Simple Assay for the Level of Total Lipid Peroxides in Serum or Plasma

As is well-recognized, lipid peroxidation is initiated by the abstraction of a hydrogen atom from a polyunsaturated fatty acid, and proceeds via free-radical species to form the primary stable product, lipid hydroperoxide, and then the secondary stable product, lipid aldehyde, as depicted in Fig. 1. To check lipid peroxidation in the body, investigate free radical injury, or aid in the diagnosis of lipid peroxide-mediated diseases, one of the most routine test samples is serum or plasma. In serum and plasma, however, free-radical species involved in the process shown in Fig. 1 all disappear because of their short lifetime, and only stable substances remain. Even such stable substances are liable to decompose to some extent, and, therefore, prolonged treatment or organic solvent-extraction should be avoided. Accordingly, the principle of the procedure presented here is to react these lipid peroxides with a suitable reagent after eliminating other reactive or disturbing substances.