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).
Hydroxytyrosol 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). The distribution among the different forms depends on many factors, such as cultivar, ripening stage, and processing and storage conditions, affecting the hydrolytic activity of endogenous enzymes that release Hty from the secoiridoids. As in the case of other polar phenolics, Hty is more abundant in the by-products of olive oil production, namely olive mill waste
water (OMWW) and pomace, rather than in olive oil itself.
Hydroxytyrosol has been reported to display a number of biological activities, including anticancer, antioxidant, and anti-inflammatory properties. Despite its potential health benefits, its uses in food and cosmetic industries are limited by its hydrophilic character that eventually leads to low bioavailability. Lipophilization has
been suggested as a promising strategy to improve the properties of Hty as well as of other polar phenolics. A number of lipophilic derivatives, including esters bearing fatty acyl chains, have been investigated. Indeed, 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.
The lipophilic character of hydroxytyrosyl esters suggests their potential use as active compounds in epidermal and dermal formulations for the treatment of the inflammation of the cutaneous stratus.
Remarkably, we recently reported on the in vitro anti-inflammatory properties of hydroxytyrosyl oleate. Although no correlation has been established yet, several antimicrobial agents have antioxidant capabilities. In particular, hydroxytyrosyl esters show both antioxidant and antimicrobial activities at significant levels. Reactive Oxygen Species (ROS) are crucial biochemical mediators for senescence and age-related diseases, including disorders of human skin.
MicroRNAs (miRs) have been well recognized as biomarkers of pathology (especially in cancer) and regulators of gene expression by nutrients and nutrition special regimen. Their role in the regulation of antioxidant defense and oxidative stress is emerging. Indeed, dysfunction of the antioxidant defense system and the imbalance between formation and removal of ROS can lead to cell damage due to free radical reactions. Herein we studied the effect of HtyOle as a free radical scavenger on the HaCat human keratinocyte cell line, on ROS formation and antioxidant enzymes, as well as its capability to modulate miRs linked to redox linked to redox cellular state and skin regeneration.
