Oxidative stress biomarkers of exposure in the blood of cichlid species from a metal-contaminated river

Biochemistry biomarkers and metal levels as indicators of environmental pollution in Danio rerio exposed to the Sorocaba River (S.P.), Brazil

Metal contamination of the environment poses a significant threat to human health and can cause significant damage to aquatic ecosystems. Danio rerio was exposed to Sorocaba River water for 96 h from two different sites in summer (S) and winter (W). Concentrations of Al, Cd, Cu, Mn and Zn were determined in the exposure water and in sediment. At the end of the exposure, the concentrations of Al, Cu and Mn at the Ibiúna point (P1) and Mn at the Itupararanga point (P2) decreased compared to the initial concentrations in the water. In summer and winter, the highest concentrations of Cu and Mn were found in the sediment. Exposure to the Sorocaba River water caused various responses both in summer and winter. For example, GPx decreased in winter, Glutathione S-Transferase (GST) increased in summer, and Nitric Oxide Synthase (NOS) decreased in both seasons in the viscera. In winter, SOD Superoxide Dismutase (SOD) increased, while GPx and GST (winter) decreased in muscle; regarding viscera carbonyl proteins, there was an increase in the summer at P2. Acetylcholinesterase activity decreased in the brain in winter at P2 and NOS decreased in the summer-exposed groups and increased in the winter P2-exposed group. Lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) decreased in viscera (S, P1) and increased in muscle (S, P1 and P2). The glucose and triglycerides increased in muscle, both in summer and winter. Correlation analysis revealed associations between biomarkers from different organs. These alterations suggest that the fish experienced oxidative stress in response to exposure to the Sorocaba River, contaminated with metals, highlighting their vulnerability to environmental pollutants.

Glycated LDL generates reactive species that damage cell components, oxidize hemoglobin and alter surface morphology in human erythrocytes

Low-density lipoprotein (LDL) transports cholesterol to various tissues via the blood. Glycation of LDL occurs during hyperglycemic condition which is characterised by persistently high blood glucose level. Circulating erythrocytes can come in direct contact with glycated LDL (G-LDL). The objective of this study was to investigate the effect of G-LDL on human erythrocytes, specifically on hemoglobin, intracellular generation of reactive species and the antioxidant defence system. Isolated erythrocytes were incubated with G-LDL (3 and 6 mg/ml) and native LDL (6 mg/ml) at 37 °C for 24 h. Native LDL and G-LDL untreated erythrocytes were similarly incubated at 37 °C and served as control. G-LDL treatment increased hemolysis compared to control and native LDL-treated erythrocytes. Incubation of erythrocytes with G-LDL led to an increase in protein oxidation and lipid peroxidation while greatly decreasing the total sulfhydryl content. It also significantly enhanced hemoglobin oxidation, heme degradation, and the release of free iron moiety. Treatment with G-LDL led to an appreciable increase in the production of reactive oxygen and nitrogen species. The antioxidant power and activities of major antioxidant enzymes were drastically reduced, while critical membrane-bound enzymes were inhibited. The surface morphology of G-LDL-treated erythrocytes was altered leading to the formation of echinocytes. Importantly, treatment of erythrocytes with native LDL did not significantly affect the above-mentioned parameters and values were similar to the corresponding controls. Thus, G-LDL is cytotoxic to human erythrocytes and causes oxidative damage to cell components. This can reduce the oxygen-transporting ability of blood and also result in red cell senescence and anemia.

In vivo toxicological assessment of silver nanoparticle in edible fish, Oreochromis mossambicus

Silver nanoparticles are the extensively utilized among all nanoparticles due to their antibacterial and wound healing properties making them highly suitable for medical and pharmaceutical applications. The field of nanoparticle toxicity is an emerging field and the present study aims to assess the biochemical, hematological and genotoxicity in Oreochromis mossambicus exposed to different concentrations of silver nanoparticles for 7 and 14 days. Silver nanoparticles were synthesized by reduction of silver nitrate using trisodium citrate and was characterized using X-ray diffraction, SEM, HRTEM and DLS. Hematological parameters like RBC, WBC, Hb, HCT and MCV and for biochemical analysis, antioxidant enzymes SOD, CAT and GPX and serum enzymes AST, ALT, ACP, ALP and LDH were analyzed. Genotoxicity was studied using comet assay. Results obtained showed decrease in erythrocytes, HCT, Hb and MCV while an increase was noted in WBC on day 7 and 14. The antioxidant enzymes SOD, CAT and GPx showed a decrease and the lipid peroxidation product MDA was elevated. The serum enzymes AST, ALT, ACP ALP and LDH showed an increased activity when compared to control. DNA damage was evident by an increase in % TDNA. The results indicate hematological, biochemical and genotoxicity of silver nanoparticles that might be mediated through ROS generation in O. mossambicus.

Ameliorative effects of Dunaliella salina microalgae on nanoparticle (ZnO NPs)-induced toxicity in fish

Dunaliella salina (D. salina) is a well-known microalga that contains considerable amounts of nutritious and medicinal bioactive components. This work studied the modulatory role of D. salina against zinc oxide nanoparticle (ZnO NPs)-induced neurotoxic effects in adult zebrafish. Fishes were subjected to 0.69 mg L-1 (1/5th 96-h LC50) for 4 weeks; then, fishes were supplemented with D. salina in the diet for 2 weeks at two levels (15 and 30%). Exposure to ZnO NPs induced a significant increase in the levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OH-dG) while accompanied with downregulation of antioxidant genes in the brain of exposed fishes. Brain neurochemistry and enzyme activities were also altered following ZnO NP exposure. ZnO NPs significantly reduced the neurotransmitters and acetylcholinesterase (AchE) activity while increasing Alzheimer's disease-related proteins and inflammatory response via upregulation of tumor necrosis factor (TNF-α). Additionally, ZnO NPs increased the indices of brain's DNA oxidative damage, increasing brain tissue's metallothionein (MT) and zinc residues. ZnO NPs upregulated the transcription patterns of apoptosis-related genes (casp3 and p53). D. salina dietary co-supplementation with ZnO NPs alleviated the ZnO NPsZnO NP-induced neuro-oxidative damages by lowering the lipid, DNA damage, and inflammatory biomarkers. Besides, D. salina alleviating responses were linked with increasing the levels of the assessed antioxidants. Conclusively, D. salina dietary supplementation induced potential alleviating effects of the ZnO NP-induced neurotoxicity in adult zebrafish.

Seasonal assessment of selected trace elements in grass carp (Ctenopharyngodon idella) blood and their effects on the biochemistry and oxidative stress markers

Environmental pollution by anthropogenic activity is still a highly relevant global problem. Aquatic animals are a specifically endangered group of organisms due to their continuous direct contact with the contaminated environment. Concentrations of selected trace elements in the grass carp (Ctenopharyngodon idella) (n = 36) blood serum/clot were monitored. Possible effects of the elements on selected biochemical and oxidative markers were evaluated. The concentrations of trace elements (Al, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, Mn, Mo, Ni, Pb, Sr, Tl, and Zn) were analysed in the fish blood serum and blood clot by inductively coupled plasma optical emission spectrometry (ICP OES). A general scheme of decreasing concentrations of trace elements in the blood serum samples was: Zn ˃ Fe ˃ Sr ˃ Ba ˃ Ni ˃ Al ˃ Cu ˃ Be ˃ Co; < LOQ (below limit of quantification): Bi, Cd, Cr, Ga, Mn, Mo, Pb, Tl; and in the case of the blood clot, the scheme was as follows: Fe ˃ Zn ˃ Sr ˃ Al ˃ Ni ˃ Ba ˃ Cu ˃ Be ˃ Co ˃ Mn; < LOQ (below limit of quantification): Bi, Cd, Cr, Ga, Mo, Pb, Tl. Significant differences among the seasons were detected. The Spearman R correlation coefficients and linear or non-linear regression were used to evaluate direct relationships between trace elements and selected blood biomarkers. The correlation analysis between biochemical parameters (Na, K, P, Mg, AST, ALT, ALP, GGT, TAG, TP, urea, glucose) and trace elements (Al, Ba, Be, Cu, Fe, Ni, Sr, and Zn) concentrations confirmed statistically significant interactions in both seasons (summer and autumn). The regression analysis between oxidative stress markers (ROS, GPx, creatinine, uric acid, and bilirubin) and elements (Al, Ba, Co, Cu, Fe, Ni, and Sr) content confirmed statistically significant interactions. The results point to numerous connections between the observed elements and the physiological parameters of freshwater fish.

Toxic and bioaccumulative effects of zinc nanoparticle exposure to goldfish, Carassius auratus (Linnaeus, 1758)

The widespread use of produced metal oxide nanoparticles (NPs) has increased major concerns about their impact on human as well as aquatic animal health. The present study shows that exposure to different concentrations of zinc oxide (ZnO) NPs led to high accumulations of Zn ions in the metabolic organs of fish (liver and gills), resulting in severe oxidative stress in Carassius auratus. The goldfish (C. auratus) was chosen as an aquatic species for the evaluation of the potential toxicity of aqueous ZnO-NPs (Treatments of hemoglobin and neutrophils (0, 0.5, 1, and 1.5 mg L- 1) following 14 days of exposure. A range of histological and hematological factors were examined. Exposure to the NPs produced significant reduction of red blood cell and white blood cell counts, hematocrit) were found to produce no significant differences in lymphocyte, monocyte, and eosinophil counts; as well as the mean corpuscular hemoglobin concentrations index (P > 0.05). Moreover, the results revealed significant alterations in serum biochemical parameters, hepatic enzyme levels, and immune and antioxidant responses; except for total protein and superoxide dismutase (SOD) of C. auratus exposed to ZnO-NPs, particularly at the 1 and 1.5 mg L- 1 concentrations. Fish exposed to 1 and 1.5 mg L-1 ZnO-NPs displayed a significant reduction in alternative complement pathway activity, lysozyme, and total protein contents of mucus compared to those in the control group. The results showed that hepatic SOD and catalase, and gill catalase activity were significantly decreased, and their malondialdehyde levels increased at 1 and 1.5 mg L-1 ZnO-NPs compared to the control group (P < 0.05). Significant accumulations of ZnO-NPs were observed in the liver, kidney, and gill tissues of fish leading to severe histopathological alterations in these organs. These results suggest that water-borne ZnO-NPs can easily accumulate in metabolic organs and lead to oxidative stress and destructive effects on the physiological features of C. auratus.

Immunomodulation, Fish Health and Resistance to Staphylococcus aureus of Nile Tilapia (Oreochromis niloticus) Fed Diet Supplemented with Zinc Oxide Nanoparticles and Zinc Acetate

Recently some metal-based nanoparticles have gained serious attention from aquaculture and the fish feed industry as feed supplements. Oral supplementation of zinc oxide nanoparticles (ZnO-NPs) in fish feed, replacing Zn acetate (conventionally used zinc), is suggested as a cost-effective and efficient approach. Our study assessed the response of Nile tilapia, Oreochromis niloticus, fingerlings after its diet supplemented with chemically synthesized ZnO-NPs and zinc acetate under controlled conditions. ZnO-NPs were chemically synthesized and characterized. Tilapia fingerlings with an average body weight of 09.12 ± 1.23 g were randomly distributed into five groups. An 8-week trial was set with control and four experimental groups. Basal diet (D1) was used as control, whereas D2, D3 and D4 comprising 20, 40, and 60 mgkg-1 ZnO-NPs supplementation were experimental diets. Additionally, D5 was composed of a basal diet supplemented with 40 mgkg-1 of conventionally used zinc acetate. Significant improvement (P < 0.05) was found in nanoparticles and Zn acetate supplemented groups as compared to control, while the 40 mgkg-1 Zn-NPs supplemented diet (D3) showed best performance in terms of health parameters, oxidative status and disease resistance. Antioxidant profiling was based on catalase, superoxide dismutase, glutathione's transferase, and malondialdehyde; hematology included Hb, WBCs, RBCs, HCT MCV, MCH and MCHC; immunological parameters comprised IgM, lysozyme activity, phagocytic activity, respiratory burst activity, cholesterol, aspartate aminotransferase, alanine aminotransferase, glucose content, and total serum proteins. We report that the D3 (40 mgkg-1 ZnO-NPs supplementation) significantly (P < 0.05) improved health-related parameters as compared to the other groups. Moreover, D3 also showed significantly decreased mortality percentage when challenged by Staphylococcus aureus, while the Zn acetate supplemented diet group showed better results as compared to control. Overall results suggest the basal diet supplemented with 40 mgkg-1 ZnO-NP for enhanced health parameters, oxidative status, immune response, and disease resistance. Hence, 40mgkg-1 ZnO-NP can be recommended to formulate the practical diet of fish to boost health improvement, immunomodulation, and resistance to bacterial disease.

A review of chromium (Cr) epigenetic toxicity and health hazards

Carcinogenic metals affect a variety of cellular processes, causing oxidative stress and cancer. The widespread distribution of these metals caused by industrial, residential, agricultural, medical, and technical activities raises concern for adverse environmental and human health effects. Of these metals, chromium (Cr) and its derivatives, including Cr(VI)-induced, are of a public health concern as they cause DNA epigenetic alterations resulting in heritable changes in gene expression. Here, we review and discuss the role of Cr(VI) in epigenetic changes, including DNA methylation, histone modifications, micro-RNA changes, biomarkers of exposure and toxicity, and highlight prevention and intervention strategies to protect susceptible populations from exposure and adverse occupational health effects. Cr(VI) is a ubiquitous toxin linked to cardiovascular, developmental, neurological, and endocrine diseases as well as immunologic disorders and a high number of cancer types in humans following inhalation and skin contact. Cr alters DNA methylation levels as well as global and gene-specific histone posttranslational modifications, emphasizing the importance of considering epigenetics as a possible mechanism underlying Cr(VI) toxicity and cell-transforming ability. Our review shows that determining the levels of Cr(VI) in occupational workers is a crucial first step in shielding health problems, including cancer and other disorders. More clinical and preventative measures are therefore needed to better understand the toxicity and safeguard employees against cancer.

Biogenic Elements and Heavy Metals in Hermann's Tortoises-Testudo hermanni: Effect on Serum Biochemistry and Oxidative Status Parameters

BACKGROUND

Conservation of species diversity is the need of the hour for preserving life forms on Earth. Extinction of any part of the ecosystem has negative impacts on many processes and systems. The objective of this work was to analyze some biochemical and molecular indicators and their correlations to biogenic elements and heavy metals in Testudo hermanni (n = 16).

METHODS

Biochemical parameters were analyzed using the commercial kit DiaSys and biochemical analyzer Randox RX Monza. Sodium, potassium, and chlorides were measured using the EasyLite analyzer. Oxidative stress was evaluated using colorimetric and luminometric methods. Quantification of chemical elements in the blood was carried out using inductively coupled plasma mass spectrometry (ICPS).

RESULTS

Biochemical values of analyzed samples from Hermann's tortoises were almost the same as referential values described by multiple authors, with minor aberrations in the total protein parameter. Values of arsenic (As) and nickel (Ni) showed correlation with biochemical parameters and the parameters of oxidative stress. Cadmium (Cd) exhibited correlation with aspartate aminotransferase (AST).

CONCLUSIONS

This study reports correlations among four heavy metals, and their levels were again correlated with biochemical and molecular parameters in Hermann's tortoises.

Metalliferous atmospheric settleable particulate matter action on the fat snook fish (Centropomus parallelus): Metal bioaccumulation, antioxidant responses and histological changes in gills, hepatopancreas and kidneys

Metallic smoke released by steel industries is constitute by a mixture of fine and gross particles containing metals, including the emerging ones, which sedimentation contaminates soil and aquatic ecosystems and put in risk the resident biota. This study determined the metal/metalloids in the atmospheric settleable particulate matter (SePM, particles >10 μm) from a metallurgical industrial area and evaluated metal bioconcentration, antioxidant responses, oxidative stress, and the histopathology in the gills, hepatopancreas and kidneys of fat snook fish (Centropomus parallelus) exposed to different concentrations of SePM (0.0, 0.01, 0.1 and 1.0 g L^-1), for 96 h. From the 27 metals (Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Ag, Cd, Sn, Ba, La, Ce, W, Hg, Pb, Bi) analyzed, 18 were quantified in SePM and dissolved in seawater. Metal bioconcentrations differed among organs; Fe and Zn were the metals most bioconcentrated in all organs, Fe was higher in hepatopancreas and Zn > Fe > Sr > Al was higher in kidneys. The activity of superoxide dismutase (SOD) decreased in the gills; SOD, catalase (CAT) decreased, and glutathione peroxidase (GPx) increased in hepatopancreas and, CAT, glutathione-S-transferase (GST) and the level of glutathione (GSH) increased in kidneys. The unchanged levels of lipid peroxidation and oxidized protein in any organ indicate that the antioxidant responses were efficient to avoid oxidative stress. Organ lesion indices were higher in the gills > kidneys > hepatopancreas, being higher in fish exposed to 0.01 g L^-1 SePM. All changes indicate a tissue-specific metal/metalloids bioconcentration, antioxidant and morphological responses that all together compromise fish health. Regulatory normative are needed to control the emission of these metalliferous PM to preserve the environment and biota.

Effects of glyphosate, 2,4-D, chlorantraniliprole, and imidacloprid formulations, separately and in mixtures in Caiman latirostris hatchlings

The present study demonstrated the potential of glyphosate (GLY), 2,4-dichlorophenoxyacetic acid (2,4-D), imidacloprid (IMI) and chlorantraniliprole (CAP) separately and in mixtures to induce oxidative stress and DNA damage in Caiman latirostris hatchlings. Under controlled condition, an embryonic exposure to these pesticides was done at concentrations recommended for soybean crops. Treatments were: negative control, GLY, 2,4-D, IMI, CAP, mixture 1 (M1): GLY + 2,4-D, M2: IM I + CAP and M3: GLY + 2,4-D + IMI + CAP. At hatching, blood samples were taken for the evaluation of genotoxicity, oxidative damage to lipids and DNA, the enzymatic activity of Catalase (CAT) and Superoxide dismutase (SOD), and the expression level of their corresponding genes (catalase: cat and superoxide dismutase: sod). It has been shown that IMI, M2 and M3 induced a significant inhibition of CAT activity while no effect was observed on SOD. In turn, lipid peroxidation was significantly higher in individuals exposed to IMI, and to all the mixtures. Besides, genotoxicity and oxidative DNA damage were observed in all exposed groups. The results of mRNA expression showed no difference at transcription levels. In the same way, no alterations in growth parameters were recorded at hatching. Regarding to the mixtures, we observed a potentiating action of IMI on M3 in lipid peroxidation as well as independent action on oxidative DNA damage and genotoxicity parameters. Our results highlight the importance of investigating the effect of pesticides and their mixtures considering the potential consequences to caimans living in natural environments.

Protective effects of dietary supplementation of probiotic Bacillus licheniformis Dahb1 against ammonia induced immunotoxicity and oxidative stress in Oreochromis mossambicus

The goal of this study was to assess the efficacy of probiotics in mitigating ammonia-induced toxicity in fish. Fish were divided into four groups: control, only probiotic, only ammonia, and combined ammonia + probiotic. For 8 weeks, the Oreochromis mossambicus were exposed to waterborne ammonia at 1.0 mg L^-1 and/or dietary Bacillus licheniformis Dahb1 at 10⁷ cfu g^-1. After the 4^th and 8^th weeks, the fish were evaluated for growth performance, enzymatic and non-enzymatic antioxidant activities (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) reduced glutathione (GSH), neurotoxicity (acetylcholinesterase - AChE), non-specific immune responses (lysozyme (LYZ), myeloperoxidase (MPO), reactive nitrogen and oxygen species (RNS and ROS) and oxidative stress effects (lipid peroxidation (LPO), DNA damage)). Our results showed that in the absence of waterborne ammonia exposure, B. licheniformis Dahb1 significantly improved growth performance, enzymatic and non-enzymatic antioxidant capacity, AChE activity, non-specific immune response and decreased oxidative stress effect. Ammonia exposure resulted in significantly lower growth performance, reduced enzymatic and non-enzymatic antioxidant ability, decreased AChE activity, decreased non-specific immune response and increased oxidative stress effect. When O. mossambicus were exposed to ammonia, supplementation with B. licheniformis Dahb1 in the diet significantly increased survival, indicating that it may have a significant protective effect against ammonia toxicity by enhancing enzymatic and non-enzymatic antioxidant ability, activity of AChE, non-specific immune response and reduced oxidative stress effect. According to our findings, diet supplementation of B. licheniformis Dahb1 (10⁷ cfu g^-1) has the potential to combat ammonia toxicity in O. mossambicus.

Interference with zinc homeostasis and oxidative stress induction as probable mechanisms for cadmium-induced embryo-toxicity in zebrafish

The present study was conducted to provide new insights into the mechanisms that may be responsible for cadmium (Cd)-induced toxicity in zebrafish larvae as well as the role of the trace element zinc (Zn) in reversing Cd harmful effects. For this purpose, zebrafish eggs were exposed to Cd or/and Zn for 96 h. The effects on morphological aspect; mortality rate; Cd, Zn, and metallothionein (MT) levels; oxidative stress biomarkers; as well as molecular expression of some genes involved in Zn metabolism (Zn-MT, ZIP10, and ZnT1) and in antioxidant defense system (Cu/Zn-SOD, CAT and GPx) were examined. Our results showed that Cd toxicity was exerted, initially, by an interference with Zn metabolism. Thus, Cd was able to modify the expression of the corresponding genes so as to ensure its intracellular accumulation at the expense of Zn, causing its depletion. An oxidative stress was then generated, representing the second mode of Cd action which resulted in developmental anomalies and subsequently mortality. Interestingly, significant corrections have been noted following Zn supplementation based, essentially, on its ability to interact with the toxic metal. The increases of Zn bioavailability, the improvement of the oxidative status, as well as changes in Zn transporter expression profile are part of the protection mechanisms. The decrease of Cd-induced MTs after Zn supplement, both at the protein and the mRNA level, suggests that the protection provided by Zn is ensured through mechanisms not involving MT expression but which rather depend on the oxidative status.

Protective action of polysaccharides from Laurencia papillose (Rhodophyta) against imidacloprid induced genotoxicity and oxidative stress in male albino rats

Imidacloprid (IMI), the main component of neonicotinoid insecticides, promotes oxidative stress and genotoxicity in mammals. The aim of this experiment is to assess oxidative stress in liver cells and genotoxicity of erythrocytes for rats exposed to sub-lethal doses of IMI and the protective effects for Rhodophyta as antioxidant material versus imidacloprid. A total of 30 adult male albino rats (average body weight, 190–200 g) were divided into six groups (n=5) as follows: group 1 served as the control, group 2 received 200 mg/kg red algae, group 3 received 45 mg/kg IMI (high-dose group), group 4 received 22.5 mg/kg IMI (low-dose group), group 5 received 200 mg/kg red algae +45 mg/kg IMI, and group 6 received 200 mg/kg red algae +22.5 mg/kg IMI. After 28 d of treatment, the antioxidant activity of the crude extract of red algae was assessed in terms of free radical scavenging activity and found to be higher in TCA (75.57%) followed by DPPH (50.08%) at concentration 100 μg extract and a significant increase in lipid peroxidation and reductions in glutathione were observed in liver cells were intoxicated with high and low doses of IMI. Moreover decreases in catalase and glutathione peroxidase parameters in same previous groups which indicated oxidative stress. In addition significant increases in micronucleus frequency (MN) in the bone marrow of the rats as a genotoxicity marker which indicated DNA damage in erythrocytes cells with alterations in the histopathology of liver cells were also noted such as necrosis, inflammatory cells, infiltration, and necrobiotic changes. Whereas Rhodophyta succeeded in alleviation the oxidative damage and genotoxicity induced by the insecticide. In conclusion, IMI demonstrates hazardous effects, such as alterations in antioxidant status and mutagenicity of erythrocytes and polysaccharides from Rhodophyta has good antioxidant activity in vivo model systems against imidacloprid.

Growth Performance, Antioxidative Capacity, and Intestinal Histomorphology of Grey Mullet (Liza ramada)-Fed Dietary Zinc Nanoparticles

Zinc is one of the essential microelements involved in vital physiological and biological functions in the fish body. The study evaluated the growth performance, antioxidative capacity, and intestinal histomorphology of Grey Mullet (Liza ramada)-fed dietary zinc nanoparticles (ZnO-NPs) at 0, 10, 20, and 40 mg/kg for the first time. The final weight and specific growth rate (SGR) of Grey Mullet-fed dietary ZnO-NPs at 20 and 40 mg/kg were meaningfully enhanced (p < 0.05). Further, the weight gain (WG) was significantly higher in fish treated with ZnO-NPs than the control, and fish fed 20-40 mg/kg had the highest WG (p < 0.05). The feed conversion ratio (FCR) was meaningfully reduced in fish fed 20-40 mg ZnO-NPs/kg (p < 0.05). The histomorphology of the intestines revealed a significant improvement in villus height, villus width, and goblet cells by ZnO-NPs. The lysozyme activity, phagocytic activity, and phagocytic index showed higher levels in Grey Mullet-fed dietary ZnO-NPs at 20 mg/kg than fish fed 0, 10, and 40 mg/kg (p < 0.05). Superoxide dismutase (SOD) and catalase (CAT) were markedly improved in Grey Mullet treated with ZnO-NPs compared with the control, and the group of fish treated with 20 mg/kg had the highest SOD and CAT (p < 0.05). Glutathione peroxidase (GPx) was significantly higher in fish fed 20-40 mg/kg ZnO-NPs than fish fed 0-10 mg/kg and fish fed 40 mg ZnO-NPs/kg showing the highest GPx value (p < 0.05). The concentration of malondialdehyde was markedly lowered in Grey Mullet fed ZnO-NPs at varying levels (p < 0.05). Based on the overall results, the regression analysis suggests that ZnO-NPs can be included at 24.61-35.5 mg/kg for the best performances of Grey Mullet.

Neurotoxic, biotransformation, oxidative stress and genotoxic effects in Astyanax altiparanae (Teleostei, Characiformes) males exposed to environmentally relevant concentrations of diclofenac and/or caffeine

The present study evaluated neurotoxic, biotransformation, genotoxic and antioxidant responses to relevant environmental concentrations of diclofenac (0.4 μg L^-1) and caffeine (27.5 μg L^-1), separate and combined, in adult males of the freshwater fish Astyanax altiparanae after a subchronic exposure (14 days). Fish exposed to diclofenac and caffeine, both separate and combined, revealed a neurotoxic effect through the inhibition of acetylcholinesterase activity in the muscle, while diclofenac alone and in combination caused cyclooxygenase inhibition. Caffeine alone produces genotoxicity on this species but, when combined with diclofenac, it potentiates hepatic lipoperoxidation and the inhibition of oxidative stress enzymes, while diclofenac alone or in combination produces a general inhibition of important enzymes. This study suggests that aquatic contamination produced by these pharmaceuticals has the potential to affect homeostasis and locomotion in A. altiparanae and compromise their immune system and general health.

Ivermectin: A multilevel approach to evaluate effects in Prochilodus lineatus (Valenciennes, 1836) (Characiformes, Prochilodontidae), an inland fishery species

Ivermectin (IVM) is one of the most widely used antiparasitics worldwide. It is a potent and effective drug for treatment and prevention of internal and external parasitic infections of livestock and humans. IVM is excreted unchanged in manure of treated animals. Thus, residues of IVM may reach aquatic systems, affecting non-target organisms such as fish. Although the presence of IVM in aquatic environments has been reported, a multilevel approach (from cellular to behavioral responses) is necessary to determine the health of exposed organisms and the environmental risks associated. The aim of the present study was to investigate the response of the Neotropical fish Prochilodus lineatus, one of the main target species of South American freshwater fisheries, exposed to environmental concentrations of IVM: low (0.5 μg L^-1) and high (1.5 μg L^-1). Behavioral responses were assessed in juvenile fish and included water column use, routine swimming, total distance travelled, total activity time and Maximum swimming speed achieved during the escape response. Biochemical/oxidative stress responses assessed included brain acetylcholinesterase (AChE), catalase (CAT) and glutathione S-transferase (GST) activities; total antioxidant competence against peroxyl radicals (ACAP) and lipid oxidative damage (TBARs). Hematological biomarker responses included blood glucose levels, hematocrit, hemoglobin concentration, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and mean corpuscular volume. Condition factor and hepatosomatic index were also calculated. The lowest IVM concentration caused a significant decrease in GST activity and maximum swimming speed during the escape response. Multivariate analysis with biochemical/stress and behavioral data revealed overall effects of IVM treatments. This multilevel analysis shows detrimental effects related to swimming behavior and predator avoidance which could affect population size and size-structure of P. lineatus. To our knowledge this is the first attempt to assess the effects of IVM on Neotropical fishes using an integrative approach based on biomarkers from different levels of biological organization.

Interactive effects of freshwater acidification and selenium pollution on biochemical changes and neurotoxicity in Oreochromis mossambicus

Effect of selenium and acidification in freshwater environment was assessed solitary but no reports are available on the impacts of both factors act together. In the present study, effects of combined simultaneous exposure to selenium (Se) and low pH were assessed in Mozambique tilapia, Oreochromis mossambicus. Responses were measured based on antioxidant defenses (enzymatic SOD, CAT, GPx and non-enzymatic GSH), biotransformation enzyme (GST), metallothionein levels (MT), oxidative damage (LPO, CP), Na⁺/K⁺-ATPase (NKA) activity in gills and liver tissues and neurotoxicity (acetylcholinesterase, AChE) response in brain tissue. Fish were exposed to combined treatment at different pH levels (7.5, control (optimum pH for tilapia growth); 5.5, low pH) and Se concentrations (0, 10, and 100 μg L^-1). Toxicity levels of Se were not significantly different under control and low pH indicating that pH did not affect Se toxicity. Levels of GSH and MT were enhanced in Se-exposed fish at both pH. Combined effects of high Se concentration and low pH decreased SOD and CAT activities and increased those of GPx and GST. However, organisms were not able to prevent cellular damage (LPO and CP), indicating a condition of oxidative stress. Furthermore, inhibition of Na⁺/K⁺-ATPase activity was showed. Additionally, neurotoxicity effect was observed by inhibition of cholinesterase activity in organisms exposed to Se at both pH conditions. As a result, the combined stress of selenium and freshwater acidification has a slight impact on antioxidant defense mechanisms while significantly inhibiting cholinesterase and Na+/K + -ATPase activity in fish. The mechanisms of freshwater acidification mediating the toxic effects of trace non-metal element on freshwater fish need to investigate further.

Changes in weight gain, digestive and metabolic enzyme activities in Labeo rohita fingerlings in response to multiple stress exposure and dietary nutraceutical

A feeding trial was conducted for 4 months to study the effect of a nutraceutical conglomerate at different levels (0, 0.1, and 0.5%) on stress-exposed (high stocking density, H and feed restriction, R) Labeo rohita fingerlings. Six isonitrogenous diets with a crude protein of 35% were prepared for the different treatments, viz. THR0, THR1, THR5, TNS0, TNS1 and TNS5. Stress significantly reduced the weight gain and feeding of 0.1% nutraceutical improved it in both stress-exposed and non-exposed groups from 3 months onwards. Two-and three-month stress-exposed groups exhibited lower (p < 0.05) protease activity, while amylase activity was significantly higher in 2-month stress-exposed groups. Higher lipase activity was found in stress-exposed groups irrespective of the duration of stress. Higher serum glutathione peroxidase (GPx), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and hepatic and muscle lactate dehydrogenase (LDH) activities were observed in the THR0 groups; however, THR1 showed a lower activity of these enzymes. Increased malate dehydrogenase (MDH) and glucose-6-phosphate dehydrogenase (G6PDH) activity was recorded in the 1st and 2nd months stress-exposed groups. However, THR1 group exhibited a reduced MDH and G6PDH activity compared to THR0 group in 1st and 2nd months. Hence, it can be concluded that the duration of multiple stress exposure adversely affected the digestive and metabolic enzymes activities and feeding of 0.1% nutraceutical conglomerates could restore the activities of digestive and metabolic enzymes in rohu fingerlings.

Transcriptome sequencing provides insights into the mechanism of hypoxia adaption in bighead carp (Hypophthalmichthys nobilis)

Hypoxia negatively affects the behavior, immunology, physiology, and growth of fish. Therefore, uncovering the genetic mechanisms underlying hypoxia adaptation and tolerance in fish prior to any genetic improvement is essential. Bighead carp is one of the most important freshwater fish species in aquaculture worldwide; however, this species does not have a strong ability to tolerate hypoxia. In this study, the dissolved oxygen level (0.6 mg/L) was maintained above the asphyxiation point of bighead carp for a long time to simulate hypoxia stress. The liver, gills, and heart were sampled before (0 h) and after (1 h, 2 h, 4 h) the hypoxia tests. Glutathione peroxidase (GPx) and catalase (CAT) activities and malondialdehyde (MDA) levels in the liver were significantly (p < 0.05) elevated at 1 h after hypoxic stress. By observing tissue morphology, the cell structure of the liver and gill tissues was found to change to varying degrees before and after hypoxia stress. Transcriptome sequencing was performed on 36 samples of gill, liver, and heart at four time points, and a total of 293.55G of data was obtained. In the early phase (0-1 h), differentially expressed genes (DEGs, 807 genes upregulated, 654 genes downregulated) were mainly enriched in signal transduction, such as cytokine-cytokine receptor interactions and ECM-receptor interactions. In the middle phase (0-2 h), DEGs (1201 genes upregulated and 2036 genes downregulated) were mainly enriched in regulation and adaptation, such as the MAPK and FoxO signaling pathways. Finally, in the later phase (0-4 h), DEGs (3975 genes upregulated and 4412 genes downregulated) were mainly enriched in tolerance and apoptosis, such as the VEGF signaling pathway and apoptosis. The genes with the most remarkable upregulation at different time points in the three tissues had some similarities. Genetic differences in these genes may be responsible for the differences in hypoxia tolerance among individuals. Altogether, our study provides new insights into the molecular mechanisms of hypoxia adaptation in fish. Further, the key regulatory genes identified provide genetic resources for breeding hypoxia-tolerant bighead carp species.

Ecotoxicological evaluation of water from the Sorocaba River using an integrated analysis of biochemical and morphological biomarkers in bullfrog tadpoles, Lithobates catesbeianus ()

Lithobates catesbeianus tadpoles were exposed for 96 h to water from two sites of the Sorocaba River (summer and winter), Ibiúna (PI) and Itupararanga reservoir (PIR) that contained metals. In the liver, in PI, the glutathione peroxidase (GPx) decreased, and the glutathione S-transferase (GST) and carbonyl proteins (PCO) increased. In PIR, the glutathione reduced (GSH) increased, while there was a decrease in catalase (CAT), GPx, GST, PCO, and superoxide dismutase (SOD). In winter, GPx and GST increased in both points. Regarding the kidneys, lipoperoxidation (LPO) levels and GST decreased, while GSH increased in the summer. In the winter, LPO increased in PI. In the muscle, in the summer, there was an increase in GSH and GST and change in PCO. In the winter, the levels of PCO increased and CAT decreased in PIR. The area and volume of the hepatocyte and nucleus area increased in the summer and decreased in the winter. Hepatic melanin decreased in the summer after exposure to PIR water. There were the systemic effects of Sorocaba River water exposure at different times of the year with alterations in biomarkers at different levels, in which kidney shows highest Integrated Response of Biomarkers (IBR) value followed by liver and muscle. Biochemical biomarkers were more sensitive than morphological ones. The more sensitive biochemical markers were MT, PCO, GST and LPO. These effects confirm the hypothesis of metabolic alteration in bullfrog tadpoles by the Sorocaba River water.

H9c2(2-1)-based sulforhodamine B assay as a possible alternative in vitro platform to investigate effluent and metals toxicity on fish

To overcome restrictions on the use of fish in toxicity testing, the present study proposes to compare the 50% growth inhibition potential (EC₅₀) of four types of effluents on the rat cardiomyoblast H9c2(2-1) cell line by using the sulforhodamine B (SRB) cell mass colorimetric assay, with the corresponding fish lethal test results. Our objective was to evaluate if H9c2(2-1) cells shows comparable sensitivities, in both relative and absolute terms, to those provided by fish. In parallel, this study also compared the results of the chemical characterization with the legislation in force for environmental protection against effluent release into the receiving environment. Moreover, we tested the H9c2(2-1)-based SRB assays with the metals of concern found in the effluent samples. Both fish and cell assays showed the same toxicity rank for effluents: Metal > Oil > Municipal > Paper, and it should be stressed that the complementarity of using chemical and biological data represents a step forward to guarantee both environmental and human safety, since the chemical characterization showed a different toxicity rank: Metal > Municipal > Oil > Paper. Regarding metal elements, the short-term fish results showed a toxicity rank non-comparable with the rank obtained for cells. Nevertheless, the gathered results reveal the potentiality of the in vitro H9c2(2-1) platform as an alternative for fish lethal testing to assess, in absolute terms, the toxicity of effluents, particularly municipal effluents, and metals.

Vitamin D Supplementation Induces Cardiac Remodeling in Rats: Association with Thioredoxin-Interacting Protein and Thioredoxin

BACKGROUND

Vitamin D (VD) has been shown to play an important role in cardiac function. However, this vitamin exerts a biphasic "dose response" curve in cardiovascular pathophysiology and may cause deleterious effects, even in non-toxic doses. VD exerts its cellular functions by binding to VD receptor. Additionally, it was identified that the thioredoxin-interacting protein (TXNIP) expression is positively regulated by VD. TXNIP modulate different cell signaling pathways that may be important for cardiac remodeling.

OBJECTIVE

To evaluate whether VD supplementation lead to cardiac remodeling and if TXNIP and thioredoxin (Trx) proteins are associated with the process.

METHODS

A total of 250 Male Wistar rats were allocated into three groups: control (C, n=21), with no VD supplementation; VD3 (n = 22) and VD10 (n=21), supplemented with 3,000 and 10,000 IU of VD/ kg of chow respectively, for two months. The groups were compared by one-way analysis of variance (ANOVA) and Holm-Sidak post hoc analysis, (variables with normal distribution), or by Kruskal-Wallis test and Dunn's test post hoc analysis. The significance level for all tests was 5%.

RESULTS

TXNIP protein expression was higher and Trx activity was lower in VD10. The animals supplemented with VD showed increased lipid hydroperoxide and decreased superoxide dismutase and glutathione peroxidase. The protein Bcl-2 was lower in VD10. There was a decrease in fatty acid β-oxidation, tricarboxylic acid cycle and electron transport chain with shift to increase in glycolytic pathway.

CONCLUSION

VD supplementation led to cardiac remodeling and this process may be modulated by TXNIP and Trx proteins and consequently oxidative stress.

Bioallethrin enhances generation of ROS, damages DNA, impairs the redox system and causes mitochondrial dysfunction in human lymphocytes

Bioallethrin is a synthetic pesticide that is widely used to control insect pests. The wide use of bioallethrin has resulted in inevitable human exposure. In this study we report the effect of different concentrations of bioallethrin (10 to 200 µM, 2 h at 37 °C) on human lymphocytes under in vitro conditions. Bioallethrin treatment resulted in loss of cell viability (> 30% at 200 µM bioallethrin). Oxidative stress markers like lipid peroxidation and protein oxidation were significantly increased accompanied by lower ratio of reduced to oxidized glutathione. Enhanced ROS generation was observed through fluorescence spectroscopy and microscopy. Bioallethrin-induced oxidative stress also compromised the antioxidant defence as it reduced antioxidant capacity of cells and inhibited major antioxidant enzymes. Biomolecular modifications and systemic toxicity by bioallethrin resulted in plasma membrane damage with mitochondrial depolarization. Comet assay showed nuclear DNA fragmentation and strand scission with significant increase in tail length and olive tail moment. Apoptosis and necrosis of cells was confirmed through acridine orange/ethidium bromide dual staining and visualization under fluorescence microscope. Thus, bioallethrin causes oxidative damage and compromises the antioxidant system leading to DNA damage, cellular and organelle toxicity, resulting in apoptosis and necrosis of human lymphocytes.

Study on the impacts of chemical and green synthesized (Leucas aspera and oxy-cyclodextrin complex) dietary zinc oxide nanoparticles in Nile tilapia (Oreochromis niloticus)

The present study was designed to evaluate the health effects of dietary nanozinc prepared by two methods: conventional chemical method and green method. The parameters evaluated were the extent of bioaccumulation, antioxidant status, histological, immunological changes and DNA damage in Nile tilapia fed nanozinc feed. Zinc oxide nanoparticles were first prepared by green and chemical methods. Before feed preparation, the in vitro antioxidant activity and antibacterial activity of both types of nanoparticle solutions were tested and the results revealed enhanced activities in green synthesized ZnO NP solution. After the acclimatization period, 420 Nile tilapias were distributed randomly into 21 glass tanks with 20 fish per tank in triplicates. Fish were fed control diet without any ZnO NP and (i) GT1-green synthesized ZnO NP diet at 100 mg/kg, (ii) CT1-chemically synthesized ZnO NP diet at 100 mg/kg, (iii) GT2-green synthesized ZnO NP diet at 200 mg/kg, (iv) CT2-chemically synthesized ZnO NP diet at 200 mg/kg, (v) GT3-green synthesized ZnO NP diet at 400 mg/kg and (vi) CT3-chemically synthesized ZnO NP diet at 400 mg/kg for 60 days. After 60 days, gill and liver samples were collected for analysing oxidative stress, histopathological alterations and bioaccumulation of zinc, whereas serum samples were collected for evaluating immune response. The results revealed that the GT3 diet significantly (P < 0.05) enhanced the level of antioxidant enzymes (CAT, SOD, GPx, GR and GSH) than dietary nanozinc prepared by the chemical method. Similarly, the innate immunological parameters were significantly (P < 0.05) augmented in fish fed GT3 diet. Comparative histological study of liver and gill tissues revealed normal architecture in the tissues of fish fed green synthesized NP-enriched feed, whereas the tissues of fish fed chemically synthesized NP feed exhibited histological alterations. Bioaccumulation of zinc was more in the liver followed by the muscle and least in the gills and DNA damage was more evident in fish fed chemically synthesized ZnO NP-enriched feed. In conclusion, the results suggest that the inclusion of 400 mg/kg GT3 diet in fish diet enhanced the level of antioxidant enzymes, boosted immune response and did not cause histological damage to organs, and therefore, GT3 nanofeed can be recommended for fish health improvement.

Essential oil of Ocimum gratissimum (Linnaeus, 1753): efficacy for anesthesia and transport of Oreochromis niloticus

This study aimed to evaluate the essential oil of Ocimum gratissimum L. (EOOG) for anesthesia and in the transport of Oreochromis niloticus. Experiment I determined the time of anesthesia induction and recovery during anesthesia of O. niloticus exposed to different concentrations of EOOG (0, 30, 90, 150, and 300 mg L^-1). Based on data from Experiment I, Experiment II evaluated the effect of 0, 30, and 90 mg L^-1 EOOG on blood parameters and oxidative stress immediately after anesthesia induction and 1 h after recovery. Experiment III evaluated the effect of 0, 5, and 10 mg L^-1 EOOG on blood variables immediately after 4.5 h of transport of juveniles. Concentrations between 90 and 150 mg L^-1 EOOG were efficient for anesthesia and recovery. The use of 90 mg L^-1 of EOOG prevented an increase in plasma glucose. Other changes in blood parameters and oxidative stress are discussed. The use of 10 mg L^-1 EOOG in transport increased plasma glucose and decreased hematocrit values immediately after transport. It is concluded that the use of 90 and 150 mg L^-1 EOOG causes anesthesia and recovery in O. niloticus within the time intervals considered ideal. The use of 90 mg L^-1 EOOG favored stable plasma glucose soon after anesthesia induction and 1 h after recovery, but caused changes in the antioxidant defense system by increasing hepatic and kidney ROS. The transport of 12 g O. niloticus for 4.5 h can be performed with concentration of 5 mg L^-1 of EOOG.

The neurophysiological effects of iron in early life stages of zebrafish

Trace metal/ion homeostasis, neurophysiological performance, and molecular responses to iron (Fe) exposure were investigated in the model organism zebrafish (Danio rerio). The findings demonstrated that exposure to a sublethal concentration of ferric iron (Fe³⁺) increased Fe contents in both the whole body and head region of developing zebrafish. Among the various trace metals and major ion examined, a dysregulation in manganese, zinc, nickel, and calcium balance was also observed in Fe-exposed larvae. Further biochemical assay and in-vivo imaging revealed that Fe exposure resulted in possible oxidative stress-induced damage, and an increased generation of reactive oxygen species in specific regions of the larvae. Using a droplet digital PCR (ddPCR) technology, it was found that the expression levels of various oxidative stress-responsive genes were temporally modulated by Fe exposure. Additionally, Fe-exposed larvae exhibited an impairment in escape response and a decrease in swimming activity. These larvae also appeared to exhibit a reduced anxiety-like behaviour. Together, our research suggested that larvae experiencing an increased Fe loading exhibited a dysregulation in metal homeostasis and a decrease in neurophysiological performance. These results suggested that neurophysiological assessments are sensitive methods to evaluate Fe toxicity in developing fish.

DHF-BAHPC molecule exerts ameliorative antioxidant status and reduced cadmium-induced toxicity in zebrafish (Danio rerio) embryos

In this study, we report the antioxidant and antitoxic potential of chemically synthesized 4-oxo-2-phenyl-4H-chromene-7,8-diyl bis((1-amino-2-hydroxypropyl)carbamate) (DHF-BAHPC) compound using in vitro and in vivo assays. The DHF-BAHPC was synthesized by linking 7,8-Dihydroxyflavone (DHF) with two molecules of Fmoc-threonine and characterized by Ultraviolet-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FT-IR), ¹H NMR, ¹³C NMR and Mass spectrometry (MS). In vitro, antioxidant assay results revealed that DHF-BAHPC has a dose-dependent radical scavenging potential towards DPPH, ABTS, FRAP and H₂O₂ radicals with an IC₅₀ range of 15.45, 66.27, 25.71, 4.375 μg/mL, respectively. Furthermore DHF-BAHPC treatment significantly altered cadmium (Cd) intoxicated zebrafish embryos by rescuing the developmental changes associated with severe histological and reduced the level of defensive antioxidant activities (SOD, CAT, GPx and GST). The overall results of the present study represented that DHF-BAHPC may be used as a potential drug in redox-based therapeutics.

Biomarkers of the oxidative stress and neurotoxicity in tissues of the bullfrog, Lithobates catesbeianus to assess exposure to metals

Lithobates catesbeianus tadpoles were exposed to 1 μg L^-1 of zinc (Zn), copper (Cu) and cadmium (Cd) alone or combined (1:1 and 1:1:1) for 2 and 16 days. Results showed a significant increase in the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities in the liver, kidney and muscle (except for GPx) in the groups exposed to metal either alone or co-exposed after 2 days compared to the control. After 16 days, SOD, CAT and GST activities decreased significantly in the liver and kidney and GPx activity increased in the liver. Reduced glutathione (GSH) increased in the liver and kidney following combined exposure and decreased after 2 days of metal exposure in the muscle. There were significant increases in lipid hydroperoxide (LPO) levels in the liver, kidney and muscle (2 and 16 days), with the highest levels after metal co-exposure. Cholinesterase (ChE) activity increased significantly in the brain after 2 days of exposure but decreased in the brain (16 days) and muscle (2 days) after exposure to metals, alone and combined. The current study highlighted that the antioxidant system of L. catesbeianus was sensitive to metals and specially to the co-exposure of the three metals, despite presenting differences in the response among tissues. In addition, tadpoles were sensitive at both periods of exposure, but in different modes with stress response (activation, up-regulation) at 2 days and oppression (down-regulation) at 16 days.

Banded tetra (Astyanax aeneus) as bioindicator of trace metals in aquatic ecosystems of the Yucatan Peninsula, Mexico: Experimental biomarkers validation and wild populations biomonitoring

Bioindicator organisms are important tools in environmental monitoring studies. Understanding this, the overall goal of the present study was to evaluate the sensitivity and viability of the native fish species Banded tetra, (Astyanax aeneus; Günther, 1860), widely spread in the aquatic ecosystems of the Yucatan Peninsula in Mexico, as a bioindicator organism. In order to do this, we performed a bioassay at sublethal concentrations using copper (CuSO₄) to experimentally evaluate and validate the relationship between the trace metals and oxidative stress biomarkers response [(catalase (CAT), lipoperoxidation content (LPO)], detoxification [(glutathione S-transferase (GST), metallothionein content (MT)] and neurotoxicity (AChE) in muscle of A. aeneus. Results showed changes in biomarkers after 96 h: Catalase activity (CAT) was significantly higher above 1.5 and 2 mg/L (154.35 and 172.50% increase, respectively); lipid peroxidation contents (TBARS), GST activity, and MT content were very similar to CAT activity at 1.5 and 2 mg/L of Cu. In terms of neurotoxicity, AChE activity was significantly inhibited at 0.1 mg/L (64%; p < 0.001) and 0.5 mg/L (44%; p < 0.001) of Cu. Based on the bioassay results, we performed a trace metal monitoring campaign in muscle of A. aeneus caught in 15 sites with different anthropogenic activities, during the summer of 2017, to establish a baseline of trace metals pollution in the state of Campeche. A. aeneus showed the highest trace metal accumulation in the following order: Al > Fe > Mn > Zn > Cu > Hg > Cr > Pb > Cd > V > As, while sites were arrange as follows: Xnoha lagoon > Palizada River > Candelaria River > Ululmal > Maravillas > López Mateos. PCA showed a cluster between biomarkers (GST, CAT, TBARS, and MT) and concentration of metals (Cd, Cu, Fe, Zn, Hg and Cr). Conversely, AChE inhibition was not related to a specific metal, but highest inhibitions (>50%) were present in those sites with intensive agricultural practices. These results determined that, based on its physiological response and trace metal bioaccumulation, Astyanax aeneus can be considered a good bioindicator for evaluating the presence of trace metals in tropical aquatic systems of the Yucatan Peninsula.

Effects of seawater acidification and cadmium on the antioxidant defense of flounder Paralichthys olivaceus larvae

Increasing atmospheric carbon dioxide has led to a decrease in the pH of the ocean, which influences the speciation of heavy metals and consequently affects metal toxicity in marine organisms. To investigate the effects of seawater acidification and metals on the antioxidant defenses of marine fishes, the flounder Paralichthys olivaceus, was continuously exposed to cadmium (Cd; control, 0.01 and 0.15 mg L^-1) and acidified seawater (control (pH 8.10), 7.70 and 7.30) for 49 days from embryogenesis to settlement. The results demonstrated that both Cd and acidified seawater could induce oxidative stress and consequently cause lipid peroxidation (LPO) in the larvae. Antioxidants (i.e., superoxide dismutase, SOD; catalase, CAT; reduced glutathione, GSH; glutathione S-transferase, GST; glutathione peroxidase, GPx; and glutathione reductase, GR) functioned to defend the larvae against oxidative damage. Overall, Cd induced (SOD, GST and GSH) or inhibited (CAT and GPx) the enzymatic activities or contents of all the selected antioxidants except for GR. The antioxidants responded differently to seawater acidification, depending on their interaction with the metal. Similarly, the mRNA expressions of the antioxidant-related genes were upregulated (sod, gr and gst) or downregulated (cat and gpx) in response to increasing Cd exposure. Seawater acidification did not necessarily affect all of the biomarkers; in some cases (e.g., SOD and sod, GR and gr), Cd stress may have exceeded and masked the stress from seawater acidification in regulating the antioxidant defense of the larvae. The integrated biomarker response (IBR) was enhanced with increasing levels of the stressors. These findings support the hypothesis that seawater acidification not only directly affects the antioxidant defense in flounder larvae but also interacts with Cd to further regulate this defense. This study has ecological significance for assessing the long-term impacts of ocean acidification and metal pollution on the recruitment of fish populations in the wild.

Monitoring Bioaccumulation (in Gills and Muscle Tissues), Hematology, and Genotoxic Alteration in Ctenopharyngodon idella Exposed to Selected Heavy Metals

Health and environmental problems arising from metals present in the aquatic ecosystem are very well known. The present study investigated toxicological effects of LC₁₅ of metals such as copper, chromium, and lead for 24, 48, 72, and 96 h on hematological indices, RBC nucleus and cell morphology, and gill and muscle tissues of grass carp (Ctenopharyngodon idella). Experimental dose concentrations of copper were 1.5, 1.4, 1.2, and 1 mgL⁻¹. Similarly, dose concentrations of chromium were 25.5, 22.5, 20, and 18 mgL⁻¹ while those of lead were 250, 235, 225, and 216 mgL⁻¹, respectively. Maximum decrease in the concentration of Hb, RBCs, and monocytes was observed against chromium, while maximum increase in the concentration of lymphocytes was reported against lead. Abnormalities such as single and double micronuclei, deformed nucleus, nuclear shift, irregular nucleus, deformed cells, microcyte cells, and vacuolated and swollen cells were observed. Gill tissues absorbed maximum concentration of lead followed by chromium and copper. Muscle tissues also absorbed maximum concentration of lead followed by chromium and copper, respectively. Histological alterations such as epithelial lifting, interlamellar spaces, club gill filaments, gill bridging, curling filaments, swelling and fusion of cells, irregular cells, destruction of epithelial cells, cellular necrosis, and inflammatory cells were observed in gill tissues while inflammation and necrosis of muscle fibers, degeneration of muscle fibers, edema of muscle bundles, zig-zag of muscle fibers, and lesions were observed in muscle tissues of fish exposed with different doses of these heavy metals, indicating the toxicity of metals to aquatic fauna as well as to human being via food chain.

Fluctuation of biochemical, immunological, and antioxidant biomarkers in the blood of beluga (Huso huso) under effect of dietary ZnO and chitosan-ZnO NPs

The objective of the present study was to investigate the effects of dietary supplementation with zinc oxide (ZnO) and chitosan-zinc nanoparticles (chitosan-ZnO NPs) on biochemical, immunological, and antioxidant biomarkers in blood of juvenile belugas (Huso huso). The beluga juveniles with initial weight of 287 ± 46 g were fed with eight experimental diets containing 0 g kg^-1 ZnO (the control diet); 10, 20, and 40 mg kg^-1 ZnO; and 10, 20, and 40 mg kg^-1 chitosan-ZnO NPs and 36 mg kg^-1 chitosan. After 28 days of culture, the fish were fed with ZnO and chitosan-ZnO NP-supplemented diets showed a more significant increase in total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPX), and glutathione S-transferase (GST) activity (p < 0.05) compared to the control group. There were no significant differences (p > 0.05) in malondialdehyde (MDA) and glucose level in all treatment groups. The results showed that with increasing levels of ZnO and chitosan-ZnO NPs, alternative complement activity (ACH50), and total immunoglobulin, total protein, albumin, and lysozyme had a significant increase in fish fed with ZnO and chitosan-ZnO NP-supplemented diets compared to the control group (p < 0.05). ALP, ALT, and AST enzyme activities showed significant difference between control and treatment groups (p > 0.05), while the levels of LDH enzyme activity, urea, and creatinine decreased by increasing both ZnO and chitosan-ZnO NP levels. These results demonstrated that dietary chitosan-ZnO NPs could improve the health status, immune function, and antioxidant capacity of the cultured beluga juvenile.

Bioallethrin-induced generation of reactive species and oxidative damage in isolated human erythrocytes

Bioallethrin is an insecticide that is widely used to control mosquitoes, fleas and cockroaches. The widespread use of bioallethrin has resulted in both occupational and non-occupational human exposure. Bioallethrin enters blood, regardless of the route of exposure, where it can interact with erythrocytes. We have studied the effect of bioallethrin on isolated human erythrocytes under in vitro conditions. Erythrocytes were incubated with increasing concentrations of bioallethrin (10-200 μM) for 4 h at 37 °C. Several biochemical parameters were analyzed in bioallethrin treated and untreated (control) cells. Incubation of erythrocytes with bioallethrin increased protein oxidation, lipid peroxidation and depleted sulfhydryl group content. Membrane damage was evident from cell lysis, osmotic fragility, inhibition of bound enzymes and transmembrane electron transport system. Bioallethrin also increased hemoglobin oxidation, heme degradation and the release of free iron moiety. This will decrease the oxygen transporting ability of blood. Bioallethrin treatment altered the specific activities of antioxidant enzymes and diminished the antioxidant power of cells. Scanning electron microscopy showed that bioallethrin treatment also altered erythrocyte mophology. Almost all changes were in a bioallethrin concentration dependent manner. The cytotoxicity of bioallethrin is probably mediated by reactive oxygen and nitrogen species whose formation was significantly enhanced in treated erythrocytes. Thus bioallethrin enhances the generation of reactive species which cause oxidative damage of cell components in human erythrocytes.

Biochemical and molecular changes mediated by plasticizer diethyl phthalate in Chironomus circumdatus (bloodworms)

Plasticizers are used as additives in making plastics. Diethyl phthalate (DEP) is one of the majorly used plasticizers in various products. When plastic materials are dumped in an aquatic system, there is an increase in chances of DEP leaching out and getting deposited in water. Thus the current work focuses on studying the effect of DEP on the larval stages of Chironomus circumdatus. In this study it was found that there was an increase in lipid peroxidation levels indicating imposition of oxidative stress on these larvae due to the exposure of DEP. Changes in the levels of carbohydrates and lipids were also seen. To reduce these effects antioxidant defense system may get activated. Thus investigations showed an increase in enzymatic activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and acetylcholinesterases (AchE) and decrease in the activity of glutathione reductase (GR). Nonenzymatic antioxidant glutathione levels were also increased during the post-recovery exposure period. Thus this indicates that both enzymatic, as well as non-enzymatic antioxidants, play a certain role in reducing the stress mediated by DEP. Up-regulation of gene expression of heat shock protein70 (hsp70) was observed, which is one of the conserved protein produced during stress response in many dipterans. Changes in the level of expression of the ecdysone receptor (EcR) gene were also seen in DEP exposed larvae. Thus the insights give us a preliminary indication that physiological and developmental adaptations may take place in these organisms to persist in the DEP contaminated environment. CAPSULE: DEP mediated stress imposes changes in the metabolites and thus activation of antioxidant defense system in aquatic midges of Chironomus circumdatus. Changes in the expression of heat shock protein70 and ecdysone receptor was also seen indicating that DEP mediated stress affects at the molecular level also of the organism. These changes may help them to tolerate and live in DEP polluted water.

Impact of pyrethroids and organochlorine pesticides residue on IGF-1 and CYP1A genes expression and muscle protein patterns of cultured Mugil capito

This study aimed to assess the levels of pyrethroids and organochlorine residues in the tissues of cultured Mugil capito and in water samples obtained from three different sites (Al-Hamol, Al-Riad and Sidi Salem; referred to as Area 1, Area 2, and Area 3, respectively) in the Delta region, Egypt. The study also assessed the biochemical markers in exposed mullet and evaluated the impact of these residues on the expression of insulin-like growth factor 1 (IGF-1) in muscle and cytochrome P4501A (CYP1A) in liver tissues using qRT-PCR and SDS-PAGE methods. The results revealed that pesticide residue levels in the water were variable, but were lower than detected levels in fish. Significant (P < 0.05) differences were found across the three study areas in terms of serum ALT, but the serum AST level was not significantly (P > 0.05) elevated in all study regions. Serum creatinine and urea levels were significantly (P < 0.05) elevated in area 3. Furthermore, glutathione and malondialdehyde concentrations significantly increased (P < 0.05) in liver tissues in area 3. Using the qRT-PCR technique, the results revealed that the expression level of IGF-1 was most significant in area 3, while the expression level of CYP1A was most significant in area 1. The protein profile showed some differences in band numbers and molecular weights of protein bands across different regions. Overall, the alteration in biochemical parameters revealed pesticide interference with the metabolic processes of fish. Furthermore, the pesticide pollution had an effect on the expression of IGF-1 and CYP1A genes and led to changes in the protein profile. Therefore, these markers can be used to monitor fish distress following exposure to the pollutant.

Evaluation of Erythrocyte Morphometric Indices in Juvenile Red Spotted Grouper, Epinephelus akaara under Elevated Water Temperature

Higher thermal exposure can influence the blood cell morphology and count. Hence, based on the previous results (Rahman et al., 2019), the present study evaluated the morphometric indices of erythrocytes and their nucleus under different water temperatures (25°C, 28°C, 31°C, and 34°C) to investigate their use as an indicator of thermal stress in red spotted grouper, Epinephelus akaara. 180 healthy specimens of E. akaara were exposed to four temperature conditions (25°C as control, 28°C, 31°C, and 34°C) for 42 days, following 2 weeks of acclimation at 25°C. Erythrocyte major axis (EL), erythrocyte minor axis (EW), nucleus major axis (NL), and nucleus minor axis (NW) were examined from the blood smears on each sampling day (i.e., 2, 7, and 42 days of thermal exposure). EL and NL were significantly decreased, whereas EW and NW were increased at higher water temperature (31°C and 34°C). The major-minor axis proportions of erythrocytes and their nucleus (EL/EW; NL/NW) were decreased with increasing water temperature (31°C and 34°C). The strong relationships were observed among the morphometric indices of erythrocytes and their nucleus, especially in EL vs. NL and EW vs. NW. This study reveals that elevated water temperature (31°C and 34°C) can influence the major and minor axis morphometry of erythrocytes and their nucleus in red spotted grouper. These indices may be used as stress indicators to monitor the health status of E. akaara and probably for other fish species.

Preliminary Biochemical Description of Brain Oxidative Stress Status in Irritable Bowel Syndrome Contention-Stress Rat Model

Background and objectives: Oxidative stress and inflammation have been implicated in the etiology of irritable bowel syndrome (IBS), a common gastrointestinal functional disease. This study aimed to further characterize the contention-stress rat model by exploring a possible correlation between oxidative stress markers measured in brain tissues with behavioral components of the aforementioned model. Thus, it is hereby proposed a possible IBS animal model relevant to pharmacological and complementary medicine studies. Materials and Methods: Wild-type male Wistar rats (n = 5/group) were chronically exposed to 6-hour/day contention, consisting of isolating the animals in small, vital space-granting plastic devices, for seven consecutive days. Following contention exposure, temporal lobes were extracted and subjected to biochemical analyses to assess oxidative stress-status parameters. Results: Our results show increased brain oxidative stress in contention-stress rat model: decreased superoxide dismutase and glutathione peroxidase activities and increased malondialdehyde production in the IBS group, as compared to the control group. Furthermore, the biochemical ratios which are used to evaluate the effectiveness of an antioxidant system on oxidative stress could be described in this model. Conclusions: The correlations between the behavioral patterns and biochemical oxidative stress features could suggest that this may be a complex model, which can successfully mimic IBS symptomatology further providing evidence of a strong connection between the digestive system, enteric nervous system, and the central nervous system.

Chronic exposure of Oreochromis niloticus to sub-lethal copper concentrations: Effects on growth, antioxidant, non-enzymatic antioxidant, oxidative stress and non-specific immune responses

BACKGROUND

Trace elements of copper (Cu) are one of the main forms of ecological noxious waste in freshwater systems that affect the survival and development of organisms. The objective of the current study was to investigate the effects of chronic exposure to Cu on the growth, oxidative stress, immune and biochemical response in the Nile tilapia, Oreochromis niloticus.

METHODS

Three groups of O. niloticus were tested as follows; the first group was used as the control (not treated with Cu in water), while the 2nd and 3rd groups were exposed to (low) 40 μg L^-1 and (high) 400 μg L^-1 concentrations of Cu added to water, respectively. The duration of the experiment, which was conducted in triplicate, was 60 d. End points were evaluated on days 30 and 60. Following 30 d and 60 d of exposure to Cu, the fish were removed from experimental tanks to determine growth. Consequently, blood samples were collected from caudal veins at the end of the trial period (30 d and 60 d) and serum was separated to evaluate different immunological parameters, such as lysozymes (LYZ), respiratory burst activity (RBA) and myeloperoxidase (MPO). Gill and liver tissues were collected for evaluation of Cu and certain biochemical parameters as follows: antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST); non-enzymatic antioxidants such as glutathione (GSH) and metallothionein (MT), and oxidative stress indicators such as malondialdehyde (MDA) and protein carbonyl (PCO). The results pertaining to treatments and the control were compared using two-way ANOVA and Tukey's HSD test. The level of significance was set at P ≤ 0.05. Data were expressed as mean ± SD.

RESULTS

Chronic exposure to Cu did not induce any mortality in fish during the test period. However, following exposure to Cu, growth of fish in the exposed groups was affected more than that in the control group (unexposed to Cu). In addition, accumulation of Cu in the liver tissue was higher than that in the gill tissues of fish exposed to Cu, compared to that in the control. Gill and liver tissues of Cu-exposed fish showed a significant (P ≤ 0.05) reduction in the activities of the antioxidant enzymes, SOD, CAT, GPx, and GST, compared to those of unexposed fish. Non-enzymatic antioxidants, GSH and MT, in gill and liver tissues were significantly increased (P ≤ 0.05) in fish exposed to both concentrations of Cu, compared to those in unexposed fish. Oxidative stress indicators, MDA and PCO in gills and liver of Cu-exposed fish was significantly (P ≤ 0.05) at both tested concentrations, when compared to control group. Non-specific immune response of LYZ, RBA, and MPO activity in serum decreased significantly (P ≤ 0.05) in Cu-exposed fish, compared with that of unexposed fish.

CONCLUSION

Overall, the present results highlighted that chronic exposure to Cu ions may exert a strong effect on the antioxidant and immune responses of O. niloticus. Changes in antioxidant enzymes, oxidative stress effects and immune parameters during post-chronic metal exposure may indicate the potential of these parameters as biomarkers of metal toxicity in aquatic ecosystems.

Crude extract of cyanobacterium Radiocystis fernandoi strain R28 induces anemia and oxidative stress in fish erythrocytes

The cyanobacterium Radiocystis fernandoi has been frequently identified in cyanobacterial blooms in Brazil. Recently, R. fernandoi strain R28, which produces microcystin (MC)-RR and MC-YR, was isolated from the Furnas reservoir, Minas Gerais, Brazil. The present study evaluated the hematological variables and erythrocyte antioxidant responses, lipid peroxidation (LPO), and genotoxicity in a neotropical fish (Hoplias malabaricus) after acute and subchronic exposure to a crude extract (CE) of R. fernandoi strain R28. Acute exposure (12 or 96 h) consisted of a single intraperitoneal (i.p.) CE injection, and subchronic exposure consisted of one i.p. CE injection every 72 h for 30 days. After acute exposure, fish exhibited macrocytic anemia (12 h post-injection) followed by normocytic anemia (96 h post-injection). The increased activity of superoxide dismutase, glutathione peroxidase, glutathione-S-transferase, and the glutathione level in the erythrocytes did not prevent oxidative stress, manifested as lipid peroxidation and elevated DNA damage after acute exposure. After subchronic exposure, the hematological variables recovered, and the absence of erythrocyte oxidative stress suggests possible modulation by other biological factors, including a possible decrease in MC uptake by the cells and/or increasing detoxification efficiency that precludes erythrocyte damage.

Copper(II) generates ROS and RNS, impairs antioxidant system and damages membrane and DNA in human blood cells

Copper (Cu) is widely used in various industries, and human exposure to this metal results in severe multi-organ toxicity, which is thought to be due to the generation of free radicals by Fenton-like reaction. The generation of reactive oxygen as well as nitrogen species and free radicals results in induction of oxidative stress in the cell. We have studied the effect of different concentrations of Cu(II) on human erythrocytes and lymphocytes. Incubation of erythrocytes with copper chloride, a Cu(II) compound, enhanced the production of reactive oxygen and nitrogen species, decreased glutathione and total sulphydryl content and increased protein oxidation and lipid peroxidation. All changes were in a Cu(II) concentration-dependent manner. This strongly suggests that Cu(II) causes oxidative damage in erythrocytes. The activities of major antioxidant enzymes were altered, and antioxidant power was lowered. Cu(II) treatment also resulted in membrane damage in erythrocytes as seen by electron microscopy and lowered activities of plasma membrane-bound enzymes. Incubation of human lymphocytes with Cu(II) resulted in DNA damage when studied by the sensitive comet assay. These results show that Cu(II) exerts cytotoxic and genotoxic effects on human blood cells probably by enhancing the generation of reactive oxygen and nitrogen species.

Variation in transcriptional responses to copper exposure across Daphnia pulex lineages

Copper pollution is pervasive in aquatic habitats and is particularly harmful to invertebrates sensitive to environmental changes such as Daphnia pulex. Mechanisms of toxicity and tolerance to copper are not well understood. We used RNA-sequencing to investigate these mechanisms in three genetically distinct D. pulex clonal lineages with different histories of copper exposure. Upregulated genes after copper exposure were enriched with Gene Ontology (GO) categories involved in digestion, molting and growth, whereas downregulated genes after copper exposure were enriched in the metal-regulatory system, immune response and epigenetic modifications. The three D. pulex clones in our study show largely similar transcriptional patterns in response to copper, with only a total of twenty genes differentially expressed in a single clonal lineages. We also detected lower relative expression of some genes known to be important for copper tolerance, metallothionein and glutathione-S-transferase, in a sensitive lineage sampled from an uncontaminated habitat. Daphnia-specific genes (without orthologs outside the genus) and Daphnia-specific duplications (genes duplicated in the Daphnia lineage) were overrepresented in differentially expressed genes, highlighting an important role for newly emerged genes in tolerating environmental stressors. The results indicate that the D. pulex lineages tested in this study generally respond to copper stress using the same major pathways, but that the more resistant clone with previous copper exposure might be better able to regulate key genes. This finding highlights the important nuances in gene expression among clones, shaped by historical exposure and influencing copper tolerance.

Trace Metals in the Freshwater Fish Cyprinus carpio: Effect to Serum Biochemistry and Oxidative Status Markers

Interactions between trace metals, serum biochemical parameters, and oxidative status markers were observed. Freshwater fish Cyprinuscarpio blood samples (n = 38) were collected at the beginning of May (n = 19) and at the end of July (n = 19) of 2015. The concentrations of metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, Sr, and Zn) were analyzed in blood serum samples of fishes by inductively coupled plasma optical emission spectrometry (ICP-OES), and Hg was determined by cold-vapor atomic absorption spectroscopy (CV-AAS). The general scheme of descending concentrations of metals in blood serum samples was as follows: Zn > Fe > Cu > Sr > Cr > Ni > Mn > Pb > Se > As > Cd > Hg. Zn was the most accumulated element (4.42-119.64 mg/L) in both seasons. Overall, the trace element content was higher in spring season, except Hg, Ni, Se, and Sr. The seasonal effect was confirmed for Mn, Zn, Mg, Glu, AST, and Chol levels and for most oxidative status markers. The gender effect was confirmed for Sr, GPx, PC, Chol, and CK concentrations. Trace metals (especially Cd, Cr, Cu, Fe, Hg, Mn, Ni, Sr, Zn, As) significantly affected some blood serum chemistry parameters. The correlation analysis between oxidative status markers (ROS, TAC, MDA, SOD, GSH, UA, BHB, and Alb) and trace metal (Cd, Cu, Ni, Sr, Hg, Pb, Fe, Mn) content confirmed statistically significant interactions in both seasons. Obtained results indicate specific actions of trace metals.

NMR-based lipidomics of fish from a metal(loid) contaminated wetland show differences consistent with effects on cellular membranes and energy storage

Metals and metalloids are priority contaminants due to their non-degradable and bioaccumulative nature, and their ability to regulate and perturb diverse physiological processes in various species. Metal(loid)s are known to cause oxidative stress through production of reactive oxygen species (ROS), thus related endpoints like lipid peroxidation (LPO) have received considerable attention as biomarkers of exposure. However, the implications of metal(loid) toxicity including LPO on actual lipid profiles of species inhabiting contaminated systems are poorly understood. Here we applied Nuclear Magnetic Resonance (NMR) spectroscopy for untargeted lipidomics of mosquitofish (Gambusia holbrooki) collected from reference and metal(loid)-contaminated wetlands. We measured a range of trace elements in water and fish using inductively coupled plasma - mass spectrometry (ICP-MS), and interpreted site differences in the lipid profiles of mosquitofish in the context of known physiological responses to sub-lethal metal(loid) exposure. Results indicate deregulation of cellular membrane lipids (i.e., glycerophospholipids, cholesterol and sphingolipids) and increased energy storage molecules (i.e., triacylglycerols and fatty acids) in fish from the contaminated wetland. These responses are consistent with the recognised induction of oxidative stress pathways in organisms exposed to metal(loid)s and could also be symptomatic of mitochondrial dysfunction and endocrine disruption. It is difficult to attribute metal(loid)s as the sole factor causing differences between wetlands, and a more controlled experimental approach is therefore warranted to further explore mechanistic pathways. Nevertheless, our study highlights the benefits of untargeted ¹H NMR-based lipidomics as a relatively fast and simple approach for field-scale assessment and monitoring of organisms inhabiting metal(loid) contaminated environments.

Evaluation of naproxen-induced oxidative stress, hepatotoxicity and in-vivo genotoxicity in male Wistar rats

Naproxen (NP), a nonsteroidal anti-inflammatory drug (NSAID), is used for the treatment of common pain, inflammation and tissue damage. Genotoxicity testing of NP is of prime importance as it represents the largest group of drugs to which humans are exposed. Not many genotoxic studies are reported on NP; therefore, the present study investigated the detailed genotoxic and oxidative stress properties of NP. Male Wistar rats were administered NP orally at the doses of 38.91 and 65.78 mg/kg body weight for 14 days. Reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPO) activities/levels were measured in the liver, kidney and brain tissues. The aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) activities, and total bilirubin (TBIL) levels were measured in the liver tissues. Micronucleus frequency (micronucleus test MNT) and DNA damage (comet assay) were performed in the bone marrow cells and leukocytes, respectively. The results showed that NP treatment decreased the GSH levels and increased the SOD, CAT, LPO, ALT, AST, ALP and TBIL activities/levels compared to the control (p < 0.05). Results of MNT showed an increased micronucleus induction and comet assay showed a significant increase in DNA damage in the NP treated animals (p < 0.05). Treatment of NP resulted in the biochemical imbalance and induced oxidative stress that deteriorated the integrity of the cells, which caused significant damage to the genetic material and affected liver function in male Wistar rats. Therefore, NP is a potential genotoxic agent that induces genotoxicity and oxidative stress.

The pyrethroid λ-cyhalothrin induces biochemical, genotoxic, and physiological alterations in the teleost Prochilodus lineatus

The λ-cyhalothrin (CL) is a globally used pyrethroid insecticide that has been detected in different water bodies worldwide. However, studies on the effects of CL on freshwater fishes are still incipient. In this context, we evaluated the acute effects of a commercial formulation containing CL (Karate Zeon^® CS 50) in juveniles of the teleost Prochilodus lineatus exposed for 96 h to four concentrations of the active ingredient (5, 50, 250 and 500 ng.L^-1). Biochemical, physiological, and genotoxic biomarkers were evaluated in different organs of the fish. Exposure to CL induced significant changes in the enzymatic profiles of P. lineatus, with specific alterations in biotransformation enzymes and antioxidant defence in different tissues. Lipid peroxidation was observed in fish gills and kidney. Increases in esterases were observed in the liver of fish exposed to all CL concentrations evaluated, whereas acetylcholinesterase activity decreased in the muscles of fish at all concentrations. CL also promoted osmoregulatory disorders, with decreases in calcium and magnesium gill ATPases, with consequent hypocalcaemia, in addition an increase in sodium-potassium ATPase activity was observed in the gills of fish exposed to the highest CL concentration, probably in order to compensate a reduction in plasma sodium. Besides, increases in DNA damage were observed in the erythrocytes of fish exposed to all CL concentrations. Thus, despite the low CL concentrations and the short exposure time, this pyrethroid caused hematological adjustments, oxidative stress, osmoregulatory disorders, and DNA damage in P. lineatus, showing that the species is highly sensitive to the deleterious effects of CL.