Serra Raissa Santana, Martínez Luis Carlos, Cossolin Jamile Fernanda Silva, Resende Matheus Tudor Candido Santos de, Carneiro Lenise Silva, Fiaz Muhammad, Serrão Jose Eduardo
Department of General Biology, BIOAGRO, Federal University of Viçosa, Viçosa, MG, Brazil.
Ecotoxicology. 2023 Mar;32(2):234-242. doi: 10.1007/s10646-023-02633-y. Epub 2023 Feb 6.
Apis mellifera is an important bee pollinating native and crop plants but its recent population decline has been linked to the use of pesticides, including fungicides that have been commonly classified as safe for bees. However, many pesticides, in addition to direct mortality cause sublethal effects, including damage to target selective honey bee organs. The midgut is the organ responsible for the digestion and absorption of nutrients and the detoxification of ingested substances, such as pesticides. This study evaluated the histopathological and cytotoxic changes in the midgut of A. mellifera workers caused by the pesticide azoxystrobin. The limit-test was performed, and a 100 µg a.i./bee dose was administered orally and midgut analyzed with light and transmission electron microscopies after 24 h and 48 h of pesticide exposure. The midgut of the control bees has a single layer of digestive cells, with spherical nuclei, nests of regenerative cells, and the lumen coated with the peritrophic matrix. The bees fed on azoxystrobin showed morphological changes, including intense cytoplasm vacuolization and cell fragments released into the gut lumen. The protein detection test showed greater staining intensity in the nests of regenerative cells after 24 h of exposure to azoxystrobin. The occurrence of damage to the midgut in A. mellifera exposed to azoxystrobin indicates that although this fungicide has been classified as low toxicity for bees, it has sublethal effects in the midgut, and effects in other organs should be investigated.
意大利蜜蜂是一种重要的蜜蜂，为本地植物和农作物授粉，但其最近的种群数量下降与农药的使用有关，包括通常被归类为对蜜蜂安全的杀菌剂。然而，许多农药除了直接致死外还会造成亚致死效应，包括对目标选择性蜜蜂器官的损害。中肠是负责营养物质消化和吸收以及摄入物质（如农药）解毒的器官。本研究评估了农药嘧菌酯对意大利蜜蜂工蜂中肠的组织病理学和细胞毒性变化。进行了极限试验，以100μg有效成分/只蜜蜂的剂量口服给药，在农药暴露24小时和48小时后，用光镜和透射电子显微镜分析中肠。对照蜜蜂的中肠有单层消化细胞，细胞核呈球形，有再生细胞巢，肠腔被围食膜覆盖。喂食嘧菌酯的蜜蜂出现形态变化，包括强烈的细胞质空泡化和释放到肠腔中的细胞碎片。蛋白质检测试验显示，在暴露于嘧菌酯24小时后，再生细胞巢中的染色强度更大。暴露于嘧菌酯的意大利蜜蜂中肠出现损伤表明，尽管这种杀菌剂被归类为对蜜蜂低毒，但它在中肠有亚致死效应，其他器官的效应也应进行研究。
