Bisphenol a (BPA) aggravate the adverse effect on physiological and biochemical response in freshwater mussel potomida littoralis.

Bisphenol A (BPA) is a chemical compound extensively employed in plastic manufacturing, and this pollutant has been detected in diverse aquatic organisms, notably bivalves. In order to comprehend the ecological and toxicological consequences of BPA Bisphenol A in these organisms, it is essential to examine the physiological and biochemical effects and identify areas where our understanding is lacking. This knowledge is crucial for determining the environn ental threat posed by bisphenol A and assisting decision-makers in establishing the appropriate priorities. This investigation aimed to assess the impact of BPA on the biochemical and physiological parameters of the freshwater mussel Potomida littoralis. In a laboratory setting, mussels were subjected to two different levels of BPA (20 and 100 µg/L) for a duration of 21 days. Filtration rate was calculated from the clearance of neutral red, fed to mussels at different BPA concentrations. The mussel's filtration rate capacity declined as BPA exposure intensified, potentially due to the mussel's attempt to close its valves and minimize BPA absorption, thus preventing cellular damage. In the digestive gland tissue, key antioxidant and detoxification defenses, including catalase (CAT) activity, glutathione-S-transferase (GST) activity, and levels of H2O2 and glutathione (GSH), were activated, particularly at the 100 µg/L BPA concentration. This activation helped protect against lipid damage at higher BPA concentrations. This study underscores the significance of preventing and regulating BPA release into the environment to avert detrimental consequences for aquatic ecosystems.

The pharmaceutical triclosan induced oxidative stress and physiological disorder in marine organism and nanoparticles as a potential mitigating tool.

Environmental research plays a crucial role in formulating novel approaches to pollution management and preservation of biodiversity. This study aims to assess the potential harm of pharmaceutical triclosan (TCS) to non-target aquatic organism, the mussel Mytilus galloprovincialis. Furthermore, our study investigates the potential effectiveness of TiO2 and ZnO nanomaterials (TiO2 NPs and ZnO NPs) in degrading TCS. To ascertain the morphology, structure, and stability of the nanomaterials, several chemical techniques were employed. To evaluate the impact of TCS, TiO2 NPs, and ZnO NPs, both physiological (filtration rate (FR) and respiration rate (RR)), antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST)) activities and malondialdehyde (MDA) contents were measured in M. galloprovincialis gills and digestive gland. The mussel's responses varied depending on the contaminant, concentration, and organ, underscoring the significance of compiling these factors in ecotoxicity tests. The main toxic mechanisms of TCS and ZnO NPs at a concentration of 100 µg/L were likely to be a decrease in FR and RR, an increase in oxidative stress, and increased lipid peroxidation. Our findings indicate that a mixture of TCS and NPs has an antagonist effect on the gills and digestive gland. This effect is particularly notable in the case of TCS2 = 100 µg/L combined with TiO2 NP2 = 100 µg/L, which warrants further investigation to determine the underlying mechanism. Additionally, our results suggest that TiO2 NPs are more effective than ZnO NPs at degrading TCS, which may have practical implications for pharmaceutical control in marine ecosystems and in water purification plants. In summary, our study provides valuable information on the impact of pharmaceuticals on non-target organisms and sheds light on potential solutions for their removal from aqueous environments.

Magnetic sporopollenin supported magnesium nanoparticles for removal of tetracycline as an emerging contaminant from water.

Since the release of antibiotics as emerging contaminants into the environmental water can cause severe difficulties for human health, their removal from the water is necessary. In this regard, a novel environmentally friendly adsorbent was developed based on green sporopollenin, which was magnetized and modified with magnesium oxide nanoparticles to produce MSP@MgO nanocomposite. The newly developed adsorbent was applied to remove tetracycline antibiotic (TC) from aqueous media. The surface morphology of the MSP@MgO nanocomposite was characterized using FTIR, XRD, EDX, and SEM techniques. The effective parameters of the removal process were studied, and it was confirmed that the chemical structure of TC was highly affected by changes in pH solution due to different pKa; therefore, the results showed that pH 5 was the optimum. Also, the maximum sorption capacity of MSP@MgO for TC for adsorption was obtained at 109.89 mg.g-1. In addition, the adsorption models were investigated, and the process was fitted with the Langmuir model. Thermodynamic parameters showed that the process was spontaneous (ΔG < 0), endothermic (ΔH > 0) and the adsorption mechanism was following the physisorption mechanism at room temperature.

Evaluation of heavy metals contamination and pollution indices levels in surface sediments of the Bizerte coastal line, Tunisia.

Heavy metal concentrations in surface sediments collected from 17 stations samples in Bizerte coastal line were determined in order to evaluate the contamination status in the region. Heavy metal concentrations (mg/kg) of Bizerte coast line followed the decreasing trend of Fe > Pb > Zn > Mn > Cu > Cr > Ni > Co > Cd. The pollution degree of the surface sediment collected from 17 samples station in Bizerte coast line by heavy metals was evaluated on the basis of pollution indices (EF, Igeo, CF, PLI and CD). Results of Igeo, EF, CF, PLI and DC demonstrated that pollution levels of Pb and Cd were moderate, which should require more attentiveness as main pollution factors. However, no pollution was found for Zn, Cu, Ni, Cr, Co and Mn. Hierarchical cluster analysis was used to identify the influence of anthropogenic activities on the surface sediment.

Effect of Fuel Preheating on Engine Characteristics of Waste Animal Fat-Oil Biodiesel in Compression Ignition Engine.

The present study aims at understanding the effects of fuel preheating on engine characteristics of waste animal fat-oil (WAF-O) biodiesel in a single-cylinder CI engine, with the preheating technique proposed as an effective means for enhancing the fuel properties. To understand the effects of the preheated fuel, the WAF-O biodiesel was preheated at 60, 80, 100 and 120 °C and tested along with neat diesel and unheated WAF-O biodiesel. For this purpose, biodiesel was produced from different animal wastes by means of KOH-assisted ethanol-based transesterification, reporting its maximum yield as 96.37 ± 1.8%, with significant distribution of unsaturated oleic acid, saturated palmitic acid and stearic acid. Upon evaluating its fuel characteristics as per ASTM D6751 standards, a rise in preheating temperature by 1 °C reduced the density and kinematic viscosity of WAF-O biodiesel by 0.383 kg/m3 and 0.025 mm2/s, respectively, and was explained by the weakening of intermolecular forces between its fatty acid ester molecules. Preheated samples reported superior combustion characteristics by exhibiting increased in-cylinder pressure (2.24%, on average) and heat release rates in addition to their shortened ignition delay (1−4 °CA). Furthermore, preheating of WAF-O biodiesel reduced its specific fuel consumption and increased its brake thermal efficiency by 7.86% (on average) and 9.23% (on average), respectively. However, higher preheating temperatures (>120 °C) resulted in increased fuel consumption owing to its varied flow characteristics. In addition to the changes in combustion characteristics, preheating WAF-O bio-diesel also resulted in reduced carbon monoxide, nitrous oxide and hydrocarbon emission by 13.88%, 7.21% and 26.94%, respectively, and increased carbon dioxide emission by 7.58%. Summing up, the enhancements in overall engine characteristics of preheated samples were accounted for by their improvised fuel injection characteristics due to their reduced density and viscosity, which ensured for their effective combustion.

Evaluation of Wound Healing Activity (Excision Wound Model) of Ointment Prepared from Infusion Extract of Polyherbal Tea Bag Formulation in Diabetes-Induced Rats.

In the present investigation, Ichnocarpus frutescens, Ficus dalhousiae, Crateva magna, Alpinia galanga, and Swertia chirata plants were selected to formulate polyherbal tea bag. The infusion obtained from these polyherbal tea bags was used to formulate 5% and 10% ointment formulation to perform its wound healing activity. The excision wound model was used to assess the wound healing activity in diabetic as well nondiabetic rats. The mean percentage closure of wound area was calculated on the 3rd, 6th, 9th, 12th, 15th, 18th, and finally 21st day. The wound healing activity of formulation was found to be significantly compared with that of the reference standard and untreated groups. The percentages of closure of excision wound area on the 21st day in diabetic animals treated with ointment formulations (F1 and F2) were found to be 93.91 ± 1.65% and 99.12 ± 5.21% respectively, whereas the chloramphenicol sodium drug solution was found to be 99.81 ± 3.16%. The percentages of closure of excision wound area in nondiabetic animals treated with ointment formulations (F1 and F2) were found to be 96.81 ± 2.04% and 98.13 ± 1.14%, respectively, whereas the chloramphenicol sodium drug solution was found to be 99.15 ± 1.41% at 21st day. Therefore, from the above results, we have concluded that this polyherbal ointment can be used clinically for the treatment of diabetic and nondiabetic wounds.

Assessment of Antioxidative and Alpha-Amylase Potential of Polyherbal Extract.

The present study aims to prepare a polyherbal formulation (PHF) of Azadirachta indica (Neem), Aloe barbadensis (Aloe vera), Allium sativum (garlic), Acacia arabica (Babul), and Aegle marmelos (Bel) and evaluation of antidiabetic and antioxidant activity utilizing the in vitro model. Air-dried powder of 5 medicinal plants, which are divided into equal portions, and PHF, is prepared by the soxhlet technique using polar and nonpolar solvents. The PHF is screened for the phytochemical screening, and then the antidiabetic activity is determined by alpha-amylase inhibition. The extracts thus obtained are also subjected to the inhibition assay by the use of (DNS) dinitro salicylic acid. The antioxidant activity was determined by the DPPH radical scavenging assay, H2O2 scavenging assay, and TBARS assay. In in vitro study, the result revealed polyherbal formulation in which hot water extract has the topmost inhibitory effect on alpha-amylase activity, ranging from 20.4% to 79.5% with an IC50 value of 48.98 ± 0.31 µg/ml. This extract clearly showed the effective lowering of postprandial hypertriglyceridemia (PPHG). In the antioxidant activity carried out by using the (DPPH) radical scavenging assay, the highest result was obtained by the concentration of 250 µg/ml, which was around 77.2 ± 0.05 with statistical significance compared with control (a: p < 0.01; b: p < 0.001), while in the GTA method, the highest result was obtained by the concentration of 250 µg/ml, which was around 78.2 ± 0.05, and in the case of the TBARS assay, the concentration of 250 µg/ml gave around 76.2 ± 0.03 anti-oxidant value. In conclusion, the study shows that polyherbal formulation has superior antidiabetic activity and antioxidant properties.

Clinical Application of Augmented Reality in Computerized Skull Base Surgery.

Cranial base tactics comprise the regulation of tiny and complicated structures in the domains of otology, rhinology, neurosurgery, and maxillofacial medical procedure. Basic nerves and veins are in the nearness of these buildings. Increased the truth is a coming innovation that may reform the cerebral basis approach by supplying vital physical and navigational facts brought together in a solitary presentation. In any case, the awareness and acknowledgment of prospective results of expanding reality frameworks in the cerebral base region are really poor. This article targets examining the handiness of expanded reality frameworks in cranial foundation medical procedures and emphasizes the obstacles that present innovation encounters and their prospective adjustments. A specialized perspective on distinct strategies used being produced of an improved realty framework is furthermore offered. The newest item offers an expansion in interest in expanded reality frameworks that may motivate more secure and practical procedures. In any case, a couple of concerns have to be cared to before that can be for the vast part fused into normal practice.

ZnS Quantum Dots Decorated on One-Dimensional Scaffold of MWCNT/PANI Conducting Nanocomposite as an Anode for Enzymatic Biofuel Cell.

This study aims to design a new nanocomposite as a supporting material for wiring the enzyme to develop a bioanode in the enzymatic biofuel cell (EBFC). In this work, polyaniline-based nanocomposite was synthesized by in situ polymerization of aniline monomer. The zeta potential study of the nanofillers was carried out, which reveals the interaction between the nanofillers. The synthesized nanocomposite (MWCNT/ZnS/AgNWs/PANI) was characterized by analytical techniques, such as Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction spectroscopy (XRD). Furthermore, the surface morphology and the in-depth information of the synthesized nanocomposite were displayed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. In addition, the as-synthesized nanocomposite and the designed bioanode underwent the electrochemical assessment using different electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV) for evaluating the electrochemical behavior of the fabricated anodes. The electrochemically regulated bioanode (MWCNT/ZnS/AgNWs/PANI/Frt/GOx) obtained an open-circuit voltage of 0.55 V and produced a maximal current density of 7.6 mA cm-2 at a glucose concentration of 50 mM prepared in phosphate buffer solution (PBS) (pH 7.0) as a supporting electrolyte at a scan rate of 100 mV s-1.

Developmental exposure to the A6-pesticide causes changes in tyrosine hydroxylase gene expression, neurochemistry, and locomotors behavior in larval zebrafish.

Purpose: In recent years, the increase in the biopesticides synthesis for alternative agricultural uses has required their impacts study. Among these compounds, several of them are known to exert endocrinedisrupting (EDs) effects causing deregulation of physiological functions affecting cell signaling pathways involved in neural cell differentiation leading to developmental neurotoxicity. The objective of our study was to determine the impact of the biopesticide A6 structurally related to estrogenic EDs on zebrafish larvae, to define its toxicity, the mechanisms responsible, and to monitor the locomotors activity at nanomolar concentrations (0. 0.5, 5 and 50 nM).Materials and methods: Using imaging analysis tools, immunohistochemistry, quantitative PCR, and an automated behavior recording system (Zebrabox) we were able to assess these effects.Results: We have shown through its blue fluorescence properties that it accumulates in different parts of the body such as the intestine, adipose tissue, muscles, yolk sac and head. A6 also disrupted swimming behavior by affecting the expression of tyrosine hydroxylase (TH) in dopaminergic neurons.Conclusions: In conclusion, our study provided a mechanistic understanding of the A6 neurotoxic effect which could be the result of its binding to the estrogen receptor.

Diuron environmental levels effects on marine nematodes: Assessment of ecological indices, taxonomic diversity, and functional traits.

Coastal marine systems are the most sensitive zones to emerging pollutants. The present study aims to investigate the effect of Diuron on the meiofaunal assemblages, collected from the Bizerte channel (Tunisia). Microcosm experiments were set up using four increasing Diuron concentrations [D1 (10 ng g-1 dry weight (DW)), D2 (50 ng g-1 DW), D3 (250 ng g-1 DW) and (1250 ng g-1 DW)] compared to non-contaminated sediments (controls) and all plots were incubated for 30 days. Our results show that Diuron-supplemented sediments provoked the significant decrease of meiofaunal abundance as well as a change in nematodes' diversity and structure composition. All univariate indices, as well as the cumulative k-dominance, were lower in the Diuron than the control plot. Additionally, the ordination of treatments according to the two-dimensional nMDS plots analysis showed a clear structural separation of the Diuron treated replicates from the controls based on the functional groups lists. These current data emphasize the utility of the use of biological traits in the detection of disturbances in the aquatic biotope.

Protective effect of the Spirulina platensis against toxicity induced by Diuron exposure in Mytilus galloprovincialis.

Diuron herbicide is widely used for weeds control in many kinds of cultivations. It reaches the waterbodies through various fate routes and can adversely threaten non-target organism. The current study was carried out to evaluate the antioxidant activity of Spirulina as feed additive against the toxicity of Diuron concentrations (40 and 80 µg/L) on the edible mollusk Mytilus galloprovincialis during seven days of exposure. Oxidative stress biomarkers were applied on mussel gills and digestive gland, investigating changes in enzymes activities such as catalase (CAT), Glutathione-S-transferase (GST) and Acetylcholinesterase (AChE) and the Malondialdehyde level (MDA). The obtained results show that diuron altered oxidative stress biomarkers in both organs, gills and digestive gland. Performed principle component analysis (PCA) highlighted relationship between biomarkers involved in functional response. Spirulina platensis supplemented diet (1 mg/L), completely ameliorated diuron-induced oxidative stress in mussel tissues. Thus, Spirulina seems to be a promising microalgae and eco-friendly tool helping the health recovery of aquatic animals subjected to environmental stressors.

This study provided recent and new data on the impact of Diuron in marine bivalve and the protective effect of Spirulina against Diuron-induced oxidative stress. The results of our study suggest that the antioxidant potential of Spirulina should be strongly candidate for the phytoremediation of Diuron-aquatic contaminated.

Silver nanoparticles' impact on the gene expression of the cytosolic adaptor MyD-88 and the interferon regulatory factor IRF in the gills and digestive gland of mytilus galloprovincialis.

Silver nanoparticles (AgNPs) have been reported as stressors for the bivalves' immune system at different regulatory levels, impacting the detection step and receptors, and other mediators, as well as effector molecules. However, studies on how AgNPs impact the transmission of signals from receptors and whether they have an effect on mediators and transcription factors are still scarce. This study aims to investigate the effect of 12 hours of in vivo exposure to 100 µg/L of AgNPs on the gene expression of the cytosolic adaptor Myeloid, the differentiation protein 88 (MgMyD88-b), and the interferon regulatory factor (Me4-IRF) in the gills and digestive gland of Mytilus galloprovincialis, before and after blocking two major uptake pathways of nanoparticles (clathrin- and caveolae-mediated endocytosis). The results illustrate a tissue-specific gene expression of the MgMyD88-b and the Me4-IRF in the gills and digestive gland of M. galloprovincialis. In the gills, AgNPs did not significantly impact the expression of the two genes. However, blocking the caveolae-mediated endocytosis decreased the expression of Me4-IRF. However, inhibition of clathrin-mediated endocytosis in the digestive gland recorded a significant decrease in the expression of MgMyD88-b. Overall, the inhibition of the AgNPs' uptake routes have highlighted their potential interference with the immune response through the studied mediators' genes, which need to be studied further in future investigations.

Effect of Plasmonic Gold Nanoprisms on Biofilm Formation and Heat Shock Proteins Expression in Human Pathogenic Bacteria.

Gold nanoparticles have gained interest in biomedical sciences in the areas of nano-diagnostics, bio-labeling, drug delivery, and bacterial infection. In this study, we examined, for the first time, the antibacterial and antibiofilm properties of plasmonic gold nanoprisms against human pathogenic bacteria using MIC and crystal violet. In addition, the expression level of GroEL/GroES heat shock proteins was also investigated by western blot. Gold nanoparticles were characterized by TEM and EDX, which showed equilateral triangular prisms with an average edge length of 150 nm. Antibacterial activity testing showed a great effect of AuNPs against pathogenic bacteria with MICs values ranging from 50 µg/mL to 100 µg/mL. Nanoparticles demonstrated strong biofilm inhibition action with a percentage of inhibition ranging from 40.44 to 82.43%. Western blot analysis revealed that GroEL was an AuNPs-inducible protein with an increase of up to 66.04%, but GroES was down-regulated with a reduction of up to 46.81%. Accordingly, plasmonic gold nanoprisms, could be a good candidate for antibiotics substitution in order to treat bacterial infections.

Bergenia ciliate-Mediated Mixed-Phase Synthesis and Characterization of Silver-Copper Oxide Nanocomposite for Environmental and Biological Applications.

Bergenia ciliate (B. ciliate) leaf extract was used as a reducing and stabilizing agent for the synthesis of silver-copper oxide nanocomposite (Ag-CuO NC). Scanning and transmission electron microscopies (SEM and TEM) were used to examine the structural morphology, and the average particle size was determined to be 47.65 nm. The phase confirmation and crystalline structure were examined through the X-ray diffraction (XRD) technique, where cubic and monoclinic geometries were assigned to Ag and CuO. The energy dispersive X-ray (EDX), Fourier transform infrared (FTIR) and ultra-violet and visible (UV-Visible) spectroscopies were operated to analyse the elemental composition, functional groups and light absorption phenomena of the Ag-CuO NC. Under the full light spectrum, the photodegradation of Rhodamine 6G was recorded, and 99.42 percent of the dye degraded in 80 min. The Agar well diffusion method was followed to perform antibacterial activity against selected pathogens, and the activity was found to increase with increasing concentration of Ag-CuO NC. The ABTS free radical scavenging activity suggests that the activity of Ag-CuO NC is higher than ascorbic acid.

In-Vitro and In-Vivo Tolerance and Therapeutic Investigations of Phyto-Fabricated Iron Oxide Nanoparticles against Selected Pathogens.

The Paeonia emodi (P. emodi)-mediated iron oxide nanoparticles (Fe2O3 NPs) were screened for in-vitro and in-vivo antibacterial activity against the Staphylococcus aureus (S. aureus) (ATCC #: 6538) and Escherichia coli (E. coli) (ATCC #:15224). The synthesized Fe2O3 NPs were characterized via nitrogen adsorption-desorption process, X-ray diffractometer (XRD), transmission and scanning electron microscopies (TEM and SEM), energy dispersive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopies. The SBET was found to be 94.65 m2/g with pore size of 2.99 nm, whereas the average crystallite and particles size are 23 and 27.64 nm, respectively. The 4 µg/mL is the MIC that inhibits the growth of E. coli, whereas those for S. aureus are below the detection limit (<1.76 µg/mL). The tolerance limit of the mice model was inspected by injecting different concentration of Fe2O3 NPs and bacteria suspensions. The 14 ppm suspension was the tolerated dose and the concentration above were proved lethal. The most severe infection was induced in mice with injection of 3 × 107 CFUs of both bacteria, while the inoculation of higher concentrations of bacterial suspensions resulted in the mice's death. The histopathological and hematological studies reveals that the no/negligible infection was found in the mice exposed to the simultaneous inoculation of Fe2O3 NPs (14 ppm) and bacterial suspensions (3 × 107 CFUs).

Does the photocatalytic activity of nanoparticles protect the marine mussel Mytilus galloprovincialis from polycyclic aromatic hydrocarbon toxicity?

In the present study, five NPs (containing ZnO, Au-ZnO, Cu-ZnO, TiO2, and Au-TiO2) were characterized using dynamic light scattering and transmission electron microscopy, in order to observe their behavior under environmental change. The applicability of NPs for degradation of three polycyclic aromatic hydrocarbons (PAHs), including benzo(a)pyrene, fluoranthene, and benzanthracene, using UV irradiation showed the high photocatalytic efficiency of doped NPs for the removal of the study pollutants. To predict the environmental impact and interaction between NPs and PAHs on marine organisms, Mytilus galloprovincialis mussels were exposed to concentrations of each chemical (50 and 100 µg/L) for 14 days. The mussel's response was determined using the oxidative stress biomarker approach. Measured biomarkers in the mussel's digestive gland showed possible oxidative mechanisms in a concentration-dependent manner occurring after exposure to PAHs and NPs separately. Overall, this finding provides an interesting combination to remove PAHs in water, and the incorporation of chemical element into the crystallographic structure of NPs and the combination of two different NPs to form a binary hybrid NPs are promising materials.

Au-TiO2 nanoparticles exposure induced oxidative stress and neurotoxicity in rat.

CONTEXT: The Au-TiO2NPs have a wide range of applications and can easily enter the cells. Due to their properties, they can cause toxicity. OBJECTIVE: It was aimed to test the toxic effects of Au-TiO2 NPs in the brain, heart, kidney and liver of rats in this work. MATERIALS AND METHODS: All used rats in this work were treated using diverse concentrations (doses) of NPs (100 and 200 mg/kg bw) for 21 days. SOD, CAT, AChE activities and MDA, H2O2, NO contents were evaluated in different organs. RESULTS: The Au-TiO2 NPs exposure induced biochemical changes in different organs of rats in view of oxidative stress and neurotoxicity by the alteration of the activity of the enzyme of neurotransmitter (AChE activity). CONCLUSION: The Au-TiO2 NPs have the potential to interact with rat's biochemical status and cause undesirable effects. One of those damaging effects was oxidative stress and neurotoxicity. CLINICAL SIGNIFICANCE: The study signifies the impact of usage of Au-TiO2 NPs in the medical field for further exploration.

Metal accumulation, biochemical and behavioral responses on the Mediterranean clams Ruditapes decussatus exposed to two photocatalyst nanocomposites (TiO2 NPs and AuTiO2NPs).

Nanoparticle decoration with noble metal represents a promising alternative to improve their photocatalytic and photovoltaic properties. However, toxicity can be influenced by such modification, as the bioavailability of these substances may be influenced. To understand how decoration influences the NP impacts in marine ecosystems, we exposed suspension-feeding clams, Ruditapes decussatus, to two photocatalyst nanocomposites, TiO2 NPs and AuTiO2 NPs, over 2 concentrations, 50 µg L-1and 100 µg L-1, in a laboratory experiment. Accumulation of Au and Ti in gills and digestive gland was noted in clams after exposure to TiO2 NPs and AuTiO2 NPs using inductively coupled plasma optic emission spectroscopy (ICP-OES). TiO2 and AuTiO2 NPs alter the behavior of the clams Ruditapes decussatus by reducing filtration and respiration rates. Furthermore, the highest concentration of TiO2NPs induces an overproduction of H2O2 in gills and digestive gland and NO production only in gills. Superoxide dismutase (SOD), Catalase (CAT), Glutathione-S-transferase (GST) and acetylcholinesterase (AChE) activities were induced in gills and digestives gland in concentration and nanocomposite type dependent manner. Decorated form presented higher Malondialdehyde (MDA) levels in gills and digestive gland than the undecorated form, suggesting different mechanisms of action that may be mediated through oxidative stress. In conclusion, the considered parameters could represent reliable biomarkers for the assessment of NP toxicity on R. decussatus as biological biomonitoring model. In addition, based on the obtained results, nanoparticle decoration influences the toxicity of metal nanoparticles in marine organism.

Triangular gold nanoparticles modify shell characteristics and increase antioxidant enzyme activities in the clam Ruditapes decussatus.

CONTEXT: Nanoparticles may cause adverse environmental effects but there is limited information on their interactions with marine organisms. OBJECTIVE: Our aim was to examine the effects of triangular gold nanoparticles (Tr-Au NPs) on the clam, Ruditapes decussatus. MATERIALS AND METHODS: Clams were exposed to Tr-Au1 = 5 µg/L and Tr-Au2 = 10 µg/L for 2 and 7 days. Effects on shell structure were investigated. Superoxide dismutase (SOD), catalase (CAT), glutathione transferase (GST) activities, protein carbonyl levels and malondialdehyde content were used to assess biochemical status. RESULTS: Transmission electron microscopy (TEM) and electron dispersive X-ray microanalysis (EDX) showed that Tr-Au NPs modified shell structure and morphology. Tr-Au NPs size increased forming aggregate particles. Tr-Au NPs increased SOD, CAT and GST activities in gill and digestive gland in a concentration- and time-dependent manner indicating defence against oxidative stress. Enhanced lipid peroxidation and protein carbonyl levels confirmed oxidative stress. CONCLUSION: Tr-Au NPs cause oxidative stress and affect shell structure of clams. These findings may have relevance to other marine species.