Zoology Government Degree College Kukatpally, Hyderabad, Telangana, India.
Applied Statistics Department of Applied Statistics, Telangana University, Nizamabad, Telangana, India.
Comp Biochem Physiol C Toxicol Pharmacol. 2023 Sep;271:109689. doi: 10.1016/j.cbpc.2023.109689. Epub 2023 Jun 24.
Neonicotinoid insecticide residues are found frequently in different water resources, but the knowledge of their ecological consequences is scanty. The present research focused on one-third of the LC concentration of the two neonicotinoids imidacloprid (66.6 mg/L) and clothianidin (30 mg/L) individually and a mixture (range of 33.3 + 15 mg/L) were exposed to Labeo rohita for 42 days. The investigation evaluated the single and combined insecticidal antagonistic effects on fish cholinesterases (AChE and BChE), oxidative stress activities, and DNA damage (8-OHdG) after intoxication. The imidacloprid (IMI), clothianidin (CLO), and combination intoxication significantly reduced AChE and BChE enzyme activities in the brain, muscle, and serum. The highest levels of AChE inhibition were found in the muscle and brain, whereas the highest levels of BChE were seen in the serum and muscle in the mixed group. The enzymatic and non-enzymatic oxidative activities in the brain and liver varied, with significant increases in superoxide dismutase, catalase activities, lipid peroxidation levels, glutathione S-transferase activity, and a decreasing trend in reduced glutathione levels compared to controls. The 8-OHdG activity increased significantly in proportion to exposure time, while the liver showed the highest increase, followed by the brain in the mixture group. Long-period exposure to neonicotinoids can cause severe neurotoxicity by inhibiting cholinesterase, altering antioxidant activities, and inducing DNA damage (increasing 8-OHdG). The results showed that clothianidin is more toxic than imidacloprid as a single active ingredient, whereas the mixture of two insecticides is more toxic than the single active ingredients.
新烟碱类杀虫剂残留频繁出现在不同的水资源中，但对其生态后果的了解甚少。本研究重点关注两种新烟碱类杀虫剂吡虫啉（66.6mg/L）和噻虫嗪（30mg/L）的三分之一 LC 浓度，以及单独暴露和混合物（范围为 33.3+15mg/L）对罗非鱼（Labeo rohita）的 42 天影响。该研究评估了单一和联合杀虫剂对鱼类胆碱酯酶（AChE 和 BChE）、氧化应激活性和 DNA 损伤（8-OHdG）的拮抗作用。吡虫啉（IMI）、噻虫嗪（CLO）和联合中毒显著降低了鱼脑、肌肉和血清中的 AChE 和 BChE 酶活性。AChE 抑制的最高水平出现在肌肉和大脑中，而 BChE 的最高水平出现在混合组的血清和肌肉中。大脑和肝脏的酶促和非酶促氧化活性发生变化，超氧化物歧化酶、过氧化氢酶活性、脂质过氧化水平、谷胱甘肽 S-转移酶活性显著增加，与对照组相比，还原型谷胱甘肽水平呈下降趋势。8-OHdG 活性随着暴露时间的增加而显著增加，而肝脏的增加幅度最大，其次是混合组的大脑。新烟碱类农药长期暴露会通过抑制胆碱酯酶、改变抗氧化活性和诱导 DNA 损伤（增加 8-OHdG）而导致严重的神经毒性。结果表明，噻虫嗪作为单一活性成分比吡虫啉毒性更大，而两种杀虫剂的混合物比单一活性成分毒性更大。
