Anti-inflammatory drugs, cyclooxygenases and other factors

The Role of Prostaglandins in Different Types of Cancer

The prostaglandins constitute a family of lipids of 20 carbon atoms that derive from polyunsaturated fatty acids such as arachidonic acid. Traditionally, prostaglandins have been linked to inflammation, female reproductive cycle, vasodilation, or bronchodilator/bronchoconstriction. Recent studies have highlighted the involvement of these lipids in cancer. In this review, existing information on the prostaglandins associated with different types of cancer and the advances related to the potential use of them in neoplasm therapies have been analyzed. We can conclude that the effect of prostaglandins depends on multiple factors, such as the target tissue, their plasma concentration, and the prostaglandin subtype, among others. Prostaglandin D2 (PGD₂) seems to hinder tumor progression, while prostaglandin E2 (PGE₂) and prostaglandin F2 alpha (PGF_2α) seem to provide greater tumor progression and aggressiveness. However, more studies are needed to determine the role of prostaglandin I2 (PGI₂) and prostaglandin J2 (PGJ₂) in cancer due to the conflicting data obtained. On the other hand, the use of different NSAIDs (non-steroidal anti-inflammatory drugs), especially those selective of COX-2 (cyclooxygenase 2), could have a crucial role in the fight against different neoplasms, either as prophylaxis or as an adjuvant treatment. In addition, multiple targets, related to the action of prostaglandins on the intracellular signaling pathways that are involved in cancer, have been discovered. Thus, in depth research about the prostaglandins involved in different cancer and the different targets modulated by them, as well as their role in the tumor microenvironment and the immune response, is necessary to obtain better therapeutic tools to fight cancer.

Acute pain: a multifaceted challenge - the role of nimesulide

BACKGROUND

This article summarizes the outcome from an international consensus meeting, which took place in Vienna on 4 November 2014.

SCOPE

The aim of the meeting was to provide the state of the art on the pathophysiology and treatment of acute pain with special emphasis on nimesulide, a non-steroidal anti-inflammatory drug (NSAID) indicated for the treatment of acute pain and primary dysmenorrhea. Besides the data on the mechanisms of acute inflammatory pain and on the efficacy and safety of nimesulide in patients affected by different forms of acute pain, the clinical experience of attending experts was discussed based on selected case reports.

RESULTS

The members of this consensus group recognized that nimesulide is a NSAID highly effective in the treatment of several painful situations with an acute inflammatory component including primary dysmenorrhea. Although safety concerns regarding nimesulide have emerged in recent years, both robust new epidemiological data and clinical experience confirm a positive benefit/risk profile of nimesulide in the treatment of several forms of acute pain.

CONCLUSIONS

The members of this international consensus group concluded that nimesulide, when used appropriately, remains a particularly valuable and safe option for the treatment of several conditions characterized by the presence of acute inflammatory pain because of the rapid onset of the analgesic action, and the positive evidence-based benefit/risk profile.

Are there any differences among non-steroidal anti-inflammatory drugs? Focus on nimesulide

Although the efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) as anti-inflammatory, analgesic and antipyretic agents is well established, there is still an open question as to whether their different pharmacokinetic and pharmacodynamic characteristics do have a different clinical impact in treating rheumatology patients. The mechanism related to the anti-inflammatory activity of these drugs is mainly related to the inhibition of the cyclo-oxygenase (COX)-2 isoform, whereas inhibition of COX-1 is associated with the side effects of these drugs. However, some NSAIDs exert their anti-inflammatory and analgesic action by additional mechanisms. The NSAID nimesulide, along with its preferential activity on COX-2 and a short half-life that correlates with a rapid onset of analgesic action, acts also through a variety of COX-independent pathways that contributes to its potent antiinflammatory and analgesic activity. The pathways affected by nimesulide include inhibition of tumour necrosis factor alpha (TNF-α) release, histamine release, reactive oxygen species production and chondrocyte death. Furthermore, the use of nimesulide has been associated with reduced levels of matrix metalloproteases and other biomarkers of joint destruction, suggesting it may have a protective effect against disease progression. Due to its multifactorial mechanism as well as to rapid onset of the analgesic action, nimesulide represents an appealing therapeutic choice for the treatment of rheumatology patients.

The nociceptive and anti-nociceptive effects of bee venom injection and therapy: a double-edged sword

Bee venom injection as a therapy, like many other complementary and alternative medicine approaches, has been used for thousands of years to attempt to alleviate a range of diseases including arthritis. More recently, additional theraupeutic goals have been added to the list of diseases making this a critical time to evaluate the evidence for the beneficial and adverse effects of bee venom injection. Although reports of pain reduction (analgesic and antinociceptive) and anti-inflammatory effects of bee venom injection are accumulating in the literature, it is common knowledge that bee venom stings are painful and produce inflammation. In addition, a significant number of studies have been performed in the past decade highlighting that injection of bee venom and components of bee venom produce significant signs of pain or nociception, inflammation and many effects at multiple levels of immediate, acute and prolonged pain processes. This report reviews the extensive new data regarding the deleterious effects of bee venom injection in people and animals, our current understanding of the responsible underlying mechanisms and critical venom components, and provides a critical evaluation of reports of the beneficial effects of bee venom injection in people and animals and the proposed underlying mechanisms. Although further studies are required to make firm conclusions, therapeutic bee venom injection may be beneficial for some patients, but may also be harmful. This report highlights key patterns of results, critical shortcomings, and essential areas requiring further study.

Novel 2-(4-methylsulfonylphenyl)pyrimidine derivatives as highly potent and specific COX-2 inhibitors

New series of 2-(4-methylsulfonylphenyl) and 2-(4-sulfamoylphenyl)pyrimidines were synthesized and evaluated for their ability to inhibit cyclooxygenase-2 (COX-2). COX-1 and COX-2 inhibitory activity of these compounds was determined using purified enzyme (PE) and human whole blood (HWB) assays. Extensive structure-activity relationship (SAR) work was carried out within these series, and a wide number of potent and specific COX-2 inhibitors were identified (HWB COX-2 IC(50)=2.4-0.3nM and 80- to 780-fold more selective than rofecoxib).

Pharmacologically active natural products in the defence secretion of Palembus ocularis (Tenebrionidae, Coleoptera)

The tenebrioid beetle Palembus ocularis Casey 1891 has been used in the traditional medicine of Central and South America to treat Asthma bronchiale. Palembus ocularis has large pygidial glands filled with defence chemicals. The defence fluid was analysed by GLC and GLC-MS. The main components are quinones, such as hydroquinone, 2-ethylhydroquinone as major and 2-methylhydroquinone as minor metabolite. Furthermore, terpenes, fatty acids and their esters, cholesterol and lactones were discovered, with 1-pentadecene as a major component. Pharmacological experiments were carried out with the defence fluid and isolated compounds in order to find out if a rational base exists for the use in traditional medicine. 5-Lipoxygenase is inhibited by crude extracts and hydroquinone. Moreover, a combination of different hydroquinones was 20-times more effective than individual substances suggesting a synergistic effect. The inhibitory effect could be further increased with addition of 1-pentadecene. Anti-inflammatory activity was determined by HET-CAM. The polar extracts of Palembus ocularis showed anti-inflammatory activity in this system. Pure hydroquinone exhibited a similar activity as crude extracts indicating that it constitutes the active principle. The 5-LOX and HET-CAM-assays provide good evidence that hydroquinones in the defence fluid of Palembus ocularis have anti-inflammatory properties which would explain the traditional use of this beetle to treat asthma.

Modulation of cyclooxygenase-2 on glycine- and glutamate-induced ion currents in rat periaqueductal gray neurons

Cyclooxygenase (COX) is a key enzyme in the conversion of arachidonic acid to prostaglandins. Two isoforms of COX are known: COX-1 and COX-2. In the present study, the modulatory effect of COX-2 on glycine- and glutamate-induced ion currents in periaqueductal gray (PAG) neurons was investigated using the nystatin-perforated patch clamp method. Continuous application of lipopolysaccharides on PAG neurons resulted in increased glycine-induced ion current and decreased glutamate-induced ion current. In contrast, continuous application of celecoxib, selective COX-2 inhibitor, resulted in decreased glycine-induced ion current and increased glutamate-induced ion current. These results demonstrate that COX-2 modulates neuronal activity of PAG, and it can be suggested that COX-2 participates in the regulation of the descending pain control system in the level of PAG neurons.