Carotene alpha

GAMBOA-PINTO A J, ROCK C L, FERRUZZI M G, SCHOWINSKY A B and SCHWARTZ S J (1998) Cervical tissue and plasma concentrations of alpha-carotene and beta-carotene in women are correlated. /iVMtr. 128(11) 1933-6. 

Levy, J., E. Bosin, B. Feldman et al. 1995. Lycopene is a more potent inhibitor of human cancer cell proliferation than either alpha-carotene or beta-carotene. Nutr Cancer 24(3) 257-266. 

Roodenburg AJ, Leenen R, van het Hof KH, Weststrate JA and Tijburg LB. 2000. Amount of fat in the diet affects bioavailability of lutein esters but not of alpha-carotene, beta-carotene and vitamin E in humans. Am J Clin Nutr 71 1187-1193. 

Cuscuta australis R. Brown Dou Tu Si (Dodder) (seed, aerial part) Carotenoids, alpha-carotene-5, 6-epoxide, taraxanthin, lutein.48 For fever, constipation, diuretic. 

Some non-enzymatic antioxidants play a key role in these defense mechanisms. These are often vitamins (A, C, E, K), minerals (zinc, selenium), caretenoids, organosulfur compounds, allyl sulfide, indoles, antioxidant cofactors (coenzyme Qio)> and polyphenols (flavonoids and phenolic acids) [1,37]. Further, there is good evidence that bilirubin and uric acid can act as antioxidants to help neutralize certain free radicals [38]. Alpha-carotene, lycopene, lutein, and zeaxanthine [39] can be considered subgroups of carotenoids [40] that are effective antioxidant compounds. 

A concern has been raised that phytosterol doses that are effective for cholesterol reduction may impair the absorption and lower blood concentrations of fat-soluble vitamins and antioxidants. A number of studies showed that phytosterols had no effect on plasma concentrations of vitamin D, retinol, or plasma-lipid-standardized alpha-tocopherol. Moreover, the reports of the effect of phytosterols on concentrations of blood carotenoids (lutein, lycopene, and alpha-carotene) are controversial. There seems to be general agreement that phytosterol doses >1 g/d significantly decrease LDL-C standardized beta-carotene concentrations however, it remains to be determined whether a reported 15-20% reduction in beta-carotene due to phytosterol supplementation is associated with adverse health effects. Noakes et al. found that consumption of one or more carotenoid-rich vegetable or fruit servings a day was sufficient to prevent lowering of plasma carotenoid concentrations in 46 subjects with hypercholesterolemia treated with 2.3 g of either sterol or stanol esters. 

Vitamin A is a family of fat-soluble vitamins, of which retinol is the most active form. Beta-carotene is a provitamin carotenoid that is converted to retinol more efficiently than other provitamin carotenoids. Other provitamin carotenoids include alpha-carotene and (trivial names) b-cryptoxanthin, lycopene, lutein, and zeaxanthin they are widely available in foods. 

Thurnham DI, Smith E, Flora PS. Concurrent liquid-chromatographic assay of retinol, alpha-tocopherol, beta-carotene, alpha-carotene, lycopene, and bet l-cryptoxanthin in plasma, with tocopherol acetate as internal standard. Clin Chem 1988 34 377-81. 

T Hagiwara, T Yasuno, K Funayama, SJ Suzuki. Determination of lycopene, alpha-carotene and beta-carotene in serum by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry with selected-ion monitoring. J. Chromatogr B Biomed 708 67—73, 1998. 

Fig. 5.3 Carotenoid biosynthesis in maize endosperm. Compounds IPP, isopentenyl pyrophosphate FPP, famesyl pyrophosphate GGPP, geranylgeranyl pyrophosphate DMAPP, dimethallyl pyrophosphate. Carotenoid biosynthetic pathway enzymes PSY, phytoene synthase PDS, phytoene desaturase ZDS, zetacarotene desaturase ISO, carotene isomerase LCY-B, lycopene beta cyclase LCY-E, lycopene epsilon cyclase HYD-B, beta-carotene hydroxylase HYD-E, alpha-carotene hydroxylase Isonrenoid biosynthetic pathway enzymes IPPI (IPP isomerase) GGPPS (GGPP synthase). Structures are not representative of the geometrical isomer substrates (e.g. Z-phytoene is a bent structure).

Compared to other fruits and vegetable, carotenoid accumulation in maize endosperm is orders of magnitude lowerThe primary compounds accumulating are zeaxanthin and lutein, the ratio of which is highly variable and further accompanied by smaller amounts of the provitamin A compounds, alpha-carotene, betacarotene, and betacryptoxanthin. The earlier pathway intermediates are generally not detected, unless there is a mutation conferring a block in the pathway but which... 

Antioxidants derived from foods help to protect against free radical damage. Carotenoids are a very important class of antioxidants, as are vitamins A, C, and E. Carotenoids, including alpha carotene, beta carotene, lycopene, lutein, and zexanthin, have been demonstrated to protect against skin cancer, prostate cancer, and atherosclerosis, among others. Higher blood antioxidant levels have been correlated with lower blood levels of C-reactive protein (CRP), and thus lower inflammation of the blood vessels (and less atherosclerotic plaque). 

Alpha-carotene Beta-carotene Beta-cryptoxanthin Lycopene Lutein -i- zeaxanthin... 

Alpha carotene Carrots, sweet potatoes, pumpkin, winter squash, broccoli, peas, spinach, turnips, lettuce Neutralizes free radicals that may cause damage to cells, boosts cellular antioxidant defenses, protects cornea against UV light... 

Drescher, J. N., Sherma, J., and Fried, B. (1993). Thin layer chromatographic determination of alpha-carotene on magnesium oxide layers. J. Liq. Chromatogr. 16 3557-... 

JR Zhou, ET Gugger, JW Erdman Jr. The crystalline form of carotenes and the food matrix in carrot root decrease the relative bioavailabihty of beta- and alpha-carotene in the ferret model. J Am CoU Nutr 15 84-91, 1996. 

A Homnava, J Payne, P Koehler, R Eitenmiller. Provitamin A (alpha-carotene, beta-carotene and beta-cryptoxanthin) and ascorbic acid content of Japanese and American persimmons. J Food Qual 13 85-95, 1990. 

In addition to the actual forms of vitamin A, related compounds, known as carotenes, are found in several fruits and vegetables. Carotene is also called (1) provitamin A, because it can be converted to vitamin A in the body and (2) precursor of vitamin A, because it precedes vitamin A. At least 10 of the carotenoids found in plants can be converted with varying efficiencies into vitamin A. Four of these carotenoids alpha-carotene, beta-carotene, gamma-carotene, and crypto-xanthine (the main carotenoid of corn)—are of particular importance due to their provitamin A activity. Of the four, beta-carotene (see Fig. V-25) has the highest vitamin A activity and provides about two-thirds of the vitamin A necessary for human nutrition. 

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