Superoxide Dismutase (SOD) is an antioxidant enzyme that destroys a reactive form of OXYGEN called superoxide. Superoxide (02) is a type of FREE RADICAL. As such it is very reactive chemically. Stimulated neutrophils and macrophages, two types of immune cells responsible for eliminating foreign materials, release superoxide to kill bacteria. A mechanism that enhances the destruction of virus-infected cells also operates through superoxide. Superoxide can also occur in MITOCHONDRIA, the powerhouses of cells. They consume most of the oxygen used by cells in order to burn fuels for energy; they can produce superoxide as a by-product. Superoxide can react with cellular metal ions to produce hydroxyl radicals, an extremely reactive free radical that can attack DNA and cause mutations. Oxidative damage is believed to underlie degenerative conditions including cardiovascular disease, premature aging, cancer and even senility.

Three variants of superoxide dismutase require COPPER, and ZINC or MANGANESE. Consequently these trace mineral nutrients are classified as ANTIOXIDANTS. Copper and zinc SOD are the major forms in the body and they are essential in protecting cells against damage due to inflammation. Injected SOD has been used to treat ARTHRITIS, CROHN’S DISEASE, LUPUS ERYTHEMATOSUS and other conditions related to an imbalanced immune system and severe inflammation.

Superoxide dismutase is sold as a supplement in health food stores. The idea behind these pills is to bolster the body’s enzymes. Generally the levels of superoxide dismutase in the blood have not been shown to increase after SOD supplementation. Plant-based SOD seems to resist the rigors of the digestive tract, increasing the possibility of its absorption. (See also CATALASE.)

Asada, Kozi, and Yoshikawa, Toshikazu, eds. “”Frontiers of Reactive Oxygen Species in Biology and Medicine.”‘ Proceedings of the Sixth International Conference on Superoxide and Superoxide Dismutase, Kyoto, Japan. October 11-15, 1993. Exerpta Medica, Amsterdam (1994).

Catalase is highly active ENZYME that destroys HYDROGEN PEROXIDE. Catalase is considered an antioxidant. Hydrogen peroxide is a powerful oxidizing agent occurring naturally in cells as a by-product of metabolism that can damage cells. It is formed by specialized oxidative structures within cells called peroxisomes. Catalase is widely distributed among tissues and fluids such as SALIVA, and it is concentrated in the lens of the eye, where it serves a protective function. Commercially, catalase is applied in food processing to degrade excess hydrogen peroxide that is added as an oxidizing agent.