Owing to their phenomenal electrical and mechanical properties, carbon nanotubes (CNT) have been an area of intense research since their discovery in 1991. Different applications for these nanoparticles have been proposed, among others, in electronics and optics but also in the medical field. In parallel, emerging studies have suggested potential toxic effects of CNT while others did not, generating some conflicting outcomes. These discrepancies could be, in part, due to different suspension approaches used and to the agglomeration state of CNT in solution. In this study, we described a standardized protocol to obtain stable CNT suspensions, using two biocompatible dispersants (Pluronic F108 and hydroxypropylcellulose) and to estimate the concentration of CNT in solution. CNT appear to be greatly individualized in these two dispersants with no detection of remaining bundles or agglomerates after sonication and centrifugation. Moreover, CNT remained perfectly dispersed when added to culture medium used for in vitro cell experiments. We also showed that Pluronic F108 is a better dispersant than hydroxypropylcellulose. In conclusion, we have developed a standardized protocol using biocompatible surfactants to obtain reproducible and stable multi-walled carbon nanotubes suspensions which can be used for in vitro or in vivo toxicological studies.

Thromboxane A2 (TXA2) and 8-iso-PGF2α are two prostanoid agonists of the thromboxane A2 receptor (TP), whose activation has been involved in platelet aggregation and atherosclerosis. Agents able to counteract the actions of these agonists are of great interest in the treatment and prevention of cardiovascular events. Here, we investigated in vitro and in vivo the pharmacological profile of BM-520, a new TP antagonist. In our experiments, this compound showed a great binding affinity for human washed platelets TP receptors, and prevented human platelet activation and aggregation induced by U-46619, arachidonic acid and 8-iso-PGF2α. The TP receptor antagonist property of BM-520 was confirmed by its relaxing effect on rat aorta smooth muscle preparations precontracted with U-46619 and 8-iso-PGF2α. Further, its TP antagonism was also demonstrated in vivo in guinea pig after a single intravenous injection (10mgkg−1). We conclude that this novel TP antagonist could be a promising therapeutic tool in pathologies such as atherosclerosis where an increased production of TXA2 and 8-iso-PGF2α, as well as TP activation are well-established pathogenic events.

Atherosclerotic cardiovascular disease, according to World Health Organization, is the primary cause of heart disease and stroke. Atherosclerosis is a chronic vascular disease whose development is influenced by several mediators. Among them, the action of eicosanoïds such as thromboxane A2 and 8-iso-PGF2α have recently received a lot of attention. The aim of our study was the evaluation of benefits of original molecules, synthesised in our lab, targeting the thromboxane receptor (TP) in an apo E deficient mouse. We previously demonstrated in several in vitro and in vivo pharmacological experiments that our original sulfonylurea derivate, BM-573 was a potent combined inhibitor of the thromboxane synthase and antagonist of TP. Since TP is implied in atherosclerosis development, such antagonist could have a great therapeutic impact in atherogenesis. To test the efficacy of BM-573 in atherogenesis, the effect of 10 weeks of treatment with BM573 (10 mg/kg) on early aortic atherosclerotic lesions of apo E deficient mice was assessed. These mice were fed with chow diet, with spontaneous increase of total plasma cholesterol and triglycerides. In this experiment, while BM-573 did not affect body weight, it significantly decreased early atherogenesis lesions confirmed by macroscopic, microscopic and biochemical analysis. These results confirm that selective antagonism of TP receptor is effective in reducing atherosclerotic lesion in apo E deficient mice. Consequently, BM-573 could be a potential drug for prevention of atherosclerosis.

Introduction: Human embryonic stem cells (hES) have emerged as an attractive and promising new therapeutic approach for treatment of heart diseases. The aim of this study was to evaluate in rats with acute myocardial infarction (MI): 1) effects of myocardial transplantation of undifferentiated hES on left ventricular (LV) function and morphology and 2) to determine whether potential improvement in LV function requires the presence of hES in the myocardium. Methods:Male Sprague-Dawley rats∼200 g were used. MI was induced by cryo-injury (protocol 1) and by ligation of left coronary artery (protocol 2). These procedures resulted in anterior MI engaging ∼30-40% of left ventricle (LV). In the protocol 1, the rats were randomized into two groups: rats with MI treated with vehicle (n = 8) and rats with MI treated with 1 million hES cells (n = 8). Rats treated with hES cells received cyclosporine (5 mg/kg/d). The hES cells were suspended in 0,05 ml buffer and transplanted by intramyocardial injection into the viable myocardium close to the infracted area directly after cryo-injury. The rats were followed for 1 week. In order to evaluate hypothetical paracrine effects of hES, in the protocol 2, the rats were randomised into three groups: rats with MI treated with vehicle (n = 4), rats with MI treated with cell medium (n = 6) and rats with MI treated with supernatant extracted from hES cell culture (n = 6). The animals received i.p. injections 3 times/week during 4 weeks. All animals were investigated with transthoracal echocardiography, continuous ECG and LV catheterization. Post-mortem, the hearts were evaluated histologically. Results: In the protocol 1 neither deaths nor arrhythmias occurred in the rats treated with hES cells. dP/dT was similar in both groups. There were no signs of abnormal tissue growth at the site of hES cell engraftment after one week. There was no difference in the indices of LV systolic function while diastolic function was significantly improved in the hES rats (p < 0.05). hES were detected in 1/8 rats in the infarcted area. In the protocol 2, no difference was found between the groups in indices of LV function and morphology after 4 weeks of treatment. Conclusion: Transplantation of undifferentiated hES cells have positive effect on LV diastolic function in the rat model of acute MI. This effect requires the presence of hES in the tissue. The use of hES may be an important approach for cardio-reparation and reconstitution of normal cardiac structure and function in the future.

A series of substituted (+/-)3,5-diphenyl-2-thioxoimidazolin-4-ones was synthesized in order to design new type-2 cyclooxygenase (COX-2) inhibitors. This study has led to molecules which completely inhibit human recombinant COX-2 at 50 microM. Molecular modelling highlighted drug interactions with the active site of both cyclooxygenases and suggested modifications to enhance the selectivity of the compounds. In human blood, COX-2 expression was then induced by LPS, and the inhibitory potency of these drugs was disappointing. This weak activity was attributed to a poor aqueous stability of these imidazolidinones substituted by two aryl in position 3 and 5 (15 min < t(1/2) < 130 min). The improvement of the stability of this heterocycle could generate a novel template to treat COX-associated diseases such as arthritis, rheumatoid polyarthritis and cancer.

COPD (Chronic Obstructive Pulmonary Disease) and bronchial asthma are two severe lung diseases which represent a major problem of world public health. Leukotrienes and prostanoids play an important role in the pathogenesis of pulmonary diseases. Prostanoids: prostaglandins (PGs) and thromboxane A2 (TXA2), the cyclooxygenase metabolites of arachidonic acid are implicated in the inflammatory cascade that occurs in asthmatic airways. Recently, the roles played by isoprostanes or prostaglandin-like compounds nonenzymatically generated via peroxidation of membrane phospholipids by reactive oxygen species, in particular F2-isoprostanes, in pulmonary pathophysiology have been highlighted. This article aims to provide an overview of the role of prostanoids and isoprostanes in the pathogenesis of COPD and asthma and to discuss the pharmacological strategies developed in prevention and/or treatment of these pathologies.

Rapid restoration of coronary blood flow following a period of myocardial ischemia (due to coronary occlusion) is mandatory to preserve the cardiac muscle. Reperfusion, however, not necessarily restores cardiac function, and cellular damage of the cardiac muscle cells following reperfusion (reperfusion injury) is well documented. The aim of this study was to investigate the effects of reperfusion on left ventricular (LV) hemodynamics and on left ventriculo-arterial (VA) coupling in acutely ischemic pigs.

Thromboxane A2 (TXA2) is a key mediator of platelet aggregation and smooth muscle contraction. Its action is mediated by its G protein-coupled receptor of which two isoforms, termed TPα and TPβ, occur in humans. TXA2 has been implicated in pathologies such as cardiovascular diseases, pulmonary embolism, atherosclerosis, and asthma. This study describes the pharmacological characterization of BM-613 [N-n-pentyl-N′-[2-(4′-methylphenylamino)-5-nitrobenzenesulfonyl]urea], a new combined TXA2 receptor antagonist and TXA2 synthase inhibitor. It exhibits a strong affinity for human platelet TP receptors (IC50 = 1.4 nM), TPα and TPβ expressed in COS-7 cells (IC50 = 2.1 and 3.1 nM, respectively), and TPs expressed in human coronary artery smooth muscle cells (IC50 = 29 μM). BM-613 shows a weak ability to prevent contraction of isolated rat aorta (ED50 = 1.52 μM) and guinea pig trachea (ED50 = 2.5 μM) induced by TXA2 agonist U-46619 (9.11-dideoxy-9.11-methanoepoxy-prostaglandin F2). Besides, BM-613 antagonizes TPα (IC50 = 0.11 μM) and TPβ (IC50 = 0.17 μM) calcium mobilization induced by U-46619 and inhibits human platelet aggregation induced by U-46619 (ED50 = 0.278 μM), arachidonic acid (ED50 = 0.375 μM), and the second wave of ADP. BM-613 also dose dependently prevents TXA2 production by human platelets (IC50 = 0.15 μM). In a rat model of ferric chloride-induced thrombosis, BM-613 significantly reduces weight of formed thrombus by 79, 49, and 28% at 5, 2, and 1 mg/kg i.v., respectively. In conclusion, BM-613 is a dual and potent TP receptor antagonist and TXA2 synthase inhibitor characterized by a strong antiplatelet and antithrombotic potency. These results suggest that BM-613 could be a potential therapeutic drug for thrombotic disorders.

A series of aromatic sulfonamides incorporating indane moieties were prepared starting from commercially available 1- and 2-indanamine, and their activity as inhibitors of two carbonic anhydrase (CA, EC 4.2.1.1) isozymes, hCA I and II was studied. The new sulfonamides incorporating acetamido, 4-chloro-benzoyl, valproyl, tetra-, and pentafluorobenzoyl moieties acted as very potent inhibitors of the slow red blood cell isozyme hCA I (Kis in the range of 1.6–8.5 nM), which usually has a lower affinity for such inhibitors, as compared to isozyme II. Some derivatives also showed excellent hCA II inhibitory properties (Kis in the range of 2.3–12 nM), but the anticonvulsant activity of these sulfonamides was rather low as compared to that of other sulfonamide/sulfamate CA inhibitors, such as methazolamide. Furthermore, the 2-amino/acetamido-indane-5-sulfonic acids prepared during this work also showed interesting CA inhibitory properties, with inhibition constants in the range of 43–89 nM against the two isozymes, being among the most potent sulfonic acid CA inhibitors reported so far.

The present study was undertaken in order to characterize the antiplatelet and antithrombotic effects of BM-573 ( N-tert- butyl- N '-[2-(4'-methylphenylamino)-5-nitrobenzenesulfonyl]urea), an original combined thromboxane receptor antagonist and thromboxane synthase inhibitor in rats, and to determine its effects on mice bleeding time. Intraperitoneal injection of a single dose of 5 mg/kg of BM-573 to rats inhibited U-46619-induced washed platelet aggregation 30 minutes, 1, 2 and 4 hours after drug administration with a maximum antiplatelet effect observed after 1 and 2 hours. In a rat model of thrombosis induced by ferric chloride application on the abdominal aorta, BM-573 at doses of 5, 2, 0.5 and 0.2 mg/kg significantly reduced the thrombus weight by 92.53 %. 80.20 %, 64.75 % and 18.21 %, respectively. Time to occlusion of abdominal aorta in BM-573-treated group (41.50+/-5.21 min) was significantly prolonged compared to the vehicle-treated rats (16.16+/-0.79 min). BM-573, as furegrelate, seratrodast and acetylsalicylic acid did not affect the tail bleeding time induced by tail transection in mice compared to vehicle-treated mice. Moreover, BM-573, a close derivative of the loop diuretic torasemide failed to induce a significant increase in diuresis in rat and did not produce a decrease in blood glucose concentration as observed with the sulfonylurea glibenclamide. In conclusion, we have demonstrated that the nitrobenzenic sulfonylurea original receptor and thromboxane synthase inhibitor, potent antithrombotic agent that does not affect bleeding time. Moreover, the diuretic torasemide glycemia.

The aim of this work is to evaluate the anti-thromboxane activity of two pure enantiomers of (R,S)-BM-591, a nitrobenzene sulfonylurea chemically related to torasemide, a loop diuretic. The drug affinity for thromboxane A2 receptor (TP) of human washed platelets has been determined. In these experiments, (R)-BM-591 (IC50 = 2.4+/-0.1 nM) exhibited a significant higher affinity than (S)-BM-591 (IC50 = 4.2+/-0.15 nM) for human washed platelets TP receptors. Both enantiomers were stronger ligands than SQ-29548 (IC50 = 21.0+/-1.0 nM) and sulotroban (IC50 = 930+/-42 nM), two reference TXA2 receptor antagonists. Pharmacological characterisations of (S)-BM-591 and (R)-BM-591 were compared in several models. Thus, (R)-BM-591 strongly prevented platelet aggregation induced by arachidonic acid (AA) (600 microM) and U-46619 (1 microM) while (S)-BM-591 showed a lower activity. On isolated tissues pre-contracted by U-46619, a stable TXA2 agonist, (S)-BM-591 was more potent in relaxing guinea-pig trachea (EC50 = 0.272+/-0.054 microM) and rat aorta (EC50 = 0.190+/-0.002 microM) than (R)-BM-591 (EC50 of 9.60+/-0.63 microM and 0.390+/-0.052 microM, respectively). Moreover, at 1 microM, (R)-BM-591 totally inhibited TXA2 synthase activity, expressed as TXB2 production from human platelets, while at the same concentration, (S)-BM-591 poorly reduced the TXB2 synthesis (22%). Finally, in rats, both enantiomers lost the diuretic activity of torasemide. In conclusion, (R)-BM-591 exhibits a higher affinity and antagonism on human platelet TP receptors than (S)-BM-591 as well as a better thromboxane synthase inhibitory potency. In contrast, (S)-BM-591 is more active than the (R)-enantiomer in relaxing smooth muscle contraction of rat aorta and trachea guinea pig. Consequently, (R)-BM-591 represents the best candidate for further development in the field of thrombosis disorders.