title: Use of advanced techniques for the extraction of phenolic compounds from Tunisian olive leaves: phenolic composition and cytotoxicity against human breast cancer cells.
abstract: A comparison among different advanced extraction techniques such as microwave-assisted extraction (MAE), supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), together with traditional solid-liquid extraction, was performed to test their efficiency towards the extraction of phenolic compounds from leaves of six Tunisian olive varieties. Extractions were carried out at the best selected conditions for each technique; the obtained extracts were chemically characterized using high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and electrospray ion trap tandem mass spectrometry (ESI-IT-MS(2)). As expected, higher extraction yields were obtained for PLE while phenolic profiles were mainly influenced by the solvent used as optimum in the different extraction methods. A larger number of phenolic compounds, mostly of a polar character, were found in the extracts obtained by using MAE. Best extraction yields do not correlate with highest cytotoxic activity against breast cancer cells, indicating that cytotoxicity is highly dependent on the presence of certain compounds in the extracts, although not exclusively on a single compound. Therefore, a multifactorial behavior is proposed for the anticancer activity of olive leaf compounds.
authors.affiliation: Laboratoire Caractérisation et Qualité de l'Huile d'Olive, Centre de Biotechnologie de Borj Cedria, BP 901, 2050 Hammam-Lif, Tunisia.
authors.forename: Amani
authors.initials: A
authors.lastname: Taamalli
authors.forename: David
authors.initials: D
authors.lastname: Arráez-Román
authors.forename: Enrique
authors.initials: E
authors.lastname: Barrajón-Catalán
authors.forename: Verónica
authors.initials: V
authors.lastname: Ruiz-Torres
authors.forename: Almudena
authors.initials: A
authors.lastname: Pérez-Sánchez
authors.forename: Miguel
authors.initials: M
authors.lastname: Herrero
authors.forename: Elena
authors.initials: E
authors.lastname: Ibañez
authors.forename: Vicente
authors.initials: V
authors.lastname: Micol
authors.forename: Mokhtar
authors.initials: M
authors.lastname: Zarrouk
authors.forename: Antonio
authors.initials: A
authors.lastname: Segura-Carretero
authors.forename: Alberto
authors.initials: A
authors.lastname: Fernández-Gutiérrez
mesh_terms: D000704:Analysis of Variance; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy*; D045744:Cell Line, Tumor; D002470:Cell Survival; D002851:Chromatography, High Pressure Liquid; D025924:Chromatography, Supercritical Fluid; D005260:Female; D006801:Humans; D008872:Microwaves; D031658:Olea / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014416:Tunisia
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010636:Phenols; D010936:Plant Extracts; D012997:Solvents