Sodium N-(methylsulfonyl)-N-(4-nitro-2-phenoxyphenyl)sulfamate: a water-soluble nimesulide prodrug for parenteral use.

Several nimesulide preparations (i.e., tablet form, gels) have been marketed, but no parenteral solution has achieved the market because of their low wettability and unsatisfactory chemical-physical properties required for parenteral use. In this paper we describe the synthesis of the nimesulide prodrug 1 and its anti-inflammatory and antihyperalgesic properties. Pharmacological studies, carried out to evaluate the in vivo anti-inflammatory and analgesic activities of compound 1 and nimesulide, showed that sodium sulfamate 1 is an effective nimesulide prodrug that can be administered by parenteral route, undergoing a satisfactory absorption and an extensive transformation into the active nimesulide compound. Moreover, the evaluation of the plasma concentrations of nimesulide after rat treatment with compound 1 showed an increased and dose-dependent release of nimesulide. In contrast, the plasma concentrations of nimesulide, after "native" drug administration, still remain substantially unchanged. These preliminary results prompt further investigations on this prodrug as a possible candidate for parenteral use.

A cortical GABA-5HT interaction in the mechanism of action of the antidepressant trazodone.

The aim of the study was to investigate whether the antidepressant trazodone (TRZ), a serotonin-2 receptor antagonist/reuptake inhibitor, modifies gamma-amino-butyric acid (GABA) extracellular levels in the cerebral cortex, by acting on 5-HT(2A) receptors, and through this mechanism increases 5-HT levels. For this purpose the effect of TRZ on the release of GABA was studied in adult male rats in synaptosomes, cortical slices, and "in vivo" by microdialysis. In cortical slices, the release of both GABA and 5-HT was determined. GABA and 5-HT were identified and their levels quantified by HPLC. The inhibition of 5-HT uptake by TRZ was also measured. In synaptosomes, TRZ antagonized dose-dependently, at concentrations from 10(-10) to 10(-6) M, the increase in GABA release induced by (+/-)DOI, a 5-HT(2A/2C) agonist, and the alpha receptor agonist phenylephrine, both 10(-6) M. The pIC50 values were 8.31+/-0.24, and 5.99+/-0.52, respectively. In the same preparation, [3H]5-HT accumulation was inhibited by citalopram and TRZ with pIC(50) of 7.8+/-0.44 and 5.9+/-0.09, respectively, a finding confirming the weak activity of TRZ in comparison with a SSRI. In cortical slices, TRZ exerted a biphasic effect on GABA release. At concentrations from 10(-10) to 10(-7) M it inhibited and from 10(-6) to 10(-4) M increased GABA release. 5-HT release was enhanced by TRZ throughout the entire range of concentrations tested. However, the increase was delayed after low and rapid after high concentrations. AMI-193, a 5-HT(2A) antagonist (10(-10) to 10(-5) M), reduced GABA release in a dose-response manner, while it induced an increase of 5-HT outflow. On the contrary, (+/-)DOI (10(-10) to 10(-5) M) increased GABA release and inhibited 5-HT levels. Perfusion with the GABA(A) receptor antagonist bicuculline was also followed by an increase in 5-HT release. In microdialysis experiments, TRZ 1.25 mg kg(-1) s.c. brought about a decrease in GABA extracellular levels, while an increase was found after the dose of 2.5 mg kg(-1). These findings demonstrate that TRZ, at concentrations which do not inhibit 5-HT uptake, reduces the cortical GABAergic tone by decreasing GABA extracellular levels, through the blockade of 5-HT(2A) receptors. The attenuation of GABAergic tone is responsible for an increase in 5-HT levels. A further increase also results from 5-HT uptake inhibition caused by higher doses of TRZ. The ensuing high 5-HT levels enhance GABA release, which in turn inhibits 5-HT release.

Bendazac lysine inhibition of human lens epithelial cell adhesion to polymethylmethacrylate intraocular lenses.

The aim of the present work was to evaluate the effect of bendazac lysine on the human lens epithelial cell line HLE-B3 adhesion to polymethylmethacrylate (PMMA) intraocular lenses (IOLs). After adherence to IOLs, cells were incubated in the presence of the drug for 24 h. The number of cells contained in a 6-mm(2) area was then counted with an inverted phase microscope and adherent cells were distinguished from detached floating cells by focusing through the medium. Results obtained show that bendazac is able to induce a linear dose-dependent inhibition of HLE-B3 adhesiveness to PMMA IOLs. In particular, treatment with bendazac 33, 100 and 300 microM resulted in a 15, 32 and 54% inhibition, respectively. Statistical analysis shows that this effect is significant at 100 microM (p < 0.05) and 300 microM (p < 0.01). The analysis of the effects of bendazac on the viability and on the proliferative capacity of HLE-B3 cells did not show any drug-related toxicity up to the concentration of 400 microM. The present study demonstrates that bendazac lysine is able to inhibit adhesion of lens epithelial cells to PMMA IOLs and suggests the potential beneficial use of this drug in preventing secondary cataract development.

Synthesis and COX-2 inhibitory properties of N-phenyl- and N-benzyl-substituted amides of 2-(4-methylsulfonylphenyl)cyclopent-1-ene-1-carboxylic acid and of their pyrazole, thiophene and isoxazole analogs.

Some N-phenyl- (7a-10a) and N-benzyl-substituted (7b-10b) amido analogs of cyclooxygenase (COX-2) selective tricyclic non-steroidal anti-inflammatory drugs have been synthesized with the aim to obtain information on the structural requirements for the COX-inhibitory activity. Compounds 7-10 were tested in vitro for their inhibitory properties only towards COX-2 enzyme by measuring prostaglandin E2 (PGE2) production on activated J774.2 macrophages. Some of the new compounds (7a, 8a, 9a and 9b) showed a modest activity, with percentage inhibition values near 30% at a concentration of 10 microM. These data have been tentatively explained by a conformational study which indicates that at least the N-phenyl-substituted amides 7a-9a present steric hindrances which may prevent a good interaction with COX-2 active site.

Acetaminophen down-regulates interleukin-1beta-induced nuclear factor-kappaB nuclear translocation in a human astrocytic cell line.

In previous studies performed to elucidate acetaminophen mechanism of action, we demonstrated that acetaminophen inhibits prostaglandin E2 production by interleukin (IL)-1beta-stimulated T98G human astrocytic cells, without affecting cyclooxygenase-2 enzymatic activity. As this result suggests an effect at transcriptional level, we examined whether the drug interferes with the activation of nuclear factor (NF)-kappaB and STAT3 transcription factors and with SAPK signal transducing factor. Western blot analysis of IkappaBalpha protein in the cytoplasm of IL-1beta-stimulated T98G cells and electrophoretic mobility shift assay (EMSA) on corresponding nuclear extracts indicate that acetaminophen (10-1000 microM) dose-dependently inhibits both IkappaBalpha degradation and NF-kappaB nuclear translocation. In the same cell type neither IL-1beta-dependent SAPK activation nor IL-6-induced STAT3 phosphorylation is affected by the drug. These data indicate that therapeutic concentrations of acetaminophen induce an inhibition of IL-1beta-dependent NF-kappaB nuclear translocation. The selectivity of this effect suggests the existence of an acetaminophen specific activity at transcriptional level that may be one of the mechanisms through which the drug exerts its pharmacological effects.

Benzydamine inhibits monocyte migration and MAPK activation induced by chemotactic agonists.

1. The present study was aimed to investigate the effect of benzydamine, an anti-inflammatory drug devoid of activity on arachidonic acid metabolism, on monocyte chemotaxis and to define the possible biochemical correlates of activity. 2. Benzydamine inhibited monocyte chemotaxis in response to three classes of chemoattractants: the prototypic CC-chemokine CCL2 (MCP-1), the microbial product fMLP and the complement cascade component C5a. The effect was dose-dependent with IC50's of 100, 50 and 45 microm for MCP-1/CCL2, fMLP and C5a, respectively. At the dose of 100 microm, the effect resulted in a 50+/-10% inhibition of MCP-1/CCL2-induced chemotaxis and 53+/-6 and 54+/-5% inhibitions of chemotaxis in response of fMLP and C5a, respectively (n=3). 3. Receptor expression as well as calcium fluxes in response to chemoattractants were not affected by benzydamine. 4. Benzydamine strongly inhibited chemoattractant-induced activation of the mitogen-activated protein kinase (MAPK) ERK1/2, and of its upstream activator kinase MEK1/2. ERK1/12 activation in response to chemoattractants was 89-98% inhibited by a 100 microm concentration of benzydamine with an IC50 of 30 microm. 5. Under the same experimental conditions, pretreatment with 100 microm benzydamine caused a 75-89% inhibition of p38 activation (IC50 25 microm). 6. These results indicate that the anti-inflammatory activity of benzydamine is exerted at multiple levels, including monocyte migration to chemotactic factors associated to a blockage of ERK and p38 MAPK pathways.

Synthesis and prostaglandin synthase inhibitory activity of new aromatic O-alkyloxime ethers substituted with methylsulfonamido or methylsulfonyl groups on their aliphatic portion.

Some aromatic O-alkyloxime ethers substituted with methylsulfonamido (7) or methylsulfonyl (8) groups on their aliphatic portions were prepared as analogues of structurally related cyclooxygenase (COX) inhibitors (6) bearing a carboxylic group typical of the classic non-steroidal anti-inflammatory drugs (NSAIDs) in the place of the sulfurated moiety. In addition, also analogues of compounds 8 in which the aliphatic chain is further lengthened by 1 (9), 2 (10), or 3 (11) carbon atoms were synthesized. All compounds (7-11) were tested in vitro towards COX2, and compounds 7-9 towards COX1, by measuring prostaglandin E2 (PGE(2)) production in activated J774.2 macrophages and U937 cell lines, respectively. While all new compounds were found to possess little or no activity on the COX2 isoenzyme, some of these (7a-7d, 8a, 8d, 9e and 9f) appeared to possess an appreciable activity on COX1, with % inhibition values at a concentration of 1 microM ranging from 30% of 8a to 76% of 9e. The COX1 selectivity of the new compounds was tentatively explained by means of a docking study of one of the more active compounds tested on both COX isoenzymes (7d), which indicated a different number of hydrogen bonding interactions with the Arg120 of the active sites of the two enzymes, and therefore, an energetically favored interaction (3.5 kcal/mol) with COX1, compared with COX2.

Synthesis of heteroaromatic analogues of (2-aryl-1-cyclopentenyl-1-alkylidene)-(arylmethyloxy)amine COX-2 inhibitors: effects on the inhibitory activity of the replacement of the cyclopentene central core with pyrazole, thiophene or isoxazole ring.

Several heteroaromatic analogues of (2-aryl-1-cyclopentenyl-1-alkylidene)-(arylmethyloxy)amine COX-2 inhibitors, in which the cyclopentene moiety was replaced by pyrazole, thiophene or isoxazole ring, were synthesized, in order to verify the influence of the different nature of the central core on the COX inhibitory properties of these kinds of molecules. Among the compounds tested, only the 3-(p-methylsulfonylphenyl) substituted thiophene derivatives 17 and 22, showed a certain COX-2 inhibitory activity, accompanied by an appreciable COX-2 versus COX-1 selectivity. Only one of the 1-(p-methylsulfonylphenyl)pyrazole compounds (16) displayed a modest inhibitory activity towards both type of isoenzymes, while the pyrazole 1-(p-aminosulfonylphenyl) substituted 12 proved to be significantly active only towards COX-1. All the isoxazole derivatives were inactive on both COX isoforms.

Aryl-substituted methyleneaminoxymethyl (MAOM) analogues of diarylcyclopentenyl cyclooxygenase-2 inhibitors: effects of some structural modifications on their biological properties.

The (E)-[2-(4-aminosulfonylphenyl)-1-cyclopentenyl-1-methyliden]-(arylmethyloxy)amines (6a,b), which are the sulfonamidic analogues of the previously described methylsulfonyl derivatives 5a,b, and their corresponding sulfides (7a,b) and sulfoxides (8a,b) were synthesised in order to obtain information about the role played by these different sulphur-containing groups in the cyclooxygenase-2 inhibitory activity of this class of compounds. In addition, other chemical manipulations concerning the oxime-ether substituent of this type of derivatives were affected by preparing compounds 9a,b, which present a methyl group on the oximic carbon of the oxime-ether chain of 5a,b, and compounds 10 and 11, in which the atomic sequence (C=NOCH(2)) of the MAOMM of 8b and 5b, respectively, is inverted. Compounds 6-11 were tested in vitro for their inhibitory activity towards COX-1 and COX-2 by measuring prostaglandin E2 (PGE2) production in U937 cell lines and activated J774.2 macrophages, respectively. Some of the new compounds showed an appreciable in vitro COX-2 inhibitory activity, with IC(50) values in the microM (7a,b, 8a and 9b) or sub-microM (8b) range. This last compound was also assayed in vivo for its antiinflammatory activity by means of the carrageenan-induced paw edema test in rats. No inhibitory effects were detected up to dose of 30 mg kg(-1) orally administered.

(E)-[2-(4-Methylsulphonylphenyl)-1-cyclopentenyl-1-methyliden](arylmethyloxy)amines. Methyleneaminoxymethyl (MAOM) analogues of diarylcyclopentenyl cyclooxygenase-2 inhibitors: synthesis and biological properties.

The (E)-[2-(4-Methylsulphonylphenyl)-1-cyclopentenyl-1-methyliden](methyloxy)amine (5) and (arylmethyloxy)amines (6-12) were designed in order to verify the effects on the biological properties of the substitution of an aryl of selective diarylcyclopentenyl cyclooxygenase-2 (COX-2) inhibitors of type 3 with a methyleneaminoxymethyl moiety (MAOMM). Compounds 5-12 were tested in vitro for their inhibitory activity towards COX-1 and COX-2 by measuring prostaglandin E2 (PGE2) production in U937 cell lines and activated J774.2 macrophages, respectively. The compound with the highest in vitro activity towards COX-2 (9) was also assayed in vivo for its antiinflammatory activity by means of the carrageenan-induced paw edema test in rats. Some of the new compounds showed an appreciable in vitro COX-2 inhibitory activity, with IC(50) values in the microM (6,7,9,10,11) range. Compound 9 also exhibited an appreciable in vivo activity (29% inhibition at a dose of 30 mg kg(-1)) when administered intraperitoneally. The structural parameters of 9 were determined by X-ray crystallographic analysis.