title: Elevation of intracellular Zn2+ level by nanomolar concentrations of triclocarban in rat thymocytes.
abstract: It was recently reported that nanomolar concentrations of triclocarban, an antimicrobial agent, were detected in human blood after the use of soap containing triclocarban. Due to the widespread use of triclocarban in adult and infant personal care products, the report prompted us to study its cytotoxicity. The cytotoxicity of triclocarban was examined in rat thymocytes by using a cytometric technique with propidium iodide for examining cell lethality, FluoZin-3-AM for monitoring the intracellular Zn(2+) level, and 5-chloromethylfluorescencein diacetate for estimating the cellular content of non-protein thiol. The incubation with triclocarban at nanomolar concentrations (50-500nM) for 1h did not affect cell lethality but significantly elevated the intracellular Zn(2+) level. The elevation of the intracellular Zn(2+) level by triclocarban was not significantly dependent on external Zn(2+) level. There was a negative correlation (r=-0.9225) between the effect on the intracellular Zn(2+) level and that on the cellular content of non-protein thiol. These results suggest that nanomolar concentrations of triclocarban decrease the cellular content of non-protein thiol, leading to intracellular Zn(2+) release. Since zinc plays physiological roles in mammalian cells, the percutaneous absorption of triclocarban from soap may, therefore, affect some cellular functions.
authors.affiliation: Division of Environmental Symbiosis Studies, Graduate School of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan.
authors.forename: Junpei
authors.initials: J
authors.lastname: Morita
authors.forename: Aoi
authors.initials: A
authors.lastname: Teramachi
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Sanagawa
authors.forename: Saramaiti
authors.initials: S
authors.lastname: Toyson
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Oyama
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002224:Carbanilides / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes; D005786:Gene Expression Regulation / Q000187:drug effects; D011083:Polycyclic Compounds; D051381:Rats; D013194:Staining and Labeling; D060168:Thymocytes / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors; D015032:Zinc / Q000378:metabolism*
chemical_list: D002224:Carbanilides; C451182:FluoZin-3; D005456:Fluorescent Dyes; D011083:Polycyclic Compounds; C009540:triclocarban; D015032:Zinc; D002118:Calcium