Medicinal plants are the important natural resources to fight serious diseases, especially in developing countries. Antioxidants play an important role in human health, because they have been recognized to be capable of lowering the incidence of various diseases such as cancer and angiocardiopathy. The antioxidant is a substance that, when present at low concentrations compared to those of an oxidizable substrate, significantly delays or prevents oxidation of that substrate. Different parts of plants such as roots, seeds, bark, leaves and flowers could be used for remedial purposes. Natural antioxidant proteins are mainly found in plants and animals, which interact to eliminate excessive free radicals and protect cells and DNA from damage, prevent and treat some diseases, and it is so important for the development of new drugs and research related diseases.