Structural Basis of Enantioselective Inhibition of Cyclooxygenase-1 by S-α-Substituted Indomethacin Ethanolamides

The modification of the nonselective nonsteroidal anti-inflammatory drug, indomethacin, by amidation presents a promising strategy for designing novel cyclooxygenase (COX)-2-selective inhibitors. A series of α-substituted indomethacin ethanolamides, which exist as R/S-enantiomeric pairs, provides a means to study the impact of stereochemistry on COX inhibition. Comparative studies revealed that the R- and S-enantiomers of the α-substituted analogs inhibit COX-2 with almost equal efficacy, whereas COX-1 is selectively inhibited by the S-enantiomers. Mutagenesis studies have not been able to identify residues that manifest the enantioselectivity in COX-1. In an effort to understand the structural impact of chirality on COX-1 selectivity, the crystal structures of ovine COX-1 in complexes with an enantiomeric pair of these indomethacin ethanolamides were determined at resolutions between 2.75 and 2.85Å. These structures reveal unique, enantiomer-selective interactions within the COX-1 side pocket region that stabilize drug binding and account for the chiral selectivity observed with the (S)-α-substituted indomethacin ethanolamides. Kinetic analysis of binding demonstrates that both inhibitors bind quickly utilizing a two-step mechanism. However, the second binding step is readily reversible for the R-enantiomer, whereas for the S-enantiomer, it is not. These studies establish for the first time the structural and kinetic basis of high affinity binding of a neutral inhibitor to COX-1 and demonstrate that the side pocket of COX-1, previously thought to be sterically inaccessible, can serve as a binding pocket for inhibitor association.

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Comparative Analysis of Pharmacologic and/or Genetic Disruption of Cyclooxygenase-1 and Cyclooxygenase-2 Function in Female Reproduction in Mice*

Endocrinology ◽

10.1210/endo.142.7.8307 ◽

2001 ◽

Vol 142 (7) ◽

pp. 3198-3206 ◽

Cited By ~ 40

Author(s):

Jeff Reese ◽

Xuemei Zhao ◽

Wen-Ge Ma ◽

Naoko Brown ◽

Timothy J. Maziasz ◽

...

Keyword(s):

Early Pregnancy ◽

Synergistic Effects ◽

Female Reproduction ◽

Cox Inhibitors ◽

Cyclooxygenase 1 ◽

Simultaneous Inhibition ◽

Cox 2 ◽

Alternative Sources ◽

First Time ◽

Cox 1

Abstract Cyclooxygenase (COX)-derived prostaglandins are critical in female reproduction. Gene targeting studies show that ovulation, fertilization, implantation, and decidualization are defective in COX-2 deficient mice. We used genetic and pharmacologic approaches to perturb COX function and examine the differential and synergistic effects of inhibition of COX-1, COX-2, or of both isoforms on reproductive outcomes during early pregnancy in mice. The results demonstrate that simultaneous inhibition of COX-1 and COX-2 produces more severe effects on early pregnancy events than inhibition of either isoform alone. The effects of pharmacological inhibition of COX-2 on female reproductive functions were less severe than the null mutation of the COX-2 gene. A combined approach showed that COX-2 inhibition in COX-1−/− mice induced complete reproductive failure, suggesting a lack of alternative sources of prostaglandin synthesis. This investigation raises caution regarding the indiscriminate use of COX inhibitors and shows for the first time the distinct and overlapping pathways of the cyclooxygenase systems in female reproduction.

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The Quercetin and Quercetin Derivatives Interaction With Cyclooxygenase-1 and Cyclooxygenase-2

10.1101/2020.12.05.413088 ◽

2020 ◽

Author(s):

A.E. Manukyan ◽

A.A. Hovhannisyan

Keyword(s):

Biological Activities ◽

Three Dimensional ◽

Docking Analysis ◽

Quercetin Derivatives ◽

Cyclooxygenase 1 ◽

Activity Modeling ◽

Pubchem Database ◽

Cox 2 ◽

First Time ◽

Cox 1

ABSTRACTThe cyclooxygenase (COX) enzymes are tumor markers, the inhibition of which can be used in the prevention and therapy of carcinogenesis. It was found that COX-1 and COX-2 are considered as targets for tumor inhibition. In anticancer therapy, plant compounds are considered that can inhibit their activity. Modeling of the COX-1 and COX-2 enzymes was carried out on the basis of molecular models of three-dimensional structures from the PDB database [PDB ID: 3KK6, 5f19] RCSB. For docking analysis, 3D ligand models were created using MarvinSketch based on the PubChem database [CID: 5280343, 5281654]. In silico experiments, for the first time, revealed the possible interaction and inhibition of COX-1 and COX-2 by quercetin and quercetin derivatives. Aspirin and Celecoxib [CID: 2244, 2662] were taken to compare the results. Possible biological activities and possible side effects of the ligands have been identified. It is noteworthy that Celecoxib is not active on the studied cell lines, while quercetin and quercetin derivatives are more active than Aspirin.

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Assessment of the impact of PTGS1, PTGS2 and CYP2C9 polymorphisms on pain, effectiveness and safety of NSAID therapies

Postępy Higieny i Medycyny Doświadczalnej ◽

10.5604/01.3001.0014.5497 ◽

2020 ◽

Vol 74 ◽

pp. 504-516

Author(s):

Miriam Dawidowicz ◽

Agnieszka Kula ◽

Paweł Świętochowski ◽

Zofia Ostrowska

Keyword(s):

Enzymatic Activity ◽

Inflammatory Diseases ◽

Aspirin Resistance ◽

Nucleotide Polymorphisms ◽

Cyclooxygenase 1 ◽

Genes Encoding ◽

Cox 2 ◽

Anti Inflammatory ◽

The Impact ◽

Cox 1

Cyclooxygenase 1 and 2 (COX-1, COX-2) are enzymes that catalyze the first reaction in the arachidonic acid pathway. COXs are the therapeutic target for non-steroidal anti-inflammatory drugs. Inhibition of COX enzymatic activity has an analgesic, anti-inflammatory and sometimes antiplatelet effect. Single-nucleotide polymorphisms (SNPs) within genes encoding COX-1 and COX-2 (PTGS1, PTGS2) influence the risk of pain and their intensity in some diseases. They also affect the effectiveness of NSAID therapy in rheumatoid diseases. Moreover, the relationship between certain polymorphisms of PTGS2 and a higher risk of migraine and the development of aspirin resistance in the prophylaxis of cardiovascular diseases was demonstrated. The isoform of cytochrome P450, CYP2C9 has a significant influence on the efficacy and safety of NSAID use. It is responsible for the metabolism and speed of removal of these drugs. The occurrence of some of its polymorphic forms is associated with a decrease in CYP2C9 enzymatic activity, leading to changes in the pharmacokinetics and pharmacodynamics of NSAIDs. The prolonged half-life and decrease in clearance of these drugs lead to serious side effects such as hepatotoxicity, nephrotoxicity, anaphylactic reactions, cardiovascular or gastrointestinal incidents. Studies on polymorphisms of cyclooxygenases and CYP2C9 may improve the safety and efficacy of NSAIDs therapy by adjusting the dose to individual polymorphic variants, as well as expanding knowledge about the pathomechanism of inflammatory diseases.

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Differential expression of cyclooxygenase 1 and cyclooxygenase 2 in the bovine oviduct

Journal of Endocrinology ◽

10.1677/joe.1.06761 ◽

2006 ◽

Vol 191 (1) ◽

pp. 263-274 ◽

Cited By ~ 29

Author(s):

Simone Odau ◽

Christoph Gabler ◽

Christoph Holder ◽

Ralf Einspanier

Keyword(s):

Mrna Expression ◽

Estrous Cycle ◽

Luteal Phase ◽

Cellular Level ◽

Differential Distribution ◽

Cyclooxygenase 1 ◽

Epithelial Cell Layer ◽

Cox 2 ◽

Cycle Dependent ◽

Cox 1

The aim of the present study was to investigate the enzymes for the local prostaglandin (PG) biosynthesis present in the bovine oviduct during the estrous cycle to influence early reproductive events. Bovine oviducts were classified into four phases: pre-ovulatory, post-ovulatory, early-to-mid luteal, and late luteal phase, subdivided further into ipsi- or contralateral site and separated into ampulla or isthmus. Oviductal cells were gained by flushing the oviductal regions. Quantitative real-time reverse transcriptase-PCR was performed for the secretory and cytosolic phospholipases A2 (sPLA2IB, cPLA2α, and cPLA2β) and cyclooxygenases (COX-1 and COX-2) as the first step enzymes of PG synthesis. COX-1 and cPLA2β showed significant highest mRNA expression around and before ovulation compared with the luteal phase respectively. sPLA2IB and cPLA2α mRNA expression was unregulated during the estrous cycle. Regional differences in mRNA content were found for sPLA2IB with higher mRNA expression in the ampulla than in the isthmus. Western blot analysis revealed the highest COX-1 protein content in the early-to-mid luteal phase. Immunohistochemistry demonstrated that COX-1 was localized in epithelial and smooth muscle cells, whereas COX-2 was only localized in epithelial cells. COX-2 showed a differential distribution within the epithelial cell layer suggesting a regulation on a cellular level, although the COX-2 mRNA and protein amounts did not vary throughout the estrous cycle. A COX activity assay of oviductal cells revealed that COX activity originated predominantly from COX-1 than from COX-2. Treatment of primary oviductal cells with 10 pg/ml 17β-estradiol or 10 ng/ml progesterone resulted in a higher expression of COX-2 and cPLA2α, but not of the other enzymes. The expression pattern of these enzymes suggests that an estrous-cycle dependent and region-specific PG synthesis in the bovine oviduct may be required for a successful reproduction.

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The role of celecoxib as a potential inhibitor in the treatment of inflammatory diseases - a review

Current Medicinal Chemistry ◽

10.2174/0929867328666210910125229 ◽

2021 ◽

Vol 28 ◽

Author(s):

Josiane Viana Cruz ◽

Joaquín María Campos Rosa ◽

Njogu Mark Kimani ◽

Silvana Giuliatti ◽

Cleydson Breno Rodrigues dos Santos

Keyword(s):

Side Effects ◽

Inflammatory Diseases ◽

Structural Basis ◽

Potential Inhibitor ◽

Cyclooxygenase 1 ◽

Inflammatory Drugs ◽

Cox 2 ◽

Anti Inflammatory ◽

Cox 2 Inhibitors

: This article presents a simplified view of celecoxib as a potential inhibitor in the treatment of inflammatory diseases. The enzyme cyclooxygenase (COX) has, predominantly, two isoforms called cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). The former plays a constitutive role that is related to homeostatic effects in renal and platelets, while the latter is mainly responsible for induction of inflammatory effects. Since COX-2 plays an important role in the pathogenesis of inflammatory diseases, it has been signaled as a target for the planning of anti-inflammatory intermediates. Many inhibitors developed and planned for COX-2 inhibition have presented side effects to humans, mainly in the gastrointestinal and/or cardiovascular tract. Therefore, it is necessary to design new potential COX-2 inhibitors, which are relatively safe and without side effects. To this end, of the generation of non-steroidal anti-inflammatory drugs from “coxibs”, celecoxib is the only potent selective COX-2 inhibitor that is still commercially available. Thus, the compound celecoxib became a commercial prototype inhibitor for the development of anti-inflammatory agents for COX-2 enzyme. In this review, we provide highlights where such inhibition should provide a structural basis for the design of promising new non-steroidal anti-inflammatory drugs (NSAIDs) which act as COX-2 inhibitors with lesser side effects on the human body.

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Structural basis for subtype-specific inhibition of the P2X7 receptor

eLife ◽

10.7554/elife.22153 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 94

Author(s):

Akira Karasawa ◽

Toshimitsu Kawate

Keyword(s):

P2x7 Receptor ◽

Hydrophobic Interactions ◽

Binding Pocket ◽

Drug Binding ◽

Structural Basis ◽

Atp Binding ◽

Allosteric Site ◽

Channel Opening ◽

A Site ◽

Novel Drug

The P2X7 receptor is a non-selective cation channel activated by extracellular adenosine triphosphate (ATP). Chronic activation of P2X7 underlies many health problems such as pathologic pain, yet we lack effective antagonists due to poorly understood mechanisms of inhibition. Here we present crystal structures of a mammalian P2X7 receptor complexed with five structurally-unrelated antagonists. Unexpectedly, these drugs all bind to an allosteric site distinct from the ATP-binding pocket in a groove formed between two neighboring subunits. This novel drug-binding pocket accommodates a diversity of small molecules mainly through hydrophobic interactions. Functional assays propose that these compounds allosterically prevent narrowing of the drug-binding pocket and the turret-like architecture during channel opening, which is consistent with a site of action distal to the ATP-binding pocket. These novel mechanistic insights will facilitate the development of P2X7-specific drugs for treating human diseases.

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Meloxicam in pain syndrome treatment of comorbid diseases patients

Medical Council ◽

10.21518/2079-701x-2021-19-209-215 ◽

2021 ◽

pp. 209-215

Author(s):

O. A. Shavlovskaya ◽

I. A. Bokova ◽

N. I. Shavlovskiy

Keyword(s):

Gastrointestinal Tract ◽

Pain Syndrome ◽

Cardiovascular Risks ◽

Lower Back ◽

Cyclooxygenase 1 ◽

Inflammatory Drugs ◽

Cox 2 ◽

Comorbid Diseases ◽

Per Oral ◽

Cox 1

The issue nonsteroidal anti-inflammatory drugs (NSAIDs) use safety is associated with a high frequency of adverse events (AEs) from the gastrointestinal tract and cardiovascular risks. Patients with lower back pain (LBP) and osteoarthritis (OA), as a rule, have comorbid diseases, such as arterial hypertension (AH), coronary heart disease (CHD), gastrointestinal tract (GIT) diseases, which significantly complicates the appointment of NSAIDs. The main guideline in NSAIDs appointment is the selective ability to inhibit cyclooxygenase-1 and -2 (COX). The ratio of the activity of NSAIDs when blocking COX-1/COX-2 allows us to judge their potential toxicity. And, then higher the selectivity of NSAIDs, then lower its toxicity. For example, the ratio of COX-1/COX-2 in meloxicam is 0.33, diclofenac – 2.2, tenoxicam – 15, piroxicam – 33, indomethacin – 107. To the predominantly selective COX-2 NSAIDs include meloxicam, which has little effect on the GIT, the lowest relative risk (RR) of complications from the cardiovascular system (CVS). The therapeutic efficacy of meloxicam is comparable to piroxicam and diclofenac. A number of studies have shown the high efficacy of meloxicam, both with per oral (p/o) administration (7.5–15 mg/d), and with intramuscular (i/m) administration (1.5 ml), and when injected into trigger zones. Both with p/o and the injectable form of meloxicam has minimal GIT AEs and absence local reaction in the injection area. The drug can be recommended both as a combination therapy and prescribed in monotherapy.

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Involvement of cyclooxygenase 2 (COX-2) in intrinsic tone of isolated guinea pig

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y95-215 ◽

1995 ◽

Vol 73 (11) ◽

pp. 1561-1567 ◽

Cited By ~ 21

Author(s):

L. Charette ◽

C. Misquitta ◽

J. Guay ◽

D. Riendeau ◽

T. R. Jones

Keyword(s):

Guinea Pig ◽

Time Course ◽

Cyclooxygenase 2 ◽

Maximal Response ◽

Pharmacological Agents ◽

Cyclooxygenase 1 ◽

Inflammatory Drugs ◽

Cox 2 ◽

Cox 2 Inhibitors ◽

Cox 1

Indomethacin and related nonsteroidal anti-inflammatory drugs relax prostanoid-dependent intrinsic tone of isolated guinea pig trachea by inhibiting cyclooxygenase (COX). Recently, a second isoform of COX (COX-2) was discovered, which differed from COX-1 with respect to protein structure, transcriptional regulation, and susceptibility to inhibition by pharmacological agents. It is now known that indomethacin nonselectively inhibits COX-1 and COX-2, whereas NS-398 is a selective inhibitor of COX-2. In the present study we compared the activity of a selective (NS-398) and nonselective (indomethacin) COX-2 inhibitor on intrinsic tone of isolated guinea pig trachea. NS-398 ≥ indomethacin produced a reversal of intrinsic tone with a similar concentration-dependent (10 nM to 1 μM) time course (Tmax approximately 20–45 min), potency (EC50 1.7 and 5.6 nM, respectively), and maximal response. Contractions to cholinergic nerve stimulation (45 V, 0.5 ms, 0.1–32 Hz) and histamine were similarly modulated in tissues relaxed with the selective or nonselective COX-2 inhibitors. Immunoblot analyses showed that COX-2 protein synthesis was induced in both the cartilage and smooth muscle portions of the trachea during changes in intrinsic tone. These findings are consistent with pharmacological results and provide the first demonstration that prostanoid tone in isolated guinea pig trachea is dependent on COX-2 activity. The results also suggest that the activity of indomethacin in this preparation is likely related to COX-2 inhibition.Key words: cyclooxygenase 2, relaxation, guinea pig trachea, cyclooxygenase 1.

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