title: Phthalate esters reveal skin-sensitizing activity of phenethyl isothiocyanate in mice.
abstract: Phenethyl isothiocyanate (PEITC) is a constituent of edible cruciferous vegetables and has received attention due to its potential cancer chemopreventive activity. Although its protein-binding activity is known, PEITC has not been studied as a contact sensitizer. We previously demonstrated that phthalate esters, including dibutyl phthalate (DBP) and di-n-propyl phthalate (DPP), enhance skin sensitization in a fluorescein isothiocyanate (FITC)-induced contact hypersensitivity mouse model. In this study, we examined whether DBP and DPP enhance skin sensitization to haptens other than FITC. During this study, we tested PEITC as a contact sensitizer. BALB/c mice were epicutaneously sensitized with a suboptimal dose of a hapten with or without a phthalate ester. Sensitization was evaluated as the ear swelling response after a challenge with the respective hapten. DBP and DPP did not enhance the sensitization to two T-helper 1-type (2,4-dinitrofluorobenzene and oxazolone) or three T-helper 2-type (trimellitic anhydride, methylenediphenyl 4,4'-diisocyanate, and tolulene 2,4-diisocyanate) haptens. In contrast, DBP and DPP enhanced the sensitization to two FITC analogues (eosin 5-isothiocyanate and rhodamine B isothiocyanate) as well as to PEITC. Adjuvant effects of DBP and DPP were observed in contact hypersensitivity to haptens other than FITC, including a food ingredient PEITC.
authors.affiliation: Laboratory of Microbiology and Immunology and the Global COE Program, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Matsuda
authors.forename: Takashi
authors.initials: T
authors.lastname: Maruyama
authors.forename: Hiromi
authors.initials: H
authors.lastname: Iizuka
authors.forename: Ayumi
authors.initials: A
authors.lastname: Kondo
authors.forename: Takuma
authors.initials: T
authors.lastname: Tamai
authors.forename: Kohta
authors.initials: K
authors.lastname: Kurohane
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Imai
mesh_terms: D000818:Animals; D004952:Esters; D005260:Female; D017879:Isothiocyanates / Q000633:toxicity*; D051379:Mice; D008807:Mice, Inbred BALB C; D010795:Phthalic Acids / Q000737:chemistry*; D012867:Skin / Q000187:drug effects*
chemical_list: D004952:Esters; D017879:Isothiocyanates; D010795:Phthalic Acids; C058305:phenethyl isothiocyanate