Experimental study on cross-reactivity of alpha-arbutin toward p-phenylenediamine and hydroquinone in guinea pigs.
Hydroquinone (HQ) has been used as a skin-lightening cosmetic ingredient, while it has been known that HQ shows sensitizing potential and cross-reactivity toward a strong sensitizer, p-phenylenediamine (PPD). alpha-Arbutin, a glycoside of HQ (4-hydroxyphenyl alpha-D-glucopyranoside), is used worldwide as a skin-lightening agent. The aim of this study was to evaluate the cross-reactivity of alpha-arbutin toward PPD and HQ. All tests were performed using the guinea pig maximization test. In experiments on the cross-reactivity of alpha-arbutin or HQ to PPD, six animals in each group were induced with PPD at 0.1% by i.d. injection and at 1.0% by topical application. The animals were challenged with alpha-arbutin, HQ or PPD (as a positive control) at concentrations of 0.01%, 0.05% and 0.1%. In experiments on the cross-reactivity of alpha-arbutin to HQ, four animals in each group were induced with HQ at 2% by i.d. injection and at 1% by topical application. The animals were challenged with alpha-arbutin or HQ (as a positive control) at concentrations of 0.2%, 2% and 20%. The cross-reactivity toward PPD was observed with HQ (4/6) only at 0.1% challenge. However, alpha-arbutin showed no apparent cross-reactivity to either PPD or HQ even at their highest challenge concentrations. Potent sensitization was observed with PPD (6/6) even at 0.01% challenge and with HQ (3/4) at 0.2%. In conclusion, glycosylation of HQ remarkably reduced the sensitization potency of HQ and the cross-reactivity of HQ to PPD.
Health Science Laboratory, Ezaki Glico, Osaka, Japan. too-kenji@glico.co.jp
Kenji
K
To-o
Koji
K
Nomura
Kazuhisa
K
Sugimoto
Takahisa
T
Nishimura
Takashi
T
Kuriki
Masatoshi
M
Itoh
D000818:Animals; D001104:Arbutin / Q000276:immunology*; D003429:Cross Reactions / Q000276:immunology; D003877:Dermatitis, Contact / Q000175:diagnosis / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D006873:Hydroquinones / Q000276:immunology*; D010655:Phenylenediamines / Q000008:administration & dosage / Q000276:immunology*; D012015:Reference Standards; D012880:Skin Pigmentation
D006873:Hydroquinones; D010655:Phenylenediamines; D001104:Arbutin; C029728:4-phenylenediamine; C031927:hydroquinone