Ex vivo demonstration of a synergistic effect of Adapalene and benzoyl peroxide on inflammatory acne lesions

Exp Dermatol. 2011 Oct;20(10):850-3. doi: 10.1111/j.1600-0625.2011.01339.x. Epub 2011 Jul 24.


Acne is a chronic inflammatory disease of the pilosebaceous follicle. Thanks to its ability to reduce both comedones and inflammatory lesions, the association of a retinoid and benzoyl peroxide (BPO) is now recommended for the treatment of acne. However, the mechanisms of action of this combined therapy on inflammatory acne lesions are not well understood. In an ex vivo immunohistochemistry study, we investigated the potential synergistic modulator effect of Adapalene associated with BPO on keratinocytes proliferation/differentiation and innate immunity in inflammatory acne lesions. We demonstrated that proliferation (Ki-67), adhesion/differentiation (integrin α(2), α(3) and α(6)) and innate immunity (TLR-2, β-defensin 4, IL-8) markers are overexpressed in inflammatory acne skin compared with uninvolved acne skin. Association of Adapalene and BPO significantly decreased expression of Ki67, α(2) and α(6) integrins, TLR-2, β-defensin 4 and IL-8 in inflammatory acne skin, whereas single treatments with Adapalene or BPO alone were less effective. These results contribute to explain the comedolytic and anti-inflammatory activities of this combined therapy observed in recent clinical trials.

Publication types

  • Letter
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acne Vulgaris / drug therapy*
  • Acne Vulgaris / immunology
  • Acne Vulgaris / pathology
  • Adapalene
  • Adult
  • Anti-Inflammatory Agents, Non-Steroidal / administration & dosage
  • Benzoyl Peroxide / administration & dosage*
  • Cell Differentiation / drug effects
  • Cell Proliferation / drug effects
  • Dermatologic Agents / administration & dosage
  • Drug Synergism
  • Drug Therapy, Combination
  • Female
  • Humans
  • Immunity, Innate / drug effects
  • Immunohistochemistry
  • In Vitro Techniques
  • Integrins / metabolism
  • Male
  • Naphthalenes / administration & dosage*
  • Young Adult
  • beta-Defensins / metabolism


  • Anti-Inflammatory Agents, Non-Steroidal
  • Dermatologic Agents
  • Integrins
  • Naphthalenes
  • beta-Defensins
  • Adapalene
  • Benzoyl Peroxide