The Mediterranean diet, and even more the Cretan diet, has been associated with beneficial effects on human health, in terms of lowering the occurence of chronic diseases, such as coronary artery disease, atherosclerosis and cancer. Studies have concluded that the high life expectancy of the Cretans is attributed to their dietary habits, i.e. the high intake of vegetables, wild herbs and aromatic plants and mainly in high olive oil consumption.
Olive oil serves as the principal source of dietary fat, and it is known from the ancient years for its therapeutic properties. It contains a number of highly bioactive metabolites, such as oleuropein (OE), hydroxytyrosol (HT), tyrosol (T), elenolic acid (EA) etc. with antioxidant properties that prevent lipoprotein oxidation, which is considered to be a key factor in the pathogenesis of atherosclerosis. These substances possess anticancer, antibacterial and antiatherogenic properties and recent reports have shown a preventing effect for illnesses affecting the elderly, such as the Alzheimer's disease. Therefore, the determination, metabolic pathway, as well as the bioavailability of the aforementioned substances are of vital importance towards the understanding of the biological importance of the Mediterranean diet.
In this report, the estrogenic, as well as the antiinflammatory activity of these compounds is assessed by administering OE and olive oil to Wistar rats of which ovaries have been removed and then by measuring the total amount present in their biological fluids. The study aims at evaluating the efficiency of these compounds to act as ligands to the estrogenic receptor and consequently to inhibit the appearance of osteoporosis. At the same time inflammation was induced to these rats in order to examine the antioxidant as well as the antiinflammatory capacity of the compounds under study.
Analytical methodology based on chromatographic (SPE-GC, SPE-LC), spectroscopic (UV-DAD) and mass spectrometric techniques (SIM, MS, MS/MS) was developed for the simultaneous determination of OE and its metabolites in rat urine and plasma, and human plasma. This methodology enabled the determination of the levels for the aforementioned substances in blood and urine, thus providing insights into their biological activity.
Fotini Bazoti, Antonis Tsarbopoulos, University of Patras, Greece
GAIA Research Center, The Goulandris Natural History Museum, Greece
Evangelos Gikas, GAIA Research Center, The Goulandris Natural History Museum, Greece