title: 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.
abstract: 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.
authors.affiliation: Department of General Physiology, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Prymont-Przyminska
authors.affiliation: Cell-to-cell Communication Department, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Zwolinska
authors.affiliation: Department of General Physiology, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Sarniak
authors.affiliation: Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Wlodarczyk
authors.affiliation: Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Krol
authors.affiliation: Medical Physics Faculty, University of Lodz, Lodz, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Nowak
authors.affiliation: Thoracic Innovation, Fort Lauderdale, Florida, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: de Graft-Johnson
authors.affiliation: Academic Laboratory of Movement and Human Physical Performance, Medical University of Lodz, Lodz, Poland.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Padula
authors.affiliation: Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Bialasiewicz
authors.affiliation: Research Institute of Horticulture, Division of Pomology, Fruit Storage and Processing Department, Skierniewice, Poland.
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Markowski
authors.affiliation: Research Institute of Horticulture, Division of Pomology, Fruit Storage and Processing Department, Skierniewice, Poland.
authors.forename: Krzysztof P
authors.initials: KP
authors.lastname: Rutkowski
authors.affiliation: Department of Clinical Physiology, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Nowak
keywords: dietary intervention; plasma antioxidant activity; polyphenols; strawberry