Free radicals are reactive atoms or molecules with at least one unpaired electron in the outer orbital. They are highly reactive, very aggressive, chemical oxygen molecules or organic compounds.
Major free reactive 02 species (ROS) and N species (RNS) are.
- Superoxide radical (O2-.)
- Hydroxyl radical (HO.)
- Nitric oxide radical (NO.).
As intermediates of metabolism, free radicals are constantly produced in every cell of the human body. The oxygen compounds with unpaired electrons are eager to snatch electrons from another atom or molecule. They react with these and form new radicals, which in turn also snatch electrons from other substances, and in a chain reaction there is a steady increase in the number of radicals in the body. As a result of this chain reaction, oxidative stress occurs when cellular antioxidant defenses are too low to compensate for the reactive oxygen radicals.
