Impaired platelet aggregation and thromboxane generation in essential fatty acid-deficient rats

ADP-induced platelet aggregation and thrombin-induced thromboxane B2 generation in diluted whole blood from rats fed a fat-free diet supplemented with 10% (by weight) hydrogenated coconut oil [essential fatty acid (EFA) deficient] were significantly lower than that in animals fed 10% safflower oil [(SFO) rich in linoleic acid] or 10% marine oil (rich in eicosapentaenoic acid and docosahexaenoic acid). Plasma fibrinogen levels were significantly lower and liver function was impaired in the EFA-deficient group compared with the other two groups. Platelet responsiveness to ADP was restored when plasma from the EFA-deficient rats was replaced by plasma obtained from rats fed a nonpurified diet. ADP responsiveness and thrombin-stimulated thromboxane B2 production in diluted whole blood were also restored after 2 wk of injections of 100 mg ethyl linoleate every 48 h, and partially restored by injections of 100 mg ethyl alpha-linolenate. When ADP-induced platelet aggregation was examined in washed platelets, the impaired ADP aggregation (found when platelets of the EFA-deficient rats were suspended in their own plasma) was not observed at either high (9.5 microM) or low (1.0 microM) ADP concentrations. Although thrombin-stimulated thromboxane B2 production in washed platelets in the EFA-deficient rats was lower than that in the SFO-fed rats, the magnitude of aggregation was not different. In addition, inhibition of thrombin-induced platelet aggregation by apyrase (0.06 U/mL) was identical in the two groups. These results suggest that impaired platelet aggregation in EFA deficiency is related more to plasma factors than to inherent platelet properties and that restoration of normal liver function is associated with normal platelet function.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bioavailability of phenols from a phenol-enriched olive oil

Phenolic compounds are one of the main reasons behind the healthy properties of virgin olive oil (VOO). However, their daily intake from VOO is low compared with that obtained from other phenolic sources. Therefore, the intake of VOO enriched with its own phenolic compounds could be of interest to increase the daily dose of these beneficial compounds. To evaluate the effectiveness of enrichment on their bioavailability, the concentration of phenolic compounds and their metabolites in human plasma (0, 60, 120, 240 and 300 min) from thirteen healthy volunteers (seven men and six women, aged 25 and 69 years) was determined after the ingestion of a single dose (30 ml) of either enriched virgin olive oil (EVOO) (961·17 mg/kg oil) or control VOO (288·89 mg/kg oil) in a cross-over study. Compared with VOO, EVOO increased plasma concentration of the phenol metabolites, particularly hydroxytyrosol sulphate and vanillin sulphate (P < 0·05). After the consumption of VOO, the maximum concentration of these peaks was reached at 60 min, while EVOO shifted this maximum to 120 min. Despite these differences, the wide variability of results indicates that the absorption and metabolism of olive oil phenols are highly dependent on the individual.     

牛磺酸对糖尿病大鼠血糖和血小板聚集的影响

目的　观察牛磺酸 (taurine,Tau)对糖尿病大鼠血糖、血小板计数、血小板聚集功能以及血小板中氧自由基代谢的影响。方法　在以链佐霉素诱导的糖尿病大鼠模型上 ,测定血糖以及二磷酸腺苷 (ADP)、凝血酶 (Thr)诱导的血小板最大聚集率、血小板计数、血小板中超氧化歧化酶 (SOD)的活性、丙二醛 (MDA)的含量。结果　糖尿病大鼠的血糖、以 ADP、Thr诱导的血小板最大聚集率明显高于正常组 ;血小板中 SOD活性及血小板计数下降、MDA含量升高。Tau治疗后糖尿病大鼠的血糖显著降低 ;血小板计数、血小板中 SOD的活性、MDA的含量及 ADP、Thr诱导的血小板最大聚集率无显著改变。结论　糖尿病大鼠血小板聚集功能增强可能与血小板中氧自由基代谢异常有关。Tau能降低糖尿病大鼠的血糖 ,但对其血小板功能和血小板中氧自由基的代谢无明显的影响。     

Hypolipidimic and antioxidant activities of virgin olive oil and its fractions in 2,4-diclorophenoxyacetic acid-treated rats

Objective

We examined the effects of extra virgin olive oil (EVOO) and its hydrophilic and lipophilic fractions on serum lipids, oxidative stress, and morphologic and functional liver damages induced by 2,4-diclorophenoxyacetic acid (2,4-D).

Methods

Male Wistar rats were divided randomly into eight groups: control; 2,4-D at a dose of 5 mg/kg of body weight (2,4-D); 2,4-D plus EVOO (2,4-D/EVOO); 2,4-D plus the hydrophilic fraction (2,4-D/OOHF); 2,4-D plus the lipophilic fraction (2,4-D/OOLF); only EVOO (EVOO); only the hydrophilic fraction (OOHF); and only the lipophilic fraction (OOLF). These components were administered daily by gavage for 4 wk.

Results

A hepatic architecture aberration, increased activities of aspartate and alanine aminotransferase enzymes, total and low-density lipoprotein cholesterol, and malondialdehyde (MDA) level, and a decreased antioxidant defense system were observed in the 2,4-D group. The administration of EVOO restored the damage caused by 2,4-D by a significant decrease of plasma total and low-density lipoprotein levels and a moderate increase of high-density lipoprotein cholesterol. The 2,4-D/OOHF group exhibited a pronounced enhancement of the antioxidant defense system by an increase of superoxide dismutase, catalase, and glutathione peroxidase levels and a decrease of plasma and liver MDA levels. However, less improvement in the liver histoarchitecture and antioxidant status was observed in rats supplemented with OOLF diet, despite its richness in α-tocopherol.

Conclusion

Extra virgin olive oil may be a potential functional food source of antioxidants than can decrease the frequency of cardiovascular diseases and liver damage.     

Attitudes towards Olive Oil Usage,Domestic Storage,and Knowledge of Quality: A Consumers’ Survey in Greece

Consumption of unbranded olive oil obtained in bulk has previously been reported to be very high in Greece, underlining the need to investigate knowledge regarding its health attributes and storage practices, two areas that can affect oil quality. This study aimed to investigate Greek consumers’ use and choice of olive oil, their knowledge about its quality, as well as domestic storage practices of olive oil. A cross-sectional survey was conducted in a representative sample of 857 Greek households that consume olive oil, using a previously validated questionnaire. Most participating households use olive oil produced by themselves or by their extended family or friends (60.3%), and only 27.4% purchase branded olive oil, while 57% reported using extra virgin olive oil (EVOO). Only 38.4% of the respondents reported optimal domestic storage practices to maintain olive oil quality, with a significant greater percentage of non-producers group compared to olive oil producers. In all areas of Greece, the higher the knowledge of olive oil quality, the higher the probability of consumers selecting EVOO and perceiving olive oil price as low. The present survey highlights the need to heighten consumers’ knowledge of olive oil attributes and correct storage practices and awareness about branded EVOO and its superior quality.     

Olive oil reduces oxidative damage in a 3-nitropropionic acid-induced Huntington's disease-like rat model

Free radicals contribute to altered neuronal functions in neurodegenerative diseases and brain aging, by producing lipid- and other molecule-dependent modifications. The Mediterranean diet has been associated with a reduced risk of neurodegenerative disease. This study sought to verify whether extra-virgin olive oil (EVOO) exerted a brain antioxidant effect, protecting the brain against the oxidative stress caused by 3-nitropropionic acid (3NP). 3NP was administered intraperitoneally (i.p.) at a dose of 20 mg/kg body weight over four consecutive days. EVOO (representing 10% of calorie intake in the total standard daily diet of rats) and hydroxytyrosol (HT; 2.5 mg/kg body weight) were administered for 14 days. In all studied samples, 3NP caused a rise in lipid peroxides (LPO) and a reduction in glutathione (GSH) content. While the results showed that EVOO and HT reduces lipid peroxidation product levels and blocks the GSH depletion prompted by 3NP in both striatum and rest of the brain in Wistar rats. In addition, EVOO blocks and reverses the effect of 3NP on succinate dehydrogenase activity. In brief, the data obtained indicate that EVOO and HT act as a powerful brain antioxidant.     

Serum lipid profile and inflammatory markers in the aorta of cholesterol-fed rats supplemented with extra virgin olive oil,sunflower oils and oil-products

Abstract

Extra virgin olive oil (EVOO) major and minor component anti-inflammatory effect on aorta was evaluated; Wistar rats were fed (9 weeks) on either a high-cholesterol diet (HCD) or a HCD supplemented with oils, i.e. EVOO, sunflower oil (SO), high-oleic sunflower oil (HOSO), or oil-products modified to their phenolic content, i.e. phenolics deprived-EVOO [EVOO(?)], SO enriched with the EVOO phenolics [SO(+)], HOSO enriched with the EVOO phenolics [HOSO(+)]. HCD induced dyslipidemia and resulted in higher aorta adhesion molecules levels at euthanasia. Groups receiving EVOO, EVOO(?), HOSO, HOSO(+) presented higher serum TC and LDL-c levels compared to cholesterol-fed rats; attenuation of aorta E-selectin levels was also observed. In EVOO/EVOO(?) groups, aorta vascular endothelial adhesion molecule-1 (VCAM-1) was lower compared to HCD animals. SO/SO(+) diets had no effect on endothelial dysfunction amelioration. Overall, our results suggest that major and/or minor EVOO constituents improve aorta E-selectin and VCAM-1, while serum lipids do not benefit.     

Virgin Olive Oil Study (VOLOS): vasoprotective potential of extra virgin olive oil in mildly dyslipidemic patients

Summary Background In vitro, olive phenols exert potent antioxidant and enzyme-modulating activities. Aim of the study We comparatively evaluate, in mildly dyslipidemic patients, the vasoprotective potential of extra virgin olive oil. Methods 22 patients were administered 40 mL/day of either extra-virgin, i. e. phenol rich, or refined, i. e. phenol poor, olive oils (EVOO or ROO, respectively, with nearly identical fatty acid composition), with a crossover design. Each treatment was carried out for seven weeks, with four weeks of washout in between. Plasma antioxidant capacity, serum thromboxane B₂ (TXB₂) formation, and urinary isoprostane excretion were evaluated as surrogate markers of cardioprotective potential and vascular function. Results No effects on plasma lipid/lipoprotein profile were observed. Conversely, EVOO consumption was associated with favorable effects on circulating markers. Namely, decreased serum TXB₂ production and increased plasma antioxidant capacity were observed when EVOO was administered in both treatment arms. Neither treatment had any significant effect on isoprostane excretion. Conclusions EVOO consumption by mildly dyslipidemic patients is associated with favorable changes in circulating markers of cardiovascular condition. Based on current knowledge, these effects may be associated with cardioprotection.     

Olive oil reduces oxidative damage in a 3-nitropropionic acid-induced Huntington's disease-like rat model

Abstract

Free radicals contribute to altered neuronal functions in neurodegenerative diseases and brain aging, by producing lipid- and other molecule-dependent modifications. The Mediterranean diet has been associated with a reduced risk of neurodegenerative disease. This study sought to verify whether extra-virgin olive oil (EVOO) exerted a brain antioxidant effect, protecting the brain against the oxidative stress caused by 3-nitropropionic acid (3NP). 3NP was administered intraperitoneally (i.p.) at a dose of 20 mg/kg body weight over four consecutive days. EVOO (representing 10% of calorie intake in the total standard daily diet of rats) and hydroxytyrosol (HT; 2.5 mg/kg body weight) were administered for 14 days. In all studied samples, 3NP caused a rise in lipid peroxides (LPO) and a reduction in glutathione (GSH) content. While the results showed that EVOO and HT reduces lipid peroxidation product levels and blocks the GSH depletion prompted by 3NP in both striatum and rest of the brain in Wistar rats. In addition, EVOO blocks and reverses the effect of 3NP on succinate dehydrogenase activity. In brief, the data obtained indicate that EVOO and HT act as a powerful brain antioxidant.     

不同类型脂肪对高脂血家兔动脉粥样硬化形成的影响

本文观察了饱和脂肪(猪油)、单不饱和脂肪(橄揽油)和ω—3多不饱和脂肪(鱼油)对高脂血家兔血脂、血小板聚集、体外血栓形成及动脉粥样硬化(AS)形成的影响。雄性大耳家兔分为:猪油组、橄榄油组和鱼油组,每组9只。实验3个月期间各组每天每只分别给予猪油、橄榄油和鱼油2ml(内含胆固醇0.5g和维生素E10mg)。猪油组血清总胆固醇(TC)明显高于橄榄油组和鱼油组(P<0.01),后两组无显著差异;鱼油组血小板聚集率和血栓干重显著低于橄榄油组;鱼油组血浆过氧化脂质水平明显高于另两组;橄榄油组不仅血浆过氧化脂质水平低,且主动脉AS斑块面积亦显著低于另两组;鱼油组AS斑块面积小于猪油组,但无显著差异。     

Influence of oryzanol on platelet aggregation in rats

Platelet aggregation was measured using platelet rich plasma prepared from rats fed oryzanol in the control diet and those fed oryzanol in a 1 per cent cholesterol diet (HCD). Oryzanol with the control diet did not alter platelet aggregation induced by ADP and collagen. On the other hand, oryzanol fed along with HCD significantly inhibited platelet aggregation induced by ADP and totally inhibited aggregation induced by collagen.     

Inhibiting effect of desalted extract from Galega officinalis L. on platelet aggregation.

The inhibiting and disaggregating effect of desalted and fractionated herbal extract of Galega officinalis L. on platelet aggregation in vitro is studied. At a concentration of 35 micrograms/ml in a platelet-rich plasma (PRP) the fraction inhibits 50% of aggregation by ADP and at 125 micrograms/ml PRP it inhibits fully the aggregation of PRP by ADP. At a concentration of 40 micrograms/ml PRP the fraction inhibits the initiation of platelet aggregation by collagen and at 50 micrograms/ml PRP inhibits the initiation of aggregation by thrombin. At a concentration of 65 micrograms/ml PRP the fraction can disaggregate 50% of the aggregated platelet-rich plasma by ADP and 25% of aggregated PRP by collagen.     

Docosahexaenoic acid decreases plasma homocysteine via regulating enzyme activity and mRNA expression involved in methionine metabolism

ObjectiveThe objective of this study was to investigate the regulatory effect of fish oil rich in ω-3 polyunsaturated fatty acids (PUFAs) on critical enzyme activity and mRNA expression involved in homocysteine (Hcy) metabolism.MethodsThirty-six male Sprague-Dawley rats aged 3 wk, weighing 120 ± 10 g, were randomly divided into three groups: the olive oil (OO) group, the tuna oil (TO) group, and the salmon oil (SO) group. The oil was orally administered every day using a stomach tube. Eight weeks later, plasma Hcy, phospholipids, ω-3 PUFAs, enzyme activity, and mRNA expression in tissues were determined.ResultsCompared with the control group, phospholipids, total ω-3 PUFAs, and ω-3/ω-6 PUFAs in the liver and lung were significantly elevated in the TO and SO groups; 22:6ω-3 in the liver and lung was significantly increased in the TO group; and 20:5ω-3 in the two tissues was significantly elevated in the SO group. The level of plasma Hcy was significantly decreased with TO; methionine adenosyl transferase (MAT) activity was significantly increased and MAT mRNA expression was significantly upregulated with TO; cystathionine-γ-lyase mRNA expression in TO was significantly upregulated; however, cystathionine β-synthase and S-adenosylhomocysteine hydrolases were not significantly changed when compared with control.ConclusionTO rich in 22:6ω-3 decreases the concentration of Hcy despite increasing MAT activity and upregulating MAT mRNA expression through compensatory cystathionine-γ-lyase mRNA expression, both of which are involved in Hcy metabolism.     

浓缩鱼油对兔血小板聚集和凝血时间及组织脂肪酸含量的影响

本文观察兔给予浓缩鱼油后血小板聚集和凝血时间及组织脂肪酸含量的变化。27头雄性青紫兰兔分为三组(橄榄油对照组、鱼油Ⅰ组和鱼油Ⅱ组)。鱼油Ⅰ组以灌胃法给予浓缩鱼油2ml/天/头,鱼油Ⅱ组以同法给予4ml/天/头,对照组给予橄榄油4ml/天/头,实验期均为10周。结果表明,与对照组相比,鱼油Ⅰ、Ⅱ组的血小板聚集率明显降低(P<0.001),凝血时间显著延长(P<0.001)。鱼油组动物的血浆、血小板、心肌及主动脉均含廿碳五烯酸(EPA)和廿二碳六烯酸(DHA),这些组织的(ω-3/ω-6族脂肪酸的比值明显高于对照组,脂肪酸分布的模式与实验动物的血小板聚集率及凝血时间的变化吻合。     

Microencapsulated krill and tuna oil blend raises plasma long-chain n-3 polyunsaturated fatty acid levels compared to tuna oil with similar increases in ileal contractility in rats

Long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may be more bioavailable from krill oil compared to fish oil due to their phospholipid structure. We tested whether a microencapsulated krill and tuna oil blend (ME-TOKO) provided greater LC n-3 PUFA bioavailability, improved blood lipid profiles and increased intestinal contractility compared to microencapsulated tuna oil (ME-TO). Rats were divided into three groups to receive isocaloric diets containing ME-TO, ME-TOKO and microencapsulated olive oil (ME-OO) at 0.3 or 2?g/100?g for 4 weeks. Final body and organ weights, feed intake and waste output were similar. ME-TOKO rats had higher plasma total LC n-3 PUFA levels compared to ME-TO, but liver LC n-3 PUFA levels and plasma triglyceride and cholesterol levels were similar in non-fasted rats. Diets containing 2% ME-TO and ME-TOKO also showed similar increases in ileal contractility. In summary, ME-TO bioavailability of LC n-3 PUFA was similar to ME-TOKO.     

Olive oils high in phenolic compounds modulate oxidative/antioxidative status in men

The aim of the present study was to evaluate whether olive oils high in phenolic compounds influence the oxidative/antioxidative status in humans. Healthy men (n = 12) participated in a double-blind, randomized, crossover study in which 3 olive oils with low (LPC), moderate (MPC), and high (HPC) phenolic content were given as raw doses (25 mL/d) for 4 consecutive days preceded by 10-d washout periods. Volunteers followed a strict very low-antioxidant diet the 3 d before and during the intervention periods. Short-term consumption of olive oils decreased plasma oxidized LDL (oxLDL), 8-oxo-dG in mitochondrial DNA and urine, malondialdehyde in urine (P < 0.05 for linear trend), and increased HDL cholesterol and glutathione peroxidase activity (P < 0.05 for linear trend), in a dose-dependent manner with the phenolic content of the olive oil administered. At d 4, oxLDL after MPC and HPC, and 8-oxo-dG after HPC administration (25 mL, respectively), were reduced when the men were in the postprandial state (P < 0.05). Phenolic compounds in plasma increased dose dependently during this stage with the phenolic content of the olive oils at 1, 2, 4, and 6 h, respectively (P < 0.01). Their concentrations increased in plasma and urine samples in a dose-dependent manner after short-term consumption of the olive oils (P < 0.01). In conclusion, the olive oil phenolic content modulated the oxidative/antioxidative status of healthy men who consumed a very low-antioxidant diet.     

Olive oil isochromans inhibit human platelet reactivity

The effects of certain polyphenolic compounds in red wine, such as resveratrol and quercetin, have been widely investigated to determine the relationship between dietary phenolic compounds and the decreased risk of cardiovascular diseases. However, the effects of polyphenolic compounds contained in other foods, such as olive oil, have received less attention and little information exists regarding the biological activities of the phenol fraction in olive oil. The aim of this study was to evaluate the antiplatelet activity and antioxidant power of two isochromans [1-(3'-methoxy-4'-hydroxy-phenyl)-6,7-dihydroxy-isochroman (encoded L116) and 1-phenyl-6,7-dihydroxy-isochroman (encoded L137)] recently discovered in olive oil and synthesized in our laboratory from hydroxytyrosol. These compounds were effective free radical scavengers and inhibited platelet aggregation and thromboxane release evoked by agonists that induce reactive oxygen species-mediated platelet activation including sodium arachidonate and collagen, but not ADP. Release of tritiated arachidonic acid from platelets was also impaired by L116 and L137. These results indicate that other Mediterranean diet nutraceuticals also exhibit antioxidant activity that could be beneficial in the prevention of vascular diseases.     

富含EPA浓缩鱼油抑制血小板聚集的机理探讨

流行病学和实验室资料均提示富含EPA鱼油(简称鱼油)具有抑制血小板聚集和抗血栓形成的作用。本文主要探讨鱼油抑制血小板聚集的机理。实验分别将大鼠和家兔随机分成4组:正常组、高脂组、鱼油组、橄榄油组。按各自不同饲料喂养3个月以后,4组大鼠血浆TXB_2/6-酮-PGF_(1a)比值分别为1.4,2.2,1.0,1.7。鱼油组血小板内cAMP含量明显高于高脂组(P<0.05)。鱼油组血清总胆固醇值、血浆TXB_2、5-羟色胺(5-HT)、钙离子浓度、纤维蛋白原含量及血液粘度(低切)均明显低于高脂组(P<0.05)。鱼油组血浆、血小板、心肌及肝脏中EPA、DHA含量明显高于其它3组(P<0.001)。以上结果提示,鱼油抑制血小板聚集和血栓形成的机理可能是,鱼油中的EPA和DHA等高不饱和脂肪酸纳入细胞膜后竞争抑制花生四烯酸(AA)代谢,减少血小板TXA_2生成和释放,降低血中TXA_2/PGI_2比值,同时增加血小板内cAMP含量,稳定血小板功能,减少5-HT,钙离子等具有促聚活性物质释放。另外,鱼油降低血脂、血浆纤维蛋白原含量及血液粘度,从而改善血液流变性,使血小板本身及其周围环境得以改善,防止血小板聚集和血栓形成。     

1H nuclear magnetic resonance study of olive oils commercially available as Italian products in the United States of America

Multivariate analysis of (1)H NMR data has been used for the characterization of 12 blended olive oils commercially available in the U.S. as Italian products. Chemometric methods such as unsupervised Principal Component Analysis (PCA) allowed good discrimination and gave some affinity indications for the U.S. market olive oils compared to other single cultivars of extra virgin olive oil such as Coratina and Ogliarola from Apulia, one of Italy's leading olive oil producers, Picual (Spain), Kalamata (Greece) and Sfax (Tunisia). The olive oils commercially available as Italian products in the U.S. market clustered into 3 groups. Among them only the first (7 samples) and the second group (2 samples) showed PCA ranges similar to European references. Two oils of the third group (3 samples) were more similar to Tunisian references. In conclusion, our study revealed that most EVOO (extra virgin olive oils) tested were closer to Greek (in particular) and Spanish olive oils than Apulia EVOO. The PCA loadings disclose the components responsible for the discrimination as unsaturated (oleic, linoleic, linolenic) and saturated fatty acids. All are of great importance because of their nutritional value and differential effects on the oxidative stability of oils. It is evident that this approach has the potential to reveal the origin of EVOO, although the results support the need for a larger database, including EVOO from other Italian regions.     

Usefulness of Extra Virgin Olive Oil Minor Polar Compounds in the Management of Chronic Kidney Disease Patients

Chronic kidney disease (CKD) is one of the most common chronic non-communicable degenerative diseases and it represents an important risk factor for cardiovascular morbidity and mortality. The Mediterranean diet, in which extra virgin olive oil (EVOO) is the main source of vegetal fats, represents a nutritional-diet regimen that is useful for the treatment of CKD and its comorbidities. We tested two different EVOOs, characterized by a high (Synergy) and medium (Luxolio) content of minor polar compounds (MPCs), detected by HPLC-DAD-MS analysis, in 40 nephropathic patients, at a dose of 40 mL/day for 9 weeks. We evaluated the effects of these two EVOOs on renal function, body composition, oxidative stress, and inflammatory state, after 9 weeks of EVOOs consumption (T1) and after 2 months of wash-out (T2). We observed an improvement of renal function biomarkers (estimated-glomerular filtration rate, albuminuria, azotemia, uric acid), lipid profile, oxidative stress, inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein) and in body composition at T1. These healthy effects were greater and persisted over time after the wash-out period in Synergy patients. The high MPC EVOO content seems to exert an antioxidant and anti-inflammatory effect in nephropathic patients and these protective actions are maintained over time.