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.     

Genetic variations of CYP2B6 gene were associated with plasma BPDE-Alb adducts and DNA damage levels in coke oven workers

Polycyclic aromatic hydrocarbons (PAHs), the main components of coke oven emissions, can induce activation of cytochrome P450 (CYP) enzymes, which metabolize PAHs and result in DNA damage by forming adducts. This study was designed to know whether genetic variants of CYP genes are associated with plasma benzo[a]pyrene-7,8-diol-9,10-epoxide-albumin (BPDE-Alb) adducts and DNA damage in coke oven workers. In this study, 298 workers were divided into four groups according to the environmental PAHs exposure levels. The concentrations of plasma BPDE-Alb adducts were detected by reverse-phase high-performance liquid chromatography and the DNA damage levels were measured using comet assay. Twelve tag single nucleotide polymorphisms (tagSNPs) of 4 CYP genes were selected and genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In the top group, workers with CYP2B6 rs3760657GA genotype have lower BPDE-Alb adducts and DNA damage levels than those with rs3760657GG genotype (P < 0.05). In the control group, the DNA damage levels of subjects with CYP1A1 rs4646421AA or GA + AA genotypes were lower than those with GG genotype (P < 0.05). However, no such effects were shown for the other tagSNPs. These results suggested that genetic variations of CYP2B6 might be associated with low BPDE-Alb adducts and DNA damage levels in worker with high exposure to PAHs.     

Atherosclerosis regression study in rabbits upon olive pomace polar lipid extract administration

Background and aimsVirgin olive oil polar lipid extract (OOPL) and olive pomace polar lipid extract (PPL) have similar antiatherosclerotic effects in cholesterol-fed rabbits. Our aim was to compare the effect of PPL with that of simvastatin on the progression of atherogenesis.Methods and resultsRabbits were fed an atherogenic diet for 6 weeks in order to develop dyslipidemia and atheromatous lesions. Following documentation of these events in random animals (group A, n = 6), the remaining were fed for 3 weeks with: standard chow alone (group B, n = 6), chow supplemented with PPL (group C, n = 6), and chow supplemented with simvastatin (group D, n = 6). Blood was collected at 0, 6 and 9 weeks, to determine plasma lipid levels, plasma PAF-AH activity, platelet aggregation (PAF-EC₅₀), resistance of plasma to oxidation (RPO) and extent of atheromatous lesions in aortas. The atherogenic diet induced dyslipidemia and increased PAF-AH activity. Dyslipidemia and PAF-activity reduced more effectively in groups C and D. RPO decreased in group B only. PAF-EC₅₀ values decreased in group C only. Atherogenesis progression in group C was prevented to an extent indistinguishable from that in group D. PAF-AH activity was positively correlated, whereas RPO was negatively correlated with the extent of atheromatous lesions.ConclusionPPL, as a dietary supplement, is equipotent to simvastatin in preventing the progression of atherogenesis.     

Olive, soybean and palm oils intake have a similar acute detrimental effect over the endothelial function in healthy young subjects

Background and aimCurrently, more than 30% of the caloric intake in the Colombian population comes from vegetable oil consumption mainly by the ingestion of deep-fried foods. Recently, it has been reported that unsaturated fatty acid rich oils have a beneficial effect on the endothelial function. Nevertheless, it is well know that the deep-frying process alters the chemical composition of vegetable oils and can produce adverse effects in the endothelial function.ObjectiveTo evaluate the acute effect of the ingestion of large amounts of olive, soybean and palm oils, fresh and at two different deep-fry levels, on the glucose and lipid profiles and the endothelial function.Methods and resultsTen healthy young volunteers were included in the study. After performing a baseline evaluation of cardiovascular risk factors and drawing a fasting blood sample, subjects were exposed to a randomly assigned potato soup meal containing 60 mL of one of three different vegetable oils (olive, soybean and palm), either fresh or at one of two different deep-fry levels (10 and 20 fries, respectively). Flow-mediated vasodilation (FMD) was performed in fasting conditions and 3 h after the intake of the oil rich meal. Furthermore, blood samples were taken at these stages for the lipid profiles and plasma glucose determinations. All the meals resulted in a similar acute endothelial impairment (FMD decrease of 32.1%, confidence interval [CI] 95%, 28.0–36.2) and postprandial increase in triglycerides (27.03%, CI 95%, 20.5–33.3), independently of the type of oil ingested (p = 0.44) and regardless of its deep-fry level (p = 0.62). No correlation was found between endothelial impairment and postprandial triglyceride increment (r = −0.22, p = 0.09).ConclusionsNo difference was found in the acute adverse effect of the ingestion of different vegetable oils on the endothelial function. All the vegetable oils, fresh and deep-fried, produced an increase in the triglyceride plasma levels in healthy subjects.     

Stability and efficacy of the 3′-UTR A4G-G5A variant of viral hemorrhagic septicemia virus (VHSV) as a live attenuated immersion VHSV vaccine in olive flounder (Paralichthys olivaceus)

Viral hemorrhagic septicemia virus (VHSV) is the causative agent of viral hemorrhagic septicemia in fish, a disease that affects a number of teleost fish species including olive flounder (Paralichthys olivaceus). In this study, we assessed the safety and efficacy of two recombinant attenuated VHSV strains, termed A4G-G5A and ΔNV, with the purpose to select the most suitable vaccine strain. The virus strains were passaged in two commercially available cell lines, EPC and RTG-2, and the strains were also tested for residual virulence in zebrafish (Danio rerio). The A4G-G5A strain showed an attenuated growth profile in both the EPC and RTG-2 cell lines compared to wild-type (WT) VHSV (JF-09, genotype IVa), whereas the growth profile of ΔNV was comparable to the WT strains in RTG-2 cells in contrast to EPC cells. Moreover, ΔNV had higher residual virulence compared to A4G-G5A and was highly pathogenic to zebrafish. The A4G-G5A strain was chosen as vaccine candidate and tested for efficacy in in vivo fish studies in the target species, olive flounder, using an immersion vaccine scheme. Groups of fish were immunized with 10^2.5, 10^3.5, 10^4.5, and 10^5.5 TCID₅₀/ml of A4G-G5A giving 5–13.3 cumulative percent mortality (CPM) post immunization. Immunization was followed by a challenge experiment using VHSV-WT. The relative percent survival (RPS) in immunized groups ranged from 81.6% to 100%, correlating with vaccination dose. This study demonstrates that while strain A4G-G5A has retained some residual virulence it confers high level of protection in immunized olive flounder.     

Biomechanics of Olive Wire Positioning and Tensioning Characteristics

Abstract Objectives: The effect of the olive wire on the stiffness of external fixation was studied previously, but there is limited data on the effect of the olive wire positioning and tensioning characteristics on the stiffness of external fixation. This study evaluated the influence of olive wire positioning (medially, laterally, posteriorly, and anteriorly) and tensioning characteristics (tensioning one end or both ends) on the stiffness of ring external fixation. Methods: A fiberglass composite tibia fixed into an idealized ring external frame was tested. All mechanical testing was performed with a servo-hydraulic test frame (MTS Bionix 858, Minneapolis, MN, USA). Load–deformation behavior was compared among different wire design, olive wire positioning and tensioning characteristics under central axial compression, medial compression-bending, posterior compression-bending, posteromedial compression-bending and torsion. The differences between tension values on opposite ends of the wire during different modalities of olive wire tensioning were also investigated. Results: Olive wires tensioned on both ends provided significantly greater bending stiffness compared to smooth wires and olive wires tensioned only on the end opposite to the olive (p < 0.05). There was a significant difference between the tension values on opposite ends of the olive wire during tensioning (p < 0.05). Conclusions: Tensioning both ends of the olive wires and positioning the olives on the side of bending significantly increases the bending stiffness of ring external fixation. This work provides a rationale for clinical decision-making about the use of tensioned olive wires as opposed to smooth wires in ring external fixation.     

Minor polar compounds extra-virgin olive oil extract (MPC-OOE) inhibits NF-κB translocation in human monocyte/macrophages

Epidemiological studies demonstrate that the Mediterranean diet, in which olive oil is the major source of fat, reduces the risk of coronary heart disease and cancer. It has been proposed that the beneficial effects of olive oil not only depend on oleic acid, but are also associated with minor polar compounds (MPC). A positive correlation between inflammation and cardiovascular diseases has long been described, monocyte/macrophages and NF-kappaB playing a pivotal role. The aim of this work was to investigate the effects of an extra-virgin olive oil extract (MPC-OOE), particularly rich in MPC and prepared by some of us, on NF-kappaB translocation in monocytes and monocyte-derived macrophages (MDM) isolated from healthy volunteers. In a concentration-dependent manner, MPC-OOE inhibited p50 and p65 NF-kappaB translocation in both un-stimulated and phorbol-myristate acetate (PMA)-challenged cells, being particularly effective on the p50 subunit. Interestingly, this effect occurred at concentrations found in human plasma after nutritional ingestion of virgin olive oil and was quantitatively similar to the effect exerted by ciglitazone, a PPAR-gamma ligand. However, MPC-OOE did not affect PPAR-gamma expression in monocytes and MDM. These data provide further evidence of the beneficial effects of extra-virgin olive oil by indicating its ability to inhibit NF-kappaB activation in human monocyte/macrophages.     

Osteoarthritis and its management - Epidemiology,nutritional aspects and environmental factors

Osteoarthritis (OA) is the most prevalent chronic rheumatic diseases worldwide, with a strong impact on individual and population health. OA is a clinically heterogeneous disease presenting with different clinical phenotypes recognising systemic and local risk factors. The pathogenesis is multifactorial including constitutive features of the joint, non-modifiable and modifiable risk factors. Epidemiological studies highlight the link between metabolic syndrome and OA and the effect of interplay between immunological and metabolic processes is getting increasing emphasis because of to the discovery that metabolic syndrome is implicated in OA pathogenesis and progression. In addition, recent findings suggest a potential role of dietary factors in susceptibility and progression of OA. In this review, we summarise the most robust evidence on epidemiology and classical risk factors OA, also exploring the most recent evidence on metabolic changes and Mediterranean diet for OA as a possible target to impact on the natural history of the disease.