Antioxidants often work synergistically by recycling other antioxidant nutrients that have been oxidized or have already been used in the neutralization of free radicals.
Vitamins C, E, and the trace mineral selenium, have this synergistic activity but also have significant anti-inflammatory activity, which helps stimulate the repair of damaged tissue.
Vitamin C is a six carbon water-soluble compound that is important for connective tissue growth, the conversion of cholesterol to bile salts, and the protection of other vitamins and certain fats from oxidation. Vitamin C protects collagen destruction and aids in cross linking reactions.
Vitamin C is also known as ascorbate or ascorbic acid. Vitamin C promotes wound healing and strengthens and stabilizes blood vessels, joints, gums, and connective tissue.
Vitamin C also serves as an important antioxidant that helps prevent oxidative damage to important structures in the body.
Ascorbic acid or Vitamin C is a water-soluble, chain-breaking antioxidant that reacts with superoxide and hydroxyl radicals, as well as the reactive singlet oxygen.
Vitamin C or Ascorbate can also regenerate alpha-tocopherol from its oxidized form, thus allowing vitamin E to continue its role in quenching free radicals.
It has been suggested that many of the beneficial effects, related to vitamin C may be due to this protective enhancement of tocopherol and the antioxidant, beta-carotene.
Vitamin C’s antioxidant activity also protects against air borne pollutants and supports drug detoxification by the liver.
Vitamin C has been shown to suppress the formation of nitrosamines (a carcinogen), which is known to cause cancer.
Both Vitamin C and vitamin E have important role in repressing inflammation. Vitamin C’s role is to stabilizes cell membranes and promote the hydroxylation of anti-inflammatory steroids (cortisol). The end result is to suppress the body’s response to injury.
Vitamin E on the other hand, inhibits platelet aggregation due to its causing a reduction in cyclooxygenase activity. Vitamin E inhibits enlargement of the area of inflammation but does not suppress the inflammation that is already in progress.
Selenium (Se) is a trace mineral and part of the enzyme glutathione peroxidase. The enzyme glutathione is made up of three amino acids. Its role is to aid liver cells in the process of detoxification. Selenium has come under intense investigation recently as part of a dietary strategy to prevent cancer. Selenium is also administered to newly infected HIV patients due to its inhibition of reverse transcriptase in RNA-virus infections.
Glutathione peroxidase destroys the molecule, hydrogen peroxide, before it can oxidize molecules and create destructive free radicals. Hydrogen peroxide is produced by macrophages in order to destroy microorganism when it releases molecular oxygen. Hydrogen peroxide and oxygen are also produced as a by-product of another antioxidant system, superoxide dismutase.
Superoxide dismutase (SOD) is an enzyme that contains manganese (Mn) in the mitochondria but is copper/zinc (Cu/Zn) enzyme in the cytoplasm. These metals help provide the enzyme with molecular protection against free radicals. SOD destroys the superoxide radical, a very reactive free radical. In doing so it produces hydrogen peroxide, which requires neutralization with glutathione peroxidase. Together they minimize, prevent and neutralize the oxidative damage targeted at the exposed lipids in cell membranes.
Oxidative stress occurs when there is free radical saturation and not enough antioxidants to quench the reactive oxygen species. This process is mplicated in the pathogenesis of disease.
Reactive oxygen species are produced during normal cellular processes. Their amounts are controlled by antioxidants and enzymatic scavengers. When free radical production exceeds antioxidant capacity,damage to proteins, lipids, and DNA occurs. Many avenues contribute to free-radical formation, including the electron transport chain in mitochondria and the inflammatory signaling process as well as the endoplasmic reticulum stress due to protein chemistry.
The electron transport system is the major source of superoxides. As electrons pass through the chain, a small fraction escape and prematurely react with molecular oxygen resulting in the production of superoxide.