Expression of differential genes involved in the maintenance of water balance in human skin by Piptadenia colubrina extract Maria Del Carmen Velazquez Pereda, PhD, 1,2 Gustavo de Campos Dieamant, PhD, 1,2 Samara Eberlin, PhD, 1,2 Rejane Maria Werka, 1,2 De ´ bora Colombi, PhD, 3 Mary Luci de Souza Queiroz, PhD, 1 & Luiz Claudio Di Stasi, PhD 4 1 Department of Pharmacology ⁄ Hemocenter, University of Campinas (UNICAMP), Campinas, Brazil 2 Research and Development Department, Chemyunion Quı´mica Ltda, Sorocaba, Brazil 3 Department of Genetics, Sa ˜o Paulo State University (UNESP), Botucatu, Brazil 4 Department of Pharmacology, Sa ˜o Paulo State University (UNESP), Botucatu, Brazil Summary Background Hydration and integrity of the stratum corneum (SC) is an important determinant of skin appearance, metabolism, mechanical properties, and barrier function. The presence of aquaglyceroporins and envelope proteins are crucial to provide greater corneocyte cohesion to keep water and other moisturizers in the skin. Aims In this study, we evaluated the ability of Piptadenia colubrina, a plant native of South American rain forests, in the expression of genes involved in skin capacitance and SC integrity. Methods The expression of genes for aquaporin-3 (AQP3), loricrin, involucrin (INV), and filaggrin (FLG) was measured by real-time PCR, using an in vitro model of human keratinocytes incubated with concentrations of 2.5, 5, 10, and 20 mg ⁄ mL of a hy- droglycolic extract of P. colubrina (HEPC). The amount of AQP3 protein was also tested by immunohistochemistry in human skin explants. Clinical trials were conducted to evaluate the effects of a gel-cream containing HEPC on the glycerol index and skin capacitance. Results Hydroglycolic extract of P. colubrina increased both the expression and immu- noreactivity of AQP3 in cultured keratinocytes and human skin explants. The gene induction to envelope proteins FLG and INV was also observed after cell incubation with HEPC. Skin capacitance was significantly improved in human volunteers under treat- ment with HEPC-containing cream. Conclusions The extract of P. colubrina promotes cellular hydration and induces gene expression of envelope proteins providing greater corneocyte cohesion to keep water and other moisturizers in the skin and an appropriate epidermal adhesion. The in vitro findings were clinically confirmed and encourage the clinical use of this compound in skin care products. Keywords: Piptadenia colubrina, aquaporin-3, cornified envelope, filaggrin, involucrin, glycerol Introduction The outermost region of the skin establishes and maintains an effective barrier that controls water exchange and protects against dehydration, 1 which is Correspondence: Samara Eberlin, PhD, Research and Development Department, Chemyunion Quı´mica Ltda, Rua Jose ´ de Oliveira Cassu ´ 447, E ´ den, Sorocaba-SP, 18103-065, Brazil. E-mail: samara@chemyunion.com.br Accepted for publication July 21, 2009 Original Contribution Ó 2010 Wiley Periodicals, Inc. • Journal of Cosmetic Dermatology, 9, 35–43 35