Behavioral Changes in Male Gerbils Following Subacute Exposure to K-Optimal 35 EC Pesticide Formulation

Background and Objective: Despite their benefits in agriculture, pesticides can be hazardous to non-target organisms, including animals and humans. The present study assessed the subacute toxicity of K-Optimal, an agro-pesticide formulation containing lambda-cyhalothrin and acetamiprid. Materials and Methods: Three groups of male gerbils were given either the vehicle or K-Optimal at doses 8.75 and 17.5 mg kg‾¹, 6 days a week for 4 weeks. The animal’s body weight was recorded every 4 days and behavioral tests were carried out from day 20-25 of the experiment to assess anxiety, exploration and motor coordination. The gerbils were sacrificed on day 29 and serum was used for assessment of cholinesterase and aminotransferase activities, uric acid, total antioxidant capacity (TAC) and testosterone levels. Brain nitric oxide (NO) levels were also determined while catalase activity, glutathione and thiobarbituric reactive substances levels were assessed in the liver, testis and brain. Results: Exposure to K-Optimal resulted in anxiety-like behavior characterized by decreased suspension time in the hanging wire test and decreased grooming frequency and time spent at the center in the open field test. The K-Optimal induced increased liver weight while decreasing body weight. There were decreased brain NO levels as well as increased TAC, though the latter occurred only in the animals exposed to 8.75 mg kg‾¹ pesticide. Conclusion: Subacute exposure to K-optimal induced anxiety-like behavior and impaired motor coordination in the gerbils, which may result from decreased brain NO levels. The pesticide also alters body and liver weights and should therefore be considered a potential health hazard for humans and other animals.