Nonsteroid drug selectivities for cyclo-oxygenase-1 rather than cyclo-oxygenase-2 are associated with human gastrointestinal toxicity: a full in vitro analysis

Synthesis, COX-1/2 inhibition activities and molecular docking study of isothiazolopyridine derivatives

One of the main challenges for nowadays medicine is drugs selectivity. In COX-1 and COX-2, the active sites are composed of the same group of amino acids with the exception of the only one residue in position 523, in COX-1 is an isoleucine, while in COX-2 is a valine. Here, we presented a series of isothiazolopyridine/benzisothiazole derivatives substituted differently into an isothiazole ring, which were synthesized and investigated for their potencies to inhibit COX-1 and COX-2 enzymes by colorimetric inhibitor screening assay. All the tested compounds inhibited the activity of COX-1, the effect on COX-2 activity was differential. The mode of binding was characterized by a molecular docking study. Comparing biological activity of the investigated compounds, it was observed that compounds sharing the most similar position to flurbiprofen and meloxicam, representing the two main enzyme subdomains, achieved higher biological activity than others. It is directly related to the fit to the enzyme's active site, which prevents too early dissociation of the compounds.

Hepatotoxicity induced by coxibs: how concerned should we be?

The selective inhibitors of COX-2, coxibs, are nonsteroidal anti-inflammatory drugs (NSAIDs) that have much better gastrointestinal safety profile as compared with non-selective NSAIDs. In this review, we analyze both the epidemiological features of coxib-induced hepatotoxicity and the clinical impact of coxib-associated liver damage, based on literature data. Areas covered: We carried out a search of the databases MEDLINE (PubMed), LILACS and SCIELO, from December 1999 to January 2016, to retrieve studies exploring the real impact of coxibs in liver toxicity as compared to non-selective COX-2 inhibitor NSAIDs. Expert opinion: Although reliable data on the incidence of celecoxib- and etoricoxib-induced hepatotoxicity are lacking, because of cohort studies have been generally underpowered to detect hepatic events, coxibs have been scarcely related to hepatotoxicity. Hence, coxib-induced liver injury seems to be an uncommon event, yet exhibits a wide spectrum of damage. Increasing COX-2 drug selectivity, as for rofecoxib, valdecoxib, parecoxib, and lumiracoxib, has been associated with higher cardiovascular risk, as well as dermatological and serious hepatic reactions. The actual risk of liver toxicity from the currently approved coxibs compared with non-selective NSAIDs will be discussed. Finally, classical and novel molecular mechanisms of coxib-induced hepatotoxicity are also described.

The COX- inhibitor indomethacin reduces Th1 effector and T regulatory cells in vitro in Mycobacterium tuberculosis infection

BACKGROUND

Tuberculosis (TB) causes a major burden on global health with long and cumbersome TB treatment regimens. Host-directed immune modulating therapies have been suggested as adjunctive treatment to TB antibiotics. Upregulated cyclooxygenase-2 (COX-2)-prostaglandin E2 (PGE2) signaling pathway may cause a dysfunctional immune response that favors survival and replication of Mycobacterium tuberculosis (Mtb).

METHODS

Blood samples were obtained from patients with latent TB (n = 9) and active TB (n = 33) before initiation of anti-TB chemotherapy. COX-2 expression in monocytes and ESAT-6 and Ag85 specific T cell cytokine responses (TNF-α, IFN-γ, IL-2), proliferation (carboxyfluorescein succinimidyl ester staining) and regulation (FOXP3+ T regulatory cells) were analysed by flow cytometry and the in vitro effects of the COX-1/2 inhibitor indomethacin were measured.

RESULTS

We demonstrate that indomethacin significantly down-regulates the fraction of Mtb specific FOXP3+ T regulatory cells (ESAT-6; p = 0.004 and Ag85; p < 0.001) with a concomitant reduction of Mtb specific cytokine responses and T cell proliferation in active TB. Although active TB tend to have higher levels, there are no significant differences in COX-2 expression between unstimulated monocytes from patients with active TB compared to latent infection. Monocytes in both TB groups respond with a significant upregulation of COX-2 after in vitro stimulation.

CONCLUSIONS

Taken together, our in vitro data indicate a modulation of the Th1 effector and T regulatory cells in Mtb infection in response to the COX-1/2 inhibitor indomethacin. The potential role as adjunctive host-directed therapy in TB disease should be further evaluated in both animal studies and in human clinical trials.

NSAIDs diclofenac, indomethacin, and meloxicam highly upregulate expression of ICAM-1 and COX-2 induced by X-irradiation in human endothelial cells

BACKGROUND

It is well known that radiation exposure to the heart and the use of non-steroidal anti-inflammatory drugs (NSAIDs) increase the risk of myocardial infarction (MI). Some NSAIDs are also known to act synergistically with ionizing radiation and have radio-sensitizing effects in radiotherapy. These evidences suggest that NSAIDs may affect the risk of MI after radiation exposure to the heart. In the present study, we investigated effects of NSAIDs on radiation-induced expression of cell adhesion molecules and COX-2, which are associated with inflammation and an increased risk of MI, in human endothelial cells.

METHODS

Effects of NSAIDs on radiation-induced expression of ICAM-1, VCAM-1, E-selectin, and COX-2 were investigated in human umbilical vein endothelial cells (HUVECs). As NSAIDs, diclofenac, etodolac, indomethacin, ketoprofen, meloxicam, and rofecoxib were used.

RESULTS

Irradiation with 10 Gy increased expression of ICAM-1 and COX-2, but it did not affect expression of VCAM-1 or E-selectin. All the NSAIDs upregulated radiation-induced expression of ICAM-1 and COX-2. The extent of upregulation varied depending on the types of NSAIDs. Indomethacin, diclofenac, and meloxicam highly upregulated radiation-induced expression of ICAM-1 and COX-2. The extent of upregulation was not related to the degree of COX-2 selectivity. An NF-κB inhibitor BAY 11-7082 suppressed radiation-induced expression of ICAM-1, but it did not suppress upregulated expression of ICAM-1 or COX-2 by combination treatment with X-irradiation and meloxicam, suggesting the existence of NF-κB-independent pathways for ICAM-1 and COX-2 induction.

CONCLUSION

Indomethacin, diclofenac, and meloxicam highly upregulated radiation-induced expression of ICAM-1 and COX-2 in HUVECs, which suggests that use of these NSAIDs may increase the effects of ionizing radiation and affect the risk of MI after radiation exposure to the heart.

Effect of Parecoxib as an Adjunct to Patient-Controlled Epidural Analgesia after Abdominal Hysterectomy: A Multicenter, Randomized, Placebo-Controlled Trial

OBJECTIVE

This multicenter, randomized, placebo-controlled study evaluated the efficacy and side effects of parecoxib during patient-controlled epidural analgesia (PCEA) after abdominal hysterectomy.

METHODS

A total of 240 patients who were scheduled for elective abdominal hysterectomy under combined spinal-epidural anesthesia received PCEA plus postoperative intravenous parecoxib 40 mg or saline every 12 h for 48 h after an initial preoperative dose of parecoxib 40 mg or saline. An epidural loading dose of a mixture of 6 mL of 0.25% ropivacaine and 2 mg morphine was administered 30 min before the end of surgery, and PCEA was initiated using 1.25 mg/mL ropivacaine and 0.05 mg/mL morphine with a 2-mL/h background infusion and 2-mL bolus with a 15-min lockout. The primary end point of this study was the quantification of the PCEA-sparing effect of parecoxib.

RESULTS

Demographic data were similar between the two groups. Patients in the parecoxib group received significantly fewer self-administrated boluses (0 (0, 3) vs. 7 (2, 15), P < 0.001) and less epidural morphine (5.01 ± 0.44 vs. 5.95 ± 1.29 mg, P < 0.001) but experienced greater pain relief compared with the control group (P < 0.001). Patient global satisfaction was higher in the parecoxib group than the control group (P < 0.001). Length of hospitalization (9.50 ± 2.1, 95% CI 9.12~9.88 vs. 10.41 ± 2.6, 95% CI 9.95~10.87, P = 0.003) and postoperative vomiting (17% vs. 29%, P < 0.05) were also reduced in the parecoxib group. There were no serious adverse effects in either group.

CONCLUSION

Our data suggest that adjunctive parecoxib during PCEA following abdominal hysterectomy is safe and efficacious in reducing pain, requirements of epidural analgesics, and side effects.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01566669).

Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis

Nonsteroidal antiinflammatory drugs, including ibuprofen, are among the most commonly used medications and produce their antiinflammatory effects by blocking cyclooxygenase (COX)-2. Their use is associated with increased risk of heart attacks caused by blocking COX-2 in the vasculature and/or kidney, with our recent work implicating the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), a cardiotoxic hormone whose effects can be prevented by l-arginine. The ibuprofen salt ibuprofen arginate (Spididol) was created to increase solubility but we suggest that it could also augment the NO pathway through codelivery of arginine. Here we investigated the idea that ibuprofen arginate can act to simultaneously inhibit COX-2 and preserve the NO pathway. Ibuprofen arginate functioned similarly to ibuprofen sodium for inhibition of mouse/human COX-2, but only ibuprofen arginate served as a substrate for NOS. Ibuprofen arginate but not ibuprofen sodium also reversed the inhibitory effects of ADMA and N^G-nitro-l-arginine methyl ester on inducible NOS (macrophages) and endothelial NOS in vitro (aorta) and in vivo (blood pressure). These observations show that ibuprofen arginate provides, in one preparation, a COX-2 inhibitor and NOS substrate that could act to negate the harmful cardiovascular consequences mediated by blocking renal COX-2 and increased ADMA. While remarkably simple, our findings are potentially game-changing in the nonsteroidal antiinflammatory drug arena.-Kirkby, N. S., Tesfai, A., Ahmetaj-Shala, B., Gashaw, H. H., Sampaio, W., Etelvino, G., Leão, N. M., Santos, R. A., Mitchell, J. A. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis.

Celastrol modulates inflammation through inhibition of the catalytic activity of mediators of arachidonic acid pathway: Secretory phospholipase A2 group IIA, 5-lipoxygenase and cyclooxygenase-2

Elevated production of arachidonic acid (AA)-derived pro-inflammatory eicosanoids due to the concerted action of secretory phospholipase A₂ group IIA (sPLA₂IIA), 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2) is a common feature of many inflammatory disorders. Hence, modulation of the bioactivity of these 3 enzymes is an important strategy to control inflammation. However, the failure of drugs specific for an individual enzyme (sPLA₂IIA-, 5-LOX- or COX-2) and the success of 5-LOX/COX-2 dual inhibitors in effectively controlling inflammation in clinical trials prompted us to evaluate a common inhibitor for sPLA₂IIA, 5-LOX and COX-2 enzymes. Celastrol, a quinone methide triterpene, was selected in this regard through molecular docking studies. We provide the first evidence for celastrol's ability to inhibit the catalytic activity of sPLA₂IIA, 5-LOX and COX-2 enzymes. Celastrol significantly inhibited the catalytic activity of sPLA₂IIA (IC₅₀=6μM) in vitro, which is independent of substrate and calcium concentration. In addition, celastrol inhibited the catalytic activities of 5-LOX (IC₅₀=5μM) and COX-2 (IC₅₀=20μM) in vitro; sPLA₂IIA-induced edema and carrageenan-induced edema in mice; and lipopolysaccharide-stimulated production of PGE₂ in human neutrophils. Thus, celastrol modulates inflammatory responses by targeting multiple enzymes of AA pathway.

The Promise of Prostaglandins: Have They Fulfilled Their Potential as Therapeutic Targets for the Delay of Preterm Birth?

OBJECTIVE

The elucidation some 30 years ago by Sir Mont Liggins that the activation of the hypothalamic-pituitary-adrenal-placental axis in fetal sheep led to elevated maternal prostaglandin (PG) concentrations and the initiation of labor provided hope that targeting PG synthesis or action would lead to effective tocolysis and lowering of the human preterm birth rate. This was the "promise of PGs."

METHODS AND RESULTS

Although early trials showed that nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit PG H synthase (PGHS), delayed preterm birth by 48 hours, other trials revealed an association between NSAIDs and adverse fetal effects, including oligohydramnios, patent ductus arteriosus, necrotizing enterocolitis, intraventricular hemorrhage, and persistent pulmonary hypertension of the newborn (PPHN). Hope was revived when studies in the mid 1990s demonstrated that much of the PGs synthesized by intrauterine tissues at preterm labor were derived from the inducible isoenzyme PGHS-2. Unfortunately, administration of specific PGHS-2 inhibitors led to the same adverse fetal effects displayed by the mixed PGHS-1 and -2 NSAIDs, causing interest in the promise of PGs to wane. This led to the development of new strategies for specific PG inhibition or antagonism. One of these is the application of a specific PGF2alpha receptor blocker, Theratechnologies (THG)113.31. THG113.31 decreases the in vitro contractile activity of mouse, sheep, and human myometrium in response to exogenous PGF2alpha, delays lipopolysaccharide (LPS)-induced preterm birth in mice, and lowers uterine electromyographic activity and delays preterm birth in sheep administered RU486. There have been no observable maternal or fetal side effects with its use.

CONCLUSION

By developing new strategies based on other therapeutic targets, the promise of PGs may once again offer hope for delaying preterm birth.

Cyclic Dipeptide Shuttles as a Novel Skin Penetration Enhancement Approach: Preliminary Evaluation with Diclofenac

This study demonstrates the effectiveness of a peptide shuttle in delivering diclofenac into and through human epidermis. Diclofenac was conjugated to a novel phenylalanyl-N-methyl-naphthalenylalanine-derived diketopiperazine (DKP) shuttle and to TAT (a classical cell penetrating peptide), and topically applied to human epidermis in vitro. DKP and TAT effectively permeated into and through human epidermis. When conjugated to diclofenac, both DKP and TAT enhanced delivery into and through human epidermis, though DKP was significantly more effective. Penetration of diclofenac through human epidermis (to receptor) was increased by conjugation to the peptide shuttle and cell penetrating peptide with enhancement of 6x by DKP-diclofenac and 3x by TAT-diclofenac. In addition, the amount of diclofenac retained within the epidermis was significantly increased by peptide conjugation. COX-2 inhibition activity of diclofenac was retained when conjugated to DKP. Our study suggests that the peptide shuttle approach may offer a new strategy for targeted delivery of small therapeutic and diagnostic molecules to the skin.

Use of non-steroidal anti-inflammatory drugs and risk of breast cancer: The Spanish Multi-Case-control (MCC) study

Background

The relationship between non-steroidal anti-inflammatory drug (NSAID) consumption and breast cancer has been repeatedly studied, although the results remain controversial. Most case-control studies reported that NSAID consumption protected against breast cancer, while most cohort studies did not find this effect. Most studies have dealt with NSAIDs as a whole group or with specific drugs, such aspirin, ibuprofen, or others, but not with NSAID subgroups according to the Anatomical Therapeutic Chemical Classification System; moreover, scarce attention has been paid to their effect on different tumor categories (i.e.: ductal/non-ductal, stage at diagnosis or presence of hormonal receptors).

Methods

In this case-control study, we report the NSAID – breast cancer relationship in 1736 breast cancer cases and 1895 healthy controls; results are reported stratifying by the women’s characteristics (i.e.: menopausal status or body mass index category) and by tumor characteristics.

Results

In our study, NSAID use was associated with a 24 % reduction in breast cancer risk (Odds ratio [OR] = 0.76; 95 % Confidence Interval [CI]: 0.64–0.89), and similar results were found for acetic acid derivatives, propionic acid derivatives and COXIBs, but not for aspirin. Similar results were found in postmenopausal and premenopausal women. NSAID consumption also protected against hormone + or HER2+ cancers, but not against triple negative breast cancers. The COX-2 selectivity showed an inverse association with breast cancer (i.e. OR < 1), except in advanced clinical stage and triple negative cancers.

Conclusion

Most NSAIDs, but not aspirin, showed an inverse association against breast cancer; this effect seems to be restricted to hormone + or HER2+ cancers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2692-4) contains supplementary material, which is available to authorized users.

pH-Responsive PLGA Nanoparticle for Controlled Payload Delivery of Diclofenac Sodium

Poly(lactic-co-glycolic acid) (PLGA) based nanoparticles have gained increasing attention in delivery applications due to their capability for controlled drug release characteristics, biocompatibility, and tunable mechanical, as well as degradation, properties. However, thorough study is always required while evaluating potential toxicity of the particles from dose dumping, inconsistent release and drug-polymer interactions. In this research, we developed PLGA nanoparticles modified by chitosan (CS), a cationic and pH responsive polysaccharide that bears repetitive amine groups in its backbone. We used a model drug, diclofenac sodium (DS), a nonsteroidal anti-inflammatory drug (NSAID), to study the drug loading and release characteristics. PLGA nanoparticles were synthesized by double-emulsion solvent evaporation technique. The nanoparticles were evaluated based on their particle size, surface charge, entrapment efficacy, and effect of pH in drug release profile. About 390–420 nm of average diameters and uniform morphology of the particles were confirmed by scanning electron microscope (SEM) imaging and dynamic light scattering (DLS) measurement. Chitosan coating over PLGA surface was confirmed by FTIR and DLS. Drug entrapment efficacy was up to 52%. Chitosan coated PLGA showed a pH responsive drug release in in vitro. The release was about 45% more at pH 5.5 than at pH 7.4. The results of our study indicated the development of chitosan coating over PLGA nanoparticle for pH dependent controlled release DS drug for therapeutic applications.

A Collagen IV Matrix Is Required for Guinea Pig Gastric Epithelial Cell Monolayers to Provide an Optimal Model of the Stomach Surface for Biopharmaceutical Screening

The surface epithelial cells of the stomach represent a major component of the gastric barrier. Acell culturemodel of the gastric epithelial cell surface would prove useful for biopharmaceutical screening of new chemical entities and dosage forms. Primary cultures of guinea pig gastricmucous epithelial cellswere grown on filter inserts (Transwells®) for 3 days. Tight-junction formation, assessed by transepithelial electrical resistance (TEER) and permeability ofmannitol and fluorescein, was enhanced when collagen IV rather than collagen I was used to coat the polycarbonate filter. TEER for cells grown on collagen IV was close to that obtained with intact guinea pig gastric epithelium in vitro. Differentiation was assessed by incorporation of [3H]glucosamine into glycoprotein and by activity of NADPH oxidase, which produces superoxide. Both of these measures were greater for cells grown on filters coatedwith collagen I than for cells grown on plastic culture plates, but nomajor difference was found between cells grown on collagens I and IV. The proportion of cells, which stained positively for mucin with periodic acid Schiff reagent, was greater than 95% for all culture conditions. Monolayers grown on membranes coated with collagen IV exhibited apically polarized secretion of mucin and superoxide, and were resistant to acidification of the apical medium to pH 3.0 for 30 min. A screen of nonsteroidal anti-inflammatory drugs revealed a novel effect of diclofenac and niflumic acid in reversibly reducing permeability by the paracellular route. In conclusion, themucous cell preparation grown on collagen IV represents a good model of the gastric surface epithelium suitable for screening procedures.

The effects of the painkiller diclofenac and hypoxia on gene transcription and antioxidant system in the gills of three-spined stickleback

Aquatic organisms face multiple stressors in natural ecosystems. More and more often painkillers are detected in surface waters since their prescription has increased worldwide within the last years. Here we examined the effects of the non-steroidal anti-inflammatory drug (NSAID) diclofenac and hypoxia on three-spined sticklebacks (Gasterosteus aculeatus). We exposed sticklebacks to an environmentally relevant concentration of diclofenac (1μg/L) for 14days, to 24h of hypoxia (2.0mg O2/L), and a combination of both. Hypoxia and diclofenac both can be associated with oxidative stress in fish, but it is unclear whether they would act synergistically. Expression analysis of genes related to antioxidant response, hypoxia response, and chemical metabolism in gills showed that diclofenac alone had little effect, while the combination of hypoxia and diclofenac affected transcript levels most, indicating synergistic effects of these stressors. Of the antioxidant enzymes, only superoxide dismutase activity remained unchanged by treatments, while glutathione peroxidase (GPx) was the most affected antioxidant response on both the transcript and activity levels. Our results suggest that diclofenac may lead to suppressed catalase (CAT) activity but increased GPx activity, probably as compensatory mechanism to remove increasing H2O2 in the gills, and that this response is not affected by hypoxia. The activities of lactate dehydrogenase, CAT, and GPx also showed temporal variability during treatments, which can be attributable to tissue-specific circadian rhythms. Our study shows how responses to NSAIDs and hypoxia can interact in fish, suggesting that getting more insight into temporal variation and about the different levels of regulation of environmental responses is necessary in future studies.

Safety of Continuous Infusion Ketorolac in Postoperative Coronary Artery Bypass Graft Surgery Patients

Background:Continuous infusion ketorolac is sometimes utilized for analgesia in postoperative coronary artery bypass graft (CABG) patients despite contraindications for use. Limited literature surrounds this topic; therefore, this study was conducted to evaluate the safety of this practice. Methods: This retrospective cohort study evaluated the primary outcome of mortality and secondary outcomes of incidence of bleeding and myocardial infarction (MI). All patients who underwent isolated CABG surgeries and received continuous infusion ketorolac during the study period were included. An equal number of randomly selected isolated CABG patients served as control patients. Electronic medical records and the Society of Thoracic Surgeons (STS) database were utilized to determine baseline characteristics and outcomes; Results: One hundred and seventy-eight patients met inclusion; 89 in each group. More patients in the control group underwent on-pump surgeries (78.6% vs. 29.2%, p = 0.01) and had higher STS risk scores (1.1% vs. 0.6%, p = 0.003). There was no difference in mortality between the ketorolac group and control group (2.2% vs. 3.3%, p = 0.605). Additionally, no patients experienced a MI and there was no difference in bleeding incidence (5.5% vs. 6.7%, p = 0.58); Conclusions: No association was found between continuous infusion ketorolac and increased risk of mortality, MI, or bleeding events in postoperative CABG patients. Considerations to differences in baseline characteristics must be made when interpreting results.

Hyaluronic acid based hydroxamate and conjugates with biologically active amines: In vitro effect on matrix metalloproteinase-2

In this study, water soluble hyaluronic acid (HA) based hydroxamate and conjugates with biologically active amines and hydrazides such as p- and o-aminophenols, anthranilic, 4- and 5-aminosalicylic acids, nicotinic, N-benzylnicotinic and isonicotinic hydrazides, p-aminobenzenesulfonamide (Streptocide), p-aminobenzoic acid diethylaminoethyl ester (Procaine), and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (4-aminoantipyrene) were examined as matrix metalloproteinase-2 inhibitors (MMPIs). In a dose of 0.27-270μM, the most efficient MMPIs were HA conjugates with o-aminophenol=4-aminoantipyrine>4-aminosalicylic acid>5-aminosalicylic acid. Conjugates with Streptocide, Procaine and HA hydroxamate showed 40-50% inhibitory effect at all used concentrations. Conjugates with anthranilic acid and isonicotinic hydrazide (Isoniazid) in a dose of 0.27μM inhibited enzyme activity by ∼70%, but with the concentration increase their inhibitory effect was decreased.

In Silico Analysis of the Potential of the Active Compounds Fucoidan and Alginate Derived from Sargassum Sp. as Inhibitors of COX-1 and COX-2

INTRODUCTION

The enzyme cyclooxygenase (COX) is an enzyme that catalyzes the formation of one of the mediators of inflammation, the prostaglandins. Inhibition of COX allegedly can improve inflammation-induced pathological conditions.

AIM

The purpose of the present study was to evaluate the potential of Sargassum sp. components, Fucoidan and alginate, as COX inhibitors.

MATERIAL AND METHODS

The study was conducted by means of a computational (in silico) method. It was performed in two main stages, the docking between COX-1 and COX-2 with Fucoidan, alginate and aspirin (for comparison) and the analysis of the amount of interactions formed and the residues directly involved in the process of interaction.

RESULTS

Our results showed that both Fucoidan and alginate had an excellent potential as inhibitors of COX-1 and COX-2. Fucoidan had a better potential as an inhibitor of COX than alginate. COX inhibition was expected to provide a more favorable effect on inflammation-related pathological conditions.

CONCLUSION

The active compounds Fucoidan and alginate derived from Sargassum sp. were suspected to possess a good potential as inhibitors of COX-1 and COX-2.

Proton Pump Inhibitors Increase Incidence of Nonsteroidal Anti-Inflammatory Drug-Induced Small Bowel Injury: A Randomized, Placebo-Controlled Trial

BACKGROUND & AIMS

Some studies have reported a high incidence of small bowel injuries in 60%-80% of subjects who take nonselective nonsteroidal anti-inflammatory drugs and PPIs simultaneously. We performed a randomized, double-blind, controlled study to determine whether proton pump inhibitors (PPIs) exacerbate nonsteroidal anti-inflammatory drug-induced small bowel injury.

METHODS

Fifty-seven healthy subjects were randomly assigned groups given the cyclooxygenase (COX) 2 inhibitor celecoxib (200 mg, twice daily) plus placebo for 2 weeks (COX-2 + placebo group, n = 30), or celecoxib plus the PPI rabeprazole (20 mg, once daily) for 2 weeks (COX-2 + PPI group, n = 27). The study was performed from October 2012 through September 2013 at a tertiary medical center in Japan. All subjects were evaluated by capsule endoscopy at the start of the study and then after 2 weeks administration of celecoxib with rabeprazole or placebo. The incidence rates and the numbers of small bowel injuries (ulcers and erosions) that were observed under capsule endoscopy were compared between groups. The primary endpoint was the incidence of mucosal injuries at the second capsule endoscopy examination.

RESULTS

A significantly higher proportion of subjects in the COX-2 + PPI group developed small bowel injury (12 of 27 subjects; 44.4%) than in the COX-2 + placebo group (5 of 30 subjects; 16.7%; P = .04). Subjects in the COX-2 + PPI group had a significant increase in risk of small bowel injury compared with the COX-2 + placebo group (relative risk, 2.67; 95% confidence interval, 1.08-6.58). The number of erosions in each member of the COX-2 + PPI group was greater than in each member of the COX-2 + placebo group (P = .02). The number of ulcers did not differ between groups. Twenty-six percent of subjects in the COX-2 + PPI group developed mucosal injury in the jejunum, compared with none of the subjects in the COX-2 + placebo group (P = .003); no such trend was found in the ileum.

CONCLUSIONS

In a randomized, controlled trial, PPIs increased the risk of short-term nonsteroidal anti-inflammatory drug-induced small bowel injury. UMIN clinical trial registry number: UMIN000008883.

Regulation of arterial reactivity by concurrent signaling through the E-prostanoid receptor 3 and angiotensin receptor 1

Prostaglandin E2 (PGE2), a cyclooxygenase metabolite that generally acts as a systemic vasodepressor, has been shown to have vasopressor effects under certain physiologic conditions. Previous studies have demonstrated that PGE2 receptor signaling modulates angiotensin II (Ang II)-induced hypertension, but the interaction of these two systems in the regulation of vascular reactivity is incompletely characterized. We hypothesized that Ang II, a principal effector of the renin-angiotensin-aldosterone system, potentiates PGE2-mediated vasoconstriction. Here we demonstrate that pre-treatment of arterial rings with 1nM Ang II potentiated PGE2-evoked constriction in a concentration dependent manner (AUC-Ang II 2.778±2.091, AUC+Ang II 22.830±8.560, ***P<0.001). Using genetic deletion models and pharmacological antagonists, we demonstrate that this potentiation effect is mediated via concurrent signaling between the angiotensin II receptor 1 (AT1) and the PGE2 E-prostanoid receptor 3 (EP3) in the mouse femoral artery. EP3 receptor-mediated vasoconstriction is shown to be dependent on extracellular calcium in combination with proline-rich tyrosine kinase 2 (Pyk2) and Rho-kinase. Thus, our findings reveal a novel mechanism through which Ang II and PGE2 regulate peripheral vascular reactivity.

Salicylate, diflunisal and their metabolites inhibit CBP/p300 and exhibit anticancer activity

Salicylate and acetylsalicylic acid are potent and widely used anti-inflammatory drugs. They are thought to exert their therapeutic effects through multiple mechanisms, including the inhibition of cyclo-oxygenases, modulation of NF-κB activity, and direct activation of AMPK. However, the full spectrum of their activities is incompletely understood. Here we show that salicylate specifically inhibits CBP and p300 lysine acetyltransferase activity in vitro by direct competition with acetyl-Coenzyme A at the catalytic site. We used a chemical structure-similarity search to identify another anti-inflammatory drug, diflunisal, that inhibits p300 more potently than salicylate. At concentrations attainable in human plasma after oral administration, both salicylate and diflunisal blocked the acetylation of lysine residues on histone and non-histone proteins in cells. Finally, we found that diflunisal suppressed the growth of p300-dependent leukemia cell lines expressing AML1-ETO fusion protein in vitro and in vivo. These results highlight a novel epigenetic regulatory mechanism of action for salicylate and derivative drugs.

DOI:http://dx.doi.org/10.7554/eLife.11156.001

People have been using a chemical called salicylate, which was once extracted from willow tree bark, as medicine for pain, fever and inflammation since ancient Greece. Aspirin is derived from salicylate but is a more potent drug. Aspirin exerts its anti-inflammatory effect by shutting down the activity of proteins that would otherwise boost inflammation. Aspirin achieves this by releasing a chemical marker, called an acetyl group, to be added to these proteins via a process known as protein acetylation. However, salicylate cannot trigger protein acetylation and so it was not clear how it reduces inflammation.

An anti-diabetes drug that is converted into salicylate in the body reduces inflammation by inhibiting a protein called NF-κB. In 2001, a group of researchers reported that NF-κB becomes active when an enzyme called p300 adds an acetyl group to it. This raised the question: does salicylate reduce inflammation by blocking, instead of triggering, protein acetylation.

Now, Shirakawa et al. – who include a researcher involved in the 2001 study – show that salicylate does indeed block the activity of the p300 enzyme. Shirakawa et al. then searched a database looking for drugs that have salicylate as part of their molecular structure. The search led to a drug called diflunisal, which was even more effective at blocking p300 in laboratory tests.

Some cancers, including a blood cancer, rely on p300 to grow; diflunisal was shown to stop this kind of cancer cell from growing, both in the laboratory and in mice. Together, the experiments suggest that salicylate and drugs that share some of its structure might represent useful treatments for certain cancers, as well as other diseases that involve the p300 enzyme.

DOI:http://dx.doi.org/10.7554/eLife.11156.002

Evolution to low-dose NSAID therapy

All NSAIDs are to varying degrees associated with gastrointestinal, cardiovascular and renal adverse effects (AEs). Differences in selectivity for inhibition of the COX isozymes (COX-1/COX-2) have been used as an indicator of the likelihood of experiencing an AE, but the measure of 'selectivity' commonly used is less than desirable, and selectivity has not yielded unequivocal superior safety. Recent guidelines recommend that NSAIDs be used at the lowest effective dose and for the shortest period of time. In response, 'low-dose' NSAID formulations have been developed. Such formulations may help by reducing overall systemic exposure, thereby reducing the frequency or severity of AEs. It seems timely to review the need, rationale and application of such an approach.

Subcutaneous meloxicam suspension pharmacokinetics in mice and dose considerations for postoperative analgesia

Meloxicam is a cyclooxygenase (COX) inhibitor with a higher selectivity for cyclooxygenase‐2 (COX‐2) than for cyclooxygenase‐1 (COX‐1). In the laboratory setting, this nonsteroidal anti‐inflammatory drug (NSAID) is commonly selected for analgesia in mice and administered every 24 h. This study characterizes the plasma concentration achieved from a dose of 1.6 mg/kg of meloxicam administered once every 24 h subcutaneously for 72 h in male and female C57BL/6 mice. These values were compared, over time, to reference COX‐2 inhibition constants for meloxicam. No significant differences in trough plasma concentrations were noted between genders. The plasma concentrations were below the COX‐2 IC₅₀ after 12 h. To maintain a plasma concentration at or above the COX‐2 whole blood IC_50, the study results suggest an administration frequency of every 12 h when using a dose of 1.6 mg/kg in C57BL/6 mice.

Use of Selective Cyclooxygenase-2 Inhibitors, Other Analgesics, and Risk of Glioma

Background

Selective cyclooxygenase-2 (COX-2) inhibitors are analgesic, antipyretic, and anti-inflammatory drugs. They have been found to inhibit the development of glioma in laboratory investigations. Whether these drugs reduce the risk of glioma incidence in humans is unknown.

Methods

We conducted a matched case-control analysis using the U.K.-based Clinical Practice Research Datalink (CPRD). We identified 2,469 cases matched to 24,690 controls on age, sex, calendar time, general practice, and number of years of active history in the CPRD prior to the index date. We conducted conditional logistic regression analyses to determine relative risks, estimated as odds ratios (ORs) with 95% confidence intervals (CIs) of glioma in relation to use of selective COX-2 inhibitors, adjusted for several confounding variables.

Results

Use of selective COX-2 inhibitors was unrelated to risk of glioma (adjusted OR for 1–9 versus 0 prescriptions = 1.02; 95% CI = 0.92–1.13, 10–29 versus 0 prescriptions = 1.01; 95% CI = 0.80–1.28, ≥30 versus 0 prescriptions = 1.16; 95% CI = 0.86–1.55). Trends for increasing numbers of prescriptions for other non-steroidal anti-inflammatory drugs (NSAIDs), and non-NSAID analgesics were also not associated with glioma risk.

Conclusion

Further epidemiologic studies are needed to confirm the null relation of use of selective COX-2 inhibitors to glioma risk and to explain the discrepancy between laboratory investigations and our observational study. Impact: Use of selective COX-2 inhibitors is unrelated to glioma risk.

Non-steroidal anti-inflammatory drugs and risk of cerebrovascular events in patients with osteoarthritis: a nested case-control study

Recent studies show that the risk of cardiovascular adverse events for certain traditional non-steroidal anti-inflammatory drugs (NSAIDs) is similar to that of rofecoxib. While these results are focused on ischemic cardiomyopathy, there is little evidence concerning the risk of ischemic stroke/transient ischemic attack and hemorrhagic stroke. Additionally, there is no information on nimesulide and ketoprofen, the most frequently prescribed NSAIDs in Italy, along with diclofenac. This study aims to determine whether the use of NSAIDs is associated with an increased risk of cerebrovascular events in Italy. We performed a case-control analysis nested in a cohort of patients with osteoarthritis between 2002 and 2011 who were newly treated with NSAIDs. The patients were followed until December 31, 2012. Conditional logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (95% CI) of cerebrovascular events (index date) associated with current (until 30 days before the index date), recent (31-365 days) and past (>365 days) use of NSAIDs. Within a cohort of 29,722 patients, 1566 cases (1546 matched with controls) were identified (incidence rate = 11.0/1000 person-years). The overall rate of cerebrovascular event was not elevated with current NSAIDs overall when compared with past use. Among individual NSAIDs, diclofenac and ketoprofen were the molecules significantly associated with an increased rate of cerebrovascular events (OR = 1.53; 95% CI 1.04-2.24; OR = 1.62; 95% CI 1.02-2.58, respectively). The most frequent event was hemorrhagic stroke following the use of ketoprofen (OR = 2.09; 95% CI 1.05-4.15). Diclofenac and ketoprofen seemed to increase the risk of cerebrovascular events. These findings might influence the choice of NSAIDs according to patient characteristics.

The roles of injury and nonsteroidal anti-inflammatory drugs in the development and outcomes of severe group A streptococcal soft tissue infections

PURPOSE OF REVIEW

This review summarizes clinical and basic science evidence linking trauma and nonsteroidal anti-inflammatory drug (NSAID) use to initiation and progression of severe group A streptococcal (GAS) soft tissue infection.

RECENT FINDINGS

New evidence includes recent clinical series and controlled studies that lend support to an NSAID/GAS association, basic science studies that demonstrate unique roles for nonpenetrating injury and NSAID administration in initiation of cryptogenic GAS infection and experimental studies showing that nonselective NSAIDs accelerate disease progression and limit antibiotic efficacy in established GAS soft tissue infections. Potential mechanisms for these processes are discussed.

SUMMARY

NSAIDs are important anti-inflammatory and analgesic drugs; however, new experimental data suggest that nonselective NSAIDs do more than simply mask the signs and symptoms of developing GAS infection. A more thorough understanding of the triadic interplay of injury-triggered immune signaling, GAS soft tissue infection and NSAIDs is of significant clinical importance and could shift the current paradigm of pain management to avert the consequences of such devastating infections.

Discovery of a potent cyclooxygenase-2 inhibitor, S4, through docking-based pharmacophore screening, in vivo and in vitro estimations

Cyclooxygenase (COX; EC: 1.14.99.1), the key enzyme in prostaglandin production in the human body, is a major pharmacological target for developing anti-inflammatory agents.

Perioperative blood loss and gastrointestinal tolerability of etoricoxib and diclofenac in total hip arthroplasty (ETO-DIC study): a single-center, prospective double-blinded randomized controlled trial

OBJECTIVE

Non-selective NSAIDs can cause serious gastrointestinal side-effects. Selective COX-2 blockers are a reasonable alternative for pain treatment. They do not seem to affect platelet function and consequently cause a lower perioperative blood loss than non-selective NSAIDs. This study compared etoricoxib and diclofenac during a perioperative (9 days) period after THA to investigate total blood loss and gastrointestinal tolerability. The hypothesis was that etoricoxib is superior to diclofenac.

METHODS

A total of 100 patients (50 in each group) were included in this trial. Etoricoxib (90 mg) was administered once and diclofenac sodium (75 mg) twice daily for 9 days. Total blood loss during and after primary cementless THA was detected. The rate of adverse events (AEs) and serious adverse events (SAEs) was analyzed to detect gastrointestinal tolerability.

RESULTS

The mean total blood loss (calculated) was 1548 ± SD 468 ml in the etoricoxib (ETO) group and 1649 (SD 547) ml in the diclofenac (DIC) group. The mean duration of THA was 81 min (SD 29) in the DIC and 75 min (SD 30) in the ETO group. Hence, the mean calculated total blood loss was 101 ml higher in the DIC group. This difference was not statistically significant (p = 0.334). Fifty-six patients (28 in each group) received a cell saver retransfusion, but only one patient (ETO group) needed an additional red blood cell transfusion. The hidden blood loss was 1067 ml (SD 603) in the DIC group and 999 ml (SD 378) in the ETO group. The gastrointestinal tolerability (number of adverse and serious adverse events) was not significantly different between groups.

CONCLUSION

There was no statistically significant difference in perioperative blood loss after primary THA under etoricoxib (90 mg) compared to diclofenac (75 mg). Furthermore, no gastrointestinal superiority of etoricoxib could be detected during a short period of 9 days.

Dual effects of acetylsalicylic acid on ERK signaling and Mitf transcription lead to inhibition of melanogenesis

Acetylsalicylic acid (ASA) is widely used as an analgesic/antipyretic drug. It exhibits a wide range of biological effects, including preventative effects against heart attack and stroke, and the induction of apoptosis in various cancer cells. We previously found that ASA inhibits melanogenesis in B16 melanoma cells. However, the mechanisms of how ASA down-regulates melanin synthesis remain unclear. Here, we investigated the effect of ASA on melanogenic pathways, such as extracellular signal-regulated kinase (ERK) and microphthalmia-associated transcription factor (Mitf) transcription. ASA significantly inhibited melanin synthesis in a dose-dependent manner without oxidative stress and cell death. Semi-quantitative reverse transcription-polymerase chain reaction analysis showed that the inhibitory effect of ASA might be due to the inhibition of Mitf gene transcription. Interestingly, ASA also induced ERK phosphorylation. Additionally, treatment with PD98059, a specific ERK phosphorylation inhibitor, abolished the anti-melanogenic effect of ASA. These results suggest that the depigmenting effect of ASA results from down-regulation of Mitf, which is induced by both the induction of ERK phosphorylation and the inhibition of Mitf transcription.

Origin of the Enigmatic Stepwise Tight-Binding Inhibition of Cyclooxygenase-1

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for the treatment of pain, fever, inflammation, and some types of cancers. Their mechanism of action is the inhibition of isoforms 1 and 2 of the enzyme cyclooxygenase (COX-1 and COX-2, respectively). However, both nonselective and selective NSAIDs may have side effects that include gastric intestinal bleeding, peptic ulcer formation, kidney problems, and occurrences of myocardial infarction. The search for selective high-affinity COX inhibitors resulted in a number of compounds characterized by a slow, tight-binding inhibition that occurs in a two-step manner. It has been suggested that the final, only very slowly reversible, tight-binding event is the result of conformational changes in the enzyme. However, the nature of these conformational changes has remained elusive. Here we explore the structural determinants of the tight-binding phenomenon in COX-1 with molecular dynamics and free energy simulations. The calculations reveal how different classes of inhibitors affect the equilibrium between two conformational substates of the enzyme in distinctly different ways. The class of tight-binding inhibitors is found to exclusively stabilize an otherwise unfavorable enzyme conformation and bind significantly stronger to this state than to that normally observed in crystal structures. By also computing free energies of binding to the two enzyme conformations for 16 different NSAIDs, we identify an induced-fit mechanism and the key structural features associated with high-affinity tight binding. These results may facilitate the rational development of new COX inhibitors with improved selectivity profiles.

Addition of Berberine to 5-Aminosalicylic Acid for Treatment of Dextran Sulfate Sodium-Induced Chronic Colitis in C57BL/6 Mice

Ulcerative colitis (UC) is a common chronic remitting disease but without satisfactory treatment. Alternative medicine berberine has received massive attention for its potential in UC treatment. Conventional therapies with the addition of berberine are becoming attractive as novel therapies in UC. In the present study, we investigated the preclinical activity of a conventional oral 5-aminosalicylic acid (5-ASA) therapy plus berberine in experimental colitis. A subclinical dose of 5-ASA (200 mg/kg/day) alone or 5-ASA plus berberine (20 mg/kg/day) was orally administered for 30 days to C57BL/6 mice with colitis induced by three cycles of 2% dextran sulfate sodium (DSS). The disease severity, inflammatory responses, drug accumulation and potential toxicity of colitis mice were examined. The results showed that comparing to 5-ASA alone, 5-ASA plus berberine more potently ameliorated DSS-induced disease severity, colon shortening, and colon histological injury. Further, the up-regulation in mRNA level of colonic TNF-α as well as NFκB and JAK2 phosphorylation caused by DSS were more pronouncedly reversed in animals treated with the combination therapy than those treated with 5-ASA alone. Moreover, the addition of berberine to 5-ASA more significantly inhibited lymphocyte TNF-α secretion of DSS mice than 5-ASA alone. In the meanwhile, no extra drug accumulation or potential toxicity to major organs of colitis mice was observed with this combination treatment. In summary, our studies provide preclinical rationale for the addition of berberine to 5-ASA as a promising therapeutic strategy in clinic by reducing dose of standard therapy.

Effect of Cyclooxygenase(COX)-1 and COX-2 inhibition on furosemide-induced renal responses and isoform immunolocalization in the healthy cat kidney

Background

The role of cyclooxygenase(COX)-1 and COX-2 in the saluretic and renin-angiotensin responses to loop diuretics in the cat is unknown. We propose in vivo characterisation of isoform roles in a furosemide model by administering non-steroidal anti-inflammatory drugs (NSAIDs) with differing selectivity profiles: robenacoxib (COX-2 selective) and ketoprofen (COX-1 selective).

Results

In this four period crossover study, we compared the effect of four treatments: placebo, robenacoxib once or twice daily and ketoprofen once daily concomitantly with furosemide in seven healthy cats. For each period, urine and blood samples were collected at baseline and within 48 h of treatment starting. Plasma renin activity (PRA), plasma and urinary aldosterone concentrations, glomerular filtration rate (GFR) and 24 h urinary volumes, electrolytes and eicosanoids (PGE₂, 6-keto-PGF1_α, TxB₂), renal injury biomarker excretions [N-acetyl-beta-D-glucosaminidase (NAG) and Gamma-Glutamyltransferase] were measured. Urine volume (24 h) and urinary sodium, chloride and calcium excretions increased from baseline with all treatments. Plasma creatinine increased with all treatments except placebo, whereas GFR was significantly decreased from baseline only with ketoprofen. PRA increased significantly with placebo and once daily robenacoxib and the increase was significantly higher with placebo compared to ketoprofen (10.5 ± 4.4 vs 4.9 ± 5.0 ng ml⁻¹ h⁻¹). Urinary aldosterone excretion increased with all treatments but this increase was inhibited by 75 % with ketoprofen and 65 % with once daily robenacoxib compared to placebo. Urinary PGE₂ excretion decreased with all treatments and excretion was significantly lower with ketoprofen compared to placebo. Urinary TxB₂ excretion was significantly increased from baseline only with placebo. NAG increased from baseline with all treatments. Immunohistochemistry on post-mortem renal specimens, obtained from a different group of cats that died naturally of non-renal causes, suggested constitutive COX-1 and COX-2 co-localization in many renal structures including the macula densa (MD).

Conclusions

These data suggest that both COX-1 and COX-2 could generate the signal from the MD to the renin secreting cells in cats exposed to furosemide. Co-localization of COX isoenzymes in MD cells supports the functional data reported here.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0598-z) contains supplementary material, which is available to authorized users.

A novel algorithm for analyzing drug-drug interactions from MEDLINE literature

Drug–drug interaction (DDI) is becoming a serious clinical safety issue as the use of multiple medications becomes more common. Searching the MEDLINE database for journal articles related to DDI produces over 330,000 results. It is impossible to read and summarize these references manually. As the volume of biomedical reference in the MEDLINE database continues to expand at a rapid pace, automatic identification of DDIs from literature is becoming increasingly important. In this article, we present a random-sampling-based statistical algorithm to identify possible DDIs and the underlying mechanism from the substances field of MEDLINE records. The substances terms are essentially carriers of compound (including protein) information in a MEDLINE record. Four case studies on warfarin, ibuprofen, furosemide and sertraline implied that our method was able to rank possible DDIs with high accuracy (90.0% for warfarin, 83.3% for ibuprofen, 70.0% for furosemide and 100% for sertraline in the top 10% of a list of compounds ranked by p-value). A social network analysis of substance terms was also performed to construct networks between proteins and drug pairs to elucidate how the two drugs could interact.

Novel Activities of Select NSAID R-Enantiomers against Rac1 and Cdc42 GTPases

Rho family GTPases (including Rac, Rho and Cdc42) collectively control cell proliferation, adhesion and migration and are of interest as functional therapeutic targets in numerous epithelial cancers. Based on high throughput screening of the Prestwick Chemical Library^® and cheminformatics we identified the R-enantiomers of two approved drugs (naproxen and ketorolac) as inhibitors of Rac1 and Cdc42. The corresponding S-enantiomers are considered the active component in racemic drug formulations, acting as non-steroidal anti-inflammatory drugs (NSAIDs) with selective activity against cyclooxygenases. Here, we show that the S-enantiomers of naproxen and ketorolac are inactive against the GTPases. Additionally, more than twenty other NSAIDs lacked inhibitory action against the GTPases, establishing the selectivity of the two identified NSAIDs. R-naproxen was first identified as a lead compound and tested in parallel with its S-enantiomer and the non-chiral 6-methoxy-naphthalene acetic acid (active metabolite of nabumetone, another NSAID) as a structural series. Cheminformatics-based substructure analyses—using the rotationally constrained carboxylate in R-naproxen—led to identification of racemic [R/S] ketorolac as a suitable FDA-approved candidate. Cell based measurement of GTPase activity (in animal and human cell lines) demonstrated that the R-enantiomers specifically inhibit epidermal growth factor stimulated Rac1 and Cdc42 activation. The GTPase inhibitory effects of the R-enantiomers in cells largely mimic those of established Rac1 (NSC23766) and Cdc42 (CID2950007/ML141) specific inhibitors. Docking predicts that rotational constraints position the carboxylate moieties of the R-enantiomers to preferentially coordinate the magnesium ion, thereby destabilizing nucleotide binding to Rac1 and Cdc42. The S-enantiomers can be docked but are less favorably positioned in proximity to the magnesium. R-naproxen and R-ketorolac have potential for rapid translation and efficacy in the treatment of several epithelial cancer types on account of established human toxicity profiles and novel activities against Rho-family GTPases.

Effect of Postoperative Diclofenac on Anastomotic Strength and Histologic Healing in Rabbit Small Intestine

In this experimental study, we investigated the effects of a 5-day postoperative treatment with the nonsteroidal anti-inflammatory drug (NSAID) diclofenac on anastomotic healing in rabbits. NSAIDs are widely used analgesics in today's “fast-track surgery,” raising concerns about their potential negative effects on healing in humans. A total of 33 New Zealand White female rabbits underwent laparotomy and 2 separate end-to-end anastomoses of the ileum.. The animals were randomized to receive subcutaneous diclofenac 4 mg/kg/d (17 experimental rabbits) or subcutaneous isotonic saline 0.1 mL/kg/d (16 control rabbits) postoperatively. On the fifth postoperative day, the animals were humanely killed, and anastomotic leakage, anastomotic breaking strength, and histopathologic changes were evaluated. Breaking strength in the diclofenac group was 21% lower than in the placebo group (P = 0.027). Anastomotic leakage was found in 4 rabbits in the diclofenac group (26.7%). The rabbits treated with diclofenac demonstrated a 16% lower collagen deposition compared with the placebo group (P = 0.008). In our study, postoperative treatment with diclofenac had a negative effect on the anastomotic healing and strength in the ileum of rabbits. Caution should be taken in the use of diclofenac after gastrointestinal surgery.

An integrated safety analysis of intravenous ibuprofen (Caldolor(®)) in adults

Intravenous (IV) nonsteroidal anti-inflammatory drugs such as IV ibuprofen are increasingly used as a component of multimodal pain management in the inpatient and outpatient settings. The safety of IV ibuprofen as assessed in ten sponsored clinical studies is presented in this analysis. Overall, 1,752 adult patients have been included in safety and efficacy trials over 11 years; 1,220 of these patients have received IV ibuprofen and 532 received either placebo or comparator medication. The incidence of adverse events (AEs), serious AEs, and changes in vital signs and clinically significant laboratory parameters have been summarized and compared to patients receiving placebo or active comparator drug. Overall, IV ibuprofen has been well tolerated by hospitalized and outpatient patients when administered both prior to surgery and postoperatively as well as for nonsurgical pain or fever. The overall incidence of AEs is lower in patients receiving IV ibuprofen as compared to those receiving placebo in this integrated analysis. Specific analysis of hematological and renal effects showed no increased risk for patients receiving IV ibuprofen. A subset analysis of elderly patients suggests that no dose adjustment is needed in this higher risk population. This integrated safety analysis demonstrates that IV ibuprofen can be safely administered prior to surgery and continued in the postoperative period as a component of multimodal pain management.

Ibuprofen and Diclofenac Restrict Migration and Proliferation of Human Glioma Cells by Distinct Molecular Mechanisms

Background

Non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with anti-tumorigenic effects in different tumor entities. For glioma, research has generally focused on diclofenac; however data on other NSAIDs, such as ibuprofen, is limited. Therefore, we performed a comprehensive investigation of the cellular, molecular, and metabolic effects of ibuprofen and diclofenac on human glioblastoma cells.

Methods

Glioma cell lines were treated with ibuprofen or diclofenac to investigate functional effects on proliferation and cell motility. Cell cycle, extracellular lactate levels, lactate dehydrogenase-A (LDH-A) expression and activity, as well as inhibition of the Signal Transducer and Activator of Transcription 3 (STAT-3) signaling pathway, were determined. Specific effects of diclofenac and ibuprofen on STAT-3 were investigated by comparing their effects with those of the specific STAT-3 inhibitor STATTIC.

Results

Ibuprofen treatment led to a stronger inhibition of cell growth and migration than treatment with diclofenac. Proliferation was affected by cell cycle arrest at different checkpoints by both agents. In addition, diclofenac, but not ibuprofen, decreased lactate levels in all concentrations used. Both decreased STAT-3 phosphorylation; however, diclofenac led to decreased c-myc expression and subsequent reduction in LDH-A activity, whereas treatment with ibuprofen in higher doses induced c-myc expression and less LDH-A alteration.

Conclusions

This study indicates that both ibuprofen and diclofenac strongly inhibit glioma cells, but the subsequent metabolic responses of both agents are distinct. We postulate that ibuprofen may inhibit tumor cells also by COX- and lactate-independent mechanisms after long-term treatment in physiological dosages, whereas diclofenac mainly acts by inhibition of STAT-3 signaling and downstream modulation of glycolysis.

Effect of Rumex Abyssinicus on preneoplastic lesions in dimethylhydrazine induced colon carcinogenesis in rats

BACKGROUND

Cancer as a multistage process can be reversed or blocked by using chemopreventive agents. Colon cancer chemoprevention has been widely investigated using cyclooxygenase inhibitors and many other chemicals of synthetic or natural origin. This particular study was carried out to assess the colon cancer chemopreventive effect of hydro-methanol extract of Rumex abyssinicus rhizome on rats.

METHOD

Colon cancer chemopreventive potential of hydro-methanol extract of Rumex abyssinicus rhizome was determined based on the number and multiplicity of aberrant crypt foci (ACF). Fifteen DMH (1, 2-dimethylhydrazine) treated and five untreated Wistar female rats were used. DMH was administered subcutaneously 30 mg/kg, after its pH was adjusted to 6.5-7. Treatment groups started receiving extract after six weeks of weekly DMH injections. The rats were divided in to four groups: Group 1 received only oral normal saline, Group 2 received DMH and normal saline, Group 3 and 4 received DMH plus 250 mg/kg and 500 mg/kg extract, respectively. Specific phytoconstituents of the plant, which were reviewed from original articles, were virtually evaluated for cyclooxygenase-2 (COX-2) inhibition. The binding energies and interactions of the phytochemicals from Rumex abyssinicus against COX-2 were determined by Autodock4.2.

RESULTS

There was a statistically significant reduction (p-value < 0.05) in the number of aberrant crypt (AC) and aberrant crypt foci (ACF) at both administered doses. However, significant association (p-value > 0.05) was not observed in reducing crypt multiplicity. The docking process resulted in estimated binding energies [-6.83 kcal/mol to -7.9 kcal/mol] which are closer to the positive controls or Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) [-4.55 kcal/mol to -10.84 kcal/mol]. The phytochemical-COX-2 interaction indicated the involvement of key amino acid residues in inhibition of cyclooxygenase like ARG120, TYR355, TYR385, SER530 and GLY526.

CONCLUSIONS

Rumex abyssinicus had demonstrated a chemopreventive potential at post-initiation stage. As the virtual screening data suggested, COX-2 inhibition by the anthraquinones in the extract could be one mechanism for the observed chemopreventive effect.

Marine Diterpenoids as Potential Anti-Inflammatory Agents

The inflammatory response is a highly regulated process, and its dysregulation can lead to the establishment of chronic inflammation and, in some cases, to death. Inflammation is the cause of several diseases, including rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, and asthma. The search for agents inhibiting inflammation is a great challenge as the inflammatory response plays an important role in the defense of the host to infections. Marine invertebrates are exceptional sources of new natural products, and among those diterpenoids secondary metabolites exhibit notable anti-inflammatory properties. Novel anti-inflammatory diterpenoids, exclusively produced by marine organisms, have been identified and synthetic molecules based on those structures have been obtained. The anti-inflammatory activity of marine diterpenoids has been attributed to the inhibition of Nuclear Factor-κB activation and to the modulation of arachidonic acid metabolism. However, more research is necessary to describe the mechanisms of action of these secondary metabolites. This review is a compilation of marine diterpenoids, mainly isolated from corals, which have been described as potential anti-inflammatory molecules.

The Effect of Early Postoperative Non-Steroidal Anti-Inflammatory Drugs on Pancreatic Fistula Following Pancreaticoduodenectomy

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are used commonly for postoperative analgesia but can potentially impair healing. Their effect on pancreaticoduodenectomy (PD) outcomes is unknown. We sought to examine the impact of early postoperative NSAIDs on pancreatic fistula (PF) after PD.

METHODS

We reviewed our prospective pancreatectomy database supplemented by medication administration records, including all PDs from 2002 to 2012. Primary outcome was occurrence of clinically significant (grade B-C) PF. Secondary outcomes included major morbidity (Clavien grade III-V) and 90-day mortality. Patients were compared based on early postoperative NSAID use (first 3 days following surgery) using univariate and multivariate analyses. Subgroup analyses were conducted based on NSAID type (COX-2 inhibitors and non-selective inhibitors).

RESULTS

We included 251 PDs, of whom 127 (50.6%) patients received NSAIDs postoperatively (35.5% COX-2 inhibitors, 18.3% non-selective inhibitors, and 4.4% both). Use of any NSAIDs was associated with a non-significant increase in PF (16.5 vs 11.3%%; p = 0.23), and no difference in major morbidity and mortality. Use of non-selective inhibitors was not associated with an increase in PF (8.7 vs 15.1%; p = 0.256). COX-2 inhibitors were associated with increased PF (20.2 vs 10.5 %; p = 0.033), but no difference in major morbidity or mortality. After adjusting for Charlson comorbidity and estimated blood loss, use of COX-2 inhibitors was independently associated with PF (odds ratio 2.12; p = 0.044).

CONCLUSIONS

COX-2 inhibitors are associated with PF in the early postoperative period. While non-selective inhibitors appear safe in this setting, caution is warranted with the use of COX-2 inhibitors.

Flurbiprofen axetil increases arterial oxygen partial pressure by decreasing intrapulmonary shunt in patients undergoing one-lung ventilation

PURPOSES

In the present study, we investigated whether flurbiprofen axetil (FA) alleviates hypoxemia during one-lung ventilation (OLV) by reducing the pulmonary shunt/total perfusion (Q s/Q t) ratio, and examined the relationship between the Q s/Q t ratio and the thromboxane B2 (TXB2)/6-keto-prostaglandin F1α (6-K-PGF1α) ratio.

METHODS

Sixty patients undergoing esophageal resection for carcinoma were randomly assigned to groups F and C (n = 30 for each group). FA and placebo were administered i.v. 15 min before skin incision in groups F and C, respectively. The partial pressure of arterial oxygen (PaO2) was measured and the Q s/Q t ratio was calculated. Serum TXB2, 6-K-PGF1α, and endothelin (ET) were measured by radioimmunoassay. The relationship between TXB2/6-K-PGF1α and Q s/Q t was investigated.

RESULTS

Compared with group C, PaO2 was higher and the Q s/Q t ratio was lower during OLV in group F (P < 0.05). After treatment with FA, both serum TXB2 and 6-K-PGF1α decreased significantly (P < 0.05) but the TXB2/6-K-PGF1α ratio increased significantly (P < 0.01). Increases in the TXB2/6-K-PGF1α ratio were correlated with reductions in the Q s/Q t ratio during OLV in group F (r = -0.766, P < 0.01). There was no significant difference in serum ET between groups F and C.

CONCLUSIONS

Treatment with FA reduced the Q s/Q t ratio and further increased the PaO2 level during OLV, possibly due to upregulation of the vasoactive agent TXB2/6-K-PGF1α ratio.

Does the Preemptive Use of Oral Nonsteroidal Anti-inflammatory Drugs Reduce Postoperative Pain in Surgical Removal of Third Molars? A Meta-analysis of Randomized Clinical Trials

The purpose of this study was to investigate the effectiveness of preemptive analgesia with nonsteroidal anti-inflammatory drugs (NSAIDs) in third-molar surgery. A PubMed literature search was conducted for articles restricted to the English language using the following terms (DeCS/MeSH) or combinations: analgesia, third molar, and preemptive. From a total of 704 articles, 6 (n=420 subjects) were selected. All studies presented a low risk of bias (Cochrane criteria) but exhibited high heterogeneity of methods. Two studies were excluded from the meta-analysis because they did not have adequate numeric values (dichotomous data) for the calculations. Preemptive analgesia showed no significant benefit (n=298, P=.2227, odds ratio: 2.30, 0.60-8.73) in reducing postoperative pain after removal of lower impacted third molars. However, there was a probable direct relationship between the effectiveness of NSAIDs in preemptive analgesia for removal of third molars and its selectivity for the cyclooxygenase-2 (COX-2). Preemptive analgesia did not have a significant effect in reducing postoperative pain after removal of lower impacted third molars. More homogeneous and well-delineated clinical studies are necessary to determine a possible association between NSAIDs' selectivity for COX-2 and treatment effectiveness.

5-Aminosalicylic acid, a specific drug for ulcerative colitis

OBJECTIVE

The etiology of the inflammatory bowel diseases is unknown, although genetic factors play a role, and tobacco smoking has opposite effect on the two entities. Inflammation is central in the pathogenesis, and treatment is aiming to suppress it. The active part of salazopyrin, the oldest drug in use in the treatment of ulcerative colitis, is 5-aminosalicylic acid (5-ASA). In the present paper, we wanted to discuss the etiology and pathogenesis of ulcerative colitis in relation to the beneficial effects of 5-ASA and particularly whether this compound has a specific effect on ulcerative colitis.

METHODS/RESULTS

5-ASA seems to have a selective positive effect on ulcerative colitis in inducing remission, preventing relapse and possibly reducing the risk of cancer. In contrast to other agents used in the treatment of ulcerative colitis, 5-ASA does not have any known anti-inflammatory effect on other organs or other colonic inflammatory diseases like diverticulitis. Moreover, the effect on experimental colitis in rodents is not convincing.

CONCLUSION

5-ASA seems to have a specific effect on the inflammation in ulcerative colitis. Research on the mechanism of its action may give information on the etiology of ulcerative colitis. 5-ASA is a first-line treatment that should be given once daily in high doses and for long term to reduce the possibility of recurrence and risk of colonic cancer. Side effects with 5-ASA are rare, and every patient with ulcerative colitis who tolerate this drug, should be treated with 5-ASA.

Effects of nimesulide, a selective COX-2 inhibitor, on cardiovascular function in 2 rat models of diabetes

Cyclooxygenase-2 (COX-2) has been found to be activated in diabetes. We investigated whether nimesulide (selective COX-2 inhibitor) alters cardiovascular responses to adrenaline in 2 rat models of diabetes. Wistar rats (5-week old) were continuously fed a normal or high-fructose diet (60% of caloric intake). At week 2, half of the rats in each diet regimen were given streptozotocin (STZ) (60 mg/kg, intravenously). At week 6, cardiovascular effects of adrenaline (6 and 16 × 10 mol·kg·min, intravenously) were measured in 4 groups of thiobutabarbital-anesthetized rats (control, fructose, STZ, and fructose-streptozotocin [F-STZ]) before and after the injection of nimesulide (3 mg/kg, intravenously). Both the STZ and F-STZ groups exhibited hyperglycemia and significantly (P < 0.05) reduced left ventricular contractility, mean arterial pressure, arterial and venous resistance, and mean circulatory filling pressure (index of venous tone) responses to adrenaline, relative to the control and fructose groups. Nimesulide did not affect responses in the control and fructose groups but increased the venous and, to a less extent, arterial constriction to adrenaline in both the groups of diabetic rats. The cardiac contractile responses, however, were not altered after nimesulide treatment. The results show that nimesulide partially restored arterial and venous constriction to adrenaline in rats with STZ- and F-STZ-induced diabetes.