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Longitudinal Sections of control fish gills (a), exposed (b-f) and recovery (g and h) (H&E, X400). (a) Showing Blood Capillary (BC), Pavement Cells (PV), Pillar Cells (PC), Mucous Cells (MC), Primary Lamellar Epithelium (PLE), and Secondary Lamellae (SL). (b) Showing aneurism (A) in many areas of secondary lamellae with Collapse (C) of the ladder-like arrangement of the (pillar cell-blood capillary) system, subepithelial edema (E), epithelium lifting (L), hyperplasia of interlammellar epithelium (HYP), Curling of secondary lamellae (CU), necrosis of the epithelial cell (N) and hypertrophy and proliferation in the erythrocytes of cartilaginous core (HPC). (c) Showing hyperplasia of the epithelial cells (HYP), Collapse (C) of the ladder-like arrangement of the (pillar cell-blood capillary) system with vacuoles (Va). Subepithelial edema (E), epithelium lifting (L) and curling of secondary lamellae (CU), necrosis (N) of the epithelial cells. Desquamation in respiratory wall (DRW) with rupture (R) of this wall. (d) Showing bifurcation of filament (BF), hyperplasia of the epithelial cells (HYP) with collapse (C) of the ladder-like arrangement of the (pillar cell-blood capillary) system. Fusion (F) and curvatures (CU) of the secondary lamellae. Subepithelial edema (E), lifting (L) of epithelial layer. Desquamation in respiratory wall (DRW). (e) Showing hyperplasia of the epithelial cells (HYP) and collapse (C) of the ladder-like arrangement of the (pillar cell-blood capillary) system while other lamellae showed epithelial rupturing (R). Hypertrophy (HYT) in the mucous cell and pavement cells (PV). Reduced in size in the pillar cells (PC) and curvatures (CU) of the secondary lamellae. (f) Showing hyperplasia (HYP) of the epithelial cells and aneurysm (A). Collapse (C) of the ladder-like arrangement of the (pillar cell-blood capillary) system. Congested blood (CB) with lymphocytic aggregation (LA). Hypertrophy (HYT) of 2nd gill lamellae, subepithelial edema (E), lifting (L) and curvatures (CU). (g) Showing normal structure with small lamellar aneurysm (A) and curling of secondary lamellae (CU). (h) Showing the gill tissue showed clear improvement with small curvatures (CU) in the secondary lamellae.
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This study investigates the effects of silver nanoparticles (AgNPs) and silver nitrate (AgNO3) on gills and muscles in African catfish (Clarias garepinus). Changes in bioaccumulation, histopathological, and histochemical were used as biomarkers. The effects of AgNPs were recorded in some of these properties based on their size (20 and 40 nm) and th...
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... Cells (MC) and Pavement Cells (PV) are found in the filament epithelium and at the base of lamellae, but they lack mild cytoplasm and are smaller than chloride cells. The gill filaments are covered with squamous Pavement Cells (PV) ( Fig. 1 a). The application of the alcian blue plus reaction with periodic acid sheif (AB-pH 2.5 & PAS) provided a small number of mucous secreting cells at the base of the secondary lamellae (purple color of neutral polysaccharide and blue color of acid mucosubstance) and a distinct basement membrane ( Fig. 2 a). ...
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... of secondary lamellae followed by necrosis of the epithelial cell was reported. Moreover, hypertrophy and proliferation within the erythrocytes of cartilaginous center was noticed ( Fig. 1 b). Recovery period for 15 days, the gill tissue retained its normal structure with some alterations such as lamellar aneurysm and curling of secondary lamellae ( Fig. 1 g and h). ...
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... hypertrophy and proliferation within the erythrocytes of cartilaginous center was noticed ( Fig. 1 b). Recovery period for 15 days, the gill tissue retained its normal structure with some alterations such as lamellar aneurysm and curling of secondary lamellae ( Fig. 1 g and h). Such effects are reflected in terms of semiquantitative assessments of the histopathology of the exposed gills AgNO 3 of C. gariepinus ( Tables 2 and 3 ). ...
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... and rupture in respiratory wall (pavement cells of the 2nd lamellae). Increase in number and size of mucus secreting cells in the interlamellar epithelium ( Fig. 1 c). Recovery period for 15 days, enhancement in the gills tissue was observed with some alterations ( Fig. 1 g and h). ...
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... in number and size of mucus secreting cells in the interlamellar epithelium ( Fig. 1 c). Recovery period for 15 days, enhancement in the gills tissue was observed with some alterations ( Fig. 1 g and h). The semiquantitative assessments of the histopathology have been reported in exposed gills of C. gariepinus ( Tables 2 and 3 ). ...
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... and curvatures of the secondary lamellae and subepithelial edema were seen within the secondary platelets that led to lifting of epithelial layer. Also, desquamation and rupture of respiratory wall (pavement cells of the 2nd lamellae) ( Fig. 1 d). Recovery period for 15 days, enhancement in the gill tissues was observed with the secondary lamellae curvatures ( Fig. 1 g and h).The semiquantitative evaluation of the histopathology tissue has been reported in the exposed gills of C. gariepinus ( Tables 2 and 3 ). ...
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... desquamation and rupture of respiratory wall (pavement cells of the 2nd lamellae) ( Fig. 1 d). Recovery period for 15 days, enhancement in the gill tissues was observed with the secondary lamellae curvatures ( Fig. 1 g and h).The semiquantitative evaluation of the histopathology tissue has been reported in the exposed gills of C. gariepinus ( Tables 2 and 3 ). ...
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... addition, hypertrophy of mucous cell and pavement cells was observed. Moreover, the pillar cells appeared much reduced in size and marked curvatures of the secondary lamellae were observed ( Fig. 1 e). Recovery period for 15 days, improvement in the gill tissues with hyperplasia of the epithelial cells was observed ( Fig. 1 g and h). ...
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... the pillar cells appeared much reduced in size and marked curvatures of the secondary lamellae were observed ( Fig. 1 e). Recovery period for 15 days, improvement in the gill tissues with hyperplasia of the epithelial cells was observed ( Fig. 1 g and h). The semiquantitative evaluation of the histopathology in exposed gills of C. gariepinus was observed ( Tables 2 and 3 ). ...
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... blood in the secondary lamellae with distinct lymphocytic aggregation was recorded. Moreover, extensive hypertrophy of 2 nd gill lamellae and subepithelial edema that led to epithelium lifting and curvatures in the secondary lamellae was observed ( Fig. 1 f). Recovery period for 15 days, the gill tissues showed a marked improvement with small curvatures in the secondary lamellae ( Fig. 1 g and h). ...
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... extensive hypertrophy of 2 nd gill lamellae and subepithelial edema that led to epithelium lifting and curvatures in the secondary lamellae was observed ( Fig. 1 f). Recovery period for 15 days, the gill tissues showed a marked improvement with small curvatures in the secondary lamellae ( Fig. 1 g and h). The semiquantitative assessments of the histopathology were observed in exposed gills of C. gariepinus ( Tables 2 and 3 ). ...
Citations
... Harris's hematoxylin and eosin (H&E) stain was used to visualize tissue structure (Bancroft and Gamble, 2008) and the Masson's trichrome (Foot, 1933) method was used to detect the presence of tissue fibrosis. For scoring each histopathological parameter, six sections of four fish from each treatment were randomly chosen and labelled as follows: control, -unchanged (0-2); mild, + (>2-10%) area of section; moderate, ++ (>10-40%) partition area; and severe, +++ (>40% partition area) (Sayed et al., 2020b;Hamed et al., 2021b). Sections were examined under an Olympus microscope (model BX50F4, Olympus Optical Co., Ltd., Tokyo, Japan) ( × 400). ...
Pyrogallol is a naturally occurring polyphenol derived from natural plants, such as Acer rubrum and Eucalyptus sp. The current study was designed to evaluated pyrogallol-mediated toxicity at sublethal levels (1, 5, and 10 mg/L), derived from 96h-LC50 values previously determined for African catfish (Clarias gariepinus). Immunotoxicological indices, histological, histochemical, and ultrastructural alterations in C. gariepinus were evaluated following a 15-day pyrogallol exposure. Pyrogallol decreased immune parameters [lysozyme activity (LYZ), immunoglobulin M (IgM), and phagocytic activity] and increased pro-inflammatory cytokines, interleukin-1 beta (IL-1β), interleukin-6 (IL-6) in the serum of C. gariepinus. In addition, histopathology analysis demonstrated that exposure to pyrogallol induced injury in the liver and spleen of fish. Cellular changes in the liver include hepatocyte hydropic degeneration, melanomacrophage, vacuolated hepatocytes, congested blood, severe structural deformation, and haemorrhage. In the spleen, ellipsoid structures, melanomacrophage centres, and infiltration of inflammatory cells were evident. Together, a high frequency of histopathological lesions was scored in both the liver and spleen of C. gariepinus, which showed a dose-dependent relationship between pyrogallol exposure and histopathological indices. Our data suggest that dysfunction in the immune system may be mediated by pyrogallol-induced changes in cytokines.
... Further, silver residues showed the highest levels in gills compared to other tissues in common carp and African catfish (C. gariepinus) [22,123]. Such variations may depend on species-specific differences or variable experimental conditions. ...
Recently, nanotechnology has become an important research field involved in improving animal productivity, including aquaculture. In this field, silver nanoparticles (AgNPs) have gained interest as antibacterial, antiviral, and antifungal agents. On the other hand, their extensive use in other fields increased natural water pollution causing hazardous effects on aquatic organisms. Quercetin is a natural polyphenolic compound of many plants and vegetables, and it acts as a potent antioxidant and therapeutic agent in biological systems. The current study investigated the potential mitigative effect of quercetin nanoparticles (QNPs) against AgNPs-induced toxicity in Nile tilapia via investigating the liver function markers, hepatic antioxidant status, apoptosis, and bioaccumulation of silver residues in hepatic tissue in addition to the whole-body chemical composition, hormonal assay, intestinal enzymes activity, and gut microbiota. Fish were grouped into the control, fish exposed to 1.98 mg L–1 AgNPs, fish that received 400 mg L–1 QNPs, and fish that received both QNPs and AgNPs at the same concentrations for 60 days. The moisture and ash contents of the AgNP group were significantly higher than those of the other groups. In contrast, the crude lipid and protein were decreased in the whole body. AgNPs significantly increased serum levels of ALT, AST, total cholesterol, and triglycerides and decreased glycogen and growth hormone (***P < 0.001). The liver and intestinal enzyme activities were significantly inhibited (***P < 0.001), while the oxidative damage liver enzymes, intestinal bacterial and Aeromonas counts, and Ag residues in the liver were significantly increased (***P < 0.001, and *P < 0.05). AgNPs also significantly upregulated the expression of hepatic Hsp70, caspase3, and p53 genes (*P < 0.05). These findings indicate the oxi-dative and hepatoxic effects of AgNPs. QNPs enhanced and restored physiological parameters and health status under normal conditions and after exposure to AgNPs.
... Rahmani et al. observed changes in the gill such as oedema, aneurism, hyperplasia, dilated and clubbed tips, rapid increase in the erythrocytes of the cartilaginous core, a fusion of lamellae, curvature, and mucous secretion increase when the zebrafish (Danio rerio) was exposed to Ba and Cr doped TiO 2 -NPs [59]. Similar observations were also made on the gills of the African catfish (Clarias garepinus) after exposure to Ag-NPs [60] and they are associated with the organism's defense mechanism. Some of the current histopathological analyses (studied between 2020 and 2022) of fish are shown in Table 1. ...
Engineered nanoparticles (ENPs) have gained attention in the world of technology due to their diverse and unique properties compared to their pristine counterparts. Their tunable physical, chemical, and biological properties make them applicable in various fields including the environment, agriculture, and medicine or biotechnology. Consequently, there is a rapid increase in ENPs waste in the environment. This raises questions about what will become of the waste and the potential environmental toxicity and health risks. Knowledge of their fate in the environment helps control/manage their usage mostly taking advantage of the initiatives of the circular economy (reuse, reduce and recycle). In this review, the fate of ENPs in aquatic systems is highlighted. Different ENP transformations in aquatic systems are explained. Additionally, uptake, internalization, and toxicity in fish are elaborated together with some toxicity mechanisms. Finally, the biomagnification of these ENPs up the food chain is illustrated considering that fish are a good source of nutrients and play a major role in addressing food security issues worldwide. The information used in this review was obtained mostly from published articles (obtained through google scholar) and other internet sources with the keywords being ENPs transformation in natural aquatic systems, ENP toxicity to fish, mechanism of ENP toxicity to fish, and bioaccumulation of ENPs in fish.
... 33 For example, when juvenile zebrafish were exposed to nitrate for a long time, gill filaments were damaged by defensive reactions, including oedema, hemorrhages, hyperplasia of epithelial cells, and necrosis. 34 In the presence of silver nanoparticles, the gills of African catfish showed some direct damage and damage caused by defense reactions, such as subepithelial edema, epithelial bulge, interlayer epithelial hyperplasia, epithelial cell necrosis, and secondary lamellar curl. 35 In this study, gill epithelial cell proliferation and edema appeared in the fish gills of all treatments, while more serious injuries, such as lamellar fusion and necrosis, were observed with exposure to 3000 mg/L sulfate. ...
Sulfur-based materials are widely used as electron donors for denitrification to enhance nitrogen removal from water. This leads to an increased sulfate concentration in the effluent or sulfate accumulation in recirculating aquaculture systems. This study explored acute and chronic toxicity of sulfate to juvenile zebrafish (Danio rerio) and investigated the histopathological changes in the gills of juvenile zebrafish exposed to sulfate. Results show that zebrafish had a high tolerance to sulfate, with no acute toxicity at sulfate concentrations from 250 to 3200 mg/L. For the chronic toxicity study, it was found that zebrafish mortality decreased with the increase in sulfate concentrations ranging from 250 to 1500 mg/L. In contrast, when the sulfate concentration was 1500-3000 mg/L, zebrafish mortality increased with the increasing sulfate concentration. In addition, in the ion balance test, KCl was added to balance the effects of Na+ from the Na2SO4 used to obtain the desired sulfate concentrations, showing that fish mortality correspondingly increased with increasing KCl addition. Furthermore, when living in an environment with elevated sulfate concentrations for a long period, changes were observed in the morphology, behavior, and gill tissue of the zebrafish, including slow and lateral swimming; bottom settling; and large opening and closing, lamellar fusion, and necrosis of gills. This research reveals the toxicity of sulfate to aquatic organisms, providing a scientific basis for the promotion and application of sulfur or sulfur-based materials in autotrophic reduction processes for wastewater treatment.
... The small sizes of NPs allows its easy penetration through the cell membranes of animals and plants which could effectively cause genotoxicity. Studies on aquatic organisms and fisheries had shown that NPs can promote higher production of reactive oxygen species and free radicals due to its intrinsic chemical reactivity, the production of the aforementioned radicals could result into numerous toxicities such as proteins denature, DNA mutation, production of inflammation, oxidative stress and cell death [281,282]. In agriculture, the usage of NPs derived pesticides and fertilizers could cause environmental pollution such as soil pollution and water pollution when been carried to the water bodies by wind, erosion or flood. ...
The applications of NPs in agriculture is a crucial tool for modern-day effective agricultural practice. NPs have been noted
for efficient stimulation of plant growth, preservation of crops against precarious diseases, promotion of crop quality and
yield, packaging material for farm products, vaccination of fishes and other farm animals. The goal of sustainable farming
can be achieved by exploring the importance of NPs in developing agricultural practices to meet the demand for food and
agricultural product across the globe without any threat to the environment and human. This review aims to advance our
understanding about several importance of NPs in fishery, crop production and preservation. It provides a holistic view on the
usefulness of NPs in multiple aspects of agriculture, from the synthesis of nanoparticles to prevent crops from pest, prevent
agricultural products from spoilage and provision of nutrients to crops throughout their life span. It also drives toward the
qualitative and quantitative increase in the yield of agricultural products. The route for the proper synthesis and characterization
of nonhazardous NPs with efficient yield was comprehensively discussed.
... The increased HAI values and MAV observed at 8 and 10 g·L −1 NaCl exposure were mainly associated to marginal gill canal dilation and lamellar epithelium hyperplasia, respectively. These changes may indicate pirarucu sensitivity to NaCl, although they were reversible, returning to normal when the stressor agent was removed from the environment (Sayed et al. 2020). ...
The aim of the present study was to assess the use of sodium chloride (NaCl) against monogenoid trematodes infestations in pirarucu (Arapaima gigas). Two assays were conducted with pirarucu juveniles, the first comprising an in vitro exposure to 8, 9, 10, and 11 g·L−1 NaCl and the second, in vivo exposure test to NaCl at the same concentrations. The best in vitro results were observed for 1-h exposures at 9, 10, and 11 g·L−1 NaCl, resulting in 60% and 100% parasite mortality, respectively. In vivo exposures to 8 and 10 g·L−1 NaCl were 36 and 22% efficient, respectively, following 2 h of exposure, with no mortality. Some dose-dependent changes were observed in exposed fish, such as decreased hemoglobin and MCHC values at the highest NaCl concentration compared to the other NaCl concentrations and the control group. Most frequent gill tissue alterations observed were capillary dilatation and mucus secretions compared to the control group at the highest NaCl concentrations (10 and 11 g·L−1). Decreased mean (p < 0.05) water pH values and increased mean electrical conductivity were noted compared to the control group. In conclusion, our findings suggest that NaCl exhibits low toxicity toward pirarucu without physiological alterations and anthelmintic activity to the monogenoid directly influenced by exposure time and concentration. Moreover, 100% of the monogenoids present in the gills of the fish were identified as Dawestrema cycloancistrium.
... Uncited references [90][91][92][93][94][95][96][97][98][99][100] Declaration of Competing Interest ...
In the present study, the neutral comet assay was applied for determination DNA double strand breakage in the African catfish Clarias gariepinus exposed variable concentrations and size of silver nanoparticles and ions. The parameters, tail % DNA; tail length, tail area; tail intensity; tail moment, olive tail moment, head mean intensity exhibited variability in the treatment and recovery periods. The silver small sized nanoparticles affect significantly (P < 0.0001) all the comet parameters in comparison to other treatments. In the case of recovery, the high sized nanoparticles with high concentration exhibited the significant effects in all parameters in comparison to other treatments. Moreover, correlation between exposure and recovery periods for each parameter was found to be significantly lower (P < 0.05). A positive insignificant correlation (R = 0.79) was recorded between % TDNA of the exposure period and erythrocyte alterations of the same period. On the other hand, such %TDNA was positively correlated (0.81-0.96) with more biochemical and histopathological parameters and negatively correlated (-0.85-0.88) with some other parameters. No micronuclei were recorded in association with AgNPs or Ag-induced DNA damages and other erythrocytes alterations. DNA damage was identified as follows: undamaged (%TDNA 0-10%), low damaged (%TDNA >10-20%), moderate damaged (%TDNA ≥20-40%) and sever damaged (%TDNA ≥ 40%). The undamaged DNA exhibited more or less decline with Ag and AgNPs whereas the damaged DNA increased with fluctuation especially with Ag and all concentration of AgNPs except for 40 nm/100 µg/L. After 15-day recovery, fluctuation in undamaged and damaged DNA was evident due to insufficient period of DNA repair with individual variations. No hedgehogs (%TDNA <85%) were recorded in both periods of exposure and recovery since low percent of severe damage was recorded. These findings emphasize on the adverse impacts of AgNPs especially those of small size and/or of high concentration on fishes. © 20XX
... The main effects observed in fishes exposed to NPAg are silver accumulation in various tissues, such as gills, liver, muscle (Johari et al., 2015;Sayed et al., 2020), and brain (Bacchetta et al., 2017), induction of metallothioneins , in addition to the increased production of reactive oxygen species (ROS) and consequent oxidative stress (Ale, Bacchetta, et al., 2018). Changes in enzymes involved in osmoregulation (Xiang et al., 2020), neurotoxicity (Devi et al., 2015;Zhao et al., 2019), reductions in the number of erythrocytes, and hyperglycemia (Ibrahim, 2020) are also commonly observed. ...
Biogenic silver nanoparticles (bNAg) have been suggested as a less toxic alternative to ionic silver (Ag), and also a more ecological alternative to synthetic silver nanoparticles (sNAg). However, the differences between the sublethal effects caused by bNAg and silver nitrate (AgNO3) are hardly known, especially in native fishes of the Neotropical region. Most researchers have only compared the effects of sNAg and AgNO3. Thus, the objective of this work was to evaluate the effects of bNAg, produced by the fungus Fusarium oxysporum, and to compare these with the effects of AgNO3 in the Neotropical fish Prochilodus lineatus. The animals were exposed for 24 and 96 h at nominal concentrations of 10 and 25 µg L⁻¹ of Ag. At the end of the exposures, Ag accumulation, metallothionein concentration, hematological parameters, plasma glucose and ion concentrations, activity of the main ATPases and carbonic anhydrase in the gills, enzymatic and non-enzymatic antioxidants, lipid peroxidation, and neurotoxic effects were evaluated. Both bNAg and AgNO3 caused Ag accumulation in the blood, gills, and brain, in addition to neurotoxic effects on muscle, alterations in reduced glutathione concentration in the gills, and increased glutathione-S-transferase activity in the liver. Hyperglycemia, ionic imbalances, and alterations in the activity of ion transport enzymes in the gills were also observed. As the effects of bNAg were similar to the effects of AgNO3, it is concluded that animals exposed to the highest concentration of silver were the most affected, regardless of the form of silver used in the exposure medium.
... This increase in metabolic activity has been already described as part of the processes aimed to cope with pollutant insult [65]. However, another possible explanation is related with the increased distance between the polluted outer media and the bloodstream after the exposure of fish to metals (Cr, Cd, Cu, Zn, Ag NPs) in vivo as a result of gill hyperplasia, a phenomenon occurring when gill cells divide in response to stress [27,[66][67][68]. ...
Determination of acute toxicity to vertebrates in aquatic environments is mainly performed following OECD test guideline 203, requiring the use of a large number of fish and with mortality as endpoint. This test is also used to determine toxicity of nanomaterials in aquatic environments. Since a replacement method for animal testing in nanotoxicity studies is desirable, the feasibility of fish primary cultures or cell lines as a model for nanotoxicity screenings is investigated here. Dicentrarchus labrax primary cultures and RTgill-W1 cell line were exposed to several concentrations (0.1 to 200 ug/mL) of different nanoparticles (TiO2, polystyrene and silver), and cytotoxicity, metabolic activity and reactive oxygen species formation were investigated after 24 and 48 h of exposure. Protein corona as amount of protein bound, as well as the influence of surface modification (-COOH, -NH2), exposure media (Leibovitz’s L15 or seawater), weathering and cell type were the experimental variables included to test their influence on the results of the assays. Data from all scenarios was split based on the significance each experimental variable had in the result of the cytotoxicity tests, in an exploratory approach that allows for better understanding of the determining factors affecting toxicity. Data shows that more variables significantly influenced the outcome of toxicity tests when the primary cultures were exposed to the different nanoparticles. Toxicity tests performed in RTgill-W1 were influenced only by exposure time and nanoparticle concentration. The whole data set was integrated in a biological response index to show the overall impact of nanoparticle exposures.
Triclosan (TCS), an antimicrobial additive in various personal and health care products, has been widely detected in aquatic environment around the world. The present study investigated the impacts of TCS in the gills of the fish, Cyprinus carpio employing histopathological, biochemical, molecular docking and simulation analysis. The 96 h LC50 value of TCS in C. carpio was found to be 0.968 mg/L. Fish were exposed to 1/1000th (1 µg/L), 1/100th (10 µg/L), and 1/10th (100 µg/L) of 96 h LC50 value for a period of 28 days. The histopathological alterations observed in the gills were hypertrophy, hyperplasia, edematous swellings, and fusion of secondary lamellae in TCS exposed groups. The severity of these alterations increased with both the concentration as well as the duration of exposure. The present study revealed that the activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase, glutathione peroxidase, and reduced glutathione content decreased significantly (p < 0.05) in both concentration and duration dependent manner. However, a significant (p < 0.05) increase in the activity of the metabolic enzymes such as acid phosphatase and alkaline phosphatase was observed in all three exposure concentrations of TCS from 7 to 28 days. The activity of acetylcholinesterase declined significantly (p < 0.05) from 7 to 28 days whereas the content of acetylcholine increased significantly at the end of 28 day. The experimental results were further confirmed by molecular docking and simulation analysis that showed strong binding of TCS with acetylcholinesterase enzyme. The study revealed that long-term exposure to sublethal concentrations of TCS can lead to severe physiological and histopathological alterations in the fish.
