Piero Del Soldato

Nitric Oxide-Donating Nonsteroidal Anti-Inflammatory Drugs Inhibit the Growth of Various Cultured Human Cancer Cells: Evidence of a Tissue Type-Independent Effect

The novel nitric oxide (NO)-donating nonsteroidal anti-inflammatory drugs (NO-NSAIDs), which are safer than their NSAID counterparts, inhibit the growth of colon cancer cells with far greater potency than traditional NSAIDs. We examined whether NO-NSAIDs inhibit the growth of cancer cells arising from other human tissues. Human pancreatic, colon, prostate, lung, and tongue cancer cell lines were treated with NO-aspirin, -sulindac, -ibuprofen, and -indomethacin or their traditional counterparts. We determined IC50 values, cell proliferation, apoptosis, cell cycle, cyclooxygenase (COX) protein levels, and morphological changes (light and electron microscopy). All NO-NSAIDs inhibited the growth of all cancer cell lines studied. The potency of NO-NSAIDs was 11- to 6000-fold greater than that of their counterparts (except for the effect of sulindac on lung cancer cells). NO-aspirin was consistently the most potent NO-NSAID in all cell lines tested (except for the lung cancer cell line), sometimes in excess of 100-fold over the other three NO-NSAIDs. NO-NSAIDs inhibited cell proliferation, induced apoptosis, and altered cell cycle phase distribution (G2/M to G0/G1 block). All altered cellular morphology, whereas NO-aspirin induced nuclear disintegration (“atypical” cells) established by electron microscopy. NO-aspirin showed similar effects on two pancreatic cancer cell lines, BxPC-3 (expresses COX) and MIA PaCa-2 (no COX expression), suggesting a COX-independent effect. NO-NSAIDs showed a tissue-type-independent effect. Their pleiotropic effects involve cell renewal, cell death, and cell cycle phase transitions. These results raise the possibility that NO-NSAIDs possess chemopreventive and/or chemotherapeutic activity against a wide variety of human cancers.

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.

Comparison of the gastric cytoprotective properties of atropine, ranitidine and PGE2 in rats.

In view of the controversy as to whether antisecretory agents such as H2 antagonists and antimuscarinics might be cytoprotective like the PGs, the oral activity of atropine, ranitidine and PGE2 against absolute ethanol-induced lesions was evaluated in rats. The results showed that atropine and PGE2, but not ranitidine, were effective in preventing absolute ethanol-induced gastric damage. The effects were related to the doses of the ulcerogenic agent and of the cytoprotective compound. The anti-ulcer activity of atropine is considered to be an expression of cytoprotection, since the pathogenesis of ethanol-induced gastric damage was independent of gastric pH and atropine, like PGE2, does not affect basal acid secretion at a fully cytoprotective dose. Some studies were undertaken to elucidate the mechanism of gastric cytoprotection by atropine. The possibility that the anti-muscarinic agent might work as a mild irritant was ruled out since, like PGE2, the agent was still effective in PG-deficient rats. The evidence that neostigmine markedly aggravated gastric damage caused by low doses of absolute ethanol and that atropine completely prevented this damage postulates mechanisms involving specific muscarinic receptor interactions.

Nitroaspirin plus clopidogrel versus aspirin plus clopidogrel against platelet thromboembolism and intimal thickening in mice

Clopidogrel plus aspirin is the treatment of choice for patients undergoing percutaneous, coronary interventions with stenting, but it does not prevent restenosis. NCX-4016, a nitric oxide-releasing aspirin (nitroaspirin), exerts a wider range of antiplatelet actions compared to aspirin, superior antithrombotic activity and reduces restenosis after arterial injury in animals. The aim of the present study was to compare the combination of nitroaspirin plus clopidogrel with aspirin plus clopidogrel in a model of platelet pulmonary thromboembolism, bleeding and intimal thickening in mice. Drugs were administered orally for 5 days; the antithrombotic effects were evaluated against collagen plus epinephrine-induced pulmonary thromboembolism, the haemorrhagic effects by tail transection bleeding time and the effects on neointima proliferation by histomorphology of photochemically injured femoral arteries. Lung platelet emboli were reduced significantly and more effectively by nitroaspirin plus clopidogrel (-56%, p<0.05 vs control) than by aspirin plus clopidogrel (-26%, p<0.05 vs control). Ex vivo platelet aggregation was inhibited maximally by nitroaspirin plus clopidogrel. Aspirin plus clopidogrel strikingly prolonged the bleeding time while nitroaspirin plus clopidogrel induced a lesser prolongation. Nitroaspirin plus clopidogrel significantly reduced intimal thickening of the femoral artery while aspirin plus clopidogrel was ineffective. Nitroaspirin plus clopidogrel is more effective and less prohaemorrhagic than aspirin plus clopidogrel in mice; provided these data are confirmed in other animal models, nitroaspirin plus clopidogrel may represent a new regimen to be tested in patients undergoing coronary revascularization procedures.

Effects of flurbiprofen and flurbinitroxybutylester on prostaglandin endoperoxide synthases.

The aim of our study was to evaluate the selectivity of flurbiprofen and flurbinitroxybutylester for inhibition of the cyclooxygenase activity of prostaglandin endoperoxide synthase-2 vs. prostaglandin endoperoxide synthase-1 in human blood monocytes and platelets, respectively. In whole blood, flurbiprofen was approximately 10-fold more potent that flurbinitroxybutylester to inhibit the cyclooxygenase activity of platelet prostaglandin endoperoxide synthase-1 (IC50 microM: 0.90 +/- 0.27 vs. 10.70 +/- 5, mean +/- S.D., P < 0.05). In contrast, the 2 compounds were equipotent to inhibit prostaglandin endoperoxide synthase-2 cyclooxygenase activity in whole blood (IC50 microM: 0.90 +/- 0.25 vs. 0.80 +/- 0.35) or isolated monocytes (IC50 microM: 0.03 +/- 0.02). Neither flurbiprofen nor flubinitroxybutylester (0.28-112 microM) affected prostaglandin endoperoxide synthase isozyme expression by lypopolysaccharide-stimulated monocytes. In whole blood, flurbinitroxybutylester was slowly converted to flubiprofen and this in turn could influence the extent of inhibition of the cyclooxygenase activity of prostaglandin endoperoxide synthase-1. In conclusion, the addition of a nitroxybutyl moiety to flurbiprofen seems to reduce its capacity to inhibit the cyclooxygenase activity of prostaglandin endoperoxide synthase-1. Whether this effect will result in a reduced risk of gastrointestinal toxicity remains to be studied in man.

The effects and metabolic fate of nitroflurbiprofen in healthy volunteers

Nitric oxide–donating nonsteroidal anti‐inflammatory drugs (NO‐NSAIDs) are a new class of cyclooxygenase (COX) inhibitors. To investigate whether these drugs actually release nitric oxide (NO), we labeled the nitroxy group of nitroflurbiprofen with nitrogen 15 to determine the metabolic fate of this compound in humans.

Nitric Oxide-Releasing Non Steroidal Anti-Inflammatory Drugs: A New Generation of Anti-Tumoral Molecules

Colorectal cancer is the second most common cause of cancer-related mortality in the west. The high incidence and mortality make effective prevention an important public-health and economic issue. The regular intake of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has been associated with decreased incidence of certain types of cancer particularly those with an inflammatory component, and then are among the few agents known to be chemopreventive. Nitric oxide-releasing non-steroidal anti-inflammatory drugs (NO-NSAIDs) are new chemical entities obtained by adding a nitric oxide-releasing moiety to classical molecules. This new class of molecules has been demonstrated to be much more safe than NSAIDs due to their ability to reduce gastric toxicity. They could therefore represent an alternative to classical NSAIDs treatment. In this review, we sumarise the recent findings in the mechanisms and pathways involved in the antitumoral effects of both NSAIDs and NO-NSAIDs as well as the clinical trials performed with these compounds.

Nitric oxide-donating aspirins spare the gastrointestinal (GI) system and improve the treatment of inflammation-related GI and cardiovascular pathologies

For decades, aspirin has represented the elective treatment for inflammatory-based pathologies, due to its antipyretic and anti-inflammatory activities [1].