title: Effect of black tea on (iso-)prostaglandins and platelet aggregation in healthy volunteers.
abstract: Flavonoids among others are found in tea. Many of them were shown to exhibit antioxidative action in vitro. We examined the effect of a 1-month consumption of 500 ml black tea containing 2.0 mg quercetin. While single tea consumption 2 h after finishing the intake did not affect any of the parameters (8-epi-PGF(2 alpha) in plasma and serum, 11-DH-TXB(2) and ADP-induced platelet aggregation) examined at all, 1-week consumption and even more than 1 month regular tea intake significantly decreased most of the parameters. The effect was somewhat more pronounced for females as compared with males, the values for 11-dehydro-thromboxane B(2) (11-DH-TXB(2)) and ADP-induced aggregation reached the level of significance in females only. These data show that regular daily black tea consumption for 1 month improves platelet function and decreases thromboxane and 8-epi-PGF(2 alpha) to a varying extent indicating a reduced in vivo oxidation injury.
authors.affiliation: Department of Angiology, University of Vienna, Austria.
authors.forename: R M
authors.initials: RM
authors.lastname: Wolfram
authors.forename: A
authors.initials: A
authors.lastname: Oguogho
authors.forename: Y
authors.initials: Y
authors.lastname: Efthimiou
authors.forename: A C
authors.initials: AC
authors.lastname: Budinsky
authors.forename: H
authors.initials: H
authors.lastname: Sinzinger
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D016001:Confidence Intervals; D015237:Dinoprost / Q000031:analogs & derivatives*; D028441:F2-Isoprostanes / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects*; D011794:Quercetin / Q000494:pharmacology; D012737:Sex Factors; D013662:Tea; D013929:Thromboxane B2 / Q000097:blood*; D013997:Time Factors
chemical_list: D028441:F2-Isoprostanes; D013662:Tea; C075750:8-epi-prostaglandin F2alpha; D013929:Thromboxane B2; D000244:Adenosine Diphosphate; D011794:Quercetin; D015237:Dinoprost