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Biomedical subjects

P Del Soldato

Publications and source records attributed to P Del Soldato.

At least 19 recordsLinked to original sources

Ultrastructural investigations on protective effects of NCX 4016 (nitroaspirin) on macrovascular endothelium in diabetic Wistar rats.

The effect of a nitric oxide-donating aspirin derivative, 2-acetoxy-benzoate 3-(nitroxy-methyl)phenyl ester (NCX 4016), and aspirin on the aortic endothelium of diabetic rats was investigated by using scanning and transmission electron microscopy. Control and streptozotocin-treated rats were used. Metabolic control was assessed by measuring blood and urine metabolites, and 24-h urine volume. The ultrastructural study was performed after 7 weeks of diabetes and 6 weeks of therapy. Streptozotocin treatment induced a persistent hyperglycemia which was not influenced by the pharmacological treatments. Values of blood metabolites were in line with the diabetic status. Both scanning and transmission electron microscopy revealed that aortic endothelium was severely damaged in all diabetic rats except for the NCX 4016 treated ones. Our data document the protective effects of NCX 4016 on the vascular endothelium of diabetic rats. Since aspirin had no protective action, NCX 4016 may have exerted its beneficial action by releasing nitric oxide.

Animals↗

The flurbiprofen derivatives HCT1026 and HCT1027 inhibit bone resorption by a mechanism independent of COX inhibition and nitric oxide production.

Prostaglandins and nitric oxide both modulate bone resorption and bone formation. We previously reported that a nitrosylated derivative of flurbiprofen, termed HCT1026, exerted inhibitory effects on osteoclastic bone resorption, which could not be reproduced by combining the parent compound with nitric oxide (NO) donors. The aim of this study was to investigate the mechanism by which HCT1026 inhibits bone resorption. We compared the effects of flurbiprofen and HCT1026 on osteoclast and osteoblast activity with those of HCT1027--an analogue of HCT1026, which lacks an NO-donating moiety. We found that HCT1026 and HCT1027 inhibited bone resorption in interleukin (IL)-1-stimulated murine osteoblast-bone marrow cocultures, with half-maximal effects (IC50) at 20 +/- 5 microM for HCT1026 and 25 +/- 6 microM for HCT1027 compared with 399 +/- 25 microM for flurbiprofen (P < 0.0001). These differences were unrelated to cyclooxygenase (COX) inhibition since HCT1026 and HCT1027 were about seven to eight times less potent than flurbiprofen at inhibiting COX-1 activity and half as potent at inhibiting COX-2 activity. Further studies showed that HCT1026 and HCT1027 activated caspase-3 in rabbit osteoclasts and promoted osteoclast apoptosis, as assessed by nuclear morphology and TUNEL assays. We conclude that HCT1026 and HCT1027 inhibit osteoclast formation and activity by a mechanism that is independent of NO production and COX inhibition. This raises the possibility that both compounds interact with a novel molecular target expressed on osteoclasts to promote apoptosis and inhibit bone resorption. This demonstrates that HCT1026 and derivatives could represent a novel class of antiresorptive drugs with therapeutic value in the treatment of bone diseases associated with accelerated bone loss due to osteoclast activation.

Animals↗

Addition of nitric oxide via nitroflurbiprofen enhances the material properties of early healing of young rat Achilles tendons.

OBJECTIVE AND DESIGN: To determine if the addition of nitric oxide (NO) via nitroflurbiprofen (NO-flurbiprofen) would enhance rat Achilles tendon healing. MATERIALS AND METHODS: Sixty-five male Sprague-Dawley rats were randomly divided into NO-flurbiprofen, flurbiprofen and vehicle groups, given drugs or vehicle subcutaneously, and their right Achilles tendon divided. Histological assessment was carried out at day 5, 10, and 15 post-operation. Healing tendon biomechanical properties and hydroxyproline content were measured at day 10. RESULTS: The healing Achilles tendon from the NO-flurbiprofen and flurbiprofen groups showed a better organization of extracellular collagenous matrix than that from the vehicle group. Flurbiprofen and NO-flurbiprofen decreased healing tendon cross-sectional area by 30% and 20%. This reduction was accompanied by a decreased failure load in the flurbiprofen group, but not the NO-flurbiprofen group. NO-flubiprofen prevented the reduction of body weight gain observed in the flubiprofen group. CONCLUSION: Both flurbiprofen and NO-flurbiprofen promoted better collagen reorganization during tendon healing. NO-flurbiprofen further improved tendon healing by increasing tendon stress and reducing the side effects (body weight loss) of flurbiprofen. The enhanced tendon healing by NO-flurbiprofen is likely due to the release of NO from the compound.

Achilles Tendon↗

The effects of sham and full spinalization on the antinociceptive effects of NCX-701 (nitroparacetamol) in monoarthritic rats.

Nitric oxide (NO)-releasing NSAIDs have been shown to be safer and more potent as antinociceptive and anti-inflammatory agents than their parent compounds. NCX-701 (nitroparacetamol), in contrast to paracetamol, is an effective antinociceptive drug in normal animals but their effectiveness in monoarthritis has not been compared. We have now investigated this question by comparing the antinociceptive effects of i.v. NCX-701 and paracetamol in monoarthritic rats under alpha-chloralose anesthesia. The influence of spinalization on the effects of NCX-701 was also studied. NCX-701 and paracetamol were equipotent in reducing single motor unit responses to noxious mechanical stimulation, ID50s of 320+/-1.2 and 305+/-1.2 micromol/kg, respectively. The mechanism of action seems to be different since NCX-701, but not paracetamol, reduced wind-up. This effect suggests a central action, probably within the spinal cord. Sham spinalization reduced the effect of NCX-701 on nociceptive responses drastically. In spinalized animals, however, the effect was similar to that observed in intact animals, indicating a strong effect of NCX-701 at spinal sites, which counterbalances the decrease in the activity induced by the surgery. We conclude that NCX-701 is an effective antinociceptive drug in arthritic animals, with a mechanism of action located in the spinal cord, and different to that of paracetamol.

Acetaminophen↗

NO-aspirin: mechanism of action and gastrointestinal safety.

Nitric oxide-releasing aspirins are new chemical entities obtained by adding a nitric oxide-releasing moiety to aspirin. NCX-4016 is the prototype of this family of molecules. NCX-4016 consists of the parent molecule (aspirin) linked to a 'spacer' via an ester linkage, which is in turn connected to a nitric oxide-releasing moiety. Both aspirin and nitric oxide moieties of NCX-4016 contribute to its effectiveness, the latter occurring via both cyclic guanosyl monophosphate-dependent and -independent mechanisms. In vitro studies have shown that NCX-4016 inhibits platelet aggregation induced by aspirin-sensitive (arachidonic acid) and aspirin-insensitive (thrombin) agonist. In contrast to aspirin, NCX-4016 exerts a multilevel regulation of inflammatory target, including caspase-1 and NF-kappaB. This broad spectrum of activities translates to an increased potency of this drug in modulating cardiovascular inflammation. Human studies have shown, that while nitric oxide-aspirin maintains its anti-thrombotic activity, it spares the gastrointestinal tract. Indeed, a 7-day course of NCX-4016 results in 90% reduction of gastric damage caused by equimolar doses of aspirin. Further studies are ongoing to define whether this superior anti-inflammatory and anti-thrombotic profile translates in clinical benefits in patients with cardiovascular diseases.

Anti-Inflammatory Agents, Non-Steroidal↗

Effects of non-steroidal anti-inflammatory drugs on cyclo-oxygenase and lipoxygenase activity in whole blood from aspirin-sensitive asthmatics vs healthy donors.

1. Cyclo-oxygenase (COX) and lipoxygenase (LO) share a common substrate, arachidonic acid. Aspirin and related drugs inhibit COX activity. In a subset of patients with asthma aspirin induces clinical symptoms associated with increased levels of certain LO products, a phenomenon known as aspirin-sensitive asthma. The pharmacological pathways regulating such responses are not known. 2. Here COX-1 and LO activity were measured respectively by the formation of thromboxane B(2) (TXB(2)) or leukotrienes (LT) C(4), D(4) and E(4) in whole blood stimulated with A23187. COX-2 activity was measured by the formation of prostaglandin E(2) (PGE(2)) in blood stimulated with lipopolysaccharide (LPS) for 18 h. 3. No differences in the levels of COX-1, COX-2 or LO products or the potency of drugs were found in blood from aspirin sensitive vs aspirin tolerant patients. Aspirin, indomethacin and nimesulide inhibited COX-1 activity, without altering LO activity. Indomethacin, nimesulide and the COX-2 selective inhibitor DFP [5,5-dimethyl-3-(2-isopropoxy)-4-(4-methanesulfonylphenyl)-2(5H)-furanone] inhibited COX-2 activity. NO-aspirin, like aspirin inhibited COX-1 activity in blood from both groups. However, NO-aspirin also reduced LO activity in the blood from both patient groups. Sodium salicylate was an ineffective inhibitor of COX-1, COX-2 or LO activity in blood from both aspirin-sensitive and tolerant patients. 4. Thus, when COX activity in the blood of aspirin-sensitive asthmatics is blocked there is no associated increase in LO products. Moreover, NO-aspirin, unlike other NSAIDs tested, inhibited LO activity in the blood from both aspirin sensitive and aspirin tolerant individuals. This suggests that NO-aspirin may be better tolerated than aspirin by aspirin-sensitive asthmatics.

Anti-Inflammatory Agents, Non-Steroidal↗

Nitric-oxide releasing molecules: a new class of drugs with several major indications.

Nitric oxide (NO) deficiency has been implicated in many pathological and physiological processes within the mammalian body providing a plausible biologic basis for the use of NO replacement therapy in these conditions. Exogenous NO sources may hopefully constitute a powerful way to supplement NO when the body cannot generate enough for normal biological functions. This theory has opened up the possibility of designing new drugs that are capable of delivering NO into tissues and the bloodstream in a sustained and controlled manner. This objective has been reached by grafting an organic nitrate structure onto existing molecules with various spacers such as aliphatic or aromatic chain, with different degree of complexity. This approach has led to the synthesis of several new chemical entities in various pharmacological classes, whose profile seems to challenge the parent drug not only on the basis of new pharmacological properties but also on a better toxicological and safety profile. In this article, general aspects on NO and NO donors are reviewed. Major focus is placed upon recent developments of novel NO donors, NO releasing device(s) as well as innovative improvements to conventional NO donors. Several examples are given in some important therapeutic indications such as cardiovascular diseases (NO-aspirin), pain and inflammation (NO-paracetamol), osteoporosis and urinary incontinence (NO flurbiprofen with aliphatic spacer), Alzheimer s disease (NO-flurbiprofen with anti-oxidant spacer), respiratory disorders (NO-steroids).

Animals↗

Antiproliferative effects of nitrosulindac on human colon adenocarcinoma cell lines.

Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the incidence of colon cancer, but their use is limited by toxicity in the gastrointestinal tract. The coupling of a nitric oxide-releasing moiety to NSAIDs strongly reduces these side effects. We demonstrated that the NO-releasing sulindac (nitrosulindac) has much more potent effects on colon adenocarcinoma cell lines compared to sulindac. Moreover, it could inhibit the growth of cells in soft agar experiments, demonstrating the antineoplastic activity at low concentration of nitrosulindac. However, this reduction in the growth of colon cancer cells seemed to be independent of the classical apoptosis pathway and could be explained by a cytostatic effect. Nitrosulindac caused a light perturbation of the cell cycle parameters not linked to a modification of the levels of p21 or the proliferating cell nuclear antigen. Moreover, neither sulindac, nor nitrosulindac, were able to inhibit the NF-kappa B pathway. These data suggested that nitrosulindac could be a better solution compared to other NSAIDs in the treatment of colon cancer.

Adenocarcinoma↗

Nitro-aspirin (NCX4016) reduces brain damage induced by focal cerebral ischemia in the rat.

The potential neuroprotective effects of the novel nitro-derivate of aspirin (NCX4016) on permanent focal cerebral ischemia in spontaneously hypertensive rats (SHRs) was investigated. Reference compounds were acetylsalicilic acid (ASA) and FK506 (tacrolimus). Ten minutes after surgery, SHRs were randomly divided into four groups of ten, pharmacologically treated and sacrificed 24 h after treatment. Brains were removed and processed to measure infarct volume, 70 kDa heat shock protein (hsp70), glial fibrillary acidic protein (GFAP) and vimentin (Vim) immunoreactivity (IR), and apoptosis using terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-digoxigenin nick end-labeling (TUNEL) assay. NCX-4016 significantly reduced total infarct volume compared to ASA (-20%, P < 0.05), FK506 (-18%, P < 0.05) and vehicle treatment (-20%, P < 0.05). Experimental groups did not differ in hsp70-IR and GFAP-IR. Conversely, hyperplastic astrocytes, measured by Vim-IR, were significantly lower in NCX-4016 than in the vehicle group (-36%, P<0.01). TUNEL assay indicated a significantly lower degree of apoptosis in NCX-4016 group than vehicle in both the homolateral (-27%, P < 0.01) and contralateral hemisphere (-29%, P < 0.05). These findings indicate that NO release associated with aspirin confers neuroprotective effects against ischemic injury.

Animals↗

Effects of nitric oxide-releasing aspirin versus aspirin on restenosis in hypercholesterolemic mice.

Restenosis is due to neointimal hyperplasia, which occurs in the coronary artery after percutaneous transluminal coronary angioplasty (PTCA). During restenosis, an impairment of nitric oxide (NO)-dependent pathways may occur. Concomitant hypercholesterolemia may exacerbate restenosis in patients undergoing PTCA. Here, we show that a NO-releasing aspirin derivative (NCX-4016) reduces the degree of restenosis after balloon angioplasty in low-density lipoprotein receptor-deficient mice and this effect is associated with reduced vascular smooth muscle cell (VSMC) proliferation and macrophage deposition at the site of injury. Drugs were administered following both therapeutic or preventive protocols. We demonstrate that NCX-4016 is effective both in prevention and treatment of restenosis in the presence of hypercholesterolemia. These data indicate that impairment of NO-dependent mechanisms may be involved in the development of restenosis in hypercholesterolemic mice. Although experimental models of restenosis may not reflect restenosis in humans in all details, we suggest that a NO-releasing aspirin derivative could be an effective drug in reducing restenosis following PTCA, especially in the presence of hypercholesterolemia and/or gastrointestinal damage.

Animals↗

An NO derivative of ursodeoxycholic acid protects against Fas-mediated liver injury by inhibiting caspase activity.

Caspases are key mediators in liver inflammation and apoptosis. In the present study we provide evidence that a nitric oxide (NO) derivative of ursodeoxycholic acid (UDCA), NCX-1000 ([2-(acetyloxy)benzoic acid 3-(nitrooxymethyl)phenyl ester]), protects against liver damage in murine models of autoimmune hepatitis induced by i.v. injection of Con A or a Fas agonistic antibody, Jo2. Con A administration causes CD4(+) T lymphocytes to accumulate in the liver and up-regulates FasL expression, resulting in FasL-mediated cytotoxicity. Cotreating mice with NCX-1000, but not with UDCA, protected against liver damage induced by Con A and Jo2, inhibited IL-1beta, IL-18, and IFN-gamma release and caspase 3, 8, and 9 activation. Studies on HepG2 cells demonstrated that NCX-1000, but not UDCA, directly prevented multiple caspase activation induced by Jo2. Incubating HepG2 cells with NCX-1000 resulted in intracellular NO formation and a DTT-reversible inhibition of proapoptotic caspases, suggesting that cysteine S-nitrosylation was the main mechanism responsible for caspase inhibition. Collectively, these data suggest that NCX-1000 protects against T helper 1-mediated liver injury by inhibiting both the proapoptotic and the proinflammatory branches of the caspase superfamily.

Animals↗

Inhibition of bone resorption in vitro and prevention of ovariectomy-induced bone loss in vivo by flurbiprofen nitroxybutylester (HCT1026).

OBJECTIVE: Inhibitors of prostaglandin production, such as nonsteroidal antiinflammatory drugs (NSAIDs), and pharmacologic nitric oxide (NO) donors, such as organic nitrates, have been suggested to protect against bone loss in both humans and experimental animals. Recently, a new class of nitrosylated NSAID (known as NO-NSAIDs) has been developed, which combines the properties of a NO donor with those of a cyclooxygenase (COX) inhibitor. This study investigated the effects of one of these compounds, flurbiprofen nitroxybutylester (HCT1026), on bone metabolism in vitro and in vivo. METHODS: The effects of HCT1026 on osteoclast formation and resorption were determined in vitro using cocultures of primary mouse osteoblasts and osteoclasts. The effect of HCT1026 in vivo was assessed using a mouse model of ovariectomy-induced bone loss. RESULTS: HCT1026 was significantly more efficacious than the parent compound, flurbiprofen, at inhibiting osteoclast formation and bone resorption in vitro, and these effects could not be reproduced by combinations of flurbiprofen with a variety of NO donors. Studies in vivo showed that HCT1026 protected against ovariectomy-induced bone loss by inhibiting osteoclastic bone resorption, whereas flurbiprofen at similar concentrations was ineffective. CONCLUSION: These data indicate that HCT1026 is a potent inhibitor of bone resorption in vitro and protects against ovariectomy-induced bone loss in vivo by a novel mechanism that appears to be distinct from its NO donor properties and from its inhibitory effects on COX activity. We conclude that HCT1026 may be of clinical value in the prevention and treatment of inflammatory diseases such as rheumatoid arthritis, which are characterized by joint inflammation as well as periarticular and systemic bone loss.

Animals↗

Aortic hyporeactivity to norepinephrine induced by lipopolysaccharide in cirrhotic rats: beneficial effects of a non-steroidal anti-inflammatory drug coupled with a nitric oxide donor.

BACKGROUND AND AIMS: Cirrhosis is associated with a hyperdynamic syndrome and arterial vasodilation that is related to nitric oxide (NO) synthase 3 overactivity. Septic shock is frequently associated with cirrhosis and with a vascular induction of NO synthase 2. The aims of this study were to compare the effects of lipopolysaccharide (LPS) in normal and cirrhotic rats, and to test the effects of a nonsteroidal anti-inflammatory drug (NSAID) coupled with a (NO) donor. METHODS: Cirrhotic rats received NO-flurbiprofen, flurbiprofen or vehicle followed by LPS or placebo 15 min later. The heart rate and mean arterial pressure of rats were monitered for 5 h. Thoracic aortic rings were removed and contracted with the use of norepinephrine. Nitric oxide synthase activity was measured in the aorta and stomach of cirrhotic rats. RESULTS: Arterial pressure decreased in cirrhotic rats in the vehicle/LPS and flurbiprofen/LPS groups. After LPS administration, the heart rate of rats increased in all groups. In the aortic rings, LPS induced hyporeactivity to norepinephrine in all groups except the NO-flurbiprofen group. This hyporeactivity was abolished after preincubation with Nw-nitro-L-arginine (L-NNA). Nw-nitro-L-arginine had no effect on norepinephrine-induced vasoconstriction in the NO-flurbiprofen/LPS group. Nitric oxide synthase 2 activity in the stomach and aorta of cirrhotic rats was increased in each group except in the NO-flurbiprofen group after LPS administration. Pretreatment with NO NSAID prevented aortic hyporeactivity to norepinephrine in cirrhotic rats treated with LPS as it probably inhibited the NO synthase 2 induction. CONCLUSIONS: These findings suggest that NO-flurbiprofen has a beneficial hemodynamic effect in cirrhotic rats and may help to prevent LPS aortic hyporeactivity.

Analysis of Variance↗

NO-mesalamine protects colonic epithelial cells against apoptotic damage induced by proinflammatory cytokines.

The activation of a self-amplifying cascade of caspases, of which caspase-8 is the apical protease, mediates Fas-, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-, and TNF-alpha-induced apoptosis in colon cell lines. Nitric oxide (NO) protects from apoptosis induced by Fas and TNF-alpha. We examined whether NCX-456, an NO-releasing derivative of mesalamine, protects colon epithelial cells from cytokine-induced apoptosis. Caco-2 and HT-29 cell lines express death factor receptors and are driven to apoptosis in response to incubation with Fas-agonistic antibody, TNF-alpha/interferon-gamma, and TRAIL. The two novel observations reported here are that 1) cotreatment of cells with NCX-456, but not mesalamine, resulted in concentration-dependent protection against death factor-induced apoptosis and inhibition of caspase activity, and 2) exposure to dithiothreitol, an agent that effectively removes NO from thiol groups, resulted in a 70% recovery of caspase activity, which is consistent with S-nitrosation as a major mechanism for caspase inactivation. These data suggest that caspase S-nitrosation represents a mechanism for protection of colonic mucosal epithelial cells from death factor-induced death.

Aminosalicylic Acids↗

Mechanisms to prevent the toxicity of chronic neuroinflammation on forebrain cholinergic neurons.

Inflammatory processes may play an important role in the degeneration of basal forebrain cholinergic cells Alzheimer's disease. We infused the proinflammagen lipopolysaccharide into the basal forebrain of young rats and determined whether the chronic administration of two novel non-steroidal anti-inflammatory drugs or a pan-caspase synthesis inhibitor, z-Val-Ala-Asp(OMe)-fluoromethyl ketone (zVAD), could provide neuroprotection from the cytotoxic effects of the neuroinflammation. Chronic lipopolysaccharide infusions decreased choline acetyltransferase activity and increased the number of activated microglia within the basal forebrain region. The level of caspases 3, 8 and 9 was increased in ventral caudate/putamen. Non-steroidal anti-inflammatory drug therapy attenuated the toxicity of the inflammation upon cholinergic cells and reduced caspases 3, 8 and 9 activity in the caudate/putamen. zVAD treatment significantly decreased the levels of caspases 3, 8 and 9 but did not provide neuroprotection for the cholinergic neurons. These results suggest that prostaglandins contribute to the degeneration of forebrain cholinergic neurons in Alzheimer's disease.

Amino Acid Chloromethyl Ketones↗

Prevention of pulmonary thromboembolism by NCX 4016, a nitric oxide-releasing aspirin.

We studied the antithrombotic activity of 2-acetoxybenzoate 2-[1-nitroxy-methyl]-phenyl ester (NCX 4016), a novel nitric oxide (NO)-releasing aspirin derivative, in vivo in different animal models of platelet-dependent and independent pulmonary thromboembolism and compared it with that of aspirin. NCX 4016 protected mice from death induced by the intravenous (i.v.) injection of collagen plus epinephrine, of 9,11-dideoxy-11alpha, 9alpha-epoxymethano-prostaglandin F(2alpha) (U46619) and of thrombin while aspirin was only active against collagen plus epinephrine. The drop in platelet count and number of lung emboli were reduced by NCX 4016 more effectively than aspirin. NCX 4016 protected mice also from mechanical pulmonary embolism (i.v. injection of hardened rat red blood cells) while aspirin was ineffective. In rabbits, NCX 4016 significantly reduced the accumulation of [111In]oxine-labeled platelets in the pulmonary vasculature induced by collagen and by thrombin while aspirin produced reductions which were significant only versus collagen. In conclusion, NCX 4016 exerts a more pronounced antithrombotic activity than aspirin in vivo in two different animal species, largely due to a deeper inhibitory effect on platelets. NCX 4016 may represent a better antithrombotic agent than aspirin.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

NO-aspirin protects from T cell-mediated liver injury by inhibiting caspase-dependent processing of Th1-like cytokines.

BACKGROUND & AIMS: Concanavalin A (con A)-induced hepatitis is an immunomediated disease in which assembly of CD4(+) T cells and T helper (Th)1-like cytokines causes Fas-mediated liver cell death. Nitric oxide (NO) modulates Th1 response in vitro. NCX-4016 is an NO-aspirin derivative that spares the gastrointestinal tract and shares molecular targets with NO. The aim of this study was to investigate whether this NO-aspirin modulates Th1-like response induced by con A. METHODS: BALB/c mice were injected with 0.3 mg con A per mouse alone or in combination with NO-aspirin (18-100 mg/kg) or aspirin (10-55 mg/kg). RESULTS: NO-aspirin, but not aspirin, caused a dose-dependent protection against liver damage induced by con A. At a dose of 100 mg/kg, NO-aspirin caused a 40%-80% reduction of interleukin (IL)-1beta, IL-12, IL-18, interferon (IFN)-gamma, and tumor necrosis factor alpha production without affecting cytokine messenger RNA expression. NO-aspirin prevented Fas, Fas ligand, and IL-2 receptor up-regulation on spleen lymphocytes and Fas ligand on hepatocytes and caused the S-nitrosylation/inhibition of IL-1beta-converting enzyme-like cysteine proteases (caspases) involved in the processing and maturation of IL-1beta and IL-18. IL-18 immunoneutralization prevented IFN-gamma release and protected from liver injury induced by con A. In contrast to a selective caspase 1 inhibitor, zVAD.FMK, a pancaspase inhibitor, prevented IFN-gamma release and protected the liver from injury. CONCLUSIONS: Th1-like response induced by con A is mediated by IL-18 and requires activation of multiple caspases. NCX-4016 causes the S-nitrosylation/inhibition of caspases involved in cytokine production. Inhibition of Th1-like response is a new anti-inflammatory mechanism of action of NO-aspirin.

Amino Acid Chloromethyl Ketones↗

21-NO-prednisolone is a novel nitric oxide-releasing derivative of prednisolone with enhanced anti-inflammatory properties.

1. Anti-inflammatory effects of a novel derivative of the glucocorticoid prednisolone were investigated. NCX-1015 (prednisolone 21-[(4'-nitrooxymethyl)benzoate]) incubation in human platelet-rich plasma produced a time (0 - 60 min) and concentration (3 - 300 microM) dependent release of nitrite, that was mirrored by accumulation of cyclic guanosine monophosphate in the human platelets. Intraperitoneal injection of NCX-1015 to mice (up to 27.7 micromol kg(-1)) produced nitrite accumulation in the peritoneal cavity maximal at 60 min. 2. NCX-1015 dose-dependently induced the steroid sensitive cell surface marker CD163 in human peripheral blood mononuclear cells (PBMCs). NCX-1015 was more potent than prednisolone in inducing CD163. Similarly, lipopolysaccharide induced interleukin-1 beta release from these cells was inhibited by NCX-1015 with higher potency than prednisolone. 3. In the zymosan peritonitis model, NCX-1015 was more active than prednisolone in suppressing neutrophil extravasation (ED(50) of 5.5 and 25.8 micromol kg(-1), respectively), nitrite accumulation (ED(50) of 1.38 and 22.2 micromol kg(-1), respectively) and release of the chemokine KC (ED(50) of 5.5 and 27.7 micromol kg(-1), respectively) as determined at the 4 h time-point. No differences were measured for the levels of interleukin-1 beta or prostaglandin E(2). NCX-1015 administered orally was also found to be equally active. Co-administration of the nitric oxide donors NOC-18 ((z)-1-[(2-aminoethyl)-N-(2-aminoethyl)amino] diazen-1-ium-1, 2-diolate; 7.9 micromol kg(-1)) or sodium nitroprusside (13.8 micromol kg(-1)) with prednisolone resulted in an additive anti-migratory action. 4. In a chronic model of granulomatous tissue inflammation, administration of NCX-1015 (13.9 micromol kg(-1)) from day 1 (i.e. after induction of inflammation) was more effective than prednisolone in reducing the granuloma dry weight, and this was associated to a lower anti-angiogenic effect. 5. In conclusion we show that NCX-1015 is more potent than prednisolone in controlling several, though not all, parameters of acute and chronic inflammation, and propose that this effect may be due to a co-operation between the steroid moiety and nitric oxide or related species released in biological fluids. Whereas this aspect needs to be further clarified, we propose NCX-1015 as the first member of a novel class of anti-inflammatory compounds, the nitro-steroids.

Administration, Oral↗