Free radicals: Our enemies or friends ?

Abstract

Free radicals are atoms or groups of atoms containing at least one unpaired electron in their orbitals and can be formed when oxygen interacts with certain molecules. Once formed these highly reactive radicals can start a chain reaction, like dominoes. Their main danger comes from the damage they can do when they react with important cellular components such as DNA, or the cell membrane. Cells may function poorly or die if this occurs. On the other hand they are playing an important role in natural processes involved in cytotoxicity, defense against microorganisms and neurotransmission etc. There are several enzyme systems within the body that neutralize free radicals. The defense system that prevents the body from free radicals’ damage is called as antioxidants. Antioxidants are molecules which can safely interact with free radicals and terminate the chain reaction before vital molecules are damaged. Nowadays most people are under the impression that the field of investigation into antioxidants and free radicals is a brand new phenomenon. The aim of this review is to clarify what is the role of free radicals in our metabolism.