Amit Kumar, A K Bhagi
ABSTRACT
Physiological processes in a healthy organism are mediated via reactive species i.e. free radicals and their reactive metabolites. These reactive species also forms the basis of prevention mechanism of an organism against invading pathogens. A certain concentration of these reactive species is very essential for sustaining normal metabolism functions of living organisms. Under oxidative stress conditions these reactive species exert harmful effects on important biomolecules. To deal with oxidative stress and its related disorders antioxidant mechanisms are in place as protection against these reactive species. Both endogenous and exogenous or dietary antioxidants are very important. The article presents detailed discussion of the various types of reactive species, present in the living systems as defence against invading pathogens, their origin, positive functions and effects in the health condition oxidative stress. Endogenous as well as exogenous antioxidant prevention mechanism is also discussed.
Keywords : Antioxidants, Free radicals, Oxidative stress, Flavonoids, Enzymes, Carotenoids, Tocopherols etc.