Antioxidants as Functional Foods in Metabolic Syndrome

Free Radicals And Oxidative Stress

A chemical reaction in which the electrons get transferred from a substance to an oxidizing agent is known as oxidation, which in turn produces free radicals (any independently existing chemical species having one or more unpaired electrons), which produced in excess, ultimately results in oxidative stress. Oxidation reactions are an essential part of normal metabolism as oxygen is the ultimate electron acceptor in the electron flow system that produces adenosine triphosphate – ATP, source of energy in body. Problems may arise when electron flow and energy production become uncoupled followed by the increased production of oxygen free radicals like ROS. It is a known fact that molecular oxygen can be reduced to water. The intermediate steps involved in this reduction of molecular oxygen are the formation of free radicals such as superoxide anions, hydrogen peroxide and hydroxyl radicals. Once these radicals are formed, they can react with each other or with another molecule depending on its concentration. The increase in such pro-oxidants is directly involved in pathogenesis or as a result of an aerobic metabolic process. The body continually battles to maintain levels of pro-oxidants and antioxidants to reduce the occurrence of chronic diseases. Nevertheless, reduced concentration of endogenous antioxidants to neutralise the released free radicals results in severe oxidative stress consequently leading to cell damage and death.