Advertisement

Endogenous Antioxidants

  • Shabnum Nabi
Chapter

Abstract

An antioxidant is a molecule that inhibits the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When the chain reaction occurs in a cell, it can cause damage or death to the cell. Antioxidants terminate these chain reactions by removing free radical intermediates and inhibit other oxidation reactions. They do this by being oxidized themselves, so antioxidants are often reducing agents such as thiols, ascorbic acid, or polyphenols (Sies Helmut 1997). Antioxidants are vitamins, minerals, enzymes, or plant-derived nutrients called phytonutrients, found in food. They do what their name implies: antioxidation. Antioxidant means “against oxidation.” Antioxidants work to protect lipids from peroxidation by radicals. Antioxidants are effective because they are willing to give up their own electrons to free radicals. When a free radical gains the electron from an antioxidant, it no longer needs to attack the cell, and the chain reaction of oxidation is broken (Dekkers et al. 1996). After donating an electron, an antioxidant becomes a free radical by definition. Antioxidants in this state are not harmful because they have the ability to accommodate the change in electrons without becoming reactive. The human body has an elaborate antioxidant defense system. Antioxidants are manufactured within the body and can also be extracted from the food humans eat such as fruits, vegetables, seeds, nuts, meats, and oil. There are two lines of antioxidant defense within the cell. The first line, found in the fat-soluble cellular membrane, consists of vitamin E, beta-carotene, and coenzyme Q (Kaczmarski et al. 1999). Of these, vitamin E is considered the most potent chain-breaking antioxidant within the membrane of the cell. Inside the cell, water-soluble antioxidant scavengers are present. These include vitamin C, glutathione peroxidase, superoxide dismutase (SOD), and catalase (Dekkers et al. 1996).

Keywords

Superoxide Dismutase Internal Combustion Engine Glutathione Disulfide Induce Reactive Oxygen Species Production Mitochondrial Target Sequence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Aebi H (1984) Catalase in vitro. Methods Enzymol 105:121–126PubMedCrossRefGoogle Scholar
  2. Ariza ME, Bijur GN, Williams MV (1998) Lead and mercury metagenesis: role of H2O2, superoxide dismutase, and xanthine oxidase. Environ Mol Mutagen 31:352–361PubMedCrossRefGoogle Scholar
  3. Baillie JK, Thompson AAR, Irving JB, Bates MGD, Sutherland AI, MacNee W, Maxwell SRJ, Webb DJ (2009) Oral antioxidant supplementation does not prevent acute mountain sickness: double blind randomized placebo-controlled trial. QJM 102(5):341–348PubMedCrossRefGoogle Scholar
  4. Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C (2007) Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. JAMA 297(8):842–857PubMedCrossRefGoogle Scholar
  5. Boon EM, Downs A, Marcey D (2007) Catalase: H2O2: H2O2 oxidoreductase. Catalase structural tutorial textGoogle Scholar
  6. BRENDA (2009) The comprehensive enzyme information system. Department of Bioinformatics and Biochemistry, Technical University of Braunschweig, GermanyGoogle Scholar
  7. Carvalho MC, Franco JL, Ghizonia H, Kobusa K, Nazaria EM, Rocha JBT, Nogueira CW, Dafred AL, Mullera YMR, Farina M (2007) Effects of 2, 3-dimercapto-1-propanesulfonic acid (DMPS) on methylmercury-induced locomotor deficits and cerebellar toxicity in mice. Toxicology 239:195–203PubMedCrossRefGoogle Scholar
  8. Chelikani P, Fita I, Loewen PC (2004) Diversity of structures and properties among catalases. Cell Mol Life Sci 61:192–208PubMedCrossRefGoogle Scholar
  9. Clarkson TW (1997) The toxicity of mercury. Crit Rev Clin Lab Sci 34:369–403PubMedCrossRefGoogle Scholar
  10. Dabelstein W, Reglitzky A, Schütze A, Reders K. (2007) Automotive fuels. In: Ullmann’s encyclopedia of industrial chemistry, Wiley-VCH, Weinheim.Google Scholar
  11. Dekkers JC, Von Doormen LJP, Han CGK (1996) The role of antioxidant vitamins and enzymes in the prevention of exercise-induced muscle damage. Sports Med 21:213–238PubMedCrossRefGoogle Scholar
  12. Gaetani G, Ferraris A, Rolfo M, Mangerini R, Arena S, Kirkman H (1996) Predominant role of catalase in the disposal of hydrogen peroxide within human erythrocytes. Blood 87:1595–1599PubMedGoogle Scholar
  13. Goodsell DS (2004) Catalase. Molecule of the month. RCSB Protein Data BankGoogle Scholar
  14. Grotto D, Barcelos GRM, Valentini J, Antunes MGA, Angeli JPA, Garcia SC, Barbosa F (2009) Low levels of methylmercury induce DNA damage in rats: protective effects of selenium. Arch Toxicol 83:249–254PubMedCrossRefGoogle Scholar
  15. Ho YS, Xiong Y, Ma W, Spector A, Ho D (2004) Mice lacking catalase develop normally but show differential sensitivity to oxidant tissue injury. J Biol Chem 279:32804–32812PubMedCrossRefGoogle Scholar
  16. Hussain S, Atkinson A, Thompson SJ, Khan AT (1999) Accumulation of mercury and its effect on antioxidant enzymes in brain, liver, and kidneys of mice. J Environ Sci Health B 34:645–660PubMedCrossRefGoogle Scholar
  17. Jha P, Flather M, Lonn E, Farkouh M, Yusuf S (1995) The antioxidant vitamins and cardiovascular disease: a critical review of epidemiologic and clinical trial data. Ann Intern Med 123(11):860–872PubMedCrossRefGoogle Scholar
  18. Jina X, Loka E, Bondya G, Caldwella D, Muellera R, Kapala K, Cheryl A, Taylora M, Kubowc S, Mehtaa R, Chan HM (2007) Modulating effects of dietary fats on methylmercury toxicity and distribution in rats. Toxicology 230:22–44CrossRefGoogle Scholar
  19. Kaczmarski M, Wojicicki J, Samochowiee L, Dutkiewicz T, Sych Z (1999) The influence of exogenous antioxidants and physical exercise on some parameters associated with production and removal of free radicals. Pharmazie 54:303–306PubMedGoogle Scholar
  20. Lund BO, Miler DM, Woods JS (1991) Mercury-induced H2O2 formation and lipid peroxidation in vitro in rat kidney mitochondria. Biochem Pharmacol 42:181–187CrossRefGoogle Scholar
  21. Maehly A, Chance B (1954) The assay of catalases and peroxidases. Methods Biochem Anal 1:357–424PubMedCrossRefGoogle Scholar
  22. Pastore A, Piemonte F, Locatelli M, Lo Russo A, Gaeta LM, Tozzi G, Federici G (2003) Determination of blood total, reduced, and oxidized glutathione in pediatric subjects. Clin Chem 47:1467–1469Google Scholar
  23. Pompella A, Visvikis A, Paolicchi A, De Tata V, Casini AF (2003) The changing faces of glutathione, a cellular protagonist. Biochem Pharmacol 66:1499–1503PubMedCrossRefGoogle Scholar
  24. Sarafian TA (1999) Methylmercury-induced generation of free radical: biological implications. Met Ions Biol Syst 36:415–444PubMedGoogle Scholar
  25. Sies H (1997) Oxidative stress: oxidants and antioxidants. Exp Physiol 82(2):291–295PubMedGoogle Scholar
  26. Stringari J, Nunes AKC, Franco JL, Bohrer D, Garcia SC, Dafre AL, Milatovic D, Souza DO, Rocha JBT, Aschner M, Farina M (2008) Prenatal methylmercury exposure hampers glutathione antioxidant system ontogenesis and causes long-lasting oxidative stress in the mouse brain. Toxicol Appl Pharmacol 227:147–154PubMedCentralPubMedCrossRefGoogle Scholar
  27. Toner K, Sojka G, Ellis R (2007) A quantitative enzyme study; CATALASE. bucknell.edu

Copyright information

© Springer India 2014

Authors and Affiliations

  • Shabnum Nabi
    • 1
  1. 1.Interdisciplinary Brain Research Centre (IBRC) Jawaharlal Nehru Medical CollegeAligarh Muslim UniversityAligarhIndia

Personalised recommendations