Improvement of Endothelial Function by EGCG

Not Applicable

Completed

• Conditions: Cardiovascular Diseases
• Interventions: Dietary Supplement: EGCG; Dietary Supplement: Green tea extract; Other: Placebo; Dietary Supplement: Green tea beverage

• Registration Number: NCT01662232
• Lead Sponsor: Charite University, Berlin, Germany

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2012-08
• Study First Submitted: 2012-08-07
• Study First Submitted QC: 2012-08-09
• Study First Posted: 2012-08-10
• Primary Completion: 2013-09
• Study Completion: 2013-09
• Status Verified: 2016-02
• Last Update Submitted: 2016-02-02
• Last Update Posted: 2016-02-03

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 50

Inclusion Criteria

• Male healthy volunteers
• 20-50 years
• BMI < 27 kg/m2
• Cholesterol < 240 mg/dl

Exclusion Criteria

• Diabetes mellitus
• Hypertension
• Conditions with impaired endothelial function
• Smoking
• Regular drug use
• Alcohol abuse
• Regular tea drinkers

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Epigallocatechin-3-gallate (EGCG)	EGCG	200 mg EGCG and same volume water as for tea beverage.
Green tea extract	Green tea extract	200 mg EGCG as green tea extract and same volume water as for tea beverage.
Placebo (Water)	Placebo	Same volume water as for all intervention arms.
Green tea beverage	Green tea beverage	200 mg EGCG as green tea beverage.

Primary Outcome Measures

Name	Time	Method
Flow-mediated dilation of the arteria brachialis	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.

Secondary Outcome Measures

Name	Time	Method
Agonist-induced platelet aggregation in vitro	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	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.

Trial Locations

Locations (1)

Department of Cardiology and Angiology, Campus Mitte, Charité University Medicine Berlin; 🇩🇪 Berlin, Germany