Biomarkers of antioxidant status following ingestion of green teas at different polyphenol concentrations and antioxidant capacity in human volunteers.
In a randomized cross-over study, 15 healthy volunteers consumed 500 mL of green tea (GTFT) with different solid contents (1.4, 1.6, 1.8 and 2.0 g/L) to induce a dose-response effect on plasma antioxidant capacity. Ingestion of GTFT 2.0 g/L significantly increased plasma reducing power (ferric reducing antioxidant power, FRAP) at 1 h (+2.9%; p<0.01), 2 h (+2.5%; p<0.05) and 4 h (+3.6%; p<0.01). GTFT 1.8 g/L showed statistical significance at 1 h (+4.3%; p<0.01) and 2 h (+4.4%; p<0.01), whereas GTFT 1.6 g/L was effective only at 1 h (+2.9%; p<0.01) and GTFT 1.4 g/L did not induce any changes. The maximum peak of increase in plasma FRAP for different GTFTs was clearly correlated with in vitro FRAP (R=0.778). GTFT 2.0 g/L significantly increased plasma antioxidant potential (total radical-trapping antioxidant parameter) at 1 h (+8.4%; p<0.01), 2 h (+4.4%; p<0.05) and 4 h (+5.9%; p<0.01). The effect of GTFT 1.8 g/L was evident at 1 h (+5.2%; p<0.05) and 2 h (+4.6%; p<0.05) but not at 4 h. No changes in plasma total radical-trapping antioxidant parameter were detected for GTFT at 1.6 and 1.4 g/L. An evidence for a linear correlation between GTFT antioxidant content and the extent of the antioxidant effect in vivo has been provided.
Pecorari
Monia
M
Antioxidant Research Laboratory, Istituto Nazionale di Ricerca per gli Alimenti e la Nutrizione, Rome, Italy.
Villaño
Debora
D
Testa
Maria Francesca
MF
Schmid
Marc
M
Serafini
Mauro
M
D000328:Adult; D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D002934:Cinnamates / Q000008:administration & dosage / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D018592:Cross-Over Studies; D004032:Diet; D057140:Fast Foods / Q000032:analysis; D005260:Female; D005419:Flavonoids / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry; D005527:Food, Fortified / Q000032:analysis; D016166:Free Radical Scavengers / Q000097:blood; D006801:Humans; D008297:Male; D010636:Phenols / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry; D059808:Polyphenols; D021241:Spectrometry, Mass, Electrospray Ionization; D013662:Tea / Q000737:chemistry*; D013997:Time Factors; D055815:Young Adult
D000975:Antioxidants; D015415:Biomarkers; D002934:Cinnamates; D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D059808:Polyphenols; D013662:Tea