Vincenza Maria Catena Cutuli

Synthesis and pharmacological study of ethyl 1-methyl-5-(substituted 3,4-dihydro-4-oxoquinazolin-3-yl)-1H-pyrazole-4-acetates.

Several new ethyl 1-methyl-5-(substituted 3,4-dihydro-4-oxoquinazolin-3-yl)-1H-pyrazole-4-acetates 2, substituted at 2 and, alternatively at, 6, 7 or 8 positions of the quinazolinone nucleus, were synthesised. The compounds were screened for their analgesic and antiinflammatory activities, acute toxicity and ulcerogenic effect. Substitution in the benzene moiety of the quinazolinone ring did not show any advantage for the analgesic activity, whereas it improved in some cases the antiinflammatory activity. Some compounds showed appreciable antiinflammatory activity and, at the same time, very low ulcerogenic index.

Synthesis and pharmacological activities of novel 3-(isoxazol-3-yl)-quinazolin-4(3H)-one derivatives.

Several new 3‐(isoxazol‐3‐yl)‐quinazolin‐4(3H)‐one derivatives were synthesized and tested for their analgesic and antiinflammatory activities, as well as for their acute toxicity and ulcerogenic effect. A few compounds were as active as phenylbutazone in the writhing and acetic acid peritonitis tests. They had a very low ulcerogenic effect.

Amylin given by central or peripheral routes decreases gastric emptying and intestinal transit in the rat

The effect of rat amylin on gastric emptying and intestinal transit in the rat was examined. Amylin administered intracerebroventricularly (1, 2, 2.5 or 4 μg/rat) produced the maximal decrease in gastric emptying and intestinal transit at the dose of 2.5 μg/rat. Higher doses produced a lower effect. Peripheral administration (25, 50 or 100 μg/kg) produced dose-dependent effects. Pre-treatment with neostigmine blocked the effect of amylin when it was centrally injected, while the effect of amylin given peripherally was partially reduced. Pre-treatment with domperidone decreased the inhibitory effect of peripherally injected amylin, but no effect was observed when the peptide was centrally injected.

L-arginine prevents bone loss and bone collagen breakdown in cyclosporin A-treated rats.

Cyclosporin A is implicated in the pathogenesis of post-transplantation bone disease. Because of recent evidence that cyclosporin A may cause renal and cardiovascular toxicity by inhibiting nitric oxide (NO) activity, and that NO slows bone remodeling and bone loss in animal and human studies, we investigated a possible link between NO production and beneficial effects on bone health in cyclosporin A-treated rats. Thirty-six 10-week-old male rats were assigned to six groups of six animals each, and treated for 4 weeks with: vehicle; cyclosporin A; L-arginine; N(G)-nitro-L-arginine methylester (L-NAME, a general inhibitor of NO synthase activity); a combination of cyclosporin A+L-arginine; and a combination of cyclosporin A+L-NAME. Whole body and regional (spine and pelvis) bone mineral content of rats were measured under basal conditions and at the end of the treatment period by dual-energy X-ray absorptiometry (DXA) scanning. Femur weights and serum concentrations of pyridinoline, a reliable marker of bone resorption, were measured at the end of the study period. Cyclosporin A-, L-NAME-, and cyclosporin A+L-NAME-treated rats had significantly lower bone mineral content and femur weights, and significantly higher pyridinoline levels than did control animals. The administration of L-arginine appeared to prevent bone loss caused by cyclosporin A, suggesting that this amino acid, which can be converted to produce NO, might prove useful in preventing disturbed bone modeling and inhibition of bone growth associated with cyclosporin A therapy.

Anti-inflammatory activity of amylin and CGRP in different experimental models of inflammation

The anti-inflammatory activity of amylin was studied in different models of inflammation, and compared to that of CGRP. Both peptides were active against mouse ear oedema induced by croton oil and acetic acid-induced peritonitis in the rat. CGRP was more potent than amylin in both models. Pretreatment with CGRP 8-37 fragment blocked the anti-inflammatory activity of both peptides in croton oil ear oedema. No anti-inflammatory activity was evidenced against serotonin-induced rat paw oedema and plasma protein extravasation induced by dextran in rat skin. Our results suggest that amylin exerts anti-inflammatory activity only in inflammatory models characterized by a vascular component. This effect appears to be mediated by the involvement of CGRP receptors.

Antiinflammatory activity of adrenomedullin in the acetic acid peritonitis in rats.

The antiinflammatory effect of ADM was studied in different models of inflammation and compared to the one of CGRP. Peptides were active against acetic acid-induced peritonitis in the rats. ADM and CGRP exerted the antiinflammatory effect at different doses, 400 and 20 ng/kg respectively, but with different efficacy (ADM >CGRP). This effect was blocked by pretreatment with CGRP (8-37) fragment or with L-NAME. No antiinflammatory activity was evidenced against serotonin- or carrageenin-induced rat paw edema. Our data suggest that ADM exerts antiinflammatory activity in the model characterized by a vascular component. This effect involves CGRP receptors and appears to be mediated by nitric oxide system.

Synthesis of new thienopyrimidobenzothiazoles and thienopyrimidobenzoxazoles with analgesic and antiinflammatory properties

Abstract As an extension of research on analgesic and antiinflammatory compounds, a series of substituted analogues based on the novel 4H-thieno[2′,3′:4,5]pyrimido[2,1-b]benzothiazole and 4H-thieno[2′,3′:4,5]pyrimido[2,1-b]benzoxazole ring systems was synthesized. The compounds were obtained by reaction of 2-amino-3-carbethoxy-4,5-disubstituted thiophenes with 2-chlorobenzothiazole and 2-chlorobenzoxazole, respectively. Starting from 2-carbomethoxy-3-aminothiophene, 11H-thieno[3′,2′:4,5]pyrimido[2,1-b]-benzothiazol-11-one and 11H-thieno[3′,2′:4,5]pyrimido[2,1-b]benzoxazol-11-one were prepared in the same way. Synthesized compounds were evaluated for their potential analgesic activity in phenylquinone-induced writhing test in mice and for their potential antiinflammatory activity in carrageenan-induced rat-paw oedema test, in acetic-acid peritonitis assay and in croton oil-induced mouse-ear oedema test. 9,10,11,12-Tetrahydro-12H-benzothieno[2′,3′:4,5]pyrimido[2,1-b]benzoxazol-12-one 12 was the most active derivative in the series in all performed tests. It showed remarkable analgesic and antiinflammatory activities associated with an excellent gastric tolerance.

Protective effects of calcitonin gene-related peptide in different experimental models of gastric ulcers

Intravenous administration of calcitonin gene-related peptide (CGRP) prevented in a dose-dependent manner reserpine-induced gastric mucosal damage, but failed to affect the lesions produced by ethanol administration. In pylorus-ligated rats, CGRP significantly reduced gastric volume, total acid and peptic activity output as well as ulcer formation. These protective effects of CGRP were not present when rats were pretreated with cysteamine. Our data suggest that CGRP exerts its antisecretory and antiulcer activity, at least in part, by interfering with somatostatin transmission.

Pyrazolothiazolopyrimidine derivatives as a novel class of anti-inflammatory or antinociceptive agents: synthesis, structural characterization and pharmacological evaluation☆

Abstract As a part of a research program on anti-inflammatory-analgesic compounds, pyrazolothiazolopyrimidines 5a-f and 5g-i were prepared by cyclodehydration in 98% H 2 SO 4 or PPA of the corresponding 6-thioketomethylene-substituted-4-hydroxy-pyrazolo[3,4- d ]pyrimidines 2a-i and 2g-i . The results of the pharmacological in vivo screening indicate an interesting dissociation of the analgesic from the anti-inflammatory activity depending on aromatic or aliphatic substitution at the C4 of the thiazole ring. Analgesic activity was not associated with any narcotic effect; in addition, all the active compounds showed a remarkable systemic and gastric tolerance. This indicated a mode of action different from that of the classical nonsteroidal anti-inflammatory drugs, acting on prostaglandin biosynthesis. To clarify the mechanism or the mechanisms underlying the pharmacological activity of these and other closely related compounds, we initiated a ‘file chemical approach’ to various systems involved in the inflammatory process. At present, some of the more active in vivo compounds tested as substance P antagonists showed a moderate and possibly non-specific effect on NK 1 and NK 2 receptors.

Gastroprotective effect of adrenomedullin administered subcutaneously in the rat

Subcutaneous injections of adrenomedullin prevented reserpine-induced gastric mucosal damage in a dose-dependent manner (1-1000 ng/kg), but did not interfere with the lesions produced by ethanol administration. In pylorus-ligated rats adrenomedullin significantly reduced gastric volume, total and free acid output as well as ulcer formation. The gastroprotective activity of adrenomedullin was not present in rats pretreated with cysteamine. These results suggest that adrenomedullin exerts its antiulcer effect, when it is administered subcutaneously (s.c.), probably by a mechanism which involves somatostatin related transmission.