Evaluation of potential antigenotoxic, cytotoxic and proapoptotic effects of the olive oil by-product "alperujo", hydroxytyrosol, tyrosol and verbascoside.

Olive oil is an integral ingredient of the "Mediterranean diet". The olive oil industry generates large quantities of a by-product called "alperujo" (AL) during the two-phase centrifugation system developed in the early nineties. AL could be a potent exploitable source of natural phenolic antioxidants. Our results showed that AL and its distinctive phenols hydroxytyrosol, tyrosol and verbascoside were not genotoxic in the Somatic Mutation and Recombination Test (SMART) of Drosophila melanogaster and exerted antigenotoxic activity against DNA oxidative damage generated by hydrogen peroxide (H2O2). Alperujo and hydroxytyrosol also exhibited notable antiproliferative and caspase 3-dependent proapoptotic effects toward the human tumoral cell line HL60. AL can provide a cheap and efficient source of chemopreventive phenolic compounds with strong antioxidant properties, becoming a promising and potent therapeutic drug in the future.