Polycyclic aromatic hydrocarbons (PAHs) levels in propolis and propolis-based dietary supplements from the Italian market

Propolis and propolis-based extracts, attained from beekeepers and the local market, were analysed for the presence of 13 polycyclic aromatic hydrocarbons (PAHs), including eight high molecular weight PAHs (PAH8), recently indicated by the European Food Safety Authority (EFSA) as suitable indicators of the presence of carcinogenic and genotoxic PAH in foods. An analytical procedure based on microwave assisted saponification/extraction, high performance liquid chromatography (HPLC) and spectrofluorometric detection, has been developed. About half of the samples analysed presented benzo[a]pyrene (BaP) concentrations exceeding 2 μg/kg, which is proposed as a regulatory limit for dietary supplements. A product-by-product approach (based on maximum recommended dosage) was used to calculate PAH exposure. Even thought the majority of the samples gave low exposure levels when compared to exposure levels from other diet constituents, PAH intakes deriving from a daily consumption of some of the investigated products provided an important contribution to the total dietary intake and lead to margin of exposure (MOE) values which are of concern for human health.     

Milk yield,quality, and coagulation properties of 6 breeds of goats: Environmental and individual variability

Goat milk and cheese production is continuously increasing and milk composition and coagulation properties (MCP) are useful tools to predict cheesemaking aptitude. The present study was planned to investigate the extension of lactodynamographic analysis up to 60 min in goat milk, to measure the farm and individual factors, and to investigate differences among 6 goat breeds. Daily milk yield (dMY) was recorded and milk samples collected from 1,272 goats reared in 35 farms. Goats were of 6 different breeds: Saanen and Camosciata delle Alpi for the Alpine type, and Murciano-Granadina, Maltese, Sarda, and Sarda Primitiva for the Mediterranean type. Milk composition (fat, protein, lactose, pH; somatic cell score; logarithmic bacterial count) and MCP [rennet coagulation time (RCT, min), curd-firming time (k₂₀, min), curd firmness at 30, 45, and 60 min after rennet addition (a₃₀, a₄₅, and a₆₀, mm)] were recorded, and daily fat and protein yield (dFPY g/d) was calculated as the sum of fat and protein concentration multiplied by the dMY. Data were analyzed using different statistical models to measure the effects of farm, parity_, stage of lactation and breed; lastly, the direct and the indirect effect of breed were quantified by comparing the variance of breed from models with or without the inclusion of linear regression of fat, protein, lactose, pH, bacterial, somatic cell counts, and dMY. Orthogonal contrasts were performed to compare least squares means. Almost all traits exhibited high variability, with coefficients of variation between 32 (for RCT) and 63% (for a₃₀). The proportion of variance regarding dMY, dFPY, and milk composition due to the farm was moderate, whereas for MCP it was low, except for a₆₀, at 69%. Parity affected both yield and quality traits of milk, with least squares means of dMY and dFPY showing an increase and RCT and curd firmness traits a decrease from the first to the last parity class. All milk quality traits, excluding fat, were affected by the stage of lactation; RCT and k₂₀ decreased rapidly and a₃₀ was higher from the first to the last part of lactation. Alpine breeds showed the highest dMY and dFPY but Mediterranean the best percentage of protein, fat, and lactose and a shorter k₂₀ and a greater a₃₀. Among the Mediterranean goats, Murciano-Granadina goats had the highest milk yield, fat, and protein contents, whereas Maltese, Sarda, and Sarda Primitiva were characterized by much more favorable technological properties in terms of k₂₀, a₃₀, and a₄₅. In conclusion, as both the farm and individual factors highly influenced milk composition and MCP traits, improvements of these traits should be based both on modifying management and individual goat factors. As expected, several differences were attributable to the breed effect, with the best milk production for the Alpines and milk quality and coagulation for the Mediterranean goats.     

The Presence of Blood–Brain Barrier Modulates the Response to Magnesium Salts in Human Brain Organoids

Magnesium (Mg) is fundamental in the brain, where it regulates metabolism and neurotransmission and protects against neuroinflammation. To obtain insights into the molecular basis of Mg action in the brain, we investigated the effects of Mg in human brain organoids, a revolutionary 3D model to study neurobiology and neuropathology. In particular, brain organoids derived from human induced pluripotent stem cells were cultured in the presence or in the absence of an in vitro-generated blood–brain barrier (BBB), and then exposed to 1 or 5 mM concentrations of inorganic and organic Mg salts (Mg sulphate (MgSO₄); Mg pidolate (MgPid)). We evaluated the modulation of NMDA and GABAergic receptors, and BDNF. Our data suggest that the presence of the BBB is essential for Mg to exert its effects on brain organoids, and that 5 mM of MgPid is more effective than MgSO₄ in increasing the levels of GABA receptors and BDNF, and decreasing those of NMDA receptor. These results might illuminate novel pathways explaining the neuroprotective role of Mg.     

Clinical and Functional Study of a De Novo Variant in the PVP Motif of Kv1.1 Channel Associated with Epilepsy,Developmental Delay and Ataxia

Mutations in the KCNA1 gene, encoding the voltage-gated potassium channel Kv1.1, have been associated with a spectrum of neurological phenotypes, including episodic ataxia type 1 and developmental and epileptic encephalopathy. We have recently identified a de novo variant in KCNA1 in the highly conserved Pro-Val-Pro motif within the pore of the Kv1.1 channel in a girl affected by early onset epilepsy, ataxia and developmental delay. Other mutations causing severe epilepsy are located in Kv1.1 pore domain. The patient was initially treated with a combination of antiepileptic drugs with limited benefit. Finally, seizures and ataxia control were achieved with lacosamide and acetazolamide. The aim of this study was to functionally characterize Kv1.1 mutant channel to provide a genotype–phenotype correlation and discuss therapeutic options for KCNA1-related epilepsy. To this aim, we transfected HEK 293 cells with Kv1.1 or P403A cDNAs and recorded potassium currents through whole-cell patch-clamp. P403A channels showed smaller potassium currents, voltage-dependent activation shifted by +30 mV towards positive potentials and slower kinetics of activation compared with Kv1.1 wild-type. Heteromeric Kv1.1+P403A channels, resembling the condition of the heterozygous patient, confirmed a loss-of-function biophysical phenotype. Overall, the functional characterization of P403A channels correlates with the clinical symptoms of the patient and supports the observation that mutations associated with severe epileptic phenotype cluster in a highly conserved stretch of residues in Kv1.1 pore domain. This study also strengthens the beneficial effect of acetazolamide and sodium channel blockers in KCNA1 channelopathies.     

Cholesterol-Containing Liposomes Decorated With Au Nanoparticles as Minimal Tunable Fusion Machinery

Membrane fusion is essential for the basal functionality of eukaryotic cells. In physiological conditions, fusion events are regulated by a wide range of specialized proteins, operating with finely tuned local lipid composition and ionic environment. Fusogenic proteins, assisted by membrane cholesterol and calcium ions, provide the mechanical energy necessary to achieve vesicle fusion in neuromediator release. Similar cooperative effects must be explored when considering synthetic approaches for controlled membrane fusion. We show that liposomes decorated with amphiphilic Au nanoparticles (AuLips) can act as minimal tunable fusion machinery. AuLips fusion is triggered by divalent ions, while the number of fusion events dramatically changes with, and can be finely tuned by, the liposome cholesterol content. We combine quartz-crystal-microbalance with dissipation monitoring (QCM-D), fluorescence assays, and small-angle X-ray scattering (SAXS) with molecular dynamics (MD) at coarse-grained (CG) resolution, revealing new mechanistic details on the fusogenic activity of amphiphilic Au nanoparticles (AuNPs) and demonstrating the ability of these synthetic nanomaterials to induce fusion regardless of the divalent ion used (Ca²⁺ or Mg²⁺). The results provide a novel contribution to developing new artificial fusogenic agents for next-generation biomedical applications that require tight control of the rate of fusion events (e.g., targeted drug delivery).     

Bio-electrochemical production of hydrogen and electricity from organic waste: preliminary assessment

Clean Technologies and Environmental Policy - This study investigated the performance of a novel integrated bio-electrochemical system for synergistic hydrogen production from a process combining a...     

Leachability and basicity of Na- and K-based geopolymer powders and lattices used as biodiesel catalysts

Geopolymer powders and 3D-printed lattices have shown promising preliminary results as heterogeneous catalysts for the transesterification of vegetable oils to produce biodiesel. However, questions about the basicity of catalytic sites and the leaching characteristics of metals (K, Na) and hydroxyl groups in the reactional mixtures remained. The leaching of alkaline ions in methanol and biodiesel for powder and printed geopolymer formulations based on K, Na, or Na+K activators and treated at 110 to 700°C was investigated, as well as the physiochemical modifications of the materials. The Hammett indicators were used to determine base strength, and both leachable and total basicities were quantified. The amount of Na and K leached into the biodiesel phase was negligible (<1% wt.%). Methanol leaching reached a maximum of 29.3%. The base strength ranged between 11.0 and 18.4. Potassium-based geopolymer lattices presented the highest basicity, followed by sodium and sodium-potassium geopolymer catalysts. The basicity of all formulations decreased gradually as the calcination temperature increased. When compared to the homogeneous catalysts NaOH and KOH, the level of biodiesel contamination with Na and K is 81–93% lower. The findings support the heterogeneous nature of geopolymers as biodiesel catalysts and further validates their use for this application.     

Nanoencapsulation systems to improve solubility and antioxidant efficiency of a grape marc extract into hazelnut paste

Encapsulation of a phenolic grape marc extract to enhance its lipid solubility and antioxidant efficiency for application as a natural preserving agent of hazelnut paste was investigated. Three nanoemulsion based encapsulation systems were tested: an oil/water nanoemulsion; a powder obtained by maltodextrin-assisted spray-drying of the previous and an ethanol/solid–lipid nanoemulsion (the third also applied to resveratrol for comparison). All the samples were mixed with hazelnut paste at different phenolic concentrations (from 1200 to less than 10 ppm of gallic acid equivalents for the original and encapsulated extracts, respectively). An accelerated shelf-life test at 60 °C was carried out until 59 and 98 days (for the original and encapsulated extracts, respectively) with peroxides value monitoring. Paste oxidation followed a first-order kinetics model and was significantly inhibited by extract addition. Encapsulation improved phenolic efficiency against lipid oxidation, by increasing extract dispersability in the paste and preserving the antioxidant activity, with the oil/water nanoemulsion resulting as the best system.