title: Liquid chromatography tandem mass spectrometry identification of proanthocyanidins in rat plasma after oral administration of grape seed extract.
abstract: Proanthocyanidin rich plant extracts derived from grape seed extract (GSE), hawthorn and cranberry are on markets for their preventive effects against cardiovascular diseases and uroinfections in woman. However, the importance of these health beneficial effects of these botanicals remains elusive due to incomplete understanding of uptake, metabolism and bioavailability of proanthocyanidins in vivo. In the present study rats were given GSE orally (300 mg/kg, twice a day) and blood and urine were collected over a 24 h period. Monomeric catechins and their methylated metabolites, and proanthocyanidins up to trimers were detected in blood samples treated with GSE using LC-MS/MS operating in the multiple reaction monitoring (MRM) mode. A new tetramethylated metabolite of dimeric proanthocyanidin (m/z 633) in GSE-treated urine was tentatively identified. Using LC-MS/MS, (+)-catechin and (-)-epicatechin were identified in the brain conclusively. These data suggested that GSE catechins cross the blood brain barrier and may be responsible for the neuroprotective effects of GSE.
authors.affiliation: Department of Pharmacology, University of Alabama at Birmingham, Birmingham, AL 35294, USA. jprasain@uab.edu
authors.forename: Jeevan K
authors.initials: JK
authors.lastname: Prasain
authors.forename: Ning
authors.initials: N
authors.lastname: Peng
authors.forename: Yanying
authors.initials: Y
authors.lastname: Dai
authors.forename: Ray
authors.initials: R
authors.lastname: Moore
authors.forename: Alireza
authors.initials: A
authors.lastname: Arabshahi
authors.forename: Landon
authors.initials: L
authors.lastname: Wilson
authors.forename: Stephen
authors.initials: S
authors.lastname: Barnes
authors.forename: J
authors.initials: J
authors.lastname: Michael Wyss
authors.forename: Helen
authors.initials: H
authors.lastname: Kim
authors.forename: Ray L
authors.initials: RL
authors.lastname: Watts
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001921:Brain / Q000378:metabolism; D002392:Catechin / Q000378:metabolism*; D002853:Chromatography, Liquid / Q000379:methods; D005419:Flavonoids / Q000378:metabolism; D056604:Grape Seed Extract; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D044945:Proanthocyanidins / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012639:Seeds; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D027843:Vitis / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D056604:Grape Seed Extract; C511402:Grape Seed Proanthocyanidins; D010936:Plant Extracts; D044945:Proanthocyanidins; C404987:flavan-3-ol; D002392:Catechin