Assessment of toxicity of the untreated and treated olive mill wastewaters and soil irrigated by using microbiotests

Hazard assessments based on two measures of toxicity were conducted for the untreated olive mill wastewaters (U), untreated olive mill wastewaters organic extract (UOE), treated olive mill wastewaters (T), treated olive mill wastewaters organic extract (TOE) and extracts of soils ferti-irrigated with untreated (SU) and with treated olive mill wastewaters (ST). The measures of toxicity were achieved by the determination of the bioluminescence inhibition percent (I(B)%) of Vibrio fischeri and by the growth inhibition (GI) of Bacillus megaterium, Pseudomonas fluorescens and Escherichia coli. A bioluminescence inhibition of V. fischeri of 100%, 100%, 65%, 47%, 46% and 30% were obtained with U, UOE, T, TOE, SU and ST respectively. Indeed, even diluted 24 times, a significant bioluminescence inhibition of 96% was obtained by U. However, only 30% bioluminescence inhibition was obtained by 24 times diluted T. Whereas, 24 times diluted, SU and ST did not show a bioluminescence inhibition (3% and 1%, respectively). The GI of B. megaterium, P. fluorescens and E. coli were, respectively, 93%, 72% and 100% by U; 100%, 80% and 100% by UOE; 70%, 60% and 89% by T; 63%, 54% and 68% by TOE; 39%, 27% and 43% by SU and 23%, 0% and 34% by ST. The incubation of U or T in the soil during four months reduced their toxicity by 54% and 35%, respectively. As it was expected, the most resistant bacterium to OMW toxicity is P. fluorescens then B. megaterium and E. coli. V. fischeri remained the most sensitive strain to the toxicity of this sewage what proves again its utilisation as standard of measure of the toxicity.     

Development and validation of a simple reversed-phase HPLC-UV method for determination of oleuropein in olive leaves

A simple, precise, accurate, and selective method is developed and validated for the determination of oleuropein, which is the main phenolic compound in olive leaves. Separation was achieved on a reversed-phase C₁₈ column (5 μm, 150 × 4.6 mm inner diameter) using a mobile phase consisting of acetonitrile/phosphate buffer pH 3.0 (20:80, v/v), at a flow rate of 1.0 mL/minute and UV detection at 280 nm. This method is validated according to the requirements for new methods, which include accuracy, precision, selectivity, robustness, limit of detection, limit of quantitation, linearity, and range. The current method demonstrates good linearity over the range of 3–1000 ppm of oleuropein, with r² > 0.999. The recovery of oleuropein in olive leaves ranges from 97.7% to 101.1%. The method is selective, in that oleuropein is well separated from other compounds of olive leaves with good resolution. The method is also precise—the relative standard deviation of the peak areas of replicate injections of oleuropein standard solution is <1%. The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing analytical operators has proven that the method is robust and rugged. The low limit of detection and limit of quantitation of oleuropein when using this method enable the detection and quantitation of oleuropein at low concentrations.     

Dietary virgin olive oil protects against lipid peroxidation and improves antioxidant status in the liver of rats chronically exposed to ethanol

Excessive ethanol intake induces severe tissue damage particularly in the liver through the generation of reactive oxygen species. The aim of this study was to determine the effect of a virgin olive oil–rich diet on oxidative stress induced by chronic ethanol exposure in rats. Wistar rats were treated daily with a 35% ethanol solution for 6 weeks and fed with a standard chow or a diet containing 5% virgin olive oil. By administering ethanol to rats, a severe toxicity occurred in their liver, as assessed by the significantly elevated levels of serum transaminases. The hepatic malondialdehyde level, indicator of lipid peroxidation, was also increased in ethanol-treated rats, whereas the hepatic antioxidant enzyme activities, namely, superoxide dismutase, glutathione peroxidase, and catalase were significantly reduced. The activity of glutathione reductase remained unchanged in rats. Fatty acid composition of the liver was also significantly changed with ethanol intake. In contrast, virgin olive oil intake during ethanol treatment in rats resulted in a higher antioxidant activity and inhibited toxicity to the liver, as monitored by the reduction of transaminases levels and hepatic lipid peroxidation. Rats showed a better profile of the antioxidant system with normal glutathione peroxidase activity and ameliorated superoxide dismutase and catalase activities. In conclusion, results of this study indicate that olive oil ingestion by rats protects the liver from ethanol-induced oxidative damage by affecting the cellular redox potential.     

Molecular and metabolic effects of extra-virgin olive oil on the cardiovascular gene signature in rodents

Background and aimsOverweight and obesity are major risk factors for degenerative diseases, including cardiometabolic disorders and cancer. Research on fat and fatty acids’ type is attracting less attention than that on carbohydrates. High adherence to a Mediterranean diet is associated with a better prognosis. One characteristic of the Mediterranean diet is extra-virgin olive oil (EVOO) as the foremost source of dietary fat. EVOO is different from other vegetable oils because it contains peculiar “minor” components, mainly phenolic in nature. Even though olive oil is highly caloric, unrestricted use of olive oil in the PREDIMED trial did not result in weight gain. We sought to study the effects of EVOO in an appropriate mouse model of increased body weight. Furthermore, we explored the biochemical and metabolomic responses to EVOO consumption.Methods and resultsC57BL/6N male mice were weight-matched and fed ad libitum with the following diets, for 16 weeks: 1) saturated fatty acid diet (SFA) or 2) extra-virgin olive oil diet (EVOO), a custom-prepared diet, isocaloric compared to SFA, in which 82% of fat was replaced by high (poly)phenol EVOO. We evaluated glucose homeostasis, serum biochemistry and plasma metabolomics, in addition to cardiac and hepatic gene profile, and mitochondrial respiration rate.ConclusionReplacing saturated fatty acids (e.g. lard) with EVOO translates into moderate yet beneficial cardiometabolic and hepatic effects. Future research will further clarify the mechanisms of action of EVOO (poly)phenols and their role in a balanced diet.     

Efficacy and safety of a combination of red yeast rice and olive extract in hypercholesterolemic patients with and without statin-associated myalgia

Cholesfytol^®, a lipid-lowering dietary supplement with antioxidant and anti-atherosclerotic properties, combines red yeast rice (RYR) and olive extract (5 mg hydroxytyrosol equivalent) and represents an alternative for patients who do not wish or are unable to use chemical statins, including individuals with previous statin-associated muscle symptoms (SAMS). A 2-months observational non-randomized study was performed to evaluate the efficacy, tolerance and safety of Cholesfytol^® (1 tablet/day) in 642 hypercholesterolemic patients (mean age: 59 yrs; total cholesterol (TC) ≥200; LDL-C ≥140 mg/dl). Patients were followed by 126 GPs, and included irrespective of SAMS history and/or diabetes. None of the patients were taking statins or other lipid-modifying therapy at inclusion. At baseline, 26% had fasting glucose >100 ≤125 mg/dL, and 5% >125 mg/dL; 32% (n = 194) had a SAMS history; and 21% had atherogenic dyslipidemia (AD). In the entire cohort, pre-treatment TC; non-HDL-C; LDL-C; and TG were 259; 200; 168; 158 mg/dL, respectively, and decreased significantly on treatment (−17.5% (TC) and −23.3% (LDL-C)). Fasting glucose and HbA_1c decreased between visits. The reduction in lipids was greater in patients with higher values at baseline. For comparable pre-treatment values, patients with SAMS history had reductions in TC, LDL-C, non-HDL-C, and apoB₁₀₀ slightly less than patients without myalgia. AD patients had greater on-treatment decrease in TG. Overall, 13 patients reported minor side-effects, and 4 patients reporting myalgia had antecedent SAMS. In conclusion, a substantial decrease in LDL-C was obtained with a combination of RYR and olive extract in high-risk hypercholesterolemic patients, without inducing new-onset SAMS.     

Addition of fish oil to atherogenic high fat diet inhibited atherogenesis while olive oil did not,in LDL receptor KO mice

Background and aimsMediterranean diet has been associated with decreased cardiovascular morbidity and mortality. Both fish and olive oil are key components of this diet. Therefore, we compared their effects on nonalcoholic fatty liver disease (NAFLD) and atherogenesis in a mouse model, fed a high fat diet.Methods and resultsForty nine, female LDL receptor knockout (LDLR KO) mice were allocated into 3 groups and fed an atherogenic high fat (HF) diet for 9 weeks. The HF group was fed a high fat diet alone. A HF + OO group was fed a HF diet with added olive oil (60 ml/kg feed), and the third group (HF + FO) was fed a HF diet with added fish oil (60 ml/kg feed).Both additions of fish and olive oil, significantly decreased plasma cholesterol elevation compared to HF diet. Nevertheless, only fish oil addition reduced significantly atherosclerotic lesion area by 51% compared to HF group. Liver levels of eicosapentenoic (EPA) and docosahexaenoic (DHA) acids were several folds higher in HF + FO group than in HF and HF + OO groups. Liver levels of oleic acid were higher in HF + OO compared to the other groups. Moreover, Fish oil addition significantly decreased NAFLD scores related to steatosis and inflammation and lowered the expression of the inflammatory genes interleukin 6 (IL6) and monocyte chemoattractant protein 1 (MCP1).ConclusionThese results suggest that fish oil addition on top of an atherogenic, HF diet, is beneficial, while olive oil is not, in its effect on plaque formation and NAFLD in LDLR KO mice.     

Muscle fibre type composition in the lateral muscle of olive flounder Paralichthys olivaceus

In this paper, a combined-method study has been made on the lateral muscle of the teleost olive flounder Paralichthys olivaceus in just-hatched and adult stages. In just-hatched stage, both slow and fast muscle fibres were detected: (1) in situ hybridization analysis indicated that slow and fast myosin heavy chain genes were specifically expressed in the superficial and deep part of the myotomal muscle, respectively; (2) immunohistochemistry analysis showed that fibres in the deep part reacted with anti-fast myosin antibody F310; (3) western blot analysis detected a weak expression of slow myosin and a strong expression of fast myosin. In adult stage, the slow and fast muscle fibres had their own distribution characteristics: (1) hematoxylin/eosin staining showed the histological characteristics of the muscle fibre composition; (2) histochemical observations showed that the deep muscle fibres, and some fibres near the epidermis, contain alkali-stable myofibrillar ATPase activity; (3) immunohistochemistry analysis indicated that all the deep muscle fibres reacted with F310 antibody and some fibres in the superficial layer of muscle also reacted with F310; (4) western blot analysis showed that fast myosin was expressed both in the blended muscles (the mix of superficial and deep muscles) and deep muscles, while slow myosin was mainly expressed in the blended muscles. These findings suggested that both slow and fast muscle fibres existed in the musculature of the olive flounder in just-hatched and adult stages. Notably, the adult fast fibres also exist in the superficial layer of the muscle.     

Aqueous nitrate ion adsorption/desorption by olive solid waste-based carbon activated using ZnCl2

ZnCl₂ activated carbon (ZnCl₂-AC, with specific surface area ~1480 m²/g) effectively adsorbs nitrate from water with uptake capacity (~5.5 mg/g) four-fold that for other commercial activated carbons (CACs). Kinetics show a small activation energy value (~7 kJ/mol) consistent with a diffusion-controlled process. This is further confirmed by intra-particle diffusion study. Negative thermodynamic parameters (ΔH° ?13.859 kJ/mol, ΔS° ?43.8 J/mol K, and ΔG° ?0.808 kJ/mol) indicate spontaneous nitrate adsorption. The high specific surface area rationalizes the high uptake capacity for the ZnCl₂-AC. A Langmuir type adsorption, is observed. ZnCl₂-AC effectively adsorbs the nitrate from water, even at high concentrations, and brings the concentration to allowed maximum values. Despite these advantages, the ZnCl₂-AC exhibits low desorption (~20%) of pre-adsorbed nitrate ions into concentrate solutions. Up to ~40% desorption is observed by grinding the pre-saturated ZnCl₂-AC. Developing other methods to completely recover the adsorbed nitrate and the adsorbent for multiple use is needed.     

Consumption of food fried in olive oil and unhealthy aging in a Mediterranean country

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