Evaluation of hemato-biochemical, antioxidant enzymes as biochemical biomarkers and genotoxic potential of glyphosate in freshwater fish (<i>Labeo rohita</i>)

Abstract

Glyphosate, an herbicide is extensively used in aquaculture and agriculture to control unwanted weeds, the exact mechanism of its toxicity in freshwater fish is not exactly understood. Therefore, the current study examined the mechanisms of toxicity of glyphosate in Labeo rohita. Labeo rohita were randomly divided into five groups and were exposed to glyphosate. Glyphosate-treated fish exhibited clinical and behavioural ailments. Microscopically, different gills of exposed fish indicated necrosis of epithelial cells of the primary and secondary lamellae, congestion, atrophied lamellae, and uplifting of lamellae. Kidneys and livers of intoxicated fish exhibited different degenerative abnormalities. Red blood cells, haemoglobin concentration, lymphocytes, and monocytes count decreased significantly (p < 0.05) while biomarkers of liver and kidneys increased significantly in treated fish at higher doses. Values of various biochemical parameters of liver, kidneys, and gills tissues in treated fish including generation of ROS increased significantly while total proteins, antioxidant enzymes catalase, reduced GSH, and SOD significantly (p < 0.05) decreased in time and a dose-dependent manner. Comet and micronucleus assays showed an increased frequency of DNA damage. In conclusion, results indicated that glyphosate induces toxicity via physiological and chemical disturbances in different tissues of fish in a dose and time response.