Universität zu Köln

Lorenz, Mario ORCID: 0000-0001-5267-4101, Lehmann, Stephanie, Djordjevic, Ilija, Duesterhoeft, Thomas, Zimmermann, Benno F., Stangl, Karl and Stangl, Verena (2020). Vasodilation of Tea Polyphenols Ex Vivo Is Mediated by Hydrogen Peroxide under Rapid Compound Decay. Antioxidants, 9 (5). BASEL: MDPI. ISSN 2076-3921

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Abstract

Improvement of endothelial function represents a major health effect of tea in humans. Ex vivo, tea and tea polyphenols stimulate nitric oxide (NO)-dependent vasodilation in isolated blood vessels. However, it was reported that polyphenols can generate reactive oxygen species (ROS) in vitro. We therefore aimed to elucidate the role of ROS production in tea polyphenol-induced vasodilation in explanted aortic rings. Vasorelaxation of rat aortic rings was assessed in an organ chamber model with low concentrations of epigallocatechin-3-gallate (EGCG), theaflavin-3,3'-digallate (TF3), and with green and black tea, with or without pretreatment with catalase or superoxide dismutase (SOD). The stability of EGCG and TF3 was measured by HPLC, and the levels of hydrogen peroxide (H2O2) were determined. EGCG and green tea-induced vasorelaxation was completely prevented by catalase and slightly increased by SOD. TF3 and black tea yielded similar results. Both EGCG and TF3 were rapidly degraded. This was associated with increasing H2O2 levels over time. Hydrogen peroxide concentrations produced in a time range compatible with tea polyphenol decay induced NO-dependent vasodilation in aortic rings. In conclusion, tea polyphenol-induced vasodilation in vitro is mediated by low levels of H2O2 generated during compound decay. The results could explain the apparent lack of vasodilatory effects of isolated tea polyphenols in humans.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Lorenz, Mario UNSPECIFIED orcid.org/0000-0001-5267-4101 UNSPECIFIED Lehmann, Stephanie UNSPECIFIED UNSPECIFIED UNSPECIFIED Djordjevic, Ilija UNSPECIFIED UNSPECIFIED UNSPECIFIED Duesterhoeft, Thomas UNSPECIFIED UNSPECIFIED UNSPECIFIED Zimmermann, Benno F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Stangl, Karl UNSPECIFIED UNSPECIFIED UNSPECIFIED Stangl, Verena UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-334981
DOI:	10.3390/antiox9050390
Journal or Publication Title:	Antioxidants
Volume:	9
Number:	5
Date:	2020
Publisher:	MDPI
Place of Publication:	BASEL
ISSN:	2076-3921
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language NITRIC-OXIDE SYNTHASE; GREEN TEA; BLACK TEA; CARDIOVASCULAR-DISEASE; NO PRODUCTION; CONSUMPTION; STABILITY; (-)-EPIGALLOCATECHIN-3-GALLATE; ATHEROSCLEROSIS; MORTALITY Multiple languages Biochemistry & Molecular Biology; Chemistry, Medicinal; Food Science & Technology Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/33498