Systemic biosynthesis of prostacyclin by cyclooxygenase (COX)-2: the human pharmacology of a selective inhibitor of COX-2

Does Celecoxib Prescription for Pain Management Affect Post-tonsillectomy Hemorrhage Requiring Surgery? A Retrospective Observational Cohort Study

BACKGROUND

Adenotonsillectomy and tonsillectomy (referred to as tonsillectomy hereafter) are common pediatric surgeries. Postoperative complications include hemorrhage requiring surgery (2 to 3% of cases) and pain. Although nonsteroidal anti-inflammatory drugs are commonly administered for postsurgical pain, controversy exists regarding bleeding risk with cyclooxygenase-1 inhibition and associated platelet dysfunction. Preliminary evidence suggests selective cyclooxygenase-2 inhibitors, for example celecoxib, effectively manage pain without adverse events including bleeding. Given the paucity of data for routine celecoxib use after tonsillectomy, this study was designed to investigate the association between postoperative celecoxib prescription and post-tonsillectomy hemorrhage requiring surgery using chart-review data from the Children's Hospital of Eastern Ontario.

METHODS

After ethics approval, a retrospective single-center observational cohort study was performed in children less than 18 yr of age undergoing tonsillectomy from January 2007 to December 2017. Cases of adenoidectomy alone were excluded due to low bleed rates. The primary outcome was the proportion of patients with post-tonsillectomy hemorrhage requiring surgery. The association between a celecoxib prescription and post-tonsillectomy hemorrhage requiring surgery was estimated using inverse probability of treatment weighting based on propensity scores and using generalized estimating equations to accommodate clustering by surgeon.

RESULTS

An initial patient cohort of 6,468 was identified, and 5,846 children with complete data were included in analyses. Median (interquartile range) age was 6.10 (4.40, 9.00) yr, and 46% were female. In the cohort, 28.1% (n = 1,644) were prescribed celecoxib. Among the 4,996 tonsillectomy patients, 1.7% (n = 86) experienced post-tonsillectomy hemorrhage requiring surgery. The proportion with post-tonsillectomy hemorrhage requiring surgery among patients who had a tonsillectomy and were or were not prescribed celecoxib was 1.94% (30 of 1,548; 95% CI, 1.36 to 2.75) and 1.62% (56 of 3,448; 95% CI, 1.25 to 2.10), respectively. Modeling did not identify an association between celecoxib prescription and increased odds of post-tonsillectomy hemorrhage requiring surgery (odds ratio = 1.4; 95% CI, 0.85 to 2.31; P = 0.20).

CONCLUSIONS

Celecoxib does not significantly increase the odds of post-tonsillectomy hemorrhage requiring surgery, after adjusting for covariates. This large pediatric cohort study of celecoxib administered after tonsillectomy provides compelling evidence for safety but requires confirmation with a multisite randomized controlled trial.

EDITOR’S PERSPECTIVE

Aspirin in Primary Prevention: Looking for Those Who Enjoy It

Based on a wealth of evidence, aspirin is one of the cornerstones of secondary prevention of cardiovascular disease. However, despite several studies showing efficacy also in primary prevention, an unopposed excess risk of bleeding leading to a very thin safety margin is evident in subjects without a clear acute cardiovascular event. Overall, the variability in recommendations from different scientific societies for aspirin use in primary prevention is a classic example of failure of simple risk stratification models based on competing risks (atherothrombosis vs. bleeding), perceived to be opposed but intertwined at the pathophysiological level. Notably, cardiovascular risk is dynamic in nature and cannot be accurately captured by scores, which do not always consider risk enhancers. Furthermore, the widespread use of other potent medications in primary prevention, such as lipid-lowering and anti-hypertensive drugs, might be reducing the benefit of aspirin in recent trials. Some authors, drawing from specific pathophysiological data, have suggested that specific subgroups might benefit more from aspirin. This includes patients with diabetes and those with obesity; sex-based differences are considered as well. Moreover, molecular analysis of platelet reactivity has been proposed. A beneficial effect of aspirin has also been demonstrated for the prevention of cancer, especially colorectal. This review explores evidence and controversies concerning the use of aspirin in primary prevention, considering new perspectives in order to provide a comprehensive individualized approach.

Arachidonic acid in aging: New roles for old players

BACKGROUND

Arachidonic acid (AA), one of the most ubiquitous polyunsaturated fatty acids (PUFAs), provides fluidity to mammalian cell membranes. It is derived from linoleic acid (LA) and can be transformed into various bioactive metabolites, including prostaglandins (PGs), thromboxanes (TXs), lipoxins (LXs), hydroxy-eicosatetraenoic acids (HETEs), leukotrienes (LTs), and epoxyeicosatrienoic acids (EETs), by different pathways. All these processes are involved in AA metabolism. Currently, in the context of an increasingly visible aging world population, several scholars have revealed the essential role of AA metabolism in osteoporosis, chronic obstructive pulmonary disease, and many other aging diseases.

AIM OF REVIEW

Although there are some reviews describing the role of AA in some specific diseases, there seems to be no or little information on the role of AA metabolism in aging tissues or organs. This review scrutinizes and highlights the role of AA metabolism in aging and provides a new idea for strategies for treating aging-related diseases.

KEY SCIENTIFIC CONCEPTS OF REVIEW

As a member of lipid metabolism, AA metabolism regulates the important lipids that interfere with the aging in several ways. We present a comprehensivereviewofthe role ofAA metabolism in aging, with the aim of relieving the extreme suffering of families and the heavy economic burden on society caused by age-related diseases. We also collected and summarized data on anti-aging therapies associated with AA metabolism, with the expectation of identifying a novel and efficient way to protect against aging.

3D-QSAR pharmacophore modeling, virtual screening, molecular docking, MD simulations, in vitro and in vivo studies to identify potential anti-hyperplasia drugs

Psoriasis is a common immune-mediated skin condition characterized by aberrant keratinocytes and cell proliferation. The purpose of this study was to explore the FDA-approved drugs by 3D-QSAR pharmacophore model and evaluate their efficiency by in-silico, in vitro, and in vivo psoriasis animal model. A 3D-QSAR pharmacophore model was developed by utilizing HypoGen algorithm using the structural features of 48 diaryl derivatives with diverse molecular patterns. The model was validated by a test set of 27 compounds, by cost analysis method, and Fischer's randomization test. The correlation coefficient of the best model (Hypo2) was 0.9601 for the training set while it was 0.805 for the test set. The selected model was taken as a 3D query for the virtual screening of over 3000 FDA-approved drugs. Compounds mapped with the pharmacophore model were further screened through molecular docking. The hits that showed the best docking results were screened through in silico skin toxicity approach. Top five hits were selected for the MD simulation studies. Based on MD simulations results, the best two hit molecules, that is, ebastine (Ebs) and mebeverine (Mbv) were selected for in vitro and in vivo antioxidant studies performed in mice. TNF-α and COX pro-inflammatory mediators, biochemical assays, histopathological analyses, and immunohistochemistry observations confirmed the anti-inflammatory response of the selected drugs. Based on these findings, it appeared that Ebs can effectively treat psoriasis-like skin lesions and down-regulate inflammatory responses which was consistent with docking predictions and could potentially be employed for further research on inflammation-related skin illnesses such as psoriasis.

Why Pharmacovigilance of Non-steroidal Anti-inflammatory Drugs is Important in India?

BACKGROUND

Non-steroidal Anti-Inflammatory Drugs (NSAIDs) are among the drugs that are most regularly administered to manage inflammation and pain. Over-the-Counter (OTC) NSAIDs are widely accessible, particularly in developing countries like India. This casual approach to using NSAIDs may operate as a magnet for NSAID-related adverse drug reactions (ADRs) among patients.

OBJECTIVES

As patients in India are less informed about the appropriate use of NSAIDs and consumption patttern, adverse drug reactions, and the importance of reporting ADRs, the current study's objective is to promote patient safety by using pharmacovigilance as a tool to educate patients.

METHODS

A targeted literature methodology was utilized to gather the data pertaining to NSAIDs, their ADRs and their pharmacovigilance. Different scientific databases, such as Science Direct, PubMed, Wiley Online Library, Springer, and Google Scholar, along with authentic textbooks, were explored as reference literature.

RESULTS

In general, NSAIDs consumption pattern depends upon the different age groups. Around 1.6 billion tablets of NSAIDs are consumed in India for ailments, such as headaches, arthritis, menstrual cramps, osteoarthritis, back pain, rheumatoid arthritis, gout, osteoporosis, tendinitis, cancer pain and chronic pain. Common ADRs of NSAIDs include nausea, vomiting, headache, gastritis, abdominal pain, and diarrhoea. Also, they can cause renal damage and cardiovascular problems if not consumed in a dose-dependent manner. However, Diclofenac and Ibuprofen have both been linked to depression and dementia. There have been reports of aplastic anaemia, agranulocytosis linked to phenylbutazone, Stevens-Johnson, and Lyell's syndrome linked to isoxicam and piroxicam, as well as the vulnerability of new-borns to Reye's syndrome after aspirin use. Lack of awareness, time constraints and unpredictability, poor training in ADRs identification, etc., are some of the reasons for the under-reporting of ADR of NSAIDs in India.

CONCLUSION

In order to rationally prescribe NSAIDs, it is essential to be aware of probable ADR's and establish prescription guidelines. Prescribers' behaviour can be changed toward excellent prescribing practices by conducting routine prescription assessments dealing with NSAIDs and providing feedback. In the near future, it will be critical to strengthen ADR data management and expand the reach of pharmacovigilance programs, ADR monitoring centers, and healthcare professionals' especially pharmacists' training in rural locations.

Widening the Prostacyclin Paradigm: Tissue Fibroblasts Are a Critical Site of Production and Antithrombotic Protection

BACKGROUND

Prostacyclin is a fundamental signaling pathway traditionally associated with the cardiovascular system and protection against thrombosis but which also has regulatory functions in fibrosis, proliferation, and immunity. Prevailing dogma states that prostacyclin is principally derived from vascular endothelium, although it is known that other cells can also synthesize it. However, the role of nonendothelial sources in prostacyclin production has not been systematically evaluated resulting in an underappreciation of their importance relative to better characterized endothelial sources.

METHODS

To address this, we have used novel endothelial cell-specific and fibroblast-specific COX (cyclo-oxygenase) and prostacyclin synthase knockout mice and cells freshly isolated from mouse and human lung tissue. We have assessed prostacyclin release by immunoassay and thrombosis in vivo using an FeCl3-induced carotid artery injury model.

RESULTS

We found that in arteries, endothelial cells are the main source of prostacyclin but that in the lung, and other tissues, prostacyclin production occurs largely independently of endothelial and vascular smooth muscle cells. Instead, in mouse and human lung, prostacyclin production was strongly associated with fibroblasts. By comparison, microvascular endothelial cells from the lung showed weak prostacyclin synthetic capacity compared with those isolated from large arteries. Prostacyclin derived from fibroblasts and other nonendothelial sources was seen to contribute to antithrombotic protection.

CONCLUSIONS

These observations define a new paradigm in prostacyclin biology in which fibroblast/nonendothelial-derived prostacyclin works in parallel with endothelium-derived prostanoids to control thrombotic risk and potentially a broad range of other biology. Although generation of prostacyclin by fibroblasts has been shown previously, the scale and systemic activity was unappreciated. As such, this represents a basic change in our understanding and may provide new insight into how diseases of the lung result in cardiovascular risk.

Mast cell-mediated immune regulation in health and disease

Mast cells are important components of the immune system, and they perform pro-inflammatory as well as anti-inflammatory roles in the complex process of immune regulation in health and disease. Because of their strategic perivascular localization, sensitivity and adaptability to the microenvironment, and ability to release a variety of preformed and newly synthesized effector molecules, mast cells perform unique functions in almost all organs. Additionally, Mast cells express a wide range of surface and cytoplasmic receptors which enable them to respond to a variety of cytokines, chemicals, and pathogens. The mast cell's role as a cellular interface between external and internal environments as well as between vasculature and tissues is critical for protection and repair. Mast cell interactions with different immune and nonimmune cells through secreted inflammatory mediators may also turn in favor of disease promoting agents. First and forefront, mast cells are well recognized for their multifaceted functions in allergic diseases. Reciprocal communication between mast cells and endothelial cells in the presence of bacterial toxins in chronic/sub-clinical infections induce persistent vascular inflammation. We have shown that mast cell proteases and histamine induce endothelial inflammatory responses that are synergistically amplified by bacterial toxins. Mast cells have been shown to exacerbate vascular changes in normal states as well as in chronic or subclinical infections, particularly among cigarette smokers. Furthermore, a potential role of mast cells in SARS-CoV-2-induced dysfunction of the capillary-alveolar interface adds to the growing understanding of mast cells in viral infections. The interaction between mast cells and microglial cells in the brain further highlights their significance in neuroinflammation. This review highlights the significant role of mast cells as the interface that acts as sensor and early responder through interactions with cells in systemic organs and the nervous system.

The leukotriene B4 receptors BLT1 and BLT2 as potential therapeutic targets

Leukotriene B4 (LTB4 ) was recognized as an arachidonate-derived chemotactic factor for inflammatory cells and an important drug target even before the molecular identification of its receptors. We cloned the high- and low-affinity LTB4 receptors, BLT1 and BLT2, respectively, and examined their functions by generating and studying gene-targeted mice. BLT1 is involved in the pathogenesis of various inflammatory and immune diseases, including asthma, psoriasis, contact dermatitis, allergic conjunctivitis, age-related macular degeneration, and immune complex-mediated glomerulonephritis. Meanwhile, BLT2 is a high-affinity receptor for 12-hydroxyheptadecatrienoic acid, which is involved in the maintenance of dermal and intestinal barrier function, and the acceleration of skin and corneal wound healing. Thus, BLT1 antagonists and BLT2 agonists are promising candidates in the treatment of inflammatory diseases.

Efficacy of Aceclofenac and Ilaprazole Combination Therapy versus Celecoxib Monotherapy for Treating NSAID-Induced Dyspepsia in Lumbar Spinal Stenosis Patients

Background and Objectives: Dyspepsia is a common adverse event associated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with lumbar spinal stenosis. Although proton pump and cyclooxygenase-2 inhibitors are potential treatment options, the optimal strategy remains unclear. This study aimed to compare the efficacy and safety of combination therapy with aceclofenac and ilaprazole versus celecoxib monotherapy for the treatment of dyspepsia caused by NSAID use in patients with lumbar spinal stenosis. Materials and Methods: This prospective, double-blind, randomized, actively controlled study was conducted at Seoul National University Bundang Hospital in South Korea from July 2020 to September 2021. The participants were randomized into one of two treatment groups: celecoxib monotherapy (control group) and combination therapy with aceclofenac and ilaprazole (test group). The primary efficacy endpoint was the mean change in the Short-Form Leeds Dyspepsia Questionnaire (SF-LDQ) scores from baseline to treatment week 8. The secondary efficacy endpoint was the mean change in Short-Form-12 (SF-12) scores from baseline (week 0) to treatment week 8. Results: The study enrolled 140 patients who were randomly assigned to receive combination therapy with aceclofenac and, ilaprazole or celecoxib. In the per protocol set, the mean change in SF-LDQ scores from week 0 to week 8 was -0.51 ± 4.78 and 1.85 ± 6.70 in the combination therapy and celecoxib group, respectively (p = 0.054). SF-12 scores did not differ significantly between the two groups. Adverse events were reported in both groups, but there was no significant difference in incidence. Conclusions: Combination therapy with aceclofenac and ilaprazole can be a treatment option for NSAID-induced dyspepsia in some situations.

Systemic Photoprotection in Melanoma and Non-Melanoma Skin Cancer

Non-melanoma skin cancers (NMSCs), which include basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and actinic keratosis (AK), are the most common cancer diseases in the Caucasian race. If diagnosed late and improperly treated, BCC and SCC can become locally advanced and metastasize. Malignant melanoma (MM) is less frequent but more lethal than NMSC. Given the individual and social burdens of skin cancers, performing an adequate prevention is needed. Ultraviolet (UV) ray exposure is one of the main risk factors for skin cancer. Thus, the first-choice prevention strategy is represented by photoprotection that can be both topical and systemic. The latter consists of the oral administration of molecules which protect human skin against the damaging effects of UV rays, acting through antioxidant, anti-inflammatory, or immunomodulator mechanisms. Although several compounds are commonly used for photoprotection, only a few molecules have demonstrated their effectiveness in clinical trials and have been included in international guidelines for NMSC prevention (i.e., nicotinamide and retinoids). Moreover, none of them have been demonstrated as able to prevent MM. Clinical and preclinical data regarding the most common compounds used for systemic photoprotection are reported in this review, with a focus on the main mechanisms involved in their photoprotective properties.

The Safety of Celecoxib as an Acute Treatment for Migraine: A Narrative Review

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been the first-line choice for the acute treatment of migraine attacks for decades; however, the safety of a particular NSAID is related to its treatment dose, duration, and mechanism of action. Although adverse event (AE) risks differ substantially among individual migraine treatments, increased or prolonged exposure to any NSAID elevates risks and severity of AEs.

METHODS

For this narrative review, we conducted a literature search of PubMed until July 2022, focusing on the history, mechanism of action, and treatment guidelines informing the safety and efficacy of celecoxib oral solution for the acute treatment of migraine attacks.

RESULTS

Here we discuss the mechanisms of action of nonselective NSAIDs vs. cyclooxygenase-2 (COX-2) inhibitors, and how these mechanisms underlie the AEs associated with these treatments. We review the clinical trials that influenced the regulatory history of NSAIDs, specifically COX-2 inhibitors, the role of traditional and new formulations of NSAIDs including celecoxib oral solution, and special considerations in the acute treatment of migraine attacks.

CONCLUSIONS

Low-dose formulations of NSAIDs, such as celecoxib oral solution, provide acute migraine analgesia with similar or fewer associated cardiovascular and gastrointestinal events than previous formulations.

Disconnect between COX-2 selective inhibition and cardiovascular risk in preclinical models

INTRODUCTION

Secondary pharmacology profiling is routinely applied in pharmaceutical drug discovery to investigate the pharmaceutical effects of a drug at molecular targets distinct from (off-target) the intended therapeutic molecular target (on-target). Data from a randomized, placebo-controlled clinical trial, the APPROVe (Adenomatous Polyp Prevention on VIOXX, rofecoxib) trial, raised significant concerns about COX-2 inhibition as a primary or secondary target, shaping the screening and decision-making processes of some pharmaceutical companies. COX-2 is often included in off-target screens due to cardiovascular (CV) safety concerns about secondary interactions with this target. Several potential mechanisms of COX-2-mediated myocardial infarctions have been considered including, effects on platelet stickiness/aggregation, vasal tone and blood pressure, and endothelial cell activation. In the present study, we focused on each of these mechanisms as potential effects of COX-2 inhibitors, to find evidence of mechanism using various in vitro and in vivo preclinical models.

METHODS

Compounds tested in the study, with a range of COX-2 selectivity, included rofecoxib, celecoxib, etodolac, and meloxicam. Compounds were screened for inhibition of COX-2 vs COX-1 enzymatic activity, ex vivo platelet aggregation (using whole blood from multiple species), ex vivo canine femoral vascular ring model, in vitro human endothelial cell activation (with and without COX-2 induction), and in vivo cardiovascular assessment (anesthetized dog).

RESULTS

The COX-2 binding assessment generally confirmed the COX-2 selectivity previously reported. COX-2 inhibitors did not have effects on platelet function (spontaneous aggregation or inhibition of aggregation), cardiovascular parameters (mean arterial pressure, heart rate, and left ventricular contractility), or endothelial cell activation. However, rofecoxib uniquely produced an endothelial mediated constriction response in canine femoral arteries.

CONCLUSION

Our data suggest that rofecoxib-related cardiovascular events in humans are not predicted by COX-2 potency or selectivity. In addition, the vascular ring model suggested possible adverse cardiovascular effects by COX-2 inhibitors, although these effects were not seen in vivo studies. These results may also suggest that COX-2 inhibition alone is not responsible for rofecoxib-mediated adverse cardiovascular outcomes.

The Pleiotropic Role of Extracellular ATP in Myocardial Remodelling

Myocardial remodelling is a molecular, cellular, and interstitial adaptation of the heart in response to altered environmental demands. The heart undergoes reversible physiological remodelling in response to changes in mechanical loading or irreversible pathological remodelling induced by neurohumoral factors and chronic stress, leading to heart failure. Adenosine triphosphate (ATP) is one of the potent mediators in cardiovascular signalling that act on the ligand-gated (P2X) and G-protein-coupled (P2Y) purinoceptors via the autocrine or paracrine manners. These activations mediate numerous intracellular communications by modulating the production of other messengers, including calcium, growth factors, cytokines, and nitric oxide. ATP is known to play a pleiotropic role in cardiovascular pathophysiology, making it a reliable biomarker for cardiac protection. This review outlines the sources of ATP released under physiological and pathological stress and its cell-specific mechanism of action. We further highlight a series of cardiovascular cell-to-cell communications of extracellular ATP signalling cascades in cardiac remodelling, which can be seen in hypertension, ischemia/reperfusion injury, fibrosis, hypertrophy, and atrophy. Finally, we summarize current pharmacological intervention using the ATP network as a target for cardiac protection. A better understanding of ATP communication in myocardial remodelling could be worthwhile for future drug development and repurposing and the management of cardiovascular diseases.

Fifty years with aspirin and platelets

In 2021, we reached the 50th anniversary of the publication of Sir John Vane's seminal paper in Nature New Biology describing the experiments supporting his mechanistic hypothesis that inhibition of prostaglandin synthesis might explain the main pharmacological effects of aspirin and aspirin-like drugs, that is, reduction in pain, fever and inflammation. Bengt Samuelsson's subsequent discoveries elucidating the cyclooxygenase pathway of platelet arachidonic acid metabolism motivated my research interest towards measuring platelet thromboxane A₂ biosynthesis as a tool to investigate the clinical pharmacology of cyclooxygenase inhibition by aspirin in health and disease. What followed was a long, winding road of clinical research leading to the characterization of low-dose aspirin as a life-saving antiplatelet drug that still represents the cornerstone of antithrombotic therapy. Having witnessed and participated in these 50 years of aspirin research, I thought of providing a personal testimony of how things developed and eventually led to a remarkable success story of independent research.

Mechanism of platelet activation and potential therapeutic effects of natural drugs

BACKGROUND

Cardiovascular disease is one of the most concerning chronic diseases in the world. Many studies have shown that platelet overactivation is a very important factor in the occurrence and development of cardiovascular diseases. At present, the widely used antiplatelet drugs have some defects, such as drug resistance and adverse reactions.

PURPOSE

The purpose of this article is to summarize the main mechanisms and pathways of platelet activation, the main targets of antiplatelet aggregation, and the antiplatelet aggregation components of natural drugs and their mechanisms of action to provide new research ideas for the development and application of antiplatelet drugs.

STUDY DESIGN AND METHODS

In this review, we systematically searched the PubMed, Google Scholar, Web of Science, and CNKI databases and selected studies based on predefined eligibility criteria. We then assessed their quality and extracted data.

RESULTS

ADP, AA, THR, AF, collagen, SDF-1α, and Ca²⁺ can induce platelet aggregation and trigger thrombosis. Natural drugs have a good inhibitory effect on platelet activation. More than 50 kinds of natural drugs and over 120 kinds of chemical compounds, including flavonoids, alkaloids, saponins, terpenoids, coumarins, and organic acids, have significantly inhibited platelet activation activity. The MAPK pathway, cGMP-PKG pathway, cAMP-PKA pathway, PI3K-AKT pathway, PTK pathway, PLC pathway, and AA pathway are the main mechanisms and pathways of platelet activation.

CONCLUSION

Natural drugs and their active ingredients have shown good activity and application prospects in anti-platelet aggregation. We hope that this review provides new research ideas for the development and application of antiplatelet drugs.

Inflammation context in Alzheimer's disease, a relationship intricate to define

Alzheimer's disease (AD), the most common form of dementia, is characterized by the accumulation of amyloid β (Aβ) and hyperphosphorylated tau protein aggregates. Importantly, Aβ and tau species are able to activate astrocytes and microglia, which release several proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β), together with reactive oxygen (ROS) and nitrogen species (RNS), triggering neuroinflammation. However, this inflammatory response has a dual function: it can play a protective role by increasing Aβ degradation and clearance, but it can also contribute to Aβ and tau overproduction and induce neurodegeneration and synaptic loss. Due to the significant role of inflammation in the pathogenesis of AD, several inflammatory mediators have been proposed as AD markers, such as TNF-α, IL-1β, Iba-1, GFAP, NF-κB, TLR2, and MHCII. Importantly, the use of anti-inflammatory drugs such as NSAIDs has emerged as a potential treatment against AD. Moreover, diseases related to systemic or local inflammation, including infections, cerebrovascular accidents, and obesity, have been proposed as risk factors for the development of AD. In the following review, we focus on key inflammatory processes associated with AD pathogenesis.

Potent Analgesic Action of 2-acetoxy-5-(2-4 (trifluoromethyl)-phenethylamino)-benzoic Acid (Flusalazine) in Experimental Mice

PURPOSE

Nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase (COX)-2 selective inhibitors are the most widely used drugs to treat pain. Conventional NSAIDs and COX-2 selective inhibitors, however, cause several side effects such as gastric damage, kidney damage, and cardiovascular problems. Our previous study showed that 2-acetoxy-5-(2-4-(trifluoromethyl)-phenethylamino)-benzoic acid ie, flusalazine (also known as ND-07), which exerts dual actions by serving both as an anti-inflammatory agent and a free radical scavenger, is an effective and safe treatment for severe inflammatory diseases in mice. The goal of the present study was to examine the potential analgesic action and safety of flusalazine in mice models of pain.

METHODS AND RESULTS

Flusalazine showed a significant analgesic effect in an acetic acid-induced abdominal constriction model. Likewise, total paw licking was reduced significantly in neurogenic (early stage) and inflammatory (late stage) pain induced by formalin in flusalazine-treated mice. In the tail immersion test, flusalazine significantly increased tail withdrawal time at 2 h after its administration. Also, the formation of paw edema in the flusalazine-treated group was significantly inhibited in a carrageenan-induced inflammatory pain model. Gastric damage was not induced by flusalazine even up to 1000 mg/kg, while aspirin and indomethacin caused critical gastric bleeding.

CONCLUSION

These findings suggest that flusalazine's safety profile and analgesic effects have high translational potential for the clinical treatment of patients experiencing pain.

Microbes Contribute to Chemopreventive Efficacy, Intestinal Tumorigenesis, and the Metabolome

Bacteria are believed to play an important role in intestinal tumorigenesis and contribute to both gut luminal and circulating metabolites. Celecoxib, a selective cyclooxygenase-2 inhibitor, alters gut bacteria and metabolites in association with suppressing the development of intestinal polyps in mice. The current study sought to evaluate whether celecoxib exerts its chemopreventive effects, in part, through intestinal bacteria and metabolomic alterations. Using ApcMin/+ mice, we demonstrated that treatment with broad-spectrum antibiotics (ABx) reduced abundance of gut bacteria and attenuated the ability of celecoxib to suppress intestinal tumorigenesis. Use of ABx also impaired celecoxib's ability to shift microbial populations and gut luminal and circulating metabolites. Treatment with ABx alone markedly reduced tumor number and size in ApcMin/+ mice, in conjunction with profoundly altering the metabolite profiles of the intestinal lumen and blood. Many of the metabolite changes in the gut and circulation overlapped and included shifts in microbially derived metabolites. To complement these findings in mice, we evaluated the effects of ABx on circulating metabolites in patients with colon cancer. This showed that ABx treatment led to a shift in blood metabolites, including several that were of bacterial origin. Importantly, changes in metabolites in patients given ABx overlapped with alterations found in mice that also received ABx. Taken together, these findings suggest a potential role for bacterial metabolites in mediating both the chemopreventive effects of celecoxib and intestinal tumor growth.

PREVENTION RELEVANCE

This study demonstrates novel mechanisms by which chemopreventive agents exert their effects and gut microbiota impact intestinal tumor development. These findings have the potential to lead to improved cancer prevention strategies by modulating microbes and their metabolites.

Aspirin sensitivity of PIK3CA-mutated Colorectal Cancer: potential mechanisms revisited

PIK3CA mutations are amongst the most prevalent somatic mutations in cancer and are associated with resistance to first-line treatment along with low survival rates in a variety of malignancies. There is evidence that patients carrying PIK3CA mutations may benefit from treatment with acetylsalicylic acid, commonly known as aspirin, particularly in the setting of colorectal cancer. In this regard, it has been clarified that Class IA Phosphatidylinositol 3-kinases (PI3K), whose catalytic subunit p110α is encoded by the PIK3CA gene, are involved in signal transduction that regulates cell cycle, cell growth, and metabolism and, if disturbed, induces carcinogenic effects. Although PI3K is associated with pro-inflammatory cyclooxygenase-2 (COX-2) expression and signaling, and COX-2 is among the best-studied targets of aspirin, the mechanisms behind this clinically relevant phenomenon are still unclear. Indeed, there is further evidence that the protective, anti-carcinogenic effect of aspirin in this setting may be mediated in a COX-independent manner. However, until now the understanding of aspirin's prostaglandin-independent mode of action is poor. This review will provide an overview of the current literature on this topic and aims to analyze possible mechanisms and targets behind the aspirin sensitivity of PIK3CA-mutated cancers.

Acetylsalicylic Acid Is Associated With a Lower Prevalence of Ascending Aortic Aneurysm and a Decreased Aortic Expression of Cyclooxygenase 2

Background Acetylsalicylic acid (ASA) therapy has been associated with a reduced prevalence and growth rate of abdominal as well as intracranial aneurysms, but the relationship between ASA and ascending aortic aneurysm formation remains largely unknown. The aim of the present study was to investigate whether ASA therapy is associated with a lower prevalence of ascending aortic aneurysm in a surgical cohort. Methods and Results One thousand seven hundred patients undergoing open-heart surgery for ascending aortic aneurysm and/or aortic valve disease were studied in this retrospective cross-sectional study. Aortic dilatation was defined as an aortic root or ascending aortic diameter ≥45 mm. Medications were self-reported by the patients in a systematic questionnaire. Cyclooxygenase gene expression was measured in the intima-media portion of the ascending aorta (n=117). In a multivariable analysis, ASA was associated with a reduced prevalence of ascending aortic aneurysm (relative risk, 0.68 [95% CI, 0.48-0.95], P=0.026) in patients with tricuspid aortic valves, but not in patients with bicuspid aortic valves (relative risk, 0.93 [95% CI, 0.64-1.34], P=0.687). Intima-media cyclooxygenase expression was positively correlated with ascending aortic dimensions (P<0.001 for cyclooxygenase-1 and P=0.05 for cyclooxygenase-2). In dilated, but not nondilated tricuspid aortic valve aortic specimens, ASA was associated with significantly lower cyclooxygenase-2 levels (P=0.034). Conclusions Our findings are consistent with the hypothesis that ASA treatment may attenuate ascending aortic aneurysmal growth, possibly via cyclooxygenase-2 inhibition in the ascending aortic wall and subsequent anti-inflammatory actions.

Overcoming Therapy Resistance in Colon Cancer by Drug Repurposing

Simple Summary

Despite improvements in standardized screening methods and the development of promising therapies for colorectal cancer (CRC), survival rates are still low. Drug repurposing offers an affordable solution to achieve new indications for previously approved drugs that could play a protagonist or adjuvant role in the treatment of CRC. In this review, we summarize the current data supporting drug repurposing as a feasible option for patients with CRC.

Abstract

Colorectal cancer (CRC) is the third most common cancer in the world. Despite improvement in standardized screening methods and the development of promising therapies, the 5-year survival rates are as low as 10% in the metastatic setting. The increasing life expectancy of the general population, higher rates of obesity, poor diet, and comorbidities contribute to the increasing trends in incidence. Drug repurposing offers an affordable solution to achieve new indications for previously approved drugs that could play a protagonist or adjuvant role in the treatment of CRC with the advantage of treating underlying comorbidities and decreasing chemotherapy toxicity. This review elaborates on the current data that supports drug repurposing as a feasible option for patients with CRC with a focus on the evidence and mechanism of action promising repurposed candidates that are widely used, including but not limited to anti-malarial, anti-helminthic, anti-inflammatory, anti-hypertensive, anti-hyperlipidemic, and anti-diabetic agents.

Synthesis of 5,7-diarylindoles via Suzuki-Miyaura coupling in water

The synthesis of novel 5,7-diaryl and diheteroaryl indoles has been explored via efficient double Suzuki-Miyaura coupling. The method notably employs a low catalyst loading of Pd(PPh₃)₄ (1.5 mol%/coupling) and water as the reaction solvent to obtain 5,7-diarylated indoles without using N-protecting groups in up to 91% yield. The approach is also suitable for N-protected and 3-substituted indoles and constitutes an important green and convenient arylation strategy for the benzenoid ring of indoles. The synthesized diarylindoles are fluorescent.

Utility of novel 2-furanones in synthesis of other heterocyclic compounds having anti-inflammatory activity with dual COX2/LOX inhibition

Inflammation is associated with the development of several diseases comprising cancer and cardiovascular disease. Agents that suppress cyclooxygenase (COX) and lipoxygenase (LOX) enzymes, besides chemokines have been suggested to minimise inflammation. Here, a variety of novel heterocyclic and non-heterocyclic compounds were prepared from novel three furanone derivatives. The structures of all synthesised compounds were confirmed by elemental and spectral analysis including mass, IR, and ¹H-NMR spectroscopy. Anti-inflammatory activities of these synthesised compounds were examined in vitro against COX enzymes, 15-LOX, and tumour necrosis factor-α (TNF-α), using inhibition screening assays. The majority of these derivatives showed significant to high activities, with three pyridazinone derivatives (5b, 8b, and 8c) being the most promising anti-inflammatory agents with dual COX-2/15-LOX inhibition activities along with high TNF-α inhibition activity.

Efficacy of an opioid-sparing analgesic protocol in pain control after less invasive cranial neurosurgery

An opioid-sparing protocol for postoperative pain management in less invasive cranial neurosurgery significantly lowered opioid usage while reducing pain scores.

Introduction:

Opioid overuse in postoperative patients is a worrisome trend, and potential alternatives exist which warrant investigation. Nonsteroidal anti-inflammatory drug use in treating postoperative cranial surgery pain has been hampered by concern for inadequate pain control and increased risk of hemorrhagic complications. A safe and effective alternative to opioid-based pain management is critical to improving postoperative care.

Objective:

The objective of this retrospective study was to determine whether an NSAID-based opioid-sparing pain management protocol (OSP) is effective in analgesic control of less invasive cranial surgery patients at 6-, 12-, and 24-hour postoperatively. Secondary aims included investigating differences in hemorrhagic complications.

Methods:

Five hundred sixty-six consecutive patients who underwent cranial surgery before and after implementation of the celecoxib-based OSP were eligible. Propensity score matching was used to match patients in each cohort.

Results:

The opioid-sparing cohort had lower pain scores at 6 hours (3.45 vs 4.19, P = 0.036), 12 hours (3.21 vs 4.00, P = 0.006), and 24 hours (2.90 vs 3.59, P = 0.010). Rates of postoperative hemorrhage were not significantly different (5% intervention vs 8% control, P = 0.527). The opioid-sparing pain management protocol provided comparable or better pain control in the first 24 hours after less invasive cranial surgery. Hemorrhage rates did not change with the use of an NSAID-based OSP.

Conclusion:

An effective alternative to the current standard opioid-based pain management is feasible for less invasive cranial surgery. Determinations of hemorrhage risk and more complex cranial surgery will require larger prospective randomized trials.

Antioxidants and/or fish oil reduce intermittent hypoxia-induced inflammation in the neonatal rat terminal ileum

Intermittent hypoxia (IH) is associated with the pathogenesis of necrotizing enterocolitis (NEC). We tested the hypothesis that early supplementation with antioxidants and/or fish oil protects the terminal ileum from oxidative injury induced by neonatal IH. Newborn rats were exposed to neonatal IH from birth (P0) until P14 during which they received daily fish oil, coenzyme Q10 (CoQ10), glutathione nanoparticles (nGSH), fish oil + CoQ10, or olive oil. Pups were then placed in room air from P14 to P21 with no further supplementation. Terminal ileum was assessed for IH-induced injury and inflammatory biomarkers. Neonatal IH induced severe damage consistent with NEC, and was associated with oxidative stress and elevations in PGE2, PGF2α, TxB2, NOS-2 and TLR-4, effects that were ameliorated with nGSH and combination CoQ10+fish oil. Early postnatal supplementation with antioxidants and/or fish oil during neonatal IH may be favorable for preserving gut integrity and reducing oxidative injury.

Low-dose Aspirin prevents hypertension and cardiac fibrosis when thromboxane A2 is unrestrained

Enhanced platelet activation has been reported in patients with essential hypertension and heart failure. The possible contribution of platelet-derived thromboxane (TX)A2 in their pathophysiology remains unclear. We investigated the systemic TXA2 biosynthesis in vivo and gene expression of its receptor TP in 22 essential hypertension patients and a mouse model of salt-sensitive hypertension. The contribution of platelet TXA2 biosynthesis on enhanced blood pressure (BP) and overload-induced cardiac fibrosis was explored in mice by treating with low-dose Aspirin, resulting in selective inhibition of platelet cyclooxygenase (COX)-1-dependent TXA2 generation. In essential hypertensive patients, systemic biosynthesis of TXA2 [assessed by measuring its urinary metabolites (TXM) reflecting predominant platelet source] was enhanced together with higher gene expression of circulating leukocyte TP and TGF-β, vs. normotensive controls. Similarly, in hypertensive mice with prostacyclin (PGI2) receptor (IP) deletion (IPKO) fed with a high-salt diet, enhanced urinary TXM, and left ventricular TP overexpression were detected vs. normotensive wildtype (WT) mice. Increased cardiac collagen deposition and profibrotic gene expression (including TGF-β) was found. Low-dose Aspirin administration caused a selective inhibition of platelet TXA2 biosynthesis and mitigated enhanced blood pressure, cardiac fibrosis, and left ventricular profibrotic gene expression in IPKO but not WT mice. Moreover, the number of myofibroblasts and extravasated platelets in the heart was reduced. In cocultures of human platelets and myofibroblasts, platelet TXA2 induced profibrotic gene expression, including TGF-β1. In conclusion, our results support tailoring low-dose Aspirin treatment in hypertensive patients with unconstrained TXA2/TP pathway to reduce blood pressure and prevent early cardiac fibrosis.

Novel treatments for chronic pain: moving beyond opioids

It is essential that safe and effective treatment options be available to patients suffering from chronic pain. The emergence of an opioid epidemic has shaped public opinions and created stigmas surrounding the use of opioids for the management of pain. This reality, coupled with high risk of adverse effects from chronic opioid use, has led chronic pain patients and their healthcare providers to utilize nonopioid treatment approaches. In this review, we will explore a number of cellular reorganizations that are associated with the development and progression of chronic pain. We will also discuss the safety and efficacy of opioid and nonopioid treatment options for chronic pain. Finally, we will review the evidence for adenylyl cyclase type 1 (AC1) as a novel target for the treatment of chronic pain.

Coagulation and Fibrinolysis in Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) is a common disease which is characterised by repetitive collapse of the upper airways during sleep resulting in chronic intermittent hypoxaemia and frequent microarousals, consequently leading to sympathetic overflow, enhanced oxidative stress, systemic inflammation, and metabolic disturbances. OSA is associated with increased risk for cardiovascular morbidity and mortality, and accelerated coagulation, platelet activation, and impaired fibrinolysis serve the link between OSA and cardiovascular disease. In this article we briefly describe physiological coagulation and fibrinolysis focusing on processes which could be altered in OSA. Then, we discuss how OSA-associated disturbances, such as hypoxaemia, sympathetic system activation, and systemic inflammation, affect these processes. Finally, we critically review the literature on OSA-related changes in markers of coagulation and fibrinolysis, discuss potential reasons for discrepancies, and comment on the clinical implications and future research needs.

Interplay between platelets and coagulation

Haemostasis stops bleeding at the site of vascular injury and maintains the integrity of blood vessels through clot formation. This regulated physiological process consists of complex interactions between endothelial cells, platelets, von Willebrand factor and coagulation factors. Haemostasis is initiated by a damaged vessel wall, followed with a rapid adhesion, activation and aggregation of platelets to the exposed subendothelial extracellular matrix. At the same time, coagulation factors aggregate on the procoagulant surface of activated platelets to consolidate the platelet plug by forming a mesh of cross-linked fibrin. Platelets and coagulation mutually influence each other and there are strong indications that, thanks to the interplay between platelets and coagulation, haemostasis is far more effective than the two processes separately. Clinically this is relevant because impaired interaction between platelets and coagulation may result in bleeding complications, while excessive platelet-coagulation interaction induces a high thrombotic risk. In this review, platelets, coagulation factors and the complex interaction between them will be discussed in detail.

Metabolism pathways of arachidonic acids: mechanisms and potential therapeutic targets

The arachidonic acid (AA) pathway plays a key role in cardiovascular biology, carcinogenesis, and many inflammatory diseases, such as asthma, arthritis, etc. Esterified AA on the inner surface of the cell membrane is hydrolyzed to its free form by phospholipase A2 (PLA2), which is in turn further metabolized by cyclooxygenases (COXs) and lipoxygenases (LOXs) and cytochrome P450 (CYP) enzymes to a spectrum of bioactive mediators that includes prostanoids, leukotrienes (LTs), epoxyeicosatrienoic acids (EETs), dihydroxyeicosatetraenoic acid (diHETEs), eicosatetraenoic acids (ETEs), and lipoxins (LXs). Many of the latter mediators are considered to be novel preventive and therapeutic targets for cardiovascular diseases (CVD), cancers, and inflammatory diseases. This review sets out to summarize the physiological and pathophysiological importance of the AA metabolizing pathways and outline the molecular mechanisms underlying the actions of AA related to its three main metabolic pathways in CVD and cancer progression will provide valuable insight for developing new therapeutic drugs for CVD and anti-cancer agents such as inhibitors of EETs or 2J2. Thus, we herein present a synopsis of AA metabolism in human health, cardiovascular and cancer biology, and the signaling pathways involved in these processes. To explore the role of the AA metabolism and potential therapies, we also introduce the current newly clinical studies targeting AA metabolisms in the different disease conditions.

Clinical benefit of COX-2 inhibitors in the adjuvant chemotherapy of advanced non-small cell lung cancer: A systematic review and meta-analysis

BACKGROUND

Lung cancer is a major cause of death among patients, and non-small cell lung cancer (NSCLC) accounts for more than 80% of all lung cancers in many countries.

AIM

To evaluate the clinical benefit (CB) of COX-2 inhibitors in patients with advanced NSCLC using systematic review.

METHODS

We searched the six electronic databases up until December 9, 2019 for studies that examined the efficacy and safety of the addition of COX-2 inhibitors to chemotherapy for NSCLC. Overall survival (OS), progression free survival (PFS), 1-year survival rate (SR), overall response rate (ORR), CB, complete response (CR), partial response (PR), stable disease (SD), and toxicities were measured with more than one outcome as their endpoints. Fixed and random effects models were used to calculate risk estimates in a meta-analysis. Potential publication bias was calculated using Egger’s linear regression test. Data analysis was performed using R software.

RESULTS

The COX-2 inhibitors combined with chemotherapy were not found to be more effective than chemotherapy alone in OS, progression free survival, 1-year SR, CB, CR, and SD. However, there was a difference in overall response rate for patients with advanced NSCLC. In a subgroup analysis, significantly increased ORR results were found for celecoxib, rofecoxib, first-line treatment, and PR. For adverse events, the increase in COX-2 inhibitor was positively correlated with the increase in grade 3 and 4 toxicity of leukopenia, thrombocytopenia, and cardiovascular events.

CONCLUSION

COX-2 inhibitor combined with chemotherapy increased the total effective rate of advanced NSCLC with the possible increased risk of blood toxicity and cardiovascular events and had no effect on survival index.

The key contribution of platelet and vascular arachidonic acid metabolism to the pathophysiology of atherothrombosis

Arachidonic acid is one of the most abundant and ubiquitous ω-6 polyunsaturated fatty acid, present in esterified form in the membrane phospholipids of all mammalian cells and released from phospholipids by several phospholipases in response to various activating or inhibitory stimuli. Arachidonic acid is the precursor of a large number of enzymatically and non-enzymatically derived, biologically active autacoids, including prostaglandins (PGs), thromboxane (TX) A2, leukotrienes, and epoxyeicosatetraenoic acids (collectively called eicosanoids), endocannabinoids and isoprostanes, respectively. Eicosanoids are local modulators of the physiological functions and pathophysiological roles of blood vessels and platelets. For example, the importance of cyclooxygenase (COX)-1-derived TXA2 from activated platelets in contributing to primary haemostasis and atherothrombosis is demonstrated in animal and human models by the bleeding complications and cardioprotective effects associated with low-dose aspirin, a selective inhibitor of platelet COX-1. The relevance of vascular COX-2-derived prostacyclin (PGI2) in endothelial thromboresistance and atheroprotection is clearly shown by animal and human models and by the adverse cardiovascular effects exerted by COX-2 inhibitors in humans. A vast array of arachidonic acid-transforming enzymes, downstream synthases and isomerases, transmembrane receptors, and specificity in their tissue expression make arachidonic acid metabolism a fine-tuning system of vascular health and disease. Its pharmacological regulation is central in human cardiovascular diseases, as demonstrated by biochemical measurements and intervention trials.

Etoricoxib treatment prevented body weight gain and ameliorated oxidative stress in the liver of high-fat diet-fed rats

The main focus of this study was to determine the role of etoricoxib in counterbalancing the oxidative stress, metabolic disturbances, and inflammation in high-fat (HF) diet-induced obese rats. To conduct this study, 28 male Wistar rats (weighing 190-210 g) were distributed randomly into four groups: control, control + etoricoxib, HF, and HF + etoricoxib. After 8 weeks of treatment with etoricoxib (200 mg/kg), all the animals were sacrificed followed by the collection of blood and tissue samples in order to perform biochemical tests along with histological staining on hepatic tissues. According to this study, etoricoxib treatment prevented the body weight gain in HF diet-fed rats. Furthermore, rats of HF + etoricoxib group exhibited better blood glucose tolerance than the rats of HF diet-fed group. In addition, etoricoxib also markedly normalized HF diet-mediated rise of hepatic enzyme activity. Etoricoxib treatment lowered the level of oxidative stress indicators significantly with a parallel augmentation of antioxidant enzyme activities. Furthermore, etoricoxib administration helped in preventing inflammatory cell invasion, collagen accumulation, and fibrotic catastrophe in HF diet-fed rats. The findings of the present work are suggestive of the helpful role of etoricoxib in deterring the metabolic syndrome as well as other deleterious pathological changes afflicting the HF diet-fed rats.

The Role(s) of Eicosanoids and Exosomes in Human Parturition

The roles that eicosanoids play during pregnancy and parturition are crucial to a successful outcome. A better understanding of the regulation of eicosanoid production and the roles played by the various end products during pregnancy and parturition has led to our view that accurate measurements of a panel of those end products has exciting potential as diagnostics and prognostics of preterm labor and delivery. Exosomes and their contents represent an exciting new area for research of movement of key biological factors circulating between tissues and organs akin to a parallel endocrine system but involving key intracellular mediators. Eicosanoids and enzymes regulating their biosynthesis and metabolism as well as regulatory microRNAs have been identified within exosomes. In this review, the regulation of eicosanoid production, abundance and actions during pregnancy will be explored. Additionally, the functional significance of placental exosomes will be discussed.

Multifaceted Functions of Platelets in Cancer: From Tumorigenesis to Liquid Biopsy Tool and Drug Delivery System

Platelets contribute to several types of cancer through plenty of mechanisms. Upon activation, platelets release many molecules, including growth and angiogenic factors, lipids, and extracellular vesicles, and activate numerous cell types, including vascular and immune cells, fibroblasts, and cancer cells. Hence, platelets are a crucial component of cell-cell communication. In particular, their interaction with cancer cells can enhance their malignancy and facilitate the invasion and colonization of distant organs. These findings suggest the use of antiplatelet agents to restrain cancer development and progression. Another peculiarity of platelets is their capability to uptake proteins and transcripts from the circulation. Thus, cancer-patient platelets show specific proteomic and transcriptomic expression patterns, a phenomenon called tumor-educated platelets (TEP). The transcriptomic/proteomic profile of platelets can provide information for the early detection of cancer and disease monitoring. Platelet ability to interact with tumor cells and transfer their molecular cargo has been exploited to design platelet-mediated drug delivery systems to enhance the efficacy and reduce toxicity often associated with traditional chemotherapy. Platelets are extraordinary cells with many functions whose exploitation will improve cancer diagnosis and treatment.

Cytokinesis-block micronucleus assay of celecoxib and celecoxib derivatives

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New derivatives of celecoxib can improve beneficial effects with better safety profile.

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DNA damage in form of micronuclei has not been observed after treatment with celecoxib or any derivative.

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Further development of celecoxib derivatives for chemoprevention may be promising.

Celecoxib is used widely for the acute treatment of pain and for pain relief in various diseases. Furthermore, it shows potential in chemoprevention, although chronic treatment with celecoxib could lead to adverse effects like cardiovascular events. New derivatives of celecoxib were synthesised that may be suitable as chemopreventive agent without inducing adverse effects.

Critical endpoint for a safe use of pharmaceuticals is genotoxicity after application. A standard test for the assessment of genotoxicity is the cytokinesis-block micronucleus assay, that evaluates the number micronuclei after treatment of cells with a test compound as biomarker for DNA damage. Various promising derivatives of celecoxib have been assessed with the cytokinesis-block micronucleus assay in HeLa-H2B-GFP cells. It could be demonstrated, that neither celecoxib nor its derivatives were genotoxic in this assay and therefore celecoxib derivatives could be developed further for a safe use as chemopreventive agent.

Combating Inflammation in Cardiovascular Disease

The role of inflammation in promoting atherosclerosis and subsequent cardiovascular disease is increasingly recognised, particularly after the publication of Anti-inflammatory Therapy with Canakinumab for Atherosclerotic Disease (CANTOS) and Colchicine Cardiovascular Outcomes (COLCOT) trials. It appears that specifically targeting the Nod-like receptor protein 3 (NLRP3) inflammasome-interleukin 1/interleukin 18-interleukin 6 pathway appears to be most beneficial in cardiovascular risk reduction. High sensitivity C-reactive protein (CRP) is a downstream biomarker of inflammation that can be used to monitor treatment. This article will discuss the role of inflammation in cardiovascular disease, the utility of high sensitivity C-reactive protein and treatments that target this inflammation. While further research is needed into the cost effectiveness and safety of newer agents, it remains an evolving approach to manage cardiovascular risk.

International Union of Basic and Clinical Pharmacology. CIX. Differences and Similarities between Human and Rodent Prostaglandin E2 Receptors (EP1-4) and Prostacyclin Receptor (IP): Specific Roles in Pathophysiologic Conditions

Prostaglandins are derived from arachidonic acid metabolism through cyclooxygenase activities. Among prostaglandins (PGs), prostacyclin (PGI2) and PGE2 are strongly involved in the regulation of homeostasis and main physiologic functions. In addition, the synthesis of these two prostaglandins is significantly increased during inflammation. PGI2 and PGE2 exert their biologic actions by binding to their respective receptors, namely prostacyclin receptor (IP) and prostaglandin E2 receptor (EP) 1-4, which belong to the family of G-protein-coupled receptors. IP and EP1-4 receptors are widely distributed in the body and thus play various physiologic and pathophysiologic roles. In this review, we discuss the recent advances in studies using pharmacological approaches, genetically modified animals, and genome-wide association studies regarding the roles of IP and EP1-4 receptors in the immune, cardiovascular, nervous, gastrointestinal, respiratory, genitourinary, and musculoskeletal systems. In particular, we highlight similarities and differences between human and rodents in terms of the specific roles of IP and EP1-4 receptors and their downstream signaling pathways, functions, and activities for each biologic system. We also highlight the potential novel therapeutic benefit of targeting IP and EP1-4 receptors in several diseases based on the scientific advances, animal models, and human studies. SIGNIFICANCE STATEMENT: In this review, we present an update of the pathophysiologic role of the prostacyclin receptor, prostaglandin E2 receptor (EP) 1, EP2, EP3, and EP4 receptors when activated by the two main prostaglandins, namely prostacyclin and prostaglandin E2, produced during inflammatory conditions in human and rodents. In addition, this comparison of the published results in each tissue and/or pathology should facilitate the choice of the most appropriate model for the future studies.

Biased signaling in platelet G-protein coupled receptors

Platelets are small megakaryocyte-derived, anucleate, disk-like structures that play an outsized role in human health and disease. Both a decrease in the number of platelets and a variety of platelet function disorders result in petechiae or bleeding that can be life threatening. Conversely, the inappropriate activation of platelets, within diseased blood vessels, remains the leading cause of death and morbidity by affecting heart attacks and stroke. The fine balance of the platelet state in healthy individuals is controlled by a number of receptor-mediated signaling pathways that allow the platelet to rapidly respond and maintain haemostasis. G-protein coupled receptors (GPCRs) are particularly important regulators of platelet function. Here we focus on the major platelet-expressed GPCRs and discuss the roles of downstream signaling pathways (e.g., different G-protein subtypes or β-arrestin) in regulating the different phases of the platelet activation. Further, we consider the potential for selectively targeting signaling pathways that may contribute to platelet responses in disease through development of biased agonists. Such selective targeting of GPCR-mediated signaling pathways by drugs, often referred to as biased signaling, holds promise in delivering therapeutic interventions that do not present significant side effects, especially in finely balanced physiological systems such as platelet activation in haemostasis.

Structural investigation on the selective COX-2 inhibitors mediated cardiotoxicity: A review

Initially, the selective COX-2 inhibitors were developed as safer alternatives to the conventional NSAIDs, but later on, most of them were withdrawn from the market due to the risk of heart attack and stroke. Celecoxib, the first selective COX-2 inhibitor, was approved by the Food and Drug Administration (FDA) in December 1998 and was taken back from the market in 2004. Since then, many coxibs have been discontinued one by one due to adverse cardiovascular events. United States (US), Australian and European authorities related to Therapeutic Goods Administration (TGA) implemented the requirements to carry the "Black box" warning on the labels of COX-2 drugs highlighting the risks of serious cardiovascular events. These facts encouraged the researchers to explore them well and find out the biochemical basis behind the cardiotoxicity. From the last few decades, the molecular mechanisms behind the coxibs have regained the attention, especially the specific structural features of the selective COX-2 inhibitors that are associated with cardiotoxicity. This review discusses the key structural features of the selective COX-2 inhibitors and underlying mechanisms that are responsible for the cardiotoxicity. This report also unfolds different strategies that have been reported in the last 10 years to combat the problem of selective COX-2 inhibitors mediated cardiotoxicity.

Pharmacological Characterization of the Microsomal Prostaglandin E2 Synthase-1 Inhibitor AF3485 In Vitro and In Vivo

Rationale

The development of inhibitors of microsomal prostaglandin (PG)E₂ synthase-1 (mPGES-1) was driven by the promise of attaining antiinflammatory agents with a safe cardiovascular profile because of the possible diversion of the accumulated substrate, PGH₂, towards prostacyclin (PGI₂).

Objectives

We studied the effect of the human mPGES-1 inhibitor, AF3485 (a benzamide derivative) on prostanoid biosynthesis in human whole blood in vitro. To characterize possible off-target effects of the compound, we evaluated: i)the impact of its administration on the systemic biosynthesis of prostanoids in a model of complete Freund's adjuvant (CFA)-induced monoarthritis in rats; ii) the effects on cyclooxygenase (COX)-2 expression and the biosynthesis of prostanoids in human monocytes and human umbilical vein endothelial cells (HUVECs) in vitro.

Methods

Prostanoids were assessed in different cellular models by immunoassays. The effect of the administration of AF3485 (30 and 100 mg/kg,i.p.) or celecoxib (20mg/kg, i.p.), for 3 days, on the urinary levels of enzymatic metabolites of prostanoids, PGE-M, PGI-M, and TX-M were assessed by LC-MS.

Results

In LPS-stimulated whole blood, AF3485 inhibited PGE₂ biosynthesis, in a concentration-dependent fashion. At 100μM, PGE₂ levels were reduced by 66.06 ± 3.30%, associated with a lower extent of TXB₂ inhibition (40.56 ± 5.77%). AF3485 administration to CFA-treated rats significantly reduced PGE-M (P < 0.01) and TX-M (P < 0.05) similar to the selective COX-2 inhibitor, celecoxib. In contrast, AF3485 induced a significant (P < 0.05) increase of urinary PGI-M while it was reduced by celecoxib. In LPS-stimulated human monocytes, AF3485 inhibited PGE₂ biosynthesis with an IC₅₀ value of 3.03 µM (95% CI:0.5–8.75). At 1μM, AF3485 enhanced TXB₂ while at higher concentrations, the drug caused a concentration-dependent inhibition of TXB₂. At 100 μM, maximal inhibition of the two prostanoids was associated with the downregulation of COX-2 protein by 86%. These effects did not involve AMPK pathway activation, IkB stabilization, or PPARγ activation. In HUVEC, AF3485 at 100 μM caused a significant (P < 0.05) induction of COX-2 protein associated with enhanced PGI₂ production. These effects were reversed by the PPARγ antagonist GW9662.

Conclusions

The inhibitor of human mPGES-1 AF3485 is a novel antiinflammatory compound which can also modulate COX-2 induction by inflammatory stimuli. The compound also induces endothelial COX-2-dependent PGI₂ production via PPARγ activation, both in vitro and in vivo, which might translate into a protective effect for the cardiovascular system.

Cardiovascular risk of nonsteroidal anti-inflammatory drugs in dialysis patients: a nationwide population-based study

Background

Given the cardiovascular risk of nonsteroidal anti-inflammatory drugs (NSAIDs), it is essential to identify the relationship between NSAIDs and cardiovascular outcomes in dialysis patients who have elevated cardiovascular risk.

Methods

A case-crossover study was conducted to assess the association of NSAIDs with major adverse cardiac and cerebrovascular events (MACCEs) and mortality using the Korean Health Insurance dataset. The case period was defined as 1–30 days prior to the event date and the control periods were defined as 61–90 days and 91–120 days prior to the event date.

Results

There were 3433 and 8524 incident dialysis patients who experienced MACCEs and mortality, respectively, after exposure to NSAIDs within 120 days before each event. NSAIDs significantly increased the risk of MACCEs {adjusted odds ratio [aOR] 1.37 [95% confidence interval (CI) 1.26–1.50]} and mortality [aOR 1.29 (95% CI 1.22–1.36)]. Nonselective NSAIDs, but not selective cyclooxygenase-2 inhibitors, significantly increased the risk of MACCEs and mortality. However, the MACCE and mortality risk did not increase in a dose-dependent manner in the analysis according to the cumulative defined daily dosage of NSAIDs. The incidence of MACCEs in the case period tended to be more common in patients who had recent exposure to NSAIDs than in patients who did not have recent exposure to NSAIDs.

Conclusions

Clinicians should be particularly cautious when prescribing NSAIDs to dialysis patients considering the associations of NSAIDs with cardiovascular outcomes and mortality, which might occur independent of the dose and duration of exposure.

Action of low doses of Aspirin in Inflammation and Oxidative Stress induced by aβ1-42 on Astrocytes in primary culture

Aspirin has been used as anti-inflammatory and anti-aggregate for decades but the precise mechanism(s) of action after the presence of the toxic peptide Aβ_1-42 in cultured astrocytes remains poorly resolved. Here we use low-doses of aspirin (10^-7 M) in astrocytes in primary culture in presence or absence of Aβ_1-42 toxic peptide. We noted an increase of cell viability and proliferation with or without Aβ_1-42 peptide presence in aspirin treated cells. In addition, a decrease in apoptosis, determined by Caspase 3 activity and the expression of Cyt c and Smac/Diablo, were detected. Also, aspirin diminished necrosis process (LDH levels), pro-inflammatory mediators (IL-β and TNF-α) and NF-ᴋB protein expression, increasing anti-inflammatory PPAR-γ protein expression, preventing Aβ_1-42 toxic effects. Aspirin inhibited COX-2 and iNOS without changes in COX-1 expression, increasing anti-oxidant protein (Cu/Zn-SOD and Mn-SOD) expression in presence or absence of Aβ_1-42. Taken together, our results show that aspirin, at low doses increases cell viability by decreasing inflammation and oxidative stress, preventing the deleterious effects of the Aβ_1-42 peptide on astrocytes in primary culture. The use of low doses of aspirin may be more suitable for Alzheimer's disease.