Clinicohematological, Mutagenic, and Oxidative Stress Induced by Pendimethalin in Freshwater Fish Bighead Carp (Hypophthalmichthys nobilis)

Environmental presence and toxicological outcomes of the herbicide pendimethalin in teleost fish

Herbicides are often detected in aquatic ecosystems due to residential and agricultural applications and can harm aquatic organisms once deposited into water systems. Pendimethalin is part of the dinitroaniline chemical family and is applied to crops like corn, legumes, potatoes, and soybeans. The potential toxicity of pendimethalin to aquatic species is understudied compared to other widely studied herbicides, like atrazine and glyphosate. The objectives of this review were to (1) collate information on sub-lethal responses to pendimethalin exposure in fish, (2) evaluate how exposure studies relate to environmental concentrations, and (3) identify putative bioindicators for exposure studies. Overall, studies reporting pendimethalin in water systems worldwide indicate a range of 100-300 ng/L, but levels have been reported as high as ~15 µg/g in sediment. In teleost fish, studies demonstrate developmental toxicity, immunotoxicity, and behavioral disruptions. The strongest evidence for pendimethalin-induced toxicity involves oxidative stress, although studies often test toxicity at higher concentrations than environmentally relevant levels. Using the Comparative Toxicogenomics Database, pathway analysis reveals linkages to neurotoxicity and mechanisms of neurodegeneration like "Ubiquitin Dependent Protein Degradation", "Microtubule Cytoskeleton", "Protein Oxidation and Aggregation in Aging", and "Parkinson's Disease". Other prominent pathways included those related to mTOR signaling and reproduction. Thus, two potential mechanisms underlying pendimethalin-induced toxicity in fish include the neural and reproductive systems. This review synthesizes current data regarding environmental fate and ecotoxicology of pendimethalin in teleost fish and points to some putative physiological and molecular responses that may be beneficial for assessing toxicity of the herbicide in future investigations.

Tissue Accumulation, Cytotoxicity, Oxidative Stress, and Immunotoxicity in African Catfish, Clarias gariepinus Exposed to Sublethal Concentrations of Hexavalent Chromium

Hexavalent chromium (Cr6+) is one of the stable oxidation states of chromium that has been reported to elicit various toxic effects in aquatic organisms. However, the mechanisms of Cr6+ toxicity are still poorly understood. Thus, the present study investigated the tissue accumulation, cytotoxic, oxidative stress, and immunotoxic effects of Cr6+ in juvenile Clarias gariepinus. The fish were exposed to waterborne Cr6+ concentrations (0, 0.42, 0.84, and 1.68 mg/L) for 28 days, after which they were sacrificed and various organs were harvested for the determination of Cr6+ levels. Other parameters that were indicators of oxidative stress, cytotoxicity, and immunotoxicity were measured. Cr6+ accumulated more in the kidney and liver of the exposed fish, especially at the highest concentration. The levels of lipid peroxidation and DNA fragmentation increased significantly in the exposed fish. The activities of superoxide dismutase and lactate dehydrogenase increased significantly in exposed fish compared to the control. The total white blood cells, lymphocytes, and neutrophils counts were significantly higher in the exposed fish compared to the control fish. The respiratory burst activity decreased significantly in the exposed fish while the myeloperoxidase content did not differ significantly. There were upregulations of TNF-α and HSP 70 while CYP II and MHC 2 were downregulated in the exposed fish. Also, exposure to Cr6+ resulted in various histopathological alterations in the architecture of the head kidney. The results indicate concentration-dependent toxic effects of Cr6+ in C. gariepinus. The study reveals the potentials of Cr6+ to accumulate in the different tissues of fish and caused cytotoxic, oxidative stress, and immunotoxic effects in the exposed fish.

Effect of glyphosate-based herbicide roundup on hemato-biochemistry of Labeo rohita (Hamilton, 1822) and susceptibility to Aeromonas hydrophila infection

In the present study, comprehensive research was executed to investigate the salient toxic effects of glyphosate herbicide in static water system by evaluating the haemato-biochemical profiles of Labio rohita. A challenge study against Aeromonas hydrophila was conducted to determine disease susceptibility of the fish, treated to varying concentrations of commercial-grade glyphosate herbicide. A static range finding bioassay and definitive test revealed that the 96-h LC50 value of glyphosate was 10.16 mg L-1. The experimental fish were subjected to three sub-lethal concentrations of 2.06, 1.03, and 0.63 mg l-1 for 28 days and changes were documented bi-fortnightly to study haemato-biochemical alterationsin the fish. Significantly (p < 0.05) low values in red blood corpuscles (RBC), hemoglobin (Hb), and hematocrit value (Hct) were documented. In contrast, a significant (p < 0.05) escalation in white blood corpuscles (WBC) was documented in comparison to the control. Biochemical and stress markers such as blood glucose, total protein, and alkaline phosphatase (ALP) were significantly (p < 0.05) low, whereas serum glutamate pyruvate transaminase (SGPT) and serum glutamate oxaloacetate transaminase (SGOT) escalated significantly (p < 0.05). Chronic exposure to glyphosate, on the other hand, had the least effect on the Na+ and K+ ions. Further, a challenge assay against A. hydrophila at three sub-lethal glyphosate concentrations demonstrated a synergistic impact that reduced the fish survivability. The findings conclude that persistent low glyphosate concentrations in aquatic ecosystems show significant pathophysiological changes in L. rohita, with increased vulnerability to infections. Altogether, our findings indicate the need to further study the possible assessment for a sustainable bio-remediation technique, mitigation of the detrimental effects of glyphosate exposure in fish, and recommendation of an acceptable residue concentration of the glyphosate in aquatic ecosystem.

Effects of microplastics, pesticides and nano-materials on fish health, oxidative stress and antioxidant defense mechanism

Microplastics and pesticides are emerging contaminants in the marine biota, which cause many harmful effects on aquatic organisms, especially on fish. Fish is a staple and affordable food source, rich in animal protein, along with various vitamins, essential amino acids, and minerals. Exposure of fish to microplastics, pesticides, and various nanoparticles generates ROS and induces oxidative stress, inflammation, immunotoxicity, genotoxicity, and DNA damage and alters gut microbiota, thus reducing the growth and quality of fish. Changes in fish behavioral patterns, swimming, and feeding habits were also observed under exposures to the above contaminants. These contaminants also affect the Nrf-2, JNK, ERK, NF-κB, and MAPK signaling pathways. And Nrf2-KEAP1 signalling modulates redox status marinating enzymes in fish. Effects of pesticides, microplastics, and nanoparticles found to modulate many antioxidant enzymes, including superoxide dismutase, catalase, and glutathione system. So, to protect fish health from stress, the contribution of nano-technology or nano-formulations was researched. A decrease in fish nutritional quality and population significantly impacts on the human diet, influencing traditions and economics worldwide. On the other hand, traces of microplastics and pesticides in the habitat water can enter humans by consuming contaminated fish which may result in serious health hazards. This review summarizes the oxidative stress caused due to microplastics, pesticides and nano-particle contamination or exposure in fish habitat water and their impact on human health. As a rescue mechanism, the use of nano-technology in the management of fish health and disease was discussed.

Chronic toxicity of broflanilide in Daphnia magna: changes in molting, behavior, and gene expression

Broflanilide is a novel pesticide used in agriculture that binds to unique receptors on pests; however, the widespread use of broflanilide has led to toxicity in Daphnia magna. At present, little information on the potential threats broflanilide imposes on D. magna is available. Therefore, the present study examined the chronic toxicity of broflanilide in D. magna by comparing changes in molting, neurotransmitter function, and behavior. The results showed that broflanilide caused chronic toxicity in D. magna at a concentration of 8.45 μg/L, and growth, development, reproduction, and the development of offspring were affected. In addition, broflanilide affected the molting of D. magna by significantly inhibiting the expression of chitinase, ecdysteroid, and related genes. Broflanilide also affected the expression of γ-glutamic acid, glutamine, gamma-aminobutyric acid, 5-hydroxytryptamine, 5-hydroxytryptophan, dopa, and dopamine. Furthermore, the swimming distance and speed of D. magna were reduced. Taken together, the results demonstrate the chronic toxicity and exposure risk of broflanilide in D. magna.

Copper sulfate induces clinico-hematological, oxidative stress, serum biochemical and histopathological changes in freshwater fish rohu (Labeo rohita)

Despite being an essential trace element for numerous metabolic processes and micronutrients, copper (Cu) has induced adverse effects on the environment and public health due to its continuous and widespread use for the last several decades. The current study assessed the hematological and histopathological alterations in the freshwater fish (Labeo rohita) exposed to graded concentrations of copper sulfate. For this purpose, L. rohita fish (n = 72), weighing ~200-215 g, were randomly divided into four experimental groups and then exposed to acute doses of CuSO4, i.e., control, 0.28, 0.42, and 0.56 μgL-1. For comparative analysis of hematological and biochemical changes, blood/serum samples were obtained on 12, 24, and 36 days. Overall, the body weight of fish decreased with the time and dose of CuSO4; as the dose increases, body weight decreases. Dose and time-dependent results were observed in other parameters also. Results showed a significant increase in leukocytes, whereas red blood cells count, Hb, and Hct were significantly reduced in treated groups compared to the control. The mean corpuscular hemoglobin (MHC) and mean corpuscular hemoglobin concentration (MCHC) showed a non-significant decrease in treated groups compared to the control group. Serum biochemical parameters, including total proteins, albumin, and globulin, decreased significantly (p < 0.05). At the same time, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), glucose, and cholesterol were significantly (p < 0.05) increased in the treated groups compared to the control group. Significantly (p < 0.05) increased levels of lipid peroxidation while decreased values of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (RGSH) in the blood of fish were recorded. Histopathological examination of fish gills, liver, and kidneys showed inflammation and degenerative changes due to CuSO4 exposure. In the brain tissue, degenerative changes like neuron necrosis, intracellular edema, cytoplasmic vacuolization, and congestion were observed. In conclusion, the study indicates that exposure to copper sulfate, even in smaller concentrations, can cause adverse hematological and histopathological changes in L. rohita fish.

Effects of thiram exposure on liver metabolism of chickens

Pesticides are widely used to control crop diseases, which have made an important contribution to the increase of global crop production. However, a considerable part of pesticides may remain in plants, posing a huge threat to animal safety. Thiram is a common pesticide and has been proven that its residues in the feed can affect the growth performance, bone formation, and intestinal health of chickens. However, there are few studies on the liver metabolism of chickens exposed to thiram. Here, the present study was conducted to investigate the effect of thiram exposure on liver metabolism of chickens. Metabolomics analysis shows that 62 metabolites were down-regulated (ginsenoside F5, arbekacin, coproporphyrinogen III, 3-keto Fusidic acid, marmesin, isofumonisin B1, 3-Hydroxyquinine, melleolide B, naphazoline, marmesin, dibenzyl ether, etc.) and 35 metabolites were up-regulated (tetrabromodiphenyl ethers, deoxycholic acid glycine conjugate, L-Palmitoylcarnitine, austalide K, hericene B, pentadecanoylcarnitine, glyceryl palmitostearate, quinestrol, 7-Ketocholesterol, tetrabromodiphenyl ethers, etc.) in thiram-induced chickens, mainly involved in the metabolic pathways including glycosylphosphatidylinositol (GPI)-anchor biosynthesis, porphyrin and chlorophyll metabolism, glycerophospholipid metabolism, primary bile acid biosynthesis and steroid hormone biosynthesis. Taken together, this research showed that thiram exposure significantly altered hepatic metabolism in chickens. Moreover, this study also provided a basis for regulating the use and disposal of thiram to ensure environmental quality and poultry health.

Nuclear and Morphological Alterations in Erythrocytes, Antioxidant Enzymes, and Genetic Disparities Induced by Brackish Water in Mrigal Carp (Cirrhinus mrigala)

Salinization of aquatic ecosystem, abrupt climate change, and anthropogenic activities cause adverse impact on agricultural land/soil as well as the aquaculture industry. This experimental study was designed to evaluate different biomarkers of oxidative stress, antioxidant enzymes, and genotoxic potential of diverse salinities of brackish water on freshwater fish. A total of 84 fresh water mrigal carp (Cirrhinus mrigala) were randomly segregated and maintained in four groups (T0, T1, T2, and T3) in a glass aquarium under similar laboratory conditions at various salinity levels (0, 3, 5, and 7 parts per thousand) to determine the pathological influence of brackish water. All the fish in groups T1, T2, and T3 were exposed to various salinity levels of brackish water for a period of 90 days while the fish of group T0 served as the control group. The experimental fish reared in different groups T1, T2, and T3 displayed various physical and behavioral ailments. The results revealed significantly augmented quantity of different oxidative stress indicators including reactive oxygen species (ROS) and thiobarbituric acid reactive substance (TBARS) in different visceral tissues (kidneys, liver, and gills) of exposed fish. Different antioxidant enzymes such as reduced glutathione (GSH), peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) along with total proteins were remarkably reduced in the kidneys, gills, and liver tissues. Results showed significantly increased values of different nuclear abnormalities (erythrocyte with micronucleus, erythrocyte with condensed nucleus, and erythrocyte with lobed nucleus) and morphological changes (pear shaped erythrocyte, spindle-shaped erythrocytes, and spherocyte) in red blood cells of experimental fish. The results on genotoxic effects exhibited significantly increased DNA damage in isolated cells of liver, kidneys, and gills of exposed fish. The findings of our experimental research suggested that brackish water causes adverse toxicological impacts on different visceral tissues of fresh water fish at higher salinity level through disruption and disorder of physiological and biochemical markers.

ZOMEC via the p-Akt/Nrf2 Pathway Restored PTZ-Induced Oxidative Stress-Mediated Memory Dysfunction in Mouse Model

A new mechanistic approach to overcome the neurodegenerative disorders caused by oxidative stress in Alzheimer's disease (AD) is highly stressed in this article. Thus, a newly formulated drug (zinc ortho-methyl carbonodithioate (ZOMEC)) was investigated for five weeks on seven-week-old BALB/c male mice. ZOMEC 30 mg/kg was postadministered intraperitoneally during the third week of pentylenetetrazole (PTZ) injection. The brain homogenates of the mice were evaluated for their antioxidant potential for ZOMEC. The results including catalase (CAT), glutathione S transferase (GST), and lipid peroxidation (LPO) demonstrated that ZOMEC significantly reverted the oxidative stress stimulated by PTZ in the mouse brain. ZOMEC upregulated p-Akt/Nrf-2 pathways (also supported by molecular docking methods) to revoke PTZ-induced apoptotic protein markers. ZOMEC reversed PTZ-induced neuronal synapse deficits, improved oxidative stress-aided memory impairment, and inhibited the amyloidogenic pathway in mouse brains. The results suggested the potential of ZOMEC as a new, safe, and neurotherapeutic agent to cure neurodegenerative disorders by decreasing AD-like neuropathology in the animal PTZ model.

Evaluation of Hematological, Oxidative Stress, and Antioxidant Profile in Cattle Infected with Brucellosis in Southern Punjab, Pakistan

Brucellosis is a well-known and harmful zoonotic disease that poses a severe threat to public health and wild and dairy animals. Due to a lack of monitoring and awareness, disease incidence has increased. Therefore, this study was conducted for the first time to ascertain the status of seroprevalence of brucellosis, hematological, oxidative stress, and antioxidant enzymes in different breeds of cattle reared under tropical-desert conditions in Pakistan. This study comprised 570 cattle of different breeds. We recorded some epidemiological traits, including age and gender. The blood samples were obtained from all the cattle, screened with RBPT, and then confirmed by ELISA and PCR. The results recorded an overall 11.75%, 10.7%, and 9.64% prevalence of brucellosis based on RBPT, ELISA, and PCR. We obtained nonsignificant results in different age and sex groups of cattle. The results showed significantly (P ≤ 0.05) lower values of erythrocyte counts, hemoglobin quantity, hematocrit, lymphocytes, and monocytes in infected cases. The results showed that the total leukocyte and neutrophil cells significantly (P ≤ 0.05) increased. The lipid peroxidation parameters (MDA- and NO-scavenging activity of erythrocyte) increased significantly (P ≤ 0.05) in infected cattle, whereas significantly reduced antioxidant enzymes like SOD, RGSH, and CAT were. Similarly, significantly lower serum albumin levels and total serum proteins were recorded in infected cattle.

Evaluation of DNA Damage, Biomarkers of Oxidative Stress, and Status of Antioxidant Enzymes in Freshwater Fish (Labeo rohita) Exposed to Pyriproxyfen

Pyriproxyfen (PPF) mimics a natural hormone in insects and disrupts their growth. It is a well-known synthetic insecticide and aromatic juvenile hormone analog frequently used in agriculture and vegetable crops to control various insect species. At present, scanty information is available about the possible potential threats of PPF in aquatic organisms. Therefore, in this study, different toxico-pathologic endpoints of PPF like DNA damage, biomarkers of oxidative stress, and status of antioxidant enzymes were determined in Labeo rohita (freshwater fish). In our study, 60 active, free from any external obvious ailments, same size, age, and body mass were randomly allocated to four glass aquaria (T0-T3) separately containing 100 L water. The fish present in groups T1, T2, and T3 were administered PPF dissolved in water 300, 600, and 900 μg/L for 30 days. Different tissues including the blood and visceral organs were obtained from each fish on days 10, 20, and 30 of the experiment. Results on various morphological and nuclear changes in red blood cells of PPF-exposed Labeo rohita fish including pear-shaped erythrocytes, spherocytes, red blood cells with a blebbed nucleus, micronucleus, and nuclear remnants were significantly increased. Our results on genotoxicity (comet assay) recorded significantly (P ≤ 0.05) increased DNA damage in various tissues of insecticide-exposed fish. The results on oxidative stress profile (reactive oxygen species and thiobarbituric acid reactive substances) and antioxidant enzymes (reduced glutathione superoxide dismutase, peroxidase, and catalase) in multiple tissues of Labeo rohita fish concluded significantly (P ≤ 0.05) higher quantity of biomarkers of oxidative stress and lower concentrations of different antioxidant enzymes in treated fish. Hence, the findings of our experimental research determine that PPF could induce adverse toxic impacts on multiple tissues of Labeo rohita fish.

Acetochlor Affects Bighead Carp (Aristichthys Nobilis) by Producing Oxidative Stress, Lowering Tissue Proteins, and Inducing Genotoxicity

Acetochlor is persistently used in the agroproduction sector to control broadleaf weeds. Due to frequent and continuous applications, this herbicide can reach nearby water bodies and may induce deleterious changes in aquatic life. Therefore, investigation of harmful impacts of different environmental pollutants, including herbicides, is vital to knowing the mechanisms of toxicity and devising control strategies. The current experiment included bighead carp (n = 80) to estimate adverse impacts. Fish were randomly placed in 4 different experimental groups (T0-T3) and were treated for 36 days with acetochlor at 0, 300, 400, and 500 μg/L. Fresh blood without any anticoagulant was obtained and processed for nuclear and morphological changes in erythrocytes. At the same time, various visceral organs, including the gills, liver, brain, and kidneys, were removed and processed on days 12, 24, and 36 to determine oxidative stress and various antioxidant biomarkers. Comet assays revealed significantly increased DNA damage in isolated cells of the liver, kidneys, brain, and gills of treated fish. We recorded increased morphological and nuclear changes (P ≤ 0.05) in the erythrocyte of treated fish. The results on oxidative stress showed a higher quantity of oxidative biomarkers and a significantly (P ≤ 0.05) low concentration of cellular proteins in the gills, liver, brain, and kidneys of treated fish compared to unexposed fish. Our research findings concluded that acetochlor renders oxidative stress in bighead carp.