Oral absorption and bioavailability of tea catechins

Planta Med. 2000 Jun;66(5):444-7. doi: 10.1055/s-2000-8599.


The absorption characteristics and oral bioavailability of three tea catechins, namely (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG), were assessed in this study. Male Sprague Dawley rats (210-230 g) received either an intravenous (i.v. 50 mg/kg) or oral (5000 mg/kg) dose of decaffeinated catechin-fraction containing EC (5%), EGCG (50%), and ECG (13%). Concentrations of the compounds in plasma, urine, and feces were measured using HPLC. A non-compartmental approach was employed for pharmacokinetic analysis. Results indicated that maximum plasma concentrations for the catechins (15-112 micrograms/ml) were achieved at 2 h post-oral dosing and the apparent volume of distribution (Vd/F) ranged from 30 to 63 l/kg. Absolute bioavailability (F) of EC, EGCG, and ECG was assessed to be 0.39, 0.14, and 0.06, respectively. Estimates of terminal elimination half-life (t1/2, lambda z) of the catechins after oral dosing were 451-479 min and were 1.4-10 fold longer than those observed for the i.v. dosing. The discrepancy in terminal elimination and low rate and extent of absorption indicated the possibility of flip-flop kinetics. Respective urinary recoveries were 0.17-4.72% and 2.11-14.2% after oral and i.v. dosing. In conclusion, the low systemic availability of tea catechins observed could be a result of slow absorption, high first pass effect, and wide tissue distribution.

MeSH terms

  • Absorption
  • Administration, Oral
  • Animals
  • Biological Availability
  • Catechin / analogs & derivatives*
  • Catechin / pharmacokinetics*
  • Catechin / urine
  • Chromatography, High Pressure Liquid
  • Injections, Intravenous
  • Male
  • Mouth Mucosa / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Tea / chemistry*


  • Tea
  • Catechin
  • epicatechin gallate
  • epigallocatechin gallate