title: A mechanism of the thearubigin fraction of black tea (Camellia sinensis) extract protecting against the effect of tetanus toxin.
abstract: The aim of the present study was to elucidate the mechanism of the protective effect of black tea extract's thearubigin fraction against the action of tetanus toxin. The effects of thearubigin fraction extracted from a black tea infusion were examined for neuromuscular blocking action on tetanus toxin in mouse phrenic nerve-diaphragm preparations and on the binding of this toxin to the synaptosomal membrane preparations of rat cerebral cortices. The interaction between tetanus toxin and thearubigin fraction was also investigated. Tetanus toxin (4 micrograms/ml) abolished indirect twitches in mouse phrenic nerve-diaphragm preparations within 150 min. Thearubigin fraction mixed with tetanus toxin blocked the inhibitory effect of the toxin. Mixing iodinated toxin with thearubigin fraction inhibited the specific binding of [125I]tetanus toxin to the synaptosomal membrane preparation. The effects of thearubigin fraction were dose-dependent. The elution profile of [125I]tetanus toxin on Sephadex G-50 column chromatography was different from that of toxin mixed with thearubigin fraction. These findings indicate that thearubigin fraction protects against the action of tetanus toxin by binding with the toxin.
authors.affiliation: Department of Pathobiological Science, Obihiro University of Agriculture and Veterinary Medicine, 11, West-2, Inada, Obihiro 080-8555, Japan.
authors.forename: Eiki
authors.initials: E
authors.lastname: Satoh
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ishii
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Sawamura
authors.forename: Masakazu
authors.initials: M
authors.lastname: Nishimura
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D003964:Diaphragm / Q000187:drug effects; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology; D010243:Paralysis / Q000139:chemically induced / Q000517:prevention & control; D010636:Phenols / Q000494:pharmacology*; D010791:Phrenic Nerve / Q000187:drug effects; D059808:Polyphenols; D013574:Synaptosomes / Q000187:drug effects; D013662:Tea / Q000737:chemistry*; D013744:Tetanus Toxin / Q000037:antagonists & inhibitors* / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D009466:Neuromuscular Blocking Agents; D010636:Phenols; D059808:Polyphenols; D013662:Tea; D013744:Tetanus Toxin; C086701:thearubigin; D002392:Catechin