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Pharmacological and pharmaceutical properties of freeze-dried formulations of egg albumin, indomethacin, olive oil, or fatty acids.

Formulations consisting of egg albumin, indomethacin (IND), and olive oil or fatty acids, were prepared by vigorous stirring using a high-speed homogenizer and subsequent freeze-drying. To confirm the anti-inflammatory properties and ulcerogenic effects of the formulations, we examined the action of the formulations on carrageenan-induced edema in rats as well as their ulcerogenic actions in the same species. Compared with IND alone, albumin-IND-olive oil (9:1:4.3), albumin-IND-linolenic acid (9:1:4.3), albumin-IND-linolic acid (9:1:4.3), albumin-IND-oleic acid (9:1:4.3), albumin-IND-stearic acid (9:1:4.3), and albumin-IND-tristearin (9:1:4.3) formulations all exhibited a more potent inhibitory effect on carrageenan-induced edema. In addition, the inhibitory effects on edema formation of an albumin-IND (9:1) complex was as strong as that of IND alone. These results suggested that the bioavailability of IND was increased by olive oil, fatty acid, and tristearin as absorbefacient agents. The increase in the bioavailability was evident from the fact that the mean plasma levels, maximum plasma levels (Cmax), and area under plasma concentration-time curve (AUC) values after oral administration of the albumin-IND-olive oil (9:1:4.3) formulation was significantly greater than that after administration of the drug alone. With respect to their ulcerogenic properties, the formulations were significantly less active than IND alone, suggesting that a reduction in the ulcerogenic activity of IND was by produced complexation with egg albumin.

Administration, Oral↗

Consumption of olive oil and specific food groups in relation to breast cancer risk in Greece.

BACKGROUND: Experimental animal studies suggest that olive oil consumption, as contrasted to consumption of other fat types, does not enhance the occurrence of chemically induced mammary tumors, but human data are sparse. Furthermore, evidence is inconclusive concerning the role of food groups, as distinct from that of major nutrients, in the etiology of breast cancer in women. PURPOSE: This analysis was conducted to evaluate and quantify the effect of consumption of olive oil, margarine, and a range of food groups on the risk of breast cancer. METHODS: Data from a comprehensive, semiquantitative food-frequency questionnaire administered to 820 women with breast cancer and 1548 control women from the study base were used to calculate odds ratios (ORs) and X statistics of linear trend for the consumption of olive oil, margarine, and a series of food groups classified in quintiles. Adjustment for the effects of reproductive risk factors, energy intake, and mutual confounding influences was implemented through unconditional logistic regression modeling. RESULTS: Vegetable consumption and fruit consumption were independently associated with statistically significant reductions of breast cancer risk by 12% and 8%, respectively, per quintile increase; no significant associations were evident for the other food groups examined. Increased olive oil consumption was associated with significantly reduced breast cancer risk (OR = 0.75 [95% confidence interval = 0.57-0.98] for more than once a day versus once a day), whereas increased margarine consumption was associated with significantly increased risk (OR = 1.05 [95% confidence interval = 1.00-1.10] for an increment of four times a month). The olive oil association was apparently concentrated among postmenopausal women, but the relevant interaction term was not statistically significant; there was no suggestion of interaction with menopausal status for consumption of either vegetables, fruits, or margarine. CONCLUSIONS: Although major categories of macronutrients do not show significant associations with breast cancer risk in most studies, including the present one, vegetables and fruits are inversely, significantly, and strongly associated with this risk. There also is evidence that olive oil consumption may reduce the risk of breast cancer, whereas margarine intake appears to be associated with an elevated risk for the disease.

Breast Neoplasms↗

Effects of capsaicin on serum triglycerides and free fatty acid in olive oil treated rats.

Male rats were dosed with capsaicin after the administration of olive oil, and the serum was obtained for analysis of triglycerides and free fatty acids (FFAs). The serum triglycerides level was increased at 2 and 4 hours after olive oil treatment. On the other hand, capsaicin significantly lowered this increase after 4 hours of treatment in the dosage of 100 mg/kg. Total FFA level was also lowered which had previously been increased by the administration of olive oil after 2 hours of treatment, solely the increase in oleic acid (C18:1) levels was lowered among the FFA. The present results indicated that capsaicin decreased only the components of the dosed olive oil. Furthermore, elevation of the serum total FFA concentration was significantly inhibited 2 or 4 hours after the treatment but not at 8 hours, suggesting that a single high dose treatment with capsaicin may inhibit the absorption of lipid in the gastrointestinal tract.

Animals↗

Food and packaging interactions: determination of the kinetic parameters of olive oil diffusion in polypropylene using concentration profiles.

The penetration of olive oil into polypropylene was studied in order to allow a complete modellization of food and packaging interactions. Oil concentration profiles through polypropylene food trays were determined by FTIR-microscopy measurements along the thickness at various times. Calculations of the relevant parameters characterizing Fickian diffusion, namely constant diffusivity, coefficient of convective mass transport on the surface and concentration at equilibrium were carried out. This way of working has proven to be considerably shorter and more accurate than the method consisting of recording the global absorbance of the substance absorbed, especially when the amount of diffusing fat is low. Major conclusions are: that absorption of olive oil is strongly influenced by convection; the diffusion coefficient of olive oil in polypropylene is constant. Possible consequences to simplify global migration testing are discussed.

Diffusion↗

Lipolytic activity of Williopsis californica and Saccharomyces cerevisiae in extra virgin olive oil.

Inoculation trials performed with three strains of yeasts, isolated from extra virgin olive oil, Williopsis californica 1,639, Saccharomyces cerevisiae 1,525 and Candida boidinii 1,638, demonstrated that some yeast can lower the quality of the oil during storage. Laboratory tests highlighted a substantial increase in the total diglycerides and free fatty acids in the samples of oil inoculated with the lipase-producing strains of yeasts, W. californica 1,639 and S. cerevisiae 1,525, while in the samples of oil inoculated with the lipase-negative strain C. boidinii 1,638 no differences were found in respect to the uninoculated control. The acidity of the extra virgin olive oil, inoculated with the lipase-producing strains W. californica 1,639 and S. cerevisiae 1,525, during 2 weeks of incubation at 30 degrees C increased respectively from 0.62% to 1.50 and 1.62%, exceeding the limit of 0.8% established by current regulations for this commercial category of olive oil, while in the oil inoculated with the lipase-negative strain and in the uninoculated control, the acidity remained constant throughout. Furthermore, the two strains of lipase-producing yeasts also increased the concentration of the 1.3-diglyceride isomer in the oil lowering the values of the total 1.2-diglycerides/total 1.3-diglycerides ratio considered to be an important index of quality for an extra virgin olive oil. The lipolytic activity of lipase-producing strains W. californica 1,639 and S. cerevisiae 1,525 showed an optimum pH of 6 and 7.5 and an optimum temperature of 20 degrees C and 30 degrees C respectively. Nevertheless, the lipolytic activity was negatively influenced by glucose and polyphenols when the concentration was higher than 0.25% and 0.4% (wt/vol) respectively.

Candida↗

An epidemiological and an experimental study on the effect of olive oil on total serum and HDL cholesterol in healthy volunteers.

We have studied the effects of olive oil on serum lipids in a dietary experiment with 48 healthy adult Dutch volunteers and in 76 boys 8-10 years of age from rural Crete. The dietary trial was carried out with normolipidaemic subjects, and it compared the effects of an olive-oil-rich and a carbohydrate-rich, high-fibre diet on serum lipids. Replacement of 12% of energy (en%) from saturated fatty acids by either monounsaturates or complex carbohydrates caused the same fall in serum total cholesterol of 0.45 mmol 1(-1). HDL cholesterol levels fell by 0.19 mmol 1(-1) on the carbohydrate-rich diet, but remained virtually unchanged on the olive-oil-rich diet. This was in agreement with our hypothesis that the total amount of fat in the diet is a determinant of HDL cholesterol. The diet of the Cretan boys contained 10 en% saturated fat, but 27 en% monounsaturated fat due to the liberal use of olive oil. Serum-lipid levels of the Cretan boys were not different from those of their counterparts from western European Countries. The mean body mass index of the Cretan boys was about 2 kg m-2 higher than those of boys in the other countries, which might have confounded comparisons. Whatever the explanation, the present-day lifestyle and diet in Crete do not produce a particularly favourable HDL to LDL cholesterol ratio in the blood, even though olive oil intake is high.

Child↗

Stability of virgin olive oil. 2. Photo-oxidation studies.

Virgin olive oil samples with similar oxidative stabilities and fatty acid compositions were exposed to 12100 lx (25 +/- 1 degrees C) in closed bottles until bleached. The observed low changes in the substrate and polar phenols were related to oxygen availability. HPLC monitoring showed that pheophytin agradual degradation (> 90%) was accompanied by a considerable alpha-tocopherol loss (22-35%) due to the reaction of the latter with singlet oxygen. No changes were recorded for carotenoids, which acted as physical quenchers and light filters. Squalene loss was confined (4-12%). Complementary experiments on the activity of pheophytin a, using olive oil models, indicated a concentration dependence, enhanced by oxygen availability. In closed bottles, the degradation rate constant was higher at low amounts of pheophytin a. Squalene was preferentially consumed to protect alpha-tocopherol. An urgent change in the practice of packaging is needed to preserve the precious characteristics of the product during commercialization.

Chlorophyll↗

Mixture of honey, beeswax and olive oil inhibits growth of Staphylococcus aureus and Candida albicans.

BACKGROUND: Honey, beeswax and olive oil mixture (1:1:1, v/v) is useful in the treatment of diaper dermatitis, psoriasis and eczema. The study was designed to investigate effects of honey, olive oil, and beeswax and the mixture on growth of Staphylococcus aureus and Candida albicans isolated from human specimens. METHODS: The following experiments were performed: 1) honey mixture was poured on holes made on plates seeded with S. aureus or C. albicans, 2) the microorganisms were cultured onto media made of honey mixture alone, nutrient agar-honey mixture and Sabouraud glucose agar-honey mixture. The concentration of honey mixture in nutrient agar or Sabouraud glucose agar was 12.5, 25, 33, 50 and 66% (v/v), and 3) honey, olive oil or beeswax was added onto nutrient agar or Sabouraud glucose agar at a ratio of 1:2 (v/v) and then were seeded with S. aureus or C. albicans. RESULTS: Clear zone of inhibition was observed around holes filled with honey mixture; 3.5 mm on media seeded with C. albicans and 4 mm on media seeded with S. aureus. No growth of either microorganism was obtained on media made of honey mixture alone. The minimum concentration of honey mixture in nutrient agar-honey mixture media required to inhibit S. aureus was 50% and 66% concentration was required to inhibit C. albicans growth onto Sabouraud glucose agar-honey mixture media. No growth of S. aureus or C. albicans was obtained on media containing honey whereas mild to moderate growth was obtained on media containing olive oil or beeswax. CONCLUSIONS: Honey and honey mixture apparently could inhibit growth of S. aureus or C. albicans.

Animals↗

Rapid and quantitative extraction method for the determination of chlorophylls and carotenoids in olive oil by high-performance liquid chromatography.

Colour is an organoleptic characteristic of virgin olive oil and an important attribute that affects the consumer perception of quality. Chlorophylls and carotenoids are the main pigments responsible for the colour of virgin olive oil. A simple analytical method for the quantitative determination of chlorophylls and carotenoids in virgin olive oils has been developed. The pigments were isolated from small samples of oil (1.0 g) by solid-phase extraction using diol-phase cartridges (diol-SPE), and the extract was analysed by reverse-phase HPLC with diode-array UV detection. Chromatographic peak resolution, reproducibility (coefficient of variation (C.V.) <4.5%) and recovery (>98.4%) for each component were satisfactory. A comparative study of the proposed method was performed versus classical liquid-liquid extraction (LLE) with N,N'-dimethylformamide and solid-phase extraction using a C18 column (C18-SPE). While 96.4% of the pigments were recovered by LLE, only 51.3% were isolated by C18-SPE in comparison to diol-SPE. Likewise, a higher alteration of pigment composition was observed when such LLE and C18-SPE procedures were used. In this sense, a higher ratio of pheophytin in comparison to that isolated by the diol-SPE procedure was achieved with both extraction procedures, indicating a greater extent of the pheophytinization reaction. Therefore, quantification of pigments from virgin olive oil by diol-SPE followed by RP-HPLC was found to be rapid, simple, required only a small amount of sample, consumed only small amounts of organic solvents, and provided high recoveries, accuracy and precision.

Carotenoids↗

Effects of olive oil on superoxide dismutase activity in the brain of newborn and young female rats.

Changes in the activity of brain antioxidant superoxide dismutases (SOD) were followed in newborn and young female rats 8, 15, 30, 45, 60 and 75 days after birth treated with olive oil. In newborn rats, the content of brain cytosol SOD (CuZnSOD) and mitochondrial SOD (MnSOD) decreased after treatment with olive oil. However, in the brain of rats aged 8 days this effect was lost. The suppressive effect of olive oil on these enzymes reappeared again in 15-day-old rats. In rats aged one month, only the activity of CuZnSOD was reduced after olive oil treatment. In the brain of rats aged 45, 60 and 75 days, neither MnSOD nor CuZnSOD were affected by olive oil. The different effects of olive oil on the brain SOD, during ontogeny suggest that profound changes in the susceptibility of nervous tissue antioxidant enzymes to olive oil take place during sexual maturation.

Animals↗

A case report of possible health benefits of extra virgin olive oil.

The literature on the chemical analysis of cooking oils suggests that the cholesterol-reducing effect may well be due to the antioxidant agents rather than unsaturated fats. Furthermore, antioxidant agents are present in extra virgin olive oil and not in olive oil. There is some evidence, based on studies using patients, to support such a supposition. In this paper, we present a case report on the possible health effects of changing from olive oil to extra virgin olive oil. The case report is intended to raise some relevant issues to stimulate a debate and more research in this area.

Cholesterol↗

Dietary factors in relation to rheumatoid arthritis: a role for olive oil and cooked vegetables?

BACKGROUND: Although several studies showed that risk of rheumatoid arthritis (RA) is inversely associated with consumption of n-3 fatty acids, the one study showing that olive oil may have a protective role has not yet been confirmed. OBJECTIVE: We examined the relation between dietary factors and risk of RA in persons from southern Greece. DESIGN: We studied 145 RA patients and 188 control subjects who provided information on demographic and socioeconomic variables, prior medical and family history, and present disease status. Subjects responded to an interviewer-administered, validated, food-frequency questionnaire that assessed the consumption of >100 food items. We calculated chi-square statistics for linear trend and odds ratios (ORs) for the development of RA in relation to the consumption of olive oil, fish, vegetables, and a series of food groups classified in quartiles. RESULTS: Risk of developing RA was inversely and significantly associated only with cooked vegetables (OR: 0.39) and olive oil (OR: 0.39) by univariate analysis. A significant trend was observed with increasing olive oil (chi-square: 4.28; P = 0.03) and cooked vegetable (chi-square: 10. 48; P = 0.001) consumption. Multiple logistic regression analysis models confirmed the independent and inverse association between olive oil or cooked vegetable consumption and risk of RA (OR: 0.38 and 0.24, respectively). CONCLUSIONS: Consumption of both cooked vegetables and olive oil was inversely and independently associated with risk of RA in this population. Further research is needed to elucidate the underlying mechanisms of this finding, which may include the antioxidant properties or the high n-9 fatty acid content of the olive oil.

Adolescent↗

Soybean- and olive-oils-enriched diets increase insulin secretion to glucose stimulus in isolated pancreatic rat islets.

Islets isolated from rats fed a lipid-enriched diet have shown an impairment of insulin secretion, but there is no available data comparing the effect of diet containing different dietary fat. This may be important in preventing or facilitating the establishment of diabetes. In this study, the effect of diets enriched (10%) with different fatty acids on insulin secretion by isolated pancreatic islets was investigated. The sources of the fatty acids tested were: saturated long chain from animal fat (AF), polyunsaturated from soybean oil (SO), and monounsaturated from olive oil (OL). The results were compared with those from rats receiving a diet enriched (10%) with a balanced mixture of fatty acids (the same proportion of AF, SO, and OL). The effect of fat-rich diets on insulin release was tested in vivo by giving a glucose load (glucose tolerance test-GTT) and in vitro in perfused islets. The mechanism involved was also examined by measuring 45Ca2+ and 86Rb+ fluxes, GLUT-2 content, and glucose oxidation in isolated islets. A significant increase of insulin secretion and glucose oxidation without any alteration of the ionic movements were detected in islets from SO and OL rats. GLUT-2 content was increased in islets of the OL group but diminished in AF rats. The results led us to postulate that soybean and olive oils may increase the response of insulin secretion to glucose stimulus in pancreatic islets.

Animals↗

Moderate consumption of olive oil by healthy European men reduces systolic blood pressure in non-Mediterranean participants.

We evaluated the effects of a moderate consumption of olive oil on lipid profile, BMI, and blood pressure (BP) in a group of 160 healthy men from non-Mediterranean regions [Northern Europe (n = 50; Finland and Denmark) and Central Europe (n = 60; Germany)] and Mediterranean regions [Southern Europe (n = 45; Italy and Spain)]. The study was a randomized, cross-over trial with 3 intervention periods of 3 wk and 2 wash-out periods of 2 wk. At the intervention periods, 3 similar olive oils (25 mL/d), differing only in their phenolic concentration, were administered to the healthy volunteers. Plasma oleic acid levels increased 2-3% (P < 0.05) in men from populations with lower habitual olive oil intakes (Northern and Central Europe). General linear models showed that the administration of the sequence of the 3 olive oils was responsible for a 3% decrease in systolic BP (SBP) (P < 0.05), but not in diastolic BP, in the non-Mediterranean subjects. Multivariate analysis indicated that the lipid profile did not change in either Mediterranean or non-Mediterranean men due to the olive oil intervention. The results of this study suggest that a moderate consumption of olive oil may be used as an effective tool to reduce SBP of healthy men who do not typically consume a Mediterranean diet. However, additional longer trials are necessary for confirmation.

Adult↗

Influence of rosemary (Rosmarinus officinalis, L.) on plant sterol oxidation in extra virgin olive oil.

The objective of this study was to investigate the potential role of rosemary compounds in inhibiting the plant sterol oxidation in extra virgin olive oil during heating. The stability of plant sterols was measured by quantification of plant sterol and sterol oxide formation upon 6 h of heating in both the extra virgin olive oil and its respective oil at 10% rosemary concentration (ROE). The total sterol and sitosterol oxide contents were determined by GC-flame ionization detection (GC-FID) and GC-MS techniques, respectively. Heating experiments were carried out at 180 degrees C for 0, 1, 3 and 6 h. The total sterol content in the extra virgin olive oil was 255 mg/100 g and that in the ROE 270 mg/100 g. Sitosterol was the most abundant sterol in both samples (50% of total sterol). The ROE showed a lower content of sitosterol oxides with respect to the extra virgin olive oil during heating: after 6 h of heating only 6.1% of sitosterol oxides were formed, while up to 11.5% of sitosterol oxidized in the extra virgin olive oil. Our findings suggested that rosemary compounds were able to counteract the oxidation of plant sterols in the extra virgin olive oil during heating, preventing formation of potentially harmful compounds to human health.

Antioxidants↗

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.

Analysis of Variance↗

[Pregnant rats consuming diets with uncooked and fried olive oil, mineral levels in their offspring and changes in their body storage levels].

Some parameters relating nutritional utilization of Ca, Mg, Fe and Zn were studied in rats fed with diets including raw and fried fats in order to study more in depth the diet fat/mineral utilization interaction. Wistar rats having initial weights of 176 g were divided into two groups and fed isocaloric diets having 15% fat content as raw olive oil and fried olive oil (from 15 potato fryings), during pregnancy. Weight and dietary intake were controlled and mineral content changes in plasma, liver, spleen and carcass were assessed, as well as litter mineral uptake. Throughout the study, dietary intake of pregnant rats fed raw (R) and fried oil (F), body weight gain and final weight gain were similar. Serum Fe, Zn and Ca levels decreased at a similar rate in both groups. Liver Fe levels decreased more in the F group while spleen Fe decreased more in the R group, these changes started on day 18. Liver Zn levels did not show clear changes but spleen Zn decreased during the last three days of pregnancy. Carcass Ca levels of pregnant rats from the R and F groups did not show any differences at the end of pregnancy. Body weight gain, Ca, Mg, Fe and Zn uptake of the litter were similar in both groups throughout the study. The placentas and the offspring of treated rats showed similar absolute and relative mineralization values. These findings lead us to conclude that fried olive oil retained the same characteristics as raw olive oil regarding mineral utilization.

Animals↗

Effects of olive oil and its minor constituents on serum lipids, oxidative stress, and energy metabolism in cardiac muscle.

Recent lines of evidence suggest that the beneficial effects of olive oil are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. The aim of this work was determine the effects of olive oil and its components, oleic acid and the polyphenol dihydroxyphenylethanol (DPE), on serum lipids, oxidative stress, and energy metabolism on cardiac tissue. Twenty four male Wistar rats, 200 g, were divided into the following 4 groups (n = 6): control (C), OO group that received extra-virgin olive oil (7.5 mL/kg), OA group was treated with oleic acid (3.45 mL/kg), and the DPE group that received the polyphenol DPE (7.5 mg/kg). These components were administered by gavage over 30 days, twice a week. All animals were provided with food and water ad libitum. The results show that olive oil was more effective than its isolated components in improving lipid profile, elevating high-density lipoprotein, and diminishing low-density lipoprotein cholesterol concentrations. Olive oil induced decreased antioxidant Mn-superoxide dismutase activity and diminished protein carbonyl concentration, indicating that olive oil may exert direct antioxidant effect on myocardium. DPE, considered as potential antioxidant, induced elevated aerobic metabolism, triacylglycerols, and lipid hydroperoxides concentrations in cardiac muscle, indicating that long-term intake of this polyphenol may induce its undesirable pro-oxidant activity on myocardium.

Animals↗