N-(3-Arylaminopyridin-4-yl)alkanesulfonamides as pyridine analogs of nimesulide: cyclooxygenases inhibition, anti-inflammatory studies and insight on metabolism.

Nimesulide, a COX-2 preferential inhibitor with a favorable gastric and cardiovascular safety profile, was responsible for some cases of acute liver failure attributed to the nitrobenzene ring. A series of analogs of nimesulide resulting from isosteric replacement of the nitrobenzene ring by the pyridine nucleus, was synthesized and their ability to inhibit both cyclooxygenases (COXs) isoforms was evaluated in vitro using a human whole blood model. Compounds 19c, 23b and 23c displayed an important inhibitory activity associated to a COX-2/COX-1 selectivity ratio similar to or higher than that of celecoxib.

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

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.

Structure-based pharmacophore of COX-2 selective inhibitors and identification of original lead compounds from 3D database searching method.

A four-point pharmacophore of COX-2 selective inhibitors was derived from a training set of 16 compounds, using the Catalyst program. It consists of a H bond acceptor, two hydrophobic groups and an aromatic ring, in accordance with SAR data of the compounds and with topology of the COX-2 active site. This hypothesis, combined with exclusion volume spheres representing important residues of the COX-2 binding site, was used to virtually screen the Maybridge database.

Evaluation of original dual thromboxane A2 modulators as antiangiogenic agents.

Angiogenesis is a promising target for the therapy of several diseases including cancer. This study was undertaken to characterize the antiangiogenic properties of a series of original dual thromboxane A(2) (TXA(2)) inhibitors derived from torasemide, a marketed loop diuretic with TXA(2) antagonistic properties, by evaluating their effects on human endothelial cell migration, adhesion, and viability in vitro, as well as in the ex vivo rat aortic ring assay. All drugs tested exhibited a marked affinity toward human platelet TXA(2) receptor, significantly prevented platelet aggregation induced by U-46,619, a stable TXA(2) receptor agonist, and inhibited platelet TXA(2) synthase without affecting cyclooxygenase (COX)-1 or COX-2 enzymatic activities.

The use of nimesulide and its analogues in cancer chemoprevention.

Non-steroidal anti-inflammatory drugs (NSAIDs), which are known to be cyclooxygenase (COX) inhibitors, have been reported to exert anti-proliferative and pro-apoptotic effects on a variety of cancer cells. Since the COX-2 isoform was found to be overexpressed in a many human cancers, a particular attention was paid on the possible use of selective COX-2 inhibitors in cancer chemoprevention. The present review focuses on the state of the art in cancer research developed with COX-2 preferential/selective inhibitors belonging to the family of N-arylmethanesulfonamides, in particular nimesulide and NS-398.

From the design to the clinical application of thromboxane modulators.

Arachidonic acid (AA) metabolites are key mediators involved in the pathogenesis of numerous cardiovascular, pulmonary, inflammatory, and thromboembolic diseases. One of these bioactive metabolites of particular importance is thromboxane A(2) (TXA(2)). It is produced by the action of thromboxane synthase on the prostaglandin endoperoxide H(2) (PGH(2)) which results from the enzymatic transformation of AA by the cyclooxygenases.

Activation of the thromboxane A2 pathway in human prostate cancer correlates with tumor Gleason score and pathologic stage.

Objective: We investigated the potential involvement of the thromboxane A(2) (TXA(2)) pathway in human prostate cancer (PCa).

Methods: Expression of cyclooxygenase-2 (COX-2), TXA(2) synthase (TXS), and TXA(2) receptors (TPRs), the main actors of the TXA(2) pathway, was analyzed on serial tissue sections from 46 human PCa specimens.

Results: The expression levels of COX-2, TXS, and TPRs were significantly higher in malignant than in corresponding nontumoral prostatic epithelial cells.

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

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.

Synthesis, molecular modelling and enzymatic evaluation of (+/-)3,5-diphenyl-2-thioxoimidazolidin-4-ones as new potential cyclooxygenase inhibitors.

A series of substituted (+/-)3,5-diphenyl-2-thioxoimidazolin-4-ones was synthesized in order to design new type-2 cyclooxygenase (COX-2) inhibitors. This study has led to molecules which completely inhibit human recombinant COX-2 at 50 microM. Molecular modelling highlighted drug interactions with the active site of both cyclooxygenases and suggested modifications to enhance the selectivity of the compounds.

Carbonic anhydrase inhibitors: synthesis and inhibition of cytosolic/membrane-associated carbonic anhydrase isozymes I, II, and IX with sulfonamides incorporating hydrazino moieties.

Targeting proteins overexpressed in hypoxic tumors is as an important means of controlling cancer disease. One such protein is the carbonic anhydrase (CA) isoenzyme IX, which in some types of tumors is overexpressed 150-200-fold. We report here a series of sulfonamide derivatives, prepared from 2-carbohydrazido- and 4-carbohydrazido-benzenesulfonamides, which were further derivatized by reaction with aryl isocyanates or arylsulfonyl isocyanates.

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

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.

Effects of COX-2 inhibitors on ROS produced by Chlamydia pneumoniae-primed human promonocytic cells (THP-1).

Chronic inflammation through foam cells and macrophages is important in atherosclerosis development, and can be considered as therapeutic targets. Cyclooxygenase and NADPH-oxidase were expressed within atherosclerotic lesions. Reactive oxygen species produced by NADPH oxidase were found to trigger the cyclooxygenase-2 expression.

Progress in the field of GPIIb/IIIa antagonists.

Platelet aggregation plays an important role in pathological situations such as myocardial infarction, unstable angina, peripheral artery disease, and stroke. Thus, pharmacological agents that specifically inhibit platelet aggregation are of great interest in the treatment and prevention of these cardiovascular diseases. Since binding of activated glycoprotein IIb/IIIa complex, a platelet surface integrin, to fibrinogen is the final step leading to platelet aggregation regardless of the initial stimulus, many researches have focused on the development of drugs that could antagonize this integrin.

Modulation of the arachidonic cascade with omega3 fatty acids or analogues: potential therapeutic benefits.

Increasing interest in the role of omega3 fatty acids has arisen in these latest years since evidence of their implication in the cardioprotective fish based diet of the Inuit has been demonstrated. Furthermore, several in vitro, in vivo and epidemiological studies support the benefit of this fatty acids intake in various pathological states such as in the cardiovascular, cancer, inflammation, psychiatric, paediatric, pulmonary, dermatological and ophthalmologic fields. This review will focus on metabolism and pharmacological implication of omega3 fatty acids intake as well as its interest in the prevention or treatment of the above-mentioned pathologies.

New developments on thromboxane modulators.

Thromboxane A(2) (TXA(2)) is a labile product formed from arachidonic acid by cyclooxygenase. The pathogenesis of numerous cardiovascular, pulmonary, and thromboembolic diseases can be related to this metabolite. Therefore, TXA(2) modulators have been developed for 20 years.

Recent development in the field of dual COX / 5-LOX inhibitors.

Cyclooxygenases and lipoxygenase are key enzymes in the arachidonic acid metabolism. Dual inhibitors are drugs able to block both the COX and the 5-LOX metabolic pathways. Compared to COX or LOX pathways single inhibitors, dual inhibitors present at least two major advantages.

First and second generations of COX-2 selective inhibitors.

The identification and characterization of the inducible form of cyclooxygenases (COX-2) stimulated the investigations to develop efficient, non-steroidal anti-inflammatory drugs (NSAIDs) with reduced side effects (essentially gastro-intestinal toxicity) compared to classical NSAIDs. This review focuses on the chemical and pharmacological properties (pre-clinical data) of marketed COX-2 inhibitors.

Carbonic anhydrase inhibitors: synthesis and topical intraocular pressure lowering effects of fluorine-containing inhibitors devoid of enhanced reactivity.

Polyfluorinated carbonic anhydrase inhibitors (CAIs) show very good inhibitory properties against carbonic anhydrase (CA) and excellent in vivo antiglaucoma properties after topical administration in rabbits. Still, the pentafluorinated compounds reported previously by this group (Scozzafava et al. J.

New developments on thromboxane and prostacyclin modulators part II: prostacyclin modulators.

Prostacyclin (PGI(2)) is a potent endogenous inhibitor of platelet function and possesses a strong vasodilator effect. Furthermore, prostacyclin is currently presented as the physiologic antagonist of thromboxane A(2)(TXA(2)), which exhibits pro-aggregatory and vasoconstrictor properties. So, the balance between PGI(2) and TXA(2) production is crucial for the cardiovascular system.

New developments on thromboxane and prostacyclin modulators part I: thromboxane modulators.

The pathogenesis of numerous cardiovascular, pulmonary, inflammatory, and thromboembolic diseases can be related to arachidonic acid (AA) metabolites. One of these bioactive metabolites of particular importance is thromboxane A(2) (TXA(2)). It is produced by the action of thromboxane synthase on the prostaglandin endoperoxide H(2)(PGH(2)), which results from the enzymatic degradation of AA by the cyclooxygenases.

Pharmacological characterization of N-tert-butyl-N'-[2-(4'-methylphenylamino)-5-nitrobenzenesulfonyl]urea (BM-573), a novel thromboxane A2 receptor antagonist and thromboxane synthase inhibitor in a rat model of arterial thrombosis and its effects on bleeding time.

The present study was undertaken to characterize the antiplatelet and antithrombotic effects of BM-573 [N-tert-butyl-N'-[2-(4'-methylphenylamino)-5-nitrobenzenesulfonyl]urea], an original combined thromboxane receptor antagonist and thromboxane synthase inhibitor in rats, and to determine its effects on mice bleeding time. Intraperitoneal injection of a single dose of 5 mg/kg BM-573 to rats inhibited U-46619 (9,11-dideoxy-9,11-methanoepoxy-prostaglandin F(2))-induced washed platelet aggregation 30 min and 1, 2, and 4 h after drug administration with a maximum antiplatelet effect observed after 1 and 2 h. In a rat model of thrombosis induced by ferric chloride application on the abdominal aorta, BM-573 significantly reduced the thrombus weight by 92.

Thromboxane A2 inhibition: therapeutic potential in bronchial asthma.

Bronchial asthma is a disease defined by reversible airway obstruction, bronchial hyperresponsiveness and inflammation. In addition to histamine and acetylcholine, recent studies have emphasized the role of arachidonic acid metabolites (leukotrienes, prostaglandins and thromboxane A(2)) in the pathogenesis of asthma. Among these mediators, thromboxane A(2) (TXA(2)) has attracted attention as an important mediator in the pathophysiology of asthma because of its potent bronchoconstrictive activity.

Spectral and crystallographic study of pyridinic analogues of nimesulide: determination of the active form of methanesulfonamides as COX-2 selective inhibitors.

Compound 7, N-(3-phenoxy-4-pyridinyl)trifluoromethanesulfonamide, showed in vitro (whole blood assay) a strong inhibitory activity on the two cyclooxygenase (COX) enzymes (IC(50)(COX-1) = 2.2 microM and IC(50)(COX-2) = 0.4 microM), being more active but less COX-2-selective than nimesulide.

New trends in dual 5-LOX/COX inhibition.

Dual inhibitors are drugs able to block both the COX and the 5-LOX metabolic pathways. The interest of developing such compounds is supported by a large number of pharmacological studies. Compared to COX or LOX pathways single inhibitors, dual inhibitors present at least two major advantages.