Our previous studies show that chronic administration of L-arginine decreases cyclosporin-A-induced bone loss. The present study was designed to investigate whether a soy diet could prevent cyclosporin A-induced osteopenia and eventually improve the protective effect of L-arginine. Rats on soy diet were treated with cyclosporin-A, L-arginine, cyclosporin-A + L-arginine or saline. Control groups received a normal diet and the same pharmacological treatment. Our results show that a soy diet prevents osteopenia only in the spinal cord (+30%) and confirm the protective effect of L-arginine in cyclosporin-A-induced osteopenia in whole body, pelvis and spine of rats on a normal diet (+31%, +55%, +55%, respectively). Moreover these data show that the osteoprotective effect of L-arginine in the whole body, pelvis and spine improves in the case of soy diet (+60%, +72%, +89%, respectively). The results suggest that a soy diet exerts a positive effect in cyclosporin-A-induced osteopenia only in sites with high turn-over and improves the osteoprotective effect of L-arginine.

Derivatives of 1,3,4-thiadiazino[2,3-b]quinazoline 7, 9, 9a, 12, 12a, and 13 were prepared from the 3-amino-6-bromo-2,3-dihydro-2-thioxo-4-(1H)-quinazolinone (2) and its analogue without bromine. A series of the title derivatives with or without bromine was tested and the results of pharmacological screening are discussed.

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.

Previous studies indicate that blood levels of cyclosporin-A are increased by concomittant administration of grapefruit juice in healthy subjects and patients. It was suggested that grapefruit juice could inhibit the metabolism of cyclosporin-A by CYP3A4, the predominant cytochrome P450 enzyme in the gut wall and liver. However, up to date, the mechanism of action of grapefruit juice has not been conclusively identified and no work has been conducted in animals to quantify its effect on cyclosporin-A metabolism. This study compared the disposition of cyclosporin-A (5 mg/kg) coadministered with grapefruit juice, orange juice or water (10 ml/kg) in male Sprague-Dawley rats. Time to peak concentration was about 5 h for each group. Area under the blood concentration-time curve and peak concentration of cyclosporin-A were increased by 31% and 20%, respectively, with grapefruit juice (P < 0.05). The effects of grapefruit juice were not duplicated by orange juice which did not differ significantly from water for any of the parameters tested. These results confirm that grapefruit juice may act as an inhibitor of drug metabolism altering the disposition of concomittantly administered cyclosporin-A in rats. Nonetheless, it was demonstrated that, under appropriate experimental conditions, rats may be suitable models for in vivo investigation of the interaction mechanism between grapefruit juice and cyclosporin-A.

A number of phenylamides of 5-benzamidopyrazole-4-carboxylic acid were prepared in 50-80% yields from 1-phenyl (or methyl)-6-phenylpyrazolo[3,4-d]1,3-oxazin-4(1H)-ones and aniline derivatives. All the compounds were tested for their analgesic and antiinflammatory activities, as well as for their ulcerogenic potential and acute toxicity. Some derivatives, when compared to phenylbutazone, proved more active in the tests for analgesic and antiexudative activities, but less active in the carrageenin paw oedema test. The compounds proved to posses marginal or no ulcerogenic effect, as well as low systemic toxicity.

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.

Several new 1-methyl-5-[substituted-4-oxo-1,2,3-benzotriazin-3-yl] -1H-pyrazole-4-acetic acids and their ethyl ester derivatives were prepared. The compounds were tested for analgesic and antiinflammatory activities, acute toxicity, ulcerogenic effect, and as in vitro inhibitors of 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD), since it is claimed that the inhibition of such an enzyme predicts in vivo antiinflammatory activity. Some compounds were more active than phenylbutazone in the phenylbenzoquinone and acetic acid peritonitis tests, and equiactive to the same drug in the carrageenin paw edema test. All the compounds inhibited the 3 alpha-HSD, but no correlation was observed with the paw edema inhibition values. The compounds proved to possess marginal or no ulcerogenic effect, as well as low systemic toxicity.

Adrenomedullin intracerebroventricularly administered (0.1 to 20 ng/rat i.c.v.), showed significant gastroprotective activity in a dose-dependent manner. When the peptide was intravenously administered (1 to 1000 ng/kg i.v.) it did not show significant gastroprotective activity in the same test. The gastroprotective effect of the peptide (10 ng/rat) was abolished by bilateral adrenalectomy, by pretreatment with the β-adrenoceptor antagonist, propranolol (1 mg/kg i.p.), or by a calcitonin gene-related peptide (CGRP) receptor antagonist, CGRP-(8-37) fragment (1 or 10 ng/rat i.c.v.). This study showed that adrenomedullin is protective against reserpine-induced gastric lesions, that the action involves sympathetic nerve activity, and moreover interferes with CGRP receptors.

Subcutaneous administration of amylin (20 to 40 μg/kg) prevented, in a dose-dependent manner, reserpine- and serotonin-induced gastric damage, but the anti-ulcer effect was not present when lesions were induced by pylorus ligation. The protective effect of amylin was inhibited by pretreatment with capsaicin as well as CGRP-(8-37), a calcitonin gene-related peptide (CGRP) and amylin receptor antagonist, and was significantly reduced by domperidone, a dopamine D2 receptor antagonist, or neostigmine, an inhibitor of acetylcholinesterase. Our data suggest that the gastroprotective activity of amylin in some experimental models of gastric ulcers involves capsaicin-sensitive fibers and CGRP receptors. Moreover, the peptide interferes, at least in part, with the dopaminergic and parasympathetic systems.

Several peptide growth factors, including EGF, are known to protect endothelium from oxygen-related damage or ischemia-reperfusion, in vitro experiments show that such protective effect involves endogenous endothelium-related factors like nitric oxide and prostanoids. However, in vivo demonstrations of a possible role in related vascular diseases are lacking. In our experiments, human EGF and fraction C, a 3-10 kDa oligosaccharidic fraction from an aqueous extract of Triticum vulgare, known as growth promoters for several cell types including endothelial cells, were found protective against ischemic necrosis of the mouse tail induced by i.v. k-carrageenin plus endothelin-1. After i.p. injection, peak activities were observed at 10 micrograms/kg EGF and 2 mg/kg fraction C. Pretreatment with L-NAME reduced protection in a dose-dependent manner. Addition of indomethacin increased the effect of L-NAME, suggesting that both nitric oxide and eicosanoids are involved in the protective effect of EGF and fraction C.

Recent reports from our laboratory gave evidence showing that propionyl-L-carnitine (PLC), unlike L-carnitine (LC) and acetyl-L-carnitine (ALC), has anti-inflammatory activity in some models of vascular inflammation in rodents. The present paper shows that PLC (50 to 200 mg kg-1 i.p.) inhibits rat paw oedema induced by platelet activating factor (PAF), while LC and ALC, as well as indomethacin and phenylbutazone, are ineffective. The extent of the maximal inhibition produced by PLC at 200 mg kg-1 was comparable to that of betamethasone 0.05 mg kg-1 or sodium salicylate 100 mg kg-1. PLC inhibited also the early phase (1-2 h) of carrageenin-induced rat paw oedema, which is partly dependent on PAF release, but it was ineffective in the eicosanoid-dependent late phase (3-4 h) of the carrageenin oedema. We suggest that such anti-inflammatory activity of PLC may be due to various mechanisms converging on a stabilizing action upon biomembranes.

Two series of novel derivatives based on the thienopyrimidine and pyrimidoindole ring systems, both N-substituted in position 3, have been synthesized. The compounds were obtained by reaction of N-amino groups of 5,6-dimethyl-thieno[2,3-d]pyrimidin-2,4-dione and of 5H-pyrimido[5,4-b]indol-2,4-dione with aromatic aldehydes. Some of these substances showed an appreciable analgesic activity, a good antiinflammatory activity, a low acute toxicity with an optimal gastric tolerance.

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.

The dialkylamino-alkylation of 3H-pyridazino[4,5-b][1,4]benzothiazin-4(10H)-one-5,5-dioxide 5 produced the 3-dialkylaminoalkyl-derivatives 6. To the same compounds we arrived by selective reduction of the corresponding N-oxides 4, derived from the oxidation of the 3-dialkylaminoalkyl-3H-pyridazino[4,5-b][1,4]benzothiazin-4( 10H)-ones 3. Similarly, the oxidation of the 10-dialkylaminoalkyl analogues 8 afforded the corresponding derivatives 9. The synthesized compounds were tested, as hydrochlorides, for their analgesic and anti-inflammatory activities. The results showed that many of these compounds possess a very good analgesic activity, superior to that of phenylbutazone, apparently not related to the position and the peculiarities of the aminoalkylic side-chain. The anti-inflammatory activity was moderate, comparable only for 4 c to that of phenylbutazone. In the most active compounds a very low ulcerogenic potential and a high LD50 have been observed.

A number of new ethyl 1-methyl-5-[4-oxo-3(4H)-quinazolinyl]-1H-pyrazole-4-acetates substituted at the 2 position of the quinazolinone ring were prepared. The compounds were tested for analgesic and antiinflammatory activities, as well as for their acute toxicity and ulcerogenic effect. The 2-methyl, 2-ethyl and 2-phenyl derivatives proved to be more active than acetylsalicylic acid and phenylbutazone in the phenylbenzoquinone writhing test. The 2-methyl derivative was also as active as acetylsalicylic acid in the carrageenin paw oedema test. All the compounds showed very reduced ulcerogenic effects and systemic toxicity.

The anti-inflammatory activity of calcitonin gene-related peptide (CGRP) has been studied in cutaneous inflammation induced by croton oil (CO), arachidonic acid (AA), tetradecanoylphorbol acetate (TPA) or cantharidin (CA). Our results show that mouse ear inflammation induced by CO, AA or TPA is decreased by topical administration of CGRP, whereas that induced by CA is not affected. The dose-response and temporal analysis of CGRP effect show that the maximal activity is present at the dose of 30 pmol/ear and when administered 30 min after the irritating agent. Moreover, pretreatment with capsaicin is able to mimic the anti-inflammatory effect of exogenous CGRP, while simultaneous administration of CGRP and capsaicin produces a reduced response. Our results suggest that CGRP released from sensory.

Intramuscular administration of medprotine, a protein fraction of human placenta (30-300 kDa), produced dose-dependent and long lasting analgesia as evaluated by various analgesic tests in mice. Activity was found in a dose range of 0.05-0.6 mg/kg in the phenylbenzoquinone and acetic acid writhing tests and 1.5-5 mg/kg in the hot-plate test. In this latter model, medprotine enhanced morphine-induced analgesia. Pretreatment with naloxone antagonized the effect of medprotine in all assays. The antinociceptive response of medprotine was not modified after a ten day pretreatment and no overt withdrawal symptom could be observed after either interruption of chronic treatment or administration of a precipitating dose of naloxone. It is concluded that the analgesic activity of medprotine may be mediated through either the opiate receptors or activation of endogenous opioidergic systems.

The synthesis of some amidic derivatives of N-methyl-isoquinolin-1(2H)-one-4-carboxylic acid and of isocoumarin-4-carboxylic acid are reported. These compounds have been evaluated for analgesic, antiinflammatory and antipyretic activities. The central nervous system effects have been also investigated.

The effects of propionyl-L-carnitine (PLC) in various models of inflammation were studied in rats and mice. PLC (50-200 mg/kg i.p.) dose-dependently inhibited the granuloma pouch induced by croton oil in rats, but failed to inhibit either cotton pellet granuloma or carrageenin-induced paw oedema and peritonitis. PLC (100 mg/kg i.p.) significantly reduced mouse ear oedema induced by croton oil, tetradecanoylphorbol acetate and arachidonic acid; in these models, PLC concomitantly reduced plasma extravasation, as evaluated by the leakage of Evans blue. In all the tested models, L-carnitine and acetyl-L-carnitine were ineffective, suggesting a specific protective role of PLC in the vascular component of the inflammatory process.

Different classes of GABAergic drugs--baclofen, GABA, muscimol, Na-valproate, Mg-valproate and diazepam--were tested per os on ethanol-induced gastric lesions in rats. The GABAB agonist baclofen failed to affect gastric susceptibility to ethanol damage, while all the other compounds exerted a dose-dependent inhibition on haemorrhagic-necrotic lesions. This effect was not significantly reversed by the specific GABAA antagonist bicuculline, suggesting it to be independent from GABAA receptors. The blockade of prostaglandin synthesis by indomethacin significantly decreased the gastroprotective action of GABA, Na- and Mg-valproate, but did not antagonize the effect of muscimol and diazepam. Gastric juice volume and pH showed remarkable differences between the various treatments.