Hepatotoxic effects of malathion on the freshwater African catfish, Clarias gariepinus

The present study was aimed to investigate the impact of malathion on the biochemical and histological parameters of African freshwater catfish, Clarias gariepinus. Ethical permission was taken from the IAEC, and the experiment was conducted according to the CPCSEA guidelines for animal handling. During this study, fish were divided into three groups. The first group served as a control, the second group was treated with a low dose (400µg/L) of malathion, and the third group was treated with a high dose (800µg/L) of malathion for 10 days. The results of the study exhibited alterations in the biochemical parameters and histopathology of the liver. Biochemical constituents such as protein and carbohydrate concentration in the liver of fish treated with 400µg/L and 800µg/L of malathion decreased as compared to the control. The histopathological structure of the liver exposed to 400µg/L malathion for 10 days indicated toxic lesions such as enucleated hepatocytes, degeneration of the central vein, infiltration of erythrocytes, and pycnotic nuclei, whereas the liver exposed to 800µg/L malathion for 10 days showed irregular-shaped hepatocytes, binucleated hepatocytes, melanomacrophage necrosis, reduced central vein, and sinusoidal dilation. Thus, it may be concluded that malathion significantly altered the biochemical constituents of the liver and deteriorated the histological structure, which in turn altered the metabolic functions of the liver.