Effect of long‐term exposure of silver nanoparticles on growth indices, hematological and biochemical parameters and gonad histology of male goldfish ( Carassius auratus gibelio )

Changes in blood serum parameters in farmed rainbow trout (Oncorhynchus mykiss) during a piscine lactococcosis outbreak

The aquaculture sector plays a vital role in global food security, yet it grapples with significant challenges posed by infectious diseases. Piscine lactococcosis is one of the significant threats in rainbow trout aquaculture due to its potential to cause severe economic losses through mortalities, reduced growth rates, and increased susceptibility to other pathogens. It poses challenges in disease management strategies, impacting the sustainability and profitability of rainbow trout farming. The current study focuses on the variations in serum blood parameters of farmed rainbow trout Oncorhynchus mykiss during a lactococcosis outbreak caused by Lactococcus garvieae. Blood samples were collected for biochemical analysis, fish were examined for parasites and bacteria, and DNA from bacterial colonies was PCR-amplified and sequenced for identification. Overall, 13 biochemical parameters, including proteins, enzymes, lipids, chemicals, and minerals, were measured in serum blood samples from both diseased and healthy fish. The results indicate significant alterations in the levels of these parameters during the outbreak, highlighting the impact of infections on the blood profile of farmed rainbow trout. Urea levels were significantly higher in diseased fish compared to controls, and creatinine, phosphorus, and magnesium also showed similar trends. Alanine aminotransferase and total protein levels were higher in control fish. Chloride levels differed significantly between groups. Iron levels were higher in controls and lower in diseased fish. No significant differences were found in other parameters. This study reveals significant changes in serum blood parameters of rainbow trout during a lactococcosis outbreak caused by L. garvieae. These changes highlight the potential of these parameters as tools for monitoring health status, stress, and aquaculture management. Continuous monitoring can provide valuable insights into disease severity and overall fish health, aiding in the development of improved management practices. The presented data contribute to understanding the pathophysiology of piscine lactococcosis and developing effective mitigation strategies for farmed rainbow trout.

Copper-oxide nanoparticles effects on goldfish (Carassius auratus): Lethal toxicity, haematological, and biochemical effects

The advancement of nanotechnology and the widespread use of nanoparticles (NPs) in various industries have highlighted the importance of studying the potential harmful effects of nanomaterials on organisms. This study aimed to evaluate the lethal toxicity thresholds of Copper Oxide Nanoparticles (CuO-NPs). The investigation focused on examining the sub-lethal toxicity effects of CuO-NPs on blood parameters, as well as their influence on the gill tissue and liver of goldfish (Carassius auratus). Goldfish were exposed to varying concentrations of CuO-NPs (10, 20, 30, 40, 60, 80, and 100 mg/L) for 96 h. The Probit software was employed to determine the LC50 (lethal concentration causing 50% fish mortality) by monitoring and documenting fish deaths at 24, 48, 72, and 96-hour intervals. Subsequently, sub-lethal concentrations of 5% LC50 (T1), 10% LC50 (T2), and 15% LC50 (T3) of CuO-NPs were administered based on the LC50 level to investigate their effects on haematological parameters, encompassing the number of red blood cells and white blood cells, hematocrit and haemoglobin levels, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. Additionally, histopathological examinations were conducted on the gill and liver tissues of the studied fish. Results indicated concentration-response of fish mortalities. In general, changes in the blood biochemical parameters of fish exposed to sub-lethal concentrations of CuO-NPs included a significant decrease in leukocyte count and glucose level and an increase in protein and triglyceride levels. Furthermore, an escalation in tissue damage such as gill apical and basal hyperplasia, lamellae attachment, squamous cell swelling, blood cell infiltration, and cellular oedema in gills tissue. and bleeding, increased sinusoidal space, necrosis, lateralization of the nucleus, cell swelling, and water retention in the liver. The findings showed dose-dependent increasing toxicity in goldfish specimens exposed to CuO-NPs.

Synergistic interaction of nanoparticles and probiotic delivery: A review

Nanotechnology is an expanding and new technology that prompts production with nanoparticle-based (1-100 nm) organic and inorganic materials. Such a tool has an imperative function in different sectors like bioengineering, pharmaceuticals, electronics, energy, nuclear energy, and fuel, and its applications are helpful for human, animal, plant, and environmental health. In exacting, the nanoparticles are synthesized by top-down and bottom-up approaches through different techniques such as chemical, physical, and biological progress. The characterization is vital and the confirmation of nanoparticle traits is done by various instrumentation analyses like UV-Vis spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscopy, X-ray diffraction, atomic force microscopy, annular dark-field imaging, and intracranial pressure. In addition, probiotics are friendly microbes which while administered in sufficient quantity confer health advantages to the host. Characterization investigation is much more significant to the identification of good probiotics. Similarly, haemolytic activity, acid and bile salt tolerance, autoaggregation, antimicrobial compound production, inhibition of pathogens, enhance the immune system, and more health-beneficial effects on the host. The synergistic effects of nanoparticles and probiotics combined delivery applications are still limited to food, feed, and biomedical applications. However, the mechanisms by which they interact with the immune system and gut microbiota in humans and animals are largely unclear. This review discusses current research advancements to fulfil research gaps and promote the successful improvement of human and animal health.

The cerium oxide nanoparticles toxicity induced physiological, histological and biochemical alterations in freshwater mussels, Unio crassus

INTRODUCTION

Releasing of cerium oxide nanoparticles (nano-CeO2) to the nature has increased due to the widespread use in many fields ranging from cosmetics to the food industry. Therefore, nano-CeO2 has been included in the Organization for Economic Co-operation and Development's (OECD) priority list for engineering nanomaterials. In this study, the effects of nano-CeO2 on the freshwater mussels were investigated to reveal the impact on the freshwater systems on model organism.

METHODS

First, the chemical and structural properties of nano-CeO2 were characterized in details. Second, the freshwater mussels were exposed to environmentally relevant concentrations of nano-CeO2 as 10 mg, 25 mg and 50 mg/L during 48-h and 7-d. Third, after the exposure periods, hemolymph and tissue samples were taken to analyse the Total Hemocyte Counts (THCs) histology and oxidative stress parameters (total antioxidant status, glutathione, glutathione-S-transferase, and advanced oxidative protein products).

RESULTS

Significant decrease of the THCs was observed in the nano-CeO2 exposed mussels compared to the control group (P < 0.05). The histological results showed a positive association between nano-CeO2 exposure concentration in the water and level of tissue damage and histopathological alterations were detected in the gill and the digestive gland tissues. Oxidative stress parameters were slightly affected after exposure to nano-CeO2 (P > 0.05). In conclusion, this study showed that acute exposure of freshwater mussels to nano-CeO2 did not pose significant biological risk. However, it has been proven that mussels are able to accumulate nano-CeO2 significantly in their bodies.

CONCLUSION

This suggests that nano-CeO2 may be a potential risk to other organisms in the ecosystem through trophic transfer in the food-web based on their habitat and niche in the ecosystem.

Mitigation of haemato-genotoxic and stress response effects in Cyprinus carpio via silymarin dietary supplementation following deltamethrin exposure

The study examined the potential of Silymarin, a blend of bioactive flavonolignans extracted from the milk thistle Silybum marianum, to mitigate Deltamethrin-induced toxicity in the blood of Cyprinus carpio. Fish were exposed to Deltamethrin (0.66 μg/L), the plant extract, or a combination of both for a duration of thirty days. Various parameters, including serum biochemical markers, erythrocytic abnormalities, and genotoxicity endpoints, were assessed. Results indicated a significant (p < 0.05) increase in the levels of AST, ALT, ALP, blood urea nitrogen, creatinine, glucose, cholesterol, and TLC in the fish exposed to the pesticide. Conversely, total protein, TEC, and Hb showed a notable decrease. There was also a notable rise in micronuclei and erythrocytic abnormalities such as acanthocytes, microcytes, and notched cells. Under ultrastructural examination, phenotypic deformities like spherocytosis, discocytes, and clumped erythrocytes were observed. However, dietary supplementation of silymarin (1 g/kg) significantly restored the biochemical, genetic, and cellular parameters, resembling those of the control group. This suggests the potential of this plant extract in protecting the common carp, Cyprinus carpio, from Deltamethrin-induced damage by scavenging free radicals and reducing DNA oxidative stress.

Silver nanoparticle ecotoxicity and phytoremediation: a critical review of current research and future prospects

Silver nanoparticles (AgNPs) are widely used in various industries, including textiles, electronics, and biomedical fields, due to their unique optical, electronic, and antimicrobial properties. However, the extensive use of AgNPs has raised concerns about their potential ecotoxicity and adverse effects on the environment. AgNPs can enter the environment through different pathways, such as wastewater, surface runoff, and soil application and can interact with living organisms through adsorption, ingestion, and accumulation, causing toxicity and harm. The small size, high surface area-to-volume ratio, and ability to generate reactive oxygen species (ROS) make AgNPs particularly toxic. Various bioremediation strategies, such as phytoremediation, have been proposed to mitigate the toxic effects of AgNPs and minimize their impact on the environment. Further research is needed to improve these strategies and ensure their safety and efficacy in different environmental settings.

The toxicity effects of the individual and combined exposure of methyl tert-butyl ether (MTBE) and tire rubber powder (RP) on Nile tilapia fish (Oreochromis niloticus)

Methyl tert-butyl ether (MTBE) is soluble in water and can contaminate water sources when it spills during transportation or leaks from underground storage tanks. Incomplete combustion releases MTBE as exhaust fumes that can be deposited on urban surfaces. Meanwhile, car tires erosion emits of large amounts of rubber dust (RP), easily transported to water bodies. Therefore, this study has the objective of assessing the toxicity of varying concentrations of MTBE (0, 2.5, 5.0 μL L-1) and RP (0, 5.0, 10.0 mg L-1 RP), both individually and in combination, over a period of 28 days on Nile tilapia (Oreochromis niloticus). MTBE and PR decreased fish growth performance. Blood biochemical analytes indicated that MTBE and RP led to increasing Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and creatinine phosphokinase (CPK), alkaline phosphatase and gamma-glutamyl transferase (GGT) activities. Alterations related to glucose, triglycerides, cholesterol, and creatinine, plasma contents, were also observed. Increased antioxidant biomarkers, including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), glutathione reductase (GR), and malondialdehyde (MDA), was observed. Exposure fish to MTBE and PR changed metabolic profile of muscle tissue. Moreover, results showed that MTBE, its metabolites, and PR could accumulate in the muscle tissue of fish. Results suggest that MTBE and RP can impact fish health, both individually and when combined. The presence of MTBE enhances the toxicity of RP, indicating a synergistic effect. Nevertheless, further studies are needed to understand the impact of toxic compounds on aquatic environments and organisms' health.

Ecotoxicological insights: Effects of pesticides on ionic metabolism regulation in freshwater catfish, Mystus keletius

Fish maintain their body fluid ionic and osmotic homeostasis using sophisticated iono-/osmoregulation mechanisms through gills ionocytes. Pesticide-induced ionic imbalance in fish has been recognized as a valuable tool to determine its toxic effects. Acute exposure to synthetic and organo-chemical pesticides on the regulation of ionic (Na+, Ca2+, P) metabolism in freshwater catfish Mystus keletius was evaluated. Fish were exposed to sub-lethal concentrations (mg/l) of selected pesticide for a period of 7, 14, 21 and 28 days. Results indicated that chemical pesticides - Impala and Ekalux - evoked adverse toxic effects on selected tissues compared to organo-chemical pesticide tested. Statistical analysis of the summative data using two-way ANOVA was significant (p-value<0.001). Variations in the cellular parameters analysed were attributed to the physiological acclimatization of fish to the pesticide exposed. Based on the results it is concluded that organic pesticides may be preferred for rice field application considering safety aspects.

The Effect of Silver Nanoparticles on the Digestive System, Gonad Morphology, and Physiology of Butterfly Splitfin (Ameca splendens)

The aim of this study was to determine the effects of silver nanoparticles (AgNPs) on the morphology and enzymatic activity of butterfly splitfin (Ameca splendens). Individuals of both sexes, aged about five months, were exposed to AgNPs at concentrations of 0 (control group), 0.01, 0.1, and 1.0 mg/dm3 for 42 days. On the last day of the experiment, the fish were euthanized, subjected to standard histological processing (anterior intestine, liver, and gonads), and analysed for digestive enzyme activity in the anterior intestine and oxidative stress markers in the liver. Fish in the AgNP 0.01 and 0.1 groups had the lowest anterior intestinal fold and enterocyte height. However, there were no statistically significant changes in the digestive enzyme activity in the anterior intestine. Analysis of enzymatic activity in the liver showed an increase in superoxide dismutase activity in fish in the AgNP 0.1 group. Histological analyses showed that AgNPs inhibited meiotic divisions at prophase I in a non-linear manner in ovaries and testes. In the AgNP 0.1 and 1.0 groups, the area occupied by spermatocytes was lower compared to the other groups. These results indicate that exposure to AgNPs may lead to disturbances in morphology and enzymatic activity in the liver and intestine and may lead to disruption of reproduction in populations.

Toxic effects of sub-acute microplastic (polyamide) exposure on the accumulation, hematological, and antioxidant responses in crucian carp, Carassius carassius

The purpose of this study is to investigate the impact of microplastics (MPs) on fish and to confirm the toxic effects of MPs on fish, as well as to clarify the standard indicators. MPs are present in a large amount in the aquatic environment and can have various adverse effects on aquatic animals. Crucian carp, Carassius carassius (mean weight, 23.7 ± 1.6 g; mean length, 13.9 ± 1.4 cm), were exposed to PA (Polyamide) concentrations of 0, 4, 8, 16, 32 and 64 mg/L for 2 weeks. The PA accumulation profile in C. carassius decreased from the intestine to the gill to the liver. Hematological parameters such as red blood cell (RBC) counts, hemoglobin (Hb), and hematocrit (Ht) notably decreased at high levels of PA exposure. Plasma components such as calcium, magnesium, glucose, cholesterol, total protein, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were significantly altered by PA exposure. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and glutathione (GSH) of liver, gill and intestine significantly increased following PA exposure. The results of this study suggest that MP exposure affects the hematological physiology and antioxidant responses in C. carassius as well as accumulation in specific tissues.

Microbial degradation and transformation of PPCPs in aquatic environment: A review

The Pharmaceuticals and Personal Care Products (PPCPs) presence at harmful levels has been identified in aquatic ecosystems all over the world. Currently, PPCPs are more common in aquatic regions and have been discovered to be extremely harmful to aquatic creatures. Waste-water treatment facilities are the primary cause of PPCPs pollution in aquatic systems due to their limited treatment as well as the following the release of PPCPs. The degree of PPCPs elimination is primarily determined by the method applied for the remediation. It must be addressed in an eco-friendly manner in order to significantly improve the environmental quality or, at the very least, to prevent the spread as well as effects of toxic pollutants. However, when compared to other methods, environmentally friendly strategies (biological methods) are less expensive and require less energy. Most biological methods under aerobic conditions have been shown to degrade PPCPs effectively. Furthermore, the scientific literature indicates that with the exception of a few extremely hydrophobic substances, biological degradation by microbes is the primary process for the majority of PPCPs compounds. Hence, this review discusses about the optimistic role of microbe concerned in the degradation or transformation of PPCPs into non/less toxic form in the polluted environment. Accordingly, more number of microbial strains has been implicated in the biodegradation/transformation of harmful PPCPs through a process termed as bioremediation and their limitations.

Rainbow trout (Oncorhynchus mykiss) physiological response to microplastics and enrofloxacin: Novel pathways to investigate microplastic synergistic effects on pharmaceuticals

Enrofloxacin (ENR) is a broad-spectrum antibiotic widely used due to its efficacy against pathogens. Microplastics (MPs) may bind to ENR and reduce its efficiency, whereas there would be an increase in its toxicity, bioavailability, and bio-accumulation rates. Therefore, the hypothesis is that the interaction between MPs and ENR can alter their toxicity and bioavailability. The subjective of this study is to examine the toxicity of various concentrations of ENR (0, 1.35, and 2.7 ml Kg^-1 diet) and MPs (0, 1000, and 2000 mg Kg^-1 diet) alone and in combination for 21 days. The rainbow trout (Oncorhynchus mykiss) is an economic aquaculture species used as an experimental model in ecotoxicology studies. Blood biochemical analytes indicated that ENR and MPs combination led to increasing enzymatic activity of each biomarker, except for gamma-glutamyl-transferase (GGT). Alterations related to triglycerides, cholesterol, glucose, urea, creatinine, total protein, and albumin blood contents were observed. An elevation in the levels of superoxide dismutase (SOD), malondialdehyde (MDA), and glucose 6-phosphate dehydrogenase (G6PDH) was found in the liver. In contrast, catalase (CAT) and glutathione peroxidase (GPx) levels decreased. Furthermore, a decline was observed in the cellular total antioxidant (ANT) levels. These findings suggested that ENR and MPs could affect fish health both independently and together. Consequently, the study determined that when both ENR and MPs were present in high concentrations, the toxicity of ENR was amplified, providing further evidence of the synergistic impact of MPs on ENR toxicity.

Anti-bacterial activity of Cymbopogon citratus nanoparticles against Vibrio species infecting aquatic organisms

The presence of Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio harveyi in aquatic organisms causes vibriosis, leading to their significant mortality. The efficacy of antibiotic treatment is reduced due to increasing antibiotic resistance. As a result, novel therapeutic agents are increasingly needed to treat outbreak of such diseases in aquatic organisms and humans. This study focuses on utilizing the bioactive compounds of Cymbopogon citratus as they are rich in a variety of secondary metabolites which promotes growth, natural immune response and disease resistance against pathogenic bacteria in various ecosystems. In silico studies were performed to evaluate the binding potential of the bioactive compounds against targeted protein beta - lactamase in Vibrio parahaemolyticus and metallo - beta - lactamase in V. alginolyticus via molecular docking. Cymbopogon citratus nanoparticles (CcNps) were synthesized, characterized and toxicity studies were performed by using Vigna radiata, and Artemia nauplii at different concentrations of Cymbopogon citratus nanoparticles. The results revealed that the synthesized nanoparticles were non-ecotoxic and act as potential growth promoters in plants. The antibacterial activity of synthesized Cymbopogon citratus was evaluated using agar well diffusion method. MIC, MBC, and biofilm assays performed by using different concentrations of synthesized nanoparticles. Thus, it was proved that Cymbopogon citratus nanoparticles showed better antibacterial activity against Vibrio species.

The antibacterial activity and immunomodulatory effect of naturally synthesized chitosan and silver nanoparticles against Pseudomonas fluorescence infection in Nile tilapia (Oreochromis niloticus): An in vivo study

A sixty-day feeding trial was conducted to assess the effects of silver nanoparticles (AgNPs) and chitosan nanoparticles (CNPs) on the growth and immunity of Nile tilapia (Oreochromis niloticus), compared with the control group. CNPs and AgNPs were green synthesized and added to a control diet (30% crude protein) at levels of 2.0 g CNPs/kg diet and 1.0 mg AgNPs/kg diet. One hundred and eighty fish (101 ± 3.98 g) were randomly distributed into nine fiberglass tanks (200 cm × 200 cm x 100 cm, twenty fish each) to represent three equal groups (60 fish per group). After one and two months of the feeding trial, parameters of water quality, growth indices, hematology, and liver and kidney biomarkers were evaluated. At the end of the experiment, 10 fish from each group were challenged experimentally via the intraperitoneal injection with Pseudomonas fluorescence and fish mortality was observed for further ten days. Then, specimens from the liver, kidney, spleen, and anterior intestine were examined to assess the histopathological alterations. Incorporating a 2.0 g CNPs/kg diet was a promising growth enhancer; however, a 1.0 mg AgNPs/kg diet had no effects on tilapia performance. Furthermore, AgNPs appeared to reduce water pollution, leading to water filtration via decreasing both total dissolved solids (TDS) and electrical conductivity (EC). A significant role of AgNPs in improving tilapia^'s erythrogram (RBCs number and Hb concentration) was evident. Compared with the control group, both groups of CNPs and AgNPs improved non-specific immune parameters and showed defense effects against P. fluorescence. The fish mortality after P. fluorescence infection in CNPs and AgNPs-fed fish groups revealed significant decreases (P < 0.05) of 10% and 25%; respectively, while the control group exhibited a mortality rate of 40%. The current investigation evoked that using dietary CNPs (2.0 g/kg feed) as an antibacterial agent against P. fluorescence infection in Nile tilapia culture was better than dietary AgNPs (1.0 mg/kg diet) which, induced cells inflammation causing tissues necrosis.

Impact of acute and sub-acute exposure of magnesium oxide nanoparticles on mrigal Cirrhinus mrigala

This experiment was conducted to investigate the impact of acute and sub-acute exposure of magnesium oxide nanoparticles on Mrigal Cirrhinus mrigala. For sub-acute tests 1/100,1/50,1/10 were selected based on the LC₅₀ at 96 h s. Protein, carbohydrate, and lipid, Aspartate aminotransferase, alanine transaminase, lactate dehydrogenase and DPPH, HRSA assays were analyzed in the gill, muscle, and liver of Mrigal. Protein and lipid levels increased on the 7th,14th day compared to control. Carbohydrate levels decreased on the 7th,14th day of exposure, and the enzymatical changes increased on the 7^th,14th day. Antioxidant levels highly increased in DPPH assay compared to the HRSA assay. This study provides the biochemical, antioxidant, and behavioral changes in relation to the exposure of MgO NPs.

Toxicity of Silver Nanoparticles in the Presence of Zinc Oxide Nanoparticles Differs for Acute and Chronic Exposures in Zebrafish

We assessed the acute toxicity effects (96 h) of silver nanoparticles (Ag NPs) and zinc oxide nanoparticles (ZnO NPs) and chronic (28 d) exposure to Ag NPs, including in combination with ZnO NPs. In the chronic studies, we further assessed the toxicokinetics and bioaccumulation of Ag and the resulting histopathological effects in the gill, intestine, and liver of zebrafish. Co-exposures with ZnO NPs reduced the toxicity of Ag NPs for acute (lethality) but enhanced the toxicity effects (tissue histopathology) for chronic exposures. The histological lesions for both NPs exposures in the gill included necrosis and fusion of lamellae, for the intestine necrosis and degeneration, and in the liver, mainly necrosis. The severity of the histological lesions induced by the Ag NPs was related to the amount of accumulated Ag in the zebrafish organs. The Ag accumulation in different organs was higher in the presence of ZnO NPs in the order of the gill > intestine > liver. Depuration kinetics illustrated the lowest half-life for Ag occurred in the gill and for the combined exposure of Ag with ZnO NPs. Our findings illustrate that in addition to tissue, time, and exposure concentration dependencies, the Ag NPs toxicity can also be influenced by the co-exposure to other NPs (here ZnO NPs), emphasizing the need for more combination exposure effects studies for NPs to more fully understand their potential environmental health risks.

Impact of Camellia sinensis Iron Oxide Nanoparticle on Growth, Hemato-biochemical and Antioxidant Capacity of Blue Gourami (Trichogaster trichopterus) Fingerlings

The effect of green tea (Camellia sinensis) iron oxide nanoparticles (nano-Fe) on the effectiveness, growth, antioxidant capacity, and immunological response of Trichogaster trichopterus (Blue gourami) fingerlings was investigated. UV-Visible, Fourier Transform Infrared, Scanning Electron Microscopy, Energy Dispersive X-ray, X-ray diffraction, Dynamic Light Scattering, and Zeta Potential spectroscopy were used to evaluate the biologically synthesized nano-Fe. Characterization revealed the hexagonal and spherical morphology with an average diameter of 114 nm. Six different experimental diets were supplied to the fish in duplicate for 60 days. The first diet served as a control (no nano-Fe supplementation), whereas the remaining five diets contained nano-Fe at concentrations of 10, 20, 30, 40, and 50 mg/kg (D1 to D5). The results indicated that fish fed a nano-Fe diet at a concentration of 40 mg/kg had improved growth performance, biochemical constituents, hematological parameters, and antioxidant activity in T. trichopterus, implying that it might be used as a vital feed supplement in ornamental fish culture.

Behavioral and physiological toxicity thresholds of a freshwater vertebrate (Heteropneustes fossilis) and invertebrate (Branchiura sowerbyi), exposed to zinc oxide nanoparticles (nZnO): A General Unified Threshold model of Survival (GUTS)

The toxic effects of Zinc oxide nanoparticles (nZnO) on Branchiura sowerbyi and Heteropneustes fossilis, was assessed in a 96-hour acute exposure regime using behavioral (including loss-of balance and clumping tendencies) and physiological (mucus secretion and oxygen consumption) endpoints. While the relationship between behavioral, physiological biomarkers, and exposure concentrations was assessed using correlation analysis, nZnO toxicity was further predicted using the General Unified Threshold model for Survival (GUTS). The time-dependent lethal limits for acute nZnO toxicity (LC₅₀) on B. sowerbyi were estimated to be 0.668, 0.588, 0.448, and 0.400 mg/l, respectively, at 24, 48, 72, and 96 h whereas for H. fossilis the LC50 values are 0.954, 0.905, 0.874 and 0.838 mg/l. Threshold effect values i.e., LOEC (Lowest Observed Effect Concentration), NOEC (No Observed Effect Concentration), and MATC (Maximum Acceptable Toxicant Concentration) threshold effect values at 96 h were higher for fish compared to the oligochaete. For B. sowerbyi, the GUTS-SD (stochastic death) model is a better predictor of nanoparticle exposure effects compared to the GUTS-IT (individual tolerance) model, however in the case of H. fossilis, the reverse pattern was observed. Oxygen consumption rate was negatively correlated to mortality under acute exposure duration. The strong negative correlation between mortality and oxygen consumption strongly suggests a metabolic-toxicity pathway for nZnO exposure effects. The higher toxicity threshold values i.e., LOEC, NOEC, and MATC for fish compared to the oligochaete invertebrate indicates greater risks for invertebrates compared to vertebrates, with resultant implications for local habitat trophic relationships.

Silver nanoparticles induced hepatoxicity via the apoptotic/antiapoptotic pathway with activation of TGFβ-1 and α-SMA triggered liver fibrosis in Sprague Dawley rats

Despite the extraordinary use of silver nanoparticles (AgNPs) in medicinal purposes and the food industry, there is rising worry about potential hazards to human health and the environment. The existing study aims to assess the hepatotoxic effects of different dosages of AgNPs by evaluating hematobiochemical parameters, oxidative stress, liver morphological alterations, immunohistochemical staining, and gene expression to clarify the mechanism of AgNPs' hepatic toxic potential. Forty male Sprague Dawley rats were randomly assigned into control and three AgNPs intraperitoneally treated groups 0.25, 0.5, and 1 mg/kg b.w. daily for 15 and 30 days. AgNP exposure reduced body weight, caused haematological abnormalities, and enhanced hepatic oxidative and nitrosative stress with depletion of the hepatic GSH level. Serum hepatic injury biomarkers with pathological hepatic lesions where cholangiopathy emerges as the main hepatic alteration in a dosage- and duration-dependent manner were also elevated. Furthermore, immunohistochemical labelling of apoptotic markers demonstrated that Bcl-2 was significantly downregulated while caspase-3 was significantly upregulated. In conclusion, the hepatotoxic impact of AgNPs may be regulated by two mechanisms, implying the apoptotic/antiapoptotic pathway via raising BAX and inhibiting Bcl-2 expression levels in a dose-dependent manner. The TGF-β1 and α-SMA pathway which triggered fibrosis with incorporation of iNOS which consequently activates the inflammatory process were also elevated. To our knowledge, there has been no prior report on the experimental administration of AgNPs in three different dosages for short and long durations in rats with the assessment of Bcl-2, BAX, iNOS, TGF-β1, and α-SMA gene expressions.

Metallic and non-metallic nanoparticles from plant, animal, and fisheries wastes: potential and valorization for application in agriculture

Global agriculture is facing tremendous challenges due to climate change. The most predominant amongst these challenges are abiotic and biotic stresses caused by increased incidences of temperature extremes, drought, unseasonal flooding, and pathogens. These threats, mostly due to anthropogenic activities, resulted in severe challenges to crop and livestock production leading to substantial economic losses. It is essential to develop environmentally viable and cost-effective green processes to alleviate these stresses in the crops, livestock, and fisheries. The application of nanomaterials in farming practice to minimize nutrient losses, pest management, and enhance stress resistance capacity is of supreme importance. This paper explores innovative methods for synthesizing metallic and non-metallic nanoparticles using plants, animals, and fisheries wastes and their valorization to mitigate abiotic and biotic stresses and input use efficiency in climate-smart and stress-resilient agriculture including crop plants, livestock, and fisheries.

Enhanced photodegradation of methylene blue from aqueous solution using Al-doped ZnS nanoparticles

The post-transition semiconducting material of pure zinc sulfide (ZnS) and various concentrations of aluminum (Al) (2.5 wt%, 5.0% wt, 7.5 wt%, and 10% calcined at 200 °C) doped ZnS nanoparticles (NPs) were synthesized by sol-gel procedure. The crystal-like nature and phase structure of the product were examined by powder XRD analysis. This analysis shows that the pure ZnS nanoparticle does not form any secondary phase. The functional group of synthesized materials was analyzed by FTIR examination. The energy gap of the materials is calculated using electro-optic analysis and the Kubelka-Munk equation varies from 3.04 nm to 3.63 nm. The photoluminescence studies show the wide emissions (blue to green) for pure ZnS and Al-doped ZnS nanomaterials. The SEM images show the spherical structure and the agglomerated nanostructures. The presence of Zn, S, and Al are confirmed by EDAX spectra. From HR-TEM studies, pure ZnS and Al-doped ZnS nanoparticles exhibit uniform particle sizes. The rate of degradation was observed using MB dye. MB dye has maximum wavelength (λ_max) of 664 nm. The dye degradation efficiency was improved as the dye ratio increased. Photocatalytic activities studies show the intensity of photocatalytic activities decreased for the maximum time interval. Doping of Al in ZnS boosts the photocatalytic activity. Hence, Al-doped ZnS appears to be better decomposing MB dye when exposed to visible light.

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.

Ecotoxicological Effects of Pesticides on Hematological Parameters and Oxidative Enzymes in Freshwater Catfish, Mystus keletius

Hematological parameters and changes in stress-induced functionalities of cellular enzymes have been recognized as valuable tools for monitoring fish health and determining the toxic effects of pesticides. The present study was conducted to evaluate the toxic effect of selected pesticides viz., Ekalux (EC-25%), Impala (EC-55%), and Neemstar (EC-15%) on freshwater catfish Mystus keletius. Fish were exposed to sub-lethal concentrations (mg/L) of the selected pesticide for a period of 7, 14, 21, and 28 days. Hematological parameters viz., total erythrocyte (RBC), hemoglobin (Hb), and hematocrit (Ht) packed cell volume values decreased with an increase in exposure time to pesticides, whereas the values for parameters viz., leucocytes (WBC), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) increased significantly. A decrease in packed cell volume (PCV) and hemoglobin values coupled with decreased and deformed erythrocytes as signs of anemia were also observed. The effect of pesticides on RBC content was 1.43 (million/mm3) on day 7 and reduced to 1.18 (million/mm3) on days 14 and 21. A similar trend was found for Impala on RBC, which had an initial value of 1.36 (million/mm3) on day 7 and reached a value of 1.10 (million/mm3) on day 28. In contrast, the value of Neemstar decreased from 1.59 (million/mm3) on day 7 in control to 1.02 (million/mm3) on day 28. Data indicates that the order of toxic effect of pesticides recorded a maximum for Impala followed by Ekalux and Neemstar in the selected fish model. Likewise, the overall pattern of pesticidal activity on cellular enzymes (GDH, MDH, and SDH) recorded a maximum toxic effect for Impala followed by Ekalux and Neemstar. Results indicate that Chlorpyrifos pesticide-Impala evoked maximum toxic effect on selected tissues compared to the other two pesticides tested. Statistical analysis of the summative data using two way ANOVA was statistically significant (p-value < 0.001). The differences in the hematological parameters analyzed are attributed to the physiological acclimatization of the fish to the local conditions, which influences the energy metabolism and consequently determines the health status of the fish. Overall, Impala exhibited the highest pesticidal activity on cellular enzyme, followed by Ekalux and Neemstar. Results suggest that natural pesticides may be preferable for rice field application in terms of environmental safety.

Effects of Diazinon on the Survival, Blood Parameters, Gills, and Liver of Grass Carp (Ctenopharyngodon idella Valenciennes, 1844; Teleostei: Cyprinidae)

Diazinon (DZN) is a widely used pesticide that can affect the vital organs of non-target aquatic animals—mainly fish. This study evaluated the acute toxicity (LC50) of six DZN concentrations (0.5, 0.75, 1.5, 2, 2.5, and 3 mg·L−1) and, based on its evaluation after 24 h, 48 h, 72 h, and 96 h, two sublethal concentrations for chronic toxicity testing (0.01 and 0.05 mg·L−1) for 21 days of exposure to DZN on grass carp fingerlings (Ctenopharyngodon idella Valenciennes, 1844). The median lethal concentrations of DZN at 24, 48, 72, and 96 h were 1.83, 1.57, 1.35, and 1.12 mg·L−1, respectively. Next, histological observations after 96 h LC50 showed oedema of the primary lamellae of the gills at low pesticide concentrations (0.5 to 1 mg·L−1) and extensive necrosis of primary lamellae of the gills at higher concentrations (1.5 to 3 mg·L−1). Moreover, cytoplasmic vacuolation and extensive necrosis were observed in liver tissue. Increased skin mucus, unbalanced swimming on the water surface, and increased gill opercula movements were noted during chronic exposure. Haematological parameters such as haematocrit, red blood cell count, white blood cell count, haemoglobin, and mean corpuscular volume were significantly reduced after 21 days of exposure to 0.05 mg·L−1 of DNZ (p < 0.05). The present study shows that DZN has various toxic effects on grass carp, which may pose a potential risk for other fish species.

Modulatory Effect of Papaya Extract against Chlorpyrifos-Induced Oxidative Stress, Immune Suppression, Endocrine Disruption, and DNA Damage in Female Clarias gariepinus

Chlorpyrifos (CPF) is one of the widely used organophosphorus pesticides in agriculture activities and its presence in the aquatic environment has been broadly recorded. In the present study, we investigated the effect of CPF exposure on oxidative stress, innate immunity, sexual hormones, and DNA integrity of female African catfish, Clarias gariepinus, in addition to the potential use of dietary supplementation of papaya, Carica papaya (CP), extract against CPF toxicity. Apparent healthy female catfish (300 ± 10 g) were divided into four groups with three replicates each. The first group served as the negative control (fed on a basal diet) and the other groups exposed to CPF (8.75 µg/L) with or without CP extract (250 mg/kg body weight) for six weeks. The results revealed that CPF exposure exhibited marked elevations in stress markers (glucose and cortisol), serum aspartate aminotransferase, alanine aminotransferase activities, testosterone, and luteinizing hormone level. Moreover, CPF increased the percentage of hepatic DNA damage. In addition, catfish exposed to CPF experienced significant decline in serum total protein, albumin, follicles stimulating hormone, estradiol hormone levels, AChE, immunoglobulin, and lysozyme activity. CPF induced significantly oxidative stress in hepatic and renal tissues. The dietary supplementation with CP extract at a level of 250 mg/kg body weight succeeded to alleviate the negative effects of CPF on the physiological, immunological, and antioxidant status of female catfish. In addition, CP extract alleviated the endocrine disruption and hepatic DNA damage and counteracted the subchronic CPF toxicity in female African catfish. Finally, the CP extract may be used as a feed additive in the aquatic diet.

Commonly used surfactants sodium dodecyl sulphate, cetylpyridinium chloride and sodium laureth sulphate and their effects on antioxidant defence system and oxidative stress indices in Cyprinus carpio L.: an integrated in silico and in vivo approach

The present study evaluated the homology modelling, in silico prediction and characterization of Cyprinus carpio cytochrome P450, as well as molecular docking experiments between the modelled protein and the surfactants sodium dodecyl sulphate (SDS), sodium laureth sulphate (SLES) and cetylpyridinium chloride (CPC). Homology modelling of cytochrome P450 was performed using the best fit template structure. The structure was optimized with 3D refine, and the ultimate 3D structure was checked with PROCHEK and ERRATA. ExPASy's ProtParam was likewise used to analyse the modelled protein's physiochemical and stereochemical attributes. To establish the binding pattern of each ligand to the targeted protein and its effect on the overall protein conformation, molecular docking calculations and protein-ligand interactions were performed. Our in silico analysis revealed that hydrophobic interactions with the active site amino acid residues of cytochrome p450 were more prevalent than hydrogen bonds and salt bridges. The in vivo analysis exhibited that exposure of fish to sublethal concentrations (10% and 30% of 96 h LC₅₀) of SDS (0.34 and 1.02 mg/l), CPC (0.002 and 0.006 mg/l) and SLES (0.69 and 2.07 mg/l) at 15d, 30d and 45d adversely affected the oxidative stress and antioxidant enzymes (CAT, SOD, GST, GPx and MDA) in the liver of Cyprinus carpio. As a result, the study suggests that elicited oxidative stress, prompted by the induction of antioxidant enzymes activity, could be attributable to the stable binding of cytochrome P450 with SDS, CPC and SLES which ultimately leads to the evolution of antioxidant enzymes for its neutralization.

Investigation of the impact caused by different sizes of polyethylene plastics (nano, micro, and macro) in common carp juveniles, Cyprinus carpio L., using multi-biomarkers

Plastic pollution poses a global threat to aquatic organisms, yet its effect on many species remains poorly documented and understood. This study addresses the impact caused by different sizes of polyethylene (PE) plastics on the common carp and evaluates their multi-biomarkers response. We investigated the histological structure and measurement of biochemical alterations, antioxidant enzymes, immunological responses, and fluctuations in blood profiles of the organisms after 15 days of exposure to a concentration of 100 mg/L of nano- (NPs), micro- (MPs) and macroplastics (MaPs). The fish health status was altered in the sole presence of PE particles. All biomarkers changed after exposure compared to the control group, with larger changes being observed with the decreasing size of particles (NPs > MPs > MaPs) compared to their absence. A synergistic effect resulting from the individual impact of plastics penetration in the circulatory system, bursting biochemical responses, and lesions in tissues, might explain the more considerable impact of NPs compared to MPs and/or MaPs.

Ecotoxicological Effects of Silver Nanoparticles (Ag-NPs) on Parturition Time, Survival Rate, Reproductive Success and Blood Parameters of Adult Common Molly (Poecilia sphenops) and Their Larvae

Nanoparticles (NPs) can display toxicological effects on aquatic organisms. This study investigates ecotoxicological effects of Ag-NPs on reproductive and blood parameters of adult common molly (Poecilia sphenops) and their larvae. During the LC50 96 h test, female fish were exposed to concentrations of 0, 5, 15, 25, 35, 45 and 60 mg L−1 of Ag-NPs, while larvae were exposed to 0, 3, 5, 10 and 15 mg L−1. Finally, we aim to evaluate the effects of 0, 5, 10 and 15 mg L−1 of Ag-NPs on parturition time, reproductive success and hematological parameters of the mature fish exposed to sub-lethal concentration during a 62-day period. We also evaluated the survival rate of larvae. The results show a positive correlation between mortality rate and Ag-NP concentration. Values for LC50 96 h in adult fish and larvae were 26.85 mg L−1 and 6.22 mg L−1, respectively. A lack of parturition and reproductive success were seen in fish that underwent chronic exposure to Ag-NPs (15 mg L−1). The results show that RBC, WBC and hematocrit were significantly decreased in fish exposed to Ag-NPs. In addition, the serum concentrations of total protein, albumin, cholesterol and triglycerides were significantly increased in fish submitted to Ag-NPs (concentrations of 5–15). In conclusion, submitting a fish to higher concentration than 10 mg L−1 has adverse effects on reproductive system and blood parameters.

Nano-silica and magnetized-silica mitigated lead toxicity: Their efficacy on bioaccumulation risk, performance, and apoptotic targeted genes in Nile tilapia (Oreochromis niloticus)

Contamination of aquatic systems with heavy metals (HM) is of great concern owing to their deleterious impact on living organism. The current research is focused on application of silica particles with new functionalized properties (magnetic silica; SiMag or Nanoporous silica; SiNPs) and their efficacy to mitigate lead (pb) toxicity in Nile tilapia. One thousand fingerlings were distributed: two control groups (negative; without pb toxicity (NC) positive (with pb toxicity) and other four groups received two silica sources (SiMag or SiNPs) with two levels (400 and 600 mg/kg diet) for 56 days then exposed to pb for 30 days. Before toxicity exposure, maximum growth, and most improved feed conversion ratio and biochemical parameters were noticed with higher SiMag or SiNPs levels. Serum antioxidant enzymes and their transcriptional levels in muscle and liver were boosted in groups received SiMag or SiNPs. After toxicity exposure, hematological and antioxidants biomarkers maintained at adequate levels in SiMag or SiNPs. Prominent reduction of residual pb in gills, liver, kidney, and muscle was observed in SiNPs then SiMag groups. Interestingly, the maximum down-regulation of P450, caspase-3 and HSP-70 and MT were observed in groups received 600 mg/kg diet of SiMag or SiNPs. The higher level of P53 in liver and gills was detected in PC, inversely reduced in SiMag or SiNPs. Severity of the histopathological alterations in examined organs greatly reduced in groups received SiMag or SiNPs, unlike it were induced in PC group. In conclusion, higher SiMag or SiNPs levels not only mitigate negatives impact of pb toxicity in fish but also ensure its safety for human consumption.

Hematological and Hematopoietic Effects of Bactericidal Doses of Trans-Cinnamaldehyde and Thyme Oil on Cyprinus carpio Juveniles

The effects of two potential antibacterial agents of plant origin: trans-cinnamaldehyde (TC) and thyme oil (TO) on the peripheral blood parameters and cellular composition of hematopoietic tissue of Cyprinus carpio were studied. Both phytochemicals were used in the doses based on the bactericidal concentrations against Aeromonas spp. developed earlier in in vitro study. The fish were fed for 2 weeks on a commercial feed supplemented with 10 μl/kg of TC or 20 μl/kg of TO. Groups TC1 and TO1 were fed diets containing phytochemicals daily, while groups TC2 and TO2 every 2 days. Control group and groups TC2 and TO2 on the remaining days were fed plain feed. Peripheral blood and head kidney hematopoietic tissue were sampled from all the fish at the end of the experiment. In all the groups, hematological values were within the reference ranges for the healthy common carp juveniles. However, blood hemoglobin (Hb) concentration and mean corpuscular hemoglobin concentration (MCHC) were significantly lower in all the groups exposed to TC and TO, while MCH in TC1, TO1, and TO2 compared to the control. TC and TO did not affect leukocyte count [white blood cell (WBC)], differential leukocyte count, the oxidative activity of phagocytes [nitroblue tetrazolium (NBT)], or thrombocyte count (Thro). No significant alterations were observed in the hematopoietic tissue. The results showed that TC and TO exhibited no considerable hematotoxic effects and trials of their use in the treatment of fish infected with Aeromonas spp. may be undertaken.

Imperative role of electron microscopy in toxicity assessment: A review

Electron microscope (EM) was developed in 1931 and since then microscopical examination of both the biological and non-biological samples has been revolutionized. Modifications in electron microscopy techniques, such as scanning EM and transmission EM, have widened their applicability in the various sectors such as understanding of drug toxicity, development of mechanism, criminal site investigation, and characterization of the nano-molecule. The present review summarizes its role in important aspects such as toxicity assessment and disease diagnosis in special reference to SARS-COV2. In the biological system, EM studies have elucidated the impact of toxicants at the ultra-structural level in various tissue in conformity to physiological alterations. Thus, EM can be concluded as an important tool in toxicity assessment and disease prognosis.

Effects of sodium butyrate nanoparticles on the hemato-immunological indices, hepatic antioxidant capacity, and gene expression responses in Oreochromisniloticus

Recently, nanotechnology has been greatly developed to provide the aquaculture industry with new beneficial nanomaterials to improve the health and welfare of aquatic animals. Herein, an eight-week experiment was designed to examine the dietary impacts of sodium butyrate nanoparticles (SB-NPs) on the hematological profile, blood proteins, immunological indices, antioxidant capacity, and expression analysis of cytokines and antioxidant-related genes in Oreochromis niloticus. Fish were randomly assigned into 5 experimental groups (3 replicates per group) and were fed diets supplemented with 5 levels of SB-NPs as 0.0 (control), 0.5, 1.0, 1.5, and 2.0 mg kg^-1. The results revealed that supplementing diets with SB-NPs (1.0-2.0 mg kg^-1) significantly elevated erythrocyte and leukocyte counts, hemoglobin concentrations, hematocrit values, total albumin, globulin, serum lysozyme activities, and total immunoglobulin M values compared with the control group. Notably, the highest levels of the parameters mentioned above were noticed in the group fed diet supplemented with 1.5 mg kg^-1 SB-NPs. Moreover, dietary SB-NPs modulated the fish's antioxidant defense mechanisms, whereas there was a significant increase in hepatic superoxide dismutase, catalase, and glutathione peroxidase enzyme activities along with a significant decline in hepatic malondialdehyde concentrations in fish groups fed diets supplemented with SB-NPs (1.0-2.0 mg kg^-1). A significant upregulation of antioxidant enzyme genes (gpx and sod), anti-inflammatory cytokine (il-10), and pro-inflammatory cytokines (il-1β and il-8) were noticed in liver tissues of SB-NPs groups (0.5-1.5 mg kg^-1). The highest mRNA expression folds of the above genes were recorded in the fish group fed diet supplemented with 1.5 mg kg^-1 SB-NPs. In this context, we hypothesized that dietary supplementation with SB-NPs can boost the antioxidant status and immunity of O. niloticus. However, further research studies are still recommended.

Cytopathological and ultrastructural changes in the male reproductive organs of freshwater crab Paratelphusa jacquemontii (Rathbun) exposed to nurocombi

Accumulation of pollutants in the aquatic system has a high impact on the reproductive physiology of crustaceans. The objective of the present study was to assess the possible histopathological effects of combined chlorpyrifos and cypermethrin (nurocombi) exposure on reproductive tissue in male freshwater crab Paratelphusa jacquemontii using light and electron microscopy. The testis of experimental crabs showed disorganization of testicular lobules, increased inters cellular space, necrosis, and cellular damage in both germinal cells and Sertoli cells. The treated vas deferens exhibited epithelial degeneration, misshaped spermatophores, decline in the number of spermatophores, and dehiscence of spermatophore wall. These clinical manifestations expressed in crabs following the exposure of nurocombi significantly reduce the testicular activity and substantially inhibits the seminal secretions, which ultimately lead to impairment of reproduction.

Evaluation of Behavioral Changes and Tissue Damages in Common Carp (Cyprinus carpio) after Exposure to the Herbicide Glyphosate

Pesticides can induce changes in behavior and reduce the survival chance of aquatic organisms. In this study, the toxic effects of glyphosate suspension (Glyphosate Aria 41% SL, Tehran Iran) on behavior and tissues of common carp (Cyprinus carpio) were assessed. For this purpose, a 96 h LC₅₀ of glyphosate suspension (68.788 mL·L^-1) was used in the toxicity test. All individuals were divided into control and treatment groups with four replicates. Exposure operations were performed under two conditions: increasing concentration of suspension from 0 to 68.788 mL·L^-1; then, decreasing to the first level. The swimming pattern was recorded by digital cameras during the test and tissue samples were collected at the end of the test. There were significant differences between the swimming pattern of treated individuals and control ones during both steps. The sublethal concentration of glyphosate led to hypertrophy, hyperplasia and hyperemia in the gill of fish. However, changes were obvious only after sampling. The exposed fish also displayed clinical signs such as darkening of the skin and increasing movement of the operculum. Moreover, glyphosate suspension affected swimming patterns of fish suggest that the swimming behavior test can indicate the potential toxicity of environmental pollutants and be used as a noninvasive, useful method for managing environmental changes and assessing fish health conditions by video monitoring.

Cassia fistula ameliorates chronic toxicity of cypermethrin in Catla catla

Protective effects of Cassia fistula, in Catla catla exposed to synthetic pyrethroid cypermethrin were evaluated. Fish, after chronic exposure to environmentally relevant sub-lethal concentration 0.41 μg/l of the pesticide were assessed for antioxidant activity, histopathological and ultrastructural alterations. Significant (p < 0.05) decrease in the activities of antioxidants such as CAT, SOD, GST, GSH was registered, whereas LPO level got elevated. Histological damage depicted necrosis, epithelial hypertrophy, hyperplasia and fusion of secondary lamellae and changes in gill vasculature. Histopathological alteration index was employed for the semi quantitative evaluation of the degree of tissue change (DTC). Transmission electron microscopy displayed swollen and distorted mitochondria, damaged chloride cells and necrosis. Dietary supplementation of Cassia fistula bark extract significantly (p < 0.05) improved the antioxidant activity, reduced lipid peroxidation and prevented histopathological alterations. The findings suggest that sub-lethal concentration of cypermethrin is toxic to fish. The study also draws attention towards potential of plant derived antioxidants in mitigating pesticide induced toxic effects.

Assessment of the effect of long-term exposure to microplastics and depuration period in Sparus aurata Linnaeus, 1758: Liver and blood biomarkers

The constant increase in plastic pollution has attracted great attention in recent years due to its potential detrimental effects on organisms and ecosystems. While the consequences of ingestion of large plastic litter are mostly understood, the impacts resulting from a long-term exposure and a recovery period of microplastics (MPs) are still limited. The aims were to monitor oxidative stress, detoxification and inflammatory biomarkers in liver, plasma and erythrocytes of Sparus aurata exposed during 90 days to low-density polyethylene (LDPE)-MPs enriched diet (10% by weight) followed by 30 days of depuration. Exposure to LDPE-MPs progressively activates the antioxidant and detoxification system and induces an inflammatory response in liver and plasma, whereas no significant changes were observed in erythrocytes. The plasma activities of catalase, myeloperoxidase (MPO), lysozyme and the levels of malondialdehyde (MDA) as maker of lipid peroxidation significantly increased after exposure to LDPE-MPs for 90 days compared to the control group. The activities of all antioxidant enzymes - catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase-, the detoxification enzyme glutathione s-transferase, MPO, the production of reactive oxygen species and the levels of MDA were also significantly increased in liver after MPs exposure. Additionally, all these biomarkers tended to recover during the depuration period, most of them reaching similar levels to those of the control group. In conclusion, the ingestion of a diet containing LDPE-MPs for 90 days induced a progressive increase in oxidative stress and inflammation biomarkers in liver and plasma of S. aurata but not in erythrocytes, which tended to regain control values when not exposed to MPs for 30 days. The present study contributes to a better understanding of the toxic effects of MPs in S. aurata and highlights the usefulness of plasma that can be obtained in a minimally invasive way to monitor these effects.

Protective Effect of Emblica officinalis in Cyprinus carpio against Hepatotoxicity Induced by Malachite Green: Ultrastructural and Molecular Analysis

Malachite green (MG) dye, besides coloring is used as an effective aquaculture therapeutic. The present study assesses the mitigating ability of Emblica officinalis (EO) fruit extract against the dye induced chronic (60 days) cyto-toxicity in Cyprinus carpio. For this, four experimental groups were maintained: group I—control, group II—MG, group III—EO (positive control), group IV—MG + EO. The study was made at three tiers: detailing structural anomalies using a light microscope and transmission electron microscope (TEM), biochemical estimation of antioxidant enzymes, and lipid peroxidation and molecular analysis of expression patterns of HSP70, and CYP1A genes. MG intoxication resulted in necrosis, cytoplasmic vacuolation, glycogen depletion, abundant macrophages, loss of cell integrity and prominent nuclear alterations. Significant (p < 0.05) inhibition in the activities of catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST) and reduced glutathione (GSH), along with an elevation in malondialdehyde (MDA) levels, occurred after 60 days of MG exposure. CYP1A and HSP70 genes presented a significant change in their expression in MG treated fish. Whereas oral supplementation with EO significantly restored the histo-architecture, normalized the altered enzymatic activity, reduced the oxidative stress level and regulated the expression of HSP70 and CYP1A genes. Thus, it can be concluded that EO acted as an effective ameliorant against malachite green induced cyto-toxicity in Cyprinus carpio.

Chemically and Green Synthesized ZnO Nanoparticles Alter Key Immunological Molecules in Common Carp (Cyprinus carpio) Skin Mucus

This study was conducted to compare the effects of commercially available (C) and green synthesized (GS) Zinc oxide nanoparticles (ZnO-NPs) on immunological responses of common carp (Cyprinus carpio) skin mucus. GS ZnO-NPs were generated using Thymus pubescent and characterized by UV–vis diffuse reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). Fish (n = 150) were randomly allocated into five groups in triplicate and received a waterborne concentration of 0% (control), 25%, and 50% of LC50 96 h of commercially available (C1 and C2) and green synthesized ZnO-NPs (GS1 and GS2) for 21 days. Results from XRD displayed ZnO-NPs with 58 nm in size and UV-vis DRS, EDX, and FT-IR analysis showed that some functional groups from plant extract bonded to the surface of NPs. The SEM images showed that ZnO-NPs have conical morphology. Acute toxicity study showed a higher dose of LC50_96h for green synthesized ZnO-NPs (78.9 mg.L⁻¹) compared to the commercial source (59.95 mg.L⁻¹). The highest activity of lysozyme and alternative complement activity (ACH50) were found in control and GS1 groups. A significant decrease in alkaline phosphatase activity (ALP) was found in C1 and C2 groups compared to other treatments. Protease activity (P) was significantly decreased in the C2 group compared to the control and GS groups. Total immunoglobulin (total Ig) content was the highest in the control. In addition, total Ig in the GS1 group was higher than GS2. The exposure to ZnO-NPs lowered total protein content in all experimental groups when compared to control. Present findings revealed lower induced immunosuppressive effects by green synthesized ZnO-NPs on key parameters of fish skin mucus.

Effects of SiO2 nanoparticles on the uptake of tetrabromobisphenol A and its impact on the thyroid endocrine system in zebrafish larvae

The coexistence of nanoparticles and organic toxicants in the environment modifies pollutant bioavailability and toxicity. This study investigated the influence of silicon dioxide nanoparticles (n-SiO₂) on the uptake of tetrabromobisphenol A (TBBPA) and its impact on the thyroid endocrine system in zebrafish larvae. Zebrafish (Danio rerio) embryos were exposed to TBBPA at different concentrations (50, 100, and 200 μg/L) alone or in combination with n-SiO₂ (25 mg/L) until 120 h post-fertilization (hpf). Chemical measurements showed that both TBBPA and n-SiO₂ were bioconcentrated in zebrafish larvae, and the uptake of TBBPA was enhanced by n-SiO₂. Furthermore, zebrafish larvae exposed to 200 μg/L TBBPA alone exhibited significantly increased T4 contents and decreased T3 contents, whereas n-SiO₂ treatment alone did not have a detectable effect. Furthermore, the thyroid hormone levels changed more upon treatment with 200 μg/L TBBPA combined with 25 mg/L n-SiO₂ than upon TBBPA treatment alone. Alterations in gene transcription along the related hypothalamic-pituitary-thyroid (HPT) axis were observed, and expression of the binding and transport protein transthyretin (TTR) was significantly decreased for both TBBPA alone and co-exposure with n-SiO₂. Thus, the current study demonstrates that n-SiO₂, even at the nontoxic concentrations, increases thyroid hormone disruption in zebrafish larvae co-exposed to TBBPA by promoting its bioaccumulation and bioavailability.

Acanthocephalans parasites of two Characiformes fishes as bioindicators of cadmium contamination in two neotropical rivers in Brazil

Studies have demonstrated the role of acanthocephalan as environmental bioindicators. The dynamics in the parasite-host relationship that define the patterns of distribution of trace metals in parasites and, in its host, are extremely variable. In addition, the neotropical region, which is a major maintainer of the biodiversity of fish and parasites, remains little explored in this subject. Therefore, our objective was to analyze and compare the concentration of Cadmium (Cd) in the tissues of Prochilodus lineatus and Serrasalmus marginatus collected from Baía and Paraná rivers, as well as to assess the use of acanthocephalan as environmental bioindicators of pollution and their Cd bioaccumulation capacity. We collected 53 fish, 20 specimens of Prochilodus lineatus from Paraná River and 17 from Baía River, in addition to 16 specimens of Serrasalmus marginatus from Baía River, in September 2017 and March 2018. Tissues of the fish along with their parasites were subjected a Cd concentration analysis by Atomic Absorption Spectroscopy. The results revealed that the parasites had higher concentrations than all the tissues of S. marginatus, P. lineatus from Baía River and Paraná River. The high Cd concentrations in these parasites derived from their bioaccumulation capacity, because of the absorption of nutrients directly from the intestinal content of the fish through the tegument, as well as for the presence of Cd on the surface waters of Praná River floodplain. Besides that, the Coefficient of Spearman Rank Correlation showed that the infrapopulation size seems to affect Cd bioaccumulation in the parasites, smaller infrapopulations demonstrate a higher accumulation capacity compared to the larger ones. With that, we concluded that the two acanthocephalans species analyzed in this study have a good capacity for Cd accumulation, and can be used as accumulation indicators of trace-metal pollution. Accumulation indicators provide important information on the biological availability of pollutants.

Invertebrate responses to microplastic ingestion: Reviewing the role of the antioxidant system

Microplastic ingestion in invertebrates reduces somatic and reproductive growth. This could be caused by energy reserves being detracted from growth processes and redistributed to maintenance processes that preserve life. A potential sink for this diverted energy is the antioxidant system, which minimises oxidative damage and reinstates redox homeostasis following disturbances caused by exposure to pollution. Several microplastic studies have used genetic and molecular redox biomarkers to assess how microplastic ingestion affects the functioning of the antioxidant system. This systematic review synthesises the current understanding of redox biomarker responses in invertebrates that have ingested microplastics. We found that biomarker response information exists for only seven invertebrate taxa, and early life stages have received little scientific attention. The microplastics used by most studies were polystyrene (45% of studies), spherical (51% of studies), and were < 10 μm in diameter (31% of studies). We found multiple examples of microplastic ingestion posing an oxidative challenge to invertebrates, which required upregulation of antioxidant system components. However, the lack of systematic experiments prevented us from clearly identifying which characteristic of microplastics caused these responses. We identify several areas for consideration when investigating biomarker responses to microplastic ingestion and offer research priorities for future studies.

Comparative evaluation of two anticoagulants used for the analysis of haematological, biochemical parameters and blood cell morphology of himalayan snow trout, Schizopyge plagiostomus

The aim of the present study is to evaluate the effect of lithium heparin and K₂EDTA on haematology, biochemical parameters and blood cell morphology of snow trout Schizopyge plagiostomus inhabiting in Kashmir Himalayan region. The haematological parameters such as hemoglobin (Hb), red blood cellcount (RBC), white blood cell (WBC), haematocrit (Hct), erythrocyte indices; mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), produced certain significant differences in their values with respect to both anticoagulants. Higher values of Hct, MCH and MCV while lower RBC count and MCHC values were recorded with a sample treated with K₂EDTA compared to sample treated with lithium heparin. However, no significant change in Hb and WBC count was observed in the values of samples treated with both the anticoagulants. In the present study, the effect of two anticoagulant in biochemical parameters revealed that the alkaline phosphatase (ALP) and aspartate transaminase (AST) produced significant (P < 0.05) differences. Higher AST and lower ALP activity were recorded in the sample treated with K₂EDTA compared to overall values in serum. Morphometric analysis showed an increase in the RBC perimeter area in samples treated with K₂EDTA as compared to samples treated with lithium heparin. On the basis of above findings, it is recommended that in fish blood analysis heparin as anticoagulant could be useful as compared to K₂ EDTA.

Role of Beetroot (Beta vulgaris) Juice on Chronic Nanotoxicity of Silver Nanoparticle-Induced Hepatotoxicity in Male Rats

Introduction

Nanoparticles are at the forefront of rapidly developing nanotechnology and have gained much attention for their application as an effective drug delivery system and as a mediated therapeutic agent for cancer. However, the cytotoxicity of nanoparticles is still relatively unknown and, therefore, additional study is required in order to elucidate the potential toxicity of these nanoparticles on cells.

Materials and Methods

Thus, the following work aimed to investigate the capability of Beta vulgaris (beetroot) water extract (BWE; 200 mg/kg) to protect hepatic tissue following silver nanoparticles (AgNPs; 80 mg/kg; >100 nm) intoxication in male rats.

Results

AgNPs-intoxication elevated the liver function markers – including serum transaminases and alkaline phosphatase activities – and decreased serum levels of albumin and total proteins, in addition to disturbing the oxidation homeostasis. This is evidenced by the increased lipid peroxidation, the depleted glutathione, and the suppressed activity of superoxide dismutase and catalase. In addition, an apoptotic reaction was observed following AgNPs treatment, as indicated by the up-regulation of p53 and down-regulating Bcl-2 expressions, examined by the immunohistochemistry method. Furthermore, AgNPs exhibited a marked elevation in liver DNA damage that was indicated by an increase in tail length, tail DNA% and tail movement. However, BWE eliminated the biochemical and histological alterations, reflecting its hepatoprotection effect in response to AgNPs.

Discussion

Collectively, the present data suggest that BWE could be used following AgNPs as a potential therapeutic intervention to minimize AgNPs-induced liver toxicity.

High synergistic antibacterial, antibiofilm, antidiabetic and antimetabolic activity of Withania somnifera leaf extract-assisted zinc oxide nanoparticle

Nanotechnology is currently gaining immense attention to combat food borne bacteria, and biofilm. Diabetes is a common metabolic disease affecting majority of people. A better therapy relies on phytomediated nanoparticle synthesis. In this study, W. somnifera leaf extract-assisted ZnO NPs (Ws-ZnO NPs) was synthesized and characterized. From HR-TEM analysis, it has been found that the hexagonal wurtzite particle is 15.6 nm in size and - 12.14 mV of zeta potential. A greater antibacterial effect of Ws-ZnO NPs was noticed against E. faecalis and S. aureus at 100 µg mL^-1. Also, the biofilm of E. faecalis and S. aureus was greatly inhibited at 100 µg mL^-1 compared to E. coli and P. aeruginosa. The activity of α-amylase and α-glucosidase enzyme was inhibited at 100 µg mL^-1 demonstrating its antidiabetic potential. The larval and pupal development was delayed at 25 µg mL^-1 of Ws-ZnO NPs. A complete mortality (100%) was recorded at 25 µg mL^-1. Ws-ZnO NPs showed least LC₅₀ value (9.65 µg mL^-1) compared to the uncoated ZnO NPs (38.8 µg mL^-1) and leaf extract (13.06 µg mL^-1). Therefore, it is concluded that Ws-ZnO NPs are promising to be used as effective antimicrobials, antidiabetic and insecticides to combat storage pests.

Growth performance and hemato-immunological responses of Nile tilapia (Oreochromis niloticus) exposed to deltamethrin and fed immunobiotics

The use of feed additives in aquatic animals improves health conditions and well-being under pesticide toxicity. Thus, this study was aimed at evaluating the effect of an immunobiotic mixture (IM) on the growth performance, hemato-biochemistry, and immunity of Nile tilapia exposed to subacute deltamethrin (DMT). Fish were distributed into four groups: groups 1 and 2 were fed a control diet, while groups 3 and 4 were fed IM. Groups 2 and 4 were exposed to DMT (15 μg/L) in rearing water. The results revealed that DMT-exposed fish exhibited significantly lower final body weights, weight gain, specific growth rate, and survival rate (P < 0.05), while IM feeding resulted in improved growth performance and survival rate in fish with or without DMT toxicity. After 15 and 30 days, DMT-treated fish showed a significant increase in blood urea and bilirubin as well as hepatic enzymes (alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase) (P < 0.05), while supplementation of the IM mixture significantly lowered these levels in Nile tilapia. Blood total protein, globulin, albumin, white blood cells, red blood cells, hemoglobin, phagocytic index, and phagocytic and lysozyme activities were significantly decreased in tilapia subjected to DMT (P < 0.05), while supplementation of the IM mixture significantly increased these levels. Fish fed IM without DMT exposure showed the lowest cortisol and glucose levels, while fish exposed to DMT without IM showed the highest levels (P < 0.05) after 15 and 30 days. To conclude, IM supplementation exhibited defensive effects against DMT toxicity in Nile tilapia by improving growth performance, hematology, blood biochemistry, and immunity.

The effect of the antidepressant venlafaxine on gene expression of biotransformation enzymes in zebrafish (Danio rerio) embryos

The effect of venlafaxine, a pharmaceutical commonly found in aquatic environment, was analyzed on non-target organism, Danio rerio (Hamilton, 1822). D. rerio embryos were treated by two different concentrations of venlafaxine: either concentration relevant in aquatic environment (0.3 μg/L) or concentration that was two orders of magnitude higher (30 μg/L) for the evaluation of dose-dependent effect. Time-dependent effect was rated at 24, 96, and 144 h post-fertilization (hpf). For gene expression, genes representing one of the phases of xenobiotic biotransformation (0 to III) were selected. The results of this study showed that the effect of venlafaxine on the zebrafish embryos is the most evident at hatching (96 hpf). At this time, the results showed a downregulation of gene expression in each phase of biotransformation and in both tested concentrations. In contrast, an upregulation of most of the genes was observed 144 hpf for both tested venlafaxine concentrations. The study shows that venlafaxine can affect the gene expression of biotransformation enzymes in D. rerio embryos even in the environmentally relevant concentration and thus disrupt the process of biotransformation. Moreover, the pxr regulation of genes seems to be disrupted after venlafaxine exposure in dose- and time-dependent manner.