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ARS Home » Southeast Area » Little Rock, Arkansas » Microbiome and Metabolism Research Unit » Research » Publications at this Location » Publication #151343
Title: PLASMA LIPOPHILIC AND HYDROPHILIC ANTIOXIDANT STATUS IN HUMAN SUBJECTS: EFFECTS OF MEALS CONTAINING DIFFERENT BERRIES OR FRUITS

Author
item Prior, Ronald
item WU, XIANLI - UAMS
item HOANG, HA - ACNC
item JACOBS, ROBERT - USDA/WHNC

Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 1/10/2003
Publication Date: 3/17/2003
Citation: PRIOR, R.L., WU, X., HOANG, H., JACOBS, R. Plasma Lipophilic and Hydrophilic Antioxidant Status in Human Subjects: Effects of meals containing different berries or fruits. JOURNAL OF FEDERATION OF AMERICAN SOCIETIES FOR EXPERIMENTAL BIOLOGY. 2003. v. 17(5). p. A1114. Abstract No. 694.8.

Interpretive Summary: The ACNC is interested in studying the health benefits of dietary factors the are not considered to be the traditional nutrients such as vitamins, minerals, etc.). These factors are typically compounds (called phytochemicals) bound to proteins in vegetables, grains and fruits. A class of these phytochemicals are known as anti-oxidants and it is thought that they convey health benefits by reducing the damaging effects of a process known as oxidation. We have developed methods to assess the anti-oxidant capacity (called the Oxygen Radical Absorbing Capacity (ORACFL) of blood after consumption of food as an estimate of the anti-oxidant capacity in various foods. These methods, for the first time, provide the ability to obtain a measure of 'Total Antioxidant Capacity' in plasma and foods. We found that lipid soluble antioxidants are low in most fruits and berries (0.4-3% of total antioxidant capacity). Following consumption of 289 g of sweet cherries, a significant increase in lipid soluble antioxidants occurred at 3 and 5 h after the meal, while slight decreases were observed in water soluble antioxidants at 3 h post-meal. Consumption of a meal containing grapes (280 g), kiwi (300 g), or strawberries (300 g) resulted in no changes in plasma lipid soluble antioxidants but small increases in water soluble anti-oxidants were observed; a blueberry (189 g) meal resulted in increases in both water and lipid soluble anti-oxidants following the meal. These results will be used in future experiments to determine the biological effects in organs and to assess their health benefits. This will lead identification of specific anti-oxidants and their mechanisms of actions, and eventually to predicting what foods provide the most protection and how much of this food needs to be consumed and how often to provide health benefits.

Technical Abstract: Methods of analysis of hydrophilic (H-) and lipophilic (L-) antioxidant (AO) capacity using modifications of the Oxygen Radical Absorbing Capacity (ORAC (FL)) procedure were developed. Plasma was extracted with hexane after adding water and ethanol (Hexane:Plasma:Ethanol:Water; 4:1:2:1; v/v); the hexane fraction was dried under N2, dissolved in acetone, diluted in 50% aqueous acetone containing 7% randomly methylated ß-cyclodextrin and analyzed for L-ORAC(FL). The aqueous fraction was treated with 0.5 N perchloric acid (1:4 v/v) to precipitate protein and the supernatant was analyzed for H-ORAC(FL). L-ORAC (FL) represented 30-40% of the total AO capacity (L-ORAC(FL) + H-ORAC(FL)) of protein free plasma. L-ORAC(FL) capacity is low in most fruits and berries (0.4-3% of total ORAC FL), however, following consumption of 289 g of sweet cherries, a significant increase in L-ORAC(FL) occurred at 3 and 5 h after the meal; H-ORAC(FL) decreased slightly at 3 h post-meal. Consumption of a meal containing grapes (280 g), kiwi (300 g), or strawberries (300 g) resulted in no changes in plasma L-ORAC(FL) but small increases in H-ORAC(FL) were observed; a blueberry (189 g) meal resulted in increases in both H- and L-ORAC(FL) following the meal. These methods, for the first time, provide the ability to obtain a measure of 'Total AO Capacity' in the protein free plasma using the same peroxyl radical generator for both L- and H-ORAC(FL).