title: Additional inhibitory effect of tea extract on the growth of influenza A and B viruses in MDCK cells.
abstract: It has been previously reported that green-tea extract (GTE) inhibits the growth of influenza virus by preventing its adsorption. In this study, we further investigated whether GTE exerts an additional inhibitory effect on the acidification of intracellular compartments such as endosomes and lysosomes (referred to as ELS) and thereby inhibits the growth of influenza A and B viruses in Madin-Darby canine kidney cells. The vital fluorescence microscopic study showed that GTE inhibited acidification of ELS in a concentration-dependent manner. Moreover, the growth of influenza A and B viruses was equally inhibited when the cells were treated with GTE within as early as 5 to 15 min after infection, depending on the virus strains. The fact that (-)epigallocatechin (EGC), one of major catechin molecules in GTE, exerts the inhibitory effects on the acidification of ELS and virus growth in a manner similar to that of GTE strongly suggests that EGC is one of the active components in the extract.
authors.affiliation: Department of Oriental Medicine, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: Nobuko
authors.initials: N
authors.lastname: Imanishi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Tuji
authors.forename: Yuko
authors.initials: Y
authors.lastname: Katada
authors.forename: Miyuki
authors.initials: M
authors.lastname: Maruhashi
authors.forename: Satoko
authors.initials: S
authors.lastname: Konosu
authors.forename: Naoki
authors.initials: N
authors.lastname: Mantani
authors.forename: Katutoshi
authors.initials: K
authors.lastname: Terasawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ochiai
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D011992:Endosomes / Q000187:drug effects; D009980:Influenza A virus / Q000187:drug effects* / Q000254:growth & development; D009981:Influenza B virus / Q000187:drug effects* / Q000254:growth & development; D008247:Lysosomes / Q000187:drug effects; D008856:Microscopy, Fluorescence; D013662:Tea; D013997:Time Factors
chemical_list: D000998:Antiviral Agents; D004365:Drugs, Chinese Herbal; D013662:Tea; D002392:Catechin