Consumption of strawberries on a daily basis increases the non-urate 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity of fasting plasma in healthy subjects

• Published in: Journal of Clinical Biochemistry and Nutrition Vol. 55; no. 1; pp. 48 - 55
• Main Authors: Prymont-Przyminska, Anna, Zwolinska, Anna, Sarniak, Agata, Wlodarczyk, Anna, Krol, Maciej, Nowak, Michal, Graft-Johnson, Jeffrey de, Padula, Gianluca, Bialasiewicz, Piotr, Markowski, Jaroslaw, Rutkowski, Krzysztof P., Nowak, Dariusz
• Format: Journal Article
• Language: English
• Published: Japan SOCIETY FOR FREE RADICAL RESEARCH JAPAN 2014; Japan Science and Technology Agency; the Society for Free Radical Research Japan
• Subjects: Antioxidants; Body weight; Decomposition; dietary intervention; Fruits; Liquid chromatography; Original; Oxidizing agents; Phenols; plasma antioxidant activity; polyphenols; Risk reduction; strawberry; strawberry; polyphenols; plasma antioxidant activity; dietary intervention
• ISSN: 0912-0009; 1880-5086
• DOI: 10.3164/jcbn.13-93

Strawberries contain anthocyanins and ellagitanins which have antioxidant properties. We determined whether the consumption of strawberries increase the plasma antioxidant activity measured as the ability to decompose 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) in healthy subjects. The study involved 10 volunteers (age 41 ± 6 years, body weight 74.4 ± 12.7 kg) that consumed 500 g of strawberries daily for 9 days and 7 matched controls. Fasting plasma and spot morning urine samples were collected at baseline, during fruit consumption and after a 6 day wash-out period. DPPH decomposition was measured in both deproteinized native plasma specimens and pretreated with uricase (non-urate plasma). Twelve phenolics were determined with HPLC. Strawberries had no effect on the antioxidant activity of native plasma and circulating phenolics. Non-urate plasma DPPH decomposition increased from 5.7 ± 0.6% to 6.6 ± 0.6%, 6.5 ± 1.0% and 6.3 ± 1.4% after 3, 6 and 9 days of supplementation, respectively. The wash-out period reversed this activity back to 5.7 ± 0.8% (p<0.01). Control subjects did not reveal any changes of plasma antioxidant activity. Significant increase in urinary urolithin A and 4-hydroxyhippuric (by 8.7- and 5.9-times after 6 days of supplementation with fruits) was noted. Strawberry consumption can increase the non-urate plasma antioxidant activity which, in turn, may decrease the risk of systemic oxidants overactivity.