Physico-chemical characterization of disoxaril-dimethyl-beta-cyclodextrin inclusion complex and in vitro permeation studies.

In this work we evaluated the ability of 2,6-di-O-methyl-beta-cyclodextrin (DM-beta-Cyd) to include the anti-rhinovirus drug Disoxaril (WIN 51711), increasing its water solubility and stability. The complex, prepared by kneading method, was characterized in the solid state by differential scanning calorimetry and in aqueous solution using circular dichroism and NMR spectroscopy. The formation of 1:1 and 1:2 drug-Cyd complexes was hypothesized. Stability constants for both complexes were determined on the basis of an Ap-type phase solubility diagrams and evidenced a very high stability for the 1:1 complex. Thermodynamic parameters of the binding process showed the existence of classical hydrophobic interactions in the 1:1 complex with the formation of a less ordered system after complexation. An enthalpic contribution rather than an entropic one accompanied the association of the second Cyd molecule. DM-beta-Cyd was able to significantly increase water solubility of WIN 51711, from 0.000123 to 0.47142 mg/ml. Free drug shows a very low water stability, it is completely hydrolyzed after 36 h in PBS (pH 7.0), at 4 degrees C. In the presence of DM-beta-Cyd only a 10% of WIN 51711 was degraded, to the same conditions, after 12 days. DM-beta-Cyd increases the permeation of WIN 51711 across excised bovine nasal mucosa mounted on Franz cells, with respect to the free drug. Nevertheless, the permeation process had a lag time of 2 h so that the drug might assure its pharmacological activity on the outer surface of the mucosa. In vivo studies on rabbits evidenced that WIN 51711 is well tolerated, having no observable effect on the nasal mucosa following repeated administration.

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.

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.