title: Pharmacokinetics of (-)-epigallocatechin-3-gallate in conscious and freely moving rats and its brain regional distribution.
abstract: A liquid chromatography technique coupled with tandem mass spectrometry (LC-MS/MS) electrospray ionization was used to measure (-)-epigallocatechin-3-gallate (EGCG) in rat plasma. This method was applied to investigate the pharmacokinetics of EGCG in a conscious and freely moving rat by an automated blood sampling device. Multiple reaction monitoring (MRM) was used to monitor the transition of the deprotonated molecule m/z of 457 [M - H]- to the product ion 169 for EGCG and the m/z of 187 to 164 for the internal standard. The limit of quantification (LOQ) of EGCG in rat plasma was determined to be 5 ng/mL, and the linear range was 5-5000 ng/mL. The protein binding of EGCG in rat plasma was 92.4 +/- 2.5%. The brain distribution result indicated that EGCG may potentially penetrate through the blood-brain barrier at a lower rate. The disposition of EGCG in the rat blood was fitted well by the two-compartmental model after intravenous administration (10 mg/kg, iv). The elimination half-life of EGCG was 62 +/- 11 and 48 +/- 13 min for intravenous (10 mg/kg) and oral (100 mg/kg) administration, respectively. The pharmacokinetic data indicate that the oral bioavailability of EGCG in a conscious and freely moving rat was about 4.95%.
authors.affiliation: Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, 155 Li-Nong Street Section 2, Taipei 112, Taiwan.
authors.forename: Lei-Chwen
authors.initials: LC
authors.lastname: Lin
authors.forename: Meng-Nan
authors.initials: MN
authors.lastname: Wang
authors.forename: Ting-Yu
authors.initials: TY
authors.lastname: Tseng
authors.forename: Jung-Sung
authors.initials: JS
authors.lastname: Sung
authors.forename: Tung-Hu
authors.initials: TH
authors.lastname: Tsai
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D001923:Brain Chemistry; D028241:Camellia sinensis / Q000737:chemistry; D002392:Catechin / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
chemical_list: D001798:Blood Proteins; D002392:Catechin; C045651:epigallocatechin gallate