Effects of haloperidol on peripheral erythrocytes and brain neurotransmitter levels of juvenile African Sharptooth Catfish Clarias gariepinus.

OBJECTIVE: The study investigated the effects of haloperidol on peripheral erythrocytes and brain neurotransmitter levels of juvenile African Sharptooth Catfish Clarias gariepinus. METHODS: Juveniles were exposed to different concentrations of haloperidol (0.12, 0.24, and 0.48 mg/L) for 15 days and subsequently withdrawn from the drug for 5 days. Blood samples from the fish on days 1, 5, 10, and 15 and after the 5-day withdrawal period were analyzed for mutagenic changes, after which the fish were sacrificed. The brain was sampled for serotonergic and dopaminergic analyses. RESULT: There was formation of micronuclei in the peripheral fish blood, which increased as the duration and concentrations of the drug increased. The drug significantly reduced the serotonin activity but increased dopamine activity. Some of the studied parameters, however, recovered from the effects of the drug after the 5-day withdrawal period. CONCLUSION: Haloperidol is toxic to fish, and its use in the environment should be guarded to avoid adverse impacts on nontarget species like fish.

Haloperidol alters the behavioral, hematological and biochemical parameters of freshwater African catfish, Clarias gariepinus (Burchell 1822).

The presence of drugs and their metabolites in surface waters and municipal effluents has been reported in several studies, but their impacts on aquatic organisms are not yet well studied. The present study investigated the effects of exposure to the antipsychotic drug, haloperidol on the behavioral, hematological and biochemical parameters in juvenile Clarias gariepinus. The fishes were exposed to 0.12, 0.24 and 0.48 mg/L haloperidol for 15 days and later withdrawn from the toxicant and allowed to recover for 5 days. Blood was sampled on days 1, 5, 10, 15, and after the 5-day recovery for hematological and biochemical analysis. The pack cell volume (PCV), red blood cells (RBC), hemoglobin (Hb), reticulocytes and lymphocyte counts were significantly reduced in the exposed fish. The neutrophil counts were increased while that of monocytes, basophils and eosinophils were not affected by the drug. The mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were not different from the control on exposure to the drug. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and acid phosphatase (ACP); and serum creatinine, bile acid and bilirubin were increased on 15-day exposure to the drug. The activity of the clotting factor fibrinogen was reduced compared to the control after exposure to the drug. Haloperidol at concentrations used on 15-day exposure were toxic to fish, but the effect appeared short-lived, as it dissipated on 5-day withdrawal from the drug. While further studies are needed to ascertain the impact of prolonged exposure to environmentally relevant concentrations, caution is advised to avoid eco-toxicological damage to aquatic organisms.

Neuromodulatory and oxidative stress evaluations in African catfish Clarias gariepinus exposed to antipsychotic drug chlorpromazine.

Chlorpromazine (CPZ) is among the most famous drugs used for the treatment of psychosis such as delusions, hallucinations, schizophrenia, paranoia, or disordered thought in humans. In the present study, the acetylcholinesterase (AChE) activity and oxidative stress parameters in the brain of Clarias gariepinus juveniles exposed to CPZ were investigated. Fish were exposed to 0.53, 1.56, and 2.11 mg/L corresponding to 5, 10, and 20% of the 96 h LC50 of CPZ on C. gariepinus, respectively. The fish brain was sampled on days 1, 7, 14, and after 7-days recovery. Our results indicate that AChE values were significantly higher in exposed groups compared to the control on days 7, 14, and 7-days recovery. The values of lipid peroxidation (LPO), glutathione reductase (GR), and glutathione peroxidase (GPx) increased compared to the control while catalase (CAT) and superoxide dismutase (SOD) significantly declined at higher CBZ concentrations. While LPO and CAT returned to the same range as the control values after the 7-day withdrawal from the drug, AChE, SOD, GR, and GPx did not. The use and disposal of CPZ should be strictly regulated to avoid possible ecotoxicological impacts on non-target organisms.

Imidazole antifungal drug clotrimazole alters the behavior, brain acetylcholinesterase and oxidative stress biomarkers in African catfish Clarias gariepinus (Burchell 1822).

This study was carried out to determine the effect of clotrimazole (CTZ), an imidazole fungicide on behavior, brain acetylcholinesterase, lipid peroxidation and oxidative stress parameters in Clarias gariepinus juveniles. Fish were acutely exposed to five nominal concentrations of CTZ and control to assess the behavioral effects on fish. To determine the effects on brain acetylcholinesterase, lipid peroxidation and oxidative stress parameters, fish were exposed to three sub-lethal concentrations vis 7.76, 3.89 and 1.94 mg/L which corresponds to 20 10 and 5% of 96 h LC50 value of CTZ respectively and a control for 21 days and allowed to recover for 7 days. The brain, liver and gills were sampled weekly. Fish exposed to different concentrations of the drug displayed behavioral responses such as reduced swimming rate, mucus secretion, decrease in both the feeding frequency and rate. A duration dependent increase in the levels of brain acetylcholinesterase was observed among the exposed groups. The result of the sub-lethal exposure revealed concentration and duration significant increase in lipid peroxidation (LPO), catalase activity (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione reductase (GR) and glutathione peroxide (GPx) in both the liver and gill tissues of the exposed groups compared to the control. The effects of the drug on many of the observed parameters did not wane after the 7-day withdrawal period. This study revealed that CTZ has a negative impact on the observed parameters, thus providing additional evidence of its toxic effect on non-target aquatic species, especially fish.

Toxicity and genotoxic evaluations in African catfish Clarias gariepinus (Burchell 1822) exposed to Act Force Gold®, Butaforce®, and Atraforce®.

Act Force Gold®, Butaforce®, and Atraforce® are among the most commonly used pesticides in Nigeria. The lethal concentrations and the respective toxic units for the three pesticides were determined. The genotoxic effects of the three pesticides were investigated in the red blood cells of Clarias gariepinus using micronucleus (MN) assay. The 96 h LC50 was 4.75, 4.84, and 54.74 mg L-1 for Act Force Gold®, Butaforce®, and Atraforce®, respectively. The toxic units in ascending order of toxicity were 1.83, 20.66, and 21.05 for Act Force Gold®, Butaforce®, and Atraforce® respectively. The estimated safe levels based on NAS/NAE varied from 4.75 × 10-1-4.75 × 10-5 in Act Force Gold® through 4.64 × 10-1-4.85 × 10-5 in Butaforce® to 5.74-5.74 × 10-5 in Atraforce®. Fish specimens were exposed to the pesticides and sampling was done at regular intervals at days 1, 7, 14, and 21 and after another 7-day recovery period. The results obtained indicated concentration- and duration-dependent increase in % MN formation with maximum values of 3.40 ± 0.25 for Act Force Gold® on day 14 and 3.05 ± 0.36 and 2.35 ± 0.14 for Butaforce® and Atraforce® respectively on day 7 of exposure. The 7-day recovery period could not reverse the trend as the % MN values obtained were significantly different from the control. The results further support the use of MN assay in assessing the toxicity of aquatic pollutants and can be used in the monitoring of aquatic ecosystems.

Genotoxicity and Oxidative Stress Evaluations in Juvenile African Catfish Clarias gariepinus Exposed to NPK Fertilizer.

Juvenile African Catfish (also known as Sharptooth Catfish) Clarias gariepinus were exposed to 2.26, 4.52, and 11.30 mg/L NPK (15-15-15) fertilizer for 21 d followed by 7 d of recovery to assess the genotoxic effects of the fertilizer in erythrocytes. Biomarkers of oxidative stress were evaluated in the liver and gill tissues. The fertilizer induced micronuclei formation with maximum effects on day 7 in erythrocytes of individuals that were exposed to 4.52 and 11.30 mg/L NPK, and on day 14 in individuals exposed to 2.26 mg/L of the same fertilizer. The lipid peroxidation, glutathione reductase, and reduced glutathione values in the exposed fish increased, while the values of catalase, superoxide dismutase, and glutathione peroxidase decreased. There were mixed trends in the recovery patterns after the 7-d withdrawal from the fertilizer. Careful use of the fertilizer in the field is recommended to avoid toxicological effects on nontarget organisms.

Changes in Brain Acetylcholinesterase and Oxidative Stress Biomarkers in African Catfish Exposed to Carbendazim.

Carbendazim (CBZ) is a widely used, systemic, broad-spectrum benzimidazole fungicide. It is used worldwide against fungal diseases on a wide range of agricultural products and in domestic gardens. The activities of brain oxidative stress biomarkers and acetylcholinesterase (AChE) in juvenile African Catfish Clarias gariepinus exposed to CBZ were investigated. Juveniles were exposed to sublethal concentrations of 0.22, 0.43, and 0.64 mg/L CBZ, which corresponded to 5, 10, and 15% of the 96-h LC50 (the concentration that was lethal to 50% of the test organisms over the first 96 h) of CBZ fungicide for 21 d. Individuals were allowed an extra 7-d recovery period. The brain tissues were sampled and analyzed on days 1, 7, 14, 21, and 28 (including the 7-d recovery period). The results indicated significant concentration-dependent inhibition of the brain AChE activities in all exposed groups. The lipid peroxidation was significantly elevated while the antioxidant enzymes and protein values were significantly inhibited by CBZ exposure. However, the values of catalase on days 7, 14, and 21 were significantly higher than day 1 values. Overall, CBZ altered brain oxidative stress parameters and led to the inhibition of AChE. This fungicide should be used with utmost caution to protect and safeguard fish, ensuring that fish production and survival in the environment remain unaffected.

Genotoxicity assessment and oxidative stress responses in freshwater African catfish Clarias gariepinus exposed to fenthion formulations.

Fenthion is one of the most widely used organophosphate insecticides for the control of many varieties of pests in Nigeria. The genotoxic effect of the pesticide was evaluated in the blood erythrocytes of Clarias gariepinus using the micronucleus (MN) test. The oxidative stress parameters were also studied in the liver and gill tissues. Fish were exposed to 2.0, 4.0, and 8.0 mgL-1 of fenthion and sampling was done on days 1, 7, 14, 21 and after 7-day recovery. Micronuclei induction was highest (7.55) on day 14 at all concentrations in the peripheral blood cells. Oxidative stress was evidenced by increased lipid peroxidation (LPO). Maximum LPO values of 62.47% and 71.17% were observed in the gill and liver tissues respectively in C. gariepinus exposed to 8.0 mgL-1 concentration of fenthion. There were alterations in the values of reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) during the exposure and recovery periods. The 7-day recovery period was not adequate to eliminate fenthion-induced changes as LPO, CAT, and GR activity remain elevated. However, MN frequency and activity of SOD, GSH, and GPx (except at 8.0 mgL-1) recovered. The present findings give further credence on the integrated use of MN test and oxidative stress parameters in risk assessment of pollutants in aquatic ecosystem.

Subchronic Exposure to Fenthion Induces Hematological Changes in Liver Tissue of African Catfish Clarias gariepinus.

In this study, African Catfish (also known as Sharptooth Catfish) Clarias gariepinus were exposed to sublethal concentrations of fenthion of 2.0, 4.0, and 8.0 mg/L for 21 d and allowed to recover for 7 d to investigate the potential for hematological changes. Whole blood was sampled on days 1, 7, 14, and 21 postexposure and after a 7-d recovery period. During exposure, fenthion caused a reduction in red blood cell counts, hemoglobin concentration, and packed cell volume. There was an increase in white blood cell counts but no significant difference in mean corpuscular hemoglobin concentration, mean corpuscular volume, and mean corpuscular hemoglobin. Both increases and decreases were observed in white blood cell differentials. After the 7-d recovery period, both increases and decreases were observed in the hematological parameters. These results reveal that sublethal concentrations of fenthion can cause hematological alterations in African Catfish and that the substance should be used with caution. Received October 20, 2015; accepted May 4, 2016.

Short-Term Effects of Albendazole on the Oxidative Stress Markers and Hematological Parameters in Tissues of African Catfish Clarias gariepinus.

Albendazole (ABZ) is a typical broad-spectrum benzimidazole drug used for the treatment of parasitic worm infestations in humans and animals. The present study investigated the oxidative stress biomarkers and hematological parameters in juvenile African Catfish (also known as Sharptooth Catfish) Clarias gariepinus exposed to ABZ for 96 h. Fish were exposed to 0 (control) 20, 40, and 60 mg/L ABZ. The liver and gill tissues were sampled at regular intervals of 24 h, and the results showed significant concentration- and time-dependent increases in the values of lipid peroxidation but reductions in glutathione peroxidase, catalase, superoxide dismutase, and glutathione reductase in both tissues. Erythrocytes were sampled to evaluate hematological parameters. The results showed significant concentration- and time-dependent increases in white blood cells but no significant differences in mean cellular hemoglobin. Hemoglobin values, red blood cell counts, packed cell volume, mean cell volume, and mean cellular hemoglobin concentration decreased significantly over the experimental period. The activities of lymphocytes and neutrophils increased significantly, whereas there were no significant differences in basophils, eosinophils, and monocytes among the treatment groups. Albendazole should be used with caution, as sublethal concentrations induced oxidative stress in the liver and gill tissues along with hematological changes that were more evident in liver cells. Received November 20, 2015; accepted May 4, 2015.

Toxicological effects of carbosulfan in rats: Antioxidant, enzymological, biochemical, and hematological responses.

Carbosulfan is often used in agriculture for pest control on crops and for treatment against pyrethroid-resistant mosquitoes. This study investigated the impact of carbosulfan on oxidative stress markers, antioxidant defense, hematological, biochemical, and enzymological parameters in Sprague Dawley rats. Rats were orally administered carbosulfan doses of 1.02 to 10.20 mg/kg body weight daily; after 96 h, blood samples were taken, and the liver, kidney, and brain were dissected out for study. Results indicate that carbosulfan significantly increased the levels of lipid peroxidation and suppressed the activity of reduced glutathione, glutathione reductase, catalase, glucose-6-phosphate dehydrogenase, and adenosine triphosphatase. A mixed trend was observed in the activity of superoxide dismutase, while an increase was observed in the levels of serum uric acid, urea, aspartate aminotransferase, and alanine aminotransferase. Hemoglobin and albumin levels decreased but no significant differences were observed in creatinine and bilirubin levels. Future studies should include a more detailed analysis of the effects of chronic carbosulfan exposure on these biomarkers to further assess the impact of the pesticide on mammalian models.

Oxidative stress and biochemical responses in the tissues of African catfish Clarias gariepinus juvenile following exposure to primextra herbicide.

Primextra is a commercial herbicide formulation generally used in agriculture for weed control. The present study was designed to investigate the oxidative stress biomarkers and biochemical responses in the tissues of Clarias gariepinus juvenile exposed to primextra. Fish were exposed to 0.24 and 0.47 mgL(-1) corresponding to 1/20 and 1/10th of 96 h LC50 of the herbicide. The liver and muscle tissues were sampled on day 1, 5, 10 and 15 and results showed concentration and time dependent significant increase (p < 0.05) in the values of lipid peroxidation, glutathione peroxidase, catalase and alkaline phosphatase in both tissues. A marked significant increase (p < 0.05) was observed in the values of aspartate aminotransferase, alanine aminotransferase and glucose in the liver while a mixed trend in their values were observed in the muscle. The values of superoxide dismutase and protein in both tissues were comparable to the control except on day 15 in the liver where the values significantly declined. The condition factor was not directly affected but values of hepatosomatic index were significantly reduced. The present findings revealed that primextra induced toxic stress even at sublethal concentrations resulting in alterations of the studied parameters which were more evident in the fish liver than in the muscle tissue.

Induction of micronuclei and nuclear lesions in Channa punctatus following exposure to carbosulfan, glyphosate and atrazine.

The genotoxic effects of commonly used agricultural pesticides viz., carbosulfan, glyphosate, and atrazine, were evaluated in Channa punctatus (Pisces, Perciformes) using micronucleus (MN) test and induction of nuclear lesions (NL). The 96 h LC50 value were estimated by probit analysis as 0.27, 32.0 and 42.0 mg L(-1), respectively, for carbosulfan, glyphosate, and atrazine using semi-static bioassays. Based on these values, three sublethal test concentrations of carbosulfan (0.07, 0.13, 0.20 mg L(-1)), glyphosate (8.1, 16.3, 24.4 mg L(-1)) and atrazine (10.6, 21.2, 31.8 mg L(-1)) corresponding to », ½ and ¾ of the LC50 of the pesticides respectively, were selected for exposure for 96 h. Peripheral blood samplings were taken at intervals of 24 h for assessment of MN and NL frequencies. Considerably higher genotoxic damage was induced by carbosulfan as compared to glyphosate and atrazine. There were significant effects (p < 0.01) of concentrations in all the treated groups. The induction of MN and NL was highest at 96 h pesticide exposure at all test concentrations. The nuclear abnormalities recorded in this study, such as blebbed-, lobed-, notched- and bi-nuclei, other than micronuclei, are indicators of genotoxic damage.

Changes in behavior and hematological parameters of freshwater African catfish Clarias gariepinus (Burchell 1822) following sublethal exposure to chloramphenicol.

The present study was aimed at evaluating the effects of different concentrations of the most commonly used fish antimicrobial drug, chloramphenicol (CAP), on the behavior and hematological parameters of Clarias gariepinus. Fish specimens were exposed to three (2.5, 5.0 and 10.0 mg L(-1)) sublethal concentrations of CAP and a control. Abnormal behavioral changes were observed in fish exposed to higher concentration of CAP. Blood erythrocytes were sampled on days 1, 5, 10 and 15 postexposure to evaluate hematological parameters. Results showed concentration- and time-dependent significant increase in packed cell volume after day 5 of exposure (p < 0.05). Hemoglobin values also significantly decreased from day 5, whereas values of mean cellular volume significantly decreased throughout the experimental period (p < 0.05). A mixed trend was observed in the mean values of red blood cells, white blood cells, mean cellular hemoglobin and mean cellular hemoglobin concentration as well as neutrophils. Activities of lymphocytes were significantly increased in all CAP-treated fish during the exposure period, whereas no significant differences were observed in values of monocytes, eosinophils and basophils among the treatment groups and control. Consequently, precautions must be taken, especially when high concentrations of CAP are used in long-term treatments of C. gariepinus in aquaculture.