Effect of n-3 fatty acids on the expression of inflammatory genes in THP-1 macrophages

Background: Uncontrolled inflammation participates in the development of inflammatory diseases. Beneficial effects of polyunsaturated fatty acids belonging to the n-3 family such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on inflammation have been reported. The present study investigates the basal effects of EPA, DHA and a mixture EPA + DHA on the expression of 10 genes (AKT1, MAPK, NFKB, TNFA, IL1., MCP1, ALOX5, PTGS2, MGST1and NOS2) related to inflammation in unstimulated cultured THP1 macrophages. Cells were incubated for 24 h with n-3 PUFAs (50 mu M and 10 mu M EPA, DHA, EPA + DHA). Expression levels of inflammatory genes were analyzed by real-time PCR. Results: 50 mu M, 10 mu M EPA and 50 mu M EPA + DHA decreased the expression of genes involved in the NF-kappa B pathway (MAPK, AKT1, and NFKB). Treatment with 50 mu M, 10 mu M EPA, 50 mu M DHA and EPA + DHA decreased expression levels of cytokines genes IL1. and MCP1. TNFA expression was decreased by 50 mu M, 10 mu M of EPA, DHA and with 50 mu M EPA + DHA. Two genes involved in the fatty acid metabolism (PTGS2 and ALOX5) were also modulated by the n-3 FAs. 50 mu M of DHA and EPA + DHA inhibited PTGS2 expression when the two concentrations of EPA, 50 mu M DHA and EPA + DHA inhibited ALOX5 expression. Finally, the effects of n-3 FAs were studied among genes involved in the oxidative stress. 50 mu M of each fatty acid increased MGST1 expression. Both concentration of EPA and 50 mu M DHA decreased NOS2 expression. Conclusion: EPA seems to be more effective than DHA and EPA + DHA in modulating expression levels of selected inflammatory genes. The concentration of 50 mu M was globally more effective than 10 mu M.