Antioxidant

Definition

An antioxidant is a substance that has the ability to prevent oxidation. An antioxidant can act to inhibit an oxidant or reactions promoted by reactive oxygen species. Reactive oxygen species (ROS) comprise free radicals (pro-oxidant molecules such as superoxide) and non-radical species (such as hydrogen peroxide) and are produced in normal bodily processes such as metabolism or respiration. ROS are aptly named as they are indeed very reactive, and will oxidize proteins, lipids, or DNA that they come into contact with, causing adducts or altering the function of these bodily molecules. Antioxidants serve to prevent damage or dysfunction by balancing ROS production and effectively neutralizing them. Examples of antioxidants in the body may be endogenous (produced by the body) or exogenous (taken in via the diet). Endogenous antioxidants, including the enzymes superoxide dismutase and catalase, may be upregulated, or increased, in response to ROS release. Examples of exogenous...