Superoxide Dismutase (SOD)
Superoxide radicals are formed in a number of metabolic reactions, including lipid peroxidation initiated by light or metal ions. This process is the cause of rancidity of oils, but it also happens in live tissues. One of the reasons why the superoxide radicals are so dangerous is because they start chain reactions where more and more free radicals are formed, reacting with all cell constituents and wreaking havoc wherever they go. In the human body, the main chain breaking antioxidants are the water soluble superoxide dismutase (SOD) and the lipid soluble alpha-D-tocopherol (vitamin E). In our cells, we have our own SODs, but we can protect our skin by supplementing them with topically applied SOD. The role of SOD is to eliminate the free radicals resulting from lipid peroxidation and to prevent the chain reactions that would eventually reach deeply into the skin.