The Neurotoxicity of Acetamiprid and Pendimethalin is Enhanced by Their Combined Exposure in Oreochromis Niloticus

The investigation of pesticide combination toxicity has received more attention than the assessment of individual pesticides over the last decade, due to their overuse in agricultural and veterinary practices. The aim of our study is to evaluate the neurotoxic effects of acetamiprid and pendimethalin after single and combined exposure in Oreochromis niloticus. In this experiment, 120 healthy Nile tilapia juveniles (15 ± 3 g) were used. Fish were randomly distributed into four groups (30 fish each), as follows: a control group, an acetamiprid-intoxicated group, a pendimethalin-intoxicated group, and a group that received both acetamiprid and pendimethalin for 28 successive days. Biomarkers of oxidative stress, including malondialdehyde (MDA), protein carbonyl, and 8-hydroxy-2\'-deoxyguanosine (8-OHdG) levels, along with acetylcholinesterase (AChE) activity, were evaluated spectrophotometrically in the brain. In addition, histopathological alterations in the brain were assessed. The results revealed a significant elevation in oxidative stress markers across all exposed groups, with the highest levels detected in the co-exposed group. Moreover, the most severe brain tissue lesions were observed in this group. These findings indicate that co-exposure to acetamiprid and pendimethalin intensifies their neurotoxic effects in Nile tilapia.