title: Hydrating skin by stimulating biosynthesis of aquaporins.
abstract: Aquaporins (AQPs) are proteins that facilitate the transport of water across cell membranes. AQP3 expression is related to the expressions of other epidermal proteins involved in water maintenance (ie, CD44, claudin-1, and filaggrin). The expressions of AQP3 water channels are strongly affected by age and chronic sun exposure, and a defective osmotic equilibrium could occur in the epidermis, which would account for the skin dryness observed in older people and skin areas most exposed to sunlight. We investigated active ingredients that are able to increase AQP3 levels in order to improve hydration in human skin keratinocytes. We selected an ethanolic/water (70/30 v/v) extract of Ajuga turkestanica, a plant from Central Asia, as the hydrating agent. After 17 days of treatment every 2 days with this extract (2.5 microg/mL) in vitro, AQP3 expression measured at the protein level in human reconstructed epidermis was significantly increased. Water transport through both aquaporins and aquaglyceroporins and glycerol transport through aquaglyceroporins alone are important to skin hydration. The distribution and the variability of aquaporins in human skin cells suggest that these channels may have important roles in skin physiology. AQPs appear to be key protein targets to improve the resistance and quality of the skin surface as well as to improve aging and sun exposure-induced dryness as shown by their roles in 1) hydrating the living layers of the epidermis where the keratinocyte differentiation takes place and 2) barrier formation and recovery.
authors: LVMH Recherche - Parfum Christian Dior, St. Jean de Braye, France. mdumas@research.lvmh-pc.com
authors: Marc
authors: M
authors: Dumas
authors: Neil S
authors: NS
authors: Sadick
authors: Emmanuelle
authors: E
authors: Noblesse
authors: Milène
authors: M
authors: Juan
authors: Nadège
authors: N
authors: Lachmann-Weber
authors: Mathieu
authors: M
authors: Boury-Jamot
authors: Rachid
authors: R
authors: Sougrat
authors: Jean Marc
authors: JM
authors: Verbavatz
authors: Sylvianne
authors: S
authors: Schnebert
authors: Frédéric
authors: F
authors: Bonté
mesh_terms: D000328:Adult; D031328:Ajuga; D051400:Aquaporin 3 / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D000091344:Filaggrin Proteins; D006801:Humans; D008875:Middle Aged; D009997:Osmotic Pressure; D010936:Plant Extracts / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D012867:Skin / Q000737:chemistry; D015595:Skin Aging / Q000187:drug effects*
chemical_list: C496027:AQP3 protein, human; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D010936:Plant Extracts; D012333:RNA, Messenger; D051400:Aquaporin 3