Comparison of cyclooxygenase-1 and -2 inhibitory activities of various nonsteroidal anti-inflammatory drugs using human platelets and synovial cells

Fatty acid-mediated signaling as a target for developing type 1 diabetes therapies

INTRODUCTION

Type 1 diabetes (T1D) is an autoimmune disease in which pro-inflammatory and cytotoxic signaling drive the death of the insulin-producing β cells. This complex signaling is regulated in part by fatty acids and their bioproducts, making them excellent therapeutic targets.

AREAS COVERED

We provide an overview of the fatty acid actions on β cells by discussing how they can cause lipotoxicity or regulate inflammatory response during insulitis. We also discuss how diet can affect the availability of fatty acids and disease development. Finally, we discuss development avenues that need further exploration.

EXPERT OPINION

Fatty acids, such as hydroxyl fatty acids, ω-3 fatty acids, and their downstream products, are druggable candidates that promote protective signaling. Inhibitors and antagonists of enzymes and receptors of arachidonic acid and free fatty acids, along with their derived metabolites, which cause pro-inflammatory and cytotoxic responses, have the potential to be developed as therapeutic targets also. Further, because diet is the main source of fatty acid intake in humans, balancing protective and pro-inflammatory/cytotoxic fatty acid levels through dietary therapy may have beneficial effects, delaying T1D progression. Therefore, therapeutic interventions targeting fatty acid signaling hold potential as avenues to treat T1D.

Relationships of pain-causing substances with dry skin and effects of zaltoprofen on alleviation of symptoms in arthritis model mice

Skin dryness is a symptom of rheumatoid arthritis (RA). However, the mechanisms through which dry skin is induced in RA are unclear. Accordingly, in this study, we characterized substances related to pruritus and pain and then evaluated whether oral administration of zaltoprofen (ZLT) alleviated the symptom of dry skin induced by RA in model mice. DBA/1JJmsSlc collagen-induced arthritis model mice were treated with ZLT, and transepidermal water loss (TEWL), capacitance, and inflammation-, pruritus-, and pain-related markers were assessed. Our findings demonstrated that arthritis model mice treated with ZLT exhibited suppression of increases in TEWL and decreases in capacitance. Furthermore, ZLT also blocked the increase in mast cell numbers, substance P expression, and cyclo-oxygenase-2 expression in the skin and prevented enhancement of plasma levels of thymic stromal lymphopoietin, tumor necrosis factor-α, interleukin-6, histamine, and bradykinin. No changes in plasma levels of corticosterone or reactive oxygen species or skin levels of glucocorticoid receptor were observed in ZLT-treated arthritis model mice. Overall, these findings suggested that patients with RA may benefit from biopharmacy to alleviate joint symptoms and nonsteroidal anti-inflammatory drugs for pain relief and alleviation of skin symptoms.

Ibuprofen, a Nonsteroidal Anti-Inflammatory Drug, is a Potent Inhibitor of the Human Sweet Taste Receptor

A sweet taste receptor is composed of heterodimeric G-protein-coupled receptors T1R2 and T1R3. Although there are many sweet tastants, only a few compounds have been reported as negative allosteric modulators (NAMs), such as lactisole, its structural derivative 2,4-DP, and gymnemic acid. In this study, candidates for NAMs of the sweet taste receptor were explored, focusing on the structural motif of lactisole. Ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), has an α-methylacetic acid moiety, and this structure is also shared by lactisole and 2,4-DP. When ibuprofen was applied together with 1 mM aspartame to the cells that stably expressed the sweet taste receptor, it inhibited the receptor activity in a dose-dependent manner. The IC50 value of ibuprofen against the human sweet taste receptor was calculated as approximately 12 μM, and it was almost equal to that of 2,4-DP, which is known as the most potent NAM for the receptor to date. On the other hand, when the inhibitory activities of other profens were examined, naproxen also showed relatively potent NAM activity against the receptor. The results from both mutant analysis for the transmembrane domain (TMD) of T1R3 and docking simulation strongly suggest that ibuprofen and naproxen interact with T1R3-TMD, similar to lactisole and 2,4-DP. However, although 2,4-DP and ibuprofen had almost the same inhibitory activities, these activities were acquired by filling different spaces of the ligand pocket of T1R3-TMD; this knowledge could lead to the rational design of a novel NAM against the sweet taste receptor.

Aspirin use and platelet aggregation in ischemic onset-type pediatric moyamoya patients with intractable headaches (moya-ache)

BACKGROUND

NSAIDs (nonsteroidal anti-inflammatory drugs) were administered to patients with ischemic onset-type moyamoya disease who experience headaches, but their therapeutic effect was very poor and resulted in a drop in quality of life (QOL). On the other hand, patients who were administered aspirin initially to prevent transient ischemic attacks (TIA) were observed to have a better QOL with the absence of headaches. Here, we report on patients with ischemic onset-type moyamoya disease experiencing headaches who received aspirin in order to verify its safety and effectiveness.

METHODS

From October 2012 to July 2014, 35 patients (male: 19, female: 16 average age: 10.5 ± 3.9) with ischemic onset-type pediatric moyamoya disease and who were admitted or commuted to hospital and had surgical treatment were evaluated for background, moyamoya staging (Suzuki), presence/absence of TIA, and platelet aggregation activity by adenosine diphosphate (ADP)/collagen turbidity test. The patients were divided into four groups depending on the intensity of headache prior to being administered aspirin, and the Kruskal-Wallis test was carried out for platelet aggregation activity and moyamoya staging. Also, the 4 × 2 χ² test was carried out for the presence/absence of TIA. Next, the items which were significant in these tests were used as independent variables to analyze the risk of headache onset, using logistic regression analysis.

RESULTS

One item with statistical significance was the platelet aggregation test(PAT) value (on collagen) (P < 0.0001). A logistic regression analysis was carried out, using this value as an independent variable and headache intensity-as a dependent variable. As a result, an increase in PAT value by 1 translated into 4.43 times higher risk of the onset of intractable headache, and the onset of intractable headaches was predicted at 58.8% with collagen. The risk of developing a headache decreased as a result of aspirin administration, and the decrease was dependent on the collagen-induced aggregation suppression effect of aspirin. Aspirin was administered in the range of 1.6~9.5 mg/kg/day, and the PAT value decreasing rate was 42.9% on average. One case alone experienced nasal bleeding, and all cases showed an improvement in the intractable headaches.

CONCLUSIONS

In patients with ischemic onset-type pediatric moyamoya disease who experience headaches, the platelet aggregation activity is accelerated, and aspirin administration is effective in alleviating headaches by inhibiting platelet activation, detected by the collagen PAT.

Development and In Vitro-In Vivo Evaluation of a Novel Sustained-Release Loxoprofen Pellet with Double Coating Layer

This study aimed to develop a novel sustained release pellet of loxoprofen sodium (LXP) by coating a dissolution-rate controlling sub-layer containing hydroxypropyl methyl cellulose (HPMC) and citric acid, and a second diffusion-rate controlling layer containing aqueous dispersion of ethyl cellulose (ADEC) on the surface of a LXP conventional pellet, and to compare its performance in vivo with an immediate release tablet (Loxinon^®). A three-level, three-factor Box-Behnken design and the response surface model (RSM) were used to investigate and optimize the effects of the citric acid content in the sub-layer, the sub-layer coating level, and the outer ADEC coating level on the in vitro release profiles of LXP sustained release pellets. The pharmacokinetic studies of the optimal sustained release pellets were performed in fasted beagle dogs using an immediate release tablet as a reference. The results illustrated that both the citric acid (CA) and ADEC as the dissolution- and diffusion-rate controlling materials significantly decreased the drug release rate. The optimal formulation showed a pH-independent drug release in media at pH above 4.5 and a slightly slow release in acid medium. The pharmacokinetic studies revealed that a more stable and prolonged plasma drug concentration profile of the optimal pellets was achieved, with a relative bioavaibility of 87.16% compared with the conventional tablets. This article provided a novel concept of two-step control of the release rate of LXP, which showed a sustained release both in vitro and in vivo.

Single-dose diclofenac in healthy volunteers can cause decrease in renal perfusion measured by functional magnetic resonance imaging

OBJECTIVES

We investigated changes of renal perfusion after topical and oral diclofenac administration in healthy volunteers using functional magnetic resonance imaging (MRI) with arterial spin labelling (ASL).

METHODS

Twenty-four healthy human participants (21-51 years) underwent 1.5T MRI before and 1 h after a single oral dose of diclofenac (50 mg). Twelve of 24 participants underwent an additional MRI examination following 3-day topical diclofenac administration. For renal perfusion imaging, a flow-sensitive alternating inversion-recovery TrueFISP ASL sequence was applied. Plasma concentrations of diclofenac and serum concentrations of thromboxane were determined.

KEY FINDINGS

After oral diclofenac application, large interindividual differences in plasma concentrations were observed (range <3-4604 nm). Topical diclofenac application did not result in relevant systemic diclofenac levels (range 5-75 nm). MRI showed a significant reduction of renal perfusion in individuals with diclofenac levels ≥225 nm (baseline: 347 ± 7 vs diclofenac: 323 ± 8 ml/min/100 g, P < 0.01); no significant differences were observed in participants with diclofenac levels <225 nm. Diclofenac levels correlated negatively with thromboxane B2 levels pointing towards target engagement.

CONCLUSIONS

Single-dose diclofenac caused a decrease in renal perfusion in participants with diclofenac levels ≥225 nm. We demonstrated that even a single dose of diclofenac can impair renal perfusion, which could be detrimental in patients with underlying chronic kidney disease or acute kidney injury.

Cardio-respiratory Events and Inflammatory Response After Primary Immunization in Preterm Infants < 32 Weeks Gestational Age: A Randomized Controlled Study

BACKGROUND

Inflammation may depress respiration in neonates. This study aimed to establish a link between postimmunization inflammation and cardio-respiratory events (CREs).

METHODS

Randomized double-blind controlled study of infants born < 32 weeks gestation receiving the 2 months vaccine, which comprised diphtheria and tetanus toxoids and acellular pertussis adsorbed combined with inactivated poliomyelitis vaccines and Haemophilus b conjugate and the pneumococcal conjugate 10-valent vaccines. Infants were randomized to ibuprofen treatment or a placebo group (n = 28/group). C-reactive protein (CRP) and prostaglandins E2 (PgE2) levels were assessed before and after immunization. CREs were recorded for 72 hours. Heart rate variability was assessed by polysomnography.

RESULTS

In the placebo group, immunization was associated with significantly increased CRP levels and an increase in CRE (8.6 ± 11.1 before versus 14.0 ± 12.8 after), which did not reach statistical significance (P = 0.08), and no change in PgE2. The increase in CRP was correlated with changes in CRE (r = 0.4: P < 0.05). In the ibuprofen group, immunization significantly increased CRP levels but was not associated with change in CRE (6.7 ± 7.7 before versus 6.8 ± 9.7 after) and PgE2 levels. Comparing the groups, variation in CRE (ΔCRE before versus after immunization) was significantly lower in the ibuprofen group (0.1 ± 7.9 versus 5.4 ± 10.0 ΔCRE; P < 0.05).

CONCLUSION

The first immunization of infants born < 32 weeks was associated with an increase in CRP. Ibuprofen treatment significantly attenuated the variation (Δ) in CRE following first immunization in these infants but the current study could not demonstrate an impact on CRP and PgE2 levels. The impact of anti-inflammatory treatment on antigenicity must be evaluated before their clinical use aiming at reducing CRE after immunization in preterm infants.

Influence of nonsteroidal anti-inflammatory drugs on aspirin's antiplatelet effects and suggestion of the most suitable time for administration of both agents without resulting in interaction

Background

Low-dose aspirin irreversibly inhibits platelet cyclooxygenase-1 (COX-1) and suppresses platelet aggregation. It is effective for secondary prevention of cardiovascular events. Because nonsteroidal anti-inflammatory drugs (NSAIDs) reversibly bind with COX-1, the antiplatelet effects of aspirin may be suppressed when NSAIDs are co-administered. This interaction could be avoided by avoiding simultaneous administration; however, the minimum interval that should separate the administration of aspirin and loxoprofen is not well known. In this study, we investigated how to avoid the influence of NSAIDs on the antiplatelet effects of aspirin. An in vitro experiment was performed to investigate the influence of ibuprofen and loxoprofen at various concentrations on aspirin’s antiplatelet action.

Methods

Platelet aggregation and thromboxane B₂ (TXB₂) levels were measured after addition of aspirin only and NSAIDs plus aspirin to platelet-rich plasma. NSAIDs were used at their maximum plasma concentrations, the assumed concentration after 6 h (for loxoprofen only), and the assumed concentration after 12 h of taking one clinical dose. Platelet aggregation threshold index (PATI), defined as the putative stimulus concentration giving 50% aggregation, was calculated as an index of aggregation activity.

Results

PATI decreased in ibuprofen plus aspirin group compared to that in the aspirin only group, regardless of ibuprofen concentration. Furthermore, PATI significantly decreased when aspirin was added after loxoprofen-trans-OH addition at the maximum concentration (4.1 ± 0.1 μg/mL), compared to that in aspirin only group (5.9 ± 0.1 μg/mL). PATI showed no significant difference after addition of loxoprofen at the assumed concentration after 6 h (aspirin only group, 5.0 ± 0.5 μg/mL; loxoprofen-trans-OH plus aspirin group, 4.9 ± 0.4 μg/mL).In addition, TXB₂ concentration tended to decrease with increasing PATI.

Conclusions

It is desirable to avoid ibuprofen co-administration with the usual once-daily low-dose aspirin therapy; however, a 6-h interval between loxoprofen and aspirin could avoid this potential interaction when loxoprofen is taken before aspirin.

Neutrophil migration towards C5a and CXCL8 is prevented by non-steroidal anti-inflammatory drugs via inhibition of different pathways

BACKGROUND AND PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to induce PG-independent anti-inflammatory actions. Here, we investigated the role of three different NSAIDs (naproxen, ibuprofen and oxaprozin) on neutrophil responses to CXCL8 and C5a.

EXPERIMENTAL APPROACH

Human neutrophils were isolated from healthy volunteers by dextran and Ficoll-Hypaque density gradients. Neutrophils were pre-incubated with different concentrations (1-100 µM) of NSAIDs or kinase inhibitors. Neutrophil degranulation into supernatants was tested by elisa and zymography. Neutrophil chemotaxis was determined using Boyden chambers. F-actin polymerization was determined by Alexa-Fluor 488-conjugated phalloidin fluorescent assay. Integrin expression was assessed by flow cytometry. The phosphorylation of intracellular kinases was studied by Western blot.

KEY RESULTS

Pretreatment with NSAIDs did not affect neutrophil degranulation, but inhibited neutrophil migration and polymerization of F-actin, in response to CXCL8 and C5a. Pretreatment with different NSAIDs prevented C5a-induced integrin (CD11b) up-regulation, while only ibuprofen reduced CXCL8-induced CD11b up-regulation. Pre-incubation with naproxen or oxaprozin, but not ibuprofen, inhibited the PI3K/Akt-dependent chemotactic pathways. Both endogenous (released in cell supernatants) or exogenous (added to cell cultures) PGE2 did not affect C5a- or CXCL8-induced activities. Short-term incubation with NSAIDs did not affect neutrophil PGE2 release.

CONCLUSION AND IMPLICATIONS

Treatment with NSAIDs reduced C5a- and CXCL8-induced neutrophil migration and F-actin polymerization via different mechanisms. Inhibition by ibuprofen was associated with integrin down-regulation, while naproxen and oxaprozin blocked the PI3K/Akt pathway. Both NSAID actions were independent of COX inhibition and PGE2 release.

Capsaicin as new orally applicable gastroprotective and therapeutic drug alone or in combination with nonsteroidal anti-inflammatory drugs in healthy human subjects and in patients

BACKGROUND

Capsaicin is a specific compound acting on capsaicin-sensitive afferent nerves.

AIM

Capsaicin was used to study the different events of human gastrointestinal physiology, pathology, and clinical pharmacology, and possible therapeutic approaches to enhance gastrointestinal mucosal defense in healthy human subjects and in patients with various different gastrointestinal disorders as well as its use with nonsteroidal anti-inflammatory drugs (NSAIDs) in healthy subjects and in patients.

MATERIALS AND METHODS

The observations were carried out in 198 healthy human subjects and in 178 patients with different gastrointestinal (GI) diseases (gastritis, erosions, ulcer, polyps, cancer, inflammatory bowel diseases, colorectal polyps, cancers), and in 69 patients with chronic (Helicobacter pylori positive and negative) gastritis (before and after eradication treatment). The gastric secretory responses and their chemical composition, gastric emptying, sugar loading test, gastric transmucosal potential difference (GTPD) with application of capsaicin alone, after ethanol alone and with capsaicin, indomethacin-induced gastric mucosal microbleeding without and with capsaicin were studied. The immunohistochemical examinations of the capsaicin receptor (TRVP1), calcitonin gene- related peptide (CGRP), and substance P (SP) were carried out in gastrointestinal tract, and especially in patients with chronic gastritis (with and without Helicobacter infection, before and after classical eradication treatment). Classical molecular pharmacological methods were applied to study the drugs inhibiting the gastric basal acid output.

RESULTS

Capsaicin decreased the gastric basal output, enhanced the "non-parietal" (buffering) component of gastric secretory responses, and gastric emptying, and the release of glucagon. Capsaicin prevented the indomethacin- and ethanol-induced gastric mucosal damage; meanwhile capsaicin itself enhanced (GTPD). Capsaicin prevented the indomethacin-induced gastric mucosal microbleeding. The expression of TRVP1 and CGRP increased in the gastric mucosa of patients with chronic gastritis (independently of the presence of Helicobacter pylori infection), and the successfully carried out eradication treatment. The human first phase examinations (the application of acetylsalicylic acid (ASA), diclqfenac, and naproxen together with capcaicinoids) (given in doses that stimulate capsaicin-sensitive afferent vagal nerves) showed no change in the pharmacokinetic parameters of ASA and diclofenac and the ASA and diclofenac-induced platelet aggregation.

CONCLUSIONS

Capsaicin represents a new orally applicable gastroprotective agent in healthy human subjects and in patients with different chemical and Helicobacter pylori-induced mucosal damage and in many other diseases requiring treatment with NSAIDs.

A 2013 updated systematic review & meta-analysis of 36 randomized controlled trials; no apparent effects of non steroidal anti-inflammatory agents on the risk of bleeding after tonsillectomy

BACKGROUND

Although the literature suggests that non-steroidal anti-inflammatory drugs (NSAIDs) are effective in controlling post-operative pain in the paediatric population, physicians have been reluctant to utilise these medications after tonsillectomy due to concerns of increased bleeding rates. While many surgeons prescribe opioid analgesics postoperatively, these are associated with a number of potential adverse side-effects including nausea, vomiting, constipation, excessive sedation and respiratory compromise.

OBJECTIVE OF REVIEW

To compare bleeding rates and severity between recipients of NSAIDs versus placebo or opioid analgesics for tonsillectomy.

SEARCH STRATEGY

Two authors independently searched electronic databases including PubMed, OVID, EMBASE and Cochrane Review from inception to July 2012. The keywords used included: Adenotonsillectomy, Tonsillectomy, Analgesia, Bleeding, Perioperative and Postoperative. These were then combined in various combinations with specific NSAIDs.

EVALUATION METHOD

A systematic review and meta-analysis of all randomised control trials comparing bleeding rates and severity between NSAIDs versus placebo or opioids post-tonsillectomy.

RESULTS

A total of 36 studies met our inclusion criteria including 1747 children and 1446 adults. When all of the studies were combined in a meta-analysis using the most severe outcome, there was no increased risk of bleeding in those using NSAIDs after tonsillectomy. Use of NSAIDs in general [1.30 (0.90-1.88)] or in children [1.06 (0.65-1.74)] was not associated with increased risk of bleeding in general, most severe bleeding, secondary haemorrhage, readmission or need of reoperation due to bleeding. Similarly, there was no increased bleeding risk for specific NSAIDs in adults. In the studies looking at paediatric subjects, the overall odds ratio of bleeding was even lower than in the general population and not significant. This result is based on 18 studies, six of which had zero outcomes in either treatment arm. Similar to the general population analysis, there was no significant difference in any of the subanalyses: bleeds treated with reoperation, readmission or bleeds in children that could be managed conservatively. There were also no significant differences in the subanalyses of individual NSAIDs. Similarly, there was no significant difference in rates of bleeding in the subanalysis of studies that gave NSAIDs multiple times, for instance, both before and after surgery.

CONCLUSIONS

These results suggest that NSAIDs can be considered as a safe method of analgesia among children undergoing tonsillectomy.

Single-dose and multiple-dose pharmacokinetics and dose proportionality of intravenous and intramuscular HPβCD-diclofenac (Dyloject) compared with other diclofenac formulations

STUDY OBJECTIVE

To evaluate single- and repeated-dose pharmacokinetics (PK) and dose proportionality of hydroxypropyl-β-cyclodextrin (HPβCD)-diclofenac compared with Voltarol after intravenous (IV) and intramuscular (IM) administration.

DESIGN

Study 1: Single-dose randomized four-way crossover study. Study 2: Multiple-dose randomized three-way crossover study.

SETTING

Clinical research center.

SUBJECTS

Healthy adult volunteers.

INTERVENTION

Study 1: Subjects received HPβCD-diclofenac and Voltarol, IV and IM, with a 5-day washout between treatment periods. Study 2: Subjects received two doses of IV HPβCD-diclofenac and oral Cataflam once every 6 hours for four doses with a 48-hour washout period between treatment periods.

MEASUREMENTS AND MAIN RESULTS

Study 1: IV HPβCD-diclofenac had a higher peak plasma concentration (Cmax ) and earlier time to reach maximum plasma concentration (Tmax ), but equivalent plasma exposure (area under the curve from time zero to t [AUC0-t ]) to IV Voltarol. The geometric mean ratio of HPβCD-diclofenac (IV) to Voltarol (IV) for AUC0-t was 106.27%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IM) for AUC0-t was 110.91%. The geometric mean ratio of HPβCD-diclofenac (IV) to HPβCD-diclofenac (IM) for AUC0-t was 101.25%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IV) for AUC0-t was 104.96%. Study 2: Cmax for diclofenac was 2904 and 6031 ng/ml after the first IV dose of 18.75 and 37.5 mg HPβCD-diclofenac, respectively, and was 3090 and 5617 ng/ml after the fourth dose, indicating no accumulation. Plasma exposures to 18.75 mg (866 ng·hour/ml) and 37.5 mg (1843 ng·hour/ml) IV HPβCD-diclofenac bracketed that of oral Cataflam 50 mg (1473 ng·hour/ml).

CONCLUSIONS

Study 1: Bioavailability in terms of AUC after IV administration was equivalent for HPβCD-diclofenac compared with Voltarol and after IM administration of HPβCD-diclofenac and Voltarol. Bioavailability in terms of AUC after IM administration of HPβCD-diclofenac was equivalent to IV administration of HPβCD-diclofenac and IV administration of Voltarol. Study 2: HPβCD-diclofenac showed dose proportionality after single- and multiple-dose administration and no accumulation of HPβCD-diclofenac. HPβCD-diclofenac was safe and well tolerated following IV and IM administration.

Influence of nonsteroidal anti-inflammatory drugs on the antiplatelet effects of aspirin in rats

Low-dose aspirin acts by irreversibly acetylating internal cyclooxygenase-1 (COX-1) on platelets, thereby suppressing platelet aggregation. Because nonsteroidal anti-inflammatory drugs (NSAIDs) also inhibit COX-1, the antiplatelet effects of aspirin may be suppressed when it is co-administered with NSAIDs. In this study, the influences of ibuprofen, loxoprofen sodium and etodolac on the antiplatelet effects of aspirin were investigated in male Sprague-Dawley (SD) rats. Aspirin and/or NSAIDs were administered orally at single or multiple daily doses. Platelet aggregation (ADP and collagen were added as stimuli) and serum thromboxane B(2) (TXB(2)) concentrations were measured. The maximum inhibitions of aggregation in the aspirin before ibuprofen group were 41.0±7.8% for ADP and 38.7±5.4% for collagen at 6 h after administration; similar values were seen in the aspirin group; however, percent inhibitions in the aspirin before ibuprofen multiple administration group were lower than those in the aspirin group. Thus, the inhibitory effects of daily low-dose aspirin on platelets are competitively inhibited by the prolonged use of multiple daily doses of ibuprofen. In contrast, serum TXB(2) concentrations in all groups were lower than those in the control group (drug-free). This suggests that the relationship between the inhibition of platelet COX-1 and the suppression of platelet aggregation is nonlinear. When aspirin was administered with loxoprofen sodium, similar effects were observed; however, with etodolac, the antiplatelet effects in all groups were equal to those in the aspirin group. Accordingly, if co-administration with NSAIDs is necessary with low-dose aspirin, a selective COX-2 inhibitor, such as etodolac, should be used.

Neuroprotective effects vary across nonsteroidal antiinflammatory drugs in a mouse model of developing excitotoxic brain injury

Glutamate excitotoxicity is among the main cellular mechanisms leading to perinatal insults in human newborns. We used intracerebral injection of the glutamatergic glutamate N-methyl-D-aspartate-receptor agonist ibotenate to produce excitotoxic lesions mimicking the acquired white matter lesions seen in human preterm infants. We evaluated whether nonsteroidal antiinflammatory drugs (NSAIDs) protected against glutamate excitotoxicity. Aspirin (0.01-100 microg/d), indomethacin (0.1-10 microg/d), paracetamol (10-100 microg/d), or NS-398 (12.5 microg/d) was given daily before ibotenate (P1 to P5) or after ibotenate (P5 to P9). Lesion size was measured on Cresyl Violet-stained brain sections collected on P10. None of the drugs tested alone or in combination increased lesion size. Pretreatment with low- or high-dose aspirin and post-treatment with paracetamol or NS-398 protected against white matter lesions, whereas cortical lesions were decreased by pretreatment with low- or high-dose aspirin or post-treatment with NS-398. The corticosteroid betamethasone (0.18 microg/d) was neuroprotective when given before or after ibotenate and this effect was reversed by concomitant aspirin therapy (10 microg/d). In conclusion, perinatal NSAID administration may have beneficial effects on brain injury if appropriately timed.

Etodolac: an overview of a selective COX-2 inhibitor

Etodolac is a non-steroidal anti-inflammatory drug (NSAID) which has been shown to be effective in the treatment of rheumatoid arthritis and osteoarthritis and a selective COX-2 inhibitor in a wide range of clinically relevant assays in direct comparisons with other NSAIDs. Studies have shown etodolac to have no overall suppression of gastric or duodenal prostaglandins and endoscopic analysis with etodolac showed placebo level scores in comparison with ibuprofen, which showed inducement of gastro-intestinal (GI) side effects. This high degree of gastric tolerability was further demonstrated by microbleeding studies. The favourable GI tolerability profile of etodolac has been shown in long-term and large-scale trials and by routine clinical observation. In summary, etodolac is a well established selective COX-2 inhibitor that has been shown not to suppress gastric or duodenal prostaglandins, to have minimal hepatic or renal effects and to have favourable GI tolerability in comparison with ibuprofen.

Oxaprozin-induced apoptosis on CD40 ligand-treated human primary monocytes is associated with the modulation of defined intracellular pathways

The modulation of CD40L activity might represent a promising therapeutic target to reduce monocyte inflammatory functions in chronic diseases, such as rheumatoid arthritis. In the present study, we investigated the possible influence of nonsteroidal anti-inflammatory drugs (NSAIDs) on CD40L-induced monocyte survival. Monocytes were isolated from buffy coats by using Ficoll-Percoll gradients. Monocyte apoptosis was evaluated by fluorescence microscopy on cytopreps stained with acridine orange or using flow cytometry analysis of Annexin-V and Propidium Iodide staining. Akt and NF-κB activation was assessed using western blot. Caspase 3 activity was determined spectrophotometrically. Among different NSAIDs, only oxaprozin dose-dependently increased apoptosis of CD40L-treated monocytes. Oxaprozin pro-apoptotic activity was associated with the inhibition of CD40L-triggered Akt and NF-κB phosphorylation and the activation of caspase 3. In conclusion, our data suggest that oxaprozin-induced apoptosis in CD40L-treated human monocytes is associated with previously unknown cyclooxygenase (COX)-independent pathways. These intracellular proteins might be promising pharmacological targets to increase apoptosis in CD40L-treated monocytes.

Interdisciplinary review for correlation between the plant origin capsaicinoids, non-steroidal antiinflammatory drugs, gastrointestinal mucosal damage and prevention in animals and human beings

BACKGROUND

The plant origin capsaicinoids (capsaicin, dihydrocapsaicin, norcapsaicin, dihydrocapsaicin, homocapsaicin, homodihydrocapsaicin) are well known and used as nutritional additive agents in the every day nutritional practice from the last 9,500 years; however, we had have a very little scientifically based knowledge on their chemistry, physiology and pharmacology in animal observations, and in humans up to the mid-twentieth century. Our knowledge about their chemistry, physiology, pharmacology entered to be scientifically based evidence from the year 1980, dominantly in animal observations. The human observations with capsaicin (capsaicinoids), in terms of good clinical practice, have been started only in the last 10-year period (from 1997) in randomized, prospective, multiclinical studies. The name of "capsaicin" used only in the physiological and pharmacological research both in animal experiments and in human observation. The "capsaicin" (as a "chemically" used natural compound) modifies the so-called capsaicin-sensitive afferent nerves depending on their applied doses.

AIMS

The specific action of capsaicin (capsaicinoids) on sensory afferent nerves modifying gastrointestinal (GI) function (under very specific conditions) offers a possibility for the production of an orally applicable drug or for other drug combinations, which can be used in the human medical therapy. The production of new drug is based on the critical interdisciplinary review of the results obtained with capsaicinoids.

MATERIALS AND METHODS

This paper gives an interdisciplinary and critical overview on the chemical, physiological, pharmacological and toxicological actions of the natural origin capsaicinoids (from the point of drug production) under conditions of acute, subacute and chronic administration in animal experiments and human observations, toxicology, pharmacokinetics). This interdisciplinary review covers the following main chapters: (1) physiological and pharmacological research tool by capsaicin in the animals and human beings, (2) capsaicin research in animals (including the acute, subacute toxicology and chronic toxicology metabolism, genotoxicology), (3) capsaicin observation with capsaicin in human beings.

CONCLUSION

(1) The capsaicin used in the physiological and pharmacological observations (in animals and human beings) chemically represents different chemical compounds, which can be obtained from the plants (paprika, chilli, etc.), (2) capsaicinoids are able to modify the capsaicin-sensitive afferent nerves, which have principle roles in the defence of different organs (including the gastrointestinal tract [against the different chemicals, heat, strech, chemical millieu-induced damage], (3) the application of capsaicin (capsaicinoids) can be repeated for the beneficial effects on the gastrointestinal tract as those in animal experiments. After this interdisciplinary and critical review, this paper demonstrates the well-planned research pathways of the discoveries of capsaicinoids from plant chemistry, via physiology, pharmacology and toxicology in animal experiments and human observations.

Delayed apoptosis of human monocytes exposed to immune complexes is reversed by oxaprozin: role of the Akt/IkappaB kinase/nuclear factor kappaB pathway

BACKGROUND AND PURPOSE

Monocytes-macrophages play a key role in the initiation and persistence of inflammatory reactions. Consequently, these cells represent an attractive therapeutic target for switching off overwhelming inflammatory responses. Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common drugs for the symptomatic treatment of rheumatic diseases. Their effects have been explained on the basis of cyclooxygenase (COX) inhibition. However, some of the actions of these drugs are not related to inhibition of prostaglandin synthesis.

EXPERIMENTAL APPROACH

We examined the effect of oxaprozin on apoptosis of immune complex-activated monocytes in comparison with drugs of the same class, and the signalling pathway that leads activated monocytes exposed to oxaprozin to apoptosis. In particular, we studied the activity of caspase-3, the involvement of IkappaB kinase (IKK)-nuclear factor kappaB (NF-kappaB) system and the activity of X-linked mammalian inhibitor of apoptosis protein (XIAP), Akt and mitogen-activated protein kinase (MAPK) in activated monocytes in the presence of oxaprozin.

KEY RESULTS

Immune complexes caused the inhibition of monocyte apoptosis. Oxaprozin reversed in a dose-dependent manner immune complex-induced survival of monocytes, without affecting the apoptosis of resting cells. Other NSAIDs are ineffective. The activity of oxaprozin was related to inhibition of Akt activation that, in turn, prevented p38 MAPK, IKK and NF-kappaB activation. Consistently, the inhibition of NF-kappaB activation reduced the production of the anti-apoptotic molecule XIAP, leading to uncontrolled activity of caspase 3.

CONCLUSIONS AND IMPLICATIONS

These results suggest that oxaprozin exerts its anti-inflammatory activity also through COX-independent pathways. It is likely that oxaprozin-mediated inhibition of the Akt/IKK/NF-kappaB pathway contributes to its anti-inflammatory properties.

31P magnetic resonance spectroscopy of endothelial cells grown in three-dimensional matrigel constructs as an enabling platform technology: II. The effect of anti-inflammatory drugs on phosphometabolite levels

In the accompanying study, the authors presented phosphometabolite patterns of endothelial cells grown under three-dimensional (3D) conditions using (31)P magnetic resonance spectroscopy (MRS). Here the authors describe the effect of nonsteroidal anti-inflammatory drugs (NSAIDs), using this enabling platform technology, which is relevant for evaluating drug effects in tissue-engineered endothelial constructs. Treatment with indomethacin significantly changed the phosphometabolite fingerprint in this endothelial model, by, respectively, increasing (81%) and decreasing (42%) glycerophosphocholine (GPC) and phosphomonoesters (PM). Furthermore, a safer approach using a NSAID prodrug was also demonstrated in this study with a indomethacin phospholipid-derived prodrug (DP-155). Like the parental drug, DP-155 increased and decreased the levels of GPC and PM by 100% and 20%, respectively. These changes represent useful biomarkers to monitor NSAID effects on endothelized tissue-engineered constructs for the purpose of controlling endothelial cell survival and inflammation upon implantation.

NSAIDs suppress the expression of claudin-2 to promote invasion activity of cancer cells

Non-steroidal anti-inflammatory drugs (NSAIDs) show chemopreventive effects; however, the precise molecular mechanism of these effects is still unclear. On the other hand, the expression of proteins that form tight junctions (TJs) (such as claudins) in clinically isolated tumors is frequently altered relative to normal tissue. We previously reported that NSAIDs upregulate the expression of claudin-4 and that this upregulation contributes to NSAID-dependent inhibition of both migration activity and anchorage-independent growth of cancer cells. In the current study, we have systematically examined the effects of various NSAIDs on the expression of various TJ proteins and have found that NSAIDs specifically and drastically inhibit the expression of claudin-2. Overexpression or suppression of claudin-2 expression caused stimulation or inhibition, respectively, of the invasion and migration activity of cancer cells. Furthermore, NSAIDs inhibited the invasion and migration activity of cancer cells and this inhibition was suppressed by overexpression of claudin-2. In contrast, neither cell growth nor apoptosis induced by lack of anchorage of cancer cells was affected by overexpression or suppression of expression of claudin-2. These results suggest that inhibition of claudin-2 expression by NSAIDs contributes to NSAID-dependent inhibition of invasion of cancer cells in vitro and that it may be involved in the chemopreventive effects of NSAIDs by inhibiting metastasis in vivo.

Changes in platelet function, hemostasis, and prostaglandin expression after treatment with nonsteroidal anti-inflammatory drugs with various cyclooxygenase selectivities in dogs

OBJECTIVE

To determine the effects of nonsteroidal anti-inflammatory drugs of various cyclooxygenase selectivities on hemostasis and prostaglandin expression in dogs.

ANIMALS

8 client-owned dogs with clinical signs of osteoarthritis.

PROCEDURES

Dogs received aspirin (5 mg/kg, PO, q 12 h), carprofen (4 mg/kg, PO, q 24 h), deracoxib (2 mg/kg, PO, q 24 h), and meloxicam (0.1 mg/kg, PO, q 24 h) for 10 days each, with an interval of at least 14 days between treatments. On days 0 and 10, blood was collected for platelet aggregation assays, thrombelastography, and measurement of lipopolysaccharide-stimulated prostaglandin E(2), platelet thromboxane B(2) (TXB(2)), and free serum TXB(2) and 6-keto-prostaglandin F (PGF)-1alpha concentrations.

RESULTS

Platelet aggregation decreased after treatment with aspirin and carprofen, whereas significant changes from baseline were not detected for the other drugs tested. Thrombelastograms obtained after treatment with carprofen revealed decreased maximum amplitude and alpha-angle, suggesting hypocoagulability. Maximum amplitude and coagulation index increased after treatment with deracoxib. Plasma concentrations of prostaglandin E(2) decreased after treatment with carprofen or deracoxib, and platelet TXB(2) production increased after treatment with aspirin. Serum concentrations of the prostacyclin metabolite 6-keto-PGF-1alpha did not change significantly after treatment with any of the drugs, although the ratio of free TXB(2) to 6-keto-PGF-1alpha decreased slightly after treatment with carprofen and increased slightly after treatment with deracoxib.

CONCLUSIONS AND CLINICAL RELEVANCE

At the dosages tested, treatment with meloxicam affected platelet function minimally in dogs with osteoarthritis. Treatment with carprofen decreased clot strength and platelet aggregation. Clot strength was increased after treatment with deracoxib.

Heme Oxygenase-1 Protects Gastric Mucosal Cells against Non-steroidal Anti-inflammatory Drugs

Gastric mucosal cell death by non-steroidal anti-inflammatory drugs (NSAIDs) is suggested to be involved in NSAID-induced gastric lesions. Therefore, cellular factors that suppress this cell death are important for protection of the gastric mucosa from NSAIDs. Heme oxygenase-1 (HO-1) is up-regulated by various stressors and protects cells against stressors. Here, we have examined up-regulation of HO-1 by NSAIDs and the contribution of HO-1 to the protection of gastric mucosal cells against NSAIDs both in vitro and in vivo. In cultured gastric mucosal cells, all NSAIDs tested up-regulated HO-1. In rats, orally administered indomethacin up-regulated HO-1, induced apoptosis, and produced lesions at gastric mucosa. An inhibitor of HO-stimulated NSAID-induced apoptosis in vitro and in vivo and also stimulated NSAID-produced gastric lesions, suggesting that NSAID-induced up-regulation of HO-1 protects the gastric mucosa from NSAID-induced gastric lesions by inhibiting NSAID-induced apoptosis. Indomethacin activated the HO-1 promoter and caused nuclear accumulation of NF-E2-related factor 2 (Nrf2), a transcription factor for the HO-1 gene. Examination of phosphorylation of p38 mitogen-activated protein kinase (MAPK) and experiments with its inhibitor strongly suggest that the nuclear accumulation of Nrf2 and resulting up-regulation of HO-1 by NSAIDs is mediated through NSAID-dependent activation (phosphorylation) of p38 MAPK. This is the first report showing the protective role of HO-1 against irritant-induced gastric lesions.

Use of non-aspirin nonsteroidal antiinflammatory drugs and the risk of cardiovascular events

OBJECTIVE

To review published evidence on the use of nonselective, non-aspirin nonsteroidal antiinflammatory drugs (NANSAIDs) and the risks of cardiovascular events and examine the justification for Food and Drug Administration (FDA) in recommending that a cardiovascular risk warning statement be included in all NANSAIDs' product information inserts.

DATA SOURCES

Peer-reviewed articles in MEDLINE (1966-August 2006) and Current Contents were identified using the key words NSAID, naproxen, ibuprofen, heart diseases, myocardial infarction, and cardiovascular events. Citations from available articles and related FDA Web sites were reviewed for additional references.

STUDY SELECTION AND DATA EXTRACTION

No randomized, placebo-controlled studies have been published evaluating this subject. Epidemiologic evidence published in English was examined. Sixteen relevant studies were identified (5 cohort, 3 nested case-control, 8 case-control).

DATA SYNTHESIS

Six of the 16 studies demonstrated increased risk for one or more NANSAIDs (rate or ORs varied from 1.13 to 3.08). Five studies demonstrated cardioprotective effect for one or more NANSAIDs used (rate or ORs varied from 0.48 to 0.84). None of the other studies demonstrated an association between use of NANSAIDs and risk of cardiovascular events.

CONCLUSIONS

After adjustment of baseline risk factors for cardiovascular events, epidemiologic studies demonstrated conflicting results regarding the risk of cardiovascular events with long-term use of nonselective NANSAIDs. However, considering the large number of patients consuming NANSAIDs and the potential public health impact, until data from long-term, randomized, controlled trials become available, the FDA's recommendation that a warning statement be included in all nonselective NANSAIDs product package inserts is justified.

NSAID zaltoprofen possesses novel anti-nociceptive mechanism through blockage of B2-type bradykinin receptor in nerve endings

Zaltoprofen, a propionic acid derivative of non-steroidal anti-inflammatory drugs (NSAIDs), was shown to have more powerful inhibitory effects to bradykinin (BK)-nociception than other NSAIDs. However, the molecular mechanisms underlying this potent analgesia are not yet fully understood. Here we attempted to clarify the molecular mechanism underlying zaltoprofen-induced analgesia on BK-induced nociception by a novel algogenic-induced paw flexion (APF) test in mice. The intraplantar (i.pl.) injection of zaltoprofen at 1nmol showed strong analgesic action on BK (i.pl.)-induced nociceptive flexor responses, whereas loxoprofen or its active metabolite loxoprofen-SRS did not. Zaltoprofen also inhibited the nociception induced by [Tyr8]-BK, a specific agonist of B2-type BK receptor, but did not affect the nociception by [Lys-des-Arg9]-BK, a specific agonist of B1-type BK receptor. However, zaltoprofen did not affect the substance P-induced nociception, which is mediated by common post-receptor signaling through nociceptive fibers with BK-ones. All these results suggest that NSAID zaltoprofen possesses novel anti-nociceptive mechanism, which inhibits B2-type BK receptor function in nerve endings.

Celecoxib upregulates endoplasmic reticulum chaperones that inhibit celecoxib-induced apoptosis in human gastric cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce apoptosis in cancer cells and this effect is involved in their antitumor activity. We recently demonstrated that NSAIDs upregulate GRP78, an endoplasmic reticulum (ER) chaperone, in gastric mucosal cells in primary culture. In the present study, induction of ER chaperones by NSAIDs and the effect of those chaperones on NSAID-induced apoptosis were examined in human gastric carcinoma cells. Celecoxib, an NSAID, upregulated ER chaperones (GRP78 and its cochaperones ERdj3 and ERdj4) but also C/EBP homologous transcription factor (CHOP), a transcription factor involved in apoptosis. Celecoxib also upregulated GRP78 in xenograft tumors, accompanying with the suppression of tumor growth in nude mice. Celecoxib caused phosphorylation of eukaryotic translation initiation factor 2 kinase (PERK) and eukaryotic initiation factor-2alpha (eIF2alpha) and production of activating transcription factor (ATF)4 mRNA. Suppression of ATF4 expression by small interfering RNA (siRNA) partially inhibited the celecoxib-dependent upregulation of GRP78. Celecoxib increased the intracellular Ca2+ concentration, while 1,2-bis(2-aminophenoxy)ethane-N,N,N'N'-tetraacetic acid, an intracellular Ca2+ chelator, inhibited the upregulation of GRP78 and ATF4. These results suggest that the Ca2+-dependent activation of the PERK-eIF2alpha-ATF4 pathway is involved in the upregulation of ER chaperones by celecoxib. Overexpression of GRP78 partially suppressed the apoptosis and induction of CHOP in the presence of celecoxib and this suppression was stimulated by coexpression of either ERdj3 or ERdj4. On the other hand, suppression of GRP78 expression by siRNA drastically stimulated cellular apoptosis and production of CHOP in the presence of celecoxib. These results show that upregulation of ER chaperones by celecoxib protects cancer cells from celecoxib-induced apoptosis, thus may decrease the potential antitumor activity of celecoxib.

Serum deprivation and re-addition: effects on cyclooxygenase inhibitor sensitivity in cultured glia

A number of drugs were assessed for their ability to inhibit stimulus-evoked prostanoid synthesis in cultured glia. These drugs included non-selective cyclooxygenase (COX) inhibitors and those considered to be selective for the inducible isoform of this enzyme (COX-2). Experiments were carried out on normal cultures and those which had been maintained in serum-free growth medium for four days then re-exposed to serum for a further seven days. All of the drugs tested elicited concentration-dependent inhibitions of arachidonic acid (AA)-stimulated thromboxane B(2) (TXB(2)) accumulation in normal cultures with the following rank order of potency: indomethacin > piroxicam > nimesulide = NS398 > ibuprofen >> aspirin > paracetamol. In cultures which had been deprived of serum for four days, basal and AA-stimulated TXB(2) production was considerably reduced, as was the amount of COX immunoreactivity determined by Western blotting. Basal and AA-stimulated TXB(2) production together with COX immunoreactivity were restored to control levels by the re-addition of serum to serum-deprived cultures for 7 days. In these cultures, the rank order of potency was: indomethacin > piroxicam >> ibuprofen > nimesulide = NS398 >> aspirin > paracetamol; however, there were marked charges in the apparent IC(50) values for particular drugs. Indomethacin, piroxicam and aspirin were very similar to control, but the potencies of ibuprofen (3-fold), NS398 (30-fold) and nimesulide (40-fold) were found to be decreased when compared to control. Paracetamol, on the other hand, was found to be almost 3-fold more potent under these conditions. Glia appear to express a COX with a novel sensitivity to particular inhibitors following serum deprivation and re-addition.

Prostaglandin E synthase in the pathophysiology of arthritis

Prostaglandin E synthase (PGES) is a recently identified terminal enzyme that acts downstream of cyclooxygenase and catalyzes the conversion of prostaglandin (PG) H2 to PGE2. At least three isozymes have been cloned so far, which are called membrane-associated PGES (mPGES)-1, mPGES-2, and cytosolic PGES. Among them, mPGES-1 is induced by various inflammatory stimuli in some cells and tissues. Induction of mPGES-1 in the component of articular tissues of patients with rheumatoid arthritis and osteoarthritis has been demonstrated in vitro. Recent studies using adjuvant induced arthritis model have shown the increase of mPGES-1 expression resulted in the increase of PGE2 production at the sites of inflammation. In addition, reports of mPGES-1-deficient mice clearly suggest the role of mPGES-1 in the process of chronic inflammation such as collagen-induced arthritis and collagen antibody induced arthritis in vivo. Thus, recent in vitro and in vivo findings suggest that mPGES-1 may be a novel therapeutic target for arthritis. This paper introduces recent advances in research about the role of PGES in the pathophysiology of arthritis.

Prostaglandin E2 production in ovarian cancer cell lines is regulated by cyclooxygenase-1, not cyclooxygenase-2

The significance of cyclooxygenase-2 (COX-2) expression in ovarian cancer has been discussed. In this study, we found increased expression of COX-1 mRNA and protein in three out of 10 ovarian cancer cell lines. Prostaglandin E 2 (PGE2) production was elevated in these three cell lines, but not in other seven cell lines. COX-2 protein was not detected in any of the cell lines. Cytosolic prostaglandin E synthase (cPGES) mRNA and protein were detected in all 10 cell lines. Membrane-associated PGES-1 (mPGES-1) was detected in some of the ovarian cell lines, but its presence did not correspond with PGE2 production. In contrast, mPGES-2 mRNA and protein were detected in all 10 cell lines. A nonselective COX inhibitor (indometacin) and a selective COX-1 inhibitor (SC-560) strongly inhibited PGE2 production by the three cell lines, while selective COX-2 inhibitors (NS-398 and rofecoxib) did not inhibit PGE2 production. In addition, increased expression of COX-1, not COX-2 protein was observed in the mass of ovarian cancer tissues from 22 patients when compared with that in normal tissue. These findings suggest that COX-1 might be a major enzyme regulating PGE2 production in ovarian cancer cells.

Zaltoprofen inhibits bradykinin-induced responses by blocking the activation of second messenger signaling cascades in rat dorsal root ganglion cells

Bradykinin interacts with the bradykinin B2 receptor on dorsal root ganglion (DRG) neurons, setting off a series of reactions inside the cells that ultimately make the vanilloid receptor 1 more sensitive to a normal stimulus by activating various enzymes coupled with second messenger signaling cascades. Zaltoprofen, a propionic acid derivative non-steroidal anti-inflammatory drug (NSAID), was proved to inhibit bradykinin-induced pain responses in vivo experimental systems more potently than indomethacin or other NSAIDs, but the molecular mechanisms underlying its action are not yet fully understood. Currently it appears unlikely that zaltoprofen binds to specific sites on the protein of the bradykinin B2 receptor, hence we have examined the effect of zaltoprofen on bradykinin-induced responses of adult DRG neurons to investigate possible interaction sites. Compared with several other NSAIDs, such as indomethacin, loxoprofen and diclofenac, zaltoprofen most potently inhibits bradykinin-enhancement of capsaicin-induced 45Ca2+ uptake into DRG neurons. Zaltoprofen also significantly inhibits bradykinin-induced 12-lipoxygenase (12-LOX) activity and the slow bradykinin-induced onset of substance P release from DRG neurons. These data indicate zaltoprofen may produce its analgesic effects through the inhibition of bradykinin B2 receptor-mediated bradykinin responses of not only cyclooxygenases (COXs) but also bradykinin induced 12-LOX inhibitors.

A review of the emerging profile of the anti-inflammatory drug oxaprozin

Oxaprozin is a nonsteroidal anti-inflammatory drug characterised by a propionic acid-based structure. It is able to diffuse easily into inflamed synovial tissues after oral administration. Although discovered > 20 years ago, it is now under intensive investigation because of its unusual pharmacodynamic properties. Other than being a nonselective cyclooxygenase inhibitor, the drug is capable of inhibiting both anandamide hydrolase in neurons (median inhibitory concentration [IC50] = 85 micromol/l), with consequent potent analgesic activity, and NF-kappaB activation in inflammatory cells (IC50 = 50 micromol/l). Moreover, oxaprozin induces apoptosis of activated monocytes in a dose-dependent manner, with the effect being detectable at a concentration of 5 micromol/l and reaching the maximum activity at 50 micromol/l. As monocyte-macrophages and NF-kappaB pathways are crucial for synthesis of proinflammatory and histotoxic mediators in inflamed joints, oxaprozin appears to be endowed with pharmacodynamic properties exceeding those presently assumed as markers of classical nonsteroidal anti-inflammatory drug.

A novel celecoxib derivative potently induces apoptosis of human synovial fibroblasts

We have already demonstrated that celecoxib, a selective cyclooxygenase (COX)-2 inhibitor, has a proapoptotic effect on synovial fibroblasts obtained from patients with rheumatoid arthritis (RA). Here we report on the development of two novel derivatives of celecoxib, N-(2-aminoethyl)-4-[5-(4-tolyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide (TT101) and 4-[5-(4-aminophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide (TT201), including whether these compounds have a proapoptotic effect on synovial fibroblasts. Synovial fibroblasts were harvested from the synovial tissues of patients with RA or osteoarthritis (OA). Cell proliferation and cell viability were assessed by the incorporation of 5-bromo-2'-deoxyuridine and by the 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt assay, respectively. Apoptosis was detected by the identification of DNA fragmentation, and activation of caspase-3 was detected by the addition of a caspase-3 substrate to cell lysates. Production of prostaglandin E(2) by RA synovial fibroblasts was analyzed by enzyme-linked immunosorbent assay. TT101 inhibited the proliferation of RA and OA synovial fibroblasts in a concentration-dependent manner. It caused a marked decrease of cell viability and induced DNA fragmentation more potently than either celecoxib or SC-236 (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide). TT101 also increased caspase-3 activity. The order of potency of the COX-2 inhibitory activity of these drugs in RA synovial fibroblasts was celecoxib = SC-236 > rofecoxib > TT201 > TT101. In conclusion, we developed TT101 with about a 5- to 10-fold stronger proapoptotic effect on RA and OA synovial fibroblasts compared with that of celecoxib. Although the mechanism of action of TT101 remains unclear, it may have potential as a novel antirheumatic agent.

Induction of claudin-4 by nonsteroidal anti-inflammatory drugs and its contribution to their chemopreventive effect

Nonsteroidal anti-inflammatory drugs (NSAID) have shown chemopreventive effects in both preclinical and clinical studies; however, the precise molecular mechanism governing this response remains unclear. We used DNA microarray techniques to search for genes whose expression is induced by the NSAID indomethacin in human gastric carcinoma (AGS) cells. Among identified genes, we focused on those related to tight junction function (claudin-4, claudin-1, and occludin), particularly claudin-4. Induction of claudin-4 by indomethacin was confirmed at both mRNA and protein levels. NSAIDs, other than indomethacin (diclofenac and celecoxib), also induced claudin-4. All of the tested NSAIDs increased the intracellular Ca2+ concentration. Other drugs that increased the intracellular Ca2+ concentration (thapsigargin and ionomycin) also induced claudin-4. Furthermore, an intracellular Ca2+ chelator [1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid] inhibited the indomethacin-dependent induction of claudin-4. These results strongly suggest that induction of claudin-4 by indomethacin is mediated through an increase in the intracellular Ca2+ concentration. Overexpression of claudin-4 in AGS cells did not affect cell growth or the induction of apoptosis by indomethacin. On the other hand, addition of indomethacin or overexpression of claudin-4 inhibited cell migration. Colony formation in soft agar was also inhibited. Suppression of claudin-4 expression by small interfering RNA restored the migration activity of AGS cells in the presence of indomethacin. Based on these results, we consider that the induction of claudin-4 and other tight junction-related genes by NSAIDs may be involved in the chemopreventive effect of NSAIDs through the suppression of anchorage-independent growth and cell migration.

Effect of celecoxib, a cyclooxygenase-2 inhibitor, on the pathophysiology of adjuvant arthritis in rat

We investigated the efficacy of celecoxib, a specific cyclooxygenase (COX)-2 inhibitor, on arthritic pathophysiology and confirmed its gastric safety in adjuvant-induced arthritis rats. Results were compared with those for loxoprofen, a non-selective COX inhibitor. Arthritis was induced by injection of 1 mg of Mycobacterium butyricum in 50 microl of liquid paraffin into the left footpad of Lewis rats. The drugs were given by twice daily oral administration for 10 days beginning 15 days after adjuvant injection, with celecoxib at 0.01-3 mg/kg/day and loxoprofen at 0.01-3 mg/kg/day. Celecoxib significantly inhibited paw swelling, hyperalgesic response, and joint destruction (radiographic and histopathological findings) in these arthritic rats. These effects of celecoxib were superior to those of loxoprofen. Further, the administration of loxoprofen (3 mg/kg/day) caused significant gastric lesions, whereas celecoxib at the same dose did not. These results suggest that COX-2-mediated prostaglandins may play an important role in the progression of pathophysiology in this model and that celecoxib may be a useful therapeutic agent for the treatment of rheumatoid arthritis, with greater safety than non-selective COX inhibitors.

Endoplasmic reticulum stress response is involved in nonsteroidal anti-inflammatory drug-induced apoptosis

Apoptosis induced by nonsteroidal anti-inflammatory drugs (NSAIDs) is involved not only in the production of NSAID-induced gastric lesions but also in the antitumor activity of these drugs. The endoplasmic reticulum (ER) stress response is a cellular mechanism that aids in protecting the ER against ER stressors and is involved in ER stressor-induced apoptosis. Here, we examine the relationship between this response and NSAID-induced apoptosis in cultured guinea-pig gastric mucosal cells. Exposure of cells to indomethacin, a commonly used NSAID, induced GRP78 as well as CHOP, a transcription factor involved in apoptosis. Three factors that positively regulate CHOP expression (ATF6, ATF4 and XBP-1) were activated and/or induced by indomethacin. NSAIDs other than indomethacin (diclofenac, ibuprofen and celecoxib) also induced CHOP. Monitoring of the transcriptional activities of ATF6 and CHOP by luciferase assay revealed that both were stimulated in the presence of indomethacin. Furthermore, indomethacin-induced apoptosis was suppressed in cultured guinea-pig gastric mucosal cells by expression of the dominant-negative form of CHOP, or in peritoneal macrophages from CHOP-deficient mice. These results suggest that ER stress response-related proteins, particularly CHOP, are involved in NSAID-induced apoptosis.

Rofecoxib for osteoarthritis

BACKGROUND

Editor's note: The anti-inflammatory drug rofecoxib (Vioxx) was withdrawn from the market at the end of September 2004 after it was shown that long-term use (greater than 18 months) could increase the risk of heart attack and stroke. Further information is available at www.vioxx.com. Osteoarthritis is a chronic disease of the joints, characterised by joint pain, stiffness and loss of physical function. Its onset is age-related and occurs usually between the ages of 50 and 60. It is the commonest cause of disability in those aged over 65, with OA of the knee and/or hip affecting over 20 per cent of the elderly population.

OBJECTIVES

To establish the efficacy and safety of rofecoxib in the management of OA by systematic review of available evidence.

SEARCH STRATEGY

We searched the following databases up to August 2004: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, National Research Register, NHS Economic Evaluation Database, Health Technology Assessment Database. The bibliographies of retrieved papers and content experts were consulted for additional references.

SELECTION CRITERIA

All eligible randomised controlled trials (RCTs) were included. No unpublished RCTs were included in this edition of the review.

DATA COLLECTION AND ANALYSIS

Data were abstracted independently by two reviewers. A validated checklist was used to score the quality of the RCTs. Comparable trials were pooled using fixed effects model.

MAIN RESULTS

Twenty-six RCTs were included. The comparators were placebo, diclofenac, ibuprofen, naproxen, nimesulide, nabumetone, paracetamol, celecoxib and Arthrotec. The evidence reviewed indicated that rofecoxib was more effective than placebo (patient global response RR 1.75 95% CI: 1.35, 2.26) but was associated with more adverse events (RR 1.32 95% CI 1.11, 1.56). There were no consistent differences in efficacy between rofecoxib and any of the active comparators at equivalent doses. Endoscopic studies indicated that compared to ibuprofen 800 mg three times a day, rofecoxib caused fewer erosions and gastric ulcers at doses of 25mg and 50mg; the difference in duodenal ulcers was evident only at a dose of 25mg. Rofecoxib 50mg also caused more endoscopically observed ulcers greater than rofecoxib 25mg (RR 2.48 CI: 1.21, 5.11). Very few of the trials reported overall rates of GI adverse events although rofecoxib was found to cause fewer GI events than naproxen. Only one of the nine trials comparing rofecoxib to celecoxib reported on the overall rates of GI events and this was a comparison of the higher recommended dose of rofecoxib with the lower recommended dose of celecoxib. Similarly, the three trials in older hypertensive patients that examined the cardiovascular safety of rofecoxib and celecoxib used non-comparable doses; the results of these studies indicated that rofecoxib caused more patients to have oedema and a clinically significant increase in systolic blood pressure. This difference between rofecoxib and celecoxib was not evident in studies conducted in more general populations.

AUTHORS' CONCLUSIONS

Rofecoxib was voluntarily withdrawn from global markets in October 2004 therefore there are no implications for practice concerning its use. There remains a number of questions over both the benefits and risks associated with Cox II selective agents and further work is ongoing.