Antioxidant and anticancer efficacy of therapeutic bioactive compounds from fermented olive waste

Olive pomace, which is considered as one of the worst agro-industrial wastes in Mediterranean countries was tested for bioactive compounds production through the solid state fermentation of Kluyveromyces marxianus . Because they present potent biological activities, phenolic compounds from both unfermented and fermented pomace were extracted with simultaneous evaluation of their antioxidant and anticancer activities. Conditions for optimum total phenolic recovery with maximum antioxidant activity were optimized using methanol as the extracting solvent with a sample to solvent ratio of 1:10 at 50 °C for 2 hours. The in-vitro anticancer activity of both extracts was assessed against different human cancer cell lines. The results revealed that both extracts exerted anticancer effects close to the value of doxorubicin drug against liver HepG2 and breast MCF-7 cell lines, and moderate activity against prostate PC3 and colon HCT116 cell lines. Nevertheless, the fermented extract was more potent than the unfermented one. No effect against lung A549, cervix Hela cancer cell lines or normal HFB4 cells was observed for both extracts. A GC/MS analysis was carried out to determine the compounds responsible for antioxidant and anticancer activities. The results showed the presence of methyl palmitate, methyl oleate, and ethyl oleate in the methanolic extract of unfermented olive pomace, while that of the fermented one showed the production of carvacrol, thymol, eugenol, caryophyllene oxide and methyl isopalmitate.