title: Comparative effects of retinoic acid, glycolic acid and a lipophilic derivative of salicylic acid on photodamaged epidermis.
abstract: BACKGROUND
  Studies comparing purported antiaging compounds are rare.
  
  
  OBJECTIVE
  To compare in a randomized, placebo-controlled double-blind study 10% glycolic acid (GA), 2% 2-hydroxy-5-octanoyl benzoic acid (beta-lipohydroxy acid, LSA) and 0.05% all-trans-retinoic acid (RA).
  
  
  METHODS
  Women volunteers treated one forearm twice daily with one of the active products and the other one with the vehicle. Comparative evaluations of efficacy were made using histochemistry and quantitative immunohistochemistry.
  
  
  RESULTS
  Improvement in the various epidermal compartments was the most prominent finding at the RA-treated site. The LSA-treated site also exhibited similar positive changes, although to a lesser degree. GA showed no significant effect.
  
  
  CONCLUSIONS
  In the presently tested concentrations and formulations, RA had a beneficial impact upon the aging epidermis. LSA mimicked RA but with somewhat lesser efficacy. By contrast, GA appeared almost inactive.
authors.affiliation: Department of Dermatopathology, University of Liège, Belgium.
authors.forename: G E
authors.initials: GE
authors.lastname: Pi rard
authors.forename: A M
authors.initials: AM
authors.lastname: Kligman
authors.forename: T
authors.initials: T
authors.lastname: Stoudemayer
authors.forename: J L
authors.initials: JL
authors.lastname: Lévêque
mesh_terms: D004311:Double-Blind Method; D004817:Epidermis / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects; D005260:Female; D000091344:Filaggrin Proteins; D006016:Glycolates / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000032:analysis; D007633:Keratins / Q000032:analysis; D007641:Keratolytic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D019394:Ki-67 Antigen / Q000032:analysis; D037102:Lectins / Q000032:analysis; D008875:Middle Aged; D037121:Plant Lectins; D012459:Salicylates / Q000009:adverse effects / Q000627:therapeutic use; D012867:Skin / Q000737:chemistry / Q000473:pathology; D012871:Skin Diseases / Q000139:chemically induced; D011503:Transglutaminases / Q000032:analysis; D016896:Treatment Outcome; D014212:Tretinoin / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: C113468:2-hydroxy-5-octanoylbenzoic acid; D000091344:Filaggrin Proteins; D006016:Glycolates; D007381:Intermediate Filament Proteins; D007641:Keratolytic Agents; D019394:Ki-67 Antigen; D037102:Lectins; D037121:Plant Lectins; D012459:Salicylates; C036850:Ulex europaeus lectins; C031149:glycolic acid; D014212:Tretinoin; D007633:Keratins; D011503:Transglutaminases