Clinical endoscopic evaluation of the gastroduodenal tolerance to (R)- ketoprofen, (R)- flurbiprofen, racemic ketoprofen, and paracetamol: a randomized, single-blind, placebo-controlled trial

Conjugation with Tris Decreases the Risk of Ketoprofen-Induced Mucosal Damage and Reduces Inflammation-Associated Methane Production in a Rat Model of Colitis

We have designed a new compound from the non-steroidal anti-inflammatory drug (NSAID) ketoprofen (Ket) and 2-amino-2-(hydroxymethyl)-1,3-propanediol (Tris) precursors, with the aim to reduce the gastrointestinal (GI) side effects of NSAID therapies. We investigated mucosal reactions in a standard rat model of colitis together with methane generation as a possible indicator of pro-inflammatory activation under this condition (approval number: V./148/2013). Whole-body methane production (photoacoustic spectroscopy) and serosal microcirculation (intravital videomicroscopy) were measured, and mucosal damage was assessed (conventional histology; in vivo laser-scanning endomicroscopy). Inflammatory markers were measured from tissue and blood samples. Colitis induced an inflammatory response, morphological colonic damage and increased methane output. Ket treatment lowered inflammatory activation and colonic mucosal injury, but macroscopic gastric bleeding and increased methane output were present. Ket-Tris reduced inflammatory activation, methane emission and colonic mucosal damage, without inducing gastric injury. Conjugation with Tris reduces the GI side effects of Ket and still decreases the inflammatory response in experimental colitis. Methane output correlates with the mucosal inflammatory response and non-invasively demonstrates the effects of anti-inflammatory treatments.

Differential Effects of Nonsteroidal Anti-Inflammatory Drugs in an In Vitro Model of Human Leaky Gut

The intestinal barrier is the main contributor to gut homeostasis. Perturbations of the intestinal epithelium or supporting factors can lead to the development of intestinal hyperpermeability, termed "leaky gut". A leaky gut is characterized by loss of epithelial integrity and reduced function of the gut barrier, and is associated with prolonged use of Non-Steroidal Anti-Inflammatories. The harmful effect of NSAIDs on intestinal and gastric epithelial integrity is considered an adverse effect that is common to all drugs belonging to this class, and it is strictly dependent on NSAID properties to inhibit cyclo-oxygenase enzymes. However, different factors may affect the specific tolerability profile of different members of the same class. The present study aims to compare the effects of distinct classes of NSAIDs, such as ketoprofen (K), Ibuprofen (IBU), and their corresponding lysine (Lys) and, only for ibuprofen, arginine (Arg) salts, using an in vitro model of leaky gut. The results obtained showed inflammatory-induced oxidative stress responses, and related overloads of the ubiquitin-proteasome system (UPS) accompanied by protein oxidation and morphological changes to the intestinal barrier, many of these effects being counteracted by ketoprofen and ketoprofen lysin salt. In addition, this study reports for the first time a specific effect of R-Ketoprofen on the NFkB pathway that sheds new light on previously reported COX-independent effects, and that may account for the observed unexpected protective effect of K on stress-induced damage on the IEB.

A doxycycline-inducible CYP3A4-Caco-2 cell line as a model for evaluating safety of aflatoxin B1 in the human intestine

Exposure of humans to aflatoxin B1 (AFB1) via ingestion of contaminated agricultural products is a major concern for human health throughout the world because epoxidized AFB1, biotransformed from AFB1 by hepatic CYP3A4, is strongly hepatotoxic and hepatocarcinogenic. Intestinal epithelial cells serve as a physical and physiological barrier against xenobiotics via their intercellular tight junction (TJ) seals and the metabolizing enzyme CYP3A4. However, the effect of AFB1 on the intestinal barrier remains unclear. Here, we investigated the influence of AFB1 on these physical and physiological intestinal barriers by means of an in vitro human intestinal model utilizing doxycycline-inducible CYP3A4-expressing Caco-2 cells, in which CYP3A4 activity is comparable to that in the adult human intestine. Cellular toxicity of AFB1 in induced Caco-2 cells (i.e., cells in which expression of CYP3A4 is induced by doxycycline) was approximately 5 times that of uninduced Caco-2 cells. Exposure to 16 µM AFB1 did not decrease the transepithelial electric resistance (TEER; a measure of TJ barrier integrity) in monolayers of uninduced Caco-2 cells to 95.8 % of that in vehicle-treated cells; in contrast, in induced Caco-2 cells, TEER was reduced to 28.8 %. Exposure to 16 µM AFB1 increased paracellular permeation of 4- and 20-kDa dextrans (paracellular permeation markers) through monolayers of induced Caco-2 cells to 5.4 and 5.2 times that through uninduced Caco-2 cells. These results together show that ingested AFB1 can modulate the intestinal barrier, and that inducible CYP3A4-expressing Caco-2 cells are a promising tool for evaluating the safety of food contaminants in the human intestine.

Effects of flurbiprofen on the functional regulation of serotonin transporter and its misfolded mutant

Flurbiprofen, a nonsteroidal anti-inflammatory drug, reportedly exhibits chemical chaperone activity. Herein, we investigated the role of flurbiprofen in regulating serotonin transporter (SERT) function via membrane trafficking. We used COS-7 cells transiently expressing wild-type (WT) SERT or a C-terminus-deleted mutant of SERT (SERTΔCT), a misfolded protein. Flurbiprofen treatment reduced the expression of immaturely glycosylated SERT and enhanced the expression of maturely glycosylated SERT. In addition, we observed increased serotonin uptake in SERT-expressing cells. These results suggest that flurbiprofen modulates SERT function by promoting membrane trafficking. In SERTΔCT-expressing cells, flurbiprofen reduced the protein expression and uptake activity of SERTΔCT. Furthermore, flurbiprofen inhibited the formation of SERTΔCT aggregates. Studies using flurbiprofen enantiomers suggested that these effects of flurbiprofen on SERT were not mediated via cyclooxygenase inhibition. The levels of GRP78/BiP, an endoplasmic reticulum (ER) stress marker, were assessed to elucidate whether flurbiprofen can ameliorate SERTΔCT-induced ER stress. Interestingly, flurbiprofen induced GRP78/BiP expression only under ER stress conditions and not under steady-state conditions. In HRD1 E3 ubiquitin ligase knockdown cells, flurbiprofen affected the ER-associated degradation system. Collectively, the findings suggest that flurbiprofen may function as an inducer of molecular chaperones, in addition to functioning as a chemical chaperone.

R-Flurbiprofen Traps Prostaglandins within Cells by Inhibition of Multidrug Resistance-Associated Protein-4

R-flurbiprofen is the non-COX-inhibiting enantiomer of flurbiprofen and is not converted to S-flurbiprofen in human cells. Nevertheless, it reduces extracellular prostaglandin E₂ (PGE₂) in cancer or immune cell cultures and human extracellular fluid. Here, we show that R-flurbiprofen acts through a dual mechanism: (i) it inhibits the translocation of cPLA_2α to the plasma membrane and thereby curtails the availability of arachidonic acid and (ii) R-flurbiprofen traps PGE₂ inside of the cells by inhibiting multidrug resistance–associated protein 4 (MRP4, ABCC4), which acts as an outward transporter for prostaglandins. Consequently, the effects of R-flurbiprofen were mimicked by RNAi-mediated knockdown of MRP4. Our data show a novel mechanism by which R-flurbiprofen reduces extracellular PGs at physiological concentrations, particularly in cancers with high levels of MRP4, but the mechanism may also contribute to its anti-inflammatory and immune-modulating properties and suggests that it reduces PGs in a site- and context-dependent manner.

Design of alginate-based aerogel for nonsteroidal anti-inflammatory drugs controlled delivery systems using prilling and supercritical-assisted drying

In this study, a novel preparation method for alginate-based aerogels charged with nonsteroidal anti-inflammatory drugs (NSAIDs) was developed using prilling in combination with supercritical fluid technique. Nanoporous carriers were prepared by laminar jet breakup of drug/alginate solutions or suspensions followed by cross-linking in ethanol or aqueous CaCl(2) solutions, water replacement, and supercritical-CO(2) -assisted drying. A substantial drug loss was observed for highly soluble ketoprofen lysinate, whereas encapsulation efficiency was satisfying for slightly soluble ketoprofen. The tandem technique successfully produced almost spherical aerogels (sphericity coefficient 0.97-0.99) in narrow size distribution with reduced particle shrinkage and smooth surface (surface roughness 1.10-1.13); the internal porous texture of the parent hydrogels was preserved and appeared as a network of nanopores with diameters around 200 nm. Drug release profiles were monitored using a pH change method to evaluate the possible application of the aerogels as fast dissolving NSAIDs formulation. Aqueous cross-linking led to aerogels encapsulating ketoprofen in the amorphous form and with an enhanced burst effect in simulated gastric fluid (75% in 30 min), whereas ethanol cross-linking produced aerogels embedding drug in crystal clusters with slower dissolution rate. The system appears an interesting potential carrier for the fast delivery of slightly soluble drugs in the upper gastrointestinal tract.

Chronic treatment with a novel γ-secretase modulator, JNJ-40418677, inhibits amyloid plaque formation in a mouse model of Alzheimer's disease

BACKGROUND AND PURPOSE

γ-Secretase modulators represent a promising therapeutic approach for Alzheimer's disease (AD) because they selectively decrease amyloid β 42 (Aβ42), a particularly neurotoxic Aβ species that accumulates in plaques in the brains of patients with AD. In the present study, we describe the in vitro and in vivo pharmacological properties of a potent novel γ-secretase modulator, 2-(S)-(3,5-bis(4-(trifluoromethyl)phenyl)phenyl)-4-methylpentanoic acid (JNJ-40418677).

EXPERIMENTAL APPROACH

The potency and selectivity of JNJ-40418677 for Aβ reduction was investigated in human neuroblastoma cells, rat primary neurones and after treatment with single oral doses in non-transgenic mouse brains. To evaluate the effect of JNJ-40418677 on plaque formation, Tg2576 mice were treated from 6 until 13 months of age via the diet.

KEY RESULTS

JNJ-40418677 selectively reduced Aβ42 secretion in human neuroblastoma cells and rat primary neurones, but it did not inhibit Notch processing or formation of other amyloid precursor protein cleavage products. Oral treatment of non-transgenic mice with JNJ-40418677 resulted in an excellent brain penetration of the compound and a dose- and time-dependent decrease of brain Aβ42 levels. Chronic treatment of Tg2576 mice with JNJ-40418677 reduced brain Aβ levels, the area occupied by plaques and plaque number in a dose-dependent manner compared with transgenic vehicle-treated mice.

CONCLUSIONS AND IMPLICATIONS

JNJ-40418677 selectively decreased Aβ42 production, showed an excellent brain penetration after oral administration in mice and lowered brain Aβ burden in Tg2576 mice after chronic treatment. JNJ-40418677 therefore warrants further investigation as a potentially effective disease-modifying therapy for AD.

Lack of enantiomeric influence on the brain cytoprotective effect of ibuprofen and flurbiprofen

R(-) enantiomers of the 2-arylpropionic acid derivatives ibuprofen and flurbiprofen weakly inhibit cyclooxygenase (COX) activity. However, a possible cytoprotective effect has been proposed. The aim of the study is to investigate the possible mechanism of this effect. An in vitro hypoxia-reoxygenation model in rat brain slices was used (n=6 rats per group). After reoxygenation, we measured LDH efflux (neuronal death), brain prostaglandin E(2) (PGE(2)) concentration, interleukins (IL)-1β and 10, oxidative and nitrosative stress (lipid peroxides, glutathione, 3-nitrotyrosine, and nitrites/nitrates). Anti-COX activity was measured in human whole blood. Racemic, R(-), and S(+) enantiomers of ibuprofen and flurbiprofen were tested. All compounds had a cytoprotective effect with IC(50) values in the range of 10(-5) M. R(-) enantiomers did not significantly inhibit brain PGE(2). The concentration of IL-1β was reduced by 53.1% by the racemic form, 30.6% by the S(+) and 43.2% by the R(-) enantiomer of ibuprofen. The IL-10 concentration increased significantly only with S(+)-flurbiprofen (33.1%) and R(-)-flurbiprofen (26.1%). Lipid peroxidation was significantly reduced by all three forms of flurbiprofen. Nitrite + nitrate concentrations were reduced by racemic, S(+), and R(-)-flurbiprofen. Peroxynitrite formation (3-nitrotyrosine) was significantly reduced by racemic and S(+)-ibuprofen. COX inhibition is not the main mechanism of cytoprotection for these compounds. Their influence on inflammatory mediators and oxidative and nitrosative stress could account for the potential cytoprotective effect of R(-) enantiomers.

Stereoconfiguration of antiallergic and immunologic drugs

OBJECTIVE

To review the concept of chirality and its current role in the pharmacology of antiallergic, antiasthmatic, and immunologic agents.

DATA SOURCES

Ovid MEDLINE and PubMed databases from 1950 to the present time were searched.

STUDY SELECTION

Articles that described the pharmacology of chiral antiallergic, antiasthmatic, and immunologic medications were used for this review.

RESULTS

Stereoselectivity affects the pharmacologic profiles of medications in different ways from class to class and within the classes. This summary illustrates that enantiomers differ not only in potency in receptor binding and physiologic effects but also in pharmacokinetic parameters such as volume of distribution, plasma protein binding, metabolism, and clearance. Different enantiomers may produce unrelated pharmacologic effects as well. This review summarizes the variety of possible effects that different stereoisomers may produce and further underlines the importance of the purification and in-depth analysis of chiral compounds.

CONCLUSION

Chirality plays an important role in pharmacokinetics and pharmacodynamics of various pharmaceutical agents. The importance of stereoisomeric purity in the pharmacologic industry has increased during the past decade as demonstrated by the increased number of studies that examined the in vivo and in vitro effects produced by changes in stereoconfiguration of pharmaceutical agents. This review highlights such effects in certain frequently used medications used in the treatment of asthma and various allergic and immunologic disorders.

EULAR evidence based recommendations for the management of hip osteoarthritis: report of a task force of the EULAR Standing Committee for International Clinical Studies Including Therapeutics (ESCISIT)

OBJECTIVE

To develop evidence based recommendations for the management of hip osteoarthritis (OA).

METHODS

The multidisciplinary guideline development group comprised 18 rheumatologists, 4 orthopaedic surgeons, and 1 epidemiologist, representing 14 European countries. Each participant contributed up to 10 propositions describing key clinical aspects of hip OA management. Ten final recommendations were agreed using a Delphi consensus approach. Medline, Embase, CINAHL, Cochrane Library, and HTA reports were searched systematically to obtain research evidence for each proposition. Where possible, outcome data for efficacy, adverse effects, and cost effectiveness were abstracted. Effect size, rate ratio, number needed to treat, and incremental cost effectiveness ratio were calculated. The quality of evidence was categorised according to the evidence hierarchy. The strength of recommendation was assessed using the traditional A-D grading scale and a visual analogue scale.

RESULTS

Ten key treatment propositions were generated through three Delphi rounds. They included 21 interventions, such as paracetamol, NSAIDs, symptomatic slow acting disease modifying drugs, opioids, intra-articular steroids, non-pharmacological treatment, total hip replacement, osteotomy, and two general propositions. 461 studies were identified from the literature search for the proposed interventions of efficacy, side effects, and cost effectiveness. Research evidence supported 15 interventions in the treatment of hip OA. Evidence specific for the hip was strikingly lacking. Strength of recommendation varied according to category of research evidence and expert opinion.

CONCLUSION

Ten key recommendations for the treatment of hip OA were developed based on research evidence and expert consensus. The effectiveness and cost effectiveness of these recommendations were evaluated and the strength of recommendation was scored.

Acetaminophen as symptomatic treatment of pain from osteoarthritis

Osteoarthritis is a major public health burden. The incidence of osteoarthritis increases with advancing age. Symptomatic treatments aimed at alleviating the pain and thereby restoring joint function form the basis of the treatment. The chronic course requires long-term treatment with special attention to minimizing the side effects of drugs. Acetaminophen has a good risk/benefit ratio that has prompted international consensus panels to recommend its use as first-line therapy in dosages of up to 4 g/day. This review discusses safety and efficacy data from randomized double-blind trials of acetaminophen used to alleviate pain caused by osteoarthritis.

Does paracetamol (acetaminophen) reduce the pain of osteoarthritis? A meta-analysis of randomised controlled trials

OBJECTIVE

To assess the best available evidence for efficacy of paracetamol (acetaminophen) in the treatment of osteoarthritis (OA).

DESIGN

Systematic review and meta-analysis of randomised controlled trials (RCTs).

DATA SOURCES

Medline, Embase, Scientific Citation Index, CINAHL, Cochrane Library, and conference abstracts in the past 2 years from the British Society for Rheumatology, the European League Against Rheumatism, the American College of Rheumatology, and the Osteoarthritis Research Society International.

SUBJECTS

10 RCTs including 1712 patients with either symptomatic OA of the knee (6 trials) or hip/knee (3 trials) or multiple joints (1 trial).

MAIN OUTCOME MEASURES

(a). effect size (ES) for pain, stiffness, and functional scores from baseline to end point; (b). rate ratio (RR) and number needed to treat for clinical response rate and patient preference for treatment.

RESULTS

Paracetamol was effective in relieving pain due to OA (ES = 0.21, 95% confidence interval (CI) 0.02 to 0.41). Non-steroidal anti-inflammatory drugs (NSAIDs) were better than paracetamol for pain relief (ES = 0.20, 95% CI 0.10 to 0.30). Clinical response rate was higher with NSAIDs than with paracetamol (RR = 1.24, 95% CI 1.08 to 1.41), and the number of patients who preferred NSAIDs was more than twice the number of those preferring paracetamol (RR = 2.46, 95% CI 1.51 to 4.12). NSAIDs were associated with more frequent gastrointestinal discomfort than paracetamol (RR = 1.35, 95% CI 1.05 to 1.75).

CONCLUSION

Paracetamol is an effective agent for pain relief due to OA. Although safer, it is less effective than NSAIDs. For safety reasons paracetamol should be the first line treatment, with NSAIDs reserved for those who do not respond.

Selective inhibition of Abeta42 production by NSAID R-enantiomers

Non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with reduced risk for Alzheimer's disease (AD) and selected NSAIDs racemates suppress beta-amyloid (Abeta) accumulation in vivo and Abeta42 production in vitro. Clinical use of NSAIDs for preventing or treating AD has been hampered by dose-limiting toxicity believed to be due to cyclooxygenase (COX)-inhibition that is reportedly not essential for selective Abeta42 reduction. Profens have racemates and R-enantiomers were supposed to be inactive forms. Here we demonstrate that R-ibuprofen and R-flurbiprofen, with poor COX-inhibiting activity, reduce Abeta42 production by human cells. Although these R-enantiomers inhibit nuclear factor-kappaB (NF-kappaB) activation and NF-kappaB can selectively regulate Abeta42, Abeta42 reduction is not mediated by inhibition of NF-kappaB activation. Because of its efficacy at lowering Abeta42 production and low toxicity profile, R-flurbiprofen is a strong candidate for clinical development.

Confounding by indication in epidemiologic studies of commonly used analgesics

Confounding by indication is a bias frequently encountered in observational epidemiologic studies of drug effects. Because the allocation of treatment in observational studies is not randomized and the indication for treatment may be related to the risk of future health outcomes, the resulting imbalance in the underlying risk profile between treated and comparison groups can generate biased results. Confounding by indication is often present in studies of drugs that are not widely prescribed, because the indications for their use are narrow and not likely to be present in comparison groups; however, this bias is also observed in the study of widely used over-the-counter and prescription drugs, are exemplified by studies of analgesics. In this article we review examples from the published literature to demonstrate how confounding by indication can affect the findings of pharmacoepidemiologic studies relating analgesic use to various health outcomes.

Early clinical trials of chemopreventive and biologic agents: Designs, populations, and endpoints

The optimal design for initial clinical trials of chemopreventive agents for cancer has not been determined. A single design is unlikely to be the model for chemoprevention of cancer, even for prevention of a single subtype of cancer, because of the heterogeneity of drugs under investigation and the variety of biologic effects being targeted. Factors that are important in designing initial clinical trials include the proposed mechanisms of drug action, the ability and types of assays available to detect that activity or pharmacodynamic effect, and the extent of prior clinical experience. In this article, we present a discussion of the factors to be considered in initial activity studies, followed by a specific example of early clinical assessment of a noncytotoxic agent (R-flurbiprofen, E-7869) as a potential chemopreventive agent for prostate cancer.

Prophylaxis and treatment of NSAID-induced gastroduodenal disorders

A significant percentage of patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) experience some type of adverse gastrointestinal symptoms, lesions of the gastroduodenal tract being clinically the most relevant. NSAIDs cause gastrointestinal damage by 2 independent mechanisms: a topical effect, which is pH and pKa related, and a systemic effect mediated by cyclooxygenase (COX) inhibition with a reduction in prostaglandin synthesis. Using endoscopy, gastroduodenal lesions identified include subepithelial haemorrhages, erosions and ulcers. The prevalence of ulceration in NSAID users has been reported as being between 14 and 31% with a 2-fold higher frequency of gastric ulcers compared with duodenal ulcers. Among the strategies used to decrease the risk of ulcer development are: (i) the use of analgesics other than NSAIDs; (ii) use of the lowest possible dosage of NSAID; (iii) the use of a COX-2 selective NSAID; (iv) the use of low doses of corticosteroids instead of NSAIDs; (v) avoidance of concomitant use of NSAIDs and corticosteroids; and (vi) use of preventive therapy. In an attempt to reduce the incidence of NSAID-induced gastrointestinal lesions, the following approaches have been proposed: (i) use of the prostaglandin analogue misoprostol, which is an antiulcer drug which has been proven to be as effective in the prevention of NSAID-induced gastric and duodenal ulcers as in the reduction of serious upper gastrointestinal complications; (ii) histamine H2 receptor antagonists (H2 antagonists), e.g. ranitidine, cimetidine and famotidine, which are useful in the prevention of NSAID-induced duodenal ulcers during long term treatment, but not in the prevention of NSAID-induced gastric ulcers; (iii) proton pump inhibitors, e.g omeprazole, and pantoprazole, whose efficacy in preventing NSAID-associated ulcers has been recently demonstrated; and (iv) barrier agents, e.g. sucralfate, which cannot be recommended as prophylactic agents to prevent NSAID-induced gastropathy. The first step in the treatment of NSAID-associated ulcers lies in a reduction in the dosage of the NSAID or discontinuation of the drug. If NSAID treatment cannot be withdrawn, a proton pump inhibitor appears to be the most effective treatment in healing ulcers, accelerating the slow healing observed with H2 antagonists.

Preclinical enantioselective pharmacology of (R)- and (S)- ketorolac

Many of the nonsteroidal anti-inflammatory drugs (NSAIDs) are marketed as racemic mixtures, composed of (R)- and (S)- enantiomers. Racemic NSAIDs are potent cyclooxygenase (COX) inhibitors only through the action of the (S)- enantiomers, as the (R)- enantiomers do not exhibit COX inhibition. However, the (R)- enantiomer of ketoprofen exhibits potent analgesic activity and minimal ulcerogenic potential. To extend these observations, we examined the (R)- and (S)- enantiomers of RS- ketorolac, (S)- ketorolac exhibited potent COX1 and COX2 enzyme inhibition, whereas (R)- ketorolac was > 100-fold less active on both COX subtypes. Both enantiomers did not affect norepinephrine or serotonin uptake sites, and nitric oxidase or lipoxygenase activities, nor did they demonstrate any affinity for opioid receptors (mu, delta, or kappa). In experimental models, (S)- ketorolac exhibited about 10-fold greater activity than (R)- ketorolac in the murine phenylquinone writhing model. In this model, morphine sulfate was effective at much lower doses, however, and neither (R)- nor (S)- ketorolac showed any morphine-sparing effect. In the rat gait test for analgesia in the foot paw after injection of brewers yeast suspension, neither (R)- nor (S)- ketorolac affected paw volume. However, both provoked changes in gait scores, the (S)- enantiomer being 30-fold more potent than the (R)- enantiomer. A similar reduction was observed with respect to ulcerogenic potential, measured by direct microscopic changes after test conclusion. These findings suggest that (R)- ketorolac may possess analgesic activity that is independent of COX inhibition and may be associated with reduced ulcerogenic potential compared to effects exhibited by (S)- ketorolac.