Antioxidant, carotene status

Kardinaal, A.E. et al.. Association between beta-carotene and acute myocardial infarction depends on polyunsaturated fatty acid status the EURAMIC study (European Study on Antioxidants, Myocardial Infarction, and Cancer of the Breast), Arterioscler. Thromb. Vase. Biol, 15, 726, 1995. 

Situnayake et al., 1991). No correlation between disease activity and serum vitamin E concentrations was found, but it was su ested that such patients might suffer a reduced antioxidant capacity. However, it is conceivable that a decreased serum antioxidant status is a primary event in the evolution of RA. Recent studies (Heliovaara etal., 1994) have demonstrated that lowered levels of vitamin E, /3-carotene and selenium (required for glutathione peroxidase) together may be a risk fector for subsequent development of RA. 

Erhardt, J. G., Mack, H., Sobeck, U., and Biesalski, H. K. (2002). p-Carotene and a-tocopherol concentration and antioxidant status in buccal mucosal cells and plasma after oral supplementation. Br. ]. Nutr. 87,471-475. 

SUV1MAX 7.5 yr 13,017 M-F Antioxidant supplementation reduces the risk of cancer in man no risk reduction in women. The baseline /3-carotene and vitamin C status was lower in men than in women. (205)... 

The involvement of oxidative stress in AD has opened a new door for potential therapeutic targets. In this regard, several antioxidants are currently in clinical trials such as Idebenone, a-Lipoic acid, acetyl-L-carnitine (ALC), vitamin E, vitamin C, flavonoids, P-carotene, gingko biloba, and metal-chelating agents. Idebenone is a metabolic antioxidant and is normally synthesized as part of the mitochondrial oxidative phosphorylation system. Improvements in clinical status after treatment with idebenone have been shown in a dose-dependent manner compared to placebo and tacrine (Thai et al., 2003). 

The scientific community has been discussing for quite some time now the relationship between oxidative stress, defined as the imbalance between oxidant and antioxidants [45], and the health-disease status. An impressive amount of information available in the literature deals with the effects of the classic antioxidants, ascorbic acid, a-tocopherol, and jS-carotene in a huge series of pathophysiological situations in experimental animals and humans. Concerning the effects of the classic antioxidants on mitochondrial function in situations of oxidative stress, the information is not so vast and most of the time it is not conclusive. However, substantial progress has been made in the description of the mitochondrial alterations in neurodegenerative diseases and in the a-tocopherol effects,both as prevention and as treatment [46]. We will briefly review some reports related to vitamin E and mitochondrial dysfunction in oxidative metaboHc disorders and in the neurodegenerative Alzheimer s and Parkinson s diseases. 

Decline in the overall antioxidant status due to a low intake of vitamin C, vitamin E, p-carotene, minerals (e.g., selenium), and other micronutrients based on age-related changes in food intake and digestion [18-20]... 

The applications surveyed in Tables 4 through 9 illustrate the general principles of vitamin E assays outlined in I.E. 1. Specifically, each matrix puts a different emphasis on the E vitamers to be determined. Thus, in serum/plasma a-tocoph-erol is clearly the main compound of interest. Accordingly, leversed-phase chromatography with UV detection is the indicated technique for this purpose. In addition, as part of the assessment of the antioxidant status of humans, tocopher-ols are determined concurrently with retinoids (retinol, retinyl palmitate) and carotenoids (particularly p-carotene). a-Tocopherol is also the principal target compound in erythrocytes and platelets but here, predictably, the quantitation of a-tocopherolquinone may also be meaningful as an indicator of oxidative stress (7). The need to assay this minor constituent in turn justifies coulometric detection. The analysis of tissues is complementary to that of plasma and red blood cells and mainly concerns the determination of a-tocopherol as well as retinoids, carotenoids, and ubiquinones (Table 6). 

Many of the randomized controlled trials (RCTs) investigating a protective role for antioxidant nutrients in cancer prevention (Table 3) have focused on / -carotene. A study in Linxian, China, of a rural population with poor nutritional status found that supplementation with a combination of / -carotene, selenium, and vitamin E for 5 years provided a 21% reduction in stomach cancer mortality and a 13% reduction in all cancer deaths. Although interesting, the population studied was likely to have very low intakes of a number of micronutrients and this study does not contribute to knowledge about the effects of individual antioxidants or offer any insight into their effects on populations with good nutritional status. 

---