Intake Of Virgin Olive Oil Research Articles

Impacts of Cottonseed and Extra Virgin Olive Oil Intake on Plasma Arachidonic Acid and Eicosanoids: A Randomized Controlled Trial

Impacts of Cottonseed and Extra Virgin Olive Oil Intake on Plasma Arachidonic Acid and Eicosanoids: A Randomized Controlled Trial

The Anti-Neuroinflammatory Effect of Extra-Virgin Olive Oil in the Triple Transgenic Mouse Model of Alzheimer’s Disease

Background: Chronic intake of extra virgin olive oil is beneficial for brain health and protects from age-related cognitive decline and dementia, whose most common clinical manifestation is Alzheimer’s disease. Besides the classical pathologic deposits of amyloid beta peptides and phosphorylated tau proteins, another frequent feature of the Alzheimer’s brain is neuroinflammation. Objective: In the current study, we assessed the effect that extra virgin olive oil has on neuroinflammation when administered to a mouse model of the disease. Methods: Triple transgenic mice were randomized to receive a diet enriched with extra virgin olive oil or regular diet for 8 weeks. At the end of this treatment period the expression level of several inflammatory biomarkers was assessed in the central nervous system. Results: Among the 79 biomarkers measured, compared with the control group, mice receiving the extra virgin olive oil had a significant reduction in MIP-2, IL-17E, IL-23, and IL-12p70, but an increase in IL-5. To validate these results, specific ELISA kits were used for each of them. Confirmatory results were obtained for MIP-2, IL-17E, IL-23, and IL-12-p70. No significant differences between the two groups were observed for IL-5. Conclusions: Our results demonstrate that chronic administration of extra virgin olive oil has a potent anti-neuroinflammatory action in a model of Alzheimer’s disease. They provide additional pre-clinical support and novel mechanistic insights for the beneficial effect that this dietary intervention has on brain health and dementia.

Qualitative and quantitative determination of phenols and their metabolites in urine by in-syringe solid-phase extraction and LC–MS/MS analysis for evaluation of virgin olive oil metabolism

To know the bioavailability of virgin olive oil (VOO) phenols and its impact on health, it is necessary to determine the levels of phenols excreted in urine. We present here a novel strategy for in-syringe solid-phase extraction and analysis of the extract by liquid chromatography–tandem mass spectrometry (LC–MS/MS), using ammonium fluoride as ionization agent to enhance sensitivity. This approach allows avoiding additional steps such as solvent evaporation or analytes derivatization. The method can be used with a previous acid hydrolysis for quantitative determination of tyrosol and hydroxytyrosol to estimate metabolized phenols. We tested this application by analysis of a cohort of volunteers (n = 20) after a standardized intake of VOO. Additionally, the method can be used as such for metabolite profiling of phenolic derivatives in urine using LC–MS/MS in high-resolution data-independent acquisition (DIA). Information about the phenolic profile of the consumed VOO and the human metabolism is thus obtained. The proposed approach represents a simple and versatile tool for qualitative and quantitative characterization of VOO phenolic metabolism.

Effects of supplementation with virgin olive oil on hormonal status in half-marathon trained and untrained runners

Several studies have investigated the effects of exercise on hormonal status. Several studies have reported that exercise induce alterations in hormone concentrations. This study focuses on the effects associated to the intake of virgin olive oil, rich in monounsaturated fatty acids (MUFA) on hormonal status in half-marathon athletes. The contents of tocopherols, phenolic compounds, Pigment, flavonoids, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical test and activity of the oil on hydrogen peroxide were determined. The consequence of the consumption of virgin olive oil on hormonal status was studied in healthy male athletes of ages between 19–22 years. The participants were separated into three groups of ten subjects each and reserved under distinct regimes for 10 weeks as follows: Group 1 untrained runners receiving 20 ml of olive oil, Group 2 half-marathon runner performing training routines, 5 days a week while receiving 20 ml of olive oil, Group 3 half-marathon runners performing training routines, 5 days a week unsupplemented with virgin olive oil. Blood samples were taken: one day before endurance training programme, after a 10- week endurance training programme, at the end of the training period, two days before the half-marathon race, and 24 hours after the half-marathon race. Plasma was analyzed for testosterone (T), luteinizing hormone (LH), Follicle Stimulating Hormone (FSH), cortisol (C) and insulin. The results of this study showed that virgin olive oil of Blanquette variety is characterized by high content of tocopherols, phenolic compounds (25.2 ± 0.07 mg/Kg, 485, 46 ± 1.35 mg/Kg), pigments with 79.34.± 0.92 ppm of Total carotenoids, and a high percentage inhibition of the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical and a percentage of hydrogen peroxide (H2O2) inhibition was observed (76.03 ± 0.43% and 86.45±0. 28%, respectively). The consumption of this oil was associated with statistically significant increase of Testosterone in supplemented groups compared with runner of non-supplemented group and sedentary controls. Luteinizing hormone (LH) concentration decreased in runners not supplemented with virgin olive oil compared to group 2 runners and sedentary controls. After a 10-week running training program (before half-marathon race) and immediately after a half-marathon race, cortisol only significantly increased (p<0.001) in runners of group 3; it then demonstrated a tendency toward declining 24 hours after a marathon race. This study found that virgin olive oil supplementation can improve hormonal status in half-marathon athletes. Key words: olive oil, monounsaturated fatty acid, tocopherols, exercise, half-marathon

Metabolomic-Based Studies of the Intake of Virgin Olive Oil: A Comprehensive Review.

Virgin olive oil (VOO) is a high-value product from the Mediterranean diet. Some health and nutritional benefits have been associated with its consumption, not only because of its monounsaturated-rich triacylglycerols but also due to its minor bioactive components. The search for specific metabolites related to VOO consumption may provide valuable information to identify the specific bioactive components and to understand possible molecular and metabolic mechanisms implicated in those health effects. In this regard, metabolomics, considered a key analytical tool in nutritional studies, offers a better understanding of the regulatory functions of food components on human nutrition, well-being, and health. For that reason, the aim of the present review is to summarize the available scientific evidence related to the metabolic effects of VOO or its minor bioactive compounds in human, animal, and in vitro studies using metabolomics approaches.

Synergistic Effect of Squalene and Hydroxytyrosol on Highly Invasive MDA-MB-231 Breast Cancer Cells.

Several studies relate Mediterranean diet and virgin olive oil (VOO) intake with lower risk of several chronic diseases, including breast cancer. Many of them described antitumor properties of isolated minor compounds present in VOO, but beneficial properties of VOO arise from the effects of all its compounds acting together. The aim of the present study was to test the antitumor effects of two minor compounds from VOO (hydroxytyrosol (HT) and squalene (SQ)) on highly metastatic human breast tumor cells (MDA-MB-231) when acting in combination. Both isolated compounds were previously analyzed without showing any antitumoral effect on highly invasive MDA-MB-231 breast cancer cells, but the present results show that HT at 100 µM, combined with different concentrations of SQ, could exert antitumor effects. When they are combined, HT and SQ are able to inhibit cell proliferation, promoting apoptosis and DNA damage in metastatic breast cancer cells. Therefore, our results suggest that the health-promoting properties of VOO may be due, at least in part, to the combined action of these two minor compounds.

Possible Cardio-protective Effect of Olive Oil in Experimentally Induced Hyperthyroidism in Rats

Abstract Background Hyperthyroidism is an endocrine disorder that causes both functional and structural changes in the cardiovascular system. Untreated hyperthyroidism and even persistent subclinical thyroid hyperactivity has been associated with the development of Heart failure by inducing atrial fibrillation, chronic hemodynamic overload, oxidative stress and activation of renin-angiotensin pathway. HF secondary to hyperthyroidism is a reversible cause of cardiomyopathy, which highlights the importance of its prompt diagnosis and treatment. Olive oil with its phenolic compounds are powerful antioxidant that may serve as potential therapeutic agents to reduce cardiovascular hazardous effect of hyperthyroidism and intake of virgin olive oil provides benefits on cardiovascular disease. Aim of the work The aim of the present study is to evaluate the possible cardio-protective effects of olive oil, as a natural antioxidant, in experimentally induced hyperthyroidism in rats. Also, to elucidate the underlying mechanism(s), if any, of its effects. Materials and Methods Animals used were 30 adult male albino rats, which were randomly allocated into three groups. Control group(n = 10): received intraperitoneal (i.p.) injection of the solvent of L-thyroxine daily for 4 consecutive weeks. Hyperthyroid group (n = 10): received i.p. injection of L-thyroxine 100μg/kg daily for 4 consecutive weeks. Olive oil-treated hyperthyroid group (n = 10): received i.p. L-Thyroxine as in group II. By the beginning of the third week, 1 ml/100 g B.W extra virgin olive oil was given daily by gavage for 2 weeks. At the end of the study, the overnight fasted rats were subjected to collection of retroorbital blood samples for determination of T3, T4, TSH serum levels. Rats were then weighed and anaesthetized with thiopental sodium (EIPICO, Egypt), IP (40 mg/kg B.W). Then, ECG was recorded. The heart was then subjected to In vitro study of isolated hearts perfused in langendorff preparation. Hearts chambers were then weighed. Apex of left ventricle was used in histopathological examination. Results The induction of hyperthyroidism was confirmed by T3 and T4 levels that were significantly increased, while TSH was significantly decreased in hyperthyroid group as well as olive oil-treated hyperthyroid group compared to control group. Compared to control group, both hyperthyroid and olive oil-treated hyperthyroid groups showed significant decrease in FBW, FBMI, BW% and BMI%. The absolute weights of RV, LV, WH, as well as, their relative weights RV/BW, LV/BW and WH/BW all were significantly increased. Compared to hyperthyroid group, olive oil-treated hyperthyroid group showed significant decrease in FBW as well as FBMI. The LV/BW and WH/BW were significantly increased. As regard ECG findings, HR, QRS duration and amplitude were significantly increased in both hyperthyroid and olive oil-treated hyperthyroid groups as compared to control rats. In the hyperthyroid group the PR interval was significantly shortened compared to control group, after olive oil-treatment PR interval increased significantly compared to hyperthyroid group, and became insignificant from control group. The baseline values in isolated perfused hearts study showed, significant increase in spontaneous beating rate in both hyperthyroid and olive oil-treated hyperthyroid groups as compared to control group. Hyperthyroid group showed non-significant decrease in TG/unit time and significant decrease in HRT compared to control group Olive oil-treated hyperthyroid group TG/unit time was non-significantly increased compared to control group and significantly increased compared to hyperthyroid group. HRT was the same as hyperthyroid group while. Isoprotrenol infusion showed early toxicity in hyperthyroid group indicated by reduced TG/unit time and HRT compared to control group. Olive oil-treated hyperthyroid group TG/unit time maximal response was significantly increased compared to hyperthyroid group, being non-significant from control group. The hematoxylin and eosin study of the left ventricular cardiac muscle, the hyperthyroid group showed apparent structural changes that were partially reversed by olive oil treatment. Conclusion Olive oil was able to impose partial improvement on cardiac systolic function at baseline condition, also, in response to the beta adrenergic agonist, isoproterenol, even though this improvement did not reach control levels.

May bioactive compounds from the olive fruit improve the postprandial insulin response in healthy adults?

• Virgin olive oil enriched with bioactive compounds from the olive fruit (polyphenols and triterpenic acids), improves postprandial insulin release and peripheral tissue sensitivity. • Matsuda index of insulin sensitivity improves after the intake of bioactive compounds-enriched virgin olive oil. • The insulinogenic index improved after the intake of polyphenol-enriched virgin olive oil. Scope. The postprandial effects of virgin olive oils (VOOs) enriched with phenolic compounds and triterpenes from the olive fruit on plasma glucose and insulin (primary outcomes), and gastrointestinal hormones responses were evaluated in healthy adults. Single doses (30 mL) of three oils were evaluated: optimized polyphenols-rich VOO (OVOO); functional olive oil (FOO): OVOO enriched with triterpene acids; and VOO with low content of polyphenols. Postprandial plasma insulin release was lower after the intake of the FOO compared to VOO, while plasma glucose levels were lower after the intake of the VOO compared to OVOO. Matsuda's index of insulin sensitivity improved after the intake of FOO and OVOO, while the insulinogenic index and gastric inhibitory polypeptide (GIP) tended to improve after the intake of OVOO. The enrichment of VOOs with bioactive compounds from the olive fruit increases its benefits, improving postprandial insulin release and peripheral tissue sensitivity.

Effectiveness of Turmeric and Extra Virgin Olive Oil in the Management of IL 6 and IL 10 in Healthy Mice

Background: Anti-Inflammatory properties of turmeric and extra virgin olive oil have numerous health benefits. They exert and promote anti-inflammatory actions, moreover, each gives benefits that go beyond reducing inflammation.
 Objective: The aim of our study is to evaluate and compare the immunomodulatory effect of each turmeric and extra virgin olive oil (EVOO) alone or in combination.
 Methods: We demonstrated the serum level of pro-inflammatory cytokines IL-6 and IL-10 in healthy male Swiss albino mice (C57BL/6 strain) after oral intake of curcumin and extra virgin olive oil for six weeks by ELISA assay. 
 Results: Our results showed that dietary intake of turmeric and EVOO had a reducing effect on serum IL-6 level and could increase the production of IL-10 level significantly. Inflammatory responses of turmeric and EVOO combination appear to be more effective on health by inhibition of IL 6 and induce IL 10 production. 
 Conclusion: Anti-inflammatory effect of turmeric and EVOO can play an important role in modulating the level of IL 6 and IL-10. Moreover, co-administration of them having a greater anti-inflammatory effect.

Determination of hydroxytyrosol and tyrosol in human urine after intake of extra virgin olive oil produced with an ultrasounds-based technology

Extra virgin olive oil (EVOO) is a known source of antioxidants, such as phenolic compounds, useful in the prevention of non-infectious diseases (atherosclerosis, diabetes, cancer, and other diseases). In the present study, EVOO obtained using an innovative ultrasounds-based technology was found richer in total polyphenols, hydroxytyrosol and tyrosol, than EVOO obtained using a conventional mechanical technology. The urinary excretion in humans of hydroxytyrosol and tyrosol, after the administration of ultrasounds and mechanical EVOOs, respectively, was assessed and compared. The analytes were determined in urine samples, collected for 24 h, of six healthy people (3 men and 3 women, age 22–70 years and body mass index <30 kg/m2) who ingested 20 g of oil for six consecutive days. A commercial refined olive oil was also used in the study to determine the baseline excretion levels of the two metabolites. High correlation coefficients (≥0.9311) were found between the amounts of the analytes ingested daily with EVOOs and those determined in the 24-h urines. The results clearly indicated that the EVOO obtained with the ultrasound process was characterized by the highest concentration of biophenols which were consequently available in greater quantities after ingestion, indicating that it represents a high-quality product containing high levels of beneficial compounds such as biophenols readily assimilable by the human body.

Virgin Olive Oil Phenolic Compounds Modulate the HDL Lipidome in Hypercholesterolaemic Subjects: A Lipidomic Analysis of the VOHF Study.

ScopeThe lipidomic analysis of high‐density lipoprotein (HDL) could be useful to identify new biomarkers of HDL function.Methods and resultsA randomized, controlled, double‐blind, crossover trial (33 hypercholesterolaemic subjects) is performed with a control virgin olive oil (VOO), VOO enriched with its own phenolic compounds (FVOO), or VOO enriched with additional phenolic compounds from thyme (FVOOT) for 3 weeks. HDL lipidomic analyses are performed using the Lipidyzer platform. VOO and FVOO intake increase monounsaturated‐fatty acids (FAs) and decrease saturated and polyunsaturated FAs in triacylglyceride (TAG) species, among others species. In contrast, FVOOT intake does not induce these FAs changes. The decrease in TAG52:3(FA16:0) after VOO intake and the decrease in TAG52:5(FA18:2) after FVOO intake are inversely associated with changes in HDL resistance to oxidation. After FVOO intake, the decrease in TAG54:6(FA18:2) in HDL is inversely associated with changes in HDL cholesterol efflux capacity.ConclusionVOO and FVOO consumption has an impact on the HDL lipidome, in particular TAG species. Although TAGs are minor components of HDL mass, the observed changes in TAG modulated HDL functionality towards a cardioprotective mode. The assessment of the HDL lipidome is a valuable approach to identify and characterize new biomarkers of HDL function.

Metabolic Syndrome Features and Excess Weight Were Inversely Associated with Nut Consumption after 1-Year Follow-Up in the PREDIMED-Plus Study

High nut consumption has been previously associated with decreased prevalence of metabolic syndrome (MetS) regardless of race and dietary patterns. The aim of this study was to assess whether changes in nut consumption over a 1-y follow-up are associated with changes in features of MetS in a middle-aged and older Spanish population at high cardiovascular disease risk. This prospective 1-y follow-up cohort study, conducted in the framework of the PREvención con DIeta MEDiterránea (PREDIMED)-Plus randomized trial, included 5800 men and women (55-75 y old) with overweight/obesity [BMI (in kg/m2) ≥27 and <40] and MetS. Nut consumption (almonds, pistachios, walnuts, and other nuts) was assessed using data from a validated FFQ. The primary outcome was the change from baseline to 1 y in features of MetS [waist circumference (WC), glycemia, HDL cholesterol, triglyceride (TG), and systolic and diastolic blood pressure] and excess weight (body weight and BMI) according to tertiles of change in nut consumption. Secondary outcomes included changes in dietary and lifestyle characteristics. A generalized linear model was used to compare 1-y changes in features of MetS, weight, dietary intakes, and lifestyle characteristics across tertiles of change in nut consumption. As nut consumption increased, between each tertile there was a significant decrease in WC, TG, systolic blood pressure, weight, and BMI (P <0.05), and a significant increase in HDL cholesterol (only in women, P=0.044). The interaction effect between time and group was significant for total energy intake (P <0.001), adherence to the Mediterranean diet (MedDiet) (P <0.001), and nut consumption (P <0.001). Across tertiles of increasing nut consumption there was a significant increase in extra virgin olive oil intake and adherence to the MedDiet; change in energy intake, on the other hand, was inversely related to consumption of nuts. Features of MetS and excess weight were inversely associated with nut consumption after a 1-y follow-up in the PREDIMED-Plus study cohort. This trial was registered at isrctn.com as ISRCTN89898870.

Daily Use of Extra Virgin Olive Oil with High Oleocanthal Concentration Reduced Body Weight, Waist Circumference, Alanine Transaminase, Inflammatory Cytokines and Hepatic Steatosis in Subjects with the Metabolic Syndrome: A 2-Month Intervention Study.

Extra virgin olive oil (EVOO) intake is associated with reduced cardiovascular risk, and its phenolic compound oleocanthal (OC) has anti-oxidant and anti-inflammatory properties. The cardiometabolic effects of EVOO with a high OC concentration have not been fully elucidated. We administered EVOO with a high OC concentration daily to 23 subjects with the metabolic syndrome (MetS) and hepatic steatosis (15 men and 8 women, age: 60 ± 11 years) for 2 months. Anthropometric data, metabolic parameters, hepatic steatosis (by fatty liver index, FLI), abdominal fat distribution (by ultrasound), and pro- and anti-inflammatory cytokines were assessed before and after the intervention. EVOO supplementation was associated with a reduction in body weight, waist circumference, body mass index (BMI), alanine transaminase and FLI, as well as interleukin (IL)-6, IL-17A, tumor necrosis factor-α and IL-1B, while IL-10 increased. Maximum subcutaneous fat thickness (SFT max) also increased, with a concomitant decrease in the ratio of visceral fat layer thickness/SFT max. Correlation analysis revealed positive associations between changes in body weight and BMI and those in SFT max, along with an inverse association between changes in IL-6 and those in SFT max. In conclusion, ingestion of EVOO with a high OC concentration had beneficial effects on metabolic parameters, inflammatory cytokines and abdominal fat distribution in MetS subjects with hepatic steatosis, a category of patients at high cardiometabolic risk.

Hydroxytyrosol as a Promising Ally in the Treatment of Fibromyalgia.

Fibromyalgia (FM) is a chronic and highly disabling syndrome, which is still underdiagnosed, with controversial treatment. Although its aetiology is unknown, a number of studies have pointed to the involvement of altered mitochondrial metabolism, increased oxidative stress and inflammation. The intake of extra virgin olive oil, and particularly of one of its phenolic compounds, hydroxytyrosol (HT), has proven to be protective in terms of redox homeostatic balance and the reduction of inflammation. In this context, using a proteomic approach with nanoscale liquid chromatography coupled to tandem mass spectrometry, the present study analysed: (i) Changes in the proteome of dermal fibroblasts from a patient with FM versus a healthy control, and (ii) the effect of the treatment with a nutritional relevant dose of HT. Our results unveiled that fibroblast from FM show a differential expression in proteins involved in the turnover of extracellular matrix and oxidative metabolism that could explain the inflammatory status of these patients. Moreover, a number of these proteins results normalized by the treatment with HT. In conclusion, our results support that an HT-enriched diet could be highly beneficial in the management of FM.

High-fat but not normal-fat intake of extra virgin olive oil modulates the liver proteome of mice

The metabolic benefits of the Mediterranean diet have been largely attributed to its olive oil content. Whether the ingested fat amount is relevant to these effects is not clear. We thus compared the effects of high-fat and normal-fat intake of extra-virgin olive oil (EVOO) on the liver proteome. Three groups of mice were fed for 12weeks with either normal-fat diets containing either soybean oil (control, C) or EVOO (NO) or a high-fat EVOO diet (HO). Body weight and food intake were measured weekly and serum parameters were analyzed. The liver was processed for data-independent acquisition mass spectrometry-based proteomics. The differentially expressed proteins among the groups were submitted to pathway enrichment analysis. The consumption of HO diet reduced food intake and serum triglycerides, while it preserved body weight gain, adiposity, and glycemia. However, it increased serum cholesterol and liver mass. The proteomic analysis showed 98 altered proteins, which were allocated in 27 significantly enriched pathways. The pathway analysis suggested stimulation of mitochondrial and peroxissomal β-oxidation, and inhibition of lipid synthesis and gluconeogenesis in the HO group. Although the NO group failed to show significant liver proteome alterations, it presented reduced body fat, body weight gain, and serum triglycerides and glucose levels. The data indicate that the intake of the HO diet induced hepatic adjustments, which were partially successful in counteracting the detrimental outcomes of a high-fat feeding. Contrastingly, the NO diet had beneficial effects which were not accompanied by significant modifications on hepatic proteome.

A comparative study of the antiangiogenic activity of hydroxytyrosyl alkyl ethers

The phenolic compound hydroxytyrosol and its derivatives are responsible for some of the health benefits of the intake of virgin olive oil, having shown antiangiogenic properties. In this study, we explored the antiangiogenic potential of six synthetic hydroxytyrosyl alkyl ethers (HT C1, C2, C4, C6, C8 and C12). Our results showed that all compounds affected endothelial cell viability in vitro at low micromolar doses. In addition, compounds HT C1, C2, C4 and C6 inhibited endothelial cell migration and formation of tubular-like structures. In these assays, hydroxytyrosyl hexyl ether (HT C6) exhibited the most potent inhibitory activity in vitro, activating as well apoptosis in endothelial cells. Furthermore, the antiangiogenic activity of HT C6 was confirmed in vivo in the chick chorioallantoic membrane assay. Hence, we present hydroxytyrosol synthetic derivative HT C6 as a new antiangiogenic compound and as a good candidate for an antiangiogenic drug in the treatment of angiogenesis-dependent diseases.

Effect of olive ripening degree on the antidiabetic potential of biophenols-rich extracts of Brava Gallega virgin olive oils

The diet management is imperative to anticipate risk factors that favour the development of diseases; indeed, the intake of virgin olive oil could be an alternative natural source of α-glucosidase enzyme inhibitors, which delay the digestion rate of carbohydrates. Consequently, the impact of diabetes mellitus (DM) could be diminished.Extra Virgin Olive Oils (EVOO) were elaborated from Galician autochthonous variety ‘Brava Gallega’ with olives selected at three different degree of ripeness (ripening index, RI: 1.4, 3.0, 5.5) in order to assess the effect of maturation on overall chemical composition, sensory quality, and enzyme inhibition.The phenolic profile of the EVOOs determined by LC-ESI-IT-MS exhibited quantitative differences as ripening advanced; for example oleocanthal, tyrosol, luteolin and apigenin concentrations were higher in the overripe olive oil (RI 5.5). Anyway, the phenolic extracts (from every tested RI) were more active than acarbose. In particular, those obtained from the most mature olives displayed the most powerful inhibitory activity (IC50 value of 143 µg of dry extract/mL). In addition, the significant effect of these compounds (i.e. luteolin, apigenin, tyrosol and oleocanthal) on the inhibitory activity of the olive oil extracts was demonstrated. Our results suggest that, regardless of RI, the inhibitory activity of ‘Brava Gallega’ olive oils could represent a valuable strategy for reinforcing the health claim of olive oil for phenolic compounds.

Pharmacokinetics and bioavailability of hydroxytyrosol are dependent on the food matrix in humans.

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. A double-blind study was performed including 20 volunteers who ingested 5mg of hydroxytyrosol through diverse food matrices, to discover the influence on pharmacokinetics and bioavailability of HT metabolites (hydroxytyrosol acetate, 3,4-dihydroxyphenylacetic acid (DOPAC), tyrosol, and homovanillic alcohol) of the distinct matrices by UHPLC-ESI-QqQ-MS/MS. The 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 30min of oral intake (3.79ng/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 0.33µg/mg creatinine, respectively) compared with basal urine, whereas hydroxytyrosol metabolites showed no significant changes. No differences were found between men and women. The 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 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.

Efficient extraction and sensitive LC-MS quantification of hydroxytyrosol in wine, oil and plasma

Hydroxytyrosol (HT) possesses significant biological activity. However, the methodologies for its quantification always suffered from low sensitivity, intricate treatment and high sample consumption. Here, we presented the very first attempt for specific extraction of HT through cis-diol recognition mechanism. By using easily prepared zirconia as dispersive solid phase extraction medium, HT from small amount of wine (10 μL), oil (20 mg) and plasma (100 μL) was efficiently purified within ten minutes. Coupled with LC-MS/MS analysis, the method limit of detection (LOD) could reach 1 ng/mL in wine, 0.5 μg/kg in oil and 0.1 ng/mL in plasma. Profited by this superior method, HT analysis was successfully performed in diverse wine and oil products as well as human plasma samples after intake of extra virgin olive oil. In addition, we further confirmed the endogenous HT was undetectable from routine human plasma even after upgrading the detection sensitivity through post isonicotinoyl chloride derivatization.

Effects of Virgin Olive Oil and Phenol-Enriched Virgin Olive Oils on Lipoprotein Atherogenicity.

The atherogenicity of low-density lipoprotein (LDL) and triglyceride-rich lipoproteins (TRLs) may be more significant than LDL cholesterol levels. Clinical trials which have led to increased high-density lipoprotein (HDL) cholesterol have not always seen reductions in cardiovascular disease (CVD). Furthermore, genetic variants predisposing individuals to high HDL cholesterol are not associated with a lower risk of suffering a coronary event, and therefore HDL functionality is considered to be the most relevant aspect. Virgin olive oil (VOO) is thought to play a protective role against CVD. This review describes the effects of VOO and phenol-enriched VOOs on lipoprotein atherogenicity and HDL atheroprotective properties. The studies have demonstrated a decrease in LDL atherogenicity and an increase in the HDL-mediated macrophage cholesterol efflux capacity, HDL antioxidant activity, and HDL anti-inflammatory characteristics after various VOO interventions. Moreover, the expression of cholesterol efflux-related genes was enhanced after exposure to phenol-enriched VOOs in both post-prandial and sustained trials. Improvements in HDL antioxidant properties were also observed after VOO and phenol-enriched VOO interventions. Furthermore, some studies have demonstrated improved characteristics of TRL atherogenicity under postprandial conditions after VOO intake. Large-scale, long-term randomized clinical trials, and Mendelian analyses which assess the lipoprotein state and properties, are required to confirm these results.