Medical Malacology Department, Theodor Bilharz Research Institute, Giza, Egypt.
Pestic Biochem Physiol. 2022 Aug;186:105154. doi: 10.1016/j.pestbp.2022.105154. Epub 2022 Jun 26.
Organophosphorus pesticides like Chlorpyrifos 48%EC were widely used to control agricultural pests. The present study aimed to evaluate the toxic effects of Chlorpyrifos 48%EC on B. alexandrina snails, the intermediate host of Schistosoma mansoni. After exposure of snails to serial concentrations to determine the LC, thirty snails for each sublethal concentration (LC 2.1 and LC 5.6 mg/l) in each group were exposed for 24 h followed by another 24 h for recovery. After recovery random samples were collected from hemolymph and tissue to measure the impacts on Phagocytic index, histological, biochemical, and molecular parameters. The current results showed a toxic effect of Chlorpyrifos 48%EC on adult B. alexandrina snails after 24 h of exposure at LC 9.6 mg/l. After exposure to the sub-lethal concentrations of this pesticide, it decreased the total number of hemocytes and the percentage of small cells, while increased the percentage of hyalinocytes. The granulocyte percentage was increased after exposure to LC, while after LC, it was decreased compared to the control group. Also, the light microscopical examination showed that some granulocytes have plenty of granules, vacuoles and filopodia. Some hyalinocytes were contained shrinked nuclei, incomplete cell division and forming pseudopodia. Besides, the phagocytic index of hemocytes was significantly increased than control in all treated groups. Also, these sub-lethal concentrations increased MDA and SOD activities, while, tissue NO, GST and TAC contents were significantly decreased after exposure. Levels of Testosterone (T) and Estradiol (E) were increased significantly after exposure compared with control group. The present results showed that the concentration of DNA and RNA was highly decreased after exposure to LC, than the control group. Therefore, B. alexandrina snails could be used as a bio monitor of the chemical pollution. Besides, this pesticide could reduce the transmission of schistosomiasis as it altered the biological system of these snails.
有机磷农药如毒死蜱 48%EC 被广泛用于防治农业害虫。本研究旨在评估毒死蜱 48%EC 对中间宿主曼氏血吸虫的亚历山大萝卜螺的毒性作用。在暴露于一系列浓度以确定 LC 后，每组 30 只螺（LC 2.1 和 LC 5.6mg/l）暴露于亚致死浓度 24 小时，然后再恢复 24 小时。恢复后，从血淋巴和组织中随机采集样本，以测量对吞噬指数、组织学、生化和分子参数的影响。目前的结果表明，在 LC 9.6mg/l 暴露 24 小时后，毒死蜱 48%EC 对成年亚历山大萝卜螺具有毒性作用。暴露于该农药的亚致死浓度后，它降低了总血细胞数和小细胞的百分比，而增加了透明细胞的百分比。粒细胞百分比在暴露于 LC 后增加，而暴露于 LC 后与对照组相比降低。此外，光镜检查显示，一些粒细胞含有大量颗粒、空泡和丝状伪足。一些透明细胞含有收缩的核、不完全的细胞分裂和伪足的形成。此外，与对照组相比，所有处理组的血细胞吞噬指数均显著增加。此外，这些亚致死浓度增加了 MDA 和 SOD 的活性，而组织中 NO、GST 和 TAC 的含量在暴露后显著降低。与对照组相比，暴露后睾酮（T）和雌二醇（E）的水平显著增加。与对照组相比，暴露于 LC 后 DNA 和 RNA 的浓度显著降低。因此，亚历山大萝卜螺可作为化学污染的生物监测器。此外，这种农药可以减少血吸虫病的传播，因为它改变了这些蜗牛的生物系统。
