Evidence suggests that dysregulation of this fine balance leads to the chronic inflammatory state that is characteristic of IBD ( Reference Caradonna, Amati, Magrone, Pellagrino, Jirillo and Caccavo 4 ). In these circumstances cytokines play an essential role in gut homeostasis ( Reference Monteleone, Peluso, Fina, Caruso, Andrei, Tosti and Pallone 3 ). In normal intestinal epithelial cells, equilibrium between tolerance to microflora and immune response to pathogenic bacteria is constantly maintained.
As many as one in 100 individuals in Europe suffer one or more often prolonged episodes of IBD in their lifetime ( Reference Lakatos 2 ). However, recent studies have determined that factors such as genetic disposition, stress and diet are involved in disease pathogenesis ( Reference Innis, Pinsk and Jacobson 1 ). Inflammatory bowel disease (IBD) is a condition with uncertain aetiology. Thus the present study established that TVA treatment can alter SCD desaturation indices and induce compositional changes in the fatty acid profile of the Caco-2 cell model of the human intestinal epithelium but this is not associated with functional effects on markers of the inflammatory response. However, CLA, but not TVA, significantly modulated transcription of TNF-α, IL-12, IL-6 and production of IL-12 by these cells. Treatment with both TVA and c9, t11-CLA resulted in alteration of cellular fatty acid profile and SCD activity in the Caco-2 cell line. The present study demonstrated that TVA treatment led to significant bioconversion into c9, t11-CLA in Caco-2 cells. The aim of the present study was to determine if TVA is bioconverted to c9, t11-CLA in intestinal epithelial cells and to ascertain whether TVA has effects similar to c9, t11-CLA on markers of inflammation relevant to inflammatory bowel disease.
c9, t11-CLA has been associated with anti-inflammatory effects and also affects lipid metabolism. It is converted to the cis-9, trans-11 isomer of conjugated linoleic acid (c9, t11-CLA) by the action of stearoyl-CoA desaturase (SCD) in tissue. Trans-vaccenic acid (TVA) is a natural trans fatty acid found in ruminant food produce.