PUFA and oxidative stress. Differential modulation of the cell response by DHA.

Although an increased dietary intake of long-chain n-3 PUFA is considered an effective preventive strategy, a theoretical concern related to the possible increase of lipid peroxidation induced by a PUFA-rich diet still remains a problem. In this study, the effects of different PUFA (linoleic, α-linolenic, arachidonic, eicosapentaenoic and docosahexaenoic acid) on cytotoxicity, lipid oxidation, and modulation of antioxidant defenses were evaluated in HepG2 cells submitted to an oxidative stress (H2O2). Results clearly evidenced that all supplemented PUFA, but DHA, enhanced cell susceptibility to H2O2. Overall, our results underline that PUFA cannot be considered as a single category but as individual compounds, and research on mechanisms of action and preventive effects should deal with the individual fatty acids, particularly in the case of DHA.