In Vitro Methods for the Evaluation of Oxidative Stress

The study of oxidative stress (OS) phenomena is very relevant for many disciplines including chemistry, biochemistry, physiology and pharmacology. Unfortunately, it is known that no universal test exists for the measurement of OS and different methods should be used for its evaluation in vitro, ex vivo and in vivo. This chapter reviews the recent in vitro methods for the evaluation OS. Firstly, the determination of lipid, protein and DNA oxidation products as biomarkers of exposure to reactive oxygen species (ROS) and how a battery of biomarkers would increase the efficiency and prevent the limitations of a single test which can end up in overestimation as well as underestimations were discussed. In detection of free radicals in biological samples by electron paramagnetic resonance (EPR) part, properties of EPR for the direct detection and identification of free radicals (paramagnetic species) in biological systems were explained. This was followed by the evaluation of fluorescent assays for the detection of ROS and reactive nitrogen species in biological systems. Description of voltammetric methods for low molecular weight antioxidants and significant advantage over the standard spectroscopic tests was discussed. Finally, measurement of OS in bacteria by stating direct and indirect probe-based measurement of the ROS and measurement of the oxidative damage to biomolecules as well as assessment of the antioxidant enzymes activities. This chapter will give an overview of the processes of in vitro methods for the evaluation of OS and touch briefly the most favored methods and techniques.

Keywords: Bacteria, EPR, Fluorescent assays, Oxidation products, Oxidative stress, Reactive species, Voltammetry.