title: Inhibition of inducible nitric oxide synthase expression by novel nonsteroidal anti-inflammatory derivatives with gastrointestinal-sparing properties.
abstract: 1. The effects of novel nitric oxide-releasing nonsteroidal anti-inflammatory compounds (NO-NSAIDs) on induction of nitric oxide (NO) synthase by bacterial lipopolysaccharide (LPS) were examined in a murine cultured macrophage cell line, J774. 2. LPS-induced nitrite production was markedly attenuated by the nitroxybutylester derivatives of flurbiprofen (FNBE), aspirin, ketoprofen, naproxen, diclofenac and ketorolac, with each compound reducing accumulated nitrite levels by > 40% at the maximum concentrations (100 micrograms ml-1) used. 3. Further examination revealed that nitrite production was inhibited in a concentration-dependent (1-100 micrograms ml-1) manner by FNBE which at 100 micrograms ml-1 decreased LPS-stimulated levels by 63.3 +/- 8.6% (n = 7). The parent compound flurbiprofen was relatively ineffective over the same concentration-range, inhibiting nitrite accumulation by 24 +/- 0.9% (n = 3) at the maximum concentration used (100 micrograms ml-1). 4. FNBE reduced LPS-induced nitrite production when added to cells up to 4 h after LPS. Thereafter, FNBE caused very little or no reduction in nitrite levels. Furthermore NO-NSAIDs (100 micrograms ml-1) did not inhibit the metabolism of L-[3H]-arginine to citrulline by NO synthase isolated from LPS-activated macrophages. 5. Western blot analysis demonstrated that NO synthase expression was markedly attenuated following co-incubation of J774 cell with LPS (1 microgram ml-1; 24 h) and FNBE (100 micrograms ml-1; 24 h). Thus taken together, these findings indicate that NO-NSAIDs inhibit induction of NO synthase without directly affecting enzyme activity. 6. In conclusion our results indicate that NO-NSAIDs can inhibit the inducible L-arginine-NO pathway, and are capable of suppressing NO synthesis by inhibiting expression of NO synthase. The clinical implications of these findings remain to be established.
authors.affiliation: Vascular Biology Research Centre, King's College, London.
authors.forename: G
authors.initials: G
authors.lastname: Cirino
authors.forename: C P
authors.initials: CP
authors.lastname: Wheeler-Jones
authors.forename: J L
authors.initials: JL
authors.lastname: Wallace
authors.forename: P
authors.initials: P
authors.lastname: Del Soldato
authors.forename: A R
authors.initials: AR
authors.lastname: Baydoun
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology; D015153:Blotting, Western; D002460:Cell Line; D004790:Enzyme Induction / Q000187:drug effects; D004926:Escherichia coli; D005480:Flurbiprofen / Q000031:analogs & derivatives / Q000494:pharmacology; D007660:Ketoprofen / Q000494:pharmacology; D008070:Lipopolysaccharides; D008264:Macrophages / Q000201:enzymology; D051379:Mice; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D009573:Nitrites / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D008070:Lipopolysaccharides; D009573:Nitrites; D009569:Nitric Oxide; D005480:Flurbiprofen; D007660:Ketoprofen; D019001:Nitric Oxide Synthase; D001241:Aspirin