The risks of the health-associated problems of pesticide-exposed non-target organisms are ubiquitous, therefore an emerging concern to strike the balance between benefit and risk factors. In the present study, by elucidating multiple biomarkers, the effects of Phenthoate 50 EC on the acute toxicity tests and different pathophysiological changes of common carp (Cyprinus carpio) fingerlings were studied in time- and concentration-dependent manners. The LC50 of Phenthoate 50 EC for the fish was 7.39 (6.716-8.076) ppm at 96 h. As an indicator of neurotoxicity, compared to the control group, significant (P < 0.01) reduction in brain acetylcholinesterase (AChE) activity was observed, whereas plasma glutamate-oxalacetate transaminase (PGOT) and plasma glutamate pyruvate transaminase (PGPT) activities were increased significantly (P < 0.01) at the doses of 2.22 and 3.69 ppm of Phenthoate 50 EC, respectively. Histopathological changes in the insecticide-treated fish liver suggested the hepatic tissue damages, while alteration of the blood, gills and kidney morphology; progressive decrease (P < 0.05) in the serum calcium levels; and significantly (P < 0.01) decreased blood glucose level at 2.22 and 3.69 or 5.17 ppm of Phenthoate 50 EC demonstrated the oxidative stress and requirement of the up-surging energy demands due to the exposure of this organophosphate chemical. These results advice the modulation caused by this widely used agrochemical on the physiology of aquatic fauna by changing the enzymatic and biochemical indices at cellular level.
Keywords: Acetylcholinesterase activity; Calcium; Glucose; Glutamate pyruvate transaminase activity; Glutamate-oxalacetate transaminase activity; Phenthoate 50 EC.