Biochemical and genotoxic effects of some pesticides on the Egyptian Toads, Sclerophrys regularis (Reuss, 1833)

The effect of the 1/10 the application rates of either copper sulfate, temephos, glyphosate, or bifenthrin on some biochemical and genotoxic markers of the Egyptian toads, Sclerophrys regularis, exposed for 96 h under conditions similar to the real situation was investigated. The results illustrated that, brain acetylcholinesterase (AChE) was significantly inhibited following temephos treatment, while the enzyme activities markedly increased following either glyphosate or bifenthrin exposure. Liver glutathione-S-transferase (GST) activity was inhibited following either copper sulfate or bifenthrin, while the activity increased following glyphosate treatment. Also, the data illustrated that, The level of glutathione reduced (GSH) in liver and the activities of lactic dehydrogenase (LDH), transaminasaes (AST and ALT), and phosphatases (ACP and ALP) in liver and serum showed significant increases following all the treatments and bifenthrin was the potent one. Regarding the genotoxicity of the tested pesticides, the number of structural aberrations induced by the different treatments was enumerated in the present study. It was found that all the tested pesticides significantly increased either the frequency of abnormalities or the number of polychromatic erythrocytes (PCE) per 1000 cells (the frequency of micronucleus, MN) compared to the negative control, where bifenthrin and temephos were found to be more potent than cyclophosphamide (positive control) to induce these structural aberrations. According to the present results, the tested concentrations of the tested pesticides could lead to a collapse of cellular homeostasis and changes in the biochemical and genetic parameters in the Egyptian toads which can be considered as indicators of environmental pollution by pesticides.