Estimation of peroxidative damage. A critical review.

Numerous methods have been developed to measure lipid peroxidation products and lipid peroxidation damage in tissues, cells and body fluids. The choice of which method is most appropriate depends, amongst others, on the specific interest of the investigator. In the routine clinical and laboratory praxis, the determination of thiobarbituric acid reactive substances (TBARS) under strictly standardized conditions is in most cases the first choice. The specificity of the colorimetric or fluorimetric assay can be significantly improved if combined with HPLC. If levels of TBARS are increased, other more sophisticated assays should be performed for verification. Assays are available for: Phospholipid- and cholesterylester hydroperoxides, aldehydic lipid peroxidation products including 4-hydroxynonenal, fluorescent protein adducts (e.g. lipofuscin), conjugated dienes and antioxidants. The measurement of pentane and ethane in the exhaled air by gas chromatography is the only available non-invasive method. Several laboratories currently develop immunological assays (ELISA, RIA) for determining proteins modified by lipid peroxidation products (e.g. malonaldehyde, 4-hydroxynonenal) or autoantibodies against oxidatively modified proteins. It can be expected that such assays will soon gain diagnostic importance.