Oxygen free radicals (OFR) also known as reactive oxygen species (ROS) are formed as a consequence of normal oxidative metabolism. Their generation goes up substantially under chronic inflammatory conditions and ischemia. These free radicals have multifarious effects that include oxidative damage to DNA leading to various human degenerative diseases. Out of these species, hydroxyl radical is highly reactive and can virtually react with any cell macromolecule, the DNA being the most susceptible. Oxidative damage to DNA includes strand breaks, sister chromatid exchange, and subsequent generation of clastogenetic factors, alterations in basic structure and conformational changes (1,2).
