyme and bacterial growth inhibitory assays. We could identify novel MenA inhibitors that showed significant increase in potency of killing non-replicating M. tuberculosis in the low oxygen recovery assay (LORA) without inhibiting other Gram-positive bacterial growth even at high concentrations. The MenA inhibitors reported here are useful new pharmacophores for the development of selective antimycobacterial agents with strong activity against non-replicating M. tuberculosis. PMID:22449052

Debnath, Joy; Siricilla, Shajila; Wan, Bajoie; Crick, Dean C.; Lenaerts, Anne J.; Franzblau, Scott G.; Kurosu, Michio

2012-01-01

280

Dietary Zinc Modulation of COX2 Expression and Lingual and Esophageal Carcinogenesis in Rats  

Microsoft Academic Search

Background: Cancer of the upper aerodigestive tract, includ- ing esophageal and tongue carcinomas, is a major cause of cancer deaths worldwide. Esophageal and tongue cancers have both been associated with dietary zinc deficiency (ZD), and cyclooxygenase (COX-2) is often overexpressed in these cancers. Using rat models, we examined whether zinc regu- lates COX-2 expression in these cancers. Method: Expression of

Louise Y. Y. Fong; Liang Zhang; Yubao Jiang; John L. Farber

2005-01-01

281

Peripheral administration of morphine attenuates postincisional pain by regulating macrophage polarization through COX-2-dependent pathway  

PubMed Central

Background Macrophage infiltration to inflammatory sites promotes wound repair and may be involved in pain hypersensitivity after surgical incision. We recently reported that the development of hyperalgesia during chronic inflammation is regulated by macrophage polarity, often referred to as proinflammatory (M1) or anti-inflammatory (M2) macrophages. Although opioids such as morphine are known to alter the inflammatory milieu of incisional wounds through interactions with immunocytes, the macrophage-mediated effects of morphine on the development of postincisional pain have not been well investigated. In this study, we examined how morphine alters pain hypersensitivity through phenotypic shifts in local macrophages during the course of incision-induced inflammation. Results Local administration of morphine in the early phase, but not in the late phase alleviated mechanical hyperalgesia, and this effect was reversed by clodronate-induced peripheral depletion of local macrophages. At the morphine-injected incisional sites, the number of pro-inflammatory F4/80+iNOS+M1 macrophages was decreased during the course of pain development whereas increased infiltration of wound healing F4/80+CD206+M2 macrophages was observed during the early phase. Morphine increased the gene expression of endogenous opioid, proenkephalin, and decreased the pronociceptive cytokine, interleukin-1?. Heme oxygenase (HO)-1 promotes the differentiation of macrophages to the M2 phenotype. An inhibitor of HO-1, tin protoporphyrin reversed morphine-induced analgesic effects and the changes in macrophage phenotype. However, local expression levels of HO-1 were not altered by morphine. Conversely, cyclooxygenase (COX)-2, primarily produced from peripheral macrophages in acute inflammation states, was up-regulated in the early phase at morphine-injected sites. In addition, the analgesic effects and a phenotype switching of infiltrated macrophages by morphine was reversed by local administration of a COX inhibitor, indomethacin. Conclusions Local administration of morphine alleviated the development of postincisional pain, possibly by altering macrophage polarity at the incisional sites. A morphine-induced shift in macrophage phenotype may be mediated by a COX-2-dependent mechanism. Therefore, ?-opioid receptor signaling in macrophages may be a potential therapeutic target during the early phase of postincisional pain development. PMID:24928142

2014-01-01

282

Effects of selective cyclooxygenase-2 and non-selective COX inhibition on myocardial function and perfusion  

PubMed Central

Non-selective NSAIDs and selective cyclooxygenase-2 (COX-2) inhibitors are purported to increase adverse cardiovascular events. We hypothesized COX-2 inhibitors would alter myocardial blood flow, microvascular reactivity, oxidative stress, and prostaglandin levels. Adult Yorkshire swine were divided into three groups: no drug (control, n=7), a non-selective COX inhibitor (naproxen 400mg daily, NAP, n=7), or a selective COX-2 inhibitor (celecoxib 200mg daily, CBX, n=7). After 7 weeks physiologic measurements were taken and tissue harvested. Animals in the CBX group demonstrated significantly higher blood pressure and rate pressure product. The NAP and CBX groups demonstrated an increased microvascular contraction response to serotonin. The NAP group showed increased myocardial levels of thromboxane and lower levels of prostacyclin. Levels of protein oxidative stress were increased in the CBX group. Myocardial apoptosis was lowest in the NAP group. Immunoblotting demonstrated decreased VEGF and phospho-eNOS expression in the NAP and CBX groups. Myocardial TNF? was increased in both the NAP and CBX groups. Immunostaining for thromboxane A2 synthase and receptor demonstrated expression within the vascular smooth muscle and no observable differences between groups. Non-selective and selective COX inhibition does not alter myocardial perfusion, but results in altered myocardial and vascular physiology that may have implications regarding cardiovascular risk. PMID:21233641

Robich, Michael P.; Chu, Louis M.; Burgess, Thomas A.; Feng, Jun; Bianchi, Cesario; Sellke, Frank W.

2011-01-01

283

Synthesis of thio-heterocyclic analogues from Baylis-Hillman bromides as potent cyclooxygenase-2 inhibitors.  

PubMed

A series of thio-substituted pyrimidine, benzoxazole, benzothiazole and triazole analogues were synthesized from Baylis-Hillman bromides in a clean and efficient way. The synthesized twenty new compounds were subjected to in vitro COX-1 and COX-2 inhibitory activity. Majority of compounds found to be highly selective COX-2 inhibitor. Seven compounds (16e, 16f, 16k, 16l, 16m, 16r and 16s) displayed anti-inflammatory activity at micromolar concentrations with IC50 values for COX-2 inhibition ranging from 2.93 to 5.34 ?M compared to reference drug whose IC50 is 2.66 ?M. All these seven compounds had very little COX-1 inhibition property and thus are suitable candidates for anti-inflammatory drugs with less gastrointestinal side effect. PMID:24661847

Santhoshi, Amlipur; Mahendar, Budde; Mattapally, Saidulu; Sadhu, Partha Sarathi; Banerjee, Sanjay Kumar; Jayathirtha Rao, Vaidya

2014-04-15

284

Pyridine analogues of nimesulide: design, synthesis, and in vitro and in vivo pharmacological evaluation as promising cyclooxygenase 1 and 2 inhibitors.  

PubMed

Nonsteroidal anti-inflammatory drugs (NSAIDs) represent one of the most prescribed medications, although the chronic use of such pharmacological agents is commonly associated with numerous side effects. The demonstration that the use of COX-2 selective or preferential inhibitors is associated with a better tolerability opened new horizons in the search of safer drugs for the management of inflammation. In the present study, we report the synthesis and the pharmacological evaluation of pyridine analogues of nimesulide, a COX-2 preferential inhibitor. The cyclooxygenases (COXs) inhibitory activities were evaluated in vitro using a human whole blood model. According to the in vitro results, a selection of compounds exhibiting moderate to high COX-2/COX-1 selectivity ratio (from weak COX-2 preferential inhibitors to compounds displaying a celecoxib-like selectivity profile) were further evaluated in vivo in a model of lambda carrageenan-induced pleurisy in rats. Some of the selected compounds displayed similar or improved anti-inflammatory properties when compared to nimesulide and celecoxib. PMID:19791801

Renard, Jean-François; Arslan, Deniz; Garbacki, Nancy; Pirotte, Bernard; de Leval, Xavier

2009-10-01

285

Measurement of cyclooxygenase isozyme inhibition in humans: exploring the clinical relevance of biochemical selectivity.  

PubMed

Treatment with highly selective cyclooxygenase-2 inhibitors is associated with significantly fewer serious adverse gastrointestinal events than is treatment with non-selective NSAIDs, provided that the drug employed inhibits COX-2 but not COX-1 at therapeutic plasma levels. Several factors might influence the gastrointestinal (GI) safety of a COX-2 inhibitor administered to an individual patient. These factors include pharmacokinetic and pharmacodynamic variables (e.g. COX-2 selectivity), the interaction of these features with preexisting risk factors for drug-dependent adverse effects, as well as the variability in the individual response. Biochemical selectivity is one of the determinants of the risk of experiencing a serious GI complication during long-term NSAID therapy. The wider the separation between the COX-2 and COX-1 dose-response curves of the inhibitor (an index of biochemical selectivity), the lower the probability of experiencing a clinically relevant inhibition of platelet COX-1 due to an unusually high drug level or intense pharmacodynamic response to a normal drug level. The clinical relevance of biochemical selectivity has to be studied in large GI outcome trials with adequate statistical power to detect realistic differences in these relatively rare events. PMID:11695252

Patrono, C

2001-01-01

286

15-deoxy-delta 12,14-prostaglandin J(2) inhibits the synthesis of the acute phase protein SIP24 in cartilage: Involvement of COX-2 in resolution of inflammation.  

PubMed

We previously demonstrated that, in the MC615 cartilage cell line, the p38/NF-kB pathway is activated both during differentiation and in response to an inflammatory stimulus. In both cases, the p38/NF-kB pathway activation leads to the expression of the lipocalin SIP24 and of COX-2. Given the fact that, in the same cells, the COX-2 expression is sustained during the inflammation resolution, at the same time that the SIP24 expression is suppressed, in the present study we tested the hypothesis that COX-2 products play a role in SIP24 repression. Taken together, our results suggest that, during the resolution of inflammation, COX-2 represses the acute phase protein SIP24 and restores physiological conditions, possibly through a pathway involving PPARgamma. Experimental evidences being the following: (1) 15-deoxy-delta 12,14-prostaglandin J(2), but not PGE(2): (i) inhibits the expression of SIP24 in the inflammatory phase and induces COX-2 synthesis; (ii) represses NF-kB activation induced by LPS; (iii) represses the synthesis of microsomal PGE Synthase-1 induced by LPS. (2) PPARgamma and PPARalpha are present in MC615 cells in both proliferating and hyperconfluent cultures. (3) PPARgamma ligand GW7845, but not PPARalpha ligand GW7647: (i) represses the expression of SIP24 induced by LPS; (ii) induces COX-2 expression. (4) p38 is involved in the PPARgamma mediated induction of COX-2. In fact 15-deoxy-delta 12,14-prostaglandin J(2) activates p38 and the cell pretreatment with the p38 specific inhibitor SB203580 represses the expression of COX-2 induced by both the 15-deoxy-delta12,14-prostaglandin J(2) and the PPARgamma ligand GW7845. PMID:18615580

Ulivi, Valentina; Cancedda, Ranieri; Cancedda, Fiorella Descalzi

2008-11-01

287

Cl(-)-selective microelectrodes: sensitivity to anionic Cl- transport inhibitors.  

PubMed

Cl(-)-selective microelectrodes, containing Corning code 477315 or 477913 liquid ion exchangers, are often used to measure extra- and intracellular Cl- activities in the presence of Cl- transport inhibitors such as furosemide, bumetanide, and the stilbene sulfonic acid derivative 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS). Because these inhibitors are anions in the physiological pH range and have relatively high lipid solubilities, they would be expected to interfere with the response to Cl- of these microelectrodes. Preliminary reports have confirmed this expectation. We examined the effect of furosemide, bumetanide, and SITS on the Cl(-)-selective barrels of double-barreled microelectrodes containing Corning code 477315 liquid anion exchanger and suitable for impaling small cells (e.g., epithelial cells). The results showed that at pH 8.2 in pure solutions of furosemide and bumetanide, these microelectrodes gave linear responses to the logarithm of furosemide or bumetanide concentrations ranging from 1 X 10(-2) to 1 X 10(-4) M. In the physiological pH range both these inhibitors (in concentrations of 0.1 mM) interfered significantly with the response of the microelectrodes to Cl- (in concentrations ranging from 100 to 1 mM). Calculated electrode sensitivities, relative to Cl-, were approximately 150 for both these compounds. Microelectrodes of this type appeared to be approximately 1,000 times as sensitive toward SITS as they were toward Cl-. PMID:3618768

Chao, A C; Armstrong, W M

1987-08-01

288

Arachidonate 12-lipoxygenases with reference to their selective inhibitors  

SciTech Connect

Lipoxygenase is a dioxygenase recognizing a 1-cis,4-cis-pentadiene of polyunsaturated fatty acids. The enzyme oxygenates various carbon atoms of arachidonic acid as a substrate and produces 5-, 8-, 12- or 15-hydroperoxy eicosatetraenoic acid with a conjugated diene chromophore. The enzyme is referred to as 5-, 8-, 12- or 15-lipoxygenase, respectively. Earlier we found two isoforms of 12-lipoxygenase, leukocyte- and platelet-type enzymes, which were distinguished by substrate specificity, catalytic activity, primary structure, gene intron size, and antigenicity. Recently, the epidermis-type enzyme was found as the third isoform. Attempts have been made to find isozyme-specific inhibitors of 12-lipoxygenase, and earlier we found hinokitol, a tropolone, as a potent inhibitor selective for the platelet-type 12-lipoxygenase. More recently, we tested various catechins of tea leaves and found that (-)-geotechnical gallate was a potent and selective inhibitor of human platelet 12-lipoxygenase with an IC{sub 5} of 0.14 {mu}M. The compound was much less active with 12-lipoxygenase of leukocyte-type, 15-, 8-, and 5-lipoxygenases, and cyclo oxygenases-1 and -2.

Yamamoto, Shozo [Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501 (Japan)]. E-mail: yamamosh@kyoto-wu.ac.jp; Katsukawa, Michiko [Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501 (Japan); Nakano, Ayumi [Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501 (Japan); Hiraki, Emi [Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501 (Japan); Nishimura, Kohji [Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504 (Japan); Jisaka, Mitsuo [Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504 (Japan); Yokota, Kazushige [Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504 (Japan); Ueda, Natsuo [Department of Biochemistry, School of Medicine, Kagawa University, Miki-cho, Kita-gun, Kagawa 761-0793 (Japan)

2005-12-09

289

Melittin suppresses VEGF-A-induced tumor growth by blocking VEGFR-2 and the COX-2-mediated MAPK signaling pathway.  

PubMed

Melittin (1) is a major polypeptide in honey bee venom that has been used traditionally against chronic inflammation and cancer. However, its molecular mechanism has not been determined. In this study, the antitumor effect of 1 was compared with that of NS398, a cyclooxygenase-2 (COX-2) inhibitor, in vivo and in vitro. Subcutaneous injection of 1 at 0.5 and 5 mg/kg suppressed significantly vascular endothelial growth factor (VEGF)-A-transfected highly metastatic Lewis lung cancer (VEGF-A-hm LLC) tumor growth by 25% and 57%, respectively. Also, 1 inhibited significantly the number of vessels around VEGF-A-hm LLC cells. The results were superior to those obtained in the mice treated with NS398. Compound 1 dose-dependently inhibited proliferation and tube formation in human umbilical vein endothelial cells (VEGF-A-HUVECs), without affecting cell viability in native HUVECs. In addition, 1 decreased the expression of VEGF receptor-2 (VEGFR-2), COX-2, and prostaglandin E2 (PGE2) in VEGF-A-transfected HUVECs. These effects were accompanied by a reduction of the phosphorylation of extracellular signal-regulated kinase 1/2 and c-jun N-terminal kinase, whereas it increased the phosphorylation of p38 mitogen-activated protein kinase (MAPK). SB203580 abolished the downregulation of COX-2 and VEGFR-2 and the inhibition of cell proliferation by 1. The antitumor activity of 1 may be associated with antiangiogenic actions via inhibiting VEGFR-2 and inflammatory mediators involved in the MAPK signaling pathway. PMID:23110475

Huh, Jeong-Eun; Kang, Jung Won; Nam, Dongwoo; Baek, Yong-Hyeon; Choi, Do-Young; Park, Dong-Suk; Lee, Jae-Dong

2012-11-26

290

Prostacyclin mediates endothelial COX-2-dependent neuroprotective effects during excitotoxic brain injury  

PubMed Central

In a previous study, we found that intracerebral administration of excitotoxin (RS)-(tetrazole-5yl) glycine caused increased neural damage in the brain in an endothelial COX-2 deleted mouse line (Tie2Cre COX-2flox/flox). In this study, we investigated whether prostacyclin might mediate this endothelial COX-2-dependent neuroprotection. Administration of excitotoxin into the striatum induced the production of prostacyclin (PGI2) in wild type, but not in endothelial COX-2 deleted mice. Inhibition of PGI2 synthase exacerbated brain lesions induced by the excitotoxin in wild type, but not in endothelial COX-2 deleted mice. Administration of a PGI2 agonist reduced neural damage in both wild type and endothelial COX-2 deleted mice. Increased PGI2 synthase expression was found in infiltrating neutrophils. In an ex vivo assay, PGI2 reduced the excitotoxin-induced calcium influx into neurons, suggesting a cellular mechanism for PGI2 mediated neuroprotection. These results reveal that PGI2 mediates endothelial COX-2 dependent neuroprotection. PMID:24971026

An, Ying; Belevych, Natalya; Wang, Yufen; Zhang, Hao; Nasse, Jason S; Herschman, Harvey; Chen, Qun; Tarr, Andrew; Liu, Xiaoyu; Quan, Ning

2014-01-01

291

Selective Serotonin Reuptake Inhibitor (SSRI) Antidepressants, Prolactin and Breast Cancer  

PubMed Central

Selective serotonin reuptake inhibitors (SSRIs) are a widely prescribed class of antidepressants. Laboratory and epidemiologic evidence suggests that a prolactin-mediated mechanism secondary to increased serotonin levels at neuronal synapses could lead to a potentially carcinogenic effect of SSRIs. In this population-based case-control study, we evaluated the association between SSRI use and breast cancer risk as a function of their relative degree of inhibition of serotonin reuptake as a proxy for their impact on prolactin levels. Cases were 2,129 women with primary invasive breast cancer diagnosed from 2003 to 2007, and controls were 21,297 women randomly selected from the population registry. Detailed information for each SSRI prescription dispensed was compiled using the Saskatchewan prescription database. Logistic regression was used to evaluate the impact of use of high and lower inhibitors of serotonin reuptake and duration of use, as well as to assess the effect of individual high inhibitors on the risk of breast cancer. Exclusive users of high or lower inhibitors of serotonin reuptake were not at increased risk for breast cancer compared with non-users of SSRIs (OR?=?1.01, CI?=?0.88–1.17 and OR?=?0.91, CI?=?0.67–1.25 respectively), regardless of their duration of use or menopausal status. While we cannot rule out the possibility of a clinically important risk increase (OR?=?1.83, CI?=?0.99–3.40) for long-term users of sertraline (?24 prescriptions), given the small number of exposed cases (n?=?12), the borderline statistical significance, and the wide confidence interval, these results need to be interpreted cautiously. In this large population-based case-control study, we found no conclusive evidence of breast cancer risk associated with the use of SSRIs even after assessing the degree of serotonin reuptake inhibition and duration of use. Our results do not support the serotonin-mediated pathway for the prolactin-breast cancer hypothesis. PMID:23227451

Ashbury, Janet E.; Lévesque, Linda E.; Beck, Patricia A.; Aronson, Kristan J.

2012-01-01

292

Celosomy is associated with prenatal exposure to cyclooxygenase inhibitors.  

PubMed

Celosomy is a term used for a group of congenital anomalies characterized by opening of the somatic wall with evisceration. The most common types of celosomy are gastroschisis and omphalocele. They have been associated with maternal age, cigarette smoking, environmental pollution, as well as prenatal exposure to vasoconstrictors and recreational drugs. The aim of this study was to evaluate the effect of prenatal exposure to various selective and non-selective cyclooxygenase-2 (COX-2) inhibitors on the abdominal wall defects in rat. A retrospective statistical analysis was performed on the basis of data collected in our laboratory in the years 1997-2004, during different teratological studies with COX-inhibitors (aspirin, DFU, DuP-697, ibuprofen, paracetamol, piroxicam, propyphenazone, tolmetin). Out of 6744 live born fetuses celosomy was revealed only in four animals exposed to different non-selective COX inhibitors. A single case of gastroschisis was also found in a rat exposed to the selective COX-2 inhibitor. The fetal body weight was significantly lower in COX-exposed group of fetuses when compared with untreated control. It was also significantly decreased in non-malformed fetuses prenatally exposed to COX inhibitors when compared with untreated control. The fetal body weight and length were lower in fetuses born with gastroschisis than with omphalocele. However, when animals with both anomalies were pooled in one group the mean fetal body weight was marginally lower (p = 0.0523) when compared with non-malformed group, while no statistically significant differences were found for fetal length. The pooled statistical analysis done for the concurrent and our own historic data showed that only aspirin statistically increased the risk of abdominal wall defects in rat fetuses. The expected ratio for aspirin is 56.41 per 10,000 offsprings (p < 0.05), which is over 10-times higher than ratio for all non-selective COX inhibitors, including aspirin (6.01/10,000; p < 0.05). No differences were found for selective COX-2 inhibitors. It could be stressed that aspirin, unlike other non-selective and selective COX-2 inhibitors increases the risk of the abdominal wall defects, which are observed more often in growth-retarded fetuses. PMID:16460959

Burdan, Franciszek; Szumilo, Justyna; Dudka, Jaroslaw; Korobowicz, Agnieszka; Klepacz, Robert

2006-03-01

293

COX-2 mediated induction of endothelium-independent contraction to bradykinin in endotoxin-treated porcine coronary artery.  

PubMed

This study examined the vascular effects of bradykinin in health and vascular inflammation comparing responses of isolated pig coronary arteries in the absence and presence of endotoxins. Bradykinin induced contractions in lipopolysaccharide-treated, but not untreated, arterial rings without endothelium. The B2-receptor antagonist HOE140, but not the B1-receptor inhibitor SSR240612, blocked these endothelium-independent contractions in response to bradykinin. The bradykinin-induced contractions were blocked by indomethacin, celecoxib, and terbogrel but not valeryl salicylate, AH6809, AL 8810, or RO1138452. They were attenuated by N-(p-amylcinnamoyl) anthranilic acid, and by diethyldithiocarbamate plus tiron but not by L-NAME. Quantitative reverse-transcription polymerase chain reaction revealed significant upregulations of messenger RNA expressions of B1 receptors, COX-2, and thromboxane A synthase 1 (TBXAS1) following lipopolysaccharide incubation but not of B2 receptors or COX-1. The present data demonstrate that bradykinin induces contractions mediated by the COX-2 pathway in endotoxin-treated pig coronary arteries. These results support differential roles of bradykinin in health and disease. PMID:25192543

More, Amar S; Kim, Hye Min; Zhao, Ru; Khang, Gilson; Hildebrandt, Tobias; Bernlöhr, Christian; Doods, Henri; Lee, Dongwon; Lee, Seung Hee; Vanhoutte, Paul M; Wu, Dongmei

2014-09-01

294

Structure-activity relationship of indomethacin analogues for MRP-1, COX-1 and COX-2 inhibition. identification of novel chemotherapeutic drug resistance modulators.  

PubMed

We report the screening of analogues of indomethacin to investigate the structure-activity relationship (SAR) of indomethacin-mediated multidrug resistance associated protein-1 (MRP-1) inhibition. By examining the activities of compounds with minor variations of the parent structure, we were able to separate MRP-1, glutathione-S-transferase (GST), cyclooxygenase (COX)-1 and COX-2 inhibitory activities. Combination cytotoxicity assays were utilised to identify agents which possess synergistic potential in MRP-1-expressing cell lines. MRP-1 Inside Out Vesicles (IOVs) were utilised to demonstrate the ability of the indomethacin analogues to inhibit the pump directly. Most of the indomethacin analogues active as MRP-1 inhibitors were poor GST inhibitors when compared with the GST-inhibitory activity of indomethacin. Two of the MRP-1 inhibitory analogues were found to have no COX-1 inhibitory activity and low COX-2 inhibitory activity, suggesting potentially reduced clinical toxicity. One MRP-1 inhibitory indomethacin analogue was also found to have low COX-1 inhibitory activity, but significant COX-2 inhibitory activity, making this analogue again interesting in terms of low potential toxicity, but with the possibility of direct inhibitory effects on tumour growth. PMID:12142058

Touhey, S; O'Connor, R; Plunkett, S; Maguire, A; Clynes, M

2002-08-01

295

NDRG2 Controls COX-2/PGE2-Mediated Breast Cancer Cell Migration and Invasion  

PubMed Central

N-myc downstream-regulated gene 2 (NDRG2), which is known to have tumor suppressor functions, is frequently down-regulated in breast cancers and potentially involved in preventing the migration and invasion of malignant tumor cells. In the present study, we examined the inhibitory effects of NDRG2 overexpression, specifically focusing on the role of cyclooxygenase-2 (COX-2) in the migration of breast cancer cells. NDRG2 overexpression in MDA-MB-231 cells inhibited the expression of the COX-2 mRNA and protein, the transcriptional activity of COX-2, and prostaglandin E2 (PGE2) production, which were induced by a treatment with phorbol-12-myristate-13-acetate (PMA). Nuclear transcription factor-?B (NF-?B) signaling attenuated by NDRG2 expression resulted in a decrease in PMA-induced COX-2 expression. Interestingly, the inhibition of COX-2 strongly suppressed PMA-stimulated migration and invasion in MDA-MB-231-NDRG2 cells. Moreover, siRNA-mediated knockdown of NDRG2 in MCF7 cells increased the COX-2 mRNA and protein expression levels and the PMA-induced COX-2 expression levels. Consistent with these results, the migration and invasion of MCF7 cells treated with NDRG2 siRNA were significantly enhanced following treatment with PMA. Taken together, our data show that the inhibition of NF-?B signaling by NDRG2 expression is able to suppress cell migration and invasion through the down-regulation of COX-2 expression. PMID:25256221

Kim, Myung-Jin; Kim, Hak-Su; Lee, Soo-Hwan; Yang, Young; Lee, Myeong-Sok; Lim, Jong-Seok

2014-01-01

296

NDRG2 controls COX-2/PGE?-mediated breast cancer cell migration and invasion.  

PubMed

N-myc downstream-regulated gene 2 (NDRG2), which is known to have tumor suppressor functions, is frequently down-regulated in breast cancers and potentially involved in preventing the migration and invasion of malignant tumor cells. In the present study, we examined the inhibitory effects of NDRG2 overexpression, specifically focusing on the role of cyclooxygenase-2 (COX-2) in the migration of breast cancer cells. NDRG2 overexpression in MDA-MB-231 cells inhibited the expression of the COX-2 mRNA and protein, the transcriptional activity of COX-2, and prostaglandin E2 (PGE2) production, which were induced by a treatment with phorbol-12-myristate-13-acetate (PMA). Nuclear transcription factor-?B (NF-?B) signaling attenuated by NDRG2 expression resulted in a decrease in PMA-induced COX-2 expression. Interestingly, the inhibition of COX-2 strongly suppressed PMA-stimulated migration and invasion in MDA-MB-231-NDRG2 cells. Moreover, siRNA-mediated knockdown of NDRG2 in MCF7 cells increased the COX-2 mRNA and protein expression levels and the PMA-induced COX-2 expression levels. Consistent with these results, the migration and invasion of MCF7 cells treated with NDRG2 siRNA were significantly enhanced following treatment with PMA. Taken together, our data show that the inhibition of NF-?B signaling by NDRG2 expression is able to suppress cell migration and invasion through the down-regulation of COX-2 expression. PMID:25256221

Kim, Myung-Jin; Kim, Hak-Su; Lee, Soo-Hwan; Yang, Young; Lee, Myeong-Sok; Lim, Jong-Seok

2014-10-31

297

Exploring the molecular determinants of substrate-selective inhibition of cyclooxygenase-2 by lumiracoxib.  

PubMed

Lumiracoxib is a substrate-selective inhibitor of endocannabinoid oxygenation by cyclooxygenase-2 (COX-2). We assayed a series of lumiracoxib derivatives to identify the structural determinants of substrate-selective inhibition. The hydrogen-bonding potential of the substituents at the ortho positions of the aniline ring dictated the potency and substrate selectivity of the inhibitors. The presence of a 5'-methyl group on the phenylacetic acid ring increased the potency of molecules with a single ortho substituent. Des-fluorolumiracoxib (2) was the most potent and selective inhibitor of endocannabinoid oxygenation. The positioning of critical substituents in the binding site was identified from a 2.35Å crystal structure of lumiracoxib bound to COX-2. PMID:24060487

Windsor, Matthew A; Valk, Pieter L; Xu, Shu; Banerjee, Surajit; Marnett, Lawrence J

2013-11-01

298

ERK1/2/COX-2/PGE2 signaling pathway mediates GPR91-dependent VEGF release in streptozotocin-induced diabetes  

PubMed Central

Purpose Retinal vascular dysfunction caused by vascular endothelial growth factor (VEGF) is the major pathological change that occurs in diabetic retinopathy (DR). It has recently been demonstrated that G protein-coupled receptor 91 (GPR91) plays a major role in both vasculature development and retinal angiogenesis. In this study, we examined the signaling pathways involved in GPR91-dependent VEGF release during the early stages of retinal vascular change in streptozotocin-induced diabetes. Methods Diabetic rats were assigned randomly to receive intravitreal injections of shRNA lentiviral particles targeting GPR91 (LV.shGPR91) or control particles (LV.shScrambled). Accumulation of succinate was assessed by gas chromatography-mass spectrometry (GC-MS). At 14 weeks, the ultrastructure and function of the retinal vessels of diabetic retinas with or without shRNA treatment were assessed using hematoxylin and eosin (HE) staining, transmission electron microscopy (TEM), and Evans blue dye permeability. The expression of GPR91, extracellular signal-regulated kinases 1 and 2 (ERK1/2) and cyclooxygenase-2 (COX-2) were measured using immunofluorescence and western blotting. COX-2 and VEGF mRNA were determined by quantitative RT–PCR. Prostaglandin E2 (PGE2) and VEGF secretion were detected using an enzyme-linked immunosorbent assay. Results Succinate exhibited abundant accumulation in diabetic rat retinas. The retinal telangiectatic vessels, basement membrane thickness, and Evans blue dye permeability were attenuated by treatment with GPR91 shRNA. In diabetic rats, knockdown of GPR91 inhibited the activities of ERK1/2 and COX-2 as well as the expression of PGE2 and VEGF. Meanwhile, COX-2, PGE2, and VEGF expression was inhibited by ERK1/2 inhibitor U0126 and COX-2 inhibitor NS-398. Conclusions Our data suggest that hyperglycemia causes succinate accumulation and GPR91 activity in retinal ganglion cells, which mediate VEGF-induced retinal vascular change via the ERK1/2/COX-2/PGE2 pathway. This study highlights the signaling pathway as a potential target for intervention in DR. PMID:25324681

Li, Tingting; Hu, Jianyan; Du, Shanshan; Chen, Yongdong; Wang, Shuai

2014-01-01

299

?9-THC-caused synaptic and memory impairments are mediated through COX-2 signaling.  

PubMed

Marijuana has been used for thousands of years as a treatment for medical conditions. However, untoward side effects limit its medical value. Here, we show that synaptic and cognitive impairments following repeated exposure to ?(9)-tetrahydrocannabinol (?(9)-THC) are associated with the induction of cyclooxygenase-2 (COX-2), an inducible enzyme that converts arachidonic acid to prostanoids in the brain. COX-2 induction by ?(9)-THC is mediated via CB1 receptor-coupled G protein ?? subunits. Pharmacological or genetic inhibition of COX-2 blocks downregulation and internalization of glutamate receptor subunits and alterations of the dendritic spine density of hippocampal neurons induced by repeated ?(9)-THC exposures. Ablation of COX-2 also eliminates ?(9)-THC-impaired hippocampal long-term synaptic plasticity, working, and fear memories. Importantly, the beneficial effects of decreasing ?-amyloid plaques and neurodegeneration by ?(9)-THC in Alzheimer's disease animals are retained in the presence of COX-2 inhibition. These results suggest that the applicability of medical marijuana would be broadened by concurrent inhibition of COX-2. PMID:24267894

Chen, Rongqing; Zhang, Jian; Fan, Ni; Teng, Zhao-Qian; Wu, Yan; Yang, Hongwei; Tang, Ya-Ping; Sun, Hao; Song, Yunping; Chen, Chu

2013-11-21

300

?9-THC-caused synaptic and memory impairments are mediated through COX-2 signaling  

PubMed Central

SUMMARY Marijuana has been used for thousands of years as a treatment for medical conditions. However, untoward side effects limit its medical value. Here we show that synaptic and cognitive impairments following repeated exposure to ?9-tetrahydrocannabinol (?9-THC) are associated with the induction of cyclooxygenase-2 (COX-2), an inducible enzyme that converts arachidonic acid to prostanoids, in the brain. COX-2 induction by ?9-THC is mediated via CB1 receptor-coupled G-protein ?? subunits. Pharmacological or genetic inhibition of COX-2 blocks down-regulation and internalization of glutamate receptor subunits and alterations of the dendritic spine density of hippocampal neurons induced by repeated ?9-THC exposures. Ablation of COX-2 also eliminates ?9-THC-impaired hippocampal long-term synaptic plasticity, spatial, and fear memories. Importantly, the beneficial effects of decreasing ?-amyloid plaques and neurodegeneration by ?9-THC in Alzheimer’s disease animals are retained in the presence of COX-2 inhibition. These results suggest that the applicability of medical marijuana would be broadened by concurrent inhibition of COX-2. PMID:24267894

Yang, Hongwei; Tang, Ya-ping; Sun, Hao; Song, Yunping; Chen, Chu

2013-01-01

301

Selective inhibitors of a PAF biosynthetic enzyme lysophosphatidylcholine acyltransferase 2.  

PubMed

Platelet-activating factor (PAF) is a potent pro-inflammatory phospholipid mediator. In response to extracellular stimuli, PAF is rapidly biosynthesized by lyso-PAF acetyltransferase (lyso-PAFAT). Previously, we identified two types of lyso-PAFATs: lysophosphatidylcholine acyltransferase (LPCAT)1, mostly expressed in the lungs where it produces PAF and dipalmitoyl-phosphatidylcholine essential for respiration, and LPCAT2, which biosynthesizes PAF and phosphatidylcholine (PC) in the inflammatory cells. Under inflammatory conditions, LPCAT2, but not LPCAT1, is activated and upregulated to produce PAF. Thus, it is important to develop inhibitors specific for LPCAT2 in order to ameliorate PAF-related inflammatory diseases. Here, we report the first identification of LPCAT2-specific inhibitors, N-phenylmaleimide derivatives, selected from a 174,000-compound library using fluorescence-based high-throughput screening followed by the evaluation of the effects on LPCAT1 and LPCAT2 activities, cell viability, and cellular PAF production. Selected compounds competed with acetyl-CoA for the inhibition of LPCAT2 lyso-PAFAT activity and suppressed PAF biosynthesis in mouse peritoneal macrophages stimulated with a calcium ionophore. These compounds had low inhibitory effects on LPCAT1 activity, indicating that adverse effects on respiratory functions may be avoided. The identified compounds and their derivatives will contribute to the development of novel drugs for PAF-related diseases and facilitate the analysis of LPCAT2 functions in phospholipid metabolism in vivo. PMID:24850807

Tarui, Megumi; Shindou, Hideo; Kumagai, Kazuo; Morimoto, Ryo; Harayama, Takeshi; Hashidate, Tomomi; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Nagase, Takahide; Shimizu, Takao

2014-05-21

302

Characterization of microsomal prostaglandin E synthase 1 inhibitors.  

PubMed

Microsomal prostaglandin E synthase-1 (mPGES-1) is an inducible terminal synthase in PGE2 biosynthesis by inflammatory and cancer cells. Clinical and experimental data emphasize that mPGES-1 might be a valuable target, with improved selectivity and safety compared to traditional NSAIDs or selective COX-2 inhibitors, in the treatment of inflammatory diseases, different types of cancer as well as central symptoms elicited by peripheral inflammation. Since the first characterization of mPGES-1, the numbers of publications on mPGES-1 structure, pathogenic role and inhibitor development have increased exponentially; however, there are currently no selective mPGES-1 inhibitors available for clinical use. In this MiniReview, we focus on recent advances in the development of selective inhibitors of mPGES-1 activity, with the aim to discuss the effects of targeting mPGES-1 in different inflammatory models in vitro and in vivo. PMID:24138533

Korotkova, Marina; Jakobsson, Per-Johan

2014-01-01

303

Antenatal Use of Selective Serotonin-Reuptake Inhibitors and QT Interval Prolongation in Newborns  

Microsoft Academic Search

OBJECTIVES.Prolongation of the QT interval is a risk factor for sudden death. Selective serotonin-reuptake inhibitor antidepressants can prolong the QT interval and are widely used by pregnant women. Whether antenatal exposure to selective serotonin- reuptake inhibitor causes QT prolongation in offspring is unknown. The aim of this study was to determine the effect of maternal use of selective serotonin-reuptake inhibitor

Gal Dubnov-Raz; David N. Juurlink; Rami Fogelman; Paul Merlob; Shinya Ito; Gideon Koren; Yaron Finkelstein

2010-01-01

304

Convergent synthesis and evaluation of 18F-labeled azulenic COX2 probes for cancer imaging  

PubMed Central

The overall objectives of this research are to (i) develop azulene-based positron emission tomography (PET) probes and (ii) image COX2 as a potential biomarker of breast cancer. Several lines of research have demonstrated that COX2 is overexpressed in breast cancer and that its presence correlates with poor prognoses. While other studies have reported that COX2 inhibition can be modulated and used beneficially as a chemopreventive strategy in cancer, no viable mechanism for achieving that approach has yet been developed. This shortfall could be circumvented through in vivo imaging of COX2 activity, particularly using sensitive imaging techniques such as PET. Toward that goal, our laboratory focuses on the development of novel 18F-labled COX2 probes. We began the synthesis of the probes by transforming tropolone into a lactone, which was subjected to an [8 + 2] cycloaddition reaction to yield 2-methylazulene as the core ring of the probe. After exploring numerous synthetic routes, the final target molecule and precursor PET compounds were prepared successfully using convergent synthesis. Conventional 18F labeling methods caused precursor decomposition, which prompted us to hypothesize that the acidic protons of the methylene moiety between the azulene and thiazole rings were readily abstracted by a strong base such as potassium carbonate. Ultimately, this caused the precursors to disintegrate. This observation was supported after successfully using an 18F labeling strategy that employed a much milder phosphate buffer. The 18F-labeled COX2 probe was tested in a breast cancer xenograft mouse model. The data obtained via successive whole-body PET/CT scans indicated probe accumulation and retention in the tumor. Overall, the probe was stable in vivo and no defluorination was observed. A biodistribution study and Western blot analysis corroborate with the imaging data. In conclusion, this novel COX2 PET probe was shown to be a promising agent for cancer imaging and deserves further investigation. PMID:23316477

Nolting, Donald D.; Nickels, Michael; Tantawy, Mohammed N.; Yu, James Y. H.; Xie, Jingping; Peterson, Todd E.; Crews, Brenda C.; Marnett, Larry; Gore, John C.; Pham, Wellington

2013-01-01

305

A Selective Phenelzine Analogue Inhibitor of Histone Demethylase LSD1  

PubMed Central

Lysine-specific demethylase 1 (LSD1) is an epigenetic enzyme that oxidatively cleaves methyl groups from monomethyl and dimethyl Lys4 of histone H3 (H3K4Me1, H3K4Me2) and can contribute to gene silencing. This study describes the design and synthesis of analogues of a monoamine oxidase antidepressant, phenelzine, and their LSD1 inhibitory properties. A novel phenelzine analogue (bizine) containing a phenyl-butyrylamide appendage was shown to be a potent LSD1 inhibitor in vitro and was selective versus monoamine oxidases A/B and the LSD1 homologue, LSD2. Bizine was found to be effective at modulating bulk histone methylation in cancer cells, and ChIP-seq experiments revealed a statistically significant overlap in the H3K4 methylation pattern of genes affected by bizine and those altered in LSD1?/? cells. Treatment of two cancer cell lines, LNCaP and H460, with bizine conferred a reduction in proliferation rate, and bizine showed additive to synergistic effects on cell growth when used in combination with two out of five HDAC inhibitors tested. Moreover, neurons exposed to oxidative stress were protected by the presence of bizine, suggesting potential applications in neurodegenerative disease. PMID:24707965

Prusevich, Polina; Kalin, Jay H.; Ming, Shonoi A.; Basso, Manuela; Givens, Jeffrey; Li, Xin; Hu, Jianfei; Taylor, Martin S.; Cieniewicz, Anne M.; Hsiao, Po-Yuan; Huang, Rong; Roberson, Heather; Adejola, Nkosi; Avery, Lindsay B.; Casero, Robert A.; Taverna, Sean D.; Qian, Jiang; Tackett, Alan J.; Ratan, Rajiv R.; McDonald, Oliver G.; Feinberg, Andrew P.; Cole, Philip A.

2014-01-01

306

Discovery of Selective Inhibitors of the Clostridium difficile Dehydroquinate Dehydratase  

PubMed Central

A vibrant and healthy gut flora is essential for preventing the proliferation of Clostridium difficile, a pathogenic bacterium that causes severe gastrointestinal symptoms. In fact, most C. difficile infections (CDIs) occur after broad-spectrum antibiotic treatment, which, by eradicating the commensal gut bacteria, allows its spores to proliferate. Hence, a C. difficile specific antibiotic that spares the gut flora would be highly beneficial in treating CDI. Towards this goal, we set out to discover small molecule inhibitors of the C. difficile enzyme dehydroquinate dehydratase (DHQD). DHQD is the 3rd of seven enzymes that compose the shikimate pathway, a metabolic pathway absent in humans, and is present in bacteria as two phylogenetically and mechanistically distinct types. Using a high-throughput screen we identified three compounds that inhibited the type I C. difficile DHQD but not the type II DHQD from Bacteroides thetaiotaomicron, a highly represented commensal gut bacterial species. Kinetic analysis revealed that the compounds inhibit the C. difficile enzyme with Ki values ranging from 10 to 20 µM. Unexpectedly, kinetic and biophysical studies demonstrate that inhibitors also exhibit selectivity between type I DHQDs, inhibiting the C. difficile but not the highly homologous Salmonella enterica DHQD. Therefore, the three identified compounds seem to be promising lead compounds for the development of C. difficile specific antibiotics. PMID:24586713

Anderson, Wayne F.; Caffrey, Michael; Lavie, Arnon

2014-01-01

307

Inhibition of phorbol ester-induced COX-2 expression by some edible African plants.  

PubMed

Cancer bush (CB, Sutherlandia frutescens), Devil's claw (DEV, Harpagophytum procumbens), Rooibos tea (RT, Aspalathus linearis), and Bambara groundnut (BB, Vignea subterranean) have been used to treat some malignancies and inflammatory disorders in Africa. However, biochemical basis for chemopreventive effects of these medicinal plants remains unclear. An abnormally elevated expression of cyclooxygenase-2 (COX-2) has been implicated in pathogenesis and progression of carcinogenesis. In the present study, we found that the methanol extracts of CB, DEV, RT, and BB inhibited, to a different extent, 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced COX-2 expression in human breast epithelial (MCF10A) cells and in mouse skin in vivo. To determine the molecular mechanism of COX-2 inhibition by the above medicinal plants, we examined their effects on activation of NF-kappaB which is one of the major transcription factors responsible for regulating COX-2 expression. Methanol extracts of both CB and BB inhibited the DNA binding of NF-kappaB activated by TPA in MCF10A cells in a dose-dependent manner. Based on above findings, CB and BB are likely to inhibit TPA-induced COX-2 expression through suppression of DNA binding of NF-kappaB, which may contribute to the chemopreventive or chemoprotective activity of these African plants. PMID:15630188

Na, Hye-Kyung; Mossanda, Kensese S; Lee, Ji-Yoon; Surh, Young-Joon

2004-01-01

308

Cyclooxygenase inhibitors: From pharmacology to clinical read-outs.  

PubMed

Acetylsalicylic acid (aspirin) is a prototypic cyclooxygenase (COX) inhibitor. It was synthesized serendipitously from a natural compound, i.e., salicylic acid, with known analgesic activity. This chemical modification, obtained for the first time in an industrial environment in 1897, endowed aspirin with the unique capacity of acetylating and inactivating permanently COX-isozymes. Traditional nonsteroidal anti-inflammatory drugs (tNSAIDs) were developed to mimic the pharmacological effects of aspirin, using aspirin-sensitive experimental models of pain and inflammation as the template for screening new chemical entities. Among the tNSAIDs, some were endowed with moderate COX- selectivity (e.g., diclofenac), but no studies of sufficient size and duration were performed to show any clinically relevant difference between different members of the class. Similarly, no serious attempts were made to unravel the mechanisms involved in the shared therapeutic and toxic effects of tNSAIDs until the discovery of COX-2. This led to characterizing their main therapeutic effects as being COX-2-dependent and their gastrointestinal (GI) toxicity as being COX-1-dependent, and provided a rationale for developing a new class of selective COX-2 inhibitors, the coxibs. This review will discuss the clinical pharmacology of tNSAIDs and coxibs, and the clinical read-outs of COX-isozyme inhibition. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance." PMID:25263946

Patrignani, Paola; Patrono, Carlo

2014-09-28

309

Enrichment of Echinacea angustifolia with Bauer alkylamide 11 and Bauer ketone 23 increased anti-inflammatory potential through interfering with COX-2 enzyme activity  

PubMed Central

Bauer alkylamide 11 and ketone 23 were partially responsible for Echinacea angustifolia anti-inflammatory properties previously. This study further tested their importance using the inhibition of prostaglandin E2 (PGE2) and nitric oxide (NO) production by RAW264.7 mouse macrophages in the absence and presence of lipopolysaccharide (LPS) and E. angustifolia extracts, phytochemical enriched fractions, or pure synthesized standards. Molecular targets were probed using microarray, qRT-PCR, western blot, and enzyme assays. Fractions with these phytochemicals were more potent inhibitors of LPS induced PGE2 production than E. angustifolia extracts. Microarray did not detect changes in transcripts with phytochemical treatments; however qRT-PCR showed decrease in TNF-? and increase of iNOS transcripts. LPS induced COX-2 protein was increased by an E. angustifolia fraction containing Bauer ketone 23 and by pure phytochemical. COX-2 activity was decreased with all treatments. The phytochemical inhibition of PGE2 production by Echinacea may be due to the direct targeting of COX-2 enzyme. PMID:20681645

LaLone, Carlie A.; Huang, Nan; Rizshsky, Ludmila; Yum, Man-Yu; Singh, Navrozedeep; Hauck, Cathy; Nikolau, Basil J.; Wurtele, Eve S.; Kohut, Marian L.; Murphy, Patricia A.; Birt, Diane F.

2013-01-01

310

Enrichment of Echinacea angustifolia with Bauer alkylamide 11 and Bauer ketone 23 increased anti-inflammatory potential through interference with cox-2 enzyme activity.  

PubMed

Bauer alkylamide 11 and Bauer ketone 23 were previously found to be partially responsible for Echinacea angustifolia anti-inflammatory properties. This study further tested their importance using the inhibition of prostaglandin E(2) (PGE(2)) and nitric oxide (NO) production by RAW264.7 mouse macrophages in the absence and presence of lipopolysaccharide (LPS) and E. angustifolia extracts, phytochemical enriched fractions, or pure synthesized standards. Molecular targets were probed using microarray, qRT-PCR, Western blot, and enzyme assays. Fractions with these phytochemicals were more potent inhibitors of LPS-induced PGE(2) production than E. angustifolia extracts. Microarray did not detect changes in transcripts with phytochemical treatments; however, qRT-PCR showed a decrease in TNF-alpha and an increase of iNOS transcripts. LPS-induced COX-2 protein was increased by an E. angustifolia fraction containing Bauer ketone 23 and by pure phytochemical. COX-2 activity was decreased with all treatments. The phytochemical inhibition of PGE(2) production by Echinacea may be due to the direct targeting of COX-2 enzyme. PMID:20681645

Lalone, Carlie A; Huang, Nan; Rizshsky, Ludmila; Yum, Man-Yu; Singh, Navrozedeep; Hauck, Cathy; Nikolau, Basil J; Wurtele, Eve S; Kohut, Marian L; Murphy, Patricia A; Birt, Diane F

2010-08-11

311

Antinociceptive effect of tetrandrine on LPS-induced hyperalgesia via the inhibition of IKK? phosphorylation and the COX-2/PGE? pathway in mice.  

PubMed

Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid that is isolated from the Stephania Tetrandra. It is known to possess anti-inflammatory and immunomodulatory effects. We have shown that TET can effectively suppress the production of bacterial lipopolysaccharide (LPS)-induced inflammatory mediators, including cyclooxygenases (COXs), in macrophages. However, whether TET has an antinociceptive effect on LPS-induced hyperalgesia is unknown. In the present study, we investigated the potential antinociceptive effects of TET and the mechanisms by which it elicits its effects on LPS-induced hyperalgesia. LPS effectively evoked hyperalgesia and induced the production of PGE2 in the sera, brain tissues, and cultured astroglia. TET pretreatment attenuated all of these effects. LPS also activated inhibitor of ?B (I?B) kinase ? (IKK?) and its downstream components in the I?B/nuclear factor (NF)-?B signaling pathway, including COX-2; the increase in expression levels of these components was significantly abolished by TET. Furthermore, in primary astroglia, knockdown of IKK?, but not IKK?, reversed the effects of TET on the LPS-induced increase in I?B phosphorylation, P65 phosphorylation, and COX-2. Our results suggest that TET can effectively exert antinociceptive effects on LPS-induced hyperalgesia in mice by inhibiting IKK? phosphorylation, which leads to the reduction in the production of important pain mediators, such as PGE2 and COX-2, via the IKK?/I?B/NF-?B pathway. PMID:24722146

Zhao, Hengguang; Luo, Fuling; Li, Hongzhong; Zhang, Li; Yi, Yongfen; Wan, Jingyuan

2014-01-01

312

The RNA editing pattern of cox2 mRNA is affected by point mutations in plant mitochondria.  

PubMed

The mitochondrial transcriptome from land plants undergoes hundreds of specific C-to-U changes by RNA editing. These events are important since most of them occur in the coding region of mRNAs. One challenging question is to understand the mechanism of recognition of a selected C residue (editing sites) on the transcript. It has been reported that a short region surrounding the target C forms the cis-recognition elements, but individual residues on it do not play similar roles for the different editing sites. Here, we studied the role of the -1 and +1 nucleotide in wheat cox2 editing site recognition using an in organello approach. We found that four different recognition patterns can be distinguished: (a) +1 dependency, (b) -1 dependency, (c) +1/-1 dependency, and (d) no dependency on nearest neighbor residues. A striking observation was that whereas a 23 nt cis region is necessary for editing, some mutants affect the editing efficiency of unmodified distant sites. As a rule, mutations or pre-edited variants of the transcript have an impact on the complete set of editing targets. When some Cs were changed into Us, the remaining editing sites presented a higher efficiency of C-to-U conversion than in wild type mRNA. Our data suggest that the complex response observed for cox2 mRNA may be a consequence of the fate of the transcript during mitochondrial gene expression. PMID:21695137

Castandet, Benoît; Araya, Alejandro

2011-01-01

313

Characterization of a Selective Inhibitor of Inositol Hexakisphosphate Kinases  

PubMed Central

Inositol hexakisphosphate kinases (IP6Ks) phosphorylate inositol hexakisphosphate (InsP6) to yield 5-diphosphoinositol pentakisphosphate (5-[PP]-InsP5 or InsP7). In this study, we report the characterization of a selective inhibitor, N2-(m-(trifluoromethy)lbenzyl) N6-(p-nitrobenzyl)purine (TNP), for these enzymes. TNP dose-dependently and selectively inhibited the activity of IP6K in vitro and inhibited InsP7 and InsP8 synthesis in vivo without affecting levels of other inositol phosphates. TNP did not inhibit either human or yeast Vip/PPIP5K, a newly described InsP6/InsP7 1/3-kinase. Overexpression of IP6K1, -2, or -3 in cells rescued TNP inhibition of InsP7 synthesis. TNP had no effect on the activity of a large number of protein kinases, suggesting that it is selective for IP6Ks. TNP reversibly reduced InsP7/InsP8 levels. TNP in combination with genetic studies was used to implicate the involvement of two pathways for synthesis of InsP8 in yeast. TNP induced a fragmented vacuole phenotype in yeast, consistent with inhibition of Kcs1, a Saccharomyces cerevisiae IP6K. In addition, it also inhibited insulin release from Min6 cells in a dose-dependent manner further implicating InsP7 in this process. TNP thus provides a means of selectively and rapidly modulating cellular InsP7 levels, providing a new and versatile tool to study the biological function and metabolic relationships of inositol pyrophosphates. PMID:19208622

Padmanabhan, Usha; Dollins, D. Eric; Fridy, Peter C.; York, John D.; Downes, C. Peter

2009-01-01

314

Cyclopamine and jervine induce COX-2 overexpression in human erythroleukemia cells but only cyclopamine has a pro-apoptotic effect  

SciTech Connect

Erythroleukemia is generally associated with a very poor response and survival to current available therapeutic agents. Cyclooxygenase-2 (COX-2) has been described to play a crucial role in the proliferation and differentiation of leukemia cells, this enzyme seems to play an important role in chemoresistance in different cancer types. Previously, we demonstrated that diosgenin, a plant steroid, induced apoptosis in HEL cells with concomitant COX-2 overexpression. In this study, we investigated the antiproliferative and apoptotic effects of cyclopamine and jervine, two steroidal alkaloids with similar structures, on HEL and TF1a human erythroleukemia cell lines and, for the first time, their effect on COX-2 expression. Cyclopamine, but not jervine, inhibited cell proliferation and induced apoptosis in these cells. Both compounds induced COX-2 overexpression which was responsible for apoptosis resistance. In jervine-treated cells, COX-2 overexpression was NF-?B dependent. Inhibition of NF-?B reduced COX-2 overexpression and induced apoptosis. In addition, cyclopamine induced apoptosis and COX-2 overexpression via PKC activation. Inhibition of the PKC pathway reduced both apoptosis and COX-2 overexpression in both cell lines. Furthermore, we demonstrated that the p38/COX-2 pathway was involved in resistance to cyclopamine-induced apoptosis since p38 inhibition reduced COX-2 overexpression and increased apoptosis in both cell lines. - Highlights: ? Cyclopamine alone but not jervine induces apoptosis in human erythroleukemia cells. ? Cyclopamine and jervine induce COX-2 overexpression. ? COX-2 overexpression is implicated in resistance to cyclopamine-induced apoptosis. ? Apoptotic potential of jervine is restrained by NF-?B pathway activation. ? PKC is involved in cyclopamine-induced apoptosis and COX-2 overexpression.

Ghezali, Lamia; Leger, David Yannick; Limami, Youness [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Cook-Moreau, Jeanne [Université de Limoges, FR 3503 GEIST, UMR CNRS 7276 “Contrôle de la réponse immune B et lymphoproliférations”, Faculté de Médecine, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Beneytout, Jean-Louis [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Liagre, Bertrand, E-mail: bertrand.liagre@unilim.fr [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France)

2013-04-15

315

Scaffold hopping approach on the route to selective tankyrase inhibitors.  

PubMed

A virtual screening procedure was applied to identify new tankyrase inhibitors. Through pharmacophore screening of a compounds collection from the SPECS database, the methoxy[l]benzothieno[2,3-c]quinolin-6(5H)-one scaffold was identified as nicotinamide mimetic able to inhibit tankyrase activity at low micromolar concentration. In order to improve potency and selectivity, tandem structure-based and scaffold hopping approaches were carried out over the new scaffold leading to the discovery of the 2-(phenyl)-3H-benzo[4,5]thieno[3,2-d]pyrimidin-4-one as powerful chemotype suitable for tankyrase inhibition. The best compound 2-(4-tert-butyl-phenyl)-3H-benzo[4,5]thieno[3,2-d]pyrimidin-4-one (23) displayed nanomolar potencies (IC50s TNKS-1 = 21 nM and TNKS-2 = 29 nM) and high selectivity when profiled against several other PARPs. Furthermore, a striking Wnt signaling, as well as cell growth inhibition, was observed assaying 23 in DLD-1 cancer cells. PMID:25299683

Liscio, Paride; Carotti, Andrea; Asciutti, Stefania; Ferri, Martina; Pires, Maira M; Valloscuro, Sara; Ziff, Jacob; Clark, Neil R; Macchiarulo, Antonio; Aaronson, Stuart A; Pellicciari, Roberto; Camaioni, Emidio

2014-11-24

316

EPAC2-mediated calreticulin regulates LIF and COX2 expression in human endometrial glandular cells.  

PubMed

The proper production of the implantation-related factors, leukemia inhibitory factor (LIF), cyclooxygenase 2 (COX2, PTGS2), and prostaglandin E2 (PGE2) in the uterine glands is essential for embryo implantation and the establishment of endometrial receptivity. It has been shown that cAMP-mediated protein kinase A (PKA) signaling regulates the production of these factors. We have previously reported that exchange protein directly activated by cAMP 2 (EPAC2, RAPGEF4), another cAMP mediator, is involved in the differentiation of endometrial stromal cells through the regulation of the expression of calreticulin (CALR). To address whether EPAC2-CALR signaling is involved in the expression of implantation-related factors, we examined the effect of EPAC2 and CALR knockdown on their expression in cultured human endometrial glandular epithelial EM1 cells, treated with forskolin, an adenylyl cyclase activator, an EPAC-selective cAMP analog (8-(4-chlorophenylthio)-2'-O-methyl cAMP (CPT)), or a PKA-selective cAMP analog (N(6)-phenyl-cAMP (Phe)). In addition, the status of cell senescence was examined. EPAC2 knockdown suppressed the expression of CALR protein and mRNA in EM1 cells. Forskolin- or Phe-, but not CPT-, induced expression of LIF or PTGS2 and secretion of PGE2 was inhibited in EPAC2- or CALR-silenced EM1 cells. In addition, knockdown of EPAC2 or CALR increased senescence-associated beta galactosidase activity and expression of p21 but decreased expression of p53. These findings indicate that expression of CALR regulated by EPAC2 in endometrial glandular epithelial cells is critical for the expression of LIF and PTGS2-mediated production of PGE2 through cAMP signaling. Furthermore, EPAC2 and CALR could play a role in the maintenance of gland function. PMID:25378661

Kusama, Kazuya; Yoshie, Mikihiro; Tamura, Kazuhiro; Imakawa, Kazuhiko; Tachikawa, Eiichi

2015-02-01

317

Curcumin Alleviates Neuropathic Pain by Inhibiting p300/CBP Histone Acetyltransferase Activity-Regulated Expression of BDNF and Cox-2 in a Rat Model  

PubMed Central

The management of neuropathic pain is still a major challenge because of its unresponsiveness to most common treatments. Curcumin has been reported to play an active role in the treatment of various neurological disorders, such as neuropathic pain. Curcumin has long been recognized as a p300/CREB-binding protein (CBP) inhibitor of histone acetyltransferase (HAT) activity. However, this mechanism has never been investigated for the treatment of neuropathic pain with curcumin. The aim of the present study was to investigate the anti-nociceptive role of curcumin in the chronic constriction injury (CCI) rat model of neuropathic pain. Furthermore, with this model we investigated the effect of curcumin on P300/CBP HAT activity-regulated release of the pro-nociceptive molecules, brain-derived neurotrophic factor (BDNF) and cyclooxygenase-2 (Cox-2). Treatment with 40 and 60 mg/kg body weight curcumin for 7 consecutive days significantly attenuated CCI-induced thermal hyperalgesia and mechanical allodynia, whereas 20 mg/kg curcumin showed no significant analgesic effect. Chromatin immunoprecipitation analysis revealed that curcumin dose-dependently reduced the recruitment of p300/CBP and acetyl-Histone H3/acetyl-Histone H4 to the promoter of BDNF and Cox-2 genes. A similar dose-dependent decrease of BDNF and Cox-2 in the spinal cord was also observed after curcumin treatment. These results indicated that curcumin exerted a therapeutic role in neuropathic pain by down-regulating p300/CBP HAT activity-mediated gene expression of BDNF and Cox-2. PMID:24603592

Zhu, Xiaoyan; Li, Qian; Chang, Ruimin; Yang, Dong; Song, Zongbing; Guo, Qulian; Huang, Changsheng

2014-01-01

318

Ethyl caffeate suppresses NF-?B activation and its downstream inflammatory mediators, iNOS, COX-2, and PGE2 in vitro or in mouse skin  

PubMed Central

Ethyl caffeate, a natural phenolic compound, was isolated from Bidens pilosa, a medicinal plant popularly used for treating certain inflammatory syndromes. The purpose of this study was to investigate the structural activity, and the anti-inflammatory functions and mechanism(s) of ethyl caffeate. Ethyl caffeate was found to markedly suppress the lipopolysaccharide (LPS)-induced nitric oxide (NO) production (IC50=5.5??g?ml?1), mRNA and protein expressions of inducible nitric oxide synthase (iNOS), and prostaglandin E2 (PGE2) production in RAW 264.7 macrophages. Transient gene expression assays using human cox-2 promoter construct revealed that ethyl caffeate exerted an inhibitory effect on cox-2 transcriptional activity in 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated MCF-7 cells. Immunohistochemical studies of mouse skin demonstrated that TPA-induced COX-2 expression was significantly inhibited by ethyl caffeate with a superior effect to that of celecoxib, a nonsteroidal anti-inflammatory drug. The phosphorylation and degradation of inhibitor ?B (I?B) and the translocation of nuclear transcription factor-?B (NF-?B) into the nucleus, as well as the activation of mitogen-activated protein kinases (MAPKs) induced by LPS in macrophages, were not affected by ethyl caffeate. Ethyl caffeate, however, could inhibit NF-?B activation by impairing the binding of NF-?B to its cis-acting element. These results suggest that ethyl caffeate suppresses iNOS and COX-2 expressions partly through the inhibition of the NF-?B·DNA complex formation. Structure–activity relationship analyses suggested that the catechol moiety and ?,?-unsaturated ester group in ethyl caffeate are important and essential structural features for preventing NF-?B·DNA complex formation. This study provides an insight into the probable mechanism(s) underlying the anti-inflammatory and therapeutic properties of ethyl caffeate. PMID:16041399

Chiang, Yi-Ming; Lo, Chiu-Ping; Chen, Yi-Ping; Wang, Sheng-Yang; Yang, Ning-Sun; Kuo, Yueh-Hsiung; Shyur, Lie-Fen

2005-01-01

319

Reduced COX-2 Expression in Aged Mice Is Associated With Impaired Fracture Healing  

E-print Network

ABSTRACT: The cellular and molecular events responsible for reduced fracture healing with aging are unknown. Cyclooxygenase 2 (COX-2), the inducible regulator of prostaglandin E2 (PGE2) synthesis, is critical for normal bone repair. A femoral fracture repair model was used in mice at either 7–9 or 52–56 wk of age, and healing was evaluated by imaging, histology, and gene expression studies. Aging was associated with a decreased rate of chondrogenesis, decreased bone formation, reduced callus vascularization, delayed remodeling, and altered expression of genes involved in repair and remodeling. COX-2 expression in young mice peaked at 5 days, coinciding with the transition of mesenchymal progenitors to cartilage and the onset of expression of early cartilage markers. In situ hybridization and immunohistochemistry showed that COX-2 is expressed primarily in early cartilage precursors that co-express col-2. COX-2 expression was reduced by 75 % and 65 % in fractures from aged mice compared with young mice on days 5 and 7, respectively. Local administration of an EP4 agonist to the fracture repair site in aged mice enhanced the rate of chondrogenesis and bone formation to levels observed in young mice, suggesting that the expression of COX-2 during the early inflammatory phase of repair regulates critical subsequent events including chondrogenesis, bone formation, and remodeling. The findings suggest that COX-2/EP4 agonists may compensate for deficient molecular signals that result in the reduced fracture healing associated with aging. J Bone Miner Res 2009;24:251–264. Published online on October 13, 2008; doi: 10.1359/JBMR.081002 Key words: fracture, aging, cyclooxygenases, prostaglandin E2, endochondral ossification

Amish A Naik; Chao Xie; Michael J Zuscik; Paul Kingsley; Edward M Schwarz; Hani Awad; Robert Guldberg; Hicham Drissi; J Edward Puzas; Brendan Boyce; Xinping Zhang; Regis J O’keefe

320

Isomeric acetoxy analogs of celecoxib and their evaluation as cyclooxygenase inhibitors.  

PubMed

A group of celecoxib analogs having a SO(2)NH(2) (9a-f), or SO(2)Me (12a-f), COX-2 pharmacophore at the para-position of the N-1 phenyl ring in conjunction with a C-5 phenyl ring having a variety of substituents (4-, 3-, 2-OAc; 4-Me,2-OAc, 4-Me,3-OAc, 4-F,2-OAc) was synthesized for evaluation as cyclooxygenase (COX) inhibitors of the COX-1/COX-2 isozymes. Within this group of compounds, 1-(4-aminosulfonylphenyl)-3-trifluoromethyl-5-(2-acetoxy-4-fluorophenyl)pyrazole (9f) emerged as the most potent (COX-1 IC(50)=0.7 ?M; COX-2 IC(50)=0.015 ?M) and selective (COX-2 selectivity index=47) inhibitor agent that exhibited good anti-inflammatory activity (ED(50)=42.3mg/kg) which was lower than the reference drug celecoxib (ED(50)=10.8 mg/kg), but greater than ibuprofen (ED(50)=67.4 mg/kg) and aspirin (ED(50)=128.7 mg/kg). Molecular modeling studies for 9f showed that the SO(2)NH(2) group assumes a position within the secondary pocket of the COX-2 active site wherein the SO(2)NH(2) oxygen atom is hydrogen bonded to the H90 residue (2.90Å), the SO(2)NH(2) nitrogen atom forms a hydrogen bond with L352 (N?O=2.80Å), and the acetyl group is positioned in the vicinity of the S530 residue where the acetyl oxygen atom undergoes hydrogen bonding to L531 (2.99Å). PMID:21890358

Abdur Rahim, M; Praveen Rao, P N; Bhardwaj, Atul; Kaur, Jatinder; Huang, Zhangjian; Knaus, Edward E

2011-10-15

321

Development of Potent and Selective Inhibitors of Aldo-Keto Reductase 1C3 (type 5 17?-Hydroxysteroid Dehydrogenase) Based on N-Phenyl-Aminobenzoates and Their Structure Activity Relationships  

PubMed Central

Aldo-keto reductase 1C3 (AKR1C3; type 5 17?-hydroxysteroid dehydrogenase) is overexpressed in castrate resistant prostate cancer (CRPC) and is implicated in the intratumoral biosynthesis of testosterone and 5?-dihydrotestosterone. Selective AKR1C3 inhibitors are required since compounds should not inhibit the highly related AKR1C1 and AKR1C2 isoforms which are involved in the inactivation of 5?-dihydrotestosterone. NSAIDs, N-phenylanthranilates in particular are potent but non-selective AKR1C3 inhibitors. Using flufenamic acid, 2-{[3-(trifluoromethyl)phenyl]amino}benzoic acid as lead compound, five classes of structural analogs were synthesized and evaluated for AKR1C3 inhibitory potency and selectivity. Structure activity relationship (SAR) studies revealed that a meta-carboxylic acid group relative to the amine conferred pronounced AKR1C3 selectivity without loss of potency, while electron withdrawing groups on the phenylamino B-ring were optimal for AKR1C3 inhibition. Lead compounds did not inhibit COX-1 or COX-2 but blocked the AKR1C3 mediated production of testosterone in LNCaP-AKR1C3 cells. These compounds offer promising leads towards new therapeutics for CRPC. PMID:22263837

Adeniji, Adegoke O.; Twenter, Barry M.; Byrns, Michael C.; Jin, Yi; Chen, Mo; Winkler, Jeffrey D.; Penning, Trevor M.

2012-01-01

322

TGF-? Suppresses COX-2 Expression by Tristetraprolin-Mediated RNA Destabilization in A549 Human Lung Cancer Cells  

PubMed Central

Purpose Overexpression of cyclooxygenase 2 (COX-2) is thought to promote survival of transformed cells. Transforming growth factor ? (TGF-?) exerts anti-proliferative effects on a broad range of epithelial cells. In the current study, we investigated whether TGF-? can regulate COX-2 expression in A549 human lung adenocarcinoma cells, which are TGF-?-responsive and overexpress COX-2. Materials and Methods Western blotting, Northern blotting, and mRNA stability assays were performed to demonstrate that COX-2 protein and mRNA expression were suppressed by TGF-?. We also evaluated the effects of tristetraprolin (TTP) on COX-2 mRNA using RNA interference. Results We demonstrated that COX-2 mRNA and protein expression were both significantly suppressed by TGF-?. An actinomycin D chase experiment demonstrated that COX-2 mRNA was more rapidly degraded in the presence of TGF-?, suggesting that TGF-?–induced inhibition of COX-2 expression is achieved via decreased mRNA stability. We also found that TGF-? rapidly and transiently induced the expression of TTP, a well-known mRNA destabilizing factor, before suppression of COX-2 mRNA expression was observed. Using RNA interference, we confirmed that increased TTP levels play a pivotal role in the destabilization of COX-2 mRNA by TGF-?. Furthermore, we showed that Smad3 is essential to TTP-dependent down-regulation of COX-2 expression in response to TGF-?. Conclusion The results of this study show that TGF-? down-regulated COX-2 expression via mRNA destabilization mediated by Smad3/TTP in A549 cells. PMID:25544576

Kang, Soyeong; Min, Ahrum; Im, Seock-Ah; Song, Sang-Hyun; Kim, Sang Gyun; Kim, Hyun-Ah; Kim, Hee-Jun; Oh, Do-Youn; Jong, Hyun-Soon; Kim, Tae-You; Bang, Yung-Jue

2015-01-01

323

Cyclooxygenase2 (COX2), Epidermal Growth Factor Receptor (EGFR), and Her2\\/neu Expression in Ovarian Cancer  

Microsoft Academic Search

Objectives. Cyclooxygenase-2 (COX-2) seems to be involved in critical steps of cancer onset and progression. Abnormalities of epidermal growth factor receptor (EGFR) and Her-2\\/neu have been actively investigated in ovarian cancer and associated with unfavorable clinical outcome. The involvement of COX-2 in ErbB family pathways has been proposed. We investigated by immunohistochemistry the expression of COX-2, EGFR, and Her-2\\/neu in

G. Ferrandina; F. O. Ranelletti; L. Lauriola; F. Fanfani; F. Legge; M. Mottolese; M. R. Nicotra; P. G. Natali; V. H. Zakut; G. Scambia

2002-01-01

324

COX2 activation is associated with Akt phosphorylation and poor survival in ER-negative, HER2-positive breast cancer  

Microsoft Academic Search

BACKGROUND: Inducible cyclooxgenase-2 (COX-2) is commonly overexpressed in breast tumors and is a target for cancer therapy. Here, we studied the association of COX-2 with breast cancer survival and how this association is influenced by tumor estrogen and HER2 receptor status and Akt pathway activation. METHODS: Tumor COX-2, HER2 and estrogen receptor ? (ER) expression and phosphorylation of Akt, BAD,

Sharon A Glynn; Robyn L Prueitt; Lisa A Ridnour; Brenda J Boersma; Tiffany M Dorsey; David A Wink; Julie E Goodman; Harris G Yfantis; Dong H Lee; Stefan Ambs

2010-01-01

325

Effect of NOS Inhibitor on Cytokine and COX2 Expression in Rat Pulpitis  

Microsoft Academic Search

Various kinds of chemical mediators are synthesized in the course of pulpitis; thus, control of their production would assist in inducing a reduction in pulpal inflammation. We hypothesized that nitric oxide (NO) would be an important mediator of pulpal inflammation. Pulpal inflammation was induced by the application of LPS in rat incisor pulp, and inducible nitric oxide synthase (iNOS) expression

N. Kawashima; H. Nakano-Kawanishi; N. Suzuki; M. Takagi; H. Suda

2005-01-01

326

Synthesis and Structure-Activity Relationship Studies of Urea-Containing Pyrazoles as Dual Inhibitors of Cyclooxygenase-2 and Soluble Epoxide Hydrolase  

PubMed Central

A series of dual inhibitors containing a 1,5-diarylpyrazole and a urea were designed, synthesized, and evaluated as novel COX-2/sEH dual inhibitors in vitro using recombinant enzyme assays and in vivo using a lipopolysaccharide (LPS) induced model of pain in rats. The best inhibition potencies and selectivity for sEH and COX-2 over COX-1 were obtained with compounds (21b, 21i and 21j) in which both the 1,5-diaryl-pyrazole group and the urea group are linked with a three-methylene group. Compound 21i showed the best pharmacokinetic profiles in both mice and rats (higher AUC and longer half-life). Following subcutaneous administration at 10 mg/kg, compound 21i exhibited anti-allodynic activity that is more effective than the same dose of either a COX-2 inhibitor (celecoxib) or a sEH inhibitor (t-AUCB) alone, as well as co-administration of both inhibitors. Thus, these novel dual inhibitors exhibited enhanced in vivo anti-allodynic activity in a nociceptive behavioral assay. PMID:21434686

Hwang, Sung Hee; Wagner, Karen M.; Morisseau, Christophe; Liu, Jun-Yan; Dong, Hua; Wecksler, Aaron T.; Hammock, Bruce D.

2012-01-01

327

Synthesis and structure-activity relationship studies of urea-containing pyrazoles as dual inhibitors of cyclooxygenase-2 and soluble epoxide hydrolase.  

PubMed

A series of dual inhibitors containing a 1,5-diarylpyrazole and a urea were designed, synthesized, and evaluated as novel COX-2/sEH dual inhibitors in vitro using recombinant enzyme assays and in vivo using a lipopolysaccharide (LPS) induced model of pain in rats. The best inhibition potencies and selectivity for sEH and COX-2 over COX-1 were obtained with compounds (21b, 21i, and 21j) in which both the 1,5-diaryl-pyrazole group and the urea group are linked with a three-methylene group. Compound 21i showed the best pharmacokinetic profiles in both mice and rats (higher AUC and longer half-life). Following subcutaneous administration at 10 mg/kg, compound 21i exhibited antiallodynic activity that is more effective than the same dose of either a COX-2 inhibitor (celecoxib) or a sEH inhibitor (t-AUCB) alone, as well as coadministration of both inhibitors. Thus, these novel dual inhibitors exhibited enhanced in vivo antiallodynic activity in a nociceptive behavioral assay. PMID:21434686

Hwang, Sung Hee; Wagner, Karen M; Morisseau, Christophe; Liu, Jun-Yan; Dong, Hua; Wecksler, Aaron T; Hammock, Bruce D

2011-04-28

328

Synthesis and SAR study of imidazoquinolines as a novel structural class of microsomal prostaglandin E? synthase-1 inhibitors.  

PubMed

The imidazoquinoline derivative 1 was found as a novel mPGES-1 inhibitor. Optimization of 1 led to the identification of the 2-chlorophenyl group at the C(2)-position and the quinolone structure at the C(4)-position. Compound 33, the most potent synthesized compound, showed excellent mPGES-1 inhibition (IC(50)=9.1nM) with high selectivity (>1000-fold) over both COX-1 and COX-2. PMID:22137787

Shiro, Tomoya; Takahashi, Hirotada; Kakiguchi, Keisuke; Inoue, Yoshifumi; Masuda, Keiki; Nagata, Hidetaka; Tobe, Masanori

2012-01-01

329

Elevated COX2 expression and PGE2 production by downregulation of RXR? in senescent macrophages  

SciTech Connect

Highlights: •Downregulation of RXR? in senescent macrophage. •RXR? suppresses NF-?B activity and COX2 expression. •Increased PGE2 production due to downregulation of RXR?. -- Abstract: Increased systemic level of inflammatory cytokines leads to numerous age-related diseases. In senescent macrophages, elevated prostaglandin E2 (PGE2) production contributes to the suppression of T cell function with aging, which increases the susceptibility to infections. However, the regulation of these inflammatory cytokines and PGE2 with aging still remains unclear. We have verified that cyclooxygenase (COX)-2 expression and PGE2 production are higher in LPS-stimulated macrophages from old mice than that from young mice. Downregulation of RXR?, a nuclear receptor that can suppress NF-?B activity, mediates the elevation of COX2 expression and PGE2 production in senescent macrophages. We also have found less induction of ABCA1 and ABCG1 by RXR? agonist in senescent macrophages, which partially accounts for high risk of atherosclerosis in aged population. Systemic treatment with RXR? antagonist HX531 in young mice increases COX2, TNF-?, and IL-6 expression in splenocytes. Our study not only has outlined a mechanism of elevated NF-?B activity and PGE2 production in senescent macrophages, but also provides RXR? as a potential therapeutic target for treating the age-related diseases.

Chen, Huimin, E-mail: huiminchen.jq@gmail.com [Department of Geratology, Liaoning Jinqiu Hospital, Shenyang 110015 (China)] [Department of Geratology, Liaoning Jinqiu Hospital, Shenyang 110015 (China); Ma, Feng [Institute of Immunology, Zhejiang University of Medicine, Hangzhou 310058 (China)] [Institute of Immunology, Zhejiang University of Medicine, Hangzhou 310058 (China); Hu, Xiaona; Jin, Ting; Xiong, Chuhui [Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001 (China)] [Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001 (China); Teng, Xiaochun, E-mail: tengxiaochun@126.com [Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001 (China)] [Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001 (China)

2013-10-11

330

COX2 is necessary for venous ligation-mediated bone adaptation in mice  

Microsoft Academic Search

In osteoblasts, cyclooxygenase 2 (COX-2) is the major isozyme responsible for production of prostaglandins. Prostaglandins are local mediators of bone resorption and formation and are known to be involved in bone's adaptive response to fluid shear stress (FSS). We have previously described a model of trabecular bone loss in hindlimb-suspended mice and rats and demonstrated partial protection from osteopenia by

H. Y. Stevens; D. R. Meays; J. Yeh; L. M. Bjursten; J. A. Frangos

2006-01-01

331

ZN2+ INDUCES COX-2 EXPRESSION THROUGH DOWNREGULATION OF LIPID PHOSPHATASE PTEN  

EPA Science Inventory

Zn2+ Induces COX-2 Expression through Downregulation of Lipid Phosphatase PTEN Weidong Wu*, James M. Samet, Philip A. Bromberg*?, Young E. Whang?, and Lee M. Graves* ? *CEMALB, ?Department of Medicine, and ?Department of Pharmacology, UNC-Chapel Hill, NC27599; Human Studie...

332

Effects of Cyclooxygenase2 Selective and Nitric Oxide-Releasing Nonsteroidal Antiinflammatory Drugs on Mucosal Ulcerogenic and Healing Responses of the Stomach  

Microsoft Academic Search

Effects of selective cyclooxygenase-2 (COX-2)inhibitors (NS-398) and nitric oxide (NO)-releasingaspirin (NO-ASA) on gastric ulcerogenic and healingresponses were examined in comparison with nonselective COX inhibitors such as indomethacin and aspirin(ASA). Hypothermic stress (28-30°C, 4 hr) inducedgastric lesions in anesthetized rats with an increase ofacid secretion. The lesions induced by hypothermic stress were markedly worsened by subcutaneousadministration of both indomethacin and ASA

Hideki Ukawa; Hisashi Yamakuni; Shinichi Kato; Koji Takeuchi

1998-01-01

333

Discovery of triazines as selective PDE4B versus PDE4D inhibitors.  

PubMed

In this study we report a series of triazine derivatives that are potent inhibitors of PDE4B. We also provide a series of structure activity relationships that demonstrate the triazine core can be used to generate subtype selective inhibitors of PDE4B versus PDE4D. A high resolution co-crystal structure shows that the inhibitors interact with a C-terminal regulatory helix (CR3) locking the enzyme in an inactive 'closed' conformation. The results show that the compounds interact with both catalytic domain and CR3 residues. This provides the first structure-based approach to engineer PDE4B-selective inhibitors. PMID:24998378

Hagen, Timothy J; Mo, Xuesheng; Burgin, Alex B; Fox, David; Zhang, Zheng; Gurney, Mark E

2014-08-15

334

Aspects of corrosion inhibitor selection at elevated temperatures  

SciTech Connect

Corrosion inhibitors were evaluated in a flow loop apparatus, for a subsea production flowline application in a major gas condensate project. The design temperature for the prediction was 115 C, with a considerable CO{sub 2} presence. Acceptable corrosion inhibitors were identified in this examination. However, the evaluation demonstrated that the presently available green inhibitors were not suitable. The corrosion performance was strongly dependent on temperature, especially above around 90 C. Most inhibitors performed well (less than 0.025 mm/y or 1 mpy) in the static environment, but exhibited poorer performance in the flowing (4 m/s) condition. Elevated temperature performance was associated with separation of the hydrocarbon and aqueous phases. This study was influenced by the general lack of corrosion inhibitor partitioning data available in the industry.

Kolts, J.; Jooaten, M.W.; Humble, P.G. [Conoco, Inc., Ponca City, OK (United States); Clapham, J. [Britannia Project, London (United Kingdom)

1998-12-31

335

Selection of corrosion inhibitors to control microbiologically influenced corrosion  

SciTech Connect

Microbiologically Influenced Corrosion (MIC) is a serious problem. The establishment of a biofilm on a metal surface plays a critical role in MIC. Quaternary amines have been reported to inhibit the bacterial adhesion to the metal surface. However, most of the quaternary amines are quite toxic. In light of growing concerns of environmental impact and safety, a series of experiments was conducted to evaluate various corrosion inhibitors for their inhibition capability of bacterial adhesion as well as bacterial kill. The results indicate that some inhibitors are capable of inhibiting biofilm formation on mild steel coupons. In addition, these inhibitors have biocidal properties. Initial toxicity studies suggest that some of these inhibitors are less toxic than most industrial biocides. This paper discusses the cost-effectiveness of use of these inhibitors in some systems.

Prasad, R. [Champion Technologies, Inc., Fresno, TX (United States)

1998-12-31

336

Stromal COX-2 signaling activated by deoxycholic acid mediates proliferation and invasiveness of colorectal epithelial cancer cells  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Human colonic cancer associated fibroblasts are major sources of COX-2 and PGE{sub 2}. Black-Right-Pointing-Pointer The fibroblasts interact with human colonic epithelial cancer cells. Black-Right-Pointing-Pointer Activation of COX-2 signaling in the fibroblasts affects behavior of the epithelia. Black-Right-Pointing-Pointer Protein Kinase C controls the activation of COX-2 signaling. -- Abstract: COX-2 is a major regulator implicated in colonic cancer. However, how COX-2 signaling affects colonic carcinogenesis at cellular level is not clear. In this article, we investigated whether activation of COX-2 signaling by deoxycholic acid (DCA) in primary human normal and cancer associated fibroblasts play a significant role in regulation of proliferation and invasiveness of colonic epithelial cancer cells. Our results demonstrated while COX-2 signaling can be activated by DCA in both normal and cancer associated fibroblasts, the level of activation of COX-2 signaling is significantly greater in cancer associated fibroblasts than that in normal fibroblasts. In addition, we discovered that the proliferative and invasive potential of colonic epithelial cancer cells were much greater when the cells were co-cultured with cancer associated fibroblasts pre-treated with DCA than with normal fibroblasts pre-treated with DCA. Moreover, COX-2 siRNA attenuated the proliferative and invasive effect of both normal and cancer associate fibroblasts pre-treated with DCA on the colonic cancer cells. Further studies indicated that the activation of COX-2 signaling by DCA is through protein kinase C signaling. We speculate that activation of COX-2 signaling especially in cancer associated fibroblasts promotes progression of colonic cancer.

Zhu, Yingting, E-mail: yitizhu@yahoo.com [Arizona Cancer Center, The University of Arizona, Tucson, AZ 85724 (United States) [Arizona Cancer Center, The University of Arizona, Tucson, AZ 85724 (United States); Tissue Tech Inc., Miami, FL 33173 (United States); Zhu, Min; Lance, Peter [Arizona Cancer Center, The University of Arizona, Tucson, AZ 85724 (United States)] [Arizona Cancer Center, The University of Arizona, Tucson, AZ 85724 (United States)

2012-08-31

337

Specific trans-acting proteins interact with auxiliary RNA polyadenylation elements in the COX-2 3?-UTR  

PubMed Central

Two cyclooxygenase (COX) enzymes, COX-1 and COX-2, are present in human cells. While COX-1 is constitutively expressed, COX-2 is inducible and up-regulated in response to many signals. Since increased transcriptional activity accounts for only part of COX-2 up-regulation, we chose to explore other RNA processing mechanisms in the regulation of this gene. Previously, we showed that COX-2 is regulated by alternative polyadenylation, and that the COX-2 proximal polyadenylation signal contains auxiliary upstream sequence elements (USEs) that are very important in efficient polyadenylation. To explore trans-acting protein factors interacting with these cis-acting RNA elements, we performed pull-down assays with HeLa nuclear extract and biotinylated RNA oligonucleotides representing COX-2 USEs. We identified PSF, p54nrb, PTB, and U1A as proteins specifically bound to the COX-2 USEs. We further explored their participation in polyadenylation using MS2 phage coat protein-MS2 RNA binding site tethering assays, and found that tethering any of these four proteins to the COX-2 USE mutant RNA can compensate for these cis-acting elements. Finally, we suggest that these proteins (p54nrb, PTB, PSF, and U1A) may interact as a complex since immunoprecipitations of the transfected MS2 fusion proteins coprecipitate the other proteins. PMID:17507659

Hall-Pogar, Tyra; Liang, Songchun; Hague, Lisa K.; Lutz, Carol S.

2007-01-01

338

Relative contribution of acetylated cyclooxygenase (COX)-2 and 5-lipooxygenase (LOX) in regulating gastric mucosal integrity and adaptation to aspirin  

Microsoft Academic Search

In addition to inhibiting formation of prothrombotic eicosanoids, aspirin causes the acetylation of cyclooxygenase (COX)-2. The acetylated COX-2 remains active, and upon cell activation, initiates the generation of 15R-HETE, a lipid substrate for 5-lipoxygenase (LOX) leading to the formation of 15-epi-LXA4 (also termed \\

Stefano Fiorucci; Eleonora Distrutti; Octavio Menezes de Lima; Mario Romano; Andrea Mencarelli; Miriam Barbanti; Ernesto Palazzini; Antonio Morelli; John L. Wallace

2003-01-01

339

Biochemical And Structural Evaluation of Highly Selective 2-Arylbenzoxazole-Based Transthyretin Amyloidogenesis Inhibitors  

SciTech Connect

To develop potent transthyretin (TTR) amyloidogenesis inhibitors that also display high binding selectivity in blood, it proves useful to systematically optimize each of the three substructural elements that comprise a typical inhibitor: the two aryl rings and the linker joining them. In the first study, described herein, structural modifications to one aryl ring were evaluated by screening a library of 2-arylbenzoxazoles bearing thyroid hormone-like aryl substituents on the 2-aryl ring. Several potent and highly selective amyloidogenesis inhibitors were identified that exhibit minimal thyroid hormone nuclear receptor and COX-1 binding. High resolution crystal structures (1.3-1.5 A) of three inhibitors (2f, 4f, and 4d) in complex with TTR were obtained to characterize their binding orientation. Collectively, the results demonstrate that thyroid hormone-like substitution patterns on one aryl ring lead to potent and highly selective TTR amyloidogenesis inhibitors that lack undesirable thyroid hormone receptor or COX-1 binding.

Johnson, S.M.; Connelly, S.; Wilson, I.A.; Kelly, J.W.

2009-05-18

340

Adamantyl triazoles as selective inhibitors of 11?-hydroxysteroid dehydrogenase type 1  

Microsoft Academic Search

Adamantyl triazoles were identified as selective inhibitors of 11?-hydroxysteroid dehydrogenase type 1 (11?-HSD1). They are active both in in vitro and in in vivo pharmacodynamic models. The synthesis and structure–activity relationships of these inhibitors are presented.

Steven Olson; Susan D. Aster; Kai Brown; Linda Carbin; Donald W. Graham; Anne Hermanowski-Vosatka; Cheryl B. LeGrand; Steven S. Mundt; Michael A. Robbins; James M. Schaeffer; Llnon H. Slossberg; Michael J. Szymonifka; Rolf Thieringer; Samuel D. Wright; James M. Balkovec

2005-01-01

341

Pyrazolobenzotriazinone derivatives as COX inhibitors: synthesis, biological activity, and molecular-modeling studies.  

PubMed

Pyrazolylbenzotriazinones are endowed with a structural analogy with the COX-2 selective inhibitor celecoxib. Considering that our research group has long been interested in the 3-pyrazolyl-substituted benzotriazinones as anti-inflammatory agents, six new pyrazolylbenzotriazinone derivatives 16a-c and 18a-c have been prepared by reacting the opportune ethyl 5-(2-aminobenzamido)-1-(pyridin-2-yl)-1H-pyrazole-4-carboxylate or 5-(2-aminobenzamido)-1-(pyridin-2-yl)-1H-pyrazole-4-carboxyic acid with sodium nitrite in glacial acetic acid. The biological studies revealed a good pharmacological profile for some pyrazolylbenzotriazinones and, in the case of the ethyl 5-(4-oxo-1,2,3-benzotriazin-3(4H)-yl)-1-pyridin-2-yl-1H-pyrazole-4-carboxylate, a good COX-1/COX-2 selectivity. Molecular modeling studies confirmed the obtained biological results. PMID:21110338

Raffa, Demetrio; Migliara, Onofrio; Maggio, Benedetta; Plescia, Fabiana; Cascioferro, Stella; Cusimano, Maria Grazia; Tringali, Giuseppe; Cannizzaro, Carla; Plescia, Fulvio

2010-11-01

342

Relationship between 12/15-lipoxygenase and COX-2 in mesangial cells: potential role in diabetic nephropathy.  

PubMed

The 12/15-lipoxygenase (12/15-LO) and cyclooxygenase-2 (COX-2) pathways of arachidonate metabolism have been implicated in the pathogenesis of diabetic nephropathy (DN). In this study, we evaluated whether there is an interplay between 12/15-LO and COX-2 pathways in mesangial cells (MC). We utilized MC, microdissected glomeruli and renal cortical tissues. Transfections with cDNAs or short hairpin RNAs (shRNAs) were performed to overexpress or knockdown 12/15-LO and COX-2, respectively. Reverse transcription-polymerase chain reactions and Western blotting were used for evaluating mRNA and protein expression, respectively. We observed that the expression of both 12/15-LO and COX-2 were increased in high glucose stimulated rat MC relative to normal glucose, and also in cortical tissues from diabetic db/db and streptozotocin-injected mice relative to corresponding control mice. Treatment of rat MC with the 12/15-LO product, 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE), significantly increased COX-2 expression as well as levels of the COX-2 product, prostaglandin E(2) (PGE(2)). Interestingly, treatment of rat MC with PGE(2) led to a reciprocal increase in 12/15-LO expression as well as levels of 12(S)-HETE. The 12/15-LO shRNA could significantly attenuate COX-2 protein expression and vice versa. Furthermore, COX-2 expression levels were lower in MC and glomeruli from 12/15-LO knockout mice relative to control. Conversely, mouse MC stably overexpressing 12/15-LO had greater levels of COX-2 expression relative to mock-transfected cells. These new results indicate for the first time that 12/15-LO and COX-2 pathways can cross-talk and activate each other in MC. These novel interactions may amplify their effects on the progression of DN. PMID:16514433

Xu, Z-G; Li, S-L; Lanting, L; Kim, Y-S; Shanmugam, N; Reddy, M A; Natarajan, R

2006-02-01

343

COX-2 expression in papillary thyroid carcinoma (PTC) in cytological material obtained by fine needle aspiration biopsy (FNAB)  

PubMed Central

Background COX-2 is an enzyme isoform that catalyses the formation of prostanoids from arachidonic acid. An increased COX-2 gene expression is believed to participate in carcinogenesis. Recent studies have shown that COX-2 up-regulation is associated with the development of numerous neoplasms, including skin, colorectal, breast, lung, stomach, pancreas and liver cancers. COX-2 products stimulate endothelial cell proliferation and their overexpression has been demonstrated to be involved in the mechanism of decreased resistance to apoptosis. Suppressed angiogenesis was found in experimental animal studies as a consequence of null mutation of COX-2 gene in mice. Despite the role of COX-2 expression remains a subject of numerous studies, its participation in carcinogenesis or the thyroid cancer progression remains unclear. Methods Twenty three (23) patients with cytological diagnosis of PTC were evaluated. After FNAB examination, the needle was washed out with a lysis buffer and the obtained material was used for COX-2 expression estimation. Total RNA was isolated (RNeasy Micro Kit), and RT reactions were performed. ?-actin was used as endogenous control. Relative COX-2 expression was assessed in real-time PCR reactions by an ABI PRISM 7500 Sequence Detection System, using the ??CT method. Results COX-2 gene expression was higher in patients with PTC, when compared to specimens from patients with non-toxic nodular goitre (NTG). Conclusions The preliminary results may indicate COX-2 role in thyroid cancer pathogenesis, however the observed variability in results among particular subjects requires additional clinical data and tumor progression analysis. PMID:21214962

2011-01-01

344

The identification of beta-hydroxy carboxylic acids as selective MMP-12 inhibitors.  

PubMed

A new class of selective MMP-12 inhibitors have been identified via high throughput screening. Crystallization with MMP-12 confirmed the mode of binding and allowed initial optimization to be carried out using classical structure based