title: Do flavan-3-ols from green tea reach the human brain?
abstract: Following acute ingestion of green tea by six human subjects, HPLC-MS2 analysis revealed that flavan-3-ol methyl, glucuronide and sulfate metabolites appeared in the bloodstream but did not pass through the blood-cerebrospinal fluid barrier. These observations emphasize the discrepancies between in vitro and in vivo evidence on the neuroprotective role of these compounds. If, as has been proposed, green tea exerts neuroprotective effects, this finding indicates that the active components are not flavan-3-ols or their metabolites. Alternatively, a systemic action may be hypothesised whereby dietary flavan-3-ols up-regulate antioxidant defences and/or reduce inflammation, the benefit of which may be effective throughout the body.
authors.affiliation: Department of Neuroscience, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Zini
authors.forename: Daniele
authors.initials: D
authors.lastname: Del Rio
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Stewart
authors.forename: Jessica
authors.initials: J
authors.lastname: Mandrioli
authors.forename: Elisa
authors.initials: E
authors.lastname: Merelli
authors.forename: Patrizia
authors.initials: P
authors.lastname: Sola
authors.forename: Paolo
authors.initials: P
authors.lastname: Nichelli
authors.forename: Mauro
authors.initials: M
authors.lastname: Serafini
authors.forename: Furio
authors.initials: F
authors.lastname: Brighenti
authors.forename: Christine A
authors.initials: CA
authors.lastname: Edwards
authors.forename: Alan
authors.initials: A
authors.lastname: Crozier
mesh_terms: D000328:Adult; D001812:Blood-Brain Barrier; D001921:Brain / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005419:Flavonoids / Q000097:blood / Q000134:cerebrospinal fluid / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D013662:Tea / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D013662:Tea; C404987:flavan-3-ol