Plasma-kinetic characteristics of purified and isolated green tea catechin epigallocatechin gallate (EGCG) after 10 days repeated dosing in healthy volunteers.
This randomized, double-blind, placebo-controlled study assessed the safety, tolerability, and plasma-kinetic behavior of 94% pure crystalline epigallocatechin gallate (EGCG) after ten days' repeated dosing in 36 healthy male volunteers. Each of the three treatment groups consisted of 12 subjects; nine of them received oral EGCG in one dose of 200, 400, or 800 mg daily, and three received a placebo. Blood samples for plasma-kinetic EGCG characterization were taken on day 1 and day 10. Kinetic parameters for rate and extent, elimination half-lives, and accumulation factor (R) were determined and compared between day 1 and day 10 for each dosage group. Orally administered EGCG is rapidly absorbed from the gut. Dose linearity was applied for single-dose application (day 1). After repeated dosing (day 10) dose linearity was applied between the 200 mg and 400 mg group. Dose escalation to 800 mg was more than dose-proportional in rate and extent, and statistically different from the 200 mg and 400 mg group. An increase in elimination half-life (t1/2.z) and in the accumulation factor (R) in the 800 mg dosage group indicates dose-dependent saturation of capacity-limited excretion routes or an increase of hepato-duodenal re-circulation. Ten days' repeated administration of oral doses of EGCG of up to 800 mg per day were found to be safe and very well tolerated.
Ullmann
U
U
Roche Vitamins Ltd, Human Nutrition and Health, Research and Development, Basel, Switzerland. uwe.ullmann@dsm.com
Haller
J
J
Decourt
J D
JD
Girault
J
J
Spitzer
V
V
Weber
P
P
D000293:Adolescent; D000328:Adult; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D004311:Double-Blind Method; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D010919:Placebos; D018515:Plant Leaves / Q000737:chemistry*
D010919:Placebos; D002392:Catechin; C045651:epigallocatechin gallate