Adapalene, a synthetic naphthoic acid derivative, is a selective agonist of retinoic acid receptor (RAR)-β and RAR-γ (Kds = 34 and 130 nM, respectively). At 0.1-10 μM, adapalene dose-dependently inhibits sebocyte growth, proliferation, and differentiation in a primary rat preputial cell culture system. Adapalene demonstrates anti-inflammatory and immunomodulatory activity by inhibiting 5-lipoxygenase-catalyzed leukotriene production and expression of toll-like receptor 2 on human monocytes. It is commonly used for the study of the pathogenesis and treatment of acne vulgaris.
