Role of endocytotic uptake routes in impacting the ROS-related toxicity of silver nanoparticles to Mytilus galloprovincialis: A redox proteomic investigation

Dissolving microneedle synergistic rocaglamide-loaded liposome to regulate abnormal neutrophils for anti-psoriasis

Psoriasis seriously affects the physical and mental health of patients. Rocaglamide (RocA), derived from Aglaia odorata, exhibits potent pharmacological activities. Although its efficacy in psoriasis is unclear, RocA could be a promising therapeutic drug. In this work, RocA showed a good therapeutic effect in psoriasis mice induced by imiquimod, and subsequent TMT-based proteomics analysis verified that the effect of RocA was related to IL-1 family cytokines. Furthermore, a RocA-loaded liposome (RocA@Lipo) was developed and encapsulated in the tip-layer of microneedles (MNs) to construct a MN-based nano drug delivery system (RocA@Lipo-MNs). In vitro HaCaT cell assays demonstrated that RocA@Lipo enhanced the cytotoxicity and cell uptake of RocA. In vivo, RocA@Lipo-MNs outperformed other RocA formulations in inhibiting psoriasis epidermal thickening and spleen enlargement. Immunohistochemical, ELISA, western blot, and PCR experiments further proved that RocA@Lipo-MNs could inhibit neutrophil infiltration in the skin, revealing that the anti-psoriasis mechanism of RocA was deemed to inhibit the binding of IL-1α and IL-1R1 to regulate the activation of MAPK and NF-κB pathways. Thus, the production of inflammatory factors and neutrophil chemokines was reduced, which was associated with apoptosis inhibition. Importantly, RocA@Lipo-MNs significantly improved the transdermal properties of RocA and exhibited good skin and blood safety. This work provides new ideas for the clinical application of RocA and the treatment options for psoriasis.

Mechanisms of ingested polystyrene micro-nanoplastics (MNPs) uptake and translocation in an in vitro tri-culture small intestinal epithelium

Micro and nanoplastics (MNPs) are now ubiquitous contaminants of food and water. Many cellular and animal studies have shown that ingested MNPs can breach the intestinal barrier to reach the circulation. To date however, the cellular mechanisms involved in intestinal absorption of MNPs have not been investigated with physiologically relevant models, and thus remain unknown. We employed in vitro simulated digestion, a tri-culture small intestinal epithelium model, and a panel of inhibitors to assess the contributions of the possible mechanisms to absorption of 26 nm carboxylated polystyrene (PS26C) MNPs. Inhibition of ATP synthesis reduced translocation by only 35 %, suggesting uptake by both active endocytic pathways and passive diffusion. Translocation was also decreased by inhibition of dynamin and clathrin, suggesting involvement of clathrin mediated endocytosis (CME) and fast endophilin-mediated endocytosis (FEME). Inhibition of actin polymerization also significantly reduced translocation, suggesting involvement of macropinocytosis or phagocytosis. However, inhibition of the Na+-H+ exchanger had no effect on translocation, thus ruling out macropinocytosis. Together these results suggest uptake by passive diffusion as well as by active phagocytosis, CME, and FEME pathways. Further studies are needed to assess uptake mechanisms for other environmentally relevant MNPs as a function of polymer, surface chemistry, and size.

Ecotoxicity and trophic transfer of metallic nanomaterials in aquatic ecosystems

Metallic nanomaterials (MNMs) possess unique properties that have led to their widespread application in fields such as electronics and medicine. However, concerns about their interactions with environmental factors and potential toxicity to aquatic life have emerged. There is growing evidence suggesting MNMs can have detrimental effects on aquatic ecosystems, and are potential for bioaccumulation and biomagnification in the food chain, posing risks to higher trophic levels and potentially humans. While many studies have focused on the general ecotoxicity of MNMs, fewer have delved into their trophic transfer within aquatic food chains. This review highlights the ecotoxicological effects of MNMs on aquatic systems via waterborne exposure or dietary exposure, emphasizing their accumulation and transformation across the food web. Biomagnification factor (BMF), the ratio of the contaminant concentration in predator to that in prey, was used to evaluate the biomagnification due to the complex nature of aquatic food chains. However, most current studies have BMF values of less than 1 indicating no biomagnification. Factors influencing MNM toxicity in aquatic environments include nanomaterial properties, ion variations, light, dissolved oxygen, and pH. The multifaceted interactions of these variables with MNM toxicity remain to be fully elucidated. We conclude with recommendations for future research directions to mitigate the adverse effects of MNMs in aquatic ecosystems and advocate for a cautious approach to the production and application of MNMs.

Effects of rare earth element samarium doped zinc oxide nanoparticles on Mytilus galloprovincialis (Lamarck, 1819): Filtration rates and histopathology

BACKGROUND

Doping was reported to improve the photo catalytic performance, antioxidant, antibacterial and other biological properties of nanoparticles. While, improving the nanoparticle properties, doping could change toxicity profile to living organism. Hence, the aim of this work was to assess the effects of samarium doped zinc oxide nanoparticles (Sm doped ZnO NPs) on the edible mussel Mytilus galloprovincialis.

METHODS

Sm doped ZnO nanoparticles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) techniques. 156 mussels were exposed during 7 days to a low, intermediate and high concentration of Sm doped ZnO NPs (0.5, 1 and 1.5 mg/L, respectively). The filtration rates were assessed after 1 and 2 h. Histopathological alterations were determined in gills, digestive glands and gonads using a quantitative analysis.

RESULTS

The filtration rates decreased in all individuals exposed to Sm doped ZnO NPs, a significant decrease was noted with the low and intermediate concentration (0.5 and 1 mg/L) of Sm doped ZnO NPs after 1 and 2 h, respectively. The histopathological index (Ih) estimated for gills, digestive glands and gonads showed differences depending on the organ and the nanoparticle concentration. The highest Ih were reported for digestive glands and female gonads exposed to the intermediate concentration (1 mg/L) of Sm doped ZnO NPs. As for gills and male gonads, the highest Ih were noted with the high concentration (1.5 mg/L) of Sm doped ZnO NPs.

CONCLUSION

Results from this study revealed the toxicity of Sm doped ZnO NPs in Mytilus galloprovincialis gills, digestive glands and gonads. The toxicity induced by this nanoparticle varies depending on the organ and the concentration.

Ecotoxicological effects of silver nanoparticles in marine mussels

As the production of silver nanoparticles (AgNPs) is becoming more prevalent, it is becoming increasingly necessary to understand the toxicological effects they can have on different ecosystems. In the marine bioindicator species M. galloprovincialis Lam we predicted toxicity and bioaccumulation of 5 nm alkane-coated and 50 nm uncoated silver nanoparticles (AgNPs) along with silver nitrate as a function of the actual dose level. We generated a time persistence model of silver in seawater and used the Area Under the Curve (AUC) as independent variable in the hazard assessment. This approach allowed us to evaluate unbiased ecotoxicological endpoints for acute (survival) and chronic toxicity (byssal adhesion). Logistic regression analysis rendered an overall LC50_96h values of 0.81 ± 0.07 mg h L^-1 irrespectively of the silver form. By contrast, for byssal adhesion regression analysis revealed a much higher toxicological potential of silver nitrate vs AgNPs with EC50_24h values respectively of 0.0024 ± 0.0009 vs 0.053 ± 0.016 and 0.063 (no computable error for 50 nm AgNP) mg h L^-1, undoubtedly confirming a prevalence of ionic silver effects over AgNPs. Bioaccumulation was more efficient for silver nitrate >5 nm AgNP >50 nm AgNP reflecting a parallel with the preferential uptake route / target organ. Finally, we derived Risk Quotient (RQs) for acute and chronic effects of nanosilver in shellfish and showed that the RQs are far from the Level of Concern (LoC) at current estimated environmental concentrations (EECs). This information can ultimately help researchers, policy makers, and industry professionals decide how to safely regulate and/or dispose of AgNPs.

Proteomic evaluation of nanotoxicity in aquatic organisms: A review

The alteration of organisms protein functions by engineered nanoparticles (ENPs) is dependent on the complex interplay between their inherent physicochemical properties (e.g., size, surface coating, shape) and environmental conditions (e.g., pH, organic matter). To date, there is increasing interest on the use of 'omics' approaches, such as proteomics, genomics, and others, to study ENPs-biomolecules interactions in aquatic organisms. However, although proteomics has recently been applied to investigate effects of ENPs and associated mechanisms in aquatic organisms, its use remain limited. Herein, proteomics techniques widely applied to investigate ENPs-protein interactions in aquatic organisms are reviewed. Data demonstrates that 2DE and mass spectrometry and/or their combination, thereof, are the most suitable techniques to elucidate ENPs-protein interactions. Furthermore, current status on ENPs and protein interactions, and possible mechanisms of nanotoxicity with emphasis on those that exert influence at protein expression levels, and key influencing factors on ENPs-proteins interactions are outlined. Most reported studies were done using synthetic media and essay protocols and had wide variability (not standardized); this may consequently limit data application in actual environmental systems. Therefore, there is a need for studies using realistic environmental concentrations of ENPs, and actual environmental matrixes (e.g., surface water) to aid better model development of ENPs-proteins interactions in aquatic systems.

Hemocytes of bivalve mollusks as cellular models in toxicological studies of metals and metal-based nanomaterials

Understanding the impacts of environmental pollutants on immune systems is indispensable in ecological and health risk assessments due to the significance of normal immunological functions in all living organisms. Bivalves as sentinel organisms with vital ecological importance are widely distributed in aquatic environments and their innate immune systems are the sensitive targets of environmental pollutants. As the central component of innate immunity, bivalve hemocytes are endowed with specialized endolysosomal systems for particle internalization and metal detoxification. These intrinsic biological features make them a unique cellular model for metal- and nano-immunotoxicology research. In this review, we firstly provided a general overview of bivalve's innate immunity and the classification and immune functions of hemocytes. We then summarized the recent progress on the interactions of metals and nanoparticles with bivalve hemocytes, with emphasis on the involvement of hemocytes in metal regulation and detoxification, the interactions of hemocytes and nanoparticles at eco/bio-nano interface and hemocyte-mediated immune responses to the exposure of metals and nanoparticles. Finally, we proposed the key knowledge gaps and future research priorities in deciphering the fundamental biological processes of the interactions of environmental pollutants with the innate immune system of bivalves as well as in developing bivalve hemocytes into a promising cellular model for nano-immuno-safety assessment.

Comparative toxicity of silver nanoparticles and silver nitrate in freshwater fish Oreochromis mossambicus: A multi-biomarker approach

Silver nanoparticles (AgNPs) in the aquatic environment affect ecological repercussions and have fatal impacts on aquatic animals. The current study examined and correlated the toxicity of silver nitrate (AgNO₃) and silver nanoparticles (AgNPs) to the Mozambique tilapia, Oreochromis mossambicus. The comparative toxicity studies were done by exposing O. mossambicus to various doses of AgNO₃ and AgNPs (0, 25, 50, 75, and 100 μg/L) over a 7-day subacute exposure period. AAS analysis was used to detect Ag accumulation, while the histological examination established gill tissue damage. Oxidative stress affects lipid peroxidation (LPO) and protein carbonyl activity (PCA) in the gill tissue. Antioxidant parameters such as glutathione-S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase activity (CAT), and non-enzymatic antioxidants such as metallothionein (MT) and reduced glutathione. The serum in the blood was used to determine non-specific immunological characteristics such as lysozyme (LYZ), myeloperoxidase (MPO), and respiratory burst activity (RBA). The neurotoxic impact of acetylcholine esterase activity (AChE) was investigated in brain tissues. The findings demonstrated that larger concentrations of AgNO₃ than AgNPs improved enzymatic antioxidant activities in the gill tissue. Histological examination of fish gills demonstrated that both AgNPs and AgNO₃ induced telangiectasia and epithelial cell hyperplasia. By increasing the concentration of AgNPs and AgNO₃, the present research demonstrated that silver accumulation leads to inefficient oxidative stress and altered enzymatic and non-enzymatic parameters, leading to cellular damage.

In-Gel Assay to Evaluate Antioxidant Enzyme Response to Silver Nitrate and Silver Nanoparticles in Marine Bivalve Tissues

Silver is back in vogue today as this metal is used in the form of nanomaterials in numerous commercial products. We have developed in-gel electrophoretic techniques to measure the activity of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX), and used the same techniques in combination with HSP70 Western blot analysis to evaluate the effects of nanomolar amounts of silver nitrate and 5 nm alkane-coated silver nanoparticles in tissues of the marine bivalve Mytilus galloprovincialis (Lam.) exposed for 28 days in mesocosms. Our results showed a negligible effect for nanosilver exposure and dose-dependent effects for the nitrate form.

Highly Sensitive and Specific Responses of Oyster Hemocytes to Copper Exposure: Single-Cell Transcriptomic Analysis of Different Cell Populations

Oyster hemocytes are the primary vehicles transporting and detoxifying metals and are regarded as important cells for the occurrence of colored oysters due to copper (Cu) contamination. However, its heterogeneous responses under Cu exposure have not been studied. Single-cell transcriptome profiling (scRNA-seq) provides high-resolution visual insights into tissue dynamics and environmental responses. Here, we used scRNA-seq to study the responses of different cell populations of hemocytes under Cu exposure in an estuarine oyster Crassostrea hongkongensis. The 1900 population-specific Cu-responsive genes were identified in 12 clusters of hemocytes, which provided a more sensitive technique for examining Cu exposure. The granulocyte, semigranulocyte, and hyalinocyte had specific responses, while the granulocyte was the most important responsive cell type and displayed heterogeneity responses of its two subtypes. In one subtype, Cu was transported with metal transporters and chelated with Cu chaperons in the cytoplasm. Excess Cu disturbed oxidative phosphorylation and induced reactive oxygen species production. However, in the other subtype, endocytosis was mainly responsible for Cu internalization, which was sequestered in membrane-bound granules. Collectively, our results provided the first mRNA expression profile of hemocytes in oysters and revealed the heterogeneity responses under Cu exposure.

Silver Nanoparticles Modulate the Epithelial-to-Mesenchymal Transition in Estrogen-Dependent Breast Cancer Cells In Vitro

Silver nanoparticles (AgNPs) are frequently detected in many convenience goods, such as cosmetics, that are applied directly to the skin. AgNPs accumulated in cells can modulate a wide range of molecular pathways, causing direct changes in cells. The aim of this study is to assess the capability of AgNPs to modulate the metastasis of breast cancer cells through the induction of epithelial-to-mesenchymal transition (EMT). The effect of the AgNPs on MCF-7 cells was investigated via the sulforhodamine B method, the wound healing test, generation of reactive oxygen species (ROS), the standard cytofluorimetric method of measuring the cell cycle, and the expression of EMT marker proteins and the MTA3 protein via Western blot. To fulfill the results, calcium flux and HDAC activity were measured. Additionally, mitochondrial membrane potential was measured to assess the direct impact of AgNPs on mitochondria. The results indicated that the MCF-7 cells are resistant to the cytotoxic effect of AgNPs and have higher mobility than the control cells. Treatment with AgNPs induced a generation of ROS; however, it did not affect the cell cycle but modulated the expression of EMT marker proteins and the MTA3 protein. Mitochondrial membrane potential and calcium flux were not altered; however, the AgNPs did modulate the total HDAC activity. The presented data support our hypothesis that AgNPs modulate the metastasis of MCF-7 cells through the EMT pathway. These results suggest that AgNPs, by inducing reactive oxygen species generation, alter the metabolism of breast cancer cells and trigger several pathways related to metastasis.

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.

Transport of environmental natural organic matter coated silver nanoparticle across cell membrane based on membrane etching treatment and inhibitors

Environmental natural organic matters (NOMs) have great effects on the physicochemical properties of engineering nanoparticles, which may impact the transport of nanoparticles across plasma membrane and the cytotoxicity. Therefore, the kinetics, uptake pathway and mass of transporting into A549 cell membrane of silver nanoparticles (AgNPs) coated with citric acid (CA), tartaric acid (TA) and fulvic acid (FA) were investigated, respectively. CA, FA and TA enhanced the colloidal stability of AgNPs in culture medium and have greatly changed the surface plasmon resonance spectrum of AgNPs due to the absorption of CA, FA and TA on surface of AgNPs. Internalizing model showed that velocity of CA-, TA- and FA-nAg transporting into A549 cell were 5.82-, 1.69- and 0.29-fold higher than those of the control group, respectively. Intracellular mass of Ag was dependent on mass of AgNPs delivered to cell from suspension, which obeyed Logistic model and was affected by NOMs that CA- and TA-nAg showed a large promotion on intracellular mass of Ag. The lipid raft/caveolae-mediated endocytosis (LME) of A549 cell uptake of AgNPs were susceptible to CA, TA and FA that uptake of CA-, TA- and FA-nAg showed lower degree of dependent on LME than that of the control (uncoated AgNPs). Actin-involved uptake pathway and macropinocytosis would have less contribution to uptake of FA-nAg. Overall, transmembrane transport of NOMs-coated AgNPs differs greatly from that of the pristine AgNPs.

Can Proteomics Be Considered as a Valuable Tool to Assess the Toxicity of Nanoparticles in Marine Bivalves?

Exposure to nanoparticles (NPs) has been identified as a major concern for marine ecosystems. Because of their peculiar physico-chemical features, NPs are accumulated in marine organisms, which suffer a variety of adverse effects. In particular, bivalve mollusks represent a unique target for NPs, mainly because they are suspension-feeders with highly developed processes for cellular internalization of nano- and micrometric particles. Several studies have demonstrated that the uptake and the accumulation of NPs can induce sub-lethal effects towards marine bivalves. However, to understand the real risk of NP exposures the application of the so-called “omics” techniques (e.g., proteomics, genomics, metabolomics, lipidomics) has been suggested. In particular, proteomics has been used to study the effects of NPs and their mechanism(s) of action in marine bivalves, but to date its application is still limited. The present review aims at summarizing the state of the art concerning the application of proteomics as a tool to investigate the effects of nanoparticles on the proteome of marine bivalves, and to critically discuss the advantages and limitations of proteomics in this field of research. Relying on results obtained by studies that applied proteomics on bivalve tissues, proteomics application needs to be considered cautiously as a promising and valuable tool to shed light on toxicity and mechanism(s) of action of NPs. Although on one hand, the analysis of the current literature demonstrated undeniable strengths, potentiality and reliability of proteomics, on the other hand a number of limitations suggest that some gaps of knowledge need to be bridged, and methodological and technical improvements are necessary before proteomics can be readily and routinely applied to nanotoxicology studies.

Effects of nanosilver on hematologic, histologic and molecular parameters of rainbow trout (Oncorhynchus mykiss)

Efficient antibacterial and antifungal properties of silver nanoparticles (AgNPs) sparked its commercial application in several industrial and household products. Drastic increase of AgNPs production raised concerns over aquatic organisms' exposure. The toxic dose, mechanism of toxicity, physiological damages, gene expression alteration, hematological and blood parameter distortion by AgNP needs to be investigated to explore inevitable risk in aquatic animals. In this study, rainbow trout (Oncorhynchus mykiss) (122.4 ± 1.4 g, 23.8 ± 0.7 cm) were exposed to colloidal AgNPs (28.3 ± 12.6 um) to determine the lethal concentration (LC50)(8.9 mg/l). Sub-lethal concentrations (10 %LC50, 25 %LC50, plus LC50 value) impact on hematologic, histological and molecular responses were evaluated. Results showed sever damage to blood cells morphology, and hematologic parameters change including RBC, WBC, Hct and Hb in all AgNP-treated groups. Histological damage in gill and liver of exposed fish were observed. Significant up-regulating of HSP70 and P53 genes were detected in response to AgNPs, whereas, it was found that in comparison to HSP70 gene, P53 induction occurred in lower AgNPs concentrations and lower exposure time. These results indicate adversely effects of AgNPs exposure to aquatic environments.

Proteomic profiling reveals the differential toxic responses of gills of common carp exposed to nanosilver and silver nitrate

Although the toxic effects of silver nanoparticles (AgNPs) on fish gills have been reported, the underlying mechanism of toxicity remains unclear. The present study aimed to elucidate the mechanism of toxicity in the gills of common carp following exposure to AgNPs and silver nitrate (AgNO₃) using histopathology and proteomics. Histopathological findings revealed that both AgNPs and AgNO₃ caused telangiectasia and epithelial cell hyperplasia in fish gills; however, the pathological features and location of lesions caused by the two forms of silver were markedly different. Proteomics revealed that AgNPs and AgNO₃ induced 139 and 185 differential expression proteins (DEPs) in gills, respectively, and the two forms of silver induced only 42 shared proteins. AgNPs specifically induced 87 DEPs which mainly involved signaling mechanisms, cytoskeleton, and the arachidonic acid metabolism processes. AgNO₃ specifically induced 125 DEPs that were mainly clustered in the glutathione metabolism and protease processes. These results suggested that the toxic effects of AgNPs and AgNO₃ were dramatically different in terms of protein expression in fish gills, which may provide novel perspectives for understanding the toxicity mechanism of silver nanoparticles in fish gills.

Silver nanoparticles in dye effluent treatment: A review on synthesis, treatment methods, mechanisms, photocatalytic degradation, toxic effects and mitigation of toxicity

The current scenario of water resources shows the dominance of pollution caused by the draining of industrial effluents. The polluted waters have resulted in severe health and environmental hazards urging for a suitable alternative to resolve the implications. Various physical and chemical treatment steps currently in use for dye effluent treatment are more time consuming, cost-intensive, and less effective. Alternatively, nanoparticles due to their excellent surface properties and chemical reactivity have emerged as a better solution for dye removal and degradation. In this regard, the potential of silver nanoparticles in dye effluent treatment was greatly explored. Efforts were taken to unravel the kinetics and statistical optimization of the treatment conditions for the efficient removal of dyes. In addition, the role of silver nanocomposites has also experimented with colossal success. On the contrary, studies have also recognized the mechanisms of silver nanoparticle-mediated toxicity even at deficient concentrations and their deleterious biological effects when present in treated water. Hence, the fate of the silver nanoparticles released into the treated water and sludge, contaminating the soil, aquatic environment, and underground water is of significant concern. This review summarizes the current state of knowledge regarding the use of silver nanoparticles and silver-based nanocomposites in effluent treatment and comprehends the recent research on mitigation of silver nanoparticle-induced toxicity.

Changes in protein expression in mussels Mytilus galloprovincialis dietarily exposed to PVP/PEI coated silver nanoparticles at different seasons

Potential toxic effects of Ag NPs ingested through the food web and depending on the season have not been addressed in marine bivalves. This work aimed to assess differences in protein expression in the digestive gland of female mussels after dietary exposure to Ag NPs in autumn and spring. Mussels were fed daily with microalgae previously exposed for 24 h to 10 μg/L of PVP/PEI coated 5 nm Ag NPs. After 21 days, mussels significantly accumulated Ag in both seasons and Ag NPs were found within digestive gland cells and gills. Two-dimensional electrophoresis distinguished 104 differentially expressed protein spots in autumn and 142 in spring. Among them, chitinase like protein-3, partial and glyceraldehyde-3-phosphate dehydrogenase, that are involved in amino sugar and nucleotide sugar metabolism, carbon metabolism, glycolysis/gluconeogenesis and the biosynthesis of amino acids KEGG pathways, were overexpressed in autumn but underexpressed in spring. In autumn, pyruvate metabolism, citrate cycle, cysteine and methionine metabolism and glyoxylate and dicarboxylate metabolism were altered, while in spring, proteins related to the formation of phagosomes and hydrogen peroxide metabolism were differentially expressed. Overall, protein expression signatures depended on season and Ag NPs exposure, suggesting that season significantly influences responses of mussels to NP exposure.

A Comparative Assessment of Nanotoxicity Induced by Metal (Silver, Nickel) and Metal Oxide (Cobalt, Chromium) Nanoparticles in Labeo rohita

In the present in vivo study, we provide a comparison of toxicological consequences induced by four different types of spherical nanoparticles (NPs)—silver nanoparticles (AgNPs, 40 ± 6 nm), nickel (NiNPs, 43 ± 6 nm), cobalt oxide (Co₃O₄NPs, 60 ± 6 nm), and chromium oxide (Cr₃O₄NPs, 50 ± 5 nm)—on freshwater fish Labeo rohita. Fish were exposed to NPs (25 mg/L) for 21 days. We observed a NPs type-dependent toxicity in fish. An altered behavior showing signs of stress and a substantial reduction in total leukocyte count was noticed in all NP-treated groups. A low total erythrocyte count in all NP-treated fish except for Co₃O₄NPs was discerned while a low survival rate in the case of Cr₃O₄NP-treated fish was observed. A significant decrease in growth and hemoglobin were noticed in NiNP- and Cr₃O₄NP-treated fish. A considerable total protein elevation was detected in NiNP-, Co₃O₄NP-, and Cr₃O₄NP-treated groups. An upgrading in albumin level was witnessed in Co₃O₄NP- and Cr₃O₄NP-treated groups while a high level of globulin was noted in NiNP- and Co₃O₄NP-exposed groups. In all NP-treated groups, a depleted activity of antioxidative enzymes and pathological lesions in liver and kidney were noticed.