Vanadium and cadmium in vivo effects in teleost cardiac muscle: metal accumulation and oxidative stress markers

An integrative perspective on fish health: Environmental and anthropogenic pathways affecting fish stress

Multifactorial studies assessing the cumulative effects of natural and anthropogenic stressors on individual stress response are crucial to understand how organisms and populations cope with environmental change. We tested direct and indirect causal pathways through which environmental stressors affect the stress response of wild gilthead seabream in Mediterranean costal lagoons using an integrative PLS-PM approach. We integrated information on 10 environmental variables and 36 physiological variables into seven latent variables reflecting lagoons features and fish health. These variables concerned fish lipid reserves, somatic structure, inorganic contaminant loads, and individual trophic and stress response levels. This modelling approach allowed explaining 30 % of the variance within these 46 variables considered. More importantly, 54 % of fish stress response was explained by the dependent lagoon features, fish age, fish diet, fish reserve, fish structure and fish contaminant load latent variables included in our model. This integrative study sheds light on how individuals deal with contrasting environments and multiple ecological pressures.

Biological Consequences of Vanadium Effects on Formation of Reactive Oxygen Species and Lipid Peroxidation

Lipid peroxidation (LPO), a process that affects human health, can be induced by exposure to vanadium salts and compounds. LPO is often exacerbated by oxidation stress, with some forms of vanadium providing protective effects. The LPO reaction involves the oxidation of the alkene bonds, primarily in polyunsaturated fatty acids, in a chain reaction to form radical and reactive oxygen species (ROS). LPO reactions typically affect cellular membranes through direct effects on membrane structure and function as well as impacting other cellular functions due to increases in ROS. Although LPO effects on mitochondrial function have been studied in detail, other cellular components and organelles are affected. Because vanadium salts and complexes can induce ROS formation both directly and indirectly, the study of LPO arising from increased ROS should include investigations of both processes. This is made more challenging by the range of vanadium species that exist under physiological conditions and the diverse effects of these species. Thus, complex vanadium chemistry requires speciation studies of vanadium to evaluate the direct and indirect effects of the various species that are present during vanadium exposure. Undoubtedly, speciation is important in assessing how vanadium exerts effects in biological systems and is likely the underlying cause for some of the beneficial effects reported in cancerous, diabetic, neurodegenerative conditions and other diseased tissues impacted by LPO processes. Speciation of vanadium, together with investigations of ROS and LPO, should be considered in future biological studies evaluating vanadium effects on the formation of ROS and on LPO in cells, tissues, and organisms as discussed in this review.

Structural Characterization of Polysaccharides from Coriandrum sativum Seeds: Hepatoprotective Effect against Cadmium Toxicity In Vivo

Coriandrum sativum is one of the most widespread curative plants in the world, being vastly cultivated in arid and semi-arid regions as one of the oldest spice plants. The present study explored the extraction of polysaccharides from Coriandrum sativum seeds and the evaluation of their antioxidant potential and hepatoprotective effects in vivo. The polysaccharide from coriander seeds was extracted, and the structural characterization was performed by FT-IR, UV-vis, DSC, NMR (1D and 2D), GC-MS, and SEC analysis. The polysaccharide extracted from Coriandrum sativum (CPS) seeds was characterized to evaluate its antioxidant and hepatoprotective capacities in rats. Results showed that CPS was composed of arabinose, rhamnose, xylose, mannose, fructose, galactose, and glucose in molar percentages of 6.2%, 3.6%, 8.8%, 17.7%, 5.2%, 32.9%, and 25.6%, respectively. Further, CPS significantly hindered cadmium-induced oxidation damage and exercised a protective effect against Cd hepatocytotoxicity, with a considerable reduction in MDA production and interesting CAT and SOD enzyme levels. Results suggest that CPS might be employed as a natural antioxidant source.

An integrated biomarker assessment of biochemical responses in a freshwater fish species after vanadium pentoxide (V2O5) exposure

Vanadium (V) is a toxicant becoming increasingly concentrated in freshwater with the potential to affect aquatic organisms. Vanadium pentoxide (V₂O₅), accumulated in fish, can act as an oxidizing agent and cause oxidative damage. To determine the effects of V₂O₅ on exposed adult Oreochromis mossambicus, acute exposure experiments were conducted. Bioaccumulation and biomarker analyses were performed on various excised tissues of the exposed fish. As expected, accumulated V concentrations in the gills increased as the exposure concentration increased. Gill tissue accumulated more vanadium than muscle tissue. Metallothionein content increased in the highest concentrations compared to the lower concentrations, therefore showing that metallothionein proteins were attempting to sequester V₂O₅ in the tissues. Superoxide dismutase (SOD) showed an excitation at lower concentrations and inhibition as the exposure concentrations increased, possibly due to ROS detoxification. Catalase activity decreased from the first exposure concentration to the last concentration; this could have been due to SOD compensation. Protein carbonyl concentration decreased as the concentrations of V₂O₅ increased, indicating an inhibition of protein oxidation. The IBRv2 comparison revealed the biochemical responses caused by V₂O₅ more effectively than traditional statistical analysis.

Occurrence and Health Risks of Heavy Metals in Drinking Water of Self-Supplied Wells in Northern China

Self-supplied wells, an important water resource in remote and scattered regions, are commonly deteriorated by environmental pollution and human activity. In this study, 156 self-supplied well-water samples were collected from remote and scattered areas of Inner Mongolia (NMG), Heilongjiang (HLJ), and the suburbs of Beijing (BJ) in Northern China. Twenty-four heavy metals were identified by using the inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES), and the associated human health risks were assessed by using standards of the US Environmental Protection Agency (US EPA). The concentrations of four heavy metals (As, Fe, Mn, and Tl) in HLJ, one heavy metal (Tl) in BJ, and ten heavy metals (Al, As, B, Cr, Fe, Mn, Mo, Se, Tl, and Zn) in NMG exceeded the limits set by China or the World Health Organization (WHO). The total carcinogenic risk (TCR) and total non-carcinogenic risk (THQ) exceeding set limits mainly occurred in NMG, compared to HLJ and BJ. Moreover, As accounted for 97.87% and 60.06% of the TCR in HLJ and BJ, respectively, while Cr accounted for 70.83% of the TCR in NMG. The TCR caused by Cd in all three areas had a negligible hazard (<10^-4). As accounted for 51.11%, 32.96%, and 40.88% of the THQ in HLJ, BJ, and NMG, respectively. According to the results of the principal component analysis, heavy metals in well water from HLJ and NMG mainly originated from mixed natural processes and anthropogenic sources, whereas, in BJ, most heavy metals probably originated from natural sources. In the future, long-term monitoring of heavy metals in water from self-supplied wells should be conducted for an extensive range of well-water sites, and well water with high As contamination should be monitored more and fully assessed before being used as a drinking-water source.

Determination of the geographical origin of Trachinotus ovatus and Pampus argenteus in China by multi-element and stable isotope analysis

This study aimed to determine whether Trachinotus ovatus and Pampus argenteus could be differentiated by multi-element composition or stable isotope ratio analysis of δ¹³C and δ¹⁵N. The multi-element analysis values of a total of 60 Pampus argenteus samples from three sites and 60 Trachinotus ovatus samples from four sites around China were determined, and the other 60 samples of Pampus argenteus and 51 samples of Trachinotus ovatus were tested by principal component analysis (PCA) to estimate the accuracy of origin identification. The results showed that the cross-validation accuracy rate is 92.2% for the Pampus argenteus and 98.3% for the Trachinotus ovatus. Stable isotope analysis of δ¹³C and δ¹⁵N also can distinguish Trachinotus ovatus from different geographical origins. These results showed that the usefulness of multi-element and stable isotope analysis as indicators for authenticating the geographical origin of two pomfrets in China.

Single and Mixture Toxicity of Boron and Vanadium Nanoparticles in the Soil Annelid Enchytraeus crypticus: A Multi-Biomarker Approach

The increased use and production of new materials has contributed to Anthropocene biodiversity decrease. Therefore, a careful and effective toxicity evaluation of these new materials is crucial. However, environmental risk assessment is facing new challenges due to the specific characteristics of nanomaterials (NMs). Most of the available ecotoxicity studies target the aquatic ecosystems and single exposures of NMs. The present study evaluated Enchytraeus crypticus survival and reproduction (28 days) and biochemical responses (14 days) when exposed to nanoparticles of vanadium (VNPs) and boron (BNPs) (single and mixture; tested concentrations: 10 and 50 mg/kg). Although at the organism level the combined exposures (VNPs + BNPs) did not induce a different toxicity from the single exposures, the biochemical analysis revealed a more complex picture. VNPs presented a higher toxicity than BNPs. VNPs (50 mg/kg), independently of the presence of BNPs (additive or independent effects), caused a decrease in survival and reproduction. However, acetylcholinesterase, glutathione S-transferase, catalase, glutathione reductase activities, and lipid peroxidation levels revealed alterations in neurotoxicity, detoxification and antioxidant responses, depending on the time and type of exposure (single or mixture). The results from this study highlight different responses of the organisms to contaminants in single versus mixture exposures, mainly at the biochemical level.

Doxycycline: An Antibiotic Attenuates Oxidant Stress, Perturbation of Lipid Metabolites, and Antioxidants against Vanadium Toxicity in Rat Hepatocytes

Background The liver is target following exposure to pentavalent vanadium (V5+). Doxycycline is an antioxidant that prevents the progression of disease through inhibition of lipid peroxidation.

Aim The present study was designed to evaluate the protective effects of doxycycline against vanadium-induced hepatoxicity.

Methods Sixty two male Sprague-Dawley rats (250–300 g) were equally divided into the following four groups: control group (received 0.2 mL of physiological saline), doxycycline control group (received 4 mg/kg body weight on day 1 and 2 mg/kg body weight daily thereafter), vanadium group (received elemental vanadium 1.5 mg/kg-body weight in distilled water), and concomitantly treated group (doxycycline + vanadium) received (doxycycline 4 mg/kg body weight on day 1 and 2 mg/kg body weight thereafter + vanadium 1.5 mg/kg body weight), all given orally for 10 consecutive days. The rats were sacrificed by decapitation 24 hours after the last dose. The liver was removed rapidly and processed for the evaluation of metabolic variables: phospholipids, cholesterol, cerebrosides, gangliosides, reduced glutathione (GSH), vitamin C, calcium, acetylcholinesterase enzyme, and lipid peroxidation.

Results Vanadium administration significantly reduced (−60 g) the body weight and significantly increased (+28%) the relative liver weight compared with controls. The rats exhibited neurological function deficits. Vanadium administration decreased the concentrations of metabolic variables compared with controls, cerebrosides (−50%), cholesterol (−39%), phospholipids (−18%), GSH (−45%), and inhibited acetylcholinesterase enzyme (–48%). Gangliosides (+ 38%), vitamin C (+ 20%), and calcium (+ 80%) were increased together with an enhancement (+64%) in lipid peroxidation. The combined treatment (vanadium and doxycycline) significantly increased (+25 g) the body weight and relative liver weight of rat was significantly reduced (+5%) compared with vanadium administered group. The levels of metabolic variables were significantly reversed in this group in the following order: cholesterol (+17%), phospholipids (+7%), vitamin C (−14%), acetylcholinesterase enzyme activity (−27%) together with inhibition (−16%) of lipid peroxidation. All levels were (p < 0.05). Doxycycline presented no effect on the levels of GSH, cerebrosides, and gangliosides.

Conclusion Results of this study suggested vanadium-induced oxidation of lipids and sphingolipids in hepatocytes and much of GSH was consumed against high production of reactive oxygen species. Doxycycline protected against vanadium-induced oxidative damage that could be attributed to its free radical scavenging effects on membrane-bound lipids and acetylcholinesterase enzyme.

Toxicity of boron and vanadium nanoparticles on Danio rerio embryos - Phenotypical, biochemical, and behavioral alterations

Engineered nanoparticles (NPs) are emerging contaminants of concern and it is important to understand their environmental behavior and ecological risks to exposed organisms. Despite their ubiquitous presence in the environment, there is little information about the hazards of certain NPs, such as boron (BNPs) and vanadium (VNPs). The aim of the present research was to investigate the effects of commercial BNPs and VNPs (80 to 100 nm) to zebrafish embryos, at different levels of biological organization. A range of nominal concentrations for both NPs (0, 0.01, 0.1, 1, and 10 mg/L) was tested. Due to the presence of triton X-100 in the NPs' stock dispersions, an additional control group was included (0.001% triton X-100). Survival, hatching, and malformations of embryos were assessed for 96 hours (h) exposure. Locomotor behavior was evaluated at 120 h. Furthermore, embryos were exposed to 0, 1, and 10 mg/L of NPs to evaluate a set of biomarker responses after 96 h: cholinesterase (ChE) and glutathione S-transferase (GST) activities, total glutathione (TG) and energy budgets levels. VNPs induced malformations (10 mg/L), hyperactivity (10 mg/L), erratic swimming (0.01 mg/L), altered swimming pattern (>0.01 mg/L), delayed hatching (10 mg/L) and altered biochemical responses involved in antioxidant defense (GST and TG at >1 mg/L), neurotransmission (ChE at 10 mg/L) and energy metabolism (lipids at >1 mg/L and carbohydrates at 10 mg/L). BNPs caused malformations (10 mg/L), affected swimming pattern (>0.01 mg/L), induced erratic swimming (10 mg/L) and decreased TG content and GST activity (>1 mg/L). At the same concentrations, VNPs affected a greater number of endpoints than BNPs, demonstrating a greater toxicity to zebrafish embryos. The present study shows that BNPs and VNPs may affect aquatic organisms, albeit at relatively great non-environmentally relevant concentrations, reinforcing the importance of the risk assessment of different NPs.

Rationalizing the Decavanadate(V) and Oxidovanadium(IV) Binding to G-Actin and the Competition with Decaniobate(V) and ATP

The experimental data collected over the past 15 years on the interaction of decavanadate(V) (V₁₀O₂₈^6-; V₁₀), a polyoxometalate (POM) with promising anticancer and antibacterial action, with G-actin, were rationalized by using several computational approaches (docking, density functional theory (DFT), and molecular dynamics (MD)). Moreover, a comparison with the isostructural and more stable decaniobate(V) (Nb₁₀O₂₈^6-; Nb₁₀) was carried out. Four binding sites were identified, named α, β, γ, and δ, the site α being the catalytic nucleotide site located in the cleft of the enzyme at the interface of the subdomains II and IV. It was observed that the site α is preferred by V₁₀, whereas Nb₁₀ is more stable at the site β; this indicates that, differently from other proteins, G-actin could contemporaneously bind the two POMs, whose action would be synergistic. Both decavanadate and decaniobate induce conformational rearrangements in G-actin, larger for V₁₀ than Nb₁₀. Moreover, the binding mode of oxidovanadium(IV) ion, V^IVO²⁺, formed upon the reduction of decavanadate(V) by the -SH groups of accessible cysteine residues, is also found in the catalytic site α with (His161, Asp154) coordination; this adduct overlaps significantly with the region where ATP is bound, accounting for the competition between V₁₀ and its reduction product V^IVO²⁺ with ATP, as previously observed by EPR spectroscopy. Finally, the competition with ATP was rationalized: since decavanadate prefers the nucleotide site α, Ca²⁺-ATP displaces V₁₀ from this site, while the competition is less important for Nb₁₀ because this POM shows a higher affinity for β than for site α. A relevant consequence of this paper is that other metallodrug-protein systems, in the absence or presence of eventual inhibitors and/or competition with molecules of the organism, could be studied with the same approach, suggesting important elements for an explanation of the biological data and a rational drug design.

Effects of melatonin on cadmium accumulation and haematological parameters in cadmium intoxicated Prussian carp ( Carassius gibelio B.)

The present study was performed to determine the effect of melatonin on cadmium accumulation and haematological parameters changes in females of Prussian carp (Carassius gibelio B.). The fish were exposed to a sublethal concentration of cadmium (0.4 and 4.0 mg/L) without or with melatonin implant (containing 18 mg melatonin hormone) for 1, 4, 7, 10 and 13 weeks. After the 7th week, Cd-exposed fish were divided into two groups. The first group of fish were subjected to depuration in clear water, while the second group remained exposed to the same concentrations of cadmium. After the 10th and 13th weeks of exposure the kidney, spleen, heart and blood were taken in order to determine the cadmium concentration and to analyse haematological parameters. The results of this study showed an increase in the concentration of cadmium in the tissues and blood in fish exposed to the highest dose (4.0 mg/L) of cadmium in water with a dependence on the exposure duration. Additionally, it was shown that melatonin administration reduced the cadmium concentration in the tissues and blood, and melatonin had a protective effect against cadmium accumulation. Moreover, the results showed a significant increase in blood parameters (RBC, Ht and Hb) in fish treated with the highest dose of cadmium. However, implantation of melatonin in cadmium-treated fish resulted in marked improvements in haematological parameters. Thus, melatonin can be a good implementation to alleviate, at least partially, the toxicity of cadmium.

Protective effect assessment of Moringa oleifera against cadmium-induced toxicity in HCT116 and HEK293 cell lines

The cadmium (Cd) is considered one of the widespread toxic metals in the aquatic and terrestrial environments, which is due to its long half-life, non-degradable characteristic, and toxicity. Aqueous extract of freeze-dried Moringa oleifera (Moringaceae family) leaves was examined for protective effect and antioxidant power against Cd toxicity. The results revealed that Moringa aqueous extract (MAE) has contents of total polyphenols and flavonoids about 30.14 mg GAE/g and 18.35 mg QE/g respectively. Furthermore, phenolic compounds in leaves of Moringa were studied using a high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Results showed that the largest number of phenolic compounds determined in leaves of Moringa belongs to flavonoids. Moreover, biological properties were determined by radical scavenging capacity (DPPH) and ferric-reducing power (FRAP). Cytoprotective effect and antioxidant power of Moringa extract were assessed using the mitochondrial activity testing method (MTT test), malondialdehyde (MDA), and reactive oxygen species (ROS) production. Results indicate that Moringa aqueous extract have a significant (i) proliferative, (ii) antioxidant, and (iii) cytoprotective effect on HCT116 and HEK293 cells against metal toxicity.

Carbamazepine, cadmium chloride and polybrominated diphenyl ether-47, synergistically modulate the expression of antioxidants and cell cycle biomarkers, in the marine fish cell line SAF-1

A wide range of contaminants, industrial by-products, plastics, and pharmaceutics belonging to various categories, have been found in sea water. Although these compounds are detected at concentrations that might be considered as sub-lethal, under certain conditions they could act synergistically producing unexpected effects in term of toxicity or perturbation of biochemical markers leading to standard pathway. In this study, the Sparus aurata fibroblast cell line SAF-1, was exposed to increasing concentrations of carbamazepine (CBZ), polybrominated diphenyl ether 47 (BDE-47) and cadmium chloride (CdCl₂) until 72 h, to evaluate the cytotoxicity and the expression of genes related to antioxidant defense, cell cycle and energetic balance. In general, both vitality and gene expression were affected by the exposure to the different toxicants, in terms of antioxidant defense and cell cycle control, showing the most significant effects in cells exposed to the mixture of the three compounds, respect to the single compounds separately. The synergic effect of the compounds on the analyzed biomarkers, underlie the potential negative impact of the contaminants on health of marine organisms.

Vanadium and Oxidative Stress Markers - In Vivo Model: A Review

This review article is an attempt to summarize the current state of knowledge of the impact of Vanadium (V) on Oxidative Stress (OS) markers in vivo. It shows the results of our studies and studies conducted by other researchers on the influence of different V compounds on the level of selected Reactive Oxygen Species (ROS)/Free Radicals (FRs), markers of Lipid peroxidation (LPO), as well as enzymatic and non-enzymatic antioxidants. It also presents the impact of ROS/peroxides on the activity of antioxidant enzymes modulated by V and illustrates the mechanisms of the inactivation thereof caused by this metal and reactive oxygen metabolites. It also focuses on the mechanisms of interaction of V with some nonenzymatic compounds of the antioxidative system. Furthermore, we review the routes of generation of oxygen-derived FRs and non-radical oxygen derivatives (in which V is involved) as well as the consequences of FR-mediated LPO (induced by this metal) together with the negative/ positive effects of LPO products. A brief description of the localization and function of some antioxidant enzymes and low-molecular-weight antioxidants, which are able to form complexes with V and play a crucial role in the metabolism of this element, is presented as well. The report also shows the OS historical background and OS markers (determined in animals under V treatment) on a timeline, collects data on interactions of V with one of the elements with antioxidant potential, and highlights the necessity and desirability of conducting studies of mutual interactions between V and antioxidant elements.

Response of vanadium bioaccumulation in tissues of Mugil cephalus (Linnaeus 1758)

Vanadium accumulation levels in different tissues (muscle and organs) of the striped mullet Mugil cephalus (Linnaeus, 1758) and possible relationships with blood parameters were evaluated in a Natural Protected Area (Lake Faro, Sicily, Italy), during the winter of 2017. Hematological parameters (red blood cell, RBC; white blood cell, WBC; hemoglobin concentration, Hb; hematocrit, Hct; mean corpuscular volume, MCV; mean corpuscular hemoglobin, MCH; mean corpuscular hemoglobin concentration, MCHC; thrombocytes, TC), biometric indices (weight, total and fork length), and vanadium levels in muscles and organs (gills, liver, stomach and intestine) were determined. Statistical analyses showed significant differences in concentrations of vanadium of the analyzed tissue of M. cephalus and a positive relationship between vanadium concentration in the liver and some hematological parameters (RBC, Hb and Hct) and biometric indices. Our results underline the importance of fish blood parameters as sensitive indicators of toxic impact of environmental factors such as metals. This study, focusing on an ongoing topic, represents a valuable contribution to research concerning the monitoring and prevention of vanadium pollution in aquatic organisms and environments.

Chemistry, Alpha-glucosidase and Radical Scavenging Properties of Uranyl(VI) Hydrazide Complexes

BACKGROUND

Antioxidant, anti-inflammatory, antiviral and antitumoral activities among others are essential characteristics in the development of novel therapeutic compounds. Acid hydrazides can form complexation with certain metal ions that positively enhance these biological characteristics.

OBJECTIVE

Five new complexes of uranium with hydrazide ligands were synthesized at room temperature.

METHODS

The characterization was done by spectroscopic methods (ESI-Mass, IR, 1H-NMR, 13CNMR), CHN analysis and conductivity measurements. Metal complexes along with their respective ligands were further screened for their antioxidant (DPPH, superoxide and nitric oxide free radicals) properties and enzyme inhibition (α-glucosidase) activities.

RESULTS

Elemental and spectral data indicate octahedral geometry around uranyl (UO2 2+) species. Magnetic moments indicate the diamagnetic nature of uranyl(VI) ion in the complex in solid state. IC50 values showed potential antioxidant behavior of uranyl complexes demonstrating interesting structure-activity relationships. In general, hydrazide ligands were not active against superoxide and nitric oxide radicals while varying degree of results were observed against DPPH radical whereas all uranyl-complexes showed promising radical scavenging activities against all of them. Promising inhibitory potential was displayed by UO2 +2 hydrazide complexes against α- glucosidases whereas free hydrazide ligands were inactive.

CONCLUSION

Structure function relationship demonstrates that the nature of ligand, position of substituent, electronic and steric effects are significant factors affecting the radical scavenging and enzyme inhibition activities of the compounds.

Forensic toxicological study on adipocere formation in submerged cadavers of female albino rats intoxicated with cadmium

There is a dearth of information on the mutual interaction between metal intoxication and adipocere formation. Herein, 40 adult female albino rats were distributed into two equal groups, one used as control while the other orally administered single dose of cadmium chloride (CdCl2) 225 mg/kg·bw (LDmin). Control group was killed by cervical dislocation. Half of dead rats of both groups were subjected for determination of iodine value and estimation of cadmium (Cd) residues while the other half of both groups were submerged in opened glass container previously filled with 4 L dechlorinated tap water kept in closed room with an open air access (one cadaver/container). Gross morphological changes of submerged cadavers were recorded weekly along the experiment. At the end of the experiment, after 3 months, samples were collected again for iodine value determination and estimation of Cd residues. The obtained results revealed the depressant effect of Cd toxicity on development of adipocere. Cd residues were found in different tissues of cadavers at time of death with the highest amount in the intestines followed by the liver and kidneys, then lungs, adipose tissue, muscles, and finally the bones. After 3 months of water submersion, tissues exhibited significant decrease in the amount of Cd residues but to a limit that was still detected. This study concluded the possibility of detection of Cd residues even after adipocere formation. Additionally, it shed light on the possibility of the interference of environmental pollution with the natural rate of decomposition especially adipocere formation.

The antibacterial activity of polyoxometalates: structures, antibiotic effects and future perspectives

Polyoxometalates (POMs) are, mostly anionic, metal oxide compounds that span a wide range of tunable physical and chemical features rendering them very interesting for biological purposes, an continuously emerging but little explored field. Due to their biological and biochemical effects, including antitumor, -viral and -bacterial properties, POMs and POM-based systems are considered as promising future metallodrugs. In this article, we focus on the antibacterial activity of POMs and their therapeutic potential in the battle against bacteria and their increasing resistance against pharmaceuticals. Recent advances in the synthesis of POMs are highlighted, with emphasis on the development and properties of biologically active POM-based hybrid and nanocomposite structures. By analysing the antibacterial activity and structure of POMs, putative mode of actions are provided, including potential targets for POM-protein interactions, and a structure-activity-relationship was established for a series of POMs against two bacteria, namely Helicobacter pylori and Streptococcus pneumoniae.

Combined effects of temperature and metal exposure on the fatty acid composition of cell membranes, antioxidant enzyme activities and lipid peroxidation in yellow perch (Perca flavescens)

The aim of this study was to investigate the combined effects of temperature and metal contamination (cadmium and nickel) on phospholipid fatty acid composition, antioxidant enzyme activities and lipid peroxidation in fish. Yellow perch were acclimated to two different temperatures (9°C and 28°C) and exposed either to Cd or Ni (respectively 4μg/L and 600μg/L) for seven weeks. Superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase activities and glutathione concentration were measured as indicators of antioxidant capacities, while malondialdehyde concentration was used as an indicator of lipid peroxidation. Poikilotherms including fish counteract the effects of temperature on phospholipid fatty acid ordering by remodelling their composition to maintain optimal fluidity. Accordingly, in our study, the fatty acid composition of yellow perch muscle at 9°C was enhanced in monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) compared to fish maintained at 28°C, in agreement with the theory of homeoviscous adaptation. Using ratios of various fatty acids as surrogates for desaturase and elongase activities, our data suggests that modification of the activity of these enzymes is responsible for the thermal acclimation of phospholipid fatty acid profiles. However, this response was altered under Ni and Cd exposure: PUFA decreased (specifically n-6 PUFA) while the proportion of saturated fatty acids increased at 9°C, whereas at 28°C, PUFA increased to proportions exceeding those observed at 9°C. Lipid peroxidation could be observed under all experimental conditions. Both enzymatic and non-enzymatic antioxidant defense systems acted cooperatively to cope with oxidative stress leading to lipid peroxidation, which was not affected by temperature acclimation as indicated by malondialdehyde concentration, in spite of a higher polyinsaturation in cold-acclimated fish which would be predicted to increase their vulnerability to peroxidation. However, in warm-acclimated, Ni-exposed fish, in which the highest proportion of PUFA was observed, lower concentrations of malondialdehyde were measured, suggesting an overcompensation of antioxidant mechanisms in these fish which could represent a substantial metabolic cost and explain their lower condition.

Combined effects of cadmium and salinity on juvenile Takifugu obscurus: cadmium moderates salinity tolerance; salinity decreases the toxicity of cadmium

Obscure puffer Takifugu obscurus, a species of anadromous fish, experiences several salinity changes in its lifetime. Cadmium (Cd) is a toxic heavy metal that can potentially induce oxidative stress in fish. The present study aimed to detect the combined effects of Cd (0, 5, 10, 20 and 50 mg L(-1)) and salinity (0, 15 and 30 ppt) on juvenile T. obscurus. Results showed the juveniles could survive well under different salinities; however, with Cd exposure, the survival rates significantly decreased at 0 and 30 ppt. At 15 ppt, tolerance to Cd increased. Cd exposure clearly induced oxidative stress, and the responses among different tissues were qualitatively similar. Salinity acted as a protective factor which could reduce the reactive oxygen species and malondialdehyde levels. In addition, salinity could enhance the antioxidant defense system, including superoxide dismutase, catalase and glutathione. Na(+)/K(+)-ATPase activity significantly decreased under Cd exposure in gill, kidney and intestine. These findings indicated that Cd could moderate the adaptability of juvenile T. obscurus to high salinity and low salinity played a protective role upon Cd exposure. Thus, the role of salinity should be considered when evaluating the effect of heavy metals on anadromous and estuarine fishes.

Pituitary Adenylate Cyclase-Activating Polypeptide Reverses Ammonium Metavanadate-Induced Airway Hyperresponsiveness in Rats. Oxid Med Cell Longev. 2015;2015:787561. [PMID: 26199679 PMCID: PMC4496651 DOI: 10.1155/2015/787561]

The rate of atmospheric vanadium is constantly increasing due to fossil fuel combustion. This environmental pollution favours vanadium exposure in particular to its vanadate form, causing occupational bronchial asthma and bronchitis. Based on the well admitted bronchodilator properties of the pituitary adenylate cyclase-activating polypeptide (PACAP), we investigated the ability of this neuropeptide to reverse the vanadate-induced airway hyperresponsiveness in rats. Exposure to ammonium metavanadate aerosols (5 mg/m³/h) for 15 minutes induced 4 hours later an array of pathophysiological events, including increase of bronchial resistance and histological alterations, activation of proinflammatory alveolar macrophages, and increased oxidative stress status. Powerfully, PACAP inhalation (0.1 mM) for 10 minutes alleviated many of these deleterious effects as demonstrated by a decrease of bronchial resistance and histological restoration. PACAP reduced the level of expression of mRNA encoding inflammatory chemokines (MIP-1α, MIP-2, and KC) and cytokines (IL-1α and TNF-α) in alveolar macrophages and improved the antioxidant status. PACAP reverses the vanadate-induced airway hyperresponsiveness not only through its bronchodilator activity but also by counteracting the proinflammatory and prooxidative effects of the metal. Then, the development of stable analogs of PACAP could represent a promising therapeutic alternative for the treatment of inflammatory respiratory disorders.

Expression profiling of the sex-related gene Dmrt1 in adults of the Lusitanian toadfish Halobatrachus didactylus (Bloch and Schneider, 1801)

Doublesex and mab-3 related transcription factor 1 (Dmrt1) gene is a widely conserved gene involved in sex determination and differentiation across phyla. To gain insights on Dmrt1 implication for fish gonad cell differentiation and gametogenesis development, its mRNA was isolated from testis and ovary from the Lusitanian toadfish (Halobatrachus didactylus). The cDNA from Dmrt1 was synthesized and cloned, whereas its quantitative and qualitative gene expression, as well as its protein immunolocalization, were analyzed. A main product of 1.38 kb, which encodes a protein of 295 aa, was reported, but other minority Dmrt1 products were also identified by RACE-PCR. This gene is predominantly expressed in testis (about 20 times more than in other organs or tissues), specially in spermatogonia, spermatocytes and spermatids, as well as in somatic Sertoli cells, indicating that Dmrt1 plays an important role in spermatogenesis. Although Dmrt1 transcripts also seem to be involved in oogenesis development, and it cannot be excluded that toadfish Dmrt1 could be functionally involved in other processes not related to sex.

Effects of maternal cadmium exposure on female reproductive functions, gamete quality, and offspring development in zebrafish (Danio rerio)

Impacts of maternal Cd(2+) exposure on female zebrafish (Danio rerio) were observed in females as well as their offspring. In females, Cd disturbed fecundity and other reproductive functions. In their offspring, it retarded gamete development and growth and influenced gene expression. There was a positive relationship between Cd(2+) contents in ovaries of females and treatment doses of 0-8.9 μM of Cd(2+). The mating rate decreased by 60 % when females were exposed to 8.9-35.6 μM of Cd(2+) for 72 h compared with the control group. It was observed that growth is delayed by one somite stage in maternal-Cd(2+) embryos compared with control embryos, which grew at the sixth-somite stage. The ceratohyal angles of larvae of Cd-exposed adults (maternal Cd(2+)) at 72 h postfertilization (hpf) appeared to have a positive response after doses of maternal Cd. In addition, approximately 30 % of 96-hpf larvae that were treated with a dose of 35.6 μM of maternal Cd(2+) appeared to have pericardial edema. At the 5-hpf stage of maternal Cd(2+) exposure, embryos showed 33 and 37 target genes, respectively, that were significantly downregulated and upregulated as shown by cDNA microarray analysis. A major effect of maternal Cd(2+) exposure on zebrafish embryo genes is that 18.9% of transcription functions were upregulated. In addition, 33.3% of transcripts relative to the function of protein biosynthesis were downregulated. These results showed that maternal Cd(2+) exposure influenced the reproduction ability of females and also caused their embryos to develop with abnormal gene expression.

Accumulation, histopathology and immunotoxicological effects of waterborne cadmium on gilthead seabream (Sparus aurata)

Studies in fish have demonstrated that Cd-exposure produce skeletal deformities and alterations in tissue morphology, enzyme activities, stress response, ion regulation and immune response. In the present work, gilthead seabream (Sparus aurata) specimens were exposed to waterborne Cd (5 μM CdCl2 or 1 mg L(-1)) for 2, 10 or 30 days. Organo-somatic changes, Cd accumulation, liver histology and humoral and cellular immune responses were determined. Results showed that exposure of seabream specimens to Cd induced no alterations on spleen and liver organo-somatic indexes whilst produced progressive deleterious morphological alterations in liver and exocrine pancreas that correlated with the hepatic Cd-accumulation. Regarding the immunotoxicological potential, strikingly, Cd-exposure produced a reduction in the serum complement activity and leucocyte respiratory burst to a significant extent after 10 and 30 days whilst the serum peroxidase activity and leucocyte phagocytosis were increased at different sampling times. On the other hand, serum IgM levels and leucocyte peroxidase activity resulted unaltered. The present results seem to indicate that seabream exposed to Cd in the present conditions suffer toxicity.

Oxidative DNA damage estimated by urinary 8-hydroxy-2'-deoxyguanosine and arsenic in glass production workers

A total of 130 male glass workers, including 33 administrative workers, 18 batch house workers, 42 craftsmen, and 37 melting process workers, were recruited to investigate the potential DNA damage resulting from toxic element exposure. The occupational exposure to trace elements, including arsenic (As), cadmium (Cd), manganese (Mn), nickel (Ni), lead (Pb), and selenium (Se), was estimated by their urinary levels as internal doses. In addition, all participants filled a self-filled questionnaire indicating their individual information. The average levels of urinary As, Cd, Mn, Ni, Pb, Se, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were 282.3 ± 464.6, 3.07 ± 5.39, 3.81 ± 11.43, 81.48 ± 138.9, 18.23 ± 49.61, 165.2 ± 224.9, and 17.21 ± 26.34 μg/g creatinine, respectively. The urinary levels of 8-OHdG and toxic elements were strongly associated with the work nature of the worker, with an exception of Mn and Pb. In contrast, the levels of toxic element were not influenced by age, smoking behavior, and alcohol consumption. The urinary 8-OHdG was found significantly higher in higher internal exposure groups of As, Cd, Ni, and Se. However, the stepwise multiple regression models showed that urinary 8-OHdG was only associated with urinary As and heat stress but inversely with age.

Recent perspectives into biochemistry of decavanadate

The number of papers about decavanadate has doubled in the past decade. In the present review, new insights into decavanadate biochemistry, cell biology, and antidiabetic and antitumor activities are described. Decameric vanadate species (V₁₀) clearly differs from monomeric vanadate (V₁), and affects differently calcium pumps, and structure and function of myosin and actin. Only decavanadate inhibits calcium accumulation by calcium pump ATPase, and strongly inhibits actomyosin ATPase activity (IC₅₀ = 1.4 μmol/L, V₁₀), whereas no such effects are detected with V₁ up to 150 μmol/L; prevents actin polymerization (IC₅₀ of 68 μmol/L, whereas no effects detected with up to 2 mmol/L V₁); and interacts with actin in a way that induces cysteine oxidation and vanadate reduction to vanadyl. Moreover, in vivo decavanadate toxicity studies have revealed that acute exposure to polyoxovanadate induces different changes in antioxidant enzymes and oxidative stress parameters, in comparison with vanadate. In vitro studies have clearly demonstrated that mitochondrial oxygen consumption is strongly affected by decavanadate (IC₅₀, 0.1 μmol/L); perhaps the most relevant biological effect. Finally, decavanadate (100 μmol/L) increases rat adipocyte glucose accumulation more potently than several vanadium complexes. Preliminary studies suggest that decavanadate does not have similar effects in human adipocytes. Although decavanadate can be a useful biochemical tool, further studies must be carried out before it can be confirmed that decavanadate and its complexes can be used as anticancer or antidiabetic agents.

Vanadium compounds induced mitochondria permeability transition pore (PTP) opening related to oxidative stress

Vanadium compounds have been regarded as promising in therapeutic treatment of diabetes and in cancer prevention. In the present work, we studied the effects of vanadium compounds on mitochondria to investigate the mechanisms of toxicity. Mitochondria were isolated from rat liver and incubated with a variety of vanadium compounds, i.e. VOSO(4), NaVO(3), and vanadyl complexes with organic ligands. Our studies indicated that VO(2+), VO(3)(-), VO(acac)(2) and VOcit (1-100microM) could induce mitochondrial swelling in a concentration dependent manner and disrupt mitochondrial membrane potential (Deltapsi(m)) in a time dependent manner, which is quite different from the rapid Deltapsi(m) collapse caused by Ca(2+) or CCCP (carbonyl cyanide m-chlorophenylhydrazone, a mitochondrial uncoupling reagent). Release of cytochrome c (Cyt c) was observed and could be inhibited by cyclosporin A (CsA), an inhibitor of the mitochondrial permeability transition pore (PTP). Interestingly, VOdipic caused release of Cyt c without mitochondrial swelling and Deltapsi(m) disruption, an action previously only observed on the Bax protein, suggesting a potentially role of VOdipic in regulating PTP opening. In addition, all the vanadium compounds tested stimulated mitochondrial production of reactive oxygen species (ROS). Antioxidants, i.e. vitamin C and E, significantly delayed the Deltapsi(m) disruption. Overall, our experimental evidence indicated vanadium compounds exhibited multiple actions on mitochondria. Vanadium compounds did induce oxidative stress on mitochondrial and thus caused PTP opening, which led to collapse of Deltapsi(m) and Cyt c release as the initiation of cell apoptosis.

Determination of metal ion content of beverages and estimation of target hazard quotients: a comparative study

Background

Considerable research has been directed towards the roles of metal ions in nutrition with metal ion toxicity attracting particular attention. The aim of this study is to measure the levels of metal ions found in selected beverages (red wine, stout and apple juice) and to determine their potential detrimental effects via calculation of the Target Hazard Quotients (THQ) for 250 mL daily consumption.

Results

The levels (mean ± SEM) and diversity of metals determined by ICP-MS were highest for red wine samples (30 metals totalling 5620.54 ± 123.86 ppb) followed by apple juice (15 metals totalling 1339.87 ± 10.84 ppb) and stout (14 metals totalling 464.85 ± 46.74 ppb). The combined THQ values were determined based upon levels of V, Cr, Mn, Ni, Cu, Zn and Pb which gave red wine samples the highest value (5100.96 ± 118.93 ppb) followed by apple juice (666.44 ± 7.67 ppb) and stout (328.41 ± 42.36 ppb). The THQ values were as follows: apple juice (male 3.11, female 3.87), stout (male 1.84, female 2.19), red wine (male 126.52, female 157.22) and ultra-filtered red wine (male 110.48, female 137.29).

Conclusion

This study reports relatively high levels of metal ions in red wine, which give a very high THQ value suggesting potential hazardous exposure over a lifetime for those who consume at least 250 mL daily. In addition to the known hazardous metals (e.g. Pb), many metals (e.g. Rb) have not had their biological effects systematically investigated and hence the impact of sustained ingestion is not known.