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.

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.