Non enzymatic metabolites of polyunsaturated fatty acids: friend or foe

Under condition of oxidative stress, free radical mediated peroxidation of polyunsaturated fatty acids generates in vivo, cyclic metabolites like the isoprostanes, neuroprostanes, dihomo-isoprostanes, isofuranes among a large number of key products which participate in many pathophysiological processes. These metabolites display a wide range of biological actions, and some of them are now the most reliable indicators of oxidative stress in humans. In this review, we will discuss several key points of our understanding of those cyclic polyunsaturated fatty acids derivatives, going from multi-step syntheses, analytical chemistry and biological activities.