P-Glycoprotein Inhibitory Activity of Lipophilic Constituents of Echinacea pallida Roots in a Human Proximal Tubular Cell Line - Romiti, Nadia; Pellati, Federica; Nieri, Paola; Benvenuti, Stefania; Adinolfi, Barbara; Chieli, Elisabetta (Planta Medica, 2008)