In vitro antitumor and hypotensive activity of peptides from olive seeds

Peptides with molecular weights below 3 kDa from the hydrolysis of olive seed proteins with Thermolysin (OS-3 kDa) have demonstrated a high in vitro hypotensive effect. This fraction has been further fractionated by semipreparative RP-HPLC to obtain 8 fractions. ACE inhibitor capacity of fractions was evaluated observing the highest capacity in fraction F5. Peptides in fraction F5 were identified by RP-HPLC- and HILIC-ESI-Q-ToF and cytotoxic effect was assessed in different cell lines. Peptide LLPSY, present in this faction, was synthesized and characterized. Despite antihypertensive capacity was not as high as in fraction F5, a significant anti-proliferative capacity on two different cancer cell lines was observed. Additional studies to assess antitumor activity confirmed that this peptide showed capability to increase the adhesion capacity of tumor cells, to decrease the migration capacity of cancer cells, and to arrest cell cycle on S phase.