Sara Fernández-Castillejo

Olive oil polyphenols enhance the expression of cholesterol efflux related genes in vivo in humans. A randomized controlled trial

Both oleic acid and polyphenols have been shown to increase high-density lipoprotein (HDL) cholesterol and to protect HDL from oxidation, a phenomenon associated with a low cholesterol efflux from cells. Our goal was to determine whether polyphenols from olive oil could exert an in vivo nutrigenomic effect on genes related to cholesterol efflux in humans. In a randomized, controlled, cross-over trial, 13 pre/hypertensive patients were assigned 30 ml of two similar olive oils with high (961 mg/kg) and moderate (289 mg/kg) polyphenol content. We found an increase in ATP binding cassette transporter-A1, scavenger receptor class B type 1, peroxisome proliferator-activated receptor (PPAR)BP, PPARα, PPARγ, PPARδ and CD36 gene expression in white blood cells at postprandial after high polyphenol olive oil when compared with moderate polyphenol olive oil intervention (P<.017), with COX-1 reaching borderline significance (P=.024). Linear regression analyses showed that changes in gene expression were related to a decrease in oxidized low-density lipoproteins and with an increase in oxygen radical absorbance capacity and olive oil polyphenols (P<.05). Our results indicate a significant role of olive oil polyphenols in the up-regulation of genes involved in the cholesterol efflux from cells to HDL in vivo in humans. These results are in agreement with previous ones concerning the fact that benefits associated with polyphenol-rich olive oil consumption on cardiovascular risk could be mediated through an in vivo nutrigenomic effect in humans.

Effects of functional olive oil enriched with its own phenolic compounds on endothelial function in hypertensive patients. A randomised controlled trial

UNLABELLED The additional health-promoting properties of functional virgin olive oil (FVOO) enriched with its own phenolic compounds (OOPC) versus the parental virgin olive oil (VOO) must be tested in appropriate human clinical trials. Our aim was to assess the effects of FVOO on endothelial function in hypertensive patients. Thirteen pre- and stage-1 hypertensive patients received a single dose of 30 mL of FVOO (OOPC=961 mg/kg) or VOO (OOPC=289 mg/kg) in a postprandial randomised, double blind, crossover trial. Endothelial function, measured as ischemic reactive hyperemia (IRH) and related biomarkers, were followed for 5h after consumption. Compared with VOO, FVOO increased IRH (P<0.05) and plasma Cmax of hydroxytyrosol sulphate, a metabolite of OOPC 2h postprandial (P=0.05). After FVOO ingestion, oxidised LDL decreased (P=0.010) in an inverse relationship with IRH AUC values (P=0.01). FVOO provided more benefits on endothelial function than a standard natural virgin olive oil in pre- and hypertensive patients. TRIAL REGISTRATION isrctn.org. Identifier ISRCTN03450153.

Olive Oil Polyphenols Enhance High-Density Lipoprotein Function in Humans A Randomized Controlled Trial

Objective— Olive oil polyphenols have shown beneficial properties against cardiovascular risk factors. Their consumption has been associated with higher cholesterol content in high-density lipoproteins (HDL). However, data on polyphenol effects on HDL quality are scarce. We, therefore, assessed whether polyphenol-rich olive oil consumption could enhance the HDL main function, its cholesterol efflux capacity, and some of its quality-related properties, such HDL polyphenol content, size, and composition. Approach and Results— A randomized, crossover, controlled trial with 47 healthy European male volunteers was performed. Participants ingested 25 mL/d of polyphenol-poor (2.7 mg/kg) or polyphenol-rich (366 mg/kg) raw olive oil in 3-week intervention periods, preceded by 2-week washout periods. HDL cholesterol efflux capacity significantly improved after polyphenol-rich intervention versus the polyphenol-poor one (+3.05% and −2.34%, respectively; P=0.042). Incorporation of olive oil polyphenol biological metabolites to HDL, as well as large HDL (HDL2) levels, was higher after the polyphenol-rich olive oil intervention, compared with the polyphenol-poor one. Small HDL (HDL3) levels decreased, the HDL core became triglyceride-poor, and HDL fluidity increased after the polyphenol-rich intervention. Conclusions— Olive oil polyphenols promote the main HDL antiatherogenic function, its cholesterol efflux capacity. These polyphenols increased HDL size, promoted a greater HDL stability reflected as a triglyceride-poor core, and enhanced the HDL oxidative status, through an increase in the olive oil polyphenol metabolites content in the lipoprotein. Our results provide for the first time a first-level evidence of an enhancement in HDL function by polyphenol-rich olive oil.

Olive Oil Polyphenols Decrease LDL Concentrations and LDL Atherogenicity in Men in a Randomized Controlled Trial

BACKGROUND Olive oil polyphenols have shown protective effects on cardiovascular risk factors. Their consumption decreased oxidative stress biomarkers and improved some features of the lipid profile. However, their effects on LDL concentrations in plasma and LDL atherogenicity have not yet been elucidated. OBJECTIVE Our objective was to assess whether the consumption of olive oil polyphenols could decrease LDL concentrations [measured as apolipoprotein B-100 (apo B-100) concentrations and the total number of LDL particles] and atherogenicity (the number of small LDL particles and LDL oxidizability) in humans. METHODS The study was a randomized, cross-over controlled trial in 25 healthy European men, aged 20-59 y, in the context of the EUROLIVE (Effect of Olive Oil Consumption on Oxidative Damage in European Populations) study. Volunteers ingested 25 mL/d raw low-polyphenol-content olive oil (LPCOO; 366 mg/kg) or high-polyphenol-content olive oil (HPCOO; 2.7 mg/kg) for 3 wk. Interventions were preceded by 2-wk washout periods. Effects of olive oil polyphenols on plasma LDL concentrations and atherogenicity were determined in the sample of 25 men. Effects on lipoprotein lipase (LPL) gene expression were assessed in another sample of 18 men from the EUROLIVE study. RESULTS Plasma apo B-100 concentrations and the number of total and small LDL particles decreased (mean ± SD: by 5.94% ± 16.6%, 11.9% ± 12.0%, and 15.3% ± 35.1%, respectively) from baseline after the HPCOO intervention. These changes differed significantly from those after the LPCOO intervention, which resulted in significant increases of 6.39% ± 16.6%, 4.73% ± 22.0%, and 13.6% ± 36.4% from baseline (P < 0.03). LDL oxidation lag time increased by 5.0% ± 10.3% from baseline after the HPCOO intervention, which was significantly different only relative to preintervention values (P = 0.038). LPL gene expression tended to increase by 26% from baseline after the HPCOO intervention (P = 0.08) and did not change after the LPCOO intervention. CONCLUSION The consumption of olive oil polyphenols decreased plasma LDL concentrations and LDL atherogenicity in healthy young men. This trial was registered at www.controlled-trials.com as ISRCTN09220811.

Olive Oil Polyphenols Enhance High-Density Lipoprotein Function in Humans

Objective— Olive oil polyphenols have shown beneficial properties against cardiovascular risk factors. Their consumption has been associated with higher cholesterol content in high-density lipoproteins (HDL). However, data on polyphenol effects on HDL quality are scarce. We, therefore, assessed whether polyphenol-rich olive oil consumption could enhance the HDL main function, its cholesterol efflux capacity, and some of its quality-related properties, such HDL polyphenol content, size, and composition. Approach and Results— A randomized, crossover, controlled trial with 47 healthy European male volunteers was performed. Participants ingested 25 mL/d of polyphenol-poor (2.7 mg/kg) or polyphenol-rich (366 mg/kg) raw olive oil in 3-week intervention periods, preceded by 2-week washout periods. HDL cholesterol efflux capacity significantly improved after polyphenol-rich intervention versus the polyphenol-poor one (+3.05% and −2.34%, respectively; P=0.042). Incorporation of olive oil polyphenol biological metabolites to HDL, as well as large HDL (HDL2) levels, was higher after the polyphenol-rich olive oil intervention, compared with the polyphenol-poor one. Small HDL (HDL3) levels decreased, the HDL core became triglyceride-poor, and HDL fluidity increased after the polyphenol-rich intervention. Conclusions— Olive oil polyphenols promote the main HDL antiatherogenic function, its cholesterol efflux capacity. These polyphenols increased HDL size, promoted a greater HDL stability reflected as a triglyceride-poor core, and enhanced the HDL oxidative status, through an increase in the olive oil polyphenol metabolites content in the lipoprotein. Our results provide for the first time a first-level evidence of an enhancement in HDL function by polyphenol-rich olive oil.

Protective effect of hydroxytyrosol and its predominant plasmatic human metabolites against endothelial dysfunction in human aortic endothelial cells.

SCOPE Hydroxytyrosol (HT) is the major phenolic compound in virgin olive oil (VOO) in free and conjugated forms that may exert health benefits against atherosclerosis. The native form of HT is undetectable in plasma due to an extensive first pass phase II metabolism. Therefore, it is necessary to find strategies to obtain HT metabolites and to demonstrate their protective role against the endothelial dysfunction. METHODS AND RESULTS Biosynthesis of the main plasmatic HT metabolites was performed through Caco-2 cells. The bioactivity of HT and the mixture of metabolites was tested at physiological concentrations (1, 2, 5, and 10 μM) in human aortic endothelial cells (HAEC) co-incubated with TNF-α (10 ng/mL) for 18 and 24 h. After the incubations, cells and media were analyzed to test possible deconjugation of metabolites or conjugation of HT. Both HT and metabolites significantly reduced the secretion of E-selectin, P-selectin, ICAM-1, and VCAM-1, but only HT metabolites further reduced MCP-1 at 24 h. HT underwent a conjugation process after incubation leading to its main metabolites in a dose-dependent manner. CONCLUSION Physiological HT metabolites, synthetized for the first time by using an intestinal cell model, might be responsible in part for the protection against endothelial dysfunction.

Complementary phenol-enriched olive oil improves HDL characteristics in hypercholesterolemic subjects. A randomized, double-blind, crossover, controlled trial. The VOHF study.

SCOPE Consumption of olive oil (OO) phenolic compounds (PCs) has beneficial effects on lipid profile. HDL functionality is currently considered to be a more important issue than its circulating quantity. Our aim was to assess whether functional virgin olive oils (FVOOs), one enriched with its own PC (500 ppm; FVOO) and another with OOPC (250 ppm) plus additional complementary PCs from thyme (250 ppm) (total: 500 ppm; FVOOT (functional virgin olive oil with thyme)), could improve HDL functionality related properties versus a virgin OO control (80 ppm; VOO). METHODS AND RESULTS In a randomized, double-blind, crossover, controlled trial, 33 hypercholesterolemic volunteers received 25 mL/day of VOO, FVOO, and FVOOT during 3 wk. HDL cholesterol increased 5.74% (p < 0.05) versus its baseline after the FVOOT consumption in the participants without hypolipidemic medication. We detected, after FVOOT consumption, an increase in HDL2 -subclass (34.45, SD = 6.38) versus VOO intake (32.73, SD = 6.71). An increment in esterified cholesterol/free cholesterol and phospholipids/free cholesterol in HDL was observed after FVOOT consumption (1.73, SD = 0.56; 5.44, SD = 1.39) compared with VOO intervention (1.53, SD = 0.35; 4.97, SD = 0.81) and FVOO intervention (1.50, SD = 0.33; 4.97, SD = 0.81). Accordingly, lecithin-cholesterol acyltransferase mass increased after FVOOT consumption (1228 μg/mL, SD = 130), compared with VOO consumption (1160 μg/mL, SD = 144). An improvement in HDL oxidative-status was reflected after FVOOT consumption versus its baseline, given an increment in the paraoxonase activity (118 × 10(3) U/L, SD = 24). CONCLUSION FVOOT improves HDL-subclass distribution and composition, and metabolism/antioxidant enzyme activities. FVOOT could be a useful dietary tool in the management of high cardiovascular risk patients.

Polyphenol-rich foods exhibit DNA antioxidative properties and protect the glutathione system in healthy subjects.

SCOPE Polyphenols (ingested via food items) can decrease DNA, and oxidative damage of proteins and lipids. However, polyphenol effects in healthy populations have not been well defined. The aim of this study was to assess the relationship between urinary total polyphenol excretion (TPE), a biomarker of total polyphenol intake (TPI), polyphenol-rich foods, and oxidative stress biomarkers in healthy adults of different ages participating in the cross-sectional PAScual MEDicina study. METHODS AND RESULTS Urinary TPE was determined by Folin-Ciocalteau method in spot urine samples of 81 participants (46 women), classified into three age groups: 18 to 39, 40 to 54, and 55 to 72 years of age. TPI was quantified from 3-day dietary records using the Phenol-Explorer database. Urinary TPE increased with age (p < 0.001). Urinary TPE was inversely associated with urinary 8-hydroxydeoxyguanosine (8-OHdG; p<0.001) and erythrocyte-oxidized glutathione concentrations (p < 0.05). A negative association between urinary 8-OHdG and daily intake of polyphenols from vegetables and fermented beverages such as red wine was observed. CONCLUSION Urinary TPE increased with age and may reflect attenuation of oxidative damage. These results could explain the beneficial effects in healthy individuals of a diet rich in vegetables and moderate red wine; food items typical of the Mediterranean diet.

Alpha-Tocopherol and BAY 11-7082 Reduce Vascular Cell Adhesion Molecule in Human Aortic Endothelial Cells

Background: In endothelial dysfunction, vascular cell adhesion molecule-1 (VCAM-1), E-selectin and intercellular adhesion molecule-1 (ICAM-1) expression (collectively termed cell adhesion molecules; CAMs) increase at sites of atherosclerosis and are stimulated by proinflammatory cytokines such as tumor necrosis factor-α (TNF-α). Methods: We evaluated the effect of alpha-tocopherol (AT; 10–150 µM) and BAY 11-7082 (BAY; 0.1 or 1 µM) on CAMs mRNA expression as well as their protein in soluble release form (sCAMs) in human aortic endothelial cells (HAECs) activated by TNF-α (1 or 10 ng/ml). Also, we determined the extent of lymphocyte adhesion to activated HAECs. Results: BAY reduced VCAM-1, E-selectin and ICAM-1 mRNA expression by 30, 30 and 10%, respectively. Furthermore, protein reduction of sVCAM-1 by 70%, sE-selectin by 51% and sICAM-1 by 25% compared to HAECs stimulated by TNF-α was observed (p < 0.05). AT (50, 75 and 150 µM) decreased VCAM-1 mRNA expression by 30% and sVCAM-1 protein by 33% compared to HAECs stimulated by TNF-α (p < 0.05). TNF-α-activated HAEC adhesion to human Jurkat T lymphocytes was higher compared to nonactivated HAECs (p < 0.05). BAY (2 and 5 µM) reduced this lymphocyte adhesion (p < 0.05). Conclusion: BAY reduces all the CAMs studied as well as cell adhesion, while AT selectively inhibits VCAM-1; both induce endothelial dysfunction improvement.

Impact of Virgin Olive Oil and Phenol-Enriched Virgin Olive Oils on the HDL Proteome in Hypercholesterolemic Subjects: A Double Blind, Randomized, Controlled, Cross-Over Clinical Trial (VOHF Study).

The effects of olive oil phenolic compounds (PCs) on HDL proteome, with respect to new aspects of cardioprotective properties, are still unknown. The aim of this study was to assess the impact on the HDL protein cargo of the intake of virgin olive oil (VOO) and two functional VOOs, enriched with their own PCs (FVOO) or complemented with thyme PCs (FVOOT), in hypercholesterolemic subjects. Eligible volunteers were recruited from the IMIM-Hospital del Mar Medical Research Institute (Spain) from April 2012 to September 2012. Thirty-three hypercholesterolemic participants (total cholesterol >200mg/dL; 19 men and 14 women; aged 35 to 80 years) were randomized in the double-blind, controlled, cross-over VOHF clinical trial. The subjects received for 3 weeks 25 mL/day of: VOO, FVOO, or FVOOT. Using a quantitative proteomics approach, 127 HDL-associated proteins were identified. Among these, 15 were commonly differently expressed after the three VOO interventions compared to baseline, with specific changes observed for each intervention. The 15 common proteins were mainly involved in the following pathways: LXR/RXR activation, acute phase response, and atherosclerosis. The three VOOs were well tolerated by all participants. Consumption of VOO, or phenol-enriched VOOs, has an impact on the HDL proteome in a cardioprotective mode by up-regulating proteins related to cholesterol homeostasis, protection against oxidation and blood coagulation while down-regulating proteins implicated in acute-phase response, lipid transport, and immune response. The common observed protein expression modifications after the three VOOs indicate a major matrix effect. Trial Registration International Standard Randomized Controlled Trials ISRCTN77500181.