COX-1 and COX-2 inhibition in horse blood by phenylbutazone, flunixin, carprofen and meloxicam: an in vitro analysis.
We report on the inhibitory activity of the NSAIDs meloxicam, carprofen, phenylbutazone and flunixin, on blood cyclooxygenases in the horse using in vitro enzyme-linked assays. As expected, comparison of IC50 indicated that meloxicam and carprofen are more selective inhibitors of COX-2 than phenylbutazone and flunixin; meloxicam was the most advantageous for horses of four NSAIDs examined. However at IC80, phenylbutazone (+134.4%) and flunixin (+29.7%) had greater COX-2 selectivity than at IC50, and meloxicam (-41.2%) and carprofen (-12.9%) had lower COX-2 selectivity than at IC50. We therefore propose that the selectivity of NSAIDs should be assessed at the 80% as well as 50% inhibition level.
Beretta
C
C
Department of Veterinary Clinical Sciences, Faculty of Veterinary Medicine, Via Celoria 10, 20133 Milan, Italy. carlo.beretta@unimi.it
Garavaglia
G
G
Cavalli
M
M
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002227:Carbazoles / Q000494:pharmacology; D003002:Clonixin / Q000031:analogs & derivatives / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D015232:Dinoprostone / Q000097:blood; D005260:Female; D006736:Horses; D066298:In Vitro Techniques; D008297:Male; D000077239:Meloxicam; D010653:Phenylbutazone / Q000494:pharmacology; D013843:Thiazines / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013929:Thromboxane B2 / Q000097:blood
D000894:Anti-Inflammatory Agents, Non-Steroidal; D002227:Carbazoles; D016861:Cyclooxygenase Inhibitors; D013843:Thiazines; D013844:Thiazoles; C014557:flunixin; D013929:Thromboxane B2; C007005:carprofen; D010653:Phenylbutazone; D015232:Dinoprostone; D003002:Clonixin; D000077239:Meloxicam