Abstract

Parastar is an insecticide formulation of lambda-cyhalothrin and imidacloprid largely used for crop protection in North West Region of Cameroon. In the present study, we evaluated the behavioral activities and motor function of Wistar male rats after subchronic treatment with the pesticide formulation. To this end, three groups of adult rats were administered Parastar at doses 1.25, 2.49 and 6.23 mg/kg, respectively, for 35 days. A control group was included and received distilled water. At the end of the treatment, the animals were submitted to behavioral and functional tests (open field test, elevated plus maze test, light-dark box test, forced swimming test, tail suspension test, beam-walking test, grid suspension test and wire hang test) for estimation of anxiety, exploration, depression and motor coordination. Results revealed that Parastar, at the higher doses tested, 2.49 and 6.23 mg/kg, induced anxiogenic-like pattern behavior in rats in all behavioral assays including open field test (total distance moved, total lines crossed, frequency and total time in center square were all reduced), elevated plus maze (decreased total time spent in open arms and the number of entries in open arms of the elevated plus maze), and light-dark box (the dark box duration increased, while light box duration time and frequency of transition between dark and light box decreased). Treatment with 2.49 and 6.23 mg/kg Parastar increased the immobility time of animals in both forced swimming test and tail suspension test. The insecticide induced decrease in the distance traveled, foot slip and number of turns of animals in the beam walking test. Parastar also decreased the animal suspension time in both grid suspension grip-strength test and the wire hang test. Taken altogether, these results suggest that subchronic administration of Parastar at the doses of 2.49 and 6.23 mg/kg induced anxiety-like and depressive-like behavior as well as impaired motor coordination and muscle strength in male rats.

摘要

Parastar 是一种高效氯氟氰菊酯和吡虫啉的杀虫剂配方，主要用于喀麦隆西北地区的作物保护。在本研究中，我们评估了 Wistar 雄性大鼠在亚慢性农药制剂治疗后的行为活动和运动功能。为此，三组成年大鼠分别以 1.25、2.49 和 6.23 mg/kg 的剂量服用 Parastar，持续 35 天。包括对照组并接受蒸馏水。在治疗结束时，对动物进行行为和功能测试（旷场测试、高架加迷宫测试、明暗箱测试、强迫游泳测试、尾巴悬吊测试、光束行走测试、网格悬吊测试和电线悬挂测试）用于评估焦虑、探索、抑郁和运动协调。结果显示，Parastar，在较高的测试剂量下，2.49 和 6.23 mg/kg，在包括旷场测试在内的所有行为测定中诱导大鼠的焦虑样模式行为（移动的总距离、交叉的总线、中心正方形的频率和总时间都减少了），高架十字迷宫（减少了在张开双臂中花费的总时间和进入高架十字迷宫的张开双臂的次数）和明暗箱（暗箱持续时间增加，而灯箱持续时间和黑暗和之间的过渡频率）灯箱减少）。用 2.49 和 6.23 mg/kg Parastar 处理增加了动物在强迫游泳试验和悬尾试验中的不动时间。杀虫剂导致横梁行走试验中动物行走距离、脚滑和转弯次数减少。Parastar 还减少了在网格悬挂握力测试和钢丝悬挂测试中的动物悬挂时间。总而言之，这些结果表明，以 2.49 和 6.23 mg/kg 的剂量亚慢性给药 Parastar 会导致雄性大鼠出现焦虑样和抑郁样行为以及运动协调和肌肉力量受损。