Effect of trans-10, cis-12 Conjugated Linoleic Acid on Production of Prostaglandin E2, Cyclooxygenase-2 and 5-lipoxygenase in Lipopolysaccharide-Stimulated Porcine Peripheral Blood Mononuclear Cells

Abstract

The objective of this study was to examine the effect of trans-10, cis-12 conjugated linoleic acid (t10c12-CLA) on the expression of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) pathway in lipopolysaccharide(LPS)-stimulated porcine peripheral blood mononuclear cells (PBMCs). t10c12-CLA was treated with different concentrations in culture medium of LPS-naive and LPS-stimulated PBMCs. The mRNA expressions of prostaglandin E 2 (PGE 2 )-synthase, COX-2 and 5-LOX were measured using quantitative real-time PCR. In addition, the production levels of PGE 2 and 5-LOX in culture supernatant from PBMCs with or without LPS were assessed by ELISA. In LPS-naive PBMCs, treatment of t10c12-CLA significantly (p 2 synthase and 5-LOX compared to vehicle control. Expression of COX-2 mRNA did not show significant difference compared to vehicle control by t10c12-CLA treatment in LPS-naive PBMCs. However, the addition of LPS in PBMCs markedly (p 2 synthase and 5-LOX, and also significantly (p 2 and 5-LOX relative to LPS-naive PBMCs, respectively. However, the addition of t10c12-CLA significantly (p 2 synthase, and 5-LOX compared to those of PBMCs treated with LPS alone. The production levels of PGE2 and 5-LOX in culture supernatant from LPS-stimulated PBMCs were also significantly (p < 0.05) inhibited by the treatment of t10c12-CLA compared to LPS alone. These results suggested that t10c12-CLA has an anti-inflammatory effect via dual inhibition of COX-2 and 5-LOX with gene expression and production level in LPS-stimulated porcine PBMCs. Therefore, it was thought that t10c12-CLA can attenuate the inflammatory response by down-regulation of eicosanoids production.