Oleuropein: A Potential Inhibitor for Prostate Cancer Cell Motility by Blocking Voltage-Gated Sodium Channels

In this study, we investigated whether olive leaf and oleuropein have the potential to stop cell motility, which a metastatic cell behavior by blocking voltage-gated sodium channels (VGSCs). For this purpose, it was first prepared the aqueous extract of olive leaves (AOLE). Then it was assayed the effect on the motility of MAT-LyLu, a highly metastatic Dunning rat prostate adenocarcinoma cells of this extract. The phenolic content of AOLE was analyzed using LC-MS/MS instrument. It was observed that oleuropein was the most finding compound in AOLE. Therefore, whether oleuropein was responsible for the inhibitory effect of AOLE on the MAT-LyLu cell movement was tested. Nontoxic oleuropein concentrations and those that did not affect proliferation on MAT-LyLu cells were determined. Subsequently, it was examined the effects of oleuropein on the lateral and vertical movement of MAT-LyLu cells. To elucidate the mechanism of oleuropein affecting cell motility, whether it suppressed mRNA expression of SCN9A, which encodes the VGSC was analyzed. Accordingly, oleuropein suppressed the movement of MAT-LyLu cells by reducing SCN9A mRNA expression. In conclusion, we report the first time that oleuropein might be considered as a potential antimetastatic agent for prostate cancer due to its blocking effect on VGSC-mediated cell motility.