IN VITRO ANTITUMOR ACTIVITY OF OLIVE OIL ANTIOXIDANTS TYROSOL AND HYDROXYTYROSOL AND THEIR METHYL CARBONATE DERIVATIVES

SCOPE: A Mediterranean diet rich in olive oil has been associated with health benefits in humans. The phenolic compounds founded in virgin olive oil have demonstrated antitumor activity and antioxidant properties. The aim of this study was to confirm the in vitro antiproliferative effect of tyrosol (Tyr) and hydroxytyrosol (HTyr) on human cancer cell line and to investigate and compare the antitumor effect of methyl carbonate derivatives of these natural compounds as tyrosol methyl carbonate (TyrMC) and hydroxytyrosol methyl carbonate (HTyrMC) synthesized in our laboratory by an eco-friendly procedure. METHODS AND RESULTS Four human tumor cell lines of melanoma (M14), pulmonary (H125), colon (WiDr) and promyelocytic leukaemia (HL60) were growth in the presence of graded concentration of Tyr, HTyr, TyrMC and HTyrMC for 24, 48 and 72 hrs. The antiproliferative activity was assayed by counting the cells in trypan blue, the apoptosis induction and cell cycle profiles were evaluated by flow cytometry analysis. A significant growth inhibition was observed in each tumor cell line exposed to these molecules in the experimental conditions described above. Anyway both TyrMC and HTyrMC compared respectively with Tyr and HTyr result more effective in cell growth inhibition and apoptosis induction. CONCLUSIONS: This study showed that these phenolic compounds exert a significant antiproliferative effect in different tumor cell lines in vitro. The synthesized methyl carbonate derivatives showed a most antiproliferative activity showing a faster apoptosis induction. However, further studies are necessary to better understand the mechanisms of these molecules on tumor cell growth.