Vitamins: anti-oxidant

Nutritional ingredients (e.g., relatively small molecules, such as carotenoids, (pro)vitamins, anti-oxidants, preservatives, polyunsaturated fatty acids, aspartame, and tailored peptide mixes). 

BARTH T J, ZOLER J, KUBELER A, BORN A I and OSSWALD H (1997) Redifferentiation of oral dysplasic mucosa by the application of the anti-oxidants beta-carotene, a-tocopherol and vitamin C. Int J Vitam Nutr Res 67(5) 368-76. 

Lipid characteristics. If the lipid becomes too unsaturated, the meat is not suitable for, for example, sausage production. Furthermore, products become oxidative unstable, accelerating rancidity problems, especially in many preheated catering products with an increased incidence of the development in warmed-over-flavour. Therefore, the anti-oxidative status of pork, for example content of vitamin, is an important technological quality criterion. 

Furthermore, mice treated with anti-oxidants (Vitamins C, or E, or beta-hydroxy toluene) prior to JP-8 dermal application exhibit a partial recovery in immune function... 

Sometimes, natural supplies and synthetic production lines are in competition. An example is /1-carotene (1), traditionally used as food colorant, but nowadays increasingly applied as a health ingredient anti-oxidant and vitamin A precursor [6],... 

Ascorbic acid or vitamin C is found in fruits, especially citrus fruits, and in fresh vegetables. Man is one of the few mammals unable to manufacture vitamin C in the liver. It is essential for the formation of collagen as it is a cofactor for the conversion of proline and lysine residues to hydroxyproline and hydroxylysine. It is also a cofactor for carnitine synthesis, for the conversion of folic acid to folinic acid and for the hydroxylation of dopamine to form norepinephrine. Being a lactone with two hydroxyl groups which can be oxidized to two keto groups forming dehydroascorbic acid, ascorbic acid is also an anti-oxidant. By reducing ferric iron to the ferrous state in the stomach, ascorbic acid promotes iron absorption. 

Vitamin C is one of a group of nutrients that includes vitamin E (see p. 389) and p-carotene (see p. 380), which are known as anti oxidants. Consumption of diets rich in these compounds is associ ated with a decreased incidence of some chronic diseases, such as coronary heart disease and certain cancers. However, clinical trials involving supplementation with the isolated antioxidants have failed to determine any convincing beneficial effects. 

Compounds that can scavenge radicals are also referred to as antioxidants. The best known anti-oxidants are vitamin C and vitamin E. Vitamin C is L-ascorbate (7.8), a good reducing agent that prevents oxidation of other molecules. The oxidized form of L-ascorbate is L-dehydroascorbic acid (7.9). Vitamin E is a mixture of a-, [3-, y-, and 8-tocopherol (7.10a-d). Of these four compounds, a-tocopherol is the most effective. Vitamin E is lipid-soluble and has the ability to disrupt the chain reaction during lipid peroxidation (see Chapter 2, Section 1.9). 

Aside from vitamins C and E many other compounds present in fruits and vegetables have been shown to have anti-oxidant properties. Among these compounds there are several classes of phenolic compounds. Aside from preventing scurvy these compounds have a positive influence on cardiovascular health. 

There is a third enzyme expressed in norepinephrine neurons that converts dopamine into more norepinephrine therefore, this enzyme is not expressed by dopamine neurons. The enzyme is stored within the synaptic vesicles and lies in wait for the entry of dopamine molecules once they have been synthesized in the cytoplasm of the neuron. In addition to this third enzyme, the vesicles contain copper and the anti-oxidant ascorbic acid, also known as Vitamin C. Copper is required for the enzyme to function appropriately. The ascorbic acid maintains the integrity of norepinephrine within the vesicle in the same way that ascorbic acid added to processed meats such as hotdogs... 

It should be noted that DNP use causes an increase in free radical production. Those who used DNP supplemented their diet with additional anti-oxidants such as vitamins C E, glutamine, and glutathione. 

Vitamin C (ascorbate) (Fig. 9.5) has the ability to act as a reducing agent, i.e. it will tend to reduce more reactive species. This ability to reduce Fe3+ to Fe2+may be important in promoting iron uptake in the gut. Oxidation of ascorbate by reaction with reactive oxygen species or reactive nitrogen species seems to lead to its depletion. In vitro, vitamin C can also exert pro-oxidant properties. Fe3+ can react with ascorbate to form Fe2+ and the semi-dehydroascorbate or ascorbyl radical. The latter can react with hydrogen peroxide to form Fe3+, the hydroxyl radical and a hydroxide anion. A key question with regard to the pro- or anti- oxidant effects of ascorbate may therefore be the availability of transition metal ions. Neurons main-... 

Ascorbic acid as a water-soluble vitamin (vitamin C) is an essential component in the human diet. As one of many anti-oxidants (vitamin E and 3-carotene are examples of fat-soluble anti-oxidants), ascorbic acid is required for the growth and repair of tissues in all parts of the body. It is necessary to form collagen, an important protein used to make skin, scar tissue, tendons, ligaments, and blood vessels. 

P-Carotene (Precursor of vitamin A and anti-oxidant) Figure 1.26 Examples of naturally occuring terpenes... 

We know it as Vitamin C, an anti-oxidant essential to human life. Photographers think of it as a secondary developing agent in superadditive pairs such as Metol-Ascorbate or Phenidone-Ascorbate. These have been known for years but recently made popular by Kodak XTOL film developer. 

But a photographic developer can be made without sulfite by substituting ascorbic acid, using Phenidone or metol, ascorbic acid, an alkali, and water. I learned of this quite by accident in 1993 when I ran out of sodium sulfite.The nearest supplier was a 100 mile round trip Knowing that ascorbic acid is an anti-oxidant and having some in my medicine closet I decided to chance it. My escapades that day were described in Darkroom and Creative Camera Techniques, Nov/Dec 1994 (reprinted on Ed Buffaloes s web site, www.unblinkingeye.com/articles, under Film and Film Developers Vitamin C Developers). 

A study on the photoprotective effect of the topical application of 2% vitamin E and 5% vitamin C in humans showed no effect with the application of each substance alone, but an enhanced photo-protective effect after applying vitamins E and C combined, which was attributed to the regeneration of vitamin E by vitamin C.20 This enhanced effect has also been shown with the topical application of a combination of 15% ascorbic acid and 1% a-tocopherol to porcine skin.21 The combined systemic supplementation of vitamins C and E was similarly able to reduce sunburn reactions22 and to increase the minimal erythema dose (MED), a measure for individual photosensitivity, more than supplementation with either vitamin E or vitamin C alone.23,24 An oral supplementation with an anti-oxidative combination of carotenoids (P-carotene and lycopene), vitamin C, vitamin E, selenium, and proanthocyanidins (Seresis , Pharmaton SA, Lugano, Switzerland) also reduced the development and grade of UVB-induced erythema 25... 

How can we keep our health against these reactive oxygen radicals Fortunately, vitamin C (hydrophilic), vitamin E (hydrophobic), flavonoids, and other polyphenols can function as anti-oxidants. These anti-oxidants are phenol derivatives. Phenol is a good hydrogen donor to trap the radical species and inhibits radical chain reactions. The formed phenoxyl radical is actually stabilized by the resonance effect as shown in eq. 1.8. Thus, phenol and polyphenol derivatives are excellent hydrogen donors to inhibit the radical reactions and, therefore, they are called radical inhibitors. 

Vitamin E, (tocopherols) C29H50O2 (Figure 6.8), which acts as an anti-oxidant to prevent the free radical oxidation of lipids in cell membranes. There are sufficient supplies of vitamin E in vegetable oils. 

Potential therapeutic benefits of antioxidants to reduce intracellular oxidative stress have not yet been evaluated in vasculific neuropathy associated w ith autoimmune disease. Such anti-oxidants as vitamin E, a-lipoic acid or benfotiamine may be effective in interrupting the pro-inflammatory transcription factors and subsequent NF-[kappa]B regulated cytokines that initiate and maintain inflammation associated w ith vasculific neuropathy (Haselbeck et al., 2004). 

Finally, one can note that interaction of camosine with superoxide does not result to such potentially toxic compound as H2O2, which takes place in the case of SOD. Thus, camosine can serve as effective hydrophylic anti-oxidant in excitable tissues in which relative deficit of such anti-oxidants as vitamin E (skeletal muscles) or catalase (brain) takes place. 

This pigment is highly soluble in all cell membranes and also very toxic hence, its excretion is one of the liver s most important functions. Interestingly, however, recent studies have demonstrated that bilirubin is an effective antioxidant of possible physiological importance. Along with urate and ascorbate (vitamin C), it is one of the three principal antioxidants in plasma. In membranes, its anti-oxidative efficacy rivals that of vitamin E. Thus, this toxic endproduct of a degradative pathway can also perform a beneficial function. 

The main thrust of the treatment is daily oxidation. In the morning, an antioxidant cream with vitamin E should be applied, and in the evening another anti-oxidant cream Renutriv ACE Lipoic Complex . 

Vitamin C owes its antioxidant properties to the fact that it reacts so readily with oxygen. When added to a food product, oxygen reacts preferentially with vitamin C, thereby sparing the food product from oxidation. Other anti-oxidant food additives include the synthetic compounds BHA and BHT and the natural antioxidant, vitamin E. 

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