Abstract
Free radicals (FR) are chemical species of significant importance to biological systems. FRs are generated by endo- as well as exogenous factors. Biological systems are equipped with appropriate metabolic pathways to remove cellular FR as well as repair the damages caused by them. Their cellular/physiological load profoundly influences the metabolism, physiology and overall well being of biological systems. Therefore, they are implicated in cellular degenerative processes and in patho-physiology, including carcinogenesis and ageing. The review shall attempt to give a generalized overview of FR chemistry, especially to the biologically important oxygen free radicals (OFR) and reactive oxygen species (ROS). The review shall also discus the OFR/ROS biology to get an overview of the induced damage at molecular, cellular and organismal levels in order to give a perspective of their influences on the genomic integrity, cellular microenvironment and physiology with special reference to human health.
Keywords: Free radicals, Reactive oxygen species, DNA, Cellular and molecular damage, Diseases, hemolytic cleavage