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• Provides key nutrients needed by the  body to neutralize free radicals.• Helps protect against cellular damage.  May exh...
   Slow or prevent damage to body cells   May improve immune function and lower risk    for infection and cancer   Caro...
Free Radical Diseases                         Alzheimer’s   Stroke                         Parkinson’s        Photo-aging ...
The free radical diseases•Cancer initiation and promotion isassociated with chromosomal defectsand oncogene activation. It...
The free radical diseases•Atherosclerosis may be due to freeradical reactions involving diet-derivedlipids in the arterial...
Antioxidants•vitamin E•vitamin C•carotenoids
vitamin E•Vitamin E is a fat-soluble substancepresent in all cellular membranes and ismainly stored in adipose tissue, the...
Vitamin E and cancer•Besides being a free radical scavenger,vitamin E at high intakes enhances thebodys immune responses. ...
Vitamin E and   cardiovascular disease•Vitamin E intakes are associated withlowered risk of angina and mortality fromheart...
Vitamin E and neurological        disorders•Supplementation with vitamin C andE might be of benefit in slowing theprogress...
Vitamin C•Vitamin C, or ascorbic acid, is a water-soluble vitamin. This vitamin is a freeradical scavenger, it is consider...
Vitamin C and cancer•Vitamin C is effective in protecting tissuesagainst oxidative damage. It suppresses theformation of c...
Vitamin C and    cardiovascular disease•Vitamin C may lower total cholesterol inthe blood, thus reducing the risk ofcardio...
Vitamin C and cataracts•High intake of fruits and vegetableswhich are rich sources of ascorbic acidappear to be protective...
Carotenoids•Carotenoids are a group of red, orangeand yellow pigments found in plantfoods, particularly fruits and vegetab...
Superoxide Dismutase (SOD) is   essential for the body and is: A metalloprotein – containing several sub units       organ...
SOD acts at the source. It is the first and one of themajor components of the body’s antioxidant system.SOD is a powerful ...
Reactive oxygen species:     formation of secondary free radicalsHydroxyl radical induces the formation ofsecondary free r...
Pro-Oxidants                                 Antioxidants(Reactive Oxygen SpeciesFree Radicals)                      OXIDA...
Antioxidant systems:         the primary antioxidantsThe primary antioxidants:    • are endogenous molecules    • act at t...
Antioxidant systems:       the secondary antioxidantsThe secondary antioxidants    • are exogenous molecules, carried by  ...
Oxidants and antioxidants              in the bodyUnder normal circumstances andconditions, the body’s endogenousantioxida...
Oxidative stress…  …is the result of an imbalance between oxidant and antioxidant            production     increase of fr...
Oxidative stress: consequencesA break in the equilibrium caused by…            • UVA and B            • Stress, overwork, ...
                           Lipid                                               L•                                        ...
The fight against       secondary free radicals……occurs with the secondary antioxidants  (vitamins A,C, E, polyphenols etc...
Secondary antioxidants are vital but just slow down the oxidative              stress– we need to do something extra…
Functions of Pentose Phosphate Pathway 1) NADPH for biosynthetic pathways (e.g.,    synthesis of fatty acids and cholester...
Table 1. Reactive Oxygen Species             and Antioxidants that Reduce ThemReactive Species         AntioxidantSinglet ...
H2O2          glutathione        2 H2O                        peroxidase                                            GSSG  ...
SUMMARY OF ANTI-OXIDANT ENZYMESGlutathione peroxidase: 2 GSH + H2O2  GSSG + 2 H2OUses selenium as a cofactorCatalase : 2 ...
NUTRITIONAL CORRELATE: SELENIUM selenocysteine in glutathione peroxidase intake may be related to lower cancer mortality...
lipid peroxyl radical                         Figure 7. Antioxidant cascade          LOO•      rxn 5       LOOH           ...
Medical Scenario:If the antioxidant protective system in the redblood cell becomes defective, hemolyticanemia occurs; that...
Antioxidants
Antioxidants
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Antioxidants

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  • So what is the best way to work with Geon and our exciting new product range – as a customer or as a business owner? As one of our associates – a business owner – you get all the products at wholesale prices, enjoy tax advantages, and now have a plan to create wealth So if being a business owner makes sense…
  • So what is the best way to work with Geon and our exciting new product range – as a customer or as a business owner? As one of our associates – a business owner – you get all the products at wholesale prices, enjoy tax advantages, and now have a plan to create wealth So if being a business owner makes sense…
  • So what is the best way to work with Geon and our exciting new product range – as a customer or as a business owner? As one of our associates – a business owner – you get all the products at wholesale prices, enjoy tax advantages, and now have a plan to create wealth So if being a business owner makes sense…
  • So what is the best way to work with Geon and our exciting new product range – as a customer or as a business owner? As one of our associates – a business owner – you get all the products at wholesale prices, enjoy tax advantages, and now have a plan to create wealth So if being a business owner makes sense…
  • So what is the best way to work with Geon and our exciting new product range – as a customer or as a business owner? As one of our associates – a business owner – you get all the products at wholesale prices, enjoy tax advantages, and now have a plan to create wealth So if being a business owner makes sense…
  • So what is the best way to work with Geon and our exciting new product range – as a customer or as a business owner? As one of our associates – a business owner – you get all the products at wholesale prices, enjoy tax advantages, and now have a plan to create wealth So if being a business owner makes sense…
  • So what is the best way to work with Geon and our exciting new product range – as a customer or as a business owner? As one of our associates – a business owner – you get all the products at wholesale prices, enjoy tax advantages, and now have a plan to create wealth So if being a business owner makes sense…
  • So what is the best way to work with Geon and our exciting new product range – as a customer or as a business owner? As one of our associates – a business owner – you get all the products at wholesale prices, enjoy tax advantages, and now have a plan to create wealth So if being a business owner makes sense…
  • Transcript of "Antioxidants"

    1. 1. • Provides key nutrients needed by the body to neutralize free radicals.• Helps protect against cellular damage. May exhibit anti-aging benefits.• Super ORAC (Primary) Antioxidants are the body’s own natural defense against free radicals.• They scavenge or ‘mop’ them up before they have a chance to harm cells.
    2. 2.  Slow or prevent damage to body cells May improve immune function and lower risk for infection and cancer Carotenoids – beta carotene (familiar) Vitamin C Vitamin E Found in colorful fruits/veggies and grains
    3. 3. Free Radical Diseases Alzheimer’s Stroke Parkinson’s Photo-aging (wrinkles) Macular Degeneration & Cataracts Periodontitis Emphysema Lung Cancer Coronary Heart Disease Diabetes Hypertension & Alcohol & Chronic Kidney Disease Viral Liver Diseases Prostate Cancer Rheumatoid Arthritis Colo-rectal CancerPeripheral Vascular Disease Skin Cancer & Osteoarthritis Melanoma
    4. 4. The free radical diseases•Cancer initiation and promotion isassociated with chromosomal defectsand oncogene activation. It is possiblethat endogenous free radical reactions,like those initiated by ionizing radiation,may result in tumour formation.
    5. 5. The free radical diseases•Atherosclerosis may be due to freeradical reactions involving diet-derivedlipids in the arterial wall and serum toyield peroxides and other substances.These compounds induce endothelialcell injury and produce changes in thearterial walls .
    6. 6. Antioxidants•vitamin E•vitamin C•carotenoids
    7. 7. vitamin E•Vitamin E is a fat-soluble substancepresent in all cellular membranes and ismainly stored in adipose tissue, the liverand muscle. Vitamin E is a principalantioxidant in the body and protectspolyunsaturated fatty acids in cellmembranes from peroxidation.
    8. 8. Vitamin E and cancer•Besides being a free radical scavenger,vitamin E at high intakes enhances thebodys immune responses. Vitamin E alsoinhibits the conversion of nitrites in thestomach to nitrosamines, which arecancer promoters.
    9. 9. Vitamin E and cardiovascular disease•Vitamin E intakes are associated withlowered risk of angina and mortality fromheart disease.
    10. 10. Vitamin E and neurological disorders•Supplementation with vitamin C andE might be of benefit in slowing theprogression of Parkinsons disease.
    11. 11. Vitamin C•Vitamin C, or ascorbic acid, is a water-soluble vitamin. This vitamin is a freeradical scavenger, it is considered to beone of the most important antioxidants inextra cellular fluids. Its protective effectsextend to cancer, coronary artery disease,arthritis and aging.
    12. 12. Vitamin C and cancer•Vitamin C is effective in protecting tissuesagainst oxidative damage. It suppresses theformation of carcinogens. Numerous studieshave reported the protective effect of fruit andvegetable consumption on incidence ofcancer . This is mainly attributed to theprotective effect of vitamin C against cancer.
    13. 13. Vitamin C and cardiovascular disease•Vitamin C may lower total cholesterol inthe blood, thus reducing the risk ofcardiovascular disease. Coronary heartdisease mortality is higher in those withblood vitamin C levels that are near or inthe deficient range.
    14. 14. Vitamin C and cataracts•High intake of fruits and vegetableswhich are rich sources of ascorbic acidappear to be protective too. In severalstudies, cataract patients were shown tohave low vitamin C and E intakes andlow plasma vitamin C levels.
    15. 15. Carotenoids•Carotenoids are a group of red, orangeand yellow pigments found in plantfoods, particularly fruits and vegetables.• Some carotenoids like b-carotene actas a precursor of vitamin A; others donot.
    16. 16. Superoxide Dismutase (SOD) is essential for the body and is: A metalloprotein – containing several sub units organised around a metallic group And most importantly An enzyme – the antioxidant enzyme SOD eliminates, in a continuous way, superoxideradicals, precursors of other oxygen reactive forms (secondary free radicals)
    17. 17. SOD acts at the source. It is the first and one of themajor components of the body’s antioxidant system.SOD is a powerful and efficient antioxidant: • 1 iu SOD eliminates 1μmol superoxide/min and SOD has an active lifespan of several days! • In the end, billions of superoxide molecules destroyed SOD is a primary antioxidant and possibly our most important one
    18. 18. Reactive oxygen species: formation of secondary free radicalsHydroxyl radical induces the formation ofsecondary free radicals: • Secondary free radicals or organic peroxides are very toxic • They increase oxidative reactions which are propagated from one to the next • They are directly responsible for cell alterations and destruction • They indirectly participate in the inflammation process
    19. 19. Pro-Oxidants Antioxidants(Reactive Oxygen SpeciesFree Radicals) OXIDATIVE STRESS Cell & Tissue Damage Oxidants AntioxidantsCell / Tissue Damage Protection / Tissue Repair
    20. 20. Antioxidant systems: the primary antioxidantsThe primary antioxidants: • are endogenous molecules • act at the source (where free radicals are created) • are enzymes which continuously eliminate the free radicals just formed: - SOD eliminates the superoxide ion - catalase and the glutathione peroxidase eliminate hydrogen peroxide
    21. 21. Antioxidant systems: the secondary antioxidantsThe secondary antioxidants • are exogenous molecules, carried by food (vitamins A, C, E, polyphenols…) • they scavenge the secondary free radicals • one molecule of a secondary antioxidant traps one free radical molecule – a 1:1 relationship
    22. 22. Oxidants and antioxidants in the bodyUnder normal circumstances andconditions, the body’s endogenousantioxidant systems are able to neutralizethe oxidant (free radical) molecules Therefore → no oxidative stress means → no cell damage
    23. 23. Oxidative stress… …is the result of an imbalance between oxidant and antioxidant production increase of free radicals→ antioxidant systems overpowered
    24. 24. Oxidative stress: consequencesA break in the equilibrium caused by… • UVA and B • Stress, overwork, diet • Pollution, chemicals, cigarettes • Chronic inflammation … puts the body into oxidative stress: → attacks on cell constituents (cell membranes, protein, lipids DNA) Only solution: we must combat free radicals
    25. 25.  Lipid L• O2 (LH) OH• H2O  Fe 2+  LOO• H2O2 1 O2  UV light   heme Fe H2O, H+ CoQ H + O2 O2-• HOO•   NADPH H+ or CoQ Figure 5. Pathways for the formation of reactive oxygen species  Singlet oxygen  lipid radical  Peroxyl radical  Haber-Weiss Superoxide reaction;  lipid peroxyl radical anion  Superoxide  Fenton reaction radical dismutase
    26. 26. The fight against secondary free radicals……occurs with the secondary antioxidants (vitamins A,C, E, polyphenols etc) BUT antioxidants (acting 1 against 1) are quickly outnumbered and cannot eliminate a continuous and strong production of free radicals
    27. 27. Secondary antioxidants are vital but just slow down the oxidative stress– we need to do something extra…
    28. 28. Functions of Pentose Phosphate Pathway 1) NADPH for biosynthetic pathways (e.g., synthesis of fatty acids and cholesterol); 2) NADPH for maintaining glutathione in its reduced state . 3) Pentose sugar for synthesis of nucleic acids
    29. 29. Table 1. Reactive Oxygen Species and Antioxidants that Reduce ThemReactive Species AntioxidantSinglet oxygen 1O2 Vitamin A, vitamin ESuperoxide radical (O2-•) superoxide dismutase, vitamin CHydrogen peroxide(H2O2) Catalase; glutathione peroxidasePeroxyl radical (ROO•) Vitamin C, vitamin ELipid peroxyl radical Vitamin E(LOO•)Hydroxyl radical (OH•) Vitamin C
    30. 30. H2O2 glutathione 2 H2O peroxidase GSSG 2 glutathione GSH reductase NADP+ NADPH + H+ pentose pathwayFigure 6. Reactions of glutathione reduction and oxidation
    31. 31. SUMMARY OF ANTI-OXIDANT ENZYMESGlutathione peroxidase: 2 GSH + H2O2  GSSG + 2 H2OUses selenium as a cofactorCatalase : 2 H2O2  H2O + O2Lipid Peroxidase: removes LOOHSuperoxide dismutase: 2 O2-• + 2H+ → H2O2 + O2Mitochondrial - Mn2+ cofactorCytoplasmic – Cu2+-Zn2+ cofactors; mutationsassociated with familial amyotrophic lateral sclerosis(FALS)
    32. 32. NUTRITIONAL CORRELATE: SELENIUM selenocysteine in glutathione peroxidase intake may be related to lower cancer mortality • cancer patients have lower plasma Se levels • risk may be higher in those with low Se intake • AZCC study – reduced incidence of prostate, colon, lung cancers toxicity (> 1 mg/day) results in hair loss, GI upset,nerve damage
    33. 33. lipid peroxyl radical Figure 7. Antioxidant cascade LOO• rxn 5 LOOH Reduced forms/reduction Oxidized forms/oxidation Vit Ered VIT Eox rxn 6 hydroxyl radical (OH•) superoxide radical (O2-•) rxn 9 VIT Cox Vit Cred rxn 7 reduced rxn 4 products H2O2 +ROOH Glutathioneox Glutathionered rxn 2 (GSSG) 2H2O (GSH) NADP+ rxn 1 NADPH + H+ Pentose phosphate pathway (rxn 8) Glucose-6-P Ribulose-5-P
    34. 34. Medical Scenario:If the antioxidant protective system in the redblood cell becomes defective, hemolyticanemia occurs; that is red blood cells undergohemolysis and their concentration in the blooddecreases. Such is the case if g luc o s e 6 -p ho s p ha te d e hy d ro g e na s e is defective in thepentose phosphate pathway. In individualswhose glucose 6-phosphate dehydrogenase isdefective, there is insufficient NADPH producedin red blood cells to maintain the ratio ofreduced glutathione to oxidized glutathione atits normal value of well over 100. Hence,
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