scholarly journals Effects of selective inhibition of cyclooxygenase and lipooxygenase pathways in follicle rupture and ovulation in the rat

Reproduction ◽  
2006 ◽  
Vol 132 (4) ◽  
pp. 571-577 ◽  
Author(s):  
M Gaytán ◽  
C Bellido ◽  
C Morales ◽  
J E Sánchez-Criado ◽  
F Gaytán

Treatment with non-steroidal anti-inflammatory drugs, either non-selective or selective cyclooxygenase-2 (COX-2) inhibitors, consistently impairs ovulation, indicating the essential role of COX-2/prostaglandins in the ovulatory process. Indomethacin, a potent inhibitor of both COX-1 and COX-2, induced several ovulatory alterations, consisting of a decrease in the number of oocytes effectively ovulated, trapping of oocytes inside the luteinized follicle, as well as abnormal follicle rupture at the basolateral sides, with release of the oocyte and follicular fluid to the interstitium. Yet, the precise role of prostaglandins in ovulation and whether some of the ovulatory defects induced by indomethacin are due to interference with additional components of the ovulatory cascade, beyond prostaglandin synthesis, are not completely understood. We have used gonadotrophin-primed immature rats to analyse whether, compared to indomethacin, selective inhibition of COX-2, with or without concomitant inhibition of COX-1, or selective inhibition of the lipooxygenase (LOX) pathway, induce similar ovulatory alterations. Immature rats (27 days of age) were injected PMSG (10 IU), and 48 h later hCG (10 IU) subcutaneously, and different anti-inflammatory drugs. Animals were killed at 21 h after hCG injection. Rats treated with the selective COX-2 inhibitor NS398 (10 mg/kg body weight, (bw)) showed alterations in follicle rupture as those treated with indomethacin (0.5 mg/rat), albeit affecting a lower number of follicles, irrespective of the concomitant inhibition of COX-1 with the selective inhibitor SC560 (10 mg/kg bw). Rats treated with the LOX inhibitor NDGA (300 mg/kg bw) did not show ovulatory alterations. These data indicate that the characteristic alterations of follicle rupture induced by indomethacin, are also induced by selective COX-2 inhibitors, strengthening the contention that prostaglandins play a crucial role in the spatial targeting of follicle rupture at the apex.

2004 ◽  
Vol 2 (1) ◽  
pp. 141-187 ◽  
Author(s):  
Sham Sondhi ◽  
Shefali Rajvanshi ◽  
Nirupma Singh ◽  
Shubhi Jain ◽  
Anand Lahoti

AbstractNon steroidal anti-inflammatory drugs are the most widely used medicines for relief of pain. These drugs have some side effects, particularly toxicity in the gastrointestinal tract and kidneys. Various approaches have been used for obtaining safer anti-inflammatory drugs. In this review we have summarized the recent developments in the following areas; (i) mode of action of NSAIDs (ii) Role of COX-1 & COX-2 in inflammation, (iii) Different approaches used to improve gastric tolerance i.e. chemical manipulation, formulation & co-administration, development of non specific (COX-1 & COX-2 inhibitors) and specific (COX-2 inhibitors) inflammation inhibitors, and development of inflammation inhibitors having a mode of action other than COX-1 & COX-2 inhibition. We have also focused on the safety of COX-2 inhibitors and the synthesis of heterocyclic compounds and their role as inflammation inhibitors.


2021 ◽  
Vol 28 ◽  
Author(s):  
Josiane Viana Cruz ◽  
Joaquín María Campos Rosa ◽  
Njogu Mark Kimani ◽  
Silvana Giuliatti ◽  
Cleydson Breno Rodrigues dos Santos

: 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.


2019 ◽  
Vol 9 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Courtney L. Fisher ◽  
Stacie L. Demel

Background: Saccular intracranial aneurysms (IAs) are outpouchings of the vessel wall of intracranial arteries. Rupture of IAs results in subarachnoid hemorrhage which is associated with high morbidity and mortality. Surgical interventions, such as clipping and coiling, have associated risks. Currently, there are no proven pharmacological treatments to prevent the growth or rupture of IAs. Infiltration of proinflammatory cytokines in response to increased wall sheer stress is a hallmark of IA. Nonsteroidal anti-inflammatory drugs (NSAIDs) are being investigated as potential therapeutic agents for reduction in growth and/or prevention of IA through inhibition of inflammatory pathways. Summary: This review will discuss the role of NSAIDs in attenuating the inflammation that drives IA progression and rupture. There are two main subtypes of NSAIDs, nonselective COX and selective COX-2 inhibitors, both of which have merit in treating IA. Evidence will be presented which shows that NSAIDs inhibit several key inflammatory mediators involved in IA progression including nuclear factor-κB, tumor necrosis factor-α, and matrix metalloproteinases. In addition, the role of NSAIDs in limiting inflammatory cell adhesion to endothelial cells and attenuating endothelial cell senescence will be discussed. Key Messages: There is an abundance of basic science and preclinical data that support NSAIDs as a promising treatment for IA. Additionally, a combination treatment strategy of low-dose aspirin given concomitantly with a selective COX-2 inhibitor may result in a reduced side effect profile compared to aspirin or selective COX-2 inhibitor use alone. Several large clinical trials are currently planned to further investigate the efficacy of NSAIDs as an effective nonsurgical treatment for IAs.


2003 ◽  
Vol 17 (5) ◽  
pp. 335-338 ◽  
Author(s):  
Andreas Maetzel

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 aregiven 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.


2018 ◽  
Vol 88 (2) ◽  
Author(s):  
Raffaele Rotunno ◽  
Igino Oppo ◽  
Gabriele Saetta ◽  
Pietro Aveta ◽  
Sergio Bruno

One of the potential cardiotoxic action of anti-inflammatory drugs is the occurrence of heart failure (HF), due to their effects on fluid retention and blood pressure. The risk of hospitalization for HF is roughly doubled for both Coxibs, cyclooxygenase-1 (COX-1) and cyclooxygenase- 2 (COX-2) inhibitors, and all the conventional nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs are also associated with a risk of vascular thrombosis, which for NSAIDs is different in relation to their different ability to inhibit COX-1 and COX-2. The cardiovascular toxicity of these drugs in the direction of HF follow different pathways respect to their related vascular thrombosis toxicity and involves, in particular, the renal prostaglandins, PGE2 and prostacyclin, mostly synthesized by COX-2. In the kidneys the PGs perform a direct vasodilatory action, e.g. by means of non-contrasting angiotensin mechanisms, and for this reason nimesulide effects on renal microcirculation are independent from the prevalence of intrarenal renin angiotensin aldosterone system (RAAS) activity. Conversely, nimesulide reduces sodium tubular urinary flow only in presence of intrarenal RAAS.


1999 ◽  
Vol 12 (5) ◽  
pp. 401-411
Author(s):  
Julienne K. Kirk ◽  
Jennifer M. Hamilton ◽  
Kathy C. Phelps

Identification of two isoforms of cyclooxygenase, COX-1 and COX-2, has initiated a revolution in the approach to pharmacologie pain management. It has been further determined that inhibition of COX-2 reduces inflammation, and inhibition of COX-1 compromises gastrointestinal mucosal integrity. As traditional nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both COX-1 and COX-2, gastrointestinal ulceration can develop in association with the use of these agents to control pain and inflammation. An ideal NSAID would, therefore, inhibit COX-2 to provide anti-inflammatory effects while leaving COX-1, and, therefore, gastrointestinal mucosa, unaffected. Two selective COX-2 inhibitors have recently been approved in the United States. Celecoxib (Celebrex, G.D. Searle & Co.) and rofecoxib (Vioxxj, Merck & Co., Inc.) are indicated for the treatment of osteoarthritis. Also, celecoxib is approved for rheumatoid arthritis. Rofecoxib is also approved for the treatment of acute pain and dysmenorrhea. Both agents have displayed similar efficacy to traditional NSAIDs. In addition, endoscopically detected gastrointestinal ulceration is reduced versus older NSAIDs. Further evaluation of selective COX-2 inhibitors will elucidate long-term efficacy, safety, and potential reduction of health care dollars spent on hospitalization and treatment for NSAID-induced gastrointestinal toxicity.


2021 ◽  
pp. 30-39
Author(s):  
Prateek Paul ◽  
Manvi .

For prostaglandin production, the enzyme cyclooxygenase (COX) is required. The two COX isoforms are constitutive COX-1 (which is responsible for physiological functions) and inducible COX-2 (involved in inflammation). COX inhibition explains both the medicinal (inhibition of COX-2) and negative effects (inhibition of COX-1) effects of non-steroidal anti-inflammatory medicines (NSAIDs). Nonsteroidal anti-inflammatory medicines (NSAIDs) act by blocking the enzyme cyclooxygenase (COX), which produces prostaglandins (PGs). To a greater or lesser extent, they share similar side effects, such as stomach and renal toxicity. According to a recent study, there are at least two COX isoenzymes. COX-1 is a naturally occurring enzyme that creates prostaglandins (PGs), which protect the stomach and kidneys. Aspirin's well-known anti-cancer impact could also be related to its influence on COX-2, which is expressed in this condition. As a result, selective COX-2 inhibitors may have new therapeutic potential as anticancer drugs, as well as in preventing premature labor and maybe reducing the progression of Alzheimer's disease.


1995 ◽  
Vol 73 (11) ◽  
pp. 1561-1567 ◽  
Author(s):  
L. Charette ◽  
C. Misquitta ◽  
J. Guay ◽  
D. Riendeau ◽  
T. R. Jones

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.


Sign in / Sign up

Export Citation Format

Share Document