title: Cetylpyridinium chloride at sublethal levels increases the susceptibility of rat thymic lymphocytes to oxidative stress.
abstract: Cetylpyridinium chloride (CPC) is an antimicrobial agent used in many personal care products, with subsequent release into the environment. Since CPC is found at low concentrations in river and municipal wastewater, its influence on wildlife is of concern. Therefore, in this study, we used flow cytometry to examine the effects of sublethal concentrations of CPC on rat thymic lymphocytes in order to characterize the cellular actions of CPC at low concentrations in the presence and absence of H2O2-induced oxidative stress. CPC treatment increased the population of living cells with phosphatidylserine exposed on the outer surface of their plasma membranes (a marker of early stage apoptosis), elevated intracellular Zn2+levels, and decreased the cellular content of nonprotein thiols. CPC also potentiated the cytotoxicity of H2O2. Our results suggest that, even at environmentally relevant sublethal concentrations, CPC exerts cytotoxic effects under oxidative stress conditions by increasing intracellular Zn2+concentration and decreasing the cellular content of nonprotein thiols. These findings indicate that, under some in vitro conditions, CPC is bioactive at environmentally relevant concentrations. Therefore, CPC release from personal care products into the environment may need to be regulated to avoid its adverse effects on wildlife.
authors.affiliation: Graduate School of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Imai
authors.affiliation: Graduate School of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan.
authors.forename: Fumiya
authors.initials: F
authors.lastname: Kita
authors.affiliation: Graduate School of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Ikesugi
authors.affiliation: Graduate School of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Abe
authors.affiliation: Graduate School of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan.
authors.forename: Shizuka
authors.initials: S
authors.lastname: Sogabe
authors.affiliation: Graduate School of Biomedical Sciences and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishimura-Danjobara
authors.affiliation: Graduate School of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan; Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Miura
authors.affiliation: Graduate School of Integrated Arts and Sciences, Tokushima University, Tokushima 770-8502, Japan; Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan. Electronic address: oyamay@tokushima-u.ac.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Oyama
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002594:Cetylpyridinium / Q000737:chemistry*; D004198:Disease Susceptibility; D005434:Flow Cytometry; D005453:Fluorescence; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008214:Lymphocytes / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D013438:Sulfhydryl Compounds / Q000378:metabolism; D060168:Thymocytes / Q000187:drug effects*; D013950:Thymus Gland / Q000187:drug effects*; D015032:Zinc
chemical_list: D013438:Sulfhydryl Compounds; D006861:Hydrogen Peroxide; D002594:Cetylpyridinium; D015032:Zinc
keywords: Cetylpyridinium chloride; Cytotoxicity; Hydrogen peroxide; Oxidative stress; Thymocytes; Zinc