Hydroxytyrosol is one of the main phenolic components of olive oil. It is present in the fruit and leaf of the olive (Olea europaea L.). During the past decades, it has been well documented that this phenolic compound has health benefits and a protective action has been found in preclinical studies against several diseases. Here, we review its bioavailability in human beings and several assays showing significant results related with cardiovascular diseases, cancer, and acquired immunodeficiency syndrome (AIDS). Mechanisms of action include potent anti-oxidant and anti-inflammatory effects, among others. The importance of hydroxytyrosol in protection of low-density lipoproteins and consequently its implication in the reduction of cardiovascular disease risk has been highlighted by the European Food Safety Authority, concluding that 5 mg of hydroxytyrosol and its derivatives should be consumed daily to reach this effect at physiological level. We discuss the potential uses of this compound in supplements, nutraceutic foods, or topical formulations in the disease risk reduction. Finally, we conclude that more studies are needed to sustain or reject many other health claims not yet fully documented and to validate these newly available hydroxytyrosol-based products, because it seems to be a good candidate to reduce the risk of diseases mentioned.

Our results suggest that different dosages of HT, HTA, and DOPAC do not provide a linear, dose-dependent plasma concentration or excretion in urine, both of which can be affected by the saturation of first-phase metabolic processes and intestinal transporters.

Purpose Several studies have demonstrated the properties of hydroxytyrosol, a phenolic compound present in olive oils and olives with a well-characterized impact on human health. Nevertheless, some knowledge gaps remain on its bioavailability and metabolism; overall concerning to the real rate per cent of absorption and biovailability of dietary hydroxytyrosol and the influence of the dietary food-containing hydroxytyrosol on it.Methods A double-blind study was performed including 20 volunteers who ingested 5 mg of hydroxytyrosol through diverse food matrices, to discover the influence on pharmacokinetics and bioavailability of HT metabolites (hydroxytyrosol acetate, 3,4dihydroxyphenylacetic acid (DOPAC), tyrosol, and homovanillic alcohol) of the distinct matrices by UHPLC-ESI-QqQ-MS/MS. ResultsThe HT pharmacokinetics after consumption of different food matrices was strongly dependent on the food matrix. In this aspect, the intake of extra virgin olive exhibited significantly higher plasma concentrations after 30 minutes of oral intake (3.79 ng/mL) relative to the control. Regarding the hydroxytyrosol bioavailability, the intake of extra virgin olive oil, as well as fortified refined olive, flax, and grapeseed oils provided significantly higher urinary contents (0.86, 0.63, 0.55, and 0.33 µg/mg creatinine, respectively) compared with basal urine, whereas hydroxytyrosol metabolites showed no significant changes. No differences were found between men and women. ConclusionsThe metabolic profile of hydroxytyrosol is influenced by the food matrix in which is incorporated, with the oily nature for the final bioavailability being relevant. Extra virgin olive oil was identified as the best matrix for this compound. The results described 3 contribute to the understanding of the relevance of the food matrices for the final absorption of hydroxytyrosol and hence, the achievement of the highest health protection potential.

Lipophenols have been stressed as an emerging class of functional compounds. However, little is known about their diversity. Thus, this study is aimed at developing a new method for the extraction, cleanup, and ultrahigh-performance liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (UHPLC-ESI-QqQ-MS/MS)-based analysis of the lipophenols derived from hydroxytyrosol (HT): α-linolenic (HT-ALA), linoleic acid (HT-LA), and oleic acid (HT-OA). The method validated provides reliable analytical data and practical applications. It was applied to an array of oily (extra virgin olive oil, refined olive oil, flaxseed oil, grapeseed oil, and margarine) and aqueous (pineapple juice) matrices, nonfortified and fortified with HT. Also, the present work reported the formation of fatty acid esters of HT (HT-FAs) that seem to be closely dependent on the fatty acid profile of the food matrix, encouraging the further exploration of the theoretical basis for the generation of HT-FAs, as well as their contribution to the healthy attributions of plant-based foods.

Water pollution by dyes is a huge environmental problem; there is a necessity to produce new decolorization methods that are effective, cost-attractive, and acceptable in industrial use. Magnetic cyclodextrin polymers offer the advantage of easy separation from the dye solution. In this work, the β-CD-EPI-magnetic (β-cyclodextrin-epichlorohydrin) polymer was synthesized, characterized, and tested for removal of the azo dye Direct Red 83:1 from water, and the fraction of non-adsorbed dye was degraded by an advanced oxidation process. The polymer was characterized in terms of the particle size distribution and surface morphology (FE-SEM), elemental analysis (EA), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), infrared spectrophotometry (IR), and X-ray powder diffraction (XRD). The reported results hint that 0.5 g and pH 5.0 were the best conditions to carry out both kinetic and isotherm models. A 30 min contact time was needed to reach equilibrium with a qmax of 32.0 mg/g. The results indicated that the pseudo-second-order and intraparticle diffusion models were involved in the assembly of Direct Red 83:1 onto the magnetic adsorbent. Regarding the isotherms discussed, the Freundlich model correctly reproduced the experimental data so that adsorption was confirmed to take place onto heterogeneous surfaces. The calculation of the thermodynamic parameters further demonstrates the spontaneous character of the adsorption phenomena (ΔG° = −27,556.9 J/mol) and endothermic phenomena (ΔH° = 8757.1 J/mol) at 25 °C. Furthermore, a good reusability of the polymer was evidenced after six cycles of regeneration, with a negligible decline in the adsorption extent (10%) regarding its initial capacity. Finally, the residual dye in solution after treatment with magnetic adsorbents was degraded by using an advanced oxidation process (AOP) with pulsed light and hydrogen peroxide (343 mg/L); >90% of the dye was degraded after receiving a fluence of 118 J/cm2; the discoloration followed a pseudo first-order kinetics where the degradation rate was 0.0196 cm2/J. The newly synthesized β-CD-EPI-magnetic polymer exhibited good adsorption properties and separability from water which, when complemented with a pulsed light-AOP, may offer a good alternative to remove dyes such as Direct Red 83:1 from water. It allows for the reuse of both the polymer and the dye in the dyeing process.