1 Viability-reducing activity of Coryllus avellana L. extracts against human cancer 1 cell lines 2 Ana Gallego a , Isidoro Metón b , Isabel V Baanante b , Jamal Ouazzani c , Emilie Adelin c , 3 Javier Palazon d , Mercedes Bonfill d† , Elisabeth Moyano a * † 4 5 a Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, 6 Avda. Dr. Aiguader 80, E-08003, Barcelona, Spain. 7 b Departament de Bioquímica i Fisiologia. Secció de Bioquímica i Biologia Molecular, 8 Facultad de Farmacia i Ciències de l’Alimentació. Universitat de Barcelona, Avda. Joan 9 XXIII 27-31, E-08028 Barcelona, Spain. 10 c Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles ICSN, 11 Centre National de la Recherche Scientifique, CNRS, Avenue de la Terrasse 91198, 12 Gif-sur-Yvette cedex, France. 13 d Laboratori de Fisiologia Vegetal, Facultat de Farmàcia i Ciències de l’Alimentació. 14 Universitat de Barcelona, Avda. Joan XXIII 27-31, E-08028 Barcelona, Spain. 15 *Corresponding author. Tel: +34 934020267; Fax: +34 934029043 16 E-mail address: elisabeth.moyano@upf.edu (E. Moyano) 17 † These authors contributed equally to this manuscript. 18 19 Abstract 20 The increasing rate of cancer incidence has encouraged the search for novel natural 21 sources of anticancer compounds. The presence of small quantities of taxol and taxanes 22 in Corylus avellana L. has impelled new potential applications for this plant in the field 23 of biomedicine. In the present work, the cell viability-reducing activity of stems and 24 leaves from three different hazel trees was studied against three human-derived cancer 25 cell lines (HeLa, HepG2 and MCF-7). Both leaf and stem extracts significantly reduced 26