Effect of eicosapentaenoic acid (EPA) on tight junction permeability in intestinal monolayer cells

The purpose of this study is to evaluate the effect of C18 and C20 long chain fatty acids on tight junction permeability in a model of intestinal epithelium. Methods: Confluent Caco-2 cells on porous filters with double chamber system were used to measure fluorescein sulfonic acid (FS) permeability and transepithelial electrical resistance (TEER). Lactate dehydrogenase release and ultrastructure were evaluated. Effect of 200 μM eicosapentaenoic acid (EPA, C20:5 n-3), arachidonic acid (AA, C20: 4 n-6), α -linoleic acid (ALA, C18: 3 n-3), linoleic acid (LA, C18: 2 n-6), or oleic acid (OA, C18: 1 n-9) enrichment in the culture medium during 24 hours were compared. The effect of the cyclooxygenase inhibitor, indomethacin, lipoxygenase inhibitors, NDGA or AA861, and antioxidant, BHT, was evaluated as a mechanism to change tight junction permeability. Results: Caco-2 cells formed polarized columner epithelial cells with densely packed microvilli and well developed junctional complexes. Addition of EPA enhanced FS permeability to 3.0±1.6-fold and lowered TEER to 0.59±1.2-fold vs. control with concentration dependency without cell injury (P<0.01–0.05). OA, AA or LA did not change, but ALA enhanced tight junction permeability. Indomethacin and AA861 normalized the changes mediated by EPA.Conclusions: EPA affects tight junction permeability in intestinal monolayer cells specifically and concentration dependently via cyclooxygenase and lipoxygenase products.