Biological Relevance of Extra Virgin Olive Oil Polyphenols Metabolites

Abstract

Extra virgin olive oil (EVOO) polyphenols beneficial effects have widely been debated throughout the last three decades, with greater attention to hydroxytyrosol and tyrosol, which are by far the most studied. The main concern about the evaluation of EVOO phenols activities in vitro and in vivo is that the absorption and metabolism of these compounds once ingested lead to the production of different metabolites in the human body. EVOO phenols in the ingested forms are less concentrated in human tissues than their glucuronide, sulfate and methyl metabolites; on the other hand, metabolites may undergo deconjugation before entering the cells and thus act as free forms or may be reformed inside the cells so acting as conjugated forms. In most in vitro studies the presence of methyl/sulfate/glucuronide functional groups does not seem to inhibit biological activity. Parent compounds and metabolites have been shown to reach tissue concentrations useful to exert beneficial effects others than antioxidant and scavenging properties, by modulating intracellular signaling and improving cellular response to oxidative stress and pro-inflammatory stimuli. This review aims to give an overview on the reported evidence of the positive effects exerted by the main EVOO polyphenols metabolites in comparison with the parent compounds.

Extra Virgin Olive Oil Polyphenols: Modulation of Cellular Pathways Related to Oxidant Species and Inflammation in Aging

“…Polyphenols compose the hydrophilic fraction of EVOO, which is only a small portion with respect to lipophilic compounds [19,20] (Figure 1). The phenolic fraction consists of a few tens of compounds, although in reality, not all of them are found together in every EVOO [21].…”

“…The phenolic fraction consists of a few tens of compounds, although in reality, not all of them are found together in every EVOO [21]. All these compounds pertain to different chemical subclasses, are present in a broad range of concentrations [20], and basically belong to six subclasses: Secoiridoids (dialdehydic forms of decarboxymethyl elenolic acid linked to tyrosol (Tyr) or hydroxytyrosol (HT), oleacein, oleuropein, and oleocanthal) [22,23], phenylethanoids (HT and Tyr) [22], flavonoids (apigenin and luteolin) [23], phenolic acids (for instance, ferulic acid, caffeic acid, and gallic acid) [23], hydroxy-isocromans (1-(39-methoxy-49-hydroxy)phenyl-6,7-dihydroxy-isochroman and 1-phenyl-6,7-dihydroxyiso -chroman) [24], and lignans ((+)-1-acetoxypinoresinol and (+)-1-pinoresinol) [25]. Most of the studies concerning the bioactivity of these polyphenols aimed to show the numerous properties of two phenols, HT and Tyr, which are the most concentrated in EVOO together with elenolic esters oleocanthal, oleuropein-, and ligstroside-aglycons [20,26].…”

Antioxidant Activity of Polyphenolic Plant Extracts

“…As mentioned hydroxytyrosol is present in high concentration in olive oil which also contains other potent polyphenolic antioxidants such as oleuropein, tyrosol, coumaric acid, caffeic acid, vanillic acid, ferulic acid, kaempferol, and quercetin [10]. Aprile et al [11] assessed for the first time the antioxidant activity and the total polyphenolic content of olive fruits from the olive tree "Cellina di Nardò" (CdN), one of the most widespread cultivars in Southern Italy.…”

A Social Analysis of the Olive Oil Sector: The Role of Family Business

“…Furthermore, a special focus is dedicated to the organic product [71,72]. Among respondents prevails the idea that consumers give a great importance to natural resources (No.…”