title: Skin roughness and wrinkle formation induced by repeated application of squalene-monohydroperoxide to the hairless mouse.
abstract: The present study examines the cumulative effects of sub-erythema application of squalene-monohydroperoxide (Sq-OOH), the initial products of UV-peroxidated squalene, to the skin of hairless mice. Sq-OOH was isolated by the methanol extraction and preparative HPLC method. Repeated topical application of 10 mM Sq-OOH to hairless mice for 3 weeks induced definite skin roughness and crinkle formation. 3-D surface parameter analysis revealed changes in all roughness parameters (number of furrows and crests, distance between a furrow and next crest, and irregularity) of the group treated with more than 3 mM Sq-OOH compared to the control group. These skin surface changes were not induced by squalene, squalene-monohydroxide (Sq-OH) or organic hydroperoxides such as tert-butyl hydroperoxide and cumene-hydroperoxide at 10 mM. Similarly, such changes were not induced by primary irritants, such as sodium lauryl sulfate and n-tetradecane under the same experimental conditions. Skin conductance decreased, following application of 10 mM Sq-OOH. Histological observation revealed that application of 10 mM Sq-OOH induced slight hyperkeratosis, moderate epidermal thickening and slight hyperplasia of sebaceous glands.
authors.affiliation: Yakult Institute for Microbiological Research, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Chiba
authors.forename: T
authors.initials: T
authors.lastname: Sone
authors.forename: K
authors.initials: K
authors.lastname: Kawakami
authors.forename: M
authors.initials: M
authors.lastname: Onoue
mesh_terms: D000287:Administration, Topical; D000818:Animals; D001834:Body Water / Q000187:drug effects / Q000378:metabolism; D004553:Electric Conductivity; D005260:Female; D051379:Mice; D008812:Mice, Hairless; D012867:Skin / Q000187:drug effects* / Q000293:injuries* / Q000473:pathology; D015595:Skin Aging / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D013185:Squalene / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000528:radiation effects / Q000633:toxicity; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: C002821:2,3-oxidosqualene; D013185:Squalene