antioxidant activity

View with images and charts Antioxidant Activity Introduction The largest parts of the diseases are mainly linked to oxidative stress due to free radicals (Gutteridgde, 1995). Antioxidants can interact with the oxidation process by reacting with free radicals, chelation, catalyzing metals, and also by acting as oxygen scavengers (Buyukokuroglu et al., 2001). Literature reviews have shown that there was much effort to invent medicine to overcoming the death. But until recently the actual cause of aging was not known. There is considerable recent evidence that free radical induce oxidative damage to biomolecules. This damage causes aging, diabetes, cancer, malaria, neurodegenerative diseases and other pathological events in living organisms (Halliwell et al. 1992). Antioxidants which scavenge free radicals are known to posses an important role in preventing these free radical induced-diseases. There is an increasing interest in the antioxidant effects of compounds derived from plants, which could be relevant in relations to their nutritional incidence and their role in health and diseases (Steinmetz et al., 1996; Aruoma, 1998; Bandoniene et al., 2000; Pieroni et al., 2002; Couladis et al., 2003). A number of reports on the isolation and testing of plant derived antioxidants have been described during the past decade. Natural antioxidants constitute a broad range of substances including phenolic or nitrogen containing compounds and carotenoids (Shahidi et al., 1992; Velioglu et al., 1998; Pietta et al., 1998). The medicinal properties of plants have been investigated throughout the world, due to their potent antioxidant activities, minimum or no side effects and economic viability (Auudy et al., 2003). Lipid peroxidation is one of the main reasons for deterioration of food products during processing and storage. Synthetic antioxidant such as tert-butyl-1-hydroxitoluene (TBHT), tert-butylhydroquinone (TBHQ), butylated hydroxianisole (BHA) and propyl gallate (PG) are widely used as food additives to increase shelf life, especially lipid and lipid containing products by retarding the process of lipid peroxidation. However, TBHT and BHA are known to have not only toxic and carcinogenic effects on humans (Ito et al. ,1986; Wichi, 1988), but also abnormal effects on enzyme systems (Inatani et al. 1983). Thus, the interest in natural antioxidant, especially of plant origin, has greatly increased in recent years (Jayaprakasha et al., 2000). Plant polyphenols have been studied largely because of the possibility that they might underlie the protective effects afforded by fruit and vegetable intake against cancer and others chronic diseases (Elena et al., 2006). Antioxidants: The free radical scavengers Oxygen is the highest necessary substance for human life. But it is a Jeckyl and Hyde (both pleasant and unpleasant) element. We need it for critical body functions, such as respiration and immune response, but the element’s dark side is a reactive chemical nature that can damage body cells. The perpetrators of this “oxidative damage” are various oxygencontaining molecules, most of which are different types of free radicals—unstable, highly energized molecules that contain an unpaired electron. Since stable chemical bonds require electron pairs, free radicals generated in the body steal electrons from nearby molecules, damaging vital cell components and body tissues. Oxidative damage in the body is akin to the browning of freshly cut apples, fats going rancid,

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