Biomarkers of inflammation in cattle determining the effectiveness of anti-inflammatory drugs

Abstract

The impact of nonsteroidal anti-inflammatory drugs (NSAID) on prostaglandin E(2) (PGE(2)) production and cyclooxygenase 2 (COX-2) mRNA expression in bovine whole blood (WB) cultures stimulated by lipopolysaccharide (LPS) was determined, using the blood from six Holstein dairy cattle in various stages of lactation. Peak production of PGE(2) occurred 24 h after LPS stimulation but did not result in detectable concentrations of thromboxane B(2) (TXB(2)). The NSAID indomethacin, aspirin, flunixin meglumine, and 4-[5-phenyl-3-(trifluoromethyl)-1H-pyrazol-1-yl] benzene sulfonamide (PTPBS; celecoxib analogue), along with dexamethasone, were all equally effective in reducing the concentration of PGE(2) in the bovine WB culture supernatants. Bradykinin exhibited peak supernatant concentrations 1 h after LPS stimulation. Dexamethasone and the NSAID used in this study were equally effective at inhibiting bradykinin production. Peak induction of COX-2 mRNA occurred 3 h post-LPS stimulation. However, neither dexamethasone nor any of the NSAID used in this study altered COX-2 mRNA concentrations. In contrast, aspirin, flunixin meglumine, and PTPBS reduced tumor necrosis factor-alpha (TNFalpha) mRNA concentration. These results demonstrate that bovine blood cells respond to NSAID therapy like other mammalian cells with respect to inhibition of PGE(2) production and suppression of TNF mRNA induction, but do not inhibit induction of COX-2 mRNA.