Plasma Malondialdehyde and Exhaled Hydrocarbons: Are They Reliable Indicators of Lipid Peroxidation and Glutathione Peroxidase Activity?

Free radical-mediated oxidation of polyunsaturated fatty acids (PUFA) results in the formation of cytotoxic and bioactive lipid peroxides which are reduced by glutathione peroxidase to harmless lipid alcohols. There are two principle methods that are commonly used for the measurement of lipid peroxides, the malondialdehyde thiobarbituric (MDA-TBA) method and the breath hydrocarbon method. However, interpretation of results obtained using both of these methods is complicated by several factors outlined in this chapter that are frequently not taken into account by investigators in the field. This has led to many conflicting reports in the literature which has fuelled the controversy surrounding the reliability and specificity of these two methods and their scientific value.