Triacylglycerol-rich lipoproteins derived from healthy donors fed different olive oils modulate cytokine secretion and cyclooxygenase-2 expression in macrophages: the potential role of oleanolic acid.

PURPOSE: Current evidence suggests that consumption of virgin olive oil (VOO) helps to protect against the development of atherosclerosis and that minor components such as oleanolic acid contribute to this effect. In this study, the effects of triacylglycerol-rich lipoproteins (TRLs) derived from olive oil on inflammatory processes in macrophages and how they are modulated by oleanolic acid was investigated. METHODS: TRLs isolated from healthy volunteers 2 and 4 h after a test meal containing VOO, pomace olive oil (POO) (the second pressing of olive oil, enriched in minor components) or POO enriched with oleanolic acid (OPOO) were incubated with macrophages derived from the human monocyte cell line, THP-1. RESULTS: All types of TRLs caused a decrease of about 50% in the secretion of monocyte chemoattractant protein-1 (MCP-1) by the cells. Interleukin (IL)-6 secretion was also significantly decreased by 2 and 4 h VOO TRLs and by 4 h OPOO TRLs. In contrast, increased IL-1ß secretion was observed with all 2 h TRL types, and increased tumour necrosis factor-α (TNF-α) production with 2 h VOO and POO, but not OPOO, TRLs. TRLs isolated after 4 h, however, had no significant effects on TNF-α secretion and increased IL-1ß secretion only when they were derived from VOO. Cyclooxygenase-2 (COX-2) mRNA expression was strongly down-regulated by all types of TRLs, but protein expression was significantly depressed only by 4 h OPOO TRLs. CONCLUSION: These findings demonstrate that TRLs derived from olive oil influence inflammatory processes in macrophages and suggest that oleanolic acid may have beneficial effects.

Components of the Mediterranean-type food pattern and serum inflammatory markers among patients at high risk for cardiovascular disease.

OBJECTIVE: To evaluate associations between components of the Mediterranean diet and circulating markers of inflammation in a large cohort of asymptomatic subjects at high risk for cardiovascular disease. SUBJECTS/METHODS: A total of 339 men and 433 women aged between 55 and 80 years at high cardiovascular risk because of presence of diabetes or at least three classical cardiovascular risk factors, food consumption was determined by a semi-quantitative food frequency questionnaire. Serum concentrations of high-sensitivity C-reactive protein (CRP) were measured by immunonephelometry and those of interleukin-6 (IL-6), intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by enzyme-linked immunosorbent assay. RESULTS: After adjusting for age, gender, body mass index, diabetes, smoking, use of statins, non-steroidal antiinflammatory drugs and aspirin, a higher consumption of fruits and cereals was associated with lower concentrations of IL-6 (P for trend 0.005;both). Subjects with the highest consumption of nuts and virgin olive oil showed the lowest concentrations of VCAM-1, ICAM-1, IL-6 and CRP; albeit only for ICAM-1 was this difference statistically significant in the case of nuts (for trend 0.003) and for VCAM-1 in the case of virgin olive oil (P for trend 0.02). Participants with higher adherence to the Mediterranean-type diet did not show significantly lower concentrations of inflammatory markers (P<0.1 for VCAM-1 and ICAM-1). CONCLUSIONS: The consumption of some typical Mediterranean foods (fruits, cereals, virgin olive oil and nuts) was associated with lower serum concentrations of inflammatory markers especially those related to endothelial function, in subjects with high cardiovascular risk living in a Mediterranean country.

Effect of two high-oleic oils on the liver lipid composition of spontaneously hypertensive rats.

Despite having similar fatty acid composition and plasma lipid composition after ingestion, olive oil, but not high-oleic sunflower oil (HOSO), is capable of reducing blood pressure. HOSO contains mainly triolein, whereas olive oil contains important amounts of dioleoyl-palmitoyl-glycerol. In order to see if its different triacylglycerol (TAG) composition could be related to the hypotensive effect of olive oil, Spontaneously Hypertensive Rats (SHR) were fed with HOSO and olive oil-rich diets. Liver lipid composition was determined. Total lipid, fatty acid and TAG composition was analyzed. Rats fed olive oil (67.24 +/- 4.23) were observed to retain more dioleoyl-acyl-glycerol species in their liver than those fed HOSO (56.6 +/- 3.95), specially triolein (20.69 +/- 1.77 olive oil, vs. 12.54 +/- 1.97 HOSO), in spite of its lower content of this TAG. On the contrary, rats consuming HOSO had higher amounts of dilinoleoyl-acyl-glycerol species (9.26 +/- 1.57 HOSO, vs.4.02 +/- 0.90 olive oil). In conclusion, olive oil provided a more beneficial TAG profile in the liver of SHR rats than HOSO, probably due to the differences in the TAG composition of both oils.

Incorporation of dietary triacylglycerols from olive oil and high-oleic sunflower oil into VLDL triacylglycerols of hypertensive patients.

OBJECTIVES: To establish whether the ingestion of diets enriched with olive oil or high-oleic sunflower oil may produce changes in the composition of VLDL triacylglycerols from hypertensive patients. It could be relevant for the uptake and metabolism of triacylglycerol-derived metabolites by extrahepatic tissues. DESIGN: Patients were assigned to the diets in a random-order sequence. SUBJECTS: The participants were 24 hypertensive patients recruited from a religious community. INTERVENTIONS: The study was conducted over two four week periods with a four week washout period between both MUFA diets. RESULTS: Dietary olive oil kept in balance the content of saturated fatty acids and decreased the content of arachidonic acid in VLDL triacylglycerols. HOSO diet reduced the content of palmitic acid and increased the content of linoleic acid. There was also a decrease in trioleate-glycerol and an increase in tripalmitate-glycerol of VLDL after the MUFA diets, but these effects were more pronounced in the HOSO group. Intake of olive oil decreased the content of disaturated triacylglycerols and increased the content of dioleate-containing triacylglycerols. A decrease in palmitate-dioleate-glycerol after dietary HOSO was observed. Olive oil (but not HOSO) promoted the presence of long-chain PUFA of n-3 family at the sn-2 position of VLDL triacylglycerols. CONCLUSIONS: Our data indicate that olive oil and HOSO, providing a similar concentration of MUFA (oleic acid), differ in the formation of VLDL triacylglycerols in hypertensive patients.

Dietary virgin olive oil triacylglycerols as an independent determinant of very low-density lipoprotein composition.

OBJECTIVE: We examined the effects of virgin olive oil (VOO) triacylglycerols (TGs) on the lipid composition of human very low-density lipoprotein (VLDL). METHODS: Twenty-one normocholesterolemic, normotensive, non-diabetic elderly subjects were recruited for the study. Two VOOs (VOO1 and VOO2) of the same variety, with an equivalent composition in minor components and differing only in the oleic and linoleic acid concentrations, were administered for 4 wk each to assess the effect of their TG molecular species compositions. Blood was collected after an overnight fast, VLDLs were isolated by ultracentrifugation, and lipid classes, TG molecular species, and TG fatty acid composition were determined. RESULTS: Dietary VOOs significantly differed in TG molecular species composition. VOO1 represented larger amounts of triolein (P < 0.01), whereas VOO2 was significantly enriched with dilinoleoyl-oleoyl-glycerol, linoleoyl-dioleoyl-glycerol, and linoleoyl-oleoyl-palmitoyl-glycerol (P < 0.01). For VLDL, intake of VOO1 caused an increase of total TG (P < 0.01) due mainly to increases in triolein and linoleoyl-dioleoyl-glycerol. Conversely, VOO2 increased VLDL cholesteryl esters (P < 0.01) and TG rich in arachidonic acid (P < 0.01). CONCLUSIONS: The different TG molecular species compositions of dietary oils may be an independent determinant of the lipid composition of VLDL in elderly people and therefore may play a role in regulating lipoprotein metabolism in these subjects.

Triacylglycerol-rich lipoproteins interact with human vascular cells in a lipid-dependent fashion.

Plasma triacylglycerol-rich lipoproteins (TRL) are being considered as a key lipid fraction in the pathogenesis of atherosclerotic cardiovascular disease. Here we compared the influence of two monounsaturated oils [virgin olive oil (VOO) and high-oleic sunflower oil (HOSO)] on the capability of postprandial TRL to interact with two human vascular cell lines [umbilical vein endothelial (HUVEC) and aorta smooth muscle (HASMC) cells]. A fluorescent probe was used for labeling TRL and to determine receptor activity of HUVEC and HASMC. The values for total cell-associated, bound, and internalized TRL were higher in HUVEC, and TRL from VOO was the better ligand recognized but at lower affinity than TRL from HOSO. There was a competitive effect of very low density lipoproteins (VLDL) for the uptake of TRL by cells, which was found to be dependent on the origin/lipid composition of the ligands and cell-type specific. We also conclude that the VLDL receptor (VLDLr) may contribute significantly to the HASMC binding capacity for postprandial TRL mediated by lipoprotein lipase (LPL) or LPL-binding molecules. Our findings are compatible with a selective role of the clustered O-linked sugar domain of the VLDLr in the catabolism of TRL by human vascular cells.

[Influence of a program of physical activity in children and obese adolescents; evaluation of physiological stress by compounds in saliva; study protocol]. / Influencia de un programa de actividad física en niños y adolescentes obesos; evaluación del estrés fisiológico mediante compuestos en la saliva; protocolo de estudio.

Different studies4, 5 relate that stress increases in children and adolescents with overweight and obesity, and consequently their salivary physiological responses (AEA salivary alpha-amylase, cortisol, cytokines, leptin), so in this study we relate these two parameters to see their progress through a program of physical activity. If we manage to reduce overweight or obesity, these physiological responses and stress should also be reduced, thus improving the overall health status of these children and adolescents. The overall objective of the study was to determine the influence of physical activity in obese children and adolescents in perceived stress. An observational, descriptive, prospective and longitudinal study will be carried out. The universe is made up of 60 overweight / obese children and adolescents aged between 10 and 18 years. The assessment will take place from September 2012 to September 2013. To collect saliva samples, the ELISA8 method will be used. Variables such as BMI, lifestyle and diet will also be collected Among the expected results are to lower overweight and obesity in children through physical activity program. To reduce stress and to normalize physiological salivary parameters.

Diferentes estudios1,2 relacionan que el estrés aumenta en los niños y adolescentes con sobrepeso y obesidad, y en consecuencia sus respuestas fisiológicas salivales (Alfaamilasa salivar AEA, Cortisol, Citoquinas, Leptina), por eso en este estudio queremos relacionar estos dos parámetros para ver su evolución a través de un programa de Actividad Física. Si logramos reducir el sobrepeso u obesidad se debería reducir también estas respuestas fisiológicas y el estrés, por lo que mejoraría el estado de salud general de estos niños y adolescentes. El objetivo general del estudio es conocer la influencia de la actividad física, en niños y adolescentes obesos, en el estrés percibido. Se realizará un estudio observacional, descriptivo, prospectivo y longitudinal. El universo estará constituido por 60 niños y adolescentes con edades comprendidas entre 10 y 18 con sobrepeso/obesidad. La valoración tendrá lugar desde septiembre de 2012 hasta septiembre de 2013. Para la recogida de las muestras de saliva se utilizará el método ELISA3. También se recogerán variables como el IMC, hábitos de vida y alimentación. De entre los resultados esperados están el bajar el sobrepeso y obesidad en los niños mediante el programa de actividad física. Disminuir el estrés fisiológico y normalizar los parámetros salivares.

[Study of the serum levels of leptin, ceruloplasmin and lipoprotein (a) as indicators of cardiovascular risk in a population of adolescents in Granada (Spain)]. / Estudio de los niveles séricos de leptina, ceruloplasmina y lipoproteína (a) como indicadores del riesgo cardiovascular en una población de adolescentes de Granada (España).

Numerous studies have focused on establishing a relation between the serum values of biomolecules such as leptin, ceruloplasmin, and lipoprotein (a), and the nutritional state and levels of diastolic and systolic blood pressure in subjects with problems of overweight or obesity. However, in many cases, the results obtained have not been conclusive. The results of our study confirm the existence of a statistically significant association between the serum levels of these biomolecules, the nutritional state of the subjects, and levels of diastolic and systolic blood pressure. For the population of overweight and obese adolescents studied, the evaluation of the serum concentrations of these biomolecules was found to be an important instrument that could be used to identify those subjects with an elevated risk of suffering cardiovascular disorders basically derived from a hypertensive status.

[Ceruloplasmin and its clinical relevance as an indactor of cardiovascular risk factor in a school population of Granada]. / Ceruloplasmina y su importancia clínica como factor indicador del riesgo cardiovascular en una población de escolares de Granada.

Also known as ferroxidase ceruloplasmin, belongs to the family of inflammation-sensitive proteins, and its main function to transport copper in the blood. Although, in addition to this transport function, at present, there are numerous studies that have attempted to use the determination of serum concentrations as a predictive indicator of cardiovascular risk in patients who are overweight or obese. The results of this study confirm the existence of a significant correlation between serum ceruloplasmin and nutritional status of the subjects, which means that for the population of students assessed, serum levels of this protein are an important predictor the risk of cardiovascular disease.

Modulation of the effects of chylomicron remnants on endothelial function by minor dietary lipid components.

There is emerging evidence that minor components from dietary oils can modulate or even improve events occurring in the development of atherosclerosis. One of the earliest events of the atherosclerotic process is endothelial dysfunction, which is an activation of the endothelium manifested by an increase in pro-inflammatory molecules, such as cytokines and adhesion molecules. Chylomicron remnants, such as LDL (low-density lipoprotein), are considered to be pro-atherogenic lipoproteins because they interact with endothelial cells and macrophages, increasing endothelial dysfunction mainly by the disturbance of the redox state in the cell. However, chylomicrons are, at the same time, the natural carriers of dietary lipids in plasma, which gives minor lipid components the opportunity to interact with the cells implicated in endothelial dysfunction and atherogenesis. Some of these components are known to exhibit antioxidant, anti-inflammatory and anti-atherogenic effects in vitro, even forming part of triacylglycerol-rich lipoproteins, such as chylomicrons.

Influence of minor components of olive oils on the composition and size of TRLs and on macrophage receptors involved in foam cell formation.

Metabolic and epidemiologic studies support the idea that the type of dietary fat is more important than the total amount of fat with respect to the development of atherosclerosis and the risk of cardiovascular heart disease. Dietary fat is carried in CMs (chylomicrons), which can be taken up by macrophages without need of further oxidation, leading to the formation of foam cells and initiating or aggravating the atherogenic process. Evidence from different studies has shown that dietary fat can influence the composition and size of TRLs (triacylglycerol-rich lipoproteins), which might modulate their atherogenicity to a certain extent. In particular, experiments in vitro have shown the anti-atherogenic effects of minor components from olive oil when forming part of TRL, as these particles give minor lipid components the opportunity to interact with the cells implicated in endothelial dysfunction and atherogenesis. However, the exact mechanisms mediating CM uptake by macrophages still remain unclear. Thus further studies are needed to understand how the modifications of TRL composition caused by dietary fats could modulate the expression of macrophage receptors and foam cell formation, or even improve the atherogenic risk of these particles.

Determination of rat liver triglycerides by gas-liquid chromatography and reversed-phase high-performance liquid chromatography.

Rats fed with a fat-free or an olive oil-rich diet were employed to compare the response of two chromatographic techniques in the determination of rat liver triglyceride (TG) molecular species composition. Gas-liquid chromatography (GLC) on polarizable liquid phase and reversed-phase high-performance liquid chromatography (RP-HPLC) have been commonly employed for TG analysis, obtaining a similar number of chromatographic peaks when used for animal tissue TG determination. In the present study similar results were achieved with regard to most relevant chromatographic peaks, however, important differences were found in the content of minor TGs. Indeed, RP-HPLC permitted separation of long chain polyunsaturated fatty acids, which were not detected by GLC, while the latter technique reported a higher number of myristoyl-containing TG species. RP-HPLC analysis reported a greater number of TGs, with more similarity to a random composition, made up from the liver fatty acid composition. Therefore, it was concluded that utilization of both techniques would be helpful for liver TG analysis as the use of only one of them does not provide a complete profile of liver TGs. Nevertheless RP-HPLC seems to be more useful for this purpose since revealed a more extensive profile.

The metabolic availability of dietary triacylglycerols from two high oleic oils during the postprandial period does not depend on the amount of oleic acid ingested by healthy men.

Monounsaturated oils, virgin olive oil (VOO) and high oleic sunflower oil (HOSO) are suggested to have selective physiologic effects on humans in the fasting state. The aim of the study was to evaluate whether two oils with equal amounts of oleic acid but with different compositions of minor fatty acids and triacylglycerol molecular species (TAG) could produce different triacylglycerol-rich lipoprotein (TRL)-TAG responses in the postprandial state. Eight normolipidemic men consumed the following three meals in random order on separate occasions with 2 wk between meals: control meal, control meal plus VOO and control meal plus HOSO. Plasma total TAG and TRL-TAG were measured hourly for 7 h after ingestion. TAG and sn-2 positional fatty acids within TAG were analyzed in the TRL fraction. Plasma total TAG concentrations in response to the dietary oils did not differ. However, TRL triglyceridemia was significantly lower after VOO intake (P < 0.05). The molecular species in the TRL fraction returned toward basal levels more quickly (P < 0.05) after VOO than HOSO intake. 2-Positional fatty acid analysis demonstrated higher proportions of stearic and palmitic acids and a lower proportion of oleic acid (P < 0.05) in TRL-TAG derived from HOSO. This study shows that VOO intake results in attenuated postprandial TAG concentration and faster TRL-TAG disappearance from blood compared with HOSO, suggesting that the oleic acid content may not be the main factor affecting TAG metabolism. Minor fatty acids such as linoleic acid and the 2-positional distribution of saturated stearic and palmitic acids into the TAG molecule may be important determinants of postprandial lipemia in normolipidemic men.

Influence of different dietary fats on triacylglycerol deposition in rat adipose tissue.

It has been demonstrated that triacylglycerol (TAG) mobilization from adipose tissue is selective and depends on fatty acid (FA) chain length, unsaturation and positional isomerism. The present study was performed to determine the influence of dietary fat on the composition of TAG stored in rat perirenal and subcutaneous adipose tissues. These results may provide information on the susceptibility of stored TAG to hydrolysis and further mobilization, and may help to establish an interrelationship between dietary composition and the FA efflux from adipose tissue. TAG molecular species and FA composition were determined by HPLC and GLC respectively. No significant differences were found in either FA or TAG composition between perirenal and subcutaneous adipose depots. The major FA in the dietary fats were present in the adipose tissues of the animals; in most cases, in similar proportions. However, differences were found between dietary and adipose tissue content of minor FA, which suggests that dietary FA composition is altered between ingestion and deposition in adipose tissue. The TAG molecular species of rat adipose tissue were enriched with the FA characteristic of each dietary fat. Dietary sunflower oil was responsible for enrichment with the most polar TAG. This finding may suggest easier mobilization of stored TAG. In conclusion, the process of fatty acid and TAG deposition in rat adipose tissue is selective, and depends on the composition of the diet.

Postprandial triacylglycerols from dietary virgin olive oil are selectively cleared in humans.

The aims of the present study were to evaluate the effect of a meal rich in virgin olive oil on triacylglycerol composition of human postprandial triacylglycerol-rich lipoproteins (fraction Sf > 400), and to assess the role of the triacylglycerol molecular species concentration and polarity on lipoprotein clearance. Fasting (0 h) and postprandial blood samples were collected hourly for 7 h from eight healthy normolipidemic subjects after the ingestion of the meal. Plasma and lipoprotein triacylglycerol concentrations increased quickly over fasting values and peaked twice at 2 and 6 h during the 7-h postprandial period. The triacylglycerols in the lipoprotein fraction at 2 h generally reflected the composition of the olive oil, however, the proportions of the individualmolecular species were altered by the processes leading to their formation. Among the major triacylglycerols, the proportion of triolein (OOO; 43.6%) decreased (P < 0.05), palmitoyl-dioleoyl-glycerol (POO; 31. 1%) and stearoyl-dioleoyl-glycerol (SOO; 2.1%) were maintained and linoleoyl-dioleoyl-glycerol (LOO; 11.4%) and palmitoyl-oleoyl-linoleoyl-glycerol (POL; 4.6%) significantly increased (P < 0.05) compared with the composition of the triacylglycerols in the olive oil. Smaller amounts of endogenous triacylglycerol (0.8%), mainly constituted of the saturated myristic (14:0)and palmitic (16:0) fatty acids, were also identified. Analysis of total fatty acids suggested the presence of molecular species composed of long-chain polyunsaturated fatty acids of the (n-3) family, docosapentaenoic acid, [22:5(n-3)] and docosahexaenoic acid (DHA), [22:6(n-3)] and of the (n-6) family [arachidonic acid, [20:4(n-6)]. The fastest conversion of lipoproteins to remnants occurred from 2 to 4 h and was directly related to the concentration of the triacylglycerols in the lipoprotein particle (r = 0.9969, P < 0.05) and not with its polarity (r = 0.1769, P > 0.05). The rates of clearance were significantly different among the major triacylglycerols (OOO, POO, OOL and POL) (P < 0.05) and among the latter ones and PLL (palmitoyl-dilinoleoyl-glycerol, POS (palmitoyl-oleoyl-stearoyl-glycerol) and OLL (oleoyl-dilinoleoyl-glycerol) (P < 0.01). OOO was removed faster and was followed by POO, OOL, POL, PPO (dipalmitoyl-oleoyl-glycerol), SOO, PLL, POS and OLL.

Modifications induced by dietary lipid source in adipose tissue phospholipid fatty acids and their consequences in lipid mobilization.

The aim of the present work was to assess the influence of dietary lipid source on fatty acid phospholipid profiles and on lipid mobilization. Forty male Wistar rats were divided into four groups and fed on high-fat diets which provided olive oil, sunflower oil, palm oil or beef tallow. All rats received the same amount of energy to avoid hyperphagia and differences in energy intake among groups. Phospholipid fatty acids were determined by GC. Lipolysis was stimulated in subcutaneous and perirenal isolated adipocytes by several lipolytic agents, and assessed by the determination of released glycerol. After 4 weeks of feeding, differences in body and adipose tissue weights were not observed. Dietary regimens caused great changes in adipose tissue phospholipid composition: rats fed on palm oil and beef tallow had higher concentrations of saturated fatty acids and animals fed on olive oil or sunflower oil had greater amounts of oleic and linoleic acids, respectively. These modifications did not lead to important changes in adipocyte lipolysis. Significant differences were only observed between palm-oil- and beef-tallow-fed groups when lipolysis was stimulated by isoproterenol in subcutaneous adipocytes. The fact that our feeding protocol did not induce differences in fat accumulation among groups avoids misinterpretations due to adiposity changes. The differences observed between both saturated-fat-fed groups, therefore, should only be attributable to dietary lipids. Despite this effect, the data from this work indicate that some diet-induced changes in adipose tissue fatty acid composition may have little effect on overall function.