Preparation of an extract of pomegranate (A) comprises extracting the fruit pulp with a polar solvent by maceration, infusion, digestion or percolation at = 80[deg]C, filtering, concentrating the solvent, and repeating the process several times to produce a final extract more concentrated in active agents (I) able to amplify the expression of aquaporins (II). Preparation (M1) of an extract of pomegranate (A) comprises : (A) extracting the fruit pulp with a polar solvent by maceration, infusion, digestion or percolation at =80[deg]C； (B) filtering； (C) concentrating the solvent； and (D) repeating the process several times to produce a final extract more concentrated in active agents (I) able to amplify the expression of aquaporins (II). An independent claim is also included for (A) prepared by (M1). ACTIVITY : Dermatological. MECHANISM OF ACTION : Aquaporins (cellular water channels) activator. Cultures of human HaCat keratinocytes were treated with 0, 5, 10 or 15 mu g/ml pomegranate extract (A), and after 72 hours at 37[deg]C, supernatants were removed, the cells rinsed, then fixed and incubated with (a) antibody specific for aquaporin-3 (AQP-3) and (b) goat anti-immunoglobulin G, labeled with fluorescein, followed by examination by fluorescent microscopy. Cells grown in absence of (A) showed very weak fluorescence at the edge of the cells, but those treated with (A) showed a concentration-dependent increase in fluorescence, indicating increased expression of AQP-3.
