Non-enzymatic antioxidants work by interrupting free radical chain reactions. Few examples of the non-enzymatic antioxidants are vitamin C, vitamin E, selenium, zinc, beta carotene, carotene, taurine, hypotaurine, and glutathione.
The non-enzymatic antioxidants are represented by molecules characterized by the ability to rapidly inactivate radicals and oxidants. Major intrinsic non-enzymatic antioxidants, which include metal-binding proteins (MBPs), glutathione (GSH), uric acid (UA), melatonin (MEL), bilirubin (BIL) and polyamines (PAs).
Metal-binding proteins (MBPs)
Metal-binding proteins (MBPs) such as transferrin (TF), ferritin (FER) and lactoferrin (LTF) are chelators of redox-active iron (Fe 2+), which can be effective free radical inhibitors in the Fenton reaction. In Fenton's reaction, the ferrous and/or ferric cation decomposes catalytically hydrogen peroxide to generate powerful oxidizing agents, capable of degrading a number of organic and inorganic substances.
Vitamin E
Since the discovery of vitamin E in 1920, it has been shown to be the most powerful membrane-bound antioxidant utilized by cells to scavenge reactive nitrogen and oxygen species with consequent disruption of oxidative damage to cell membrane phospholipids during cellular lipid peroxidation of the polyunsaturated fatty acids (PFA) and low-density lipoprotein (LDL).
Non-enzymatic antioxidants
