Cyto-histopathological Alterations in the Liver of Azadirachtin Treated Catfish, Heteropneustes fossilis

In the present study, impact of the plant pesticide, azadirachtin was assessed on cyto-histopathology of the liver of freshwater catfish, Heteropneustes fossilis . The fishes were treated with 20 % of 96-h LC 50 value of azadirachtin i.e. 10.47 mg L −1 for 4 weeks. Six fishes were sacrificed after 1, 2, 3, and 4 weeks following the treatment. Liver tissues from the fishes were fixed, routinely processed and stained for microscopic studies, and histopathological alterations were assessed. The liver of 1 week azadirachtin exposed fish exhibited enlarged nuclei and degranulation of the cytoplasm of a few cells. After 2 weeks exposure the arrangement of hepatocytes disrupted. A few hepatocytes exhibited vacuolization and pycnotic nuclei. Following 3 and 4 weeks of treatment, more hepatocellular necrosis was observed. At places, focal necrosis and fatty degeneration was observed. Within sinusoids increased lymphocytes were noticed. It can thus be concluded that hepatic alterations as the result of botanical pesticide exposition of fish may serve as a sensitive biomarker for the toxicity of sublethal biopesticide concentrations. However, for a better understanding of liver impairments caused by biopesticides, more studies are needed. Graphical Abstract