title: Basal cell proliferation in female SKH-1 mice treated with alpha- and beta-hydroxy acids.
abstract: Alpha- and beta-hydroxy acids are compounds that have been used extensively in cosmetic and dermatological formulations. Clinical and qualitative effects of alpha- and beta-hydroxy acids have been well characterized, but little is known about their mechanism of action or acute and chronic biochemical effects. In the present study, we examined the acute proliferative effects of glycolic and salicylic acids on cell proliferation in the epidermis of SKH-1 female mice, using BrdU incorporation as a marker of epidermal proliferation. In preliminary experiments, we observed an increase in the rate of proliferation after 3 days of treatment with 10% glycolic acid-containing cream and this was sustained throughout a 6.5-week (treatment 5 days/week) time course compared with untreated control animals. After each treatment with cream containing glycolic acid there was a wave of proliferation that was maximal 12 to 16 h (significant at p < 0.05) after treatment, followed by a subsequent increase in epidermal thickness at 18 to 20 h (significant at p < 0.05). The effects of the concentration and pH level of glycolic acid- and salicylic acid-containing creams on the rate of proliferation and increases in skin thickness in SKH-1 epidermis were also investigated. We observed a dose-dependent increase in epidermal proliferation of animals treated with either glycolic or salicylic acid. A similar time-dependent response was observed in the epidermal thickness in animals treated with salicylic acid, but not with glycolic acid. Differences in pH (3.5 or 4.0) had no significant effect on either epidermal proliferation or skin thickness. The data that we present here should be useful in characterizing not only the beneficial but also the adverse effects that occur following acute or chronic usage of alpha-hydroxy acids.
authors.affiliation: Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food & Drug Administration, Jefferson, Arkansas 72079, USA. RSAMS@nctr.fda.gov
authors.forename: R L
authors.initials: RL
authors.lastname: Sams
authors.forename: L H
authors.initials: LH
authors.lastname: Couch
authors.forename: B J
authors.initials: BJ
authors.lastname: Miller
authors.forename: C V
authors.initials: CV
authors.lastname: Okerberg
authors.forename: A
authors.initials: A
authors.lastname: Warbritton
authors.forename: W G
authors.initials: WG
authors.lastname: Wamer
authors.forename: J Z
authors.initials: JZ
authors.lastname: Beer
authors.forename: P C
authors.initials: PC
authors.lastname: Howard
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D003358:Cosmetics / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006016:Glycolates / Q000494:pharmacology*; D007641:Keratolytic Agents / Q000494:pharmacology*; D051379:Mice; D020156:Salicylic Acid / Q000494:pharmacology*
chemical_list: D003358:Cosmetics; D006016:Glycolates; D007641:Keratolytic Agents; C031149:glycolic acid; D020156:Salicylic Acid