Hematological and histopathological changes in silver catfish Rhamdia quelen (Siluriformes) exposed to clomazone herbicide in the Madre River, Santa Catarina State, Southern Brazil

The Influence of Clomazone-Based Herbicide Formulation on Common Carp (Cyprinus carpio) – A Laboratory Study Including Pathophysiological and Histopathological Assessment

Herbicides are widely applied in agriculture, which results in the pollution of ecosystems, including inland waters. Herbicides present in water may cause pathological changes in fish. The aim of this study was to evaluate the effects of a clomazone-based herbicide formulation, Command 480 EC, on the haematological and blood biochemical parameters of common carp as well as the microstructure of selected organs: gills, liver and trunk kidney. The fish were exposed to Command 480 EC at a concentration corresponding to 1 or 5 mg/l of clomazone (groups COM1 and COM2, respectively) for 10 days. The conducted analyses showed that the treatment caused numerous changes in red blood cell parameters, no significant changes in WBC count (in comparison to the control), and only a few transient changes in the leukogram. The only significant change in the biochemical parameters in comparison to the control was a decrease in the triglyceride concentration in fish observed after 3 days (group COM1) and 10 days (group COM2) of exposure to this herbicide. No considerable histopathological alterations were observed. The results of the present study suggest that exposure to the applied clomazone-based formulation can cause pathophysiological changes in common carp. It was also observed that blood parameters (especially haematological ones) are more sensitive markers of exposure to Command than the microstructure of the tested organs.

Short-term immunotoxicity induced by florpyrauxifen-benzyl herbicide exposure in the spleen of male albino mice

Florpyrauxifen-benzyl (FPB) is a new arylpicolinate systemic herbicide that has been used to control or suppress the majority of herbicide-resistant biotype weeds in rice. To our knowledge, the impact of FPB on the immune system remains undetected thus far. Hence, this work aimed to address the toxic effects of FPB and the possible related mechanisms on the spleen of exposed mice. Initially, an acute toxicological test was performed to ascertain the median lethal dose (LD50) of FPB for 24 h which was found to be 371.54 mg/kg b.wt. For mechanistic evaluation of FPB toxicity, three sublethal doses (1/20th, 1/10th, and 1/5th LD50) were orally administered to mice for 21 consecutive days. Changes in spleen relative weight, oxidative status, apoptotic and inflammatory markers, histopathological alterations were evaluated. Following the FPB exposure, significant (p < 0.05) decline in spleen index, apoptotic features, histolopathological changes were observed. Additionally, excessive oxidative stress in spleen tissues was monitored by downregulating antioxidant enzymes and upregulating the oxidant parameters. Furthermore, exposure to FPB resulted in notable activation of the NF-қB signaling pathway, accompanied by elevated levels of pro-inflammatory cytokines (namely, IL-1β and TNF-α) as well as CD3 and CD19 levels have decreased significantly in spleen tissues. Collectively, FPB exposure exhibited apoptosis, oxidative stress, immunosuppression, and inflammatory response in a dose-dependent manner, leading to spleen tissue damage and immunotoxicity. Further studies on FPB is recommended to outstand its hazards on ecosystems.

Ferulic acid attenuates difenoconazole exposure induced liver injury in carp by modulating oxidative damage, inflammation and apoptosis

Difenoconazole (DFZ) is a widely used triazole fungicide in agricultural production. However, the presence of DFZ residue in the environment poses a significant risk to non-target organisms. Ferulic acid (FA) is a phenolic compound known for its antioxidant and anti-inflammatory properties. This study aims to investigate the hepatic damage caused by DFZ in carp and explore the mechanism through which FA alleviates this damage. The findings revealed that FA enhanced the antioxidant capability of the carp's liver and reduced the accumulation of reactive oxygen species (ROS) in the liver tissue. Moreover, FA regulated the transcriptional levels of inflammation-related factors, effectively preventing the inflammatory response triggered by the NF-κB signaling pathway. Additionally, TUNEL results demonstrated that DFZ initiated apoptosis, while dietary supplementation with FA decreased the protein expression levels of Bax and Cytochrome C (Cyt c) and the transcriptional levels of bax, caspase3, caspase9, p53 genes. Furthermore, FA increased the protein expression and transcriptional levels of Bcl-2. In conclusion, FA protects against liver injury induced by DFZ exposure in carp by modulating oxidative damage, inflammation, and apoptosis.

The Use of Multiple Biomarkers to Assess the Health of Anuran Amphibians in the Brazilian Cerrado Savanna: An Ecotoxicological Approach

Changes in the natural landscape and the indiscriminate use of pesticides can have a major impact on aquatic environments and have contributed to the worldwide decline of amphibian populations. In the present study, we sampled tadpoles of three anuran amphibians (Boana albopunctata, Physalaemus cuvieri, and Dendropsophus minutus) from ponds in six different agricultural landscapes of the Brazilian Cerrado savanna and evaluated whether and to what extent genotoxic and mutagenic damage was related to land use (the amount of forest and agricultural remnants, and related physicochemical factors) and the presence of pesticides in the water of the study ponds. We also evaluated the hepatotoxicity in P. cuvieri, which was the most abundant species at five of the six sampling points. Clomazone and atrazine were the most common pesticides found in the ponds. The B. albopunctata and P. cuvieri tadpoles presented similar patterns of DNA damage among the sampling points. The least DNA damage was found in the D. minutus tadpoles, although this species was present in only one of the study ponds. More binucleated and anucleated cells were observed in B. albopunctata, but there was no significant variation among species in terms of the number of micronuclei or other erythrocytic nuclear abnormalities. Land use and physicochemical factors did not explain the variation in the DNA damage observed in the three anurans. The hepatotoxicity analyses of P. cuvieri revealed the presence of a series of alterations, including the enlargement of the sinusoids, vacuolization of the hepatocytes, the infiltration of inflammatory cells, hepatic steatosis, and dilation of the blood vessels. The interaction between physicochemical factors and the biomarkers analyzed in the present study is complex. In particular, it will be important to better elucidate which factors are contributing, either directly or indirectly, to the decline of anuran amphibian populations, especially in threatened biomes, such as the Brazilian Cerrado. In this case, we would encourage further in situ studies that assess the ecotoxicology of the landscape, together with the systematic monitoring of aquatic environments, to guarantee the long-term integrity of amphibian populations, and those of other organisms that play an essential functional role in the ecosystem. Environ Toxicol Chem 2023;42:2422-2439. © 2023 SETAC.

Ferulic acid attenuated difenoconazole-induced immunotoxicity in carp by inhibiting TRAF/TAK1/NF-κB, Nrf2 and p53 pathways

Difenoconazole (DFZ) is a classical triazole fungicide that causes immunosuppression in non-target organisms. Ferulic acid (FA) is a polyphenolic molecule found in nature that has antioxidant and anti-inflammatory activities. The purpose of this investigation was to see if FA could prevent DFZ-induced immunosuppression and to identify the potential mechanisms. Carp were exposed to 1/10 LC50 of DFZ as well as fed normal feed or feed containing dietary additive FA for 30 d. It was found that DFZ-induced immunosuppression could be improved by FA, as evidenced by upregulation of Hb, C3 and IgM and downregulation of LDH. It was then investigated that FA could ameliorate DFZ-induced splenic injury through p53-mediated apoptosis. At the same time, enhancing the levels of CAT, GSH and T-AOC in spleen and transcription levels Nrf2 signaling pathway related genes indicated that FA reduced oxidative damage caused by DFZ by blocking the Nrf2 signaling pathway. In addition, FA inhibited the inflammatory response triggered by TRAF/TAK1/NF-κB signaling pathway, downregulated the transcript levels of pro-inflammatory factors (il-1β, tnf-α, il-6) and the level of NLRP3 inflammasome (NRLP3, ASC, Caspase 1), and upregulated the transcript levels of anti-inflammatory factors (tgf-β1, il-10). In conclusion, the above results suggested that FA mediated TRAF/TAK1/NF-κB, Nrf2, and p53 pathways to attenuate DFZ-induced inflammation, oxidative stress, and apoptosis thereby enhancing the immune capacity of carp.

Difenoconazole causes spleen tissue damage and immune dysfunction of carp through oxidative stress and apoptosis

As the use of pesticides increases year after year, so does the level of residual pesticides in the aquatic environment, posing a serious threat to non-target organisms. Difenoconazole (DFZ), a class of long-lasting fungicides and residues in the marine environment, has been shown to cause damaging effects on different organs of aquatic organisms. However, there is no research on the damage of DFZ to carp spleen tissue. This study aimed to investigate the acute toxic effects of DFZ on the spleen tissue of carp (Cyprinus carpio) by exposing juvenile carp to environmentally relevant concentrations of DFZ. We randomly selected 30 carp, divided them into the Control, Low, and High groups, and then exposed the three groups to 0, 0.488 mg/L DFZ, and 1.953 mg/L DFZ for 96 h respectively. We then investigated the toxic effects caused by DFZ on carp and spleen tissues by detecting changes in spleen histopathologic damage, apoptosis, oxidative stress, inflammation, and blood biochemical parameters. We found that DFZ causes severe histopathology in spleen tissue, including ballooning, structural relaxation, and giant mitochondria. In addition, we found that DFZ caused excessive apoptosis in spleen tissue by TUNEL staining and expression levels of apoptosis-related genes (caspase3, caspase8, caspase9, fas, bax, bcl-2, and p53). The activities and transcript levels of the antioxidant enzymes SOD, CAT, and GSH-Px were significantly down-regulated. In addition, DFZ led to a significant increase in activation of the NF-κB signaling pathway and mRNA levels of pro-inflammatory cytokines il-6, il-1β, and tnf-α, and a substantial decrease in mRNA levels of anti-inflammatory cytokines il-10 and tgf-β1 in spleen tissue. Blood biochemical parameters showed that DFZ exposure significantly reduced erythrocyte, leukocyte, hemoglobin, C3, and IgM levels. Collectively, DFZ exposure induced apoptosis, immunosuppression, oxidative stress, and inflammatory responses in the spleen tissue of carp, resulting in spleen tissue damage.

Assessment of biochemical, hematological and behavioral biomarkers of Cyprinus carpio on exposure to a type-II pyrethroid insecticide Alpha-cypermethrin

This study assessed some important physiological biomarkers of freshwater edible fish Cyprinus carpio following exposure to 10 % (T1) and 20 % (T2) sublethal concentrations of Alpha-cypermethrin (A-cyp) over a total period of 45 days. Behavioral responses were noticed and Kaplan-Meier survival curves were prepared during acute toxicity study. Total serum protein concentration, total erythrocyte count, hemoglobin, packed cell volume, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and total leukocytes count were decreased significantly (p < 0.05), while the blood glucose, total serum lipid concentration, and clotting time were increased significantly (p < 0.05) over control. The most affected fish group and most significantly altered biomarker under toxic stress of A-cyp were identified using integrated biomarker response (IBR). The biomarker response index (BRI) values measured the overall health status of the treated fish and indicated that moderate adverse effects were exerted on the fish group exposed to T2 for 45 days.

Multiple biomarkers based appraisal of deltamethrin induced toxicity in silver carp (Hypophthalmichthys molitrix)

Deltamethrin (DLM) is α-cyano (type II) synthetic pyrethroid. DLM exposure leads to strong neurotoxic effects and a number of complex toxicological syndromes. The current study assessed DLM mediated oxidative stress, behavioral, hematological, histopathological, and biochemical toxic effects on silver carp (Hypophthalmichthys molitrix). Exposure to an acute concentration (2 μg/L) of DLM resulted in different behavioral inconsistencies and a time-dependent significant (P < 0.05) change in the hematology and serum biochemistry of silver carp. A significant (P < 0.05) increase in the activities of reactive oxygen species, lipid peroxidation, and antioxidant enzymes whereas a significant decrease in total protein contents in the liver, gills, brain, and muscle tissues were observed. DLM exposure increased the activities of metabolic enzymes in the gills, muscles, and liver of silver carp. A significant (P < 0.05) increase in DNA damage in peripheral blood erythrocytes was evident. DLM exposure led to a time-dependent significant (P < 0.05) increase in the whole-body cortisol and blood glucose level, while a significant decrease in acetylcholine esterase activity in the brain, liver, and muscle tissues. Different histopathological changes in the liver, gills, brain, and intestine were observed, however, no significant change in the gross anatomy and morphometric parameters of the fish was observed. The current study provides valuable information for devising better strategies regarding environmental management, chemicals' risk assessment, biodiversity conservation, and monitoring of the aquatic organisms. DLM was concluded to be highly toxic to fish. The extensive use of DLM should be prohibited or allowed under strict environmental laws; otherwise, it might lead to the extermination of the susceptible wildlife, such as commercially very valuable but nearly threatened silver carp.

Developmental toxicity and biological responses of zebrafish (Danio rerio) exposed to anti-inflammatory drug ketoprofen

Ketoprofen a nonsteroidal anti-inflammatory drug (NSAID) is widely used in over-the-counter to treat pain, swelling and inflammation. Due to extensive application these drugs has been detected in surface waters which may create a risk to aquatic organisms. The aim of the present study is to assess the ecotoxicity of ketoprofen at different concentrations (1, 10 and 100 μg/ml) on embryos and adult zebrafish (1, 10 and 100 μg L^-1) under laboratory conditions. In embryos, concentration dependent developmental changes such as edema, spinal curvature, slow heartbeat, delayed hatching, and mortality rate were observed. In adult zebrafish, biochemical enzymes such as AST, ALT and LDH activities were significantly (P < 0.05) increased whereas a decrease in Na⁺/K⁺-ATPase activity was noticed in all the tested concentrations of the drug ketoprofen. Similarly, exposure of ketoprofen caused a significant decrease in antioxidant levels in liver tissue (SOD, CAT, GSH, GPx, and GST). However, lipid peroxidation (LPO) level in liver tissue was found to be increased. The histopathological studies further evidenced the impact of ketoprofen in the liver tissue of zebrafish. The present result concludes that ketoprofen could have an impact on the development and biological endpoints of the zebra fish at above concentrations. The malformation in the development of the embryo and changes in the biological end points may provide integrated evaluation of the toxic effect of ketoprofen on zebrafish in a new perspective.

Toxicity of clomazone and its formulations to zebrafish embryos (Danio rerio)

Herbicides are the most widely used group of pesticides but after reaching water bodies they are able to cause adverse effects on non-target organisms. Different formulations using the same active ingredient are frequently available, which raises the issue of potential influence of different formulation types on herbicide toxicity. The present study evaluated the toxicity and teratogenic effects of the active ingredient clomazone and its two formulations (Rampa^® EC and GAT Cenit 36 CS, both containing 360g a.i./l of clomazone) on zebrafish embryos. The crucial difference between the two formulation types is the way of active substance release. This investigation is the first report on zebrafish embryotoxicity of both clomazone and its formulations. The technical active ingredient and formulations caused mortality and diverse teratogenic effects, showing different levels of toxicity. The LC₅₀ values for the technical ingredient, Rampa^® EC and GAT Cenit 36 CS were 61.4, 9.6 and 92.5mg a.i./l, respectively. Spontaneous movements in 22 hpf embryos decreased under exposure to both the technical ingredient and formulations. A significant number of underdeveloped embryos was detected after exposure to clomazone and Rampa^® EC, while no underdevelopment was noted in embryos exposed to GAT Cenit 36 CS. Exposure to the technical ingredient and formulations led also to a series of morphological changes and interfered with the growth of zebrafish embryos. The EC₅₀ based on detection of edemas, spine and tail tip deformations and gas bladder absence (120hpf) was 12.1, 10.1 and 24.1mg/l for technical clomazone, Rampa^® EC and GAT Cenit 36 CS, while teratogenicity index (TI) based on LC₅₀/EC₅₀ ratio was 5.1, 1 and 3.8, respectively. The data in this study showed that the emulsifiable concentrate formulation (Rampa^® EC) caused statistically significantly higher toxicity, and the aqueous capsule suspension (GAT Cenit 36 CS) lower toxicity than technical clomazone. It indicates that different formulations with the same active ingredient may have different environmental impacts, which is why risk assessment based only on active ingredient toxicity might not be sufficient in terms of preventing formulation effects on the environment.

Metabolic parameters and oxidative balance in juvenile Rhamdia quelen exposed to rice paddy herbicides: Roundup®, Primoleo®, and Facet®

The present study sought to assess the response of Rhamdia quelen juveniles (6-8 cm total body length) to exposure to different concentrations of three herbicides: Roundup® Original (18, 36, 72, and 144 μg/L), Primoleo® (2.5, 5, 10, and 15 μg/L), and Facet® (1.75, 3.5, 7, and 14 μg/L). Total protein (TP), glycogen (GG), total lipids (TL), triacylglycerols (TAG), lipid peroxidation (TBARS), and activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in gills, liver, kidneys, and muscle were measured by spectrophotometry. Roundup® (glyphosate) reduced the TP, GG, and TL in gills and TL in liver and kidney and increased TP in liver and increased GG in muscle. In contrast to Primoleo® (atrazine), all tissues stored TAG and consumed LT, besides the gills also reduced PT. There was still an increase in GG in the kidneys and muscle. Facet® (quinclorac) induced changes mainly in the liver (increased TP, TL, and TAG content) and muscle (increased GG, TL, and TAG depletion). Gill tissue exhibited TP depletion alone, and kidney tissue metabolism was unchanged. This fish species appears capable of modulating its enzymes to the point where it sustains no oxidative damage as a result of exposure to the herbicides glyphosate (possibly due to increased CAT activity), atrazine (despite no changes in SOD or CAT activity), and quinclorac (with increased lipid peroxidation, particularly in gill, kidney, and muscle tissue, despite elevated SOD activity). Although it is not considered a target species, R. quelen suffers harmful effects from interaction with these herbicides.

Influences of Sex and Age on the Hematological Profile of the Jundiá (Silver Catfish) Rhamdia quelen

In this study, sex and age influenced the hematological profiles of Jundiá (Silver Catfish) Rhamdia quelen. Females showed lower levels of hemoglobin, young fish increased lymphocyte counts, and older fish increased hematocrit values. These results indicate that, depending on age and sex, the fish have disparate hematological profiles. For this reason, it is important to consider the sex and age of an R. quelen when examining the impact of environmental and management factors on this species in terms of their hematological profiles. Received May 24, 2015; accepted March 24, 2016.

Hepatic effects of the clomazone herbicide in both its free form and associated with chitosan-alginate nanoparticles in bullfrog tadpoles

The use of agrochemicals in agriculture is intense and most of them could be carried out to aquatic environment. Nevertheless, there are only few studies that assess the effects of these xenobiotics on amphibians. Clomazone is an herbicide widely used in rice fields, where amphibian species live. Thus, those species may be threatened by non-target exposure. However, nanoparticles are being developed to be used as a carrier system for the agrochemicals. Such nanoparticles release the herbicide in a modified way, and are considered to be more efficient and less harmful to the environment. The aim of this study was to comparatively evaluate the effect of clomazone in its free form and associated with nanoparticles, in the liver of bullfrog tadpoles (Lithobates catesbeianus) when submitted to acute exposure for 96 h. According to semi-quantitative analysis, there was an increase in the frequency of melanomacrophage centres, in the accumulation of eosinophils and in lipidosis in the liver of experimental groups exposed to clomazone - in its free form and associated with nanoparticles - in comparison with the control group, and the nanotoxicity of chitosan-alginate nanoparticles. The increase of melanomacrophage centres in all exposed groups was significant (P < 0.0001) in comparison to control group. Therefore, the results of this research have shown that exposure to sublethal doses of the herbicide and nanoparticles triggered hepatic responses. Moreover, these results provided important data about the effect of the clomazone herbicide and organic nanoparticles, which act as carriers of agrochemicals, on the bullfrog tadpole liver.

In vitro mucus transportability, cytogenotoxicity, and hematological changes as non-destructive physiological biomarkers in fish chronically exposed to metals

The biomonitoring of fish using biomarkers represents a useful tool for the assessment of aquatic pollution. This study evaluated the sublethal toxic effects of aquatic pollution on fish collected from a site contaminated by metals. Water and fish (Oreochromis niloticus) samples were collected from a pond in the Parque Ecológico do Tietê (PET) that lies along the Tietê River (São Paulo, Brazil), and from a control site (an experimental fish farm). The metal content of the water was evaluated, and fish were used to examine the properties of gill mucus and blood. The PET fish were evaluated for alterations in the in vitro transportability of mucus and changes in blood properties (e.g., cell volume, hemoglobin concentration, red blood cells, and white blood cell count). The results of the water analyzes indicated metal levels above the legal standards for Fe (0.71 mg/L), Ni (0.06 mg/L), Mn (0.11 mg/L), and Pb (0.48 mg/L). Compared to the controls, the hematologic parameter analyzes of PET fish revealed significantly higher numbers of erythrocytes (RBC), leukocytes (WBC), lymphocytes, erythroblasts, and Mean Corpuscular Volume (MCV); however, the hemoglobin content and Mean Corpuscular Hemoglobin Concentration (MCHC) values were significantly lower. The frequencies of nuclear abnormalities and micronuclei were significantly higher and the mucociliary transport was significantly lower in PET fish than in the controls. These results suggest that fish from the contaminated site exhibit a series of physiological responses, which probably indicate health disturbances. Furthermore, the results suggest that blood and mucus are promising, non-destructive targets for use in the monitoring of pollution.