Improvement of Endothelial Function by EGCG
Cardiovascular diseases are a major cause of morbidity and mortality worldwide. Impaired endothelial function (assessed as flow-mediated dilation) represents an early marker for later cardiovascular events. Epidemiological and experimental studies suggest that consumption of tea is associated with lower progression of atherosclerosis and reduced cardiovascular mortality.
Tea contains high amounts of polyphenols with important biological activities. The green tea catechin epigallocatechin-3-gallate (EGCG) is the most potent physiologically active compound in vitro. However, little is known about its contribution to beneficial effects of tea in vivo.
In this crossover study the impact of a single dose of EGCG applied in different forms (green tea beverage, green tea extract and EGCG) on flow-mediated dilation is investigated in healthy volunteers two hours after ingestion. The amount of EGCG (200 mg) corresponds to appr. 0.5 L of green tea. The results of the study will elucidate the contribution of EGCG in cardiovascular protective effects of green tea in vivo. The outcomes will provide insights about the role of EGCG in different application forms to improvements of endothelial function in humans.
|Cardiovascular Diseases||Dietary Supplement: Green tea beverage Dietary Supplement: Green tea extract Dietary Supplement: EGCG Other: Placebo|
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
|Official Title:||The Role of EGCG in Different Application Forms on Flow-mediated Dilation in Healthy Volunteers|
- Flow-mediated dilation of the arteria brachialis [ Time Frame: 2 hours after ingestion ]Change in flow-mediated dilation (in %) of the arteria brachialis after a single dose of 200 mg EGCG either as green tea beverage, green tea extract or EGCG is assessed by vascular ultrasound.
- Agonist-induced platelet aggregation in vitro [ Time Frame: 2 hours after ingestion ]Blood is drawn two hours after consumption and the effects on in vitro agonist-induced platelet aggregation after a single dose of 200 mg EGCG either as green tea beverage, green tea extract or EGCG are measured.
- Determination of plasma tea polyphenol levels [ Time Frame: 2 hours after ingestion ]Blood is drawn two hours after consumption and plasma concentrations of tea polyphenols are measured after a single dose of 200 mg EGCG either as green tea beverage, green tea extract or EGCG by HPLC.
|Study Start Date:||August 2012|
|Study Completion Date:||September 2013|
|Primary Completion Date:||September 2013 (Final data collection date for primary outcome measure)|
Active Comparator: Green tea beverage
200 mg EGCG as green tea beverage.
|Dietary Supplement: Green tea beverage|
Active Comparator: Green tea extract
200 mg EGCG as green tea extract and same volume water as for tea beverage.
|Dietary Supplement: Green tea extract|
Active Comparator: Epigallocatechin-3-gallate (EGCG)
200 mg EGCG and same volume water as for tea beverage.
|Dietary Supplement: EGCG|
Placebo Comparator: Placebo (Water)
Same volume water as for all intervention arms.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01662232
|Department of Cardiology and Angiology, Campus Mitte, Charité University Medicine Berlin|
|Berlin, Germany, 10117|
|Principal Investigator:||Mario Lorenz, PhD||Department of Cardiology and Angiology, Campus Mitte, Charité University Medicine Berlin, Germany|