title: Depigmentation of black guinea pig skin by topical application of cysteaminylphenol, cysteinylphenol, and related compounds.
abstract: Phenol and catechol were combined with sulfur to develop new melanocytotoxic agents. Among these synthetic compounds, 4-S-cysteaminylphenol (4-S-CAP) and 4-S-cysteinylphenol (4-S-CP), which showed an in vivo antimelanoma effect, were evaluated for cytotoxicity to normal epidermal melanocytes using hydroquinone (HQ) as the control. Topical application of 4-S-CAP on the skin of black guinea pigs revealed a marked depigmentation of black skin. 4-S-Cysteinylphenol also showed some depigmenting potency. 2-S-Cysteinylhydroquinone, which was made by combining cystine with HQ, on the other hand, did not show any depigmenting effect. Depigmentation of black skin by 4-S-CAP appeared to derive from: a decrease in the number of functioning melanocytes; a decrease in the number of melanosomes synthesized within the melanocytes and transferred to keratinocytes; and destruction of the membranous organelles of the melanocytes. None of these degenerative changes was observed in the keratinocytes, indicating the selective effect of 4-S-CAP on melanocytes.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D003543:Cysteamine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000633:toxicity; D003545:Cysteine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000633:toxicity; D004817:Epidermis / Q000187:drug effects* / Q000648:ultrastructure; D006168:Guinea Pigs; D007980:Levodopa / Q000378:metabolism; D008544:Melanocytes / Q000187:drug effects* / Q000648:ultrastructure; D012880:Skin Pigmentation / Q000187:drug effects*; D014820:Vitiligo / Q000139:chemically induced*
chemical_list: C040165:2-(S-cysteinyl)hydroquinone; D007980:Levodopa; D003543:Cysteamine; C043036:4-S-cysteinylphenol; C043037:4-S-cysteaminylphenol; D003545:Cysteine