Journal of the American College of Nutrition, Vol. 17, No. 5, 468-469 (1998)
Published by the American College of Nutrition
Models of Antioxidant Protection Against Biological Oxidative Damage
Al Tappel, PhD
Professor Emeritus
University of California
Davis, CA
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INTRODUCTION
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There are many published works describing antioxidant protection against oxidation. Most do not present enough data to construct a model or simulation model that delineates the effects of components of the reaction to the overall result of the oxidation or inhibition process. In Bowen and Omaye [1] enough data are given to construct a simple simulation model. The advantages of modeling biological oxidations have been previously described [2,3]. Briefly, a model puts into perspective the experimental results so that the dynamics of the reaction can be visualized. A simple simulation model describing the reaction is:
The model is related to the basic relationship:
Products of Peroxidation=Oxidized Lipid and Enhancers of Oxidation/Antioxidants. (1/LAG) is the reciprocal of the time before the propagation phase of peroxidation. RATE is the maximum change in TBARS during the propagation phase of oxidation. (1/LAG)+RATE are a good expression of the oxidation and are calculated and compared to the experimental equivalents from Table 1 of Bowen and Omaye [1]. OXxLDL is a constant that represents all of the oxidation in LDL not otherwise expressed. CAROTENE is the concentration of ß-carotene given in Table 1 [1]. TOCOPHEROL is the concentration of 
-tocopherol given in Table 1 [1]. When values of (1/LAG)+RATE are calculated using the concentrations of ß-carotene and -tocopherol in Table 1 [1] and compared to the experimental values of (1/lag)+rate of Table 1, good agreement is found. Application of regression analysis of the calculated values of (1/LAG)+RATE and the experimental values of (1/lag)+rate of Table 1[1] gives r=0.77, p=0.001. This example of the application of—simulation modeling shows that—it could be a valuable addition to many studies.
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REFERENCES
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- Bowen HT, Omaye ST: Oxidative changes associated with ß-carotene and -tocopherol enrichment of human low-density lipoproteins.
J Am Coll Nutr
17(2):
171–179,
1998.[Abstract/Free Full Text]
- Tappel AL, Tappel AA, Fraga CG: Application of simulation modeling to lipid peroxidation processes.
Free Radical Biol Med
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361–368,
1989.[Medline]
- Tappel AL: Combinations of vitamin E and other antioxygenic nutrients in protection of tissues. In Packer L, Fuchs J (eds): "Vitamin E in Health and Disease," New York: Marcel Dekker, Inc.,
313–325,
1992.
Stanley T. Omaye, PhD, FACN, CNS
Department of Nutrition
University of Nevada
Reno, NV
Author’s Reply
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Simulation Modeling as an Adjunct to Data Evaluation of Oxidative Damage
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We appreciate the comments of Professor Al L. Tappel regarding our recently published study [1]. We are also grateful to him for taking the time to fit our data to his simulation model. I agree with his premise that the use of such modeling can put the experimental results into a visual perspective; thus, providing valuable supportive information for a study. Simulation models can be a valuable adjunct for interpretation of results from oxidative damage and antioxidant studies. This is particularly appropriate because of the challenges often provided in the quantitation of the effects of multiple antioxidants in isolated low density lipoprotein (LDL) suspensions. I would like to highlight that the calculated model values were in good agreement with our experimental values, providing further credence for our conclusions. Thus, the findings from the modeling are gratifying to these researchers.
Because of our ongoing interest to elucidate the nature of effects produced by the enrichment of such LDL with combinations of antioxidants on human LDL oxidation, we hope to make use of similar simulation modeling in future work. Furthermore, we believe that the use of such modeling can complement the evaluation of data from many multi parameter studies.
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REFERENCE
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- Bowen HT, Omaye ST: Oxidative changes associated with ß-carotene and -tocopherol enrichment of human low density lipoproteins.
J Am Coll Nutr
17:
171–179,
1998.
TOP
INTRODUCTION
REFERENCES
