Laura Pucci

Lack of association between endothelial nitric oxide synthase gene polymorphisms, microalbuminuria and endothelial dysfunction in hypertensive men

Background The Glu298Asp, T786C and 4a/4b genetic polymorphisms within the endothelial nitric oxide synthase (e-NOS) gene may predispose to hypertension, ischaemic heart disease and renal damage, possibly by reducing the generation of nitric oxide (NO), a fundamental substance in renal and cardiovascular biology. That same mechanism may contribute to raise albuminuria, a correlate of endothelial dysfunction and a marker of early kidney damage and poor cardiovascular prognosis in patients with hypertension. To assess that hypothesis, we evaluated the association of albuminuria with eNOS genotypes and their interacting potential with the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism. We also tested their impact on systemic NO availability, as reflected by endothelial-mediated forearm vasodilatation. Methods Albuminuria (three overnight collections), blood pressure, body mass index, renal function, glucose, lipids and prevalence of the metabolic syndrome were measured in 235 genetically unrelated, never-treated, uncomplicated white men with essential hypertension. Endothelial function was assessed in a patient subgroup (n = 94) by measuring plethysmographic forearm blood flow vasodilatation in response to intra-arterial acetylcholine with sodium nitroprusside as a control. Polymerase chain reaction or a 5′ nuclease assay were used to characterize the eNOS and ACE I/D variants. Results Albuminuria or microalbuminuria (albuminuria ≥ 15 μg/min) showed no association with eNOS polymorphisms either per se or after accounting for the co-existing ACE I/D genetic configuration. Forearm responses to acetylcholine did not differ by eNOS polymorphisms. Cardiovascular, renal, metabolic parameters were homogeneously distributed across different genetic backgrounds. Conclusion eNOS polymorphisms apparently play no role in promoting hypertensive renal damage, and do not influence endothelial-mediated vasodilatation in never-treated men with essential hypertension.

Grain and Bean Lysates Improve Function of Endothelial Progenitor Cells from Human Peripheral Blood: Involvement of the Endogenous Antioxidant Defenses

Increased oxidative stress contributes to the functional impairment of endothelial progenitor cells (EPCs), the pivotal players in the servicing of the endothelial cell lining. Several evidences suggest that decreasing oxidative stress by natural compounds with antioxidant properties may improve EPCs bioactivity. Here, we investigated the effects of Lisosan G (LG), a Triticum Sativum grain powder, and Lady Joy (LJ), a bean lysate, on function of EPCs exposed to oxidative stress. Peripheral blood mononuclear cells were isolated and plated on fibronectin-coated culture dishes; adherent cells, identified as early EPCs, were pre-treated with different concentrations of LG and LJ and incubated with hydrogen peroxide (H2O2). Viability, senescence, adhesion, ROS production and antioxidant enzymes gene expression were evaluated. Lysate-mediated Nrf-2 (nuclear factor (erythroid-derived 2)-like 2)/ARE (antioxidant response element) activation, a modulator of oxidative stress, was assessed by immunocytochemistry. Lady Joy 0.35–0.7 mg/ml increases EPCs viability; pre-treatment with either LG 0.7 mg/ml and LJ 0.35–0.7 mg/ml protect EPCs viability against H2O2-induced injury. LG 0.7 and LJ 0.35–0.7 mg/ml improve EPCs adhesion; pre-treatment with either LG 0.35 and 0.7 mg/ml or LJ 0.35, 0.7 and 1.4 mg/ml preserve adhesiveness of EPCs exposed to H2O2. Senescence is attenuated in EPCs incubated with lysates 0.35 mg/ml. After exposure to H2O2, LG pre-treated cells show a lower senescence than untreated EPCs. Lysates significantly decrease H2O2-induced ROS generation. Both lysates increase glutathione peroxidase-1 and superoxide dismutase-2 (SOD-2) expression; upon H2O2 exposure, pre-treatment with LJ allows higher SOD-2 expression. Heme oxigenase-1 increases in EPCs pre-treated with LG even upon H2O2 exposure. Finally, incubation with LG 0.7 mg/ml results in Nrf-2 translocation into the nucleus both at baseline and after the oxidative challenge. Our data suggest a protective effect of lysates on EPCs exposed to oxidative stress through the involvement of antioxidant systems. Lisosan G seems to activate the Nrf-2/ARE pathways.

Alpha-adducin and angiotensin-converting enzyme polymorphisms in hypertension: evidence for a joint influence on albuminuria.

Background A single-nucleotide polymorphism (Gly460Trp) within the α-adducin gene (ADD1) may influence several renal phenotypes, including salt sensitivity, susceptibility to renal failure, the renal haemodynamics and confer a worse cardiovascular risks profile. However, its relationship with microalbuminuria, a marker of early renal and cardiovascular damage and an independent predictor of morbid events in hypertension, is unknown. For this reason, we related the ADD1 genetic polymorphism to urine albumin levels and other clinical variables in essential hypertensive men. The angiotensin-converting enzyme (ACE) insertion/deletion (ID) polymorphism was also evaluated because of its interactive potential with the ADD1 genotype. Methods Albuminuria (three overnight collections), echocardiographic left ventricular mass index, blood pressure, body mass index, renal function, glucose and lipids were measured in 238 genetically unrelated, never treated, uncomplicated Caucasian essential hypertensive men. Polymerase chain reaction or a 5′ nuclease assay were used to characterize the ACE ID and ADD1 Gly460Trp variants, respectively. Results Microalbuminuria (albuminuria ≥ 15 μg/min) was more frequent in patients with the ACE DD variant, but only in those with a ADD1 Gly460Gly background. In contrast, urine albumin did not differ by ACE ID genotype in the presence of mutated ADD1 Trp alleles. ADD1 polymorphisms per se were not associated with albuminuria. Cardiovascular, renal, metabolic parameters were homogeneously distributed among different genetic backgrounds. Conclusions ACE DD and ADD1 Gly460Gly polymorphisms may jointly influence albuminuria in hypertensive men, 460Gly homozygosis facilitating or, possibly, the 460Trp allele mitigating the noxious renal impact of the ACE DD genotype. The data highlight further the complex pathophysiological implications of microalbuminuria in hypertension.

Palynological origin, chemical composition, lipid peroxidation and fatty acid profile of organic Tuscanian bee-pollen

The aim of this work is to characterize fresh bee-pollen in order to define the main nutritional properties of this apiary product for future legislation. Organic bee-pollen (n = 5) harvested from Lucca (Tuscany, Italy) was studied for palynological analysis, nutritional content (dry matter, crude protein, lipid, ash and carbohydrate contents), thiobarbituric acid reactive substances (TBARS) content and fatty acids (FA) profile. The chemical composition analyses showed an average of 849 g/kg for dry matter, 253 g/kg for proteins, 12.9 g/kg for lipids, 24.7 g/kg for ash, and 561 g/kg for carbohydrates. The average value of TBARS content was 0.96 mg malondialdehyde/kg. Concerning FA composition, results showed differences among organic Tuscanian bee-pollen species. All the investigated pollen species had linoleic acid with a mean value of 55.4 g/kg of total FAs and, α-linolenic acid, with a mean value of 147 g/kg of total FAs. An average n-6/n-3 polyunsaturated fatty acid (n-6/n-3 PUFA) ratio of 1.70 was found. Considering that the n-6/n-3 PUFA ratio and linoleic acid/α-linolenic acid ratio are considered important for the prevention of human diseases, the Tuscanian organic bee-pollen may be of nutraceutical relevance.

A fermented bean flour extract downregulates LOX-1, CHOP and ICAM-1 in HMEC-1 stimulated by ox-LDL

This study focused on an extract from fermented flour from the Lady Joy variety of the common bean Phaseolus vulgaris. The extract, Lady Joy lysate (Lys LJ), is enriched in antioxidant compounds during the fermentation. We assessed it for its protective effect on endothelial cells treated with oxidized-LDL (ox-LDL). The oxidative stress was determined by measuring the contents of thiobarbituric acid-reactive substances and reactive oxygen metabolites. ICAM-1, ET-1 and IL-6 concentrations were assessed using ELISA. LOX-1 and CHOP expression were analyzed using both quantitative RT-PCR and ELISA or western blotting. Ox-LDL treatment induced significant oxidative stress, which was strongly reduced by pre-treatment with the extract. The ox-LDL exposure significantly enhanced ICAM-1, IL-6 and ET-1 levels over basal levels. Lys LJ pre-treatment exerted an inhibitory effect on ox-LDL-induced endothelial activation with ICAM-1 levels comparable to those for the untreated cells. IL-6 and ET-1 production, although reduced, was still significantly higher than for the control. Both LOX-1 and CHOP expression were upregulated after ox-LDL exposure, but this effect was significantly decreased after Lys LJ pre-treatment. Lys LJ alone did not alter the ICAM-1, IL-6 and ET-1 concentrations or CHOP expression, but it did significantly lower the LOX-1 protein level. Our data suggest that Lys LJ is an effective antioxidant that is able to inhibit the oxidation process, but that it is only marginally active against inflammation and ET-1 production in HMEC-1 exposed to ox-LDL.

Effects of low sulfur dioxide concentrations on bioactive compounds and antioxidant properties of Aglianico red wine

This study analyzed the effect of low sulfur dioxide concentrations on the chromatic properties, phytochemical composition and antioxidant activity of Aglianico red wines with respect to wines produced from conventional winemaking. We determined the phytochemical composition by spectrophotometric methods and HPLC-DAD analysis and the in vitro antioxidant activity of different wine samples by the ORAC assay. The main important classes of fluorophore molecules in red wine were identified by Front-Face fluorescence spectroscopy, and the emission intensity trend was investigated at various sulfur dioxide concentrations. Lastly, we tested the effects of both conventional and low sulfite wines on ex vivo human erythrocytes under oxidative stimulus by the cellular antioxidant activity (CAA) assay and the hemolysis test. The addition of sulfur dioxide, which has well-known side effects, increased the content of certain bioactive components but did not raise the erythrocyte antioxidant capacity.