Antioxidants and their role in biological functions: An overview

Antioxidants are compounds which even at relatively small concentrations act as inhibitors of the process of oxidation and they are quite large in number and diversity. The enzymatic versatile antioxidants like superoxidedismutase, glutathione peroxidase, catalase etc., the non-enzymatic antioxidants like vitamin E, vitamin C, Ginkgo Biloba extract, spirulina, red wine, spices like garlic, pepper etc. and the synthetic compounds like melatonin, dihydroepiandrosterone (DHEA) and their role in various physiological functions are described. The involvement of free radical attacks in aging and in some pathological functions leading to an accelerated aging or disorders such as Down's syndrome, Alzheimer's disease, Parkison's disease, hepatitic damage, diabetes, hypertension etc. have been extensively discussed. However, owing to the vast gap between the complete knowledge on antioxidant defense systems and many of the undesired old age diseases and oxidative damages in practice caused to cellular proteins and enzymes in vivo, neither the old age diseases have been satisfactorily got rid off nor the cellular damages are effectively controlled. To bridge this gap, further extensive research work therefore, is necessarily be carried out on antioxidants and their clear role in inhibiting the oxidative damages caused in various pharmacologically active substances.