Antibacterial activity of CuO-Ag Janus like nanoparticles against recombinant strain Escherichia coli.

The toxic action of CuO-Ag Janus particles and a bicomponent mixture of CuO and Ag particles have been studied against a recombinant strain Escherichia coli K12 TG1 with cloned luxCDABE genes of marine bacteria Photobacterium leiognathi 54D10. An original method was used for the preparation CuO-Ag Janus like  nanoparticles by simultaneous electrical explosion of twisted Cu and Ag wires in a mixture of argon and oxygen gases. The bioluminescence inhibition on recombinant strain E. coli shows that CuO-Ag Janus NPs were effective. The concentration by 50% (EC50) for CuO-Ag Janus NPs was 0.03 ± 0.001 mg/ml (p < 0.05). The bioactivity of the bicomponent mixture of CuO and Ag NPs (EC50) was 0.25 ± 0.002 mg/ml (p < 0.05). The effective concentration of CuO-Ag Janus NPs against E. coli was comparatively lower than those of bicomponent mixture CuO and Ag against which explains the higher activity of CuO-Ag Janus NPs. The toxicity values of CuO and Ag as monocomponent nanoparticles were 2-32 times lower compared with the bicomponent nanoparticles. A dose-dependent inhibition of bacterial luminescence developed over time was noted. The result of contact E. coli with CuO-Ag Janus particles was 100% suppression of bacterial luminescence from the first minutes of contact occured starting with a content of 2.0 mg/ml and within the next 180 min. The effect of bioactivity prolonged in the final concentration of nanopowder (EC100 = 0.0625 ± 0.002 mg/ml) (p < 0.05). CuO-Ag Janus particles exhibited more pronounced antibacterial activity compared to CuO, Ag nanoparticles and their mechanical mixture.

Gut Microbiota as a Mediator of Essential and Toxic Effects of Zinc in the Intestines and Other Tissues.

The objective of the present study was to review the existing data on the association between Zn status and characteristics of gut microbiota in various organisms and the potential role of Zn-induced microbiota in modulating systemic effects. The existing data demonstrate a tight relationship between Zn metabolism and gut microbiota as demonstrated in Zn deficiency, supplementation, and toxicity studies. Generally, Zn was found to be a significant factor for gut bacteria biodiversity. The effects of physiological and nutritional Zn doses also result in improved gut wall integrity, thus contributing to reduced translocation of bacteria and gut microbiome metabolites into the systemic circulation. In contrast, Zn overexposure induced substantial alterations in gut microbiota. In parallel with intestinal effects, systemic effects of Zn-induced gut microbiota modulation may include systemic inflammation and acute pancreatitis, autism spectrum disorder and attention deficit hyperactivity disorder, as well as fetal alcohol syndrome and obesity. In view of both Zn and gut microbiota, as well as their interaction in the regulation of the physiological functions of the host organism, addressing these targets through the use of Zn-enriched probiotics may be considered an effective strategy for health management.

Assessment of the toxicity of silicon nanooxide in relation to various components of the agroecosystem under the conditions of the model experiment.

Investigation of SiO2 nanoparticles (NPs) effect on Eisenia fetida showed no toxic effect of the metal at a concentration of 250, 500 and 1000 mg per kg of soil, but conversely, a biomass increase from 23.5 to 29.5% (at the protein level decrease from 60 to 80%). The reaction of the earthworm organism fermentative system was expressed in the decrease in the level of superoxide dismutase (SOD) on the 14th day and in the increase in its activity to 27% on the 28th day. The catalase level (CAT) showed low activity at average element concentrations and increase by 39.4% at a dose of 1000 mg/kg. Depression of malonic dialdehyde (MDA) was established at average concentrations of 11.2% and level increase up to 9.1% at a dose of 1000 mg/kg with the prolongation of the effect up to 87.5% after 28-day exposure. The change in the microbiocenosis of the earthworm intestine was manifested by a decrease in the number of ammonifiers (by 42.01-78.9%), as well as in the number of amylolytic microorganisms (by 31.7-65.8%). When the dose of SiO2 NPs increased from 100 to 1000 mg/kg, the number of Azotobacter increased (by 8.2-22.2%), while the number of cellulose-destroying microorganisms decreased to 71.4% at a maximum dose of 1000 mg/kg. The effect of SiO2 NPs on Triticum aestivum L. was noted in the form of a slight suppression of seed germination (no more than 25%), an increase in the length of roots and aerial organs which generally resulted in an increase in plant biomass. Assessing the soil microorganisms' complex during introduction of metal into the germination medium of Triticum aestivum L., there was noted a decrease in the ammonifiers number (by 4.7-67.6%) with a maximum value at a dose of 1000 mg/kg. The number of microorganisms using mineral nitrogen decreased by 29.5-69.5% with a simultaneous increase in the number at a dose of 50 mg/kg (+ 20%). Depending on NP dose, there was an inhibition of the microscopic fungi development by 18.1-72.7% and an increase in the number of cellulose-destroying microorganisms. For all variants of the experiment, the activity of soil enzymes of the hydrolase and oxidoreductase classes was decreased.

A zeta potential value determines the aggregate's size of penta-substituted [60]fullerene derivatives in aqueous suspension whereas positive charge is required for toxicity against bacterial cells.

BACKGROUND: The cause-effect relationships between physicochemical properties of amphiphilic [60]fullerene derivatives and their toxicity against bacterial cells have not yet been clarified. In this study, we report how the differences in the chemical structure of organic addends in 10 originally synthesized penta-substituted [60]fullerene derivatives modulate their zeta potential and aggregate's size in salt-free and salt-added aqueous suspensions as well as how these physicochemical characteristics affect the bioenergetics of freshwater Escherichia coli and marine Photobacterium phosphoreum bacteria. Dynamic light scattering, laser Doppler micro-electrophoresis, agarose gel electrophoresis, atomic force microscopy, and bioluminescence inhibition assay were used to characterize the fullerene aggregation behavior in aqueous solution and their interaction with the bacterial cell surface, following zeta potential changes and toxic effects. RESULTS: Dynamic light scattering results indicated the formation of self-assembled [60]fullerene aggregates in aqueous suspensions. The measurement of the zeta potential of the particles revealed that they have different surface charges. The relationship between these physicochemical characteristics was presented as an exponential regression that correctly described the dependence of the aggregate's size of penta-substituted [60]fullerene derivatives in salt-free aqueous suspension from zeta potential value. The prevalence of DLVO-related effects was shown in salt-added aqueous suspension that decreased zeta potential values and affected the aggregation of [60]fullerene derivatives expressed differently for individual compounds. A bioluminescence inhibition assay demonstrated that the toxic effect of [60]fullerene derivatives against E. coli cells was strictly determined by their positive zeta potential charge value being weakened against P. phosphoreum cells in an aquatic system of high salinity. Atomic force microscopy data suggested that the activity of positively charged [60]fullerene derivatives against bacterial cells required their direct interaction. The following zeta potential inversion on the bacterial cells surface was observed as an early stage of toxicity mechanism that violates the membrane-associated energetic functions. CONCLUSIONS: The novel data about interrelations between physicochemical parameters and toxic properties of amphiphilic [60]fullerene derivatives make possible predicting their behavior in aquatic environment and their activity against bacterial cells.

The combined effect of ultrafine particles of cobalt and manganese oxides and Origanum vulgare herb extract on ruminal digestion in vitro.

Background and Aim: At present, detailed studies are being conducted to confirm the safety of the use of metal-containing ultrafine particles (UFP) in animal feeding, preventing the possibility of negative effects on productive qualities and physiological state, as well as on the environment and final consumer, that is, humans. Thus, the purpose of this research was to study the safety of cobalt- and manganese-containing UFP (UFP Co3O4, Mn2O3 UFP) together with Origanum vulgare (PB) herb extract in a bioluminescence inhibition test, as well as the effect of this composition on ruminal digestion in vitro. Materials and Methods: The safety of the studied samples was determined using a multifunctional microplate analyzer TECAN Infinite F200 (Tecan Austria GmbH, Austria), recording the luminescence value of the bacterial strain Escherichia coli K12 TG11 (Ecolum, JSC NVO Immunotech, Russia). Dry matter (DM) digestibility studies were performed using the in vitro method on an "artificial rumen" model using an ANKOM Daisy II incubator unit (AD II; USA). The number of protozoa in ruminal fluid was counted in a Goryaev chamber. The bacterial mass was assessed by differential centrifugation followed by drying. This method is based on differences in the sedimentation rate of particles that differ in size and density. Results: UFP Co3O4 and Mn2O3 at concentrations above 1.5 × 10-5 and 1.9 × 10-3 mol/L, respectively, have a pronounced bactericidal effect, suppressing more than 50% of the luminescence of E. coli K12 TG1. The combined use of UFP metals and plant extract increases the luminescence of the test object, indicating its safety. The combined use of UFP and PB increases the digestibility of feed DM in vitro and the number of protozoa in 1 mL of ruminal fluid; however, the combination of UFP Mn2O3 + PB (13.8%) yielded the best result, which is recommended for further in vivo research. Conclusion: Origanum vulgare extract reduces the toxicity of UFP Co3O4 and Mn2O3 in vitro, indicating that their combined use is safer.

Serum Mineral Levels in Dairy Cows Transiting from Feedlot to Pasture.

The objective of the present study was to evaluate trace element and minerals levels in the serum of cows transiting from diets consumed in feedlot or under grazing. A total of 30 healthy 5-6 years old cows of the Red Steppe breed were involved in the study. Blood samples were collected at the end of the feedlot period (end of April) and during the pasture period (end of June). Serum essential trace element and mineral levels were evaluated using inductively coupled plasma mass spectrometry. The obtained data demonstrate that serum K levels in cows during the feedlot period exceeded those in the pasture period by 50%, whereas serum P values in the pasture period were significantly higher than in the feedlot period by 20%. Serum Li levels in cows during the feedlot feeding period were nearly 3-fold higher than the respective values in a pasture period. In addition, serum B, Sr, and Zn concentrations in cows during a pasture period exceeded those observed upon feedlot feeding by 38%, 40%, and 13%, respectively. In contrast, serum I and V levels in a feedlot period were 32% and 77% higher when compared to the respective values in a pasture period. Multiple regression analysis demonstrated that Cr, Cu, I, Na, and V are positively associated with feedlot feeding. At the same time, serum Zn and to a lesser extent Sr values were directly associated with the pasture period. Therefore, the results of the present study demonstrated that feedlot and pasture rations have a significant impact on trace element and mineral metabolism in dairy cows.

Elemental composition of the hair and milk of black-spotted cows and its relationship with intestinal microbiome reorganization.

Background and Aim: The cattle breeding system is facing severe problems associated with the increased negative impact of various human activity areas on the environment and the bodies of farm animals. The use of heavy metals in different production areas leads to their accumulation in the environment due to the ingestion of animals and humans through animal products. This study aimed to assess the elemental composition of the hair and milk of black-spotted cows and to identify the relationship between the content of toxic and essential elements and the state of the intestinal microbiome. Materials and Methods: The element status was estimated by studying the chemical composition of the biosubstrates using inductively coupled plasma-mass spectroscopy. Based on the analysis of hair, the elemental composition, and the use of the coefficient of toxic load, two groups of animals were formed: Group I, which included cows with a lower load factor, and Group II, which included cows with a higher load factor. Results: An increase in the heavy metal concentrations in the hair and milk of animals in Group II was observed. The As, Fe, Pb, Al, Co, Ni, and V concentrations in the hair of cows from Group II increased relative to Group I by 19%, 29%, 24.5%, 32.3%, 35.6%, 21.5%, and 18.2%, respectively. There was a significant increase in the level of Fe by 11.5%, Cr by 8.25%, Mn by 17.6%, Pb by 46.1%, and Cd by 25% in Group II compared with Group I in the assessment of elemental milk composition. There were no apparent changes in the intestinal microbiome of Group II. Conclusion: Some heavy metals were accumulated in the bodies and milk of animals. This shows a high probability of heavy metals causing harm to the health of animals and humans.

Serum and Hair Trace Element and Mineral Levels in Dairy Cows in Relation to Daily Milk Yield.

The objective of the present study was to assess hair and serum trace element and mineral levels in dairy cows in relation to daily milk yield. A total of 70 healthy 5-6-year-old Simmental cows were divided into two groups (n = 35) with high and low daily milk yield using median as a cut-off value. Hair and serum trace element and mineral content was evaluated using inductively coupled plasma mass-spectrometry. A nearly twofold difference in daily milk yield (43.8 ± 9.7 vs 21.3 ± 7.1 L/day, p < 0.001) was significantly associated with 11% lower hair Cu (p = 0.043) and 35% higher Se levels (p = 0.058) content when compared animals with lower daily milk yield. Serum trace element levels were found to be more tightly associated with milk productivity in dairy cows. Particularly, serum levels of Se and Zn were found to be 73 and 35% higher in cows with higher milk productivity in comparison to animals with lower milk production, respectively. Serum Co levels also tended to increase with higher milk productivity. Serum minerals including Ca, Mg, and P were also found to be higher in highly productive cows by 6%, 14%, and 71%, respectively. The overall regression model based on serum trace element and mineral levels accounted for 38% of daily milk production variability. Generally, improvement of essential trace element and mineral supply, as well as prevention of copper overload in dairy cows, may be considered the potential tool for modulation of milk productivity.

Speciation of Serum Copper and Zinc-Binding High- and Low-Molecular Mass Ligands in Dairy Cows Using HPLC-ICP-MS Technique.

The objective of the present study was assessment of the major copper and zinc species in dairy cow blood serum using a hybrid high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) technique. A total of seventeen 5-6-year-old female Simmental cows, cultivated in the Southern Ural region, were examined. Speciation of serum Cu and Zn was performed using chromatographic PerkinElmer Series 200 system equipped with Agilent Bio SEC-5 Column and docked with NexION 300D mass spectrometer. Analysis of serum 63Cu species revealed four major fractions containing 2.5% (A), 15.6% (B), 75.6% (C), and 11.9% (D) of total copper levels. The revealed fractions could be assigned to tetrameric and dimeric macroglobulin, ceruloplasmin, albumin, and low molecular mass (LMM) copper compounds, respectively. Minor fraction (E) containing <1% of total serum Cu levels may be represented by low-molecular mass Cu species. Speciation analysis also revealed four Zn fractions containing 6.3% (A), 16.9% (B), 71% (C), and 3% (D) of total Zn levels that may be attributed to zinc-bound tetrameric and dimeric macroglobulin, albumin, and Zn-amino acid compounds. Correlation analysis demonstrated that relative levels (%) of Zn-B (dimeric α2-macroglobulin), Zn-C (albumin), and Zn-D (LMM) fractions correlate inversely with Cu-A (monomeric α2-macroglobulin) (r = -0.600), Cu-D (albumin) (r = -0.696), and Cu-C (ceruloplasmin) (r = -0.652), respectively. The obtained data demonstrate the particular features of Zn and Cu transport in dairy cows that may be used for assessment of dietary status of trace elements.

Assessment of the structural reorganization of liver and biochemical parameters of blood serum after introduction of zinc nanoparticles and its oxides.

The demand for nanoparticles of metals and their oxides in medicine and biology is indisputable. To ensure the safe use of the unique capabilities of nanostructures, in particular, essential metals and their oxides, and to further search for ways leveling side effects of toxic effects in biomedical applications, a multifaceted approach to the study of their properties is needed, primarily affecting the effects on the organism level. In this connection, the purpose of the present research was to study the effect of zinc nanoparticles (ZnNPs) and zinc oxide nanoparticles (ZnONPs) on structural reorganization of the liver and morpho-biochemical parameters of rat blood. The test substances exhibit a hepatotoxic effect upon their single intraperitoneal administration to rats. In the experiment, increased activity of gamma glutamyltransferase (GGT) and lactate dehydrogenase (LDH), increased expression of caspase-3, the presence of signs of oxidative stress, inflammation, and capillary-trophic insufficiency, and induction of tumor necrosis factor (TNF-α), and colony stimulating factor 2 (granulocyte-macrophage) (GM-CSF) were registered in the experiment. The level of interferon-γ in the experimental groups tended to decrease in comparison with the control group. The observed effects progressed in time, most noticeably manifested in the case of ZnONPs. Comparing the dosages, ZnNPs are less toxic than ZnONPs.

The effect of iron nanoparticles on performance of cognitive tasks in rats.

To assess the influence of 62.5 ± 0.6 nm iron nanoparticles on the status of central nervous system, a study was conducted on Wistar rats, which were subjected to abdominal injection of the studied nanoparticles at doses of 2 and 14 mg/kg. Based on the analysis of the structural and functional status of the cerebral cortex of rats, behavioral reactions of animals, and the elemental composition of the cerebral cortex, we investigated the nanoparticles' neurotoxic effect, whose degree and nature varied depending on the dosage and the time elapsed after the injection. We identified pathological changes in motor and somatosensory areas of the rats' cerebral cortex and established pronounced changes in the elemental homeostasis of the animals' cerebral cortex in experimental groups. Identified structural changes were accompanied by an increase in exploratory activity, locomotor activity, and emotional status of the animals. At that, these activities were more pronounced in rats, which were administered iron nanoparticles at a dose of 14 mg/kg. By the end of the experiment, the excitation processes prevailed over the inhibition processes that have led to the inhibition of central nervous system activity in experimental animals against the adaptation to stress in rats of the control group.

Silylative Dieckmann-like cyclizations of ester-imides (and diesters).

[Structure: see text] Trialkylsilyl triflates effect cyclization of ester-imides such as 2 to produce adducts such as 4a. Trapping of the in situ generated, nucleophilic ketene acetal (cf. 5a) is a key aspect of the transformation. A range of substrates amenable to this operationally simple reaction is reported. In many instances the levels of diastereoselectivity are very high. Mechanistic points are inferred from spectroscopic observations.

Impact of molybdenum nanoparticles on survival, activity of enzymes, and chemical elements in Eisenia fetida using test on artificial substrata.

The influence of molybdenum oxide nanoparticles (MoO3) on the growth and survival of Eisenia fetida was established. The activity of antioxidant enzymes and changes in concentration of molybdenum in the body of E. fetida were determined. The degree of bacterial bioluminescence inhibition in extracts of substrates and worm was studied using luminescent strain Escherichia coli K12 TG1. The enzymatic activity of substrates before and after exposure with nanoparticles and worms was assessed. Nanoparticles have concentrations of 10, 40, and 500 mg/kg of dry matter, and substrata are made of artificial soil (substrate A) and microcrystalline cellulose (substrate B). Spherical nanoparticles MoO3, yellow in color, with size 92 ± 0.3 nm, Z-potential 42 ± 0.52 mV, molybdenum content 99.8 mass/%, and specific area 12 m(2)/g were used in the study. A significant decrease by 23.3 % in weight was registered (for MoO3 NPs at 500 mg/kg) on substrate A (p ≤ 0.05). On substrate B, the maximum decrease in weight by 20.5, 33.3, and 16.9 % (p ≤ 0.05) was registered at a dose of 10, 40, and 500 mg/kg, respectively; mortality was from 6.6 to 73 %. After the assessment of bacterial bioluminescence inhibition in substrates A and B (extracts) and before worms were put, the toxicity of substrates was established at doses of 40 and 500 mg/kg, expressed in inhibitory concentration (IC) 30 and IC 50 values. Comparatively, on days 7 and 14, after exposure in the presence of E. fetida, no inhibition of bioluminescence was registered in extracts of substrates A and B, indicating the reduction in toxicity of substrates. The initial content of molybdenum in E. fetida was 0.9 ± 0.018 mg/kg of dry matter. The degree of molybdenum accumulation in worm tissue was dependent on the dose and substrate quality. In particular, 2-7 mg/kg of molybdenum accumulated from substrate A, while up to 15 kg/kg of molybdenum accumulated from substrate B (day 7). Molybdenum concentration decreased by 64.8 and 57.4 % at doses 40 and 500 mg/kg, respectively, on day 14. The reaction of antioxidant enzymes was shown in an insignificant increase of glutathione reductase (GSR) and catalase (CAT) at concentrations of 10 and 40 mg/kg in substrate A, followed by the subsequent reduction of their activity at the dose of 500 mg/kg MoO3. The activity of GSR in substrate B against the presence of MoO3 nanoparticles decreased, with significant difference of 33.5 % (p ≤ 0.05) at the dose of 500 mg/kg compared with untreated soil. In experiments with substrate A, an increase of catalase activity was registered for the control sample. The presence of MoO3 nanoparticles at the concentration of 10 mg/kg in the environment promoted enzymatic activity on days 7 and 14, respectively. A further increase of nanoparticle concentration resulted in the decrease of catalase activity with a minimum value at the concentration of MoO3 of 500 mg/kg. In the experiment with substrate B at the concentration of MoO3 nanoparticles of 40 mg/kg, enzymatic activity increases on day 7 of exposure. However, the stimulating effect of nanoparticles stops by day 14 of the experiment and further catalase activity is dose dependent with the smallest value in the experiment with MoO3 having the concentration of 500 mg/kg.

Assessment of morphological and functional changes in organs of rats after intramuscular introduction of iron nanoparticles and their agglomerates.

The research was performed on male Wistar rats based on assumptions that new microelement preparations containing metal nanoparticles and their agglomerates had potential. Morphological and functional changes in tissues in the injection site and dynamics of chemical element metabolism (25 indicators) in body were assessed after repeated intramuscular injections (total, 7) with preparation containing agglomerate of iron nanoparticles. As a result, iron depot was formed in myosymplasts of injection sites. The quantity of muscle fibers having positive Perls' stain increased with increasing number of injections. However, the concentration of the most chemical elements and iron significantly decreased in the whole skeletal muscle system (injection sites are not included). Consequently, it increased up to the control level after the sixth and the seventh injections. Among the studied organs (liver, kidneys, and spleen), Caspase-3 expression was revealed only in spleen. The expression had a direct dependence on the number of injections. Processes of iron elimination from preparation containing nanoparticles and their agglomerates had different intensity.

Evidence for the negative cooperativity of the two active sites within bovine somatic angiotensin-converting enzyme.

The somatic isoform of angiotensin-converting enzyme (ACE) consists of two homologous domains (N- and C-domains), each bearing a catalytic site. We have used the two-domain ACE form and its individual domains to compare characteristics of different domains and to probe mutual functioning of the two active sites within a bovine ACE molecule. The substrate Cbz-Phe-His-Leu (N-carbobenzoxy-L-phenylalanyl-L-histidyl-L-leucine; from the panel of seven) was hydrolyzed faster by the N-domain, the substrates FA-Phe-Gly-Gly (N-(3-[2-furyl]acryloyl)-L-phenylalanyl-glycyl-glycine) and Hip-His-Leu (N-benzoyl-glycyl-L-histidyl-L-leucine) were hydrolyzed by both domains with equal rates, while other substrates were preferentially hydrolyzed by the C-domain. The inhibitor captopril ((2S)-1-(3-mercapto-2-methylpropionyl)-L-proline) bound to the N-domain more effectively than to the C-domain, whereas lisinopril ((S)-N(alpha)-(1-carboxy-3-phenylpropyl)-L-lysyl-L-proline) bound to equal extent with all ACE forms. However, active site titration with lisinopril assayed by hydrolysis of FA-Phe-Gly-Gly revealed that 1 mol of inhibitor/mol of enzyme abolished the activity of either two-domain or single-domain ACE forms, indicating that a single active site functions in bovine somatic ACE. Neither of the k(cat) values obtained for somatic enzyme was the sum of k(cat) values for individual domains, but in every case the value of the catalytic constant of the hydrolysis of the substrate by the two-domain ACE represented the mean quantity of the values of the corresponding catalytic constants obtained for single-domain forms. The results indicate that the two active sites within bovine somatic ACE exhibit strong negative cooperativity.

Bolaforms with fourteen galactose units: a proposed site-directed cohesion of cancer cells.

[structure: see text] The multistep synthesis of a calixarene joined to a second calixarene via a long spacer is described. Since each calixarene bears multiple galactose-based units (known to bind strongly to rat hepatoma cells), there existed the possibility of cross-linking the cancer cells into a network. The compounds did not serve this purpose, a fact potentially correctable by adjusting or rigidifying the spacer. Formation of a "cancer net" around a solid tumor remains a viable approach to retarding growth and/or inhibiting metastasis.

Influence of Cu10x copper nanoparticles intramuscular injection on mineral composition of rat spleen.

Spleen mineral composition was studied for 25 elements using atomic emission and mass spectrometry (AES-ISP and MS-ISP) for the first time by one- and manifold intramuscular injection of Cu10x copper nanoparticles. This was done, because the spleen is considered to be the organ most amenable of immunological defense and sensitive to exposure. The research is new and based on the necessity to check the accumulation of elements, which can result in toxic effects, and also the character of the influence of nanoparticles on the change of the natural fluctuation rhythm, as well as the interrelation between them.