Free radicals are byproducts of different physiological processes and have important role in metabolic, signalling and developmental pathways. The environment pollutants, smoking, UV radiations and food can also induce the formation of free radicals or pro-oxidants. The excessive production of free radicals has adverse impact on living organisms and can cause oxidative stress leading to extensive cell damage. Free radical mediated oxidative damage plays important role in pathogenesis of cancer, neurodegenerative, metabolic, reproductive and psychological disorders. Living organisms have...