Catalase is an antioxidant enzyme found in living organisms that changes hydrogen peroxide to water and oxygen. Hydrogen peroxide is formed as a toxic waste product of metabolism. It must be quickly converted into other, less dangerous, chemicals. To manage this problem, the enzyme catalase is frequently used to rapidly catalyse the decomposition of hydrogen peroxide into harmless oxygen and water. In aerobic cells, free radicals are constantly produced mostly as reactive oxygen species. Once produced, free radicals are removed by antioxidant defenses including the enzymes catalase, glutathione peroxidase, and superoxide dismutase. There is a glutathione supplement available for sale. Reactive oxygen species, including nitric oxide and related species, commonly exert a series of useful physiological effects. However, imbalance between prooxidant and antioxidant defenses in favor of prooxidants results in oxidative stress. This results in damage to lipids, proteins, and nucleic acids. Alone or in combination with primary factors, free radicals are involved in the cause of hundreds of diseases.

Supplementation
Q. Where can I buy catalyse enzyme and how much would you take on a daily basis?
   A. I have not seen any human studies giving catalase pills and how effective they are and in what dosage. Therefore it is difficult to know whether taking a catalase supplement in pill form has a positive effect and if so how many milligrams are optimal. If you do wish to purchase such a product, Enzymedica, Free Radical Defenze, 60 Capsules is one option although I am not sure how effective any of these products are since human testing is quite limited. For the time being I prefer free radical scavengers such as carnosine, aceytylcysteine, alpha lipoic acid, acetyl l-carnitine, and other antioxidants.

Research study
Mice genetically engineered to produce a human antioxidant enzyme lived longer than normal mice, which points to the possibility that antioxidants can counteract the effects of aging and disease. Chemicals known as free radicals damage cells by generating a reaction called oxidation - the same process that causes metal to rust. Antioxidants interfere with this chemical reaction. Researchers at the University of Washington School of Medicine used genetically engineered mice that made extra amounts of catalase. The mice were precisely designed to produce extra catalase in certain areas of the body - the cells' cytoplasm; the nucleus where DNA is stored; and the mitochondria, the cell's power plant and also a place where some DNA is found. The mice that made more catalase in the mitochondria lived about 20 percent longer - about five months. The mice with more catalase levels in the nucleus and cytoplasm lived only a little longer than normal mice. They also had healthier heart muscle tissue, indicating the catalase helped protect from age-related heart problems seen in normal mice.

Supplements that can raise levels
J Nat Sci Biol Med. 2015. Antioxidant and protective effects of Phytocee (™) against carbon tetrachloride-induced oxidative stress. This study evaluated the antioxidant potential of a polyherbal formulation Phytocee in the rodent model. Four groups of rats (n = 6) were pretreated with Vitamin C (20 mg/kg) or Phytocee (20, 100, and 200 mg/kg), respectively for 10 days. Oxidative stress in rat liver was induced by administration of carbon tetrachloride (CCl4) at 2 ml/kg as a single dose orally to all groups except the vehicle control group. After 24 h of administration of CCl4, hepatic levels of malondialdehyde (MDA), serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic superoxide dismutase (SOD), catalase, and reduced glutathione (GSH) levels were evaluated. Phytocee administered groups at all the dose levels significantly reduced the hepatic MDA, serum ALT and AST levels with a marked increase in hepatic SOD and catalase as compared with CCl4 treated group.