1. Academic Validation
  2. Oleuropein, the Main Polyphenol of Olea europaea Leaf Extract, Has an Anti-Cancer Effect on Human BRAF Melanoma Cells and Potentiates the Cytotoxicity of Current Chemotherapies

Oleuropein, the Main Polyphenol of Olea europaea Leaf Extract, Has an Anti-Cancer Effect on Human BRAF Melanoma Cells and Potentiates the Cytotoxicity of Current Chemotherapies

  • Nutrients. 2018 Dec 8;10(12):1950. doi: 10.3390/nu10121950.
Jessica Ruzzolini 1 Silvia Peppicelli 2 Elena Andreucci 3 Francesca Bianchini 4 Arianna Scardigli 5 Annalisa Romani 6 Giancarlo la Marca 7 Chiara Nediani 8 Lido Calorini 9 10
Affiliations

Affiliations

  • 1 Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy. [email protected].
  • 2 Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy. [email protected].
  • 3 Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy. [email protected].
  • 4 Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy. [email protected].
  • 5 PHYTOLAB (Pharmaceutical, Cosmetic, Food Supplement Technology and Analysis)-DiSIA, Scientific and Technological Pole, University of Florence, 50134 Florence, Italy. [email protected].
  • 6 PHYTOLAB (Pharmaceutical, Cosmetic, Food Supplement Technology and Analysis)-DiSIA, Scientific and Technological Pole, University of Florence, 50134 Florence, Italy. [email protected].
  • 7 Mass Spectrometry Laboratory, Clinic of Pediatric Neurology, Meyer University Children's Hospital, 50139 Florence, Italy. [email protected].
  • 8 Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy. [email protected].
  • 9 Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134 Florence, Italy. [email protected].
  • 10 Istituto Toscano Tumori and Center of Excellence for Research, Transfer and High Education DenoTHE University of Florence, 50139 Florence, Italy. [email protected].
Abstract

Oleuropein (Ole), a secoiridoid glucoside present in Olea europaea leaves, gained scientific interest thanks to its several biological properties, including the Anticancer one. We verified whether Ole might potentiate the cytotoxicity of conventional drugs used to treat melanoma, disclosing a potentially new therapeutic strategy. We tested the cytotoxic action of Ole alone or in combination with chemotherapeutics on A375 human melanoma cells. We found that Ole was able, at a dose of 500 µM, to stimulate Apoptosis, while at a non-toxic dose of 250 µM, it affected cell proliferation and induced the downregulation of the pAKT/pS6 pathway. A dose of 250 µM Ole did not potentiate the effect of Vemurafenib (PLX4032), but it succeeded in increasing the cytotoxic effect of Dacarbazine (DTIC). The major effect was found in the association between Ole and Everolimus (RAD001), also on PLX4032-resistant BRaf melanoma cells, which possibly cooperate in the inhibition of the pAKT/pS6 pathway. Of interest, an olive leaf extract enriched in equimolar Ole was more effective and able to further improve DTIC and RAD001 efficacy on BRaf melanoma cells with respect to Ole alone. Therefore, Ole represents a natural product able to potentiate a wide array of chemotherapeutics against BRaf melanoma cells affecting the pAKT/pS6 pathway.

Keywords

BRAF melanoma; Oleuropein; chemotherapeutics; extra virgin oil; olive leaf extract.

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