Qualitative screening of phenolic compounds in olive leaf extracts by hyphenated liquid chromatography and preliminary evaluation of cytotoxic activity against human breast cancer cells.

Abstract

In this work, high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and electrospray ion trap multiple-stage tandem mass spectrometry (ESI-IT-MS(2)) has been applied to screen phenolic compounds in olive leaf extracts. The use of a small particle size C18 column (1.8 micro) provided great resolution and made separation of a lot of isomers possible. The structural characterization was based on accurate mass data obtained by ESI-TOF-MS, and the nature of fragmentation ions were further confirmed by ESI-IT-MS(2) when possible. In addition, we employed tetrazolium salt (MTT)-based assays to assess the effects of olive leaf extracts on the growth of human tumor-derived cells. Upon this approach, we achieved an accurate profile of olive leaf phenolics along with the identification of several important isomers of secoiridoids and flavonoids. This will allow a better understanding of the complete composition of olive-leaf-bioactive compounds as well as their involvement in Olea europaea L. biochemical pathways. Importantly, olive leaf extracts exhibited dose-dependent inhibitory effects on the metabolic status (cell viability) of three breast cancer models in vitro. Since the tumoricidal activity of the extracts should be mainly attributed to the identified olive leaf phenolics, these findings warrant further investigation at the structure-function molecular level to definitely establish the anticancer value of these phytochemicals.

• Authors: Shaoping Fu, David Arráez-Roman, Antonio Segura-Carretero, Javier A Menéndez, María P Menéndez-Gutiérrez, Vicente Micol, Alberto Fernández-Gutiérrez
• Journal: Analytical and bioanalytical chemistry (Anal Bioanal Chem) Vol. 397 Issue 2 Pg. 643-54 (May 2010) ISSN: 1618-2650 [Electronic] Germany
• PMID: 20238105 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents, Phytogenic
• Cinnamates
• Flavonoids
• Iridoid Glucosides
• Iridoids
• Phenols
• Pyrans
• cinnamic acid
• oleuropein
• elenolic acid

Topics

• Antineoplastic Agents, Phytogenic (analysis, isolation & purification, pharmacology)
• Breast Neoplasms (drug therapy)
• Carcinoma (drug therapy)
• Cell Survival (drug effects)
• Chromatography, High Pressure Liquid (methods)
• Cinnamates (analysis, isolation & purification, pharmacology)
• Female
• Flavonoids (analysis, isolation & purification, pharmacology)
• Humans
• Iridoid Glucosides
• Iridoids (analysis, isolation & purification, pharmacology)
• Olea (chemistry)
• Phenols (analysis, isolation & purification, pharmacology)
• Plant Leaves (chemistry)
• Pyrans (analysis, isolation & purification, pharmacology)
• Spectrometry, Mass, Electrospray Ionization (methods)
• Tandem Mass Spectrometry (methods)