Eicosanoids and oxidative metabolites of other poly-unsaturated fatty acids represent one of the most potent classes of endogenous cellular mediators. Although about 80% of pharmaceuticals influence the formation of these oxylipins, little is known in regard to alteration by food ingredients. The aim of this project is to investigate the effects of these compounds on endogenous oxylipin levels applying a targeted metabolomics approach. Numerous studies on the impact of nutrition on single eicosanoids have been carried out. Because biological effects arise from a multitude of oxylipins, this approach is incomplete. To solve this problem, we will simultaneously analyze the whole oxylipin pattern of all unsaturated fatty acids using liquid chromatography mass spectrometric methods (LC-MS). This metabolomics approach will provide a more complete description of the biological effects of food ingredients. In a complementary approach, we will test the in vitro effect of food ingredients on the enzymes involved in the pathways of oxylipin formation, particularly their inhibition/activation, as well as their expression levels. For this purpose cell-free enzyme assays for the cyclooxgenase, lipoxygenase, cytochrome P450 and epoxide hydrolase pathways will be established. Pro- and anti-inflammatory effects of the compounds will be investigated in primary cell cultures cells followed by LC-MS read out. With these high-content screening tools, secondary plant metabolites contaminants and food additives will be investigated for modulation of oxylipin formation. The most active compounds will be tested in animal models for effects on regulatory lipids and on physiological end points including atherosclerosis, inflammation and pain. It is proposed that these studies will lead to the discovery of food ingredients that alter regulatory lipids, provide understanding of the system involved, while providing new tools for the pharmacological and toxicological evaluation of xenobiotics.