Antioxidants are a highly effective group of protective agents that act to regulate oxidative reactions. Essential antioxidants are either endogenous (internally synthesized) or exogenous (consumed). They are often categorized as scavenger antioxidants and prevention antioxidants.

Scavenger antioxidants remove ROS and include small molecule antioxidants such as water soluble compounds like Vitamin C or glutathione and lipid soluble compounds such as vitamin E, carotenes, lipoic acid and Coenzyme Q. They also include large molecule enzyme antioxidants such as superoxide dismutase (SOD) that detoxifies the superoxide ion, catalase, which deals with hydrogen peroxide and glutatione peroxidase (GPx) which detoxifies cellular peroxides. These enzymes must be synthesized by cells and are subject to genetic and/or macromolecular regulatory mechanisms.

SOD first reduces (adds an electron) to the radical superoxide (O2-) to form hydrogen peroxide (H2O2) and Oxygen (O2). 2O2- + 2H —SOD >>>>>H2O2 + O2

Catalase and GPx then work with the protein glutathione to reduce hydrogen peroxide and produce water.

2H2O2 —CAT >>>>>H2O2 + O2

H2O2 + 2glutathione –GPx >>>>>oxidized glutathione + 2H2O

Preventative antioxidants hinder the formation of new ROS. These are proteins that bind ROS to protect essential proteins and include albumin, metallothionine, transferrin, cerulplasmin, and myoglobin.

It is important to note that many of these vitamins do not act in isolation from other antioxidants; rather, they are part of an interlinking set of redox aminoxidant cycles, termed the “antioxidant network.” For example, Vitamin E is efficiently reduced from its free radical form (tocotrienoxyl to tocopheroxyl) that arises after quenching lipid radicals to retun back to its native state (tocotrienol and tocopherol) by vitamin C. Vitamin C can regenerate vitamin E directly, while thiol antioxidants, such as glutatione and lipoic acid, can also regenerate vitamin E indirectly via vitamin C.

Oxidative stress is worsened in infection if micronutrients are deficient.

Markers for oxidative stress include 8-hydroxy-2′-deoxyguanosine.

Carotenoids are a class of yellow, orange and red plant derived compounds. All of the more than 600 known carotenoids are antioxidancts and about 50 are vitamins because they have provitamin A activity. Vitamin A refers to preformed retinol and the carotenoids that are coverted to retinol by cleavage of a central bond.

Flavonoids: are naturally occuring plant polyphenols found in abundance in diets rich in fruits, vegetables, and plant-derived beverages such as tea. They are well known to have antioxidant effects. Plant polyphenols have phenol rings that act as electron traps to scavenge peroxy radicals, superoxide anions, and hydroxyl radicals.

The antioxidant effects of tea polyphenols are considered to be associated with their ability to stimulate antioxidant defense metabolism through the redox-regulated transcription factors and mitogen-activated protein kinases (MAPK)-dependent cell cycle regulation.

–Blueberries: are very high in antioxidants.

–cranberry falvonoid contain anthocyanins and favonols, and have been found useful in the immune response to oxidize low-density lipoprotein (LDL) and its uptake by endothelial macropahges.

-Chili peppers are a food item found with many essential nutrients such as vitamin C, provitimains A and E and several B vitamins.

—Mushrooms: a high in antioxidants.

—Pure Cocoa: contains an abundance of polyphenols. However, there is also a lot of sufar and saturated fat found in chocalet bars.

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Vitamin E was discovered as a mcironutrient that is indispensable for reproduction in female rates. In humans, vitamin E deficiency can result in various neurological lesions.

Vitamin E is a fat soluble, like vitaimin A, and composed of a family of 8 related compounds, the tocopherols and tocotrienols. Vitamin E is a strong antioxidant that can support monocyte/macrophage mediated responses. Vitamin E can scavenge free radicals. It is considered one of the most potent fat soluble antioxidants due to its ability to donate electrons, hence interfering with the damaging effects of the oxidation process. It is needed in immune function and supplementation enhances cell mediated immunity in elderly patients. Research shown it plays an important role in the differentiation of immature T cells in the thymus, inducing higher differentiation that results in improved cellular immunity.

Vitmain E influances T cell function by downmodulating prostaglandin E2 in elderly subjects.

Viramin E can decrease serum levels of TNF-alpha and protein kinase C. TNF-alpha incdreases the activity of phospholipase A2. In monocytes, phospholipase A2 stimulates the replicaiton of HIV.

When supplementing with vitamin E, one should always consider selenium since these two nturients act synergistically.

The current RDI is 20 mg. Major dietary sources include salid oils, margarine, legumes and nuts. The immunostimulating effect of vitamin E can usually be acheived by administering 200-800 mg of vitamin E daily. Vitamin E reduces hydrogen peroxide which is used especially by neutrophils to kill microorganisms. So that excessively high use could reduce bactericidal and proliferative activity of periopheral leukocytes.