Regulation of reactive oxygen species (ROS) production by C₁₈ fatty acids in Jurkat and Raji cells

In the present study, the effects of C₁₈ fatty acids with different numbers of double bonds, SA (stearic acid; C_18:0), OA (oleic acid; C_18:1), LA (linoleic acid; C_18:2) and γ-LNA (γ-linolenic acid; C_18:3), on ROS (reactive oxygen species) production by Jurkat (a human T-lymphocyte-derived cell line) and Raji (a human B-lymphocyte-derived cell line) cells were investigated. ROS production was determined by NBT (Nitro Blue Tetrazolium) reduction (intracellular and extracellular ROS production) and by dihydroethidium oxidation using flow cytometry (intracellular ROS production). The effectiveness on ROS production was γ-LNA<SA<OA<LA in Jurkat cells and SA<γ-LNA<OA<LA in Raji cells. LA (found in corn, soya bean and sunflower oils) was more potent than OA (found in olive oil) in stimulating ROS production in both Raji and Jurkat cells. The lower ROS production by OA compared with LA may be one of the benefits of olive oil consumption. As SA and γ-LNA acids had little or no effect, further studies on the site of ROS production in these cells were carried out with OA and LA only. Activation of NADPH oxidase via PKC (protein kinase C) was found to be the major mechanism of ROS production induced by OA and LA in Jurkat and Raji cells.