Antioxidant

From ArticleWorld

An antioxidant is a biological molecule that takes an oxidized molecule inside the body and reduces it to a normal healthy state. Several vitamins and nutrients in our diet serve as antioxidants.

Oxidation

Oxidized molecules are essentially positively electrically-charged, missing an electron that would make it electrically neutral. These molecules are called free radical molecules that become dangerous because they “steal” electrons from other molecules, causing the potential for tissue damage or damage to DNA, which can be cancer-forming. Free radical damage in the mitochondria of the cell (the energy-producing organelles) causes damage to the membranes and DNA inside the mitochondria. There are few DNA-repair mechanisms inside the mitochondria so that mitochondrial DNA is more easily damaged than nuclear DNA.

Oxidized molecules have beneficial effects on the body as well. Cells used to kill pathogens do so by releasing free radical agents to destroy the unwanted microorganism. Another free radical, nitrous oxide, is important in cell to cell signaling.

Exogenous antioxidants

Several things we eat or take as a supplement have antioxidant properties. Vitamins A, C and E are anti-oxidants, although using too much of these (especially vitamins A and E) can be toxic and can have the opposite of the desired effect. Synthetically made antioxidants have been designed in laboratories. Selenium is a beneficial antioxidant. Certain kinds of bio-flavenoids found in berries, green tea and specially roasted coffee contain antioxidant properties. Some food additives like pectin and ascorbic acids seem to have this property as well. The body makes antioxidant molecules on a regular basis. Finally, nutritional supplements like humic acid and beta-glucan are also antioxidants.

Mechanism of action

Antioxidants must deal with a situation where another molecule is not balanced electrically. To neutralize it, the antioxidant must either donate an extra electron to the molecule or bind to it in such a way that it is no longer destructive. Antioxidants are also called free radical scavengers, implying that they simply float around cleaning up oxidized debris. Some very good antioxidants, however, are limited in their ability to be taken up by mitochondria so that the mitochondrial-derived oxidized molecules are not as adequately removed. Vitamins C and E fall into that category.