Exposure to low-concentration fipronil impairs survival, behavior, midgut morphology and physiology of Aedes aegypti larvae.

The Aedes aegypti mosquito is a vector for various arboviruses, including dengue and yellow fever. Insecticides, such as pyrethroids and organophosphates, are widely used to manage and control these insects. However, mosquitoes have developed resistance to these chemicals. Therefore, this study aimed to investigate the effects of the commercial formulation of fipronil (Tuit® Florestal; 80% purity) on the survival, behavior, morphology, and proteins related to signaling pathways of the midgut in A. aegypti larvae under controlled laboratory conditions. Significant reductions in immature survival were observed in all concentrations of fipronil tested. Low insecticide concentration (0.5 ppb) led to decreased locomotor activity in the larvae and caused disorganization of the epithelial tissue in the midgut. Moreover, exposure to the insecticide decreased the activity of detoxifying enzymes such as catalase, superoxide dismutase, and glutathione-S-transferase. On the other hand, the insecticide increased protein oxidation and nitric oxide levels. The detection of LC3, caspase-3, and JNK proteins, related to autophagy and apoptosis, increased after exposure. However, there was a decrease in the positive cells for ERK 1/2. Furthermore, the treatment with fipronil decreased the number of positive cells for the proteins FMRF, Prospero, PH3, Wg, Armadillo, Notch, and Delta, which are related to cell proliferation and differentiation. These findings demonstrate that even at low concentrations, fipronil exerts larvicidal effects on A. aegypti by affecting behavior and enzymatic detoxification, inducing protein oxidation, free radical generation, midgut damage and cell death, and inhibiting cell proliferation and differentiation. Thus, this insecticide may represent a viable alternative for controlling the spread of this vector.

Exposure to environmental pharmaceuticals affects the macromolecular composition of mussels digestive glands.

Human pharmaceuticals represent a major challenge in natural environment. A better knowledge on their mechanisms of action and adverse effects on cellular pathways is fundamental to predict long-term consequences for marine wildlife. The FTIRI Imaging (FTIRI) spectroscopy represents a vibrational technique allowing to map specific areas of non-homogeneous biological samples, providing a unique biochemical and ultrastructural fingerprint of the tissue. In this study, FTIRI technique has been applied, for the first time, to characterize (i) the chemical building blocks of digestive glands of Mytilus galloprovincialis, (ii) alterations and (iii) resilience of macromolecular composition, after a 14-days exposure to 0.5 µg/L of carbamazepine (CBZ), valsartan (VAL) and their mixture, followed by a 14-days recovery period. Spectral features of mussels digestive glands provided insights on composition and topographical distribution of main groups of biological macromolecules, such as proteins, lipids, and glycosylated compounds. Pharmaceuticals caused an increase in the total amount of protein and a significant decrease of lipids levels. Changes in macromolecular features reflected the modulation of specific molecular and biochemical pathways thus supporting our knowledge on mechanisms of action of such emerging pollutants. Overall, the applied approach could represent an added value within integrated strategies for the effects-based evaluation of environmental contaminants.

Proteotranscriptomic analyses of the midgut and Malpighian tubules after a sublethal concentration of Cry1Ab exposure on Spodoptera litura.

BACKGROUND: Cry1Ab has emerged as a bio-insecticide to control Spodoptera litura (Lepidoptera: Noctuidae). However, the sublethal effects of Cry1Ab on the physiological changes and molecular level of S. litura have not been well documented. Our aims in this study were to assess the sublethal effect of Cry1Ab on S. litura, including midgut and Malpighian tubules as targets. RESULTS: After sublethal Cry1Ab exposure, distinct histological alterations were mainly observed in the midgut. Furthermore, the results of comparative RNA sequencing and tandem mass tag-based proteomics showed that, in the midgut, most differential expression genes (DEGs) were up-regulated and significantly enriched in the serine protease activity pathway, and up-regulated differential expression proteins (DEPs) were mainly associated with the oxidative phosphorylation pathway, whereas the down-regulated involved in the ribosome pathways. In the Malpighian tubules, DEGs and DEPs were significantly enriched in the ribosome pathway. We proposed that ribosome may act as a universal target in energy metabolism with other pathways via the results of protein-protein interaction analysis. Further, by verification of the mRNA expression of some Cry protein receptor and detoxification genes after Cry1Ab treatment, it was suggested that the ribosomal proteins (RPs) possibly participate in influencing the Bt-resistance of S. litura larvae under sublethal Cry1Ab exposure. CONCLUSION: Under sublethal Cry1Ab exposure, the midgut of S. litura was damaged, and the proteotranscriptomic analysis elucidated that Cry1Ab disrupted the energy homeostasis of larvae. Furthermore, we emphasized the potential role of ribosomes in sublethal Cry1Ab exposure. © 2024 Society of Chemical Industry.

Proteotranscriptomic Integration analyses reveals new mechanistic insights regarding Bombyx mori fluorosis.

The commercial value of silkworms has been widely explored and the effects of fluoride exposure on silkworms' breeding and silk production cannot be ignored. Bombyx mori is a commonly used model to explore the mechanisms of fluorosis. In the present study, we analyzed the differences in physiological and biochemical indicators after exposing larva to NaF, then evaluated differential genes and proteins. Compared to control, larvae exposed to 600 mg L-1 NaF presented decreased bodyweight, damaged midgut tissue, and were accompanied by oxidative stress. The RNA-seq showed 1493 differentially expressed genes (574 upregulated and 919 downregulated). Meanwhile, the TMT detected 189 differentially expressed proteins (133 upregulated and 56 downregulated). The integrative analysis led to 4 upregulated and 9 downregulated genes and proteins. Finally, we hypothesized that fluoride exposure might affect the intestinal digestion of silkworms, inhibit the gene expression of detoxification enzymes and stimulate cellular immune responses. Our current findings provided new insights into insect fluorosis.

Minthostachys verticillata Griseb (Epling.) (Lamiaceae) essential oil orally administered modulates gastrointestinal immunological and oxidative parameters in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Minthostachys verticillata (Griseb.) Epling (Lamiaceae) is a plant used in folk medicine for digestive or respiratory disorders. In addition, it is incorporated as condiment, in foods, as beverage flavoring or mate. The ethnopharmacological interest of M. verticillata resides in its essential oil (EO). Part of group has demonstrated the immunomodulatory ability of EO giving this oil a biological potential not known until that moment and conducted studies to evaluate their possible application in diseases of veterinary interest. However, the immunomodulatory effects of EO administered orally have not been fully characterized. AIM OF THE STUDY: This study evaluated the impact of EO oral administration on gastrointestinal and immune health through measurement of immunological and oxidative parameters in mice. MATERIAL AND METHODS: The EO was extracted from the leaves, slender stems and flowers of M. verticillata by hydrodistillation and chemical analyzed by gas chromatography-mass spectrometry (GC-MS). Prior to in vivo study, the cytotoxic effect of EO was determined using the human colon carcinoma Caco-2 cell line. For in vivo study, three groups of male Balb/c mice (n = 3) were orally administered with saline solution (control group) and EO (5 or 10 mg/kg/day) during 10 consecutive days. Subsequently, histological and hematological parameters, cytokines production, oxidative markers and CD4+ and CD8+ T cells were evaluated. RESULTS: The chemical analysis of EO revealed the presence of a high content of monoterpenes, being the main pulegone (76.12%) and menthone (14.28%). The EO oral administration improved mice growth performance and modulated systemic adaptive immune response by increasing in the total leukocyte number. A high percentage of CD4+ T cells were observed whereas the number of CD8+ T cells was not altered. EO did not alter the morpho-physiology of intestine and improved total antioxidant capacity by decreasing MDA concentrations. In addition, EO decreased the IL-6 levels and increased in the IL-4 and IL-10 concentrations. CONCLUSION: Results indicate that M. verticillata EO modulate inflammatory and oxidative parameters constituting a natural alternative which could be applied to improve gastrointestinal and immune functionality in animals.

Determination of levetiracetam by GC-MS and effects of storage conditions and gastric digestive systems on drug samples.

Background: Epilepsy is a neurologic condition that is occurs globally and is associated with various degrees of seizures. Levetiracetam is an approved drug that is commonly used to treat seizures in juvenile epileptic patients. Accurate quantification of the drug's active compound and determining its stability in the stomach after oral administration are important tasks that must be performed. Results & methodology: Levetiracetam was extracted from drug samples and quantified by gas chromatography mass spectrometry using calibration standards. Stability of levetiracetam was studied under various storage conditions and in simulated gastric conditions. The calibration plot determined for levetiracetam showed good linearity with a coefficient of determination value of 0.9991. The limits of detection and quantification were found to be 0.004 and 0.014 µg·ml-1, respectively. The structural integrity of levetiracetam did not change within a 4-h period under the simulated gastric conditions, and no significant degradation was observed for the different storage temperatures tested. Discussion & conclusion: An accurate and sensitive quantitative method was developed for the determination of levetiracetam in drug samples. The stability of the drug active compound was monitored under various storage and gastric conditions. The levetiracetam content determined in the drug samples were within ±10% of the value stated on the drug labels.

Histopathology of Gastrointestinal Immune-related Adverse Events: A Practical Review for the Practicing Pathologist.

Immune checkpoint inhibitors target checkpoint proteins with the goal of reinvigorating the host immune system and thus restoring antitumor response. With the dramatic increase in the use of checkpoint inhibitors for cancer treatment, surgical pathologists have assumed a major role in predicting the therapeutic efficacy (score based on programmed cell death ligand 1 immunohistochemistry and mismatch repair protein loss) as well as diagnosing the complications associated with these medications. Immune-related adverse events (irAEs) manifest as histologic changes seen in both the upper and lower gastrointestinal tract, and when viewed in isolation, may be morphologically indistinguishable from a wide range of diseases including infections, celiac disease, and inflammatory bowel disease, among others. Evaluation of biopsies from both the upper and lower gastrointestinal tract can aid in the distinction of gastrointestinal irAEs from their mimics. In the liver, the histologic changes of hepatic irAEs overlap with de novo diseases associated with hepatitic and cholangitic patterns of injury. The diagnosis of irAEs requires communication and collaboration from the pathologist, oncologist, and gastroenterologist. This review provides a background framework and illustrates the histologic features and differential diagnosis of gastrointestinal and hepatic irAEs.

Exposure to copper sulfate impairs survival, post-embryonic midgut development and reproduction in Aedes aegypti.

Aedes aegypti is a vector of several global human viruses responsible for high human morbidity and mortality. The method to prevent the transmission of vector-borne viruses is mainly based on the control of the insect vector using insecticides. Among these chemicals, copper sulfate is a compound widely used in agriculture with the potential to be used as an alternative to control these insects. This study evaluated the effects of the exposure of A. aegypti larvae to copper sulfate on survival, midgut morphology, blood-feeding and fecundity. The exposure to CuSO4 decreased the survival of A. aegypti during the immature phase. Adults obtained from exposed larvae had their lifespan decreased at all tested concentrations. The exposure to CuSO4 impaired the development in the transition from larvae to pupae and from pupae to adult. The number of eggs laid by females developed from larvae treated with CuSO4 was significantly lower than in control. In addition, the egg hatching rates were also negatively affected. The midguts of treated larvae and pupae showed epithelial disorganization. The number of cleaved caspase-3 cells increased in the midgut of exposed pupae compared to control. Moreover, there was a reduction in proliferating cells in treated larvae and pupae compared to the control. In conclusion, the results reveal that CuSO4 exposure has insecticidal activity against A. aegypti, which may be related to the impairment of the midgut metamorphosis and reduced proliferation of stem cells, with the consequent impairment of female mosquito fertility and fecundity.

CircRNA75 and CircRNA72 Function as the Sponge of MicroRNA-200 to Suppress Coelomocyte Apoptosis Via Targeting Tollip in Apostichopus japonicus.

Circular RNAs (circRNAs) act as essential regulators in many biological processes, especially in mammalian immune response. Nonetheless, the functions and mechanisms of circRNAs in the invertebrate immune system are largely unclarified. In our previous work, 261 differentially expressed circRNAs potentially related to the development of Apostichopus japonicus skin ulceration syndrome (SUS), which is a major problem restricting the sea cucumber breeding industry, were identified by genome-wide screening. In this study, via miRanda analysis, both circRNA75 and circrRNA72 were shown to share the miR-200 binding site, a key microRNA in the SUS. The two circRNAs were verified to be increased significantly in LPS-exposed primary coelomocytes, similar to the results of circRNA-seq in sea cucumber under Vibrio splendidus-challenged conditions. A dual-luciferase assay indicated that both circRNA75 and circRNA72 could bind miR-200 in vivo, in which circRNA75 had four binding sites of miR-200 and only one for circRNA72. Furthermore, we found that miR-200 could bind the 3'-UTR of Toll interacting protein (Tollip) to negatively mediate the expression of Tollip. Silencing Tollip increased primary coelomocyte apoptosis. Consistently, inference of circRNA75 and circRNA72 could also downregulate Tollip expression, thereby increasing the apoptosis of primary coelomocytes, which could be blocked by miR-200 inhibitor treatment. Moreover, the rate of si-circRNA75-downregulated Tollip expression was higher than that of si-circRNA72 under an equivalent amount. CircRNA75 and circRNA72 suppressed coelomocyte apoptosis by sponging miR-200 to promote Tollip expression. The ability of circRNA to adsorb miRNA might be positively related to the number of binding sites for miRNA.

Selective digestive decontamination, a seemingly effective regimen with individual benefit or a flawed concept with population harm?

Selective digestive decontamination (SDD) regimens, variously constituted with topical antibiotic prophylaxis (TAP) and protocolized parenteral antibiotic prophylaxis (PPAP), appear highly effective for preventing ICU-acquired infections but only within randomized concurrent control trials (RCCT's). Confusingly, SDD is also a concept which, if true, implies population benefit. The SDD concept can finally be reified  in humans using the broad accumulated evidence base, including studies of TAP and PPAP that used non-concurrent controls (NCC), as a natural experiment. However, this test implicates overall population harm with higher event rates associated with SDD use within the ICU context.

Caffeine as a Factor Influencing the Functioning of the Human Body-Friend or Foe?

Nowadays, caffeine is one of the most commonly consumed substances, which presents in many plants and products. It has both positive and negative effects on the human body, and its activity concerns a variety of systems including the central nervous system, immune system, digestive system, respiratory system, urinary tract, etc. These effects are dependent on quantity, the type of product in which caffeine is contained, and also on the individual differences among people (sex, age, diet etc.). The main aim of this review was to collect, present, and analyze the available information including the latest discoveries on the impact of caffeine on human health and the functioning of human body systems, taking into account the role of caffeine in individual disease entities. We present both the positive and negative sides of caffeine consumption and the healing properties of this purine alkaloid in diseases such as asthma, Parkinson's disease, and others, not forgetting about the negative effects of excess caffeine (e.g., in people with hypertension, children, adolescents, and the elderly). In summary, we can conclude, however, that caffeine has a multi-directional influence on various organs of the human body, and because of its anti-oxidative properties, it was, and still is, an interesting topic for research studies including those aimed at developing new therapeutic strategies.

Solanum nigrum Extract and Solasonine Affected Hemolymph Metabolites and Ultrastructure of the Fat Body and the Midgut in Galleria mellonella.

Glycoalkaloids, secondary metabolites abundant in plants belonging to the Solanaceae family, may affect the physiology of insect pests. This paper presents original results dealing with the influence of a crude extract obtained from Solanum nigrum unripe berries and its main constituent, solasonine, on the physiology of Galleria mellonella (Lepidoptera) that can be used as an alternative bioinsecticide. G. mellonella IV instar larvae were treated with S. nigrum extract and solasonine at different concentrations. The effects of extract and solasonine were evaluated analyzing changes in carbohydrate and amino acid composition in hemolymph by RP-HPLC and in the ultrastructure of the fat body cells by TEM. Both extract and solasonine changed the level of hemolymph metabolites and the ultrastructure of the fat body and the midgut cells. In particular, the extract increased the erythritol level in the hemolymph compared to control, enlarged the intracellular space in fat body cells, and decreased cytoplasm and lipid droplets electron density. The solasonine, tested with three concentrations, caused the decrease of cytoplasm electron density in both fat body and midgut cells. Obtained results highlighted the disturbance of the midgut and the fat body due to glycoalkaloids and the potential role of hemolymph ingredients in its detoxification. These findings suggest a possible application of glycoalkaloids as a natural insecticide in the pest control of G. mellonella larvae.

Implications of long-term exposure of a Lymantria dispar L. population to pollution for the response of larval midgut proteases and acid phosphatases to chronic cadmium treatment.

Cadmium (Cd) presence in terrestrial ecosystems is a serious threat that requires continuous development of biomonitoring tools. Ideally, a suitable biomarker of exposure should respond to the toxicant consistently in different populations regardless of previous exposure to pollution. Here we considered the activities and isoform patterns of certain proteases and acid phosphatases (ACP) in the midgut of Lymantria dispar larvae as well as the integrated biomarker response (IBR) for application in Cd biomonitoring. We compared the responses of caterpillars originating from unpolluted and polluted localities after they had been chronically subjected to dietary Cd (50 and 100 µg Cd/g dry food). The population inhabiting the unpolluted forest was far more sensitive to Cd exposure as the activities of total proteases, trypsin (TRY) and leucine aminopeptidase (LAP) were mostly reduced while the activities of total and non-lysosomal ACP were increased. Non-lysosomal ACP activity was elevated in larvae from the contaminated site in response to the higher Cd concentration. Exposure to the metal resulted in numerous alterations in the pattern of enzyme isoforms, but the responses of the two populations were similar except that larvae from the polluted locality were more tolerant to the lower Cd concentration. Non-lysosomal ACP activity and the appearance of ACP isoforms 4 and 5 together with the IBR index are the most promising indicators of Cd presence, potentially applicable even in populations with a history of exposure to pollution. TRY and total ACP activities could be used to monitor populations at uncontaminated localities.

Effects of fluoranthene on digestive enzymes activity and relative growth rate of larvae of lepidopteran species, Lymantria dispar L. and Euproctis chrysorrhoea L.

Fluoranthene is one of the most abundant polycyclic aromatic hydrocarbon pollutants in the environment and it may accumulate in plant leaves which are the main food source for phytophagous insect species. The aim of this study was to establish the effects of dietary fluoranthene on specific activities of digestive enzymes and expression of their isoforms in the midgut, and the relative growth rates of Lymantria dispar and Euproctis chrysorrhoea larvae. Exposure to fluoranthene led to significantly decreased trypsin activity in the midgut of larvae of both species. Leucine aminopeptidase activity decreased significantly in the midgut of L. dispar larvae exposed to the lower concentration of fluoranthene, but that enzyme activity showed the opposite trend in E. chrysorrhoea larvae. There was no pollutant induced changes in lipase activity in L. dispar, while elevated enzyme activity was recorded in the midgut of E. chrysorrhoea larvae exposed to the lower concentration of fluoranthene. Different patterns of expression of enzyme isoforms were noticed. Relative growth rates of both species significantly decreased in fluoranthene treated larvae. These responses indicate to the significance of relationships between physiological changes and fitness-related traits in L. dispar and E. chrysorrhoea larvae affected by pollutant, and contribute to understanding the mechanisms of their adjustment to stressful conditions.

Behavioral and ultrastructural effects of novaluron on Aedes aegypti larvae.

Chitin synthesis inhibitors (CSI) are supposed to inhibit formation of chitin microfibrils in newly synthesized cuticle during molting process. Conversely, there has been comparatively few data on morphological effects of CSI on non-target insect organs. In this work, the effects of the CSI novaluron on behavior and midgut of A. aegypti were evaluated. Toxicity bioassays revealed that novaluron is toxic to A. aegypti larva with LC50 = 18.57 mg L-1 when exposed in aqueous solution for 24 h. Novaluron treated larvae were less active and spent more time resting compared to the control group. Histopathology showed that midguts of novaluron-treated larvae had cytoplasm vacuolization and damaged brush border. Cytotoxic effects in midguts of treated larvae induced necrosis, autophagy and damage to mitochondria. Despite being chitin synthesis inhibitor, novaluron did not induce alterations in the integument of A. aegypti larvae. Fluorescence microscopy revealed that the number of digestive cells were higher in novaluron-treated larvae than in control, in response to digestive cell apoptosis. The present study highlights the importance of novaluron against A. aegypti larvae by causing injuries to non-target organs, altering behaviors, inducing cell death and inhibiting cell proliferation.

Amelioration of immune and digestive system through weed supplemented feed against Aeromonas hydrophila in Clarias gariepinus.

Aquaculture is one of the important globally growing industries. It serves as an important food source of protein for human beings. With the expanding demand for the fish and their products it has become extremely important to improve the aquaculture practices. Aquaculture in India has witnessed huge mortalities caused by bacteria, viruses, fungi, nematodes etc. Aquatic weeds plants are harmful for aquaculture in many ways. Present study is aimed to overcome the disease caused by Aeromonas hydrophila (fish pathogenic bacteria) through feed supplementation of two aquatic weed plants (Azolla pinnata and Ceratophyllum demersum). The fish were divided into 6 groups: experimental groups (fish fed on supplementary feed at 5% and 2.5% concentration for individual plant and challenged with bacteria), positive control (fish fed on non-supplemented feed and challenged with bacteria) and negative control (fish fed on non-supplementary feed and not challenged with bacteria). It was observed that supplemented feed enhanced both cell mediated and humoral immunity in fish. Therefore, we advocate that feed formulated with incorporation of Azolla pinnata and Ceratophyllum demersum leaf powder at 5% and 2.5% could be used to prevent disease caused by A. hydrophila or can be used to enhance fish health by boosting its immune system. The results of this study also showed an improved digestibility in fish fed on supplemented feed.

Role of digestive protease enzymes and related genes in host plant adaptation of a polyphagous pest, Spodoptera frugiperda.

The evolutionary success of phytophagous insects depends on their ability to efficiently exploit plants as a source of energy for survival. Herbivorous insects largely depend on the efficiency, flexibility, and diversity of their digestive physiology and sophistication of their detoxification system to use chemically diverse host plants as food sources. The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a polyphagous pest of many commercially important crops. To elucidate the ability of this insect pest to adapt to host plant mechanisms, we evaluated the impact of primary (corn) and alternate (rice) host plants after 11 generations on gut digestive enzymatic activity and expression profiles of related genes. Results indicated that the total protease and class-specific trypsin- and chymotrypsin-like protease activity of S. frugiperda significantly differed among host plant treatments. The class-specific protease profiles greatly differed in S. frugiperda midguts upon larval exposure to different treatments with inhibitors compared with treatments without inhibitors. Similarly, the single and cumulative effects of the enzyme-specific inhibitors TLCK, TPCK, and E-64 significantly increased larval mortality and reduced larval growth/mass across different plant treatments. Furthermore, the quantitative reverse transcription polymerase chain reaction results revealed increased transcription of two trypsin (SfTry-3, SfTry-7) and one chymotrypsin gene (Sfchym-9), which indicated that they have roles in host plant adaptation. Knockdown of these genes resulted in significantly reduced mRNA expression levels of the trypsin genes. This was related to the increased mortality observed in treatments compared with the dsRED control. This result indicates possible roles of S. frugiperda gut digestive enzymes and related genes in host plant adaptation.

Occurrence and ecotoxicity of cytostatic drugs 5-fluorouracil and methotrexate in the freshwater unionid Elliptio complanata.

Municipal effluents continuously release cytostatic drugs with unknown consequences in aquatic organisms. The purpose of the study was to examine the sublethal toxicity of 2 commonly-found cytostatic drugs 5-fluouracile (5-FLU) and methotrexate (MTX) to endemic Elliptio complanata freshwater mussels. The mussels were exposed of each drugs at 0, 4, 20 and 100 µg/L for 96 h t 15 °C. After the exposure period, glutathione S-transferase (GST) and dehydrofolate reductase (DHFR) activities, DNA damage and lipid peroxidation (LPO) were determined. The drugs were detected in mussel tissues with no evidence of accumulation with either drugs. The drug 5-FLU gave a larger spectrum of effects than MTX such as increased DHFR, decreased LPO and DNA strand breaks (repair activity) suggesting that the mussels were metabolically hindered and reduced DNA repair activity. The drug MTX only increased DHFR activity in the gonad. Hence, the data suggest that these drugs are biologically active in freshwater mussels and based on the reported maximum levels of these drugs in municipal effluents, the observed effects are likely in sessile freshwater mussel species downstream urban sources of pollution.

Sub-chronic effects of AgNPs and AuNPs on Gammarus fossarum (Crustacea Amphipoda): From molecular to behavioural responses.

The aim of the present study was the assessment of the sub-chronic effects of silver (AgNPs) and gold nanoparticles (AuNPs) of 40 nm primary size either stabilised with citrate (CIT) or coated with polyethylene glycol (PEG) on the freshwater invertebrate Gammarus fossarum. Silver nitrate (AgNO3) was used as a positive control in order to study the contribution of silver ions potentially released from AgNPs on the observed effects. A multibiomarker approach was used to assess the long-term effects of AgNPs and AuNPs 40 nm on molecular, cellular, physiological and behavioural responses of G. fossarum. Specimen of G. fossarum were exposed for 15 days to 0.5 and 5 µgL-1 of CIT and PEG AgNPs and AuNPs 40 nm in the presence of food. A significant uptake of both Ag and Au was observed in exposed animals but was under the toxic threshold leading to mortality of G. fossarum. Silver nanoparticles (CIT-AgNPs and PEG-AgNPs 40 nm) led to an up-regulation of Na+K+ATPase gene expression. An up-regulation of Catalse and Chitinase gene expressions due to exposure to PEG-AgNPs 40 nm was also observed. Gold nanoparticles (CIT and PEG-AuNPs 40 nm) led to an increase of CuZnSOD gene expression. Furthermore, both AgNPs and AuNPs led to a more developed digestive lysosomal system indicating a general stress response in G. fossarum. Both AgNPs and AuNPs 40 nm significantly affected locomotor activity of G. fossarum while no effects were observed on haemolymphatic ions and ventilation.

Toxicity of gamma aluminium oxide nanoparticles in the Mediterranean mussel (Mytilus galloprovincialis): histopathological alterations and antioxidant responses in the gill and digestive gland.

PURPOSE: Accumulation of Gamma aluminium oxide nanoparticles γ-Al2O3 NPs significant impact on aquatic ecosystems. However, the toxicity of γ-Al2O3 NPs in aquatic organisms has been limited investigated. This study investigated histopathological changes and antioxidant responses induced by different concentrations of γ-Al2O3 NPs in Mytilus galloprovincialis. MATERIAL AND METHODS: In this study, mussels were exposed to different concentrations of 5 nm γ-Al2O3 NPs (0, 5, 20 and 40 mg/L) for 96 h under controlled laboratory conditions. Gill and digestive gland from mussels were assessed to histopathological (light microscopy, histopathological condition indices, digestive gland tubule types), SOD, CAT, GPx activities. RESULTS: Histopathological indices calculated higher, and significantly different in all exposure groups compared to the control group in gill and digestive gland (p < 0.05). Atrophic phase tubules proportion very high in 20 and 40 mg/L γ-Al2O3 NPs exposure groups. No significant changes in CAT activities in the gill and digestive gland (p > 0.05). Superoxide dismutase (SOD) activities significantly different (p ≤ 0.05) in the digestive gland from 20 mg/L γ-Al2O3 NPs exposures, and GPx activities significantly different (p < 0.05) in gill from 40 mg/L γ-Al2O3 NPs exposures. CONCLUSION: These results indicate that contamination of γ-Al2O3 NPs negatively affects the aquatic organism.