Effects of Exposure to Cypermethrin and Thiourea on Redox Status, Activities of Phosphatases and Digestive Enzymes, and Intestinal Histopathology in African Catfish, Clarias gariepinus

• Published in: Inland water biology 2021-07, Vol.14 (4), p.461-468
• Main Author: Adeyemi, Joseph A.
• Format: Article
• Language: English
• Subjects: Acid phosphatase; Agrochemicals; Alkaline phosphatase; Aquatic Toxicology; Biodiversity; Biomedical and Life Sciences; Catfish; Clarias gariepinus; Crop yield; Cypermethrin; Digestive enzymes; Disintegration; Enzymes; Exposure; Fish; Freshwater & Marine Ecology; Freshwater fishes; Geoecology/Natural Processes; Glutathione; Histopathology; Intestine; Intestines; Lamina propria; Life Sciences; Mucosa; Muscles; Oxidoreductions; Pest control; Phosphatase; Renewal; Thiourea; Thioureas; Toxicants; Toxicity; Toxicology
• ISSN: 1995-0829; 1995-0837
• DOI: 10.1134/S1995082921040027

Agrochemicals including cypermethrin (cyp) and thiourea are increasingly being applied in modern agriculture, for pest control and to improve crop yield. However, their usage often results in serious environmental concerns. In this study, juvenile African catfish Clarias gariepinus (Burchell 1822) were exposed to 50 µg/L cyp, 100 µg/L cyp, 0.05% thiourea, 50 µg/L cyp + 0.05% thiourea or 100 µg/L cyp + 0.05% thiourea, in a static renewal for 3 weeks, after which the fish were sacrificed, and the level of reduced glutathione and activities of acid phosphatase, alkaline phosphatase, amylase, protease and lipase were determined in the liver or intestinal homogenates. Also, the histopathology of some sections of the intestine was performed. The control fish were maintained in uncontaminated water (i.e. not exposed to cypermethrin or thiourea). The individual exposure of fish to cypermethrin and thiourea resulted in a significant decrease in the levels of GSH and the activities of most of the enzymes. These effects were more pronounced in fish that were exposed to cypermethrin and thiourea under a co-exposure scenario. The histological analyses of some sections of the intestine also revealed the toxicological effect of these agrochemicals, and their use led to visible intestinal pathologies such as severe erosion of the mucosa layer, faded lamina propria and disintegration of the muscle layer. The results of this study demonstrate that both cypermethrin and thiourea can alter the redox status and nutritional physiology of fish. The greater toxic effects of cypermethrin and thiourea under the co-exposure condition reiterated the potential for interactions and synergistic relationship among toxicants.