12NATURAL ANTI-OXIDANTS AND IN-VITRO METHODS FOR ANTI-OXIDANT ACTIVITYOxidative stress might be an important part of many human diseases; the use of antioxidants in pharmacology is intensively studied, particularly as treatments for stroke, dementia and neurodegenerative diseases. Antioxidants are widely used as ingredients in dietary supplements in the hope of maintaining health and preventing diseases such as cancer and coronary heart disease. In addition antioxidants are added to a variety of foods to prevent the lipid peroxidation. These compounds have many industrial uses, such as preservatives in food and cosmetics and preventing the degradation of rubber and gasoline. This article focused on natural anti-oxidants and evaluating in-vitro methods for anti-oxidant activity. zechariahjebakumar@gmail.comReview212012Anti-oxidant Activity,In-Vitro Methods,Natural Anti-oxidantsA. Zechariah Jebakumar,, Hassan S. Nondo,Siju K. George, G.Manoj Dept. of Research and Scientific studies, Prince Sultan Military college of Health Sciences, Dhahran-31932, Kingdom of Saudi Arabia., Dept. of Research and Scientific studies, Prince Sultan Military college of Health Sciences, Dhahran-31932, Kingdom of Saudi Arabia., Dept. of Research and Scientific studies, Prince Sultan Military college of Health Sciences, Dhahran-31932, Kingdom of Saudi Arabia.,Dept of Pharmacology, C.L. Baid Metha College of Pharmacy, Thoraipakkam, Chennai - 600096, India.