Antioxidants recommendations

Table 10.3. Amine-type antioxidants recommended for polyolefins...

A sulfur synergist for phenolic antioxidants recommended primarily for in-service thermal stabilization of polyethylenes. 

A liquid sulfur synergist for phenolic antioxidants, recommended for ABS and SBR latex applications. 

Use of a good antioxidant is recommended for almost all neoprene compounds where color is not of importance, a staining antioxidant can be used. The substituted or hindered phenols, eg, Naugawhite (Uniroyal) and Antioxidant 2246 (American Cyanamid), are used where a minimum of product discoloration or staining is requited. 

Vitamin C occurs as L-ascorbic acid and dihydroascorbic acid in fruits, vegetables and potatoes, as well as in processed foods to which it has been added as an antioxidant. The only wholly undisputed function of vitamin C is the prevention of scurvy. Although this is the physiological rationale for the currently recommended intake levels, there is growing evidence that vitamin C may provide additional protective effects against other diseases including cancer, and the recommended dietary allowance (RDA) may be increased in the near future. Scurvy develops in adults whose habitual intake of vitamin C falls below 1 mg/d, and under experimental conditions 10 mg/d is sufficient to prevent or alleviate symptoms (Bartley et al., 1953). The RDA is 60 mg per day in the USA, but plasma levels of ascorbate do not achieve saturation until daily intakes reach around 100 mg (Bates et al., 1979). Most of the ascorbate in human diets is derived from natural sources, and consumers who eat five portions, or about 400-500 g, of fruits and vegetables per day could obtain as much as 200 mg of ascorbate. 

MCDERMOTT J H (2000) Antioxidant nutrients current dietary recommendations and research update , J Am Pharm Assoc, 40, 785. 

Oxidization of LDL-cholesterol is believed to play a significant role in the atherosclerotic process. The antioxidant vitamins, vitamin E and vitamin C, protect LDL cholesterol from oxidation. Evidence from observational and animal studies suggested that increased intake of antioxidant vitamins might inhibit the formation of atherosclerotic lesions and decrease the risk for cardiovascular events.40 However, several large, randomized, prospective studies found no beneficial effect of vitamin E or other antioxidants on cardiovascular outcomes in patients with IHD or IHD risk factors.41,42 Based on this evidence, current guidelines do not recommend supplementation with vitamin E or other antioxidants for the sole purpose of preventing cardiovascular events. 

N-acetylcysteine has antioxidant and mucolytic activity, which makes it a promising agent for COPD treatment, but clinical trials have produced conflicting results. One of the largest trials found N-acetylcysteine to be ineffective at reducing the decline in lung function and preventing exacerbations.29 Routine use cannot be recommended at this time. 

There is usually no need to supplement with specific vitamins. Patients should be encouraged to eat a well balanced diet and should also take a multivitamin and mineral supplement. Some clinicians recommend vitamins C and E for their antioxidant properties however, no significant improvements have been shown compared to placebo. Encourage patients to eat a diet rich in vitamin C and E (i.e., bright colored fruits and vegetables, nuts, and whole grains). Metabolism of levodopa may cause elevated homocysteine concentrations that... 

Coenzyme Q10 is an antioxidant essential for mitochondrial function. A dose of 1200 mg daily was associated with a slower decline in UPDRS scores than patients not receiving coenzyme Q10. Lower doses were no better than placebo, but the drug continues to be studied in doses up to 2400 mg daily. Many formulations contain vitamin E, and patients should not exceed recommended daily allowances of this vitamin, as bleeding times may be prolonged.42,43... 

Analysts in industry prefer in many cases to maintain consistent methods for their analyses. Recommended ASTM analytical procedures are quite well developed in the rubber and polymer industry. As an example, we mention the standard test method for determination of phenolic antioxidants and erucamide slip additives in LDPE using liquid chromatography [76]. However, the current industry standard test methods (ASTM, AOAC, IUPAC, etc.) use a large number of solvents in vast... 

Scheme 4.5 illustrates HPLCphase selection. Column manufacturers may have an applications database from which they can recommend a column and a method. Specific methods have been established for quite a large number of analytes, such as additives (e.g. antioxidants). Column selection and column technology have been reviewed [549]. Contrary to GC, and with the exception of SEC, selectivity in HPLC is determined not by the column alone but also by the mobile phase. There is therefore no one-for-one assignment between an analytical problem and the best column for this problem. 

Fluorescence is much more widely used for analysis than phosphorescence. Yet, the use of fluorescent detectors is limited to the restricted set of additives with fluorescent properties. Fluorescence detection is highly recommended for food analysis (e.g. vitamins), bioscience applications, and environmental analysis. As to poly-mer/additive analysis fluorescence and phosphorescence analysis of UV absorbers, optical brighteners, phenolic and aromatic amine antioxidants are most recurrent [25] with an extensive listing for 29 UVAs and AOs in an organic solvent medium at r.t. and 77 K by Kirkbright et al. [149]. 

The development of nontransmittable chronic illnesses is associated with the presence of oxidative agents in the body. These agents are found in air, water, or food or can be produced in the body s cells. Their high content in body cells causes an imbalance that results in oxidative stress damaging proteins, DNA, and others. As a result of this deterioration, an increase in the risk of nontransmittable chronic illnesses has been noted. In order to prevent or decrease oxidative stress, the consumption of foods rich in antioxidants, such as fruits and vegetables, is recommended (van Dokkum and others 2008 Liu 2003). 

It is of special interest that rheumatoid arthritis is one of the first examples of the extensive antioxidant treatment of human patients. In previous years the most recommended pharmaceutical antioxidant agent has been SOD. In 1986, Wilsman [245] reviewed the results of 10 years of presumably successful clinical experience with CuZnSOD treatment of inflammatory disorders including RA. Niwa et al. [246] recommended the application of liposomal... 

Various methods have been devised to prevent oxidation during storage. The most obvious is to store the LSD in nitrogen filled containers, but the excellent protection thus afforded is of course lost when the bottle or ampule is opened. Another method is to use an antioxidant Brown and Smith recommend ascorbic acid. A more sophisticated method, recommended on the highest authority, is to... 

The general rules that should therefore be observed include the use of a blanket of nitrogen whenever possible and evaporation of solvents at the lowest feasible temperatures, which must not exceed 50°C. The addition of an antioxidant such as butylated hydroxytoluene (2,6-di-/-butyl-4-methylphenol) to the extraction solvents (0.1 g 1 ) might be necessary to prevent deterioration of unsaturated lipids but it is essential for storage of lipid extracts at about 0.1% of the weight of lipid. Inactivation of lipolytic enzymes may usually be achieved by addition of an alcohol such as methanol or, in some cases, isopropanol. The latter is recommended for some more stable enzymes sometimes found in plant tissues. Alternatively the plant may be briefly immersed in boiling water. 

Most of the other medications studied to slow the course of Alzheimer s dementia presumably work as an antioxidant to protect nerve cells from damaging free radicals. Of the antioxidants, vitamin E is the safest and has the best evidence of efficacy. Thus, we recommend that all patients receive 2000 lU of vitamin E each day during... 

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