ABSTRACT
Oxidative stress plays an important role in the pathogenesis of various diseases such as atherosclerosis, alcoholic liver cirrhosis and cancer etc. Oxidative stress is initiated by reactive oxygen species (ROS), such as superoxide anion (O-2), perhydroxy radical (HOO-) and hydroxyl radical (HO·). These radicals are formed by a one electron reduction process of molecular oxygen (O2). ROS can easily initiate the lipid peroxidation of the membrane lipids, causing damage of the cell membrane of phospholipids, lipoprotein by propagating a chain reaction cycle [1,2]. Thus, antioxidants defense systems have coevolved with aerobic metabolism to
counteract oxidative damage from ROS. Most living species have efficient defense systems to prevent themselves against oxidative stress induced by ROS [3]. Recent investigations have shown that the antioxidant properties of plants could be correlated with oxidative stress defense and different human diseases and aging process etc [4]. In this respect flavonoids and other polyphenolic compounds have received the greatest attention.
