Hydroxytyrosyl Oleate: Improved Extraction Procedure from Olive Oil and By-Products, and In Vitro Antioxidant and Skin Regenerative Properties.

Cinzia Benincasa,Luca Gallelli,Enzo Perri,Alessia Fazio,Pierluigi Plastina,Chiara La Torre,Maria Cristina Caroleo,Erika Cione,Roberto Cannataro

doi:10.3390/antiox8070233

Abstract

Recently, we identified hydroxytyrosyl oleate (HtyOle) in the by-products of olive oil, pomace and olive mill waste water (OMWW). Herein, we report that HtyOle is more accurately quantified by extracting the phenolic fraction from both matrices by using aqueous methanol (80%). By applying this method, HtyOle was also detected in extra virgin olive oil (EVOO). Since olive oil is used in the preparation of many cosmetic formulations, we explored the antioxidant capacity of HtyOle in human keratinocytes. Formation of reactive oxygen species (ROS) and malondialdehyde (MDA), as well as activity of Glutathione-S-transferase (GST) and superoxide dismutase (SOD) were decreased by HtyOle. In addition to that, microRNAs (miRs) involved in both redox status balance and skin regeneration potential were also tested. The following miRs, hsa-miR-21 and hsa-miR-29a, were increased while has-miR-34a was not affected by HtyOle.

Highlights

Hydroxytyrosol (Hty, Figure 1) is one of the main phenolic compounds in olive fruit
superoxide dismutase (SOD) catalyzes the dismutation of superoxide into oxygen and hydrogen peroxide, and alterations in its activity can lead to unbalanced free radical production
Our experiments showed that SOD and GST activities are decreased by hydroxytyrosyl oleate (HtyOle) treatment, pointing out its action as free radical scavenger per se

Summary

Introduction

Hydroxytyrosol (Hty, Figure 1) is one of the main phenolic compounds in olive fruit. It can occur in its free form, or as a moiety in more complex structures, such as secoiridoids (oleuropein and its aglycone). Hydroxytyrosol has been reported to display a number of biological activities, including anticancer, antioxidant, and anti-inflammatory properties [2,4,5]. Some hydroxytyrosyl esters were found to display enhanced antioxidant activities, compared to parent Hty, and the activity was found to depend on the chain length [7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22]

Methods

Discussion

Conclusion