Total Oxyradical Scavenging Capacity as an Index of Susceptibility to Oxidative Stress in Marine Organisms

Formation of reactive oxygen species (ROS) is a natural event for aerobic organisms, but it can be exacerbated by both biological and environmental factors. Cellular oxidative damage is well documented in aquatic organisms, and variations of antioxidants can be sensitive in revealing a pro-oxidant condition. Nonetheless, such effects are difficult to predict according to chemicals, kind of exposure, and species sensitivity. Measuring the overall efficiency of cellular antioxidants toward oxyradicals provides a more integrated assessment of susceptibility of a tissue to oxidative stress. Among the methods for analyzing total antioxidant capacity, the total oxyradical scavenging capacity (TOSC) assay offers the possibility to discriminate different oxyradicals, indicating the roles of these species or their metabolic pathways of formation, in the onset of oxidative disease. The TOSC assay has been widely used on marine organisms under natural and disturbed condition suggesting temporal and causal relationships among increased ROS formation, onset of antioxidant responses, and potential occurrence of oxidative damages and toxicity to cellular targets.