Melatonin in Medicinal and Food Plants : Occurrence, Bioavailability, and Health Potential for Humans

Melatonin is a widespread molecule among living organisms involved in multiple biological, hormonal, and physiological processes at cellular, tissue, and organic levels. It is well-known for its ability to cross the blood-brain barrier, and renowned antioxidant effects, acting as a free radical scavenger, up-regulating antioxidant enzymes, reducing mitochondrial electron leakage, and interfering with proinflammatory signaling pathways. Detected in various medicinal and food plants, its concentration is widely variable. Plant generative organs (e.g., flowers, fruits), and especially seeds, have been proposed as having the highest melatonin concentrations, markedly higher than those found in vertebrate tissues. In addition, seeds are also rich in other substances (lipids, sugars, and proteins), constituting the energetic reserve for a potentially growing seedling and beneficial for the human diet. Thus, given that dietary melatonin is absorbed in the gastrointestinal tract and transported into the bloodstream, the ingestion of medicinal and plant foods by mammals as a source of melatonin may be conceived as a key step in serum melatonin modulation and, consequently, health promotion

Проблеми відтворення трудових ресурсів сільських територій

Павленко, Н. В. Проблеми відтворення трудових ресурсів сільських територій / Наталія Вікторівна Павленко, Світлана Юріївна Кобилінська // Сучасні проблеми правового, економічного та соціального розвитку держави : тези доп. ХІ Міжнар. наук.-практ. конф. (м. Вінниця, 9 груд. 2022 р.) / МВС України, Харків. нац. ун-т внутр. справ, Наук. парк «Наука та безпека». – Вінниця, 2022. – С. 162-163.Проведено аналіз стану відтворення трудових ресурсів у сільському господарстві, виділено декілька проблем, що виникли у цій сфері. Зазначено заходи, які сприятимуть відновленню кількості та якості робочої сили, що зайнята у сільськогосподарському виробництві, та його подальшому інтенсивному розвитку.An analysis of the state of reproduction of labor resources in agriculture was carried out, several problems that arose in this area were highlighted. Measures that will contribute to the restoration of the quantity and quality of the labor force employed in agricultural production and its further intensive development are indicated.Проведен анализ состояния воспроизводства трудовых ресурсов в сельском хозяйстве, выделено несколько проблем, возникших в этой сфере. Указаны меры, способствующие восстановлению количества и качества рабочей силы, занятой в сельскохозяйственном производстве, и их дальнейшему интенсивному развитию

Biological and analytical studies of peritoneal dialysis solutions

The purpose of our work was to conduct biological and analytical studies of the peritoneal dialysis (PD) solutions containing glucose and sodium lactate and establish correlations between cell viability of the Vero cell line and values of analytical indexes of the tested solutions. The results of this study confirm the cytotoxicity of the PD solutions even compared with the isotonic solution of sodium chloride, which may be due to the low pH of the solutions, presence of glucose degradation products (GDPs) and high osmolarity of the solutions, and unphysiological concentrations of glucose and sodium lactate. However, it is not yet known what factors or their combination and to what extent cause the cytotoxicity of PD solutions. In the neutral red (NR) test the weak, almost middle (r = -0.496 and 0.498, respectively) and unexpected correlations were found between reduced viability of monkey kidney cells and increased pH of the PD solutions and between increased cell viability and increased absorbance at 228 nm of the tested PD solutions. These two correlations can be explained by a strong correlation (r = -0.948) between a decrease in pH and an increase in the solution absorbance at 228 nm. The opposite effect was observed in the MTT test. The weak, but expected correlations (r = 0.32 and -0.202, respectively) were found between increased cell viability and increased pH in the PD solutions and between decreased cell viability and increased absorbance at 228 nm of the tested PD solutions. The middle and weak correlations (r = 0.56 and 0.29, respectively) were detected between increased cell viability and increased lactate concentration in the NR test and MTT test. The data of these correlations can be partially explained by the fact that a correlation with a coefficient r = -0.34 was found between decreased pH in the solutions and increased lactate concentration. The very weak correlations (0.138 and 0.196, respectively) were found between increased cell viability and increased glucose concentration in the NR test and MTT test. These experimental data indicate that pH is the dominating factor, which determines almost all of the established correlations. However, the character of the correlations is quite different: the higher the pH, the greater was the cell viability in the MTT test, and conversely, the higher the pH, the lower was the cell viability in the NR test. Secondly, the unexpected correlation coefficient was determined as -0.473 between decreased cell viability in the MTT test and increased cell viability in the NR test. Moreover, this phenomenon indicates that the mitochondrial enzyme succinate dehydrogenase is more vulnerable to the action of PD solutions than membrane permeability. Finally, we conclude that the NR test is not suitable for comparative studies of PD solutions which differ in pH, as it is pH dependent and does not enable the comparison of plausible cell viability

Optimization of QuEChERS procedure by hydrophobic magnetic nanocomposites for residual OCPs determination coupled with GC-MS

Resumen del póster presentado a la XX Conference EuroAnalysis, celebrada en Estambul (Turquía) del 1 al 5 de septiembre de 2019.Food safety and environmental protection issues have attracted significant international attention in the recent years. The detection of organochlorine pesticides (OCPs) in food products is of key importance for the health of the consumers. Pesticides are found in food at very low concentrations, the separation and pre-concentration of the target analytes has become one of the most critical steps in the sample preparation technology. The QuEChERS is a type of sample preparation method for screening of pesticides in completely food matrixes. This procedure involves initial extraction with acetonitrile followed by a solid phase extraction with amine-loaded adsorbents in combination with hydrophobic C18 and graphitized carbon black for cleaning-up. In this work the application of magnetite nanoparticles modified with hydrophobic non-ionic surfactant Triton X-100 motives as an excellent clean-up agent is proposed. Hydrophobic groups grafted to the surface of magnetite nanoparticles can effectively remove non-polar components from the food matrix (fat, pigment, etc.) and then the particles can easily be separated from the extract by external magnetic field avoiding additional steps of centrifugation or filtration. The sample preparation method based on QuEChERS implying the use of new magnetic nanocomposite has been applied for the monitoring of various OCPs in food products. Under the found optimal conditions such parameters as sensitivity, precision, recoveries have been evaluated for the target analytes by GC-MS method. The results have shown a good linearity (R2≥ 0.9916), satisfactory average recoveries reaching the values between 89 and 110%, RSD of 2-15 %, except those for the hexane extraction of strawberry, radish and watermelon samples. The OCPs have been detected in strawberry (α- HCH; lindane) and radish (α, β-HCH isomers) samples. The magnetic nanocomposites have provided the lower level of co-extracted interferences (including pigments) in the samples and have displayed a better clean-up performance than C18 or carbon adsorbents. Thus, the developed method demonstrates the improved purification and simultaneous recovery of various OCPs

Efficient adsorption of pharmaceutical drugs from aqueous solution using a mesoporous activated carbon

The removal of widely used pharmaceuticals by new granular mesoporous activated carbon materials prepared via a simple one-step pyrolysis process was studied. The series of mesoporous carbons (MC) were derived from sucrose/polystyrene using two mesoporous matrices: MCM-48 and SBA-15 sieves. Two different activation schemes were used to obtained samples: steam-pyrolysis at 900 °C, and chemical modification (with HNO3, H2O2 and their mixture) at 200 °C. The studied conditions of chemical oxidation led to significant structural alterations. Compared to the activated carbon treated by steam at 900 °C, the treatment via chemical oxidation increased the total volume of pores from 1.09 to 2.73 cm3 g−1. The total adsorption capacity towards tetracycline was found to be proportional to the mesoporous volume and the amount of surface O-containing groups. From the experimental adsorption isotherms, the maximum adsorption capacity was calculated 909.2 mg g−1 for tetracycline at pH 7. The kinetics of adsorption fits the pseudo-second order model perfectly. The adsorption data treated by both Langmuir and Freundlich models indicates that the adsorption was monomolecular. This research provides insight into the adsorption behavior of antibiotics on non-activated and activated mesoporous carbonous materials and facilitates their application to removal of pharmaceuticals from contaminated aqueous solutions. The potential adsorption mechanism of mesoporous carbons for the adsorption of antibiotics was proposed. The granular mesoporous carbon after oxidation by mixture of HNO3 and H2O2 with ration 1:1 exhibited much higher adsorptive activity and still showed relatively high adsorption stability even after five cycles, which were potentially suitable for easy separation and high efficiency.This study was supported by grants from EU FP-7-PEOPLE-2009-IRSES (№ 247603). The University of Oviedo is grateful for financial support from Spain’s Ministry for the Economy and Business - MINECO (MAT2016-78155-C2-1-R).Peer reviewe

Magnetite nanoparticles with aminomethylenephosphonic groups: synthesis, characterization and uptake of europium(III) ions from aqueous media

Two adsorbents with covalently bound aminomethylenephosphonic acid functions (and referred to as MNPs/AMPA and MNPs/SiO2-AMPA) were synthesized from two types of amino-functionalized magnetic nanoparticles (MNPs) via Moedritzer-Irani reaction. The sorbents with anchored dopamine ligand (MNPs/dopa) or aminopropyl groups (MNPs/SiO2-NH2), and the MNPs/AMPA were characterized by X-ray diffraction, FTIR, transmission electron microscopy and vibrating sample magnetometry. Surface modification does not adversely impact the physical properties of the starting magnetite. Compared to the size of the unmodified Fe3O4 (magnetite) nanoparticles (7–12 nm), the average size of functionalized nanoparticles is increased to 10–16 nm. Similarly, the magnetic saturation decreased from 67.5 emu g-1 to 42.0 emu g−1, and the surface area is increased up to 205 m2 g−1 for MNPs/SiO2-AMPA. The kinetics of the adsorption of Eu(III) on the sorbent is ultra-fast, and equilibria are attained within 5–10 min at room temperature. The adsorption kinetics can be described by a pseudo-second-order model. Adsorption and desorption conditions were tested with respect to the removal of Eu(III) ions from water solution. The adsorption capacities for Eu(III) at pH 7.0 are 77 mg g−1 and 69 mg g−1 for MNPs/AMPA and MNPs/SiO2-AMPA nanoparticles, respectively. Eu(III) was quantified by ICP-MS. The limit of detection (LOD) for Eu(III) is 0.05 ng L−1 (based on the 3σ criterion), with an enrichment factor of 150. The selectivity over ions such as Tb(III), Fe(III), Zn(II), Cu(II), and Ca(II) ions was studied. Under optimal condition the distribution coefficient for Eu(III) relative to these ions is near 105 mL g−1. The sorbents can be easily retrieved from even large volumes of aqueous solutions by magnetic separations. The method was tested for spiked water samples (with recoveries from 96.6–102.5%) and for rock minerals.Financial support was provided by Ministry of Economy and Competitiveness (MINECO, Spain) MAT2016-78155-C2-1-R and EU (FP-7-PEOPLE-2009-IRSES grant No. 247603)