Biomedical subjects

J L Quiles

Publications and source records attributed to J L Quiles.

At least 19 recordsLinked to original sources

PubMed2003

Virgin olive and fish oils enhance the hepatic antioxidant defence system in atherosclerotic rabbits.

BACKGROUND & AIMS: In this study we report the effects of sunflower, virgin olive and fish oils on the lipid profile and antioxidant defence system in liver mitochondria from rabbits with experimental atherosclerosis. METHOD: An atherogenic control group were fed for 50 days on a diet containing 3% lard and 1.3% cholesterol. Four groups were fed for an additional period of 30 days with a diet enriched in different oils: sunflower oil, virgin olive oil, refined olive oil and fish oil. A control group was fed with a standard chow. RESULTS: The atherogenic diet caused important changes in the hepatic mitochondria lipid profile and in the enzymatic and non-enzymatic antioxidant defence system accompanied with an increase in the content of hydroperoxides in liver mitochondria. The administration of virgin olive and fish oils showed a better profile in the antioxidant system as well as decrease in the content of hydroperoxides. CONCLUSIONS: The intake of cholesterol- and lard-enriched diet leads to a high impairment in the hepatic antioxidant defence system. However, the replacement of that diet by other unsaturated fat-enriched diets using virgin olive, sunflower and fish oil enhances hepatic antioxidant defence system, virgin olive and fish oil diet provide the best results.

Animals↗

PubMed2001

Dietary fat type and regular exercise affect mitochondrial composition and function depending on specific tissue in the rat.

Physical exercise and fatty acids have been studied in relation to mitochondrial composition and function in rat liver, heart, and skeletal muscle. Male rats were divided into two groups according to dietary fat type (virgin olive and sunflower oils). One-half of the animals from each group were subjected to a submaximal exercise for 8 weeks; the other half acted as sedentary controls. Coenzyme Q, cytochromes b, c + c1, a + a3 concentrations, and the activity of cytochrome c oxidase were determined. Regular exercise increased (P < 0.05) the concentration of the above-mentioned elements and the activity of the cytochrome c oxidase by roughly 50% in liver and skeletal muscle. In contrast, physical exercise decreased (P < 0.05) cytochrome c oxidase activity in the heart (in micromol/min/g, from 8.4+/-0.1 to 4.9+/-0.1 in virgin olive oil group and from 9.7+/-0.1 to 6.7+/-0.2 in sunflower oil animals). Dietary fat type raised the levels of coenzyme Q, cytochromes, and cytochrome c oxidase activity in skeletal muscle (P < 0.05) among the rats fed sunflower oil. In conclusion, dietary fat type, regular exercise, and the specific tissue modulate composition and function of rat mitochondria.

Animals↗

PubMed2000

Cerebral cortex synaptic heavy mitochondria may represent the oldest synaptic mitochondrial population: biochemical heterogeneity and effects of L-acetylcarnitine.

The microheterogeneous nature of intrasynaptic mitochondria has been demonstrated and is widely accepted. However, evidence is still lacking about the role played by the different intrasynaptic mitochondrial subpopulations. The data obtained support the hypothesis that "heavy" mitochondria could represent old mitochondrial populations: in fact, in addition to the well known impairment of typical mitochondrial functions, they possess the highest levels of hydroperoxides and their fatty acids pattern is completely modified. The qualitative and quantitative fatty acid modifications suffered by these organelles deeply altered their protein/lipid ratio, thus modifying their mode of action. The present work also collects a large body of evidence that a subchronic L-acetylcarnitine treatment in 28 days does not structurally affect both nonsynaptic and intrasynaptic mitochondria of normal rat in a "steady-state" metabolic condition.

Acetylcarnitine↗

PubMed1999

Olive oil supplemented with vitamin E affects mitochondrial coenzyme Q levels in liver of rats after an oxidative stress induced by adriamycin.

In this study we have evaluated the supplementation of olive oil with vitamin E on coenzyme Q concentration and lipid peroxidation in rat liver mitochondrial membranes. Four groups of rats were fed on virgin olive, olive plus 200 mg/kg of vitamin E or sunflower oils as lipid dietary source. To provoke an oxidative stress rats were administered intraperitoneally 10 mg/kg/day of adriamycin the last two days of the experiment. Animals fed on olive oil plus vitamin E had significantly higher coenzyme Q and vitamin E levels but a lower mitochondrial hydroperoxide concentration than rats fed on olive oil. Retinol levels were not affected, by either different diets or adriamycin treatment. In conclusion, an increase in coenzyme Q and alpha-tocopherol in these membranes can be a basis for protection against oxidation and improvement in antioxidant capacity.

Animals↗

PubMed1999

Oral administration of a turmeric extract inhibits LDL oxidation and has hypocholesterolemic effects in rabbits with experimental atherosclerosis.

The oxidation of low-density lipoproteins (LDL) plays an important role in the development of atherosclerosis. Curcumin is a yellow pigment obtained from rhizomes of Curcuma longa and is commonly used as a spice and food colouring. Curcumin and turmeric extracts have several pharmacological effects including antitumour, anti-inflammatory, antioxidant and antiinfectious activities although the precise mechanisms involved remain to be elicited. We evaluated the effect of an ethanol-aqueous extract obtained from rhizomes of C. longa on LDL oxidation susceptibility and plasma lipids in atherosclerotic rabbits. A total of 18 rabbits were fed for 7 weeks on a diet containing 95.7% standard chow, 3% lard and 1. 3% cholesterol, to induce atherosclerosis. The rabbits were divided into groups, two of which were also orally treated with turmeric extract at doses of 1.66 (group A) and 3.2 (group B) mg/kg body weight, respectively. A third group (group C) acted as a control. Plasma and LDL lipid composition, plasma alpha-tocopherol, plasma retinol, LDL TBARS, LDL lipid hydroperoxides and analysis of aortic atherosclerotic lesions were assayed. The low but not the high dosage decreased the susceptibility of LDL to lipid peroxidation. Both doses had lower levels of total plasma cholesterol than the control group. Moreover, the lower dosage had lower levels of cholesterol, phospholipids and triglycerides in LDL than the 3.2-mg dosage. In conclusion, the use of this extract could be useful in the management of cardiovascular disease in which atherosclerosis is important.

Administration, Oral↗

PubMed1999

Oxidative stress induced by exercise and dietary fat modulates the coenzyme Q and vitamin A balance between plasma and mitochondria.

Physical exercise induces oxidative stress. Dietary fat modulates lipid composition of plasma and fatty acid profile of mitochondrial membranes. Over 8 wk, two groups of rats were fed virgin olive oil or sunflower oil as the only fat sources. Both groups were divided into 4 subgroups according to exercise: one of sedentary rats and the other three of rats subjected to different exercises on a treadmill. There was a lower concentration of vitamin A and coenzyme Q in the plasma of animals subjected to exercise compared to the sedentary animals. The concentrations of these molecules in liver and skeletal muscle mitochondria of animals exercised until exhaustion were higher than in sedentary animals. This can suggest the existence of a balance between plasma and mitochondrial membrane for these antioxidants as a response to an oxidative attack.

Animals↗

PubMed1999

Vitamin E supplementation increases the stability and the in vivo antioxidant capacity of refined olive oil.

Two experiments were carried out to investigate if the supplementation with vitamin E affects refined olive oil response to oxidation regarding the stability of the oil and the protection in vivo against lipid peroxidation in rats after its intake in comparison with other edible oils. In experiment 1, samples of virgin olive oil, refined olive oil, refined olive oil supplemented by us with 200 mg/kg vitamin E, and sunflower oil were collected before and after a 60 min frying process. After frying, refined olive oil supplemented with vitamin E compared with the non-supplemented refined olive oil had a higher concentration of alpha-tocopherol (240.34+/-6.07 mg/kg vs. 131.94+/-8.14 mg/kg), more resistance against oxidation (19.01+/-1.88% vs. 10.6+/-2.08%) and less polar components (4.2+/-0.06% vs. 5.45+/-0.22%). In experiment 2, 24 male Wistar rats, divided into 4 groups, were fed on diets based on the same unfried oils (8% w/w) as in experiment 1, for 4 weeks. Two days prior to the end of the experiment, the rats were intraperitoneally administered with adriamycin (10 mg/kg/ day) to provoke an oxidative stress. The rats fed on refined olive oil plus vitamin E compared to the rats fed on non-supplemented refined olive oil had lower hydroperoxides concentrations (26.8+/-2.6 nmol/mg vs. 35.6+/-2.49 nmol/mg) higher coenzyme Q levels (128.1+/-11.97 pmol/mg vs. 81.25+/-9.25 pmol/mg) and higher alpha-tocopherol values (1.23+/-0.04 mmol/mg vs. 0.93+/-0.06 mmol/mg) in microsomes of liver. In conclusion, the supplementation of refined olive oil with 200 mg/kg of vitamin E increases the stability of this oil under pro-oxidant conditions, and its intake decreases the oxidative damage generated by adriamycin in rats.

Animals↗

PubMed1999

Physical exercise affects the lipid profile of mitochondrial membranes in rats fed with virgin olive oil or sunflower oil.

The effects of physical exercise on the lipid profile in mitochondrial membranes of liver and skeletal muscle were examined in rats fed with virgin olive oil or sunflower oil. Thirty male Wistar rats, 21 d old, were randomly assigned to four groups according to fat ingestion and physical activity over an 8-week period. For each type of oil, one group acted as a control group while rats from the other were trained to run for 40 min daily on a horizontal treadmill, at a speed of 35 m/min. The results show that diet affected the fatty acid profile of the mitochondrial membranes from skeletal muscle and liver. Physical exercise also modified the fatty acid profile of the mitochondrial membranes. Total monounsaturated fatty acids decreased (P < 0.001) in liver mitochondria of exercised animals. Total polyunsaturated fatty acids in mitochondrial membranes of liver increased (P < 0.005) after exercise but those in mitochondrial membranes of skeletal muscle decreased (P < 0.05). These changes due to the exercise may arise via several mechanisms, e.g. fluidity regulation; changes in the eicosanoid metabolism; differences in the availability or oxidation rate of the different fatty acids.

Analysis of Variance↗

PubMed1999

Relative importance of the saponified and unsaponified fractions of dietary olive oil on mitochondrial lipid peroxidation in rabbit heart.

The effects of four edible oils on lipid peroxidation have been investigated in rabbit heart mitochondrial membranes. The experimental oils (olive oil from the variety "picual", washed olive oil from the variety "picual", olive oil from the variety "arbequina" and high-oleic sunflower oil) had a similar fatty-acid composition, but differed in their unsaponified fraction (polyphenols, tocopherols, and others). The lowest hydroperoxide levels were found with picual and washed picual. No differences in mitochondrial membrane thiobarbituric acid reactive substance (TBARS), alpha-tocopherol concentrations and cytosolic antioxidant enzymes (superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase) were found, whereas the CoQ10 content correlated inversely with hydroperoxide levels in all groups. These results suggest that mitochondrial membranes with high levels of monounsaturated fatty acids generate low levels of lipid peroxidation. Moreover, the saponified fraction of the experimental diets proved more important in preventing lipid peroxidation than the unsaponified fraction. Lastly, coenzyme Q may help to prevent peroxidative stress damage in rabbit heart mitochondria.

Analysis of Variance↗

PubMed1998

Tissue specific interactions of exercise, dietary fatty acids, and vitamin E in lipid peroxidation.

Both physical exercise and ingestion of polyunsaturated fatty acids that play an essential role in free radical-mediated damages cause lipid peroxidation. The intake of specific fatty acids can modulate the membrane susceptibility to lipid peroxidation. Data confirmed that liver, skeletal muscle, and heart have different capabilities to adapt their membrane composition to dietary fatty acids, the heart being the most resistant to changes. Such specificity affects membrane hydroperoxide levels that depend on the type of dietary fats and the rate of fatty acid incorporation into the membrane. Sedentary rats fed a monounsaturated fatty acid-rich diet (virgin olive oil) showed a higher protection of their mitochondrial membranes against peroxidation than sedentary rats fed a polyunsaturated fatty acid-rich diet (sunflower oil). Rats subjected to training showed higher hydroperoxide contents than sedentary animals, and exhaustive effort enhanced the aforementioned results as well as in vitro peroxidation with a free radical inducer. This study suggests that peroxide levels first depend on tissue, then on diet and lastly on exercise, both in liver and muscle but not in heart. Finally, it appears that alpha-tocopherol is a less relevant protective agent against lipid peroxidation than monounsaturated fatty acids.

Adaptation, Physiological↗

PubMed1998

An ethanolic-aqueous extract of Curcuma longa decreases the susceptibility of liver microsomes and mitochondria to lipid peroxidation in atherosclerotic rabbits.

Atherosclerosis is characterized by oxidative damage which affects lipoproteins, the walls of blood vessels and subcellular membranes. This study evaluates the antioxidant capacity of a Curcuma longa extract on the lipid peroxidation of liver mitochondria and microsome membranes in atherosclerotic rabbits. Male rabbits fed a 3% (w/w) lard and 1.3% (w/w) cholesterol diet were randomly assigned to three groups. Two groups were treated with different dosages of a turmeric extract (A and B) and the third group (control) with a curcumin-free solution. Basal and in vitro 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced hydroperoxide and TBARS productions in liver mitochondria and microsomes were analyzed. Group A had the lowest concentration of mitochondrial hydroperoxides. In microsomes, the basal hydroperoxide levels were similar in all groups but, after the induction of oxidation, group C registered the highest value; TBARS production followed the same trend in mitochondria. These findings suggest that active compounds in curcuma extract may be protective in preventing lipoperoxidation of subcellular membranes in a dosage-dependent manner.

Animals↗

PubMed1998

Influence of dietary lipids on lipoprotein composition and LDL Cu(2+)-induced oxidation in rabbits with experimental atherosclerosis.

The aim of this study was to investigate the composition of plasma lipoproteins and their susceptibility to oxidation in rabbits with experimental atherosclerosis provoked by the intake of a diet rich in cholesterol and saturated fat as well as the influence of the intake of four diets differing in their lipid profiles (fish (F), refined olive (R), virgin olive (V) and sunflower (S) oils) on plasma lipoprotein composition and susceptibility to oxidation of these atherosclerotic rabbits. Plasma and lipoproteins concentrations of cholesterol, phospholipids and triglycerides were markedly higher in atherosclerotic rabbits but decreased with the experimental diets. LDL oxidation damage increased in atherosclerotic rabbits; the F diet led to a higher LDL oxidation susceptibility whereas groups fed either S, R, or V showed LDL oxidation values close to those of the control group. Diets rich in monounsaturated and n-3 polyunsaturated oils showed efficacy in restoring the normal lipid profiles in atherosclerotic rabbits provided in fish oil is adequately stabilized with antioxidants.

Animals↗

PubMed1998

Plasma antioxidants are strongly affected by iron-induced lipid peroxidation in rats subjected to physical exercise and different dietary fats.

Plasma is an important vehicle through which antioxidant molecules are conveyed and in which they may show different behaviors, either acting as a protective factor for oxidative damage to different blood elements or using it as a vehicle through which dietary antioxidant factors would be distributed to the body. The aim of the study was to determine the plasma level of vitamin E, coenzyme Q, uric acid and vitamin A and their relation with the cellular oxidative damage mediated by physical training and the ingestion of different fat (virgin olive and sunflower oils). Male Wistar rats were divided into 8 subgroups based on the dietary fat intake and their physical activity. Results show that both dietary fat and physical training affect susceptibility to iron-induced lipid peroxidation in plasma and the tissues that were studied. The increase of this lipid peroxidation parallels a decrease of the level of all the plasma antioxidants that were studied.

Animals↗

PubMed1998

Lipid peroxidation and antioxidants in erythrocyte membranes of full-term and preterm newborns.

The most probable factor connecting premature infant problems such as retinopathy, intraventricular hemorrhage and chronic lung disease appears to be the excessive production of oxygen free radicals which can occur as a consequence of oxygen therapy. The aim of our investigation was to elucidate the possible correlations between lipid peroxidation, in this study measured as hydroperoxides production, and antioxidant concentrations in erythrocyte membranes of both full term and preterm infants. Hydroperoxide concentrations were found to be high, especially in premature infants, in erythrocyte membranes at birth and in the initial days of life. The erythrocyte membranes were also found to contain low levels and/or low activities of antioxidant defense mechanisms which was more evident in premature newborns where alpha-tochopherol levels were significantly lower in comparison to full term infant levels. Furthermore, when premature infants undergo oxygen therapy these effects were exacerbated. These results demonstrate that at birth, particularly in the premature newborn, the degree of oxidative stress outweighs the antioxidant defense mechanisms.

Antioxidants↗

PubMed1997

Rabbit liver mitochondria coenzyme Q10 and hydroperoxide levels: an experimental model of atherosclerosis.

The development of the atherosclerosis is mediated by the accumulation of oxidized lipids in the arterial wall. There is a relationship between average intake of dietary fat, its quality, and incidence of atherosclerosis. The goal of this work was to study the effect of different dietary fats on the coenzyme Q10 and hydroperoxide content of liver mitochondria in rabbits affected by an induced atherosclerosis. The results show that the induction of experimental atherosclerosis leads to a significant increase in hydroperoxides of rabbit liver membrane mitochondria and to a significant drop in the content of CoQ10. Furthermore, treatment of atherosclerotic rabbits with different diets resulted in an increase of membrane hydroperoxides in the group fed sunflower oil whereas the increase was significantly lower for animals fed virgin olive oil and fish oil stabilized with vitamin E (1 g/kg). CoQ10 levels only recovered partially in all groups; however, values in the sunflower oil were significantly lower as compared to corresponding values of the other groups. The use of either virgin olive oil or vitamin E stabilized fish oil in the dietary treatment of atherosclerosis appears to be a valid alternative for maintaining adequate levels of CoQ10 and hydroperoxides in liver mitochondria.

Animals↗

PubMed1997

Renal metabolism of uric acid in type I insulin-dependent diabetic patients: relation to metabolic compensation.

Patients with insulin-dependent diabetes mellitus and poor glycemic control show hypouricemia with hyperuricosuria. In the present study, we have evaluated whether a good glycemic control influences the renal handling of uric acid. Sixteen patients (8 male, mean age 22.4 +/- 7.2 years) were studied under two situations, poor glycemic control (glycemia > 11 mmol/L and HbA1 c > 10%) and good glycemic control (glycemia < 6 mmol/L and HbA1 c < 8.5%). A group of 16 normal subjects served as the control group (8 male, mean age 21.9 +/- 9.1 years). In the poor glycemic control phase, patients showed lower plasma uric acid levels (0.18 +/- 0.06 mmol/L) and higher fractional urinary excretion of uric acid (16.1 +/- 9.3%) than the controls (0.28 +/- 0.06 and 8.2 +/- 1.9%, respectively). When a good glycemic control was reached, plasma uric acid increased (0.22 +/- 0.05), but it was still lower than that of the controls and fractional excretion of UA was normalized. Plasma uric acid was inversely correlated to glycemia (r = -0.34, p < 0.05) and to HbA1 c (r = -0.56, p < 0.0008) and fractional excretion of uric acid was directly correlated to glycemia (r = 0.39, p < 0.03) and HbA1 c (r = 0.73, p < 0.00005). These results indicate that the hypouricemia and hyperuricosuria of insulin-dependent diabetes mellitus is corrected by an adequate glycemic control, suggesting that these alterations are of a functional origin and due to a defective metabolic control.

Adolescent↗

PubMed1996

Absence of rapid adaptation of the exocrine pancreas of conscious dogs to diets enriched in fat or carbohydrates.

Adult mongrel dogs were fed during 8 days on one of two diets, one rich in fat (FR) and the other rich in carbohydrates (CR), in order to compare the exocrine pancreatic secretion in the basal period and in response to food. Under resting conditions, mean pancreatic juice flow and mean values of protein content, amylase and lipase activity and production were similar in both experimental groups, suggesting that the period of adaptation used did not produce any influence on the measured parameters. No significant difference between the two dietary groups was found in postprandial volume of pancreatic juice. The peak of pancreatic juice flow in FR-group was smaller but remained elevated until the end of the 5th h, possibly due to the fact of delayed gastric emptying when animals are fed with a high fat diet. No significant differences were found between the groups in neither postprandial amylase activity and secretion nor lipase activity. On the other hand, lipase output was significantly higher in FR-group but only during the 5 postprandial h. This fact may be related to some intestinal factor stimulated by the hydrolysis products of fat. Finally, our findings show that no rapid adaptation of exocrine pancreatic secretion exist to the diet, at least in our experimental conditions. Of course, this does not exclude that the phenomenon of adaptation may appear in the dog under long-term adaptation to the diet.

Adaptation, Physiological↗

PubMed1996

Dietary intake and anthropometric measures in a Spanish students group.

Two four-day diet records were used to estimate usual energy and nutrient intake, eating patterns (habits) and contribution of meals to total energy intake, in a group of 92 biology students from the Granada University. At the same time, a series of anthropometric measures was taken from each subject (weight, height, skin pleats and arm measurement). Comparison of real intakes with those recommended was carried out using the 1980 Spanish recommendations and the 1992 European Community recommendations. For men (n = 42) mean intakes for most nutrients were similar to the recommended levels and the proportion with intakes of vitamins and minerals below 80% of the recommended intakes was also minimal. Among women (n = 50) mean intake of zinc was below 80% of the Spanish recommendation. However, there was a wide range of intakes of minerals and vitamins within both groups; therefore, we found a high percentage of subjects with intakes of some vitamins or minerals below 80% of the recommended intakes. Finally, anthropometric measures showed normal body weight, height, and body composition among the students.

Adult↗