title: Characterization of eltenac and novel COX-2 selective thiopheneacetic acid analogues in vitro and in vivo.
abstract: We assessed the effect of novel selective thiopheneacetic acids on cyclooxygenase isoenzymes in vitro and in vivo. Thiopheneacetic acid Eltenac and derivatives were investigated in this study. In human whole blood experiments these derivatives were potent inhibitors of COX-2 (IC(50)=0.02-0.4 microM) with less pronounced effect on COX-1 (IC(50)=0.15-5.6 microM). With COX-1/COX-2 ratios between 7.5- and 16-fold they are in the range of Celecoxib (13-fold). The parent drug Eltenac demonstrated no selectivity for COX-2. In a rat paw edema model, these compounds showed reduction of edema volume in the range of 36-45% at 10 mg/kg (Eltenac 52%, Diclofenac 51%). However, the compounds were superior to Diclofenac and Eltenac with respect to their ulcerogenic and gastrointestinal properties. Introduction of a nitrate-ester moiety to either Eltenac or a derivative did neither improve selectivity or potency in vitro, nor ulcerogenicity in vivo. Molecular modeling of selective thiopheneacetic acid derivatives to the active site of human COX-2 suggested similar binding properties as Lumiracoxib and Diclofenac. In summary, modification of Eltenac generates moderately selective COX-2 drugs in the range of Celecoxib with respect to potency and selectivity. The drugs showed potent anti-inflammatory properties and significant improvement of animal survival in a sub-chronical experimental set up. Thiopheneacetic derivatives are characterized by low pK(a) values, short microsomal half-lives and binding mode to COX-2 similar to Diclofenac and Lumiracoxib. These properties may also have an impact on the transient inhibition of COX-2-dependent prostacyclin, thereby being less associated with vascular complications.
authors.affiliation: Department of Biochemistry, Nycomed GmbH, Byk-Gulden-Strasse 2, 78467 Constance, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Klein
authors.forename: Frank
authors.initials: F
authors.lastname: Dullweber
authors.forename: Christoph
authors.initials: C
authors.lastname: Brehm
authors.forename: Walter
authors.initials: W
authors.lastname: Prinz
authors.forename: Monika
authors.initials: M
authors.lastname: Baudler
authors.forename: Volker
authors.initials: V
authors.lastname: Figala
authors.forename: Michael
authors.initials: M
authors.lastname: Herrmann
mesh_terms: D019342:Acetic Acid / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D000814:Aniline Compounds / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D052246:Cyclooxygenase 2 Inhibitors / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D004487:Edema / Q000188:drug therapy / Q000201:enzymology; D005260:Female; D006801:Humans; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013276:Stomach Ulcer / Q000188:drug therapy / Q000201:enzymology; D013876:Thiophenes / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000814:Aniline Compounds; D052246:Cyclooxygenase 2 Inhibitors; D013876:Thiophenes; C071200:eltenac; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D019342:Acetic Acid