Single and joint toxicity of ethoprophos and bispyribac-sodium to Oreochromis niloticus: biochemical and genotoxic responses

Pesticides can bioaccumulate in fish tissues, and there are serious concerns around the world about their effects on consumer health. The objective of this study was to highlight the effects of two commercial pesticides, ethoprophos and bispyribac-sodium, commonly used on high-consumption crops in Egypt, either individually or in mixture, on some biomarkers of Nile tilapia, Oreochromis niloticus, an important commercial fish species. Low concentrations of ethoprophos (96 µg/L) and bispyribac-sodium (1.28 µg/L) were selected to evaluate the effect of these substances on neurotoxic marker (acetylcholine esterase, AChE), liver function parameters (alkaline phosphatase, ALP; alanine aminotransferase, ALT; and aspartate aminotransferase, AST), and renal function parameters (creatinine and urea), as well as genotoxic marker (micronuclei, MN; and other nuclear abnormalities) during variable periods (7, 14, 21, and 28 days). The results demonstrate that ethoprophos and bispyribac-sodium pose a risk to native freshwater fish by causing detrimental effects. Both compounds, separately and in combination, induced neurotoxicity, hepatorenal biomarkers inductions, and increases in MN frequency and other erythrocytic nuclear abnormalities in a time-dependent manner. Moreover, the mixture displayed both synergistic and antagonistic interactions for examined parameters. This study highlights the importance of using validated biomarkers to monitor fish health, which may be utilized as early alarms of environmental risks.