Update on the Biological Characteristics of the Antioxidant Micronutrients: Vitamin C, Vitamin E, and the Carotenoids
Section snippets
The Antioxidant Hypothesis
Interest in the antioxidants stems from the growing understanding that a substantial number of free radicals are generated as an ordinary process of oxygen metabolism and that a wide range of conditions are associated with either an excess generation of free radicals or an inadequate antioxidant defense system (5). Exogenous sources, such as radiation, air pollution, and smoking, can also generate free radicals. Free radicals are reactive chemical species that contain one or more unpaired
Chemistry and Analysis
Vitamin C is the generic descriptor for all compounds exhibiting qualitatively the biological activity of ascorbic acid, which includes the oxidized form, dehydroascorbic acid (DHAA). Isoascorbic (erythorbic) acid, which is used widely as a food preservative, possesses antioxidant properties similar to L-ascorbic acid but lacks antiscorbutic activity (29). The newer high-performance liquid chromatography (HPLC) methods for quantifying vitamin C in biological specimens, foods, and
Chemistry and Analysis
Vitamin E is the generic term used to describe a group of at least eight compounds that exhibit the biological activity of a-tocopherol. The group comprises α-, β-, γ-, and δ-tocopherol and α-, β-, γ-, and δ-tocotrienol. All of these compounds occur as a variety of isomers; for example, eight stereoisomers of α-tocopherol result from the synthesis of this compound. The natural isomeric form is RRR-α-tocopheiol (also known as d-α-tocopherol), and the synthetic form is described as all racemic or
Chemistry and Analysis
Carotenoids are pigments that are found in plants and microorganisms but are not synthesized in animals. Nearly 600 of these compounds have been identified (see Fig. 2) (2), (78), and less than 10% of these compounds can be metabolized to retinol and function as vitamin A precursors in mammals. Human plasma contains only a fraction of the total carotenoids that have been identified in the food supply (79), The predominant plasma carotenoids are lutein, β-cryptoxanthin, lyco-pene, oc-carotene,
References (128)
A review of epidemiologic evidence that carotenoids reduce the risk of cancer
J Nutr.
(1989)Biological actions of carotenoids
J Nutr.
(1989)- et al.
Antioxidant defense systemsthe role of carotenoids, tocopherols, and thiols
Am J Clin Nutr.
(1991) - et al.
Effects of flavonoids on non-enzymatic lipid peroxidationstructure activity relationship
Biochem Med Me tab Biol,
(1988) - et al.
Antioxidant vitamins and low-density-lipoprotein oxidation
Am J Clin Nutr.
(1993) Free radicals, antioxidant enzymes, and carcinogenesis
Free Radic Biol Med.
(1990)Carotenoids and canceran update with emphasis on human intervention studies
Eur J Cancer.
(1993)Free radicals and diabetes
Free Radic Biol Med.
(1988)Antioxidants and eye disease
Am J Med.
(1994)Studies evaluating antioxidants and beta-carotene as chemopreventives
Am J Clin Nutr.
(1991)
Ascorbic acid and erythorbic acid metabolism in nonpregnant women
Am J Clin Nutr.
Comparative bioavailability to humans of ascorbic acid alone or in a citrus extract
Am J Clin Nutr.
Assessment of human vitamin C status
J Nutr.
Steady-state turnover and body pool of ascorbic acid in man
Am J Clin Nutr.
Dose-dependent absorption and excretion of vitamin C in humans
Int J Pharm.
Nonenzymatic degradation and salvage of dietary folatephysiocochemical factors likely to influence bioavailability
Bio chem Molecular Med.
Effect of mega doses of vitamin C on bactericidal activity of leukocytes
Am J Clin Nutr.
Immunologic modulation by vitamin C in the elderly
Int J Immunopharmacol.
The antioxidant role of vitamin C
Adv Free Radio Biol Med.
Inhibitory effects of ascorbic acid on growth of leukemic and lymphoma cell lines
Cancer Lett.
Simultaneous determination of alpha tocopherol and retinol in plasma or red cells by high pressure liquid chromatography
Am J Clin Nutr.
Relative bioavailability of RRR- and all-rac-alpha-tocopheryl acetate in humansstudies using deuterated compounds
Am J Clin Nutr.
Vitamin E intakes and sources in the United States
Am J Clin Nutr.
Identification, purification, and immunochemical characterization of a tocopherol-binding protein in rat liver cytosol
J Lipid Res.
Preferential incorporation of alpha-tocopherol vs gamma-tocopherol in human lipoproteins
Am J Clin Nutr.
RRR- and SRR-alpha-tocopherols are secreted without discrimination in human chylo-microns, but RRR-alpha-tocopherol is preferentially secreted in very low density lipoproteins
J Lipid Res.
Human adipose alpha-tocopherol and gamma-tocopherol kinetics during and after 1 y of alpha-tocopherol supplementation
Am J Clin Nutr.
Role of vitamin E in preventing the oxidation of low-density lipoprotein
Am J Clin Nutr.
McCollum Award Lecture, 1992vitamin A absorption, transport, cellular uptake, and storage
Am J Clin Nutr.
Carotenoid content of fruits and vegetablesan evaluation of analytic data
J Am Diet Assoc.
The development and application of a carotenoid database for fruits, vegetables, and selected multicomponent foods
J Am Diet Assoc.
Carotenoid absorption in humans
Methods Enzymol.
Carotene balances on boys in Ruanda where vitamin A deficiency is prevalent
J Nutr.
Bioavailability of beta-carotene in humans
Am J Clin Nutr.
Beta-carotene accumulation in serum and skin
Am J Clin Nutr.
Plasma carotenoids in normal men after a single ingestion of vegetables or purified beta-carotene
Am J Clin Nutr.
Plasma carotenoid response in men to chronic intake of selected foods and beta-carotene supplements
Am J Clin Nutr.
Plasma beta-carotene response in humans after meals supplemented with dietary pectin
Am J Clin Nutr.
Enzymatic conversion of beta-carotene into beta-apo-carotenals and retinoids by human, monkey, ferret, and rat tissues
Arch Biochem Biophys.
Carotene cleavage activity in bovine ovarian follicles
Theriogenology.
Actions of carotenoids in biological systems
Ann Rev Nutr.
An introduction to free radical chemistry
Br Med Bull
Oxidants, antioxidants, and the degenerative diseases of aging
Proc Nail Acad Sci U S A.
Mechanism of action of biological antioxidants
Proc Soc Exp Biol Med.
Oxidative stressintroduction
Free radical tissue damageprotective role of antioxidant nutrients
FASEB J.
Anticarcinogenic effect of common carotenoids
Int J Vitamin Nutr Res.
Free radicals, antioxidants, and human diseasewhere are we now?
J Lab Clin Med.
Liver damage due to free radicals
Br Med Bull.
Free radicals and myocardial reperfusion injury
Br Med Bull.
Cited by (265)
The landscape of potential health benefits of carotenoids as natural supportive therapeutics in protecting against Coronavirus infection
2022, Biomedicine and PharmacotherapyVitamin C and its therapeutic potential in the management of COVID19
2022, Clinical Nutrition ESPENSolvent polarizability modulated the electronic state of conjugated long-chain polyene molecules by DFT
2022, Journal of Molecular LiquidsPotassium bromate-induced oxidative stress, genotoxicity and cytotoxicity in the blood and liver cells of mice
2022, Mutation Research - Genetic Toxicology and Environmental MutagenesisThe association of oral function with dietary intake and nutritional status among older adults: Latest evidence from epidemiological studies
2021, Japanese Dental Science Review