Health-promoting phenolic compounds in extra virgin olive oil: an integrated study of their concentration and bioavailability

[eng] The health promoting attributes associated with following a traditional Mediterranean diet have been reviewed extensively. The principal source of dietary fat in the Mediterranean diet is Extra virgin olive oil (EVOO) that contribute significantly to the superior health profile observed in Mediterranean populations. Between its minors compounds, EVOO contains at least 30 phenolic compounds (PCs) and has been classified according to their chemical structure into the following main classes: phenolic acids, lignans, flavonoids, phenolic alcohols, secoiridoids (SEC). Regarding this last group, these compounds are responsible for the sensory features of EVOO, mainly the bitter and pungent mouthfeel. Oleocanthal (OLC) and oleacein (OLEA) appear the main compounds responsible for the mouthfeel perceptions, respectively. Moreover, they are the most studied and best-known components in terms of health protecting activities. In this sense, the potential protective role exerted by SECs from EVOO in cancer, cardiovascular, neurodegenerative, aging‐related, and immunoinflammatory diseases has been studied. The data obtained so far has clearly shown that SECs has proven biological activity, including antioxidant and antimicrobial properties, anti-inflammatory effects, anticancer properties and neuro- protective effects, among others. The phenolic concentration and composition of EVOO together with the degree to which these components are absorbed and metabolized are essential in determining the health effects associated with such compounds. Several factors have been shown to affect the concentration of PCs in EVOO and these include olive fruit cultivar and variety, region of growth, agricultural cultivation techniques, maturity at harvest, processing, and storage. In this thesis the study of the main factors affecting the PCs concentration is covered. Regarding its bioavailability after EVOO dietary intake has been a topic of increasing research in recent years. Bioavailability is a complex process involving several different stages that include liberation, absorption, distribution, metabolism and elimination phases. For polyphenols, this principally involves the following digestive processes: i) release of polyphenols from the food matrix; ii) changes in PCs during gastric/small-intestinal digestion; iii) cellular uptake of aglycons and some conjugated polyphenols by enterocytes; iv) microbiological fermentation of nonabsorbed polyphenols or those re-excreted via bile or the pancreas to yield additional metabolites, v) phase I/II enzyme modifications that occur upon uptake in the small intestine and/or colon; vi) transport in the bloodstream and subsequent tissue redistribution; and vii) excretion via the kidney or re-excretion into the gut via bile and pancreatic juices. Since many in vitro, in situ, in vivo and clinical studies, have demonstrated the protective effect of SECs, in this thesis we set out to evaluate the intestinal absorption and metabolism of OLC and OLEA for a better understanding of the biological effects attributed to these compounds. In addition, a tissue distribution of OLC and OLEA and its metabolites also was study after the oral administration of enriched refined olive oil. Target tissues likes as brain, hearth, lungs, among other were evaluated to determine the biological concentrations usually achieved when following a Mediterranean diet

Traceability, Authenticity and Sustainability of Cocoa and Chocolate Products: a Challenge for the Chocolate Industry

Cocoa beans, the seeds of the tree Theobroma cacao L., are the key raw material for chocolate production that implies an extensive post-harvest process. Chocolate properties can vary depending on cocoa origin, composition and manufacturing procedure, which will give unique sensory properties to the final product. On the other hand, the high global consumption of cocoa products, long recognized as a major source of dietary polyphenols with important health benefits, has increased interest in tracking the geographical origin of cocoa and authenticating chocolate to guarantee product quality and reveal possible commercial fraud. However, the sustainable production of high-quality cocoa is still far from reality, and the cocoa sector continues to face many challenges in this field. This review provides an update on the progress toward the authenticity, traceability and sustainability of cocoa products, issues that chocolate producers still need to resolve

Insights into the Binding of Dietary Phenolic Compounds to Human Serum Albumin and Food-Drug Interactions

The distribution of drugs and dietary phenolic compounds in the systemic circulation depends on, among other factors, unspecific/specific reversible binding to plasma proteins such as human serum albumin (HSA). Phenolic substances, present in plant-derived feeds, foods, beverages, herbal medicines, and dietary supplements, are of great interest due to their biological activity. Recently, considerable research has been directed at the formation of phenol-HSA complexes, focusing above all on structure-affinity relationships. The nucleophilicity and planarity of molecules can be altered by the number and position of hydroxyl groups on the aromatic ring and by hydrogenation. Binding affinities towards HSA may also differ between phenolic compounds in their native form and conjugates derived from phase II reactions. On the other hand, food-drug interactions may increase the concentration of free drugs in the blood, affecting their transport and/or disposition and in some cases provoking adverse or toxic effects. This is caused mainly by a decrease in drug binding affinities for HSA in the presence of flavonoids. Accordingly, to avoid the side effects arising from changes in plasma protein binding, the intake of flavonoid-rich food and beverages should be taken into consideration when treating certain pathologies

LC-ESI-LTQ-Orbitrap-MS for Profiling the Distribution of Oleacein and Its Metabolites in Rat Tissues

The purpose of this work was to study the distribution of oleacein (OLEA) and its metabolites in rat plasma and different tissues, namely brain, heart, kidney, liver, lung, small intestine, spleen, stomach, skin, and thyroid, following the acute intake of a refined olive oil containing 0.3 mg/mL of OLEA. For this purpose, a distribution kinetics study was carried out. The plasma and tissues were collected at 1, 2, and 4.5 h after the intervention, and analyzed by LC-ESI-LTQ-Orbitrap-MS. Unmetabolized OLEA was detected in the stomach, small intestine, liver, plasma and, most notably, the heart. This finding may be useful for the development of new applications of OLEA for cardiovascular disease prevention. Noteworthy are also the high levels of hydroxytyrosol (OH-TY) and OLEA + CH3 found in the small intestine, liver, and plasma, and the detection of nine OLEA metabolites, five of them arising from conjugation reactions. Liver, heart, spleen, and lungs were the target tissues where the metabolites were most distributed. However, it is important to note that OH-TY, in our experimental conditions, was not detected in any target tissue (heart, spleen, thyroids, lungs, brain, and skin). These results shed further light on the metabolism and tissue distribution of OLEA and contribute to understanding the mechanisms underlying its effect in human health. Keywords: biotransformation, extra virgin olive oil, hydroxytyrosol, phenolic compound, secoiridoi

Predicting the effects of in-vitro digestion in the bioactivity and bioaccessibility of antioxidant compounds extracted from chestnut shells by supercritical fluid extraction - A metabolomic approach

Chestnut (Castanea sativa) shells (CS) are an undervalued antioxidant-rich by-product. This study explores the impact of in-vitro digestion on the bioaccessibility, bioactivity, and metabolic profile of CS extract prepared by Supercritical Fluid Extraction, aiming its valorization for nutraceutical applications. The results demonstrated significantly (p <0.05) lower phenolic concentrations retained after digestion (38.57 µg gallic acid equivalents/ mg dry weight (DW)), reaching 30% of bioaccessibility. The CS extract showed antioxidant/antiradical, hypoglycemic, and neuroprotective properties after in-vitro digestion, along with upmodulating effects on antioxidant enzymes activities and protection against lipid peroxidation. The metabolic profile screened by LC-ESI-LTQ- Orbitrap-MS proved the biotransformation of complex phenolic acids, flavonoids, and tannins present in the undigested extract (45.78 µg/mg DW of total phenolic concentration) into hydroxybenzoic, phenylpropanoic, and phenylacetic acids upon digestion (35.54 µg/mg DW). These findings sustain the valorization of CS extract as a promising nutraceutical ingredient, delivering polyphenols with proven bioactivity even after in-vitro digestion.</p

The Effectiveness of Extra Virgin Olive Oil and the Traditional Brazilian Diet in Reducing the Inflammatory Profile of Individuals with Severe Obesity: A Randomized Clinical Trial

We analyzed the effectiveness of two nutritional interventions alone and together, EVOO and the DieTBra, on the inflammatory profile of severely obese individuals. This study was an RCT with 149 individuals aged from 18 to 65 years, with a body mass index ≥ 35 kg/m2, randomized into three intervention groups: (1) 52 mL/day of EVOO (n = 50); (2) DieTBra (n = 49); and (3) DieTBra plus 52 mL/day of EVOO (DieTBra + EVOO, n = 50). The primary outcomes we measured were the-neutrophil-to-lymphocyte ratio (NLR) and the secondary outcomes we measured were the lymphocyte-to-monocyte ratio (LMR); leukocytes; and C reactive protein (CRP). After 12 weeks of intervention, DieTBra + EVOO significantly reduced the total leucocytes (p = 0.037) and LMR (p = 0.008). No statistically significant differences were found for the NLR in neither the intra-group and inter-group analyses, although a slight reduction was found in the DieTBra group (-0.22 ± 1.87). We observed reductions in the total leukocytes and LMR in the three groups, though without statistical difference between groups. In conclusion, nutritional intervention with DietBra + EVOO promotes a significant reduction in inflammatory biomarkers, namely leukocytes and LMR. CRP was reduced in EVOO and DieTBra groups and NLR reduced in the DieTBra group. This study was registered at ClinicalTrials.gov under NCT02463435. Keywords: diet; inflammation; leukocytes; lymphocyte; monocytes; nutritional intervention; olive oil; severe obesity

Absorption and Intestinal Metabolic Profile of Oleocanthal in Rats

Oleocanthal (OLC), a phenolic compound of extra virgin olive oil (EVOO), has emerged as a potential therapeutic agent against a variety of diseases due to its anti-inflammatory activity. The aim of the present study is to explore its in vivo intestinal absorption and metabolism. An in situ perfusion technique in rats was used, involving simultaneous sampling from the luminal perfusate and mesenteric blood. Samples were analysed by UHPLC-MS-MS for the presence of oleocanthal (OLC) and its metabolites. OLC was mostly metabolized by phase I metabolism, undergoing hydration, hydrogenation and hydroxylation. Phase II reactions (glucuronidation of hydrogenated OLC and hydrated metabolites) were observed in plasma samples. OLC was poorly absorbed in the intestine, as indicated by the low effective permeability coefficient (2.23 ± 3.16 × 10-5 cm/s) and apparent permeability coefficient (4.12 ± 2.33 × 10-6 cm/s) obtained relative to the values of the highly permeable reference compound levofloxacin (LEV). The extent of OLC absorption reflected by the area under the mesenteric blood-time curve normalized by the inlet concentration (AUC) was also lower than that of LEV (0.25 ± 0.04 vs. 0.64 ± 0.03, respectively). These results, together with the observed intestinal metabolism, suggest that OLC has a moderate-to-low oral absorption; but higher levels of OLC are expected to reach human plasma vs. rat plasma

Reply to 'Comment on López-Yerena et al. 'Absorption and intestinal metabolic profile of oleocanthal in rats' Pharmaceutics 2020, 12, 134'

Recently, in February 2020, we published a study exploring the intestinal absorption and metabolism of oleocanthal (OLC) in rats. A single-pass intestinal perfusion technique (SPIP) was used, involving simultaneous sampling from the luminal perfusate and mesenteric blood. Later, comments on our published paper were released, requesting clarification of specific data. In this detailed reply, we hope to have addressed and clarified all the concerns of A. Kaddoumi and K. El Sayed and that the scientific community will benefit from both the study and the comments it has generated

Oleacein Intestinal Permeation and Metabolism in Rats Using an In Situ Perfusion Technique

Oleacein (OLEA) is one of the most important phenolic compounds in extra virgin olive oil in terms of concentration and health-promoting properties, yet there are insufficient data on its absorption and metabolism. Several non-human models have been developed to assess the intestinal permeability of drugs, among them, single-pass intestinal perfusion (SPIP), which is commonly used to investigate the trans-membrane transport of drugs in situ. In this study, the SPIP model and simultaneous luminal blood sampling were used to study the absorption and metabolism of OLEA in rats. Samples of intestinal fluid and mesenteric blood were taken at different times and the ileum segment was excised at the end of the experiment for analysis by LC-ESI-LTQ-Orbitrap-MS. OLEA was mostly metabolized by phase I reactions, undergoing hydrolysis and oxidation, and metabolite levels were much higher in the plasma than in the lumen. The large number of metabolites identified and their relatively high abundance indicates an important intestinal first-pass effect during absorption. According to the results, OLEA is well absorbed in the intestine, with an intestinal permeability similar to that of the highly permeable model compound naproxen. No significant differences were found in the percentage of absorbed OLEA and naproxen (48.98 ± 12.27% and 43.96 ± 7.58%, respectively)

NMR Spectroscopy: A powerful tool for the analysis of polyphenols in extra virgin olive oil

Extra virgin olive oil (EVOO), a key component of the Mediterranean Diet, has aroused interest in recent years due to its health properties. Nuclear magnetic resonance (NMR) spectroscopy is an appropriate tool for the accurate quantification of minor compounds in complex food matrices, such as polyphenols in olive oil. Flavonoids, lignans, secoiridoids and phenolic acids and alcohols in EVOO have been identified and quantified by NMR. This review provides an overview of the major developments in the structural elucidation of polyphenol compounds in EVOO