title: Structure-activity relationship of a series of 17 parabens and related compounds for histamine release in rat peritoneal mast cells and skin allergic reaction in guinea pigs.
abstract: Parabens, which are a homologous series of esters of p-hydroxybenzoic acid, have been used as preservatives in cosmetics, medicines and foods because of their antimicrobial activity. However, parabens in cosmetics have been suspected to cause allergic contact dermatitis. In this study, we examined paraben-induced histamine release from rat peritoneal mast cells and skin reaction in guinea pigs using a series of 17 parabens with different alcohol side chains, ranging from methylparaben to dodecylparaben. Octylparaben showed the greatest histamine release-inducing activity from mast cells, and the activity was decreased in shorter- and longer-side-chain parabens. Octyl benzoate, octyl o-hydroxybenzoate and phenyloctane caused no significant degranulation of mast cells, whereas octyl m-hydroxybenzoate, octyl p-hydroxybenzoate and octyl phenol induced concentration-related degranulation. Metabolites of these parabens (p-hydroxybenzoic acid and alcohols) did not show histamine release-inducing activity. In the guinea pig skin reaction test, heptylparaben induced a typical strong skin reaction, while butylparaben induced a typical weak skin reaction, and methylparaben and dodecylparaben were inactive. Metabolites of parabens (p-hydroxybenzoic acid and alcohols) were also inactive. These results indicate that interaction of parabens with rat mast cells requires a minimum length and adequate lipophilicity of the alkyl side chain. Since metabolites of parabens were inactive, parabens appear to be direct-acting allergens.
authors.affiliation: Nihon Pharmaceutical University.
authors.forename: Naoto
authors.initials: N
authors.lastname: Uramaru
authors.forename: Toshio
authors.initials: T
authors.lastname: Inoue
authors.forename: Yoko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Hidenari
authors.initials: H
authors.lastname: Shigematsu
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohta
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kitamura
mesh_terms: D000485:Allergens; D000818:Animals; D002478:Cells, Cultured; D017449:Dermatitis, Allergic Contact / Q000209:etiology* / Q000276:immunology; D005520:Food Preservatives / Q000009:adverse effects*; D006168:Guinea Pigs; D006636:Histamine Release / Q000187:drug effects*; D008297:Male; D008407:Mast Cells / Q000378:metabolism*; D010226:Parabens / Q000009:adverse effects* / Q000737:chemistry; D010537:Peritoneum / Q000166:cytology*; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects*; D051381:Rats; D017208:Rats, Wistar; D012882:Skin Tests; D013329:Structure-Activity Relationship
chemical_list: D000485:Allergens; D005520:Food Preservatives; D010226:Parabens; D011310:Preservatives, Pharmaceutical