Free Radicals Induced Oxidative Stress at a Molecular Level: The Current Status, Challenges and Perspectives of Computational Chemistry Based Protocols

Oxidative stress is frequently caused by an excess of free radicals and has been associated with a wide variety of health disorders. Therefore, finding strategies for scavenging free radicals has become an active area of research. This review summarizes, from a physicochemical perspective, relevant strategies to fight oxidative stress via antioxidants, including prevention, deactivation of oxidants, and repair of damaged targets. Different reaction mechanisms involved in the chemical protection exerted by antioxidants are discussed, as well as their relative importance depending on several aspects. Some of them are the polarity of the environment, the pH of aqueous phase, and the chemical nature of the reacting radicals. Data that can currently be obtained from computational, quantum, chemistry, protocols are detailed and their reliability is analyzed. Viable criteria to identify optimal antioxidants using such protocols are provided. Current challenges and future directions in this area of research are discussed. A large set of antioxidants are compared and their trends in activity, based on kinetic data, is provided.