Impact of Natural Antioxidants on Biological Systems
Malka Samra Malik, Muhammad Azam, Muhammad Asim Raza Basra
Free radicals are the unstable electron-deficient species that reacts with different molecules to gain stability and to eliminate their unpaired condition. Antioxidant molecules neutralizes the free radicals by donating their electrons and inhibits the unwanted oxidative reactions in biological system. The imbalance between antioxidants and free radicals generated oxidative stress which leads to severe impairment of the biological systems. The purpose of the present review is to highlight the beneficial role of naturally occurring antioxidant systems in minimizing the damage and maintaining the homeostasis in the biological system. Enzymatic and non-enzymatic antioxidants are the major classes of natural antioxidants which executes diverse functions in the biological system to provide defense against the destructive accumulating effects of ROS/RNS. Superoxide dismutase (SOD) are responsible for providing first line of defense to the
biological system, by converting the superoxide anion radical (O oˉ) into hydrogen 2 peroxide (H O ) which eventually converted into water and oxygen. Non-enzymatic 2 2 antioxidants either endogenous or exogenous provides numerous crucial mechanisms to quench the ROS/RNS in the biological system. Endogenous antioxidants inhibits lipid peroxidation in the cellular membranes while the exogenous antioxidants acts as chain breakers and terminates the oxidative chain reaction. It is significant to sustain the level of exogenous antioxidants in the body through diet so that the normal biological
processes can be maintained at optimal levels.