Role of Fish Oils in Nutritional Quality: Study of lipid biactive oxygenated mediators

Abstract

Consumption of fish and fish oils has been recently suggested to contribute in the prevention of metabolic disseases such as dyslipidaemia, hyperglycaemia, hypertension or insulin resistance. A novel approach to understand the role of marine ω-3 PUFAs, EPA and DHA, on metabolic health is presented. Eicosanoids and other lipid mediators derived from EPA and DHA, have been pointed like one of the most efficient mechanisms to stop inflammation and oxidative stress in a highly coordinated, active process. The amount of EPA and DHA in fish muscle and fish oils is crucial in the production of these local mediators. However, the simultaneous determination of these fatty acids and their lipid mediators is a challenge due to their instability, low physiological levels and the difficulty of identifying the large number of compounds and isomers formed in vivo with very similar physicochemical properties. The aim of this research was to develop a robust and sensitive targeted analysis platform based on Solid-phase Extraction and LC-ESI-IT-MS/MS for the simultaneous quantification in blood plasma of a large number of eicosanoids/docosanoids and their PUFA precursors. The method here developed overcame issues associated to the thermal stability, the wide range of polarity and physiological concentration of targeted compounds. Moreover, the proposed MS/MS detection mode allowed the discrimination between coeluting isomers minimizing false positive identifications. This lipidomic platform was applied to the production of PUFA metabolites in a metabolic study aimed to test the nutritional effect of different fish oils. Different metabolic effects associated to dispidilemia, oxidative stress and inflammation could be correlated with the different production of lipid mediatorsassociated to each fish oil. Results were stressed in terms of recomendations of the optimised amounts of DHA and EPA in the fish oils