ABSTRACT
Antioxidant activity includes several mechanisms of action, such as inhibition of oxidative enzymes responsible for the formation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), induction of the expression of defense enzymes (superoxide dismutase, catalase), and metal-chelating action. Scavenging activity or reducing capacity acts as the second line of defense by removing or reducing reactive species before oxidative damage of biomolecules such as proteins, phospholipids, and DNA occurs (Valko et al., 2007; Lopez-Alarcon and Denicola, 2013). In fact, these two antioxidant mechanisms are one of the main active factors in the body’s defense system (Niki, 2010). The available methodologies for assessing these two types of antioxidant action will be discussed in this chapter, highlighting their adaptation to microplate format and to automatic ow-based systems. A critical contribution of the different analytical approaches developed until the present moment for fast screening of antioxidant activity will also be discussed.
