Comparative toxicity of oleic acid and linoleic acid on Raji cells

Objective Parenteral diets are often administered to critically ill patients. To study one of the effects of commercially available parenteral lipid diets, rich in triacylglycerol esters of ω-6 polyunsaturated fatty acids or ω-9 monounsaturated fatty acids, on the immune system of such patients, we evaluated the cytotoxicity of oleic and linoleic acids on Raji cells that had been derived from human B-lymphocytes. Methods Cell death intensity and type were investigated by flow cytometry by quantitation of cell volume, granularity, DNA fragmentation, mitochondrial depolarization, and lipid accumulation. Fluorescence microscopy was used to determine chromatin condensation and type of cell death (acridine orange/ethidium bromide assay). Gene expression of BCL-XL, BCL-XS, C-MYC, and P53 was studied by reverse transcriptase polymerase chain reaction. Results Oleic acid was less toxic than linoleic acid to Raji cells. Both fatty acids promote apoptosis and necrosis of these cells. The mechanism of cell death induced by these fatty acids seemed to involve mitochondrial depolarization, lipid accumulation, and overexpression of C-MYC and P53. Conclusion Oleic acid may offer a less harmful alternative to linoleic acid in parenteral diets with respect to patient B-lymphocyte-mediated immunologic activity.