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

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.

Potential Beneficial Effects of Extra Virgin Olive Oils Characterized by High Content in Minor Polar Compounds in Nephropathic Patients: A Pilot Study

“…Olive oil phenols have powerful antioxidant, anticancer, and anti-inflammatory activity [ 3 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. The presence and content of these compounds are the basis of a health claim approved by the European Food Safety Authority (EFSA) in 2012 [ 19 ], which states that “olive oil polyphenols contribute to the protection of blood lipids from oxidative stress”.…”

Epigenetic Modifications Induced by Olive Oil and Its Phenolic Compounds: A Systematic Review

“…Therefore, at the end of the selection process, 43 studies were included in the systematic review ( Figure 1 ). Among them, 18 reported data on miRNAs [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ], 10 on DNA methylation [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ], 9 on histone modification [ 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ], 2 on histone modification/DNA methylation [ 58 , 59 ], 2 on miRNAs/DNA methylation [ 60 , 61 ] one each on miRNA/histone modification [ 62 ] and on miRNA/histone modification/DNA methylation [ 63 ] ( Figure 1 ).…”

“…The characteristics of the 22 selected studies investigating the effects of olive oil and its phenolic compounds on miRNA expression are shown in Table S1 . Sixteen studies reported data in vitro on different cell systems [ 21 , 22 , 24 , 26 , 27 , 28 , 30 , 31 , 32 , 34 , 35 , 36 , 37 , 38 , 60 , 63 ], 9 studies showed results on animal models [ 23 , 24 , 29 , 30 , 33 , 60 , 61 , 62 ] and 2 studies reported results of human intervention trials [ 24 , 25 ]. Seven studies investigated the effects of hydroxytyrosol [ 24 , 27 , 28 , 33 , 35 , 36 , 62 ], 5 articles reported data on oleuropein [ 26 , 28 , 30 , 31 , 34 ], 5 studies were carried out with olive oil [ 23 , 25 , 29 , 60 , 61 ] and 2 studies with phenolic extracts obtained from Olea europaea leaves [ 21 , 22 ].…”

“…Seven studies investigated the effects of hydroxytyrosol [ 24 , 27 , 28 , 33 , 35 , 36 , 62 ], 5 articles reported data on oleuropein [ 26 , 28 , 30 , 31 , 34 ], 5 studies were carried out with olive oil [ 23 , 25 , 29 , 60 , 61 ] and 2 studies with phenolic extracts obtained from Olea europaea leaves [ 21 , 22 ]. Two investigations reported data on oleacein [ 37 , 63 ] and one study each investigated the effect of hydroxytyrosol-oleate [ 32 ], hydroxytyrosol-3- O -sulphate [ 38 ] and oleocanthal [ 37 ].…”

Antioxidants and Skin Protection

“…In addition, they have developed an interesting approach, using a multistep procedure covering several aspects of antioxidant and related bioactive properties to select the best extract and propose it as an interesting ingredient for the cosmetic industry. Benincasa et al [ 2 ] have used another raw material to develop their study; in this case, they have studied the use of olive oil by-products to obtain a pure compound, hydroxytyrosyl oleate (HtyOle), and then study its antioxidant and regenerative properties on human keratinocytes. The use of by-products from agriculture is really interesting, because it aligns with the Sustainable Development Goals of the United Nations for 2030 [ 3 ] and promotes the use and valorisation of non-previously or low-used materials for high-value applications.…”