Search

Background Selenium is an essential element; however, at higher doses, it can be toxic. Therefore, alternative nanotechnological solutions are required to overcome toxicological issues, rather than conventional alternatives. Nanoparticles show new and promising properties that may be able to suppress toxicity while maintaining the positive effects of selenium on an organism. The aim of the experiment was to determine the influence of sodium selenite and selenium nanoparticles (SeNPs) on the antioxidant status of rats. Methods The males of the outbreed rat strain Wistar albino were selected as a model organism. Animals were fed different forms of selenium. The control group was given a mixture without selenium addition, whereas other groups were fed a mixture containing sodium selenite, Se-49, and Se-100 SeNPs respectively. The duration of the trial was 30 days. Results Analysis of blood and liver was performed where the concentration of reduced (GSH) and oxidised (GSSG) glutathione, and total selenium content were measured. In the liver, a significant reduction in GSSG was found for all experiment groups. Blood samples showed a significant reduction in GSH and an increase in GSSG. Discussion These results show that SeNPs may be an alternative to dietary selenium for animal organisms.

Abstract Graphene oxide (GO) synthesised by modified Tour’s method was decorated with copper and zinc nanoparticles (NPs) and simultaneously reduced by sodium borohydride to obtain a nanocomposite of reduced GO with copper and zinc NPs (rGO–Cu–Zn). The nanocomposite rGO–Cu–Zn was characterised by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The rGO–Cu–Zn was tested against Xanthomonas euvesicatoria (X. euvesicatoria), which attacks tomatoes and causes bacterial spots (BSs), and compared with the commercial product Champion 50 WG. Total bacterial growth inhibition was observed for the 1% rGO–Cu–Zn, whereas Champion 50 WG at the same concentration inhibited but did not eradicate all the bacterial colonies. To evaluate the negative effect of the rGO–Cu–Zn on the molecular level, the expression of the genes associated with the action of abiotic and biotic stress factors was analysed. Gene expression in the plants treated with 10% rGO–Cu–Zn did not exhibit a noticeable increase. Graphical Abstract

Abstract Xanthomonas euvesicatoria (Xe) is of the genera Xanthomonas, which causes a bacterial spot disease that affects tomato and pepper plants, resulting in significant economic losses. Commonly used bactericides lead to pathogen resistance, environmental contamination and a current risk to human health. Herein, a nanocomposite consisting of Cu and Ag loaded onto reduced graphene oxide (rGO) was synthesized, characterized and tested. After confirmation of the antibacterial properties in vitro, nanocomposites at concentrations of 50 and 500 µg mL−1 were applied to protect tomato and pepper plants under controlled greenhouse conditions. The tomato and pepper plants indicated significantly lower disease severity when treated with the nanocomposite (15.6 and 16.7%, respectively) than when treated with the commercial copper-based bactericide Kocide® 2000. The nanocomposite was demonstrated as a high-efficiency biocide and has the potential for crop disease management with no phytotoxic effect. Graphical Abstract

Phytomanagement is proposed as a cost-effective and environmentally-friendly suggestion for sustainable use of large metal-contaminated areas. In the current work, the energy crop miscanthus (Miscanthus × giganteus) was grown in ex situ conditions on agricultural soils presenting a Cd, Pb and Zn contamination gradient. After 93 days of culture, shoot and root growth parameters were measured. Soils and plants were sampled as well to study the TE accumulation in miscanthus and the effects of this plant on TE mobility in soils. Results demonstrated that miscanthus growth depended more on the soils silt content rather than TE-contamination level. Moreover, soil organic carbon at T93 increased in the soils after miscanthus cultivation by 25.5–45.3%, whereas CaCl2-extractible TEs decreased due to complex rhizosphere processes driving plant mineral uptake, and organic carbon inputs into the rhizosphere. In the contaminated soils, miscanthus accumulated Cd, Pb and Zn mainly in roots (BCF in roots: Cd '' Zn > Pb), while strongly reducing the transfer of these elements from soil to all organs and from roots to rhizomes, stems and leaves (average TFs: 0.01–0.06, 0.11–1.15 and 0.09–0.79 corresponding to Cd, Pb and Zn respectively). Therefore, miscanthus could be considered a TE-excluder, hence a potential candidate crop for coupling phytostabilization and biomass production on the studied Metaleurop TE-contaminated soils.

Toxic metals (cadmium, lead, and mercury) in the tissues of common carp fished from three reservoirs (Pilská, Domaninský, and Matějovský) in the Bohemian-Moravian Highlands were measured in the period from April 2013 to September 2014 and the risk of consuming the fish from these localities was evaluated. During this project 25 fish specimens from each locality were analysed. The concentration of metals in muscle tissue and liver was determined by atomic absorption spectrometry. A variation in the content of heavy metals in fish samples and fish tissues was demonstrated and discussed. Higher concentrations of cadmium in the fish tissue were found in 50 samples of carp liver. Because the fish liver is not commonly consumed, common carp from the Moravian-Moravian Highlands does not pose any health risk for consumers. Concentrations of the other monitored toxic metals in fish tissue were low and were complying with the maximum residue limit in all cases.

Two-dimensional materials have recently gained significant awareness. A representative of such materials, black phosphorous (BP), earned attention based on its comprehensive application potential. The presented study focuses on the mode of cellular response underlying the BP interaction with Chlamydomonas reinhardtii as an algal model organism. We observed noticeable ROS formation and changes in outer cellular topology after 72 h of incubation at 5 mg/L BP. Transcriptome profiling was employed to examine C. reinhardtii response after exposure to 25 mg/L BP for a deeper understanding of the associated processes. The RNA sequencing has revealed a comprehensive response with abundant transcript downregulation. The mode of action was attributed to cell wall disruption, ROS elevation, and chloroplast disturbance. Besides many other dysregulated genes, the cell response involved the downregulation of GH9 and gametolysin within a cell wall, pointing to a shift to discrete manipulation with resources. The response also included altered expression of the PRDA1 gene associated with redox governance in chloroplasts implying ROS disharmony. Altered expression of the Cre-miR906–3p, Cre-miR910, and Cre-miR914 pointed to those as potential markers in stress response studies.

Abstract Graphene‐based 2D nanomaterials exhibit unique physicochemical, electric, and optical properties that facilitate applications in a wide range of fields including material science, electronics, and biotechnology. Recent studies have shown that graphene oxide (GO) and reduced graphene oxide (rGO) exhibit antimicrobial effects on bacteria and viruses. While the bactericidal activity of graphene‐based nanomaterials is related to mechanical and oxidative damage to bacterial membranes, their antiviral activity has been less explored. Currently available experimental data are limited and suggest mechanical disruption of viral particles prior to infection. In this study, the antiviral properties of reduced GO‐based nanocomposites decorated with Ag nanoparticles (rGO‐Ag) are evidenced against human immunodeficiency virus‐1 pseudovirus used as an enveloped virus model. By combining biochemical and original single virus imaging approaches, it is shown that rGO‐Ag induces peroxidation of pseudoviral lipid membrane and that consequent alteration of membrane properties leads to a reduction in cell entry. In addition, rGO‐Ag is found to be efficiently internalized in the host cell leading to the elevated expression of pro‐inflammatory cytokines. Altogether, the presented results shed new light on the mechanisms of rGO‐Ag antiviral properties and confirm the high potential of graphene derivatives as an antimicrobial material for biomedical applications.

Abstract The intensive use of insecticides in global agricultural production has attracted much attention due to its many adverse effects on human health and the environment. In recent years, the utilization of nanotechnology has emerged as a tool to overcome these adverse effects. The aim of this work was to test different microparticles (zinc oxide (ZnO MPs) and silicon dioxide microparticles (SiO2 MPs)), and silver nanoparticles (Ag NPs) and to study their toxicity on a model organism, Tenebrio molitor. A comprehensive comparative study, which included more than a thousand mealworms divided into nine separate groups, was conducted. In addition to pure nano/microparticle solutions, the effect of particles mixed with the microalgae extract Chlamydomonas reinhardtii was also observed. Pure Ag NPs and SiO2 MPs resulted in larval mortality of more than 70% compared to that of pure ZnO MPs, in which the mortality rate was approximately 33%. A mixture of the algal extract with zinc oxide microparticles resulted in mortality that was double compared to that observed with pure ZnO MPs. In parallel, atomic absorption spectrometry (AAS) was used to determine the difference in the concentration of trace elements in the bodies of dead and live larvae.

Peas are prospectively beneficial legumes in the human diet, and especially in a vegan and vegetarian diet, due to their high content of proteins and starch. Their frequent lack of appeal in human nutrition can be caused by their bloating effect and the content of some antinutritional compounds inhibiting the absorption of important nutrients. This study brings a comprehensive comparison of the nutrient content of pea flour after cooking and lactic fermentation before and after digestion in vitro. As a control sample, raw pea flour was used (sample 1). Raw pea flour was cooked for 10 min (sample 2) and 120 min (sample 3) at 100°C or it was fermented by Lactobacillus plantarum (sample 4) and cooked for 10 min at 100°C (sample 5). The samples were analyzed for protein and amino acids content, maltose, glucose, raffinose, total polyphenols, phytic acid, phytase, and mineral composition (P, Mg, Mn, Fe, Cu, Zn) before and after in vitro digestion. The results showed a significant (p < 0.05) increase in the protein digestibility of samples 3, 4 and 5. In the fermented samples were observed a higher concentration of Cys, Met, and Gln when compared to non-fermented samples. The fermentation of pea flour resulted in a significant (p < 0.05) decrease in glucose, maltose, and raffinose content. Cooking of pea flour for 10 and 120 min, but not fermenting, significantly (p < 0.05) decreased the polyphenols content. Cooking and fermentation together did not affect phytic acid concentration and phytase activity. Mg, Mn, Fe, Cu and, Zn concentration in pea flour was significantly (p < 0.05) decreased by cooking. On the other hand, fermentation significantly (p

Mycotoxin management in agriculture is an essential challenge for maintaining the health of both animals and humans. Choosing the right adsorbent is still a question for many breeders and an important criterion for feed manufacturers. New adsorbents are still being sought. Graphene oxide is a promising material in the field of nanotechnology, which excels in its adsorption properties. Presented in vitro study investigates graphene oxide for the binding of mycotoxins from crushed wheat. The results show that graphene oxide has an adsorption capacity for aflatoxin 0.045 mg/g, zearalenone 0.53 mg/g and deoxynivalenol 1.69 mg/g at 37° C. In vitro simulation of crushed wheat digestion showed rapid adsorption during the gastric phase. Of the minerals, Mg, Cu and Zn were the most adsorbed. The applied dose of graphene oxide of 10 mg/g caused only a slight inhibition of the digestive enzymes α-amylase and trypsin compared to pepsin and gastric lipase. In vitro results indicated the suitability of graphene oxide in the adsorption of the aflatoxin, zearalenone and deoxynivalenol.

Selenium nanoparticles (SeNPs) are fast becoming a key instrument in several applications such as medicine or nutrition. Questions have been raised about the safety of their use. Male rats were fed for 28 days on a monodiet containing 0.5, 1.5, 3.0 and 5.0 mg Se/kg. Se content in blood and liver, liver panel tests, blood glucose, total antioxidant capacity (TAC), the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were analysed. Liver and duodenum were subjected to histopathology examination. The weight gain of rats showed no differences between tested groups. Se content in blood was higher in all treated groups compared to the control group. The liver concentration of Se in the treated groups varied in the range from 222 to 238 ng/g. No differences were observed in the activity of AST (aspartate aminotransferase), ALP (alkaline phosphatase) and TAS (total antioxidant status). A significant decrease in ALT activity compared to the control group was observed in the treated groups. GPx activity varied from 80 to 88 U/mL through tested groups. SOD activity in liver was decreased in the SeNP-treated group with 5 mg Se/kg (929 ± 103 U/mL). Histopathological examination showed damage to the liver parenchyma and intestinal epithelium in a dose-dependent manner. This study suggests that short-term SeNP supplementation can be safe and beneficial in Se deficiency or specific treatment.