Nanomedicine and Nanotoxicology Group, São Carlos Institute of Physics, University of São Paulo, Sao Carlos, São Paulo, 13560-970, Brazil.
Optical Group, São Carlos Institute of Physics, University of São Paulo, Sao Carlos, São Paulo, 13560-970, Brazil.
Environ Sci Pollut Res Int. 2020 Aug;27(23):29204-29217. doi: 10.1007/s11356-020-09210-4. Epub 2020 May 20.
Aedes aegypti is the vector of important diseases like dengue, zika, chikungunya, and yellow fever. Vector control is pivotal in combating the spread of these mosquito-borne illnesses. Photoactivable larvicide curcumin obtained from Curcuma longa Linnaeus has shown high potential for Ae. aegypti larvae control. However, the toxicity of this photosensitizer (PS) might jeopardize non-target aquatic organisms. The aim of this study was to evaluate the toxicity of this PS to Daphnia magna and Danio rerio, besides assessing its mode of action through larvae biochemical and histological studies. Three PS formulations were tested: PS in ethanol+DMSO, PS in sucrose, and PS in D-mannitol. The LC of PS in ethanol+DMSO to D. rerio was 5.9 mg L, while in D. magna the solvents were extremely toxic, and LC was not estimated. The PS formulations in sugars were not toxic to neither of the organisms. Reactive oxygen species (ROS) were generated in D. magna exposed to 50 mg L of PS in D-mannitol, and D. rerio did not elicit this kind of response. D. magna feeding rates were not affected by the PS in D-mannitol. Concerning Ae. aegypti larvae, there were changes in reduced glutathione and protein levels, while catalase activity remained stable after exposure to PS in D-mannitol and sunlight. Histological changes were observed in larvae exposed to PS in sucrose and D-mannitol, most of them irreversible and deleterious. Our results show the feasibility of this photolarvicide use in Ae. aegypti larvae control and its safety to non-target organisms. These data are crucial to this original vector control approach implementation in public health policies.
埃及伊蚊是登革热、寨卡、基孔肯雅热和黄热病等重要疾病的传播媒介。病媒控制对于控制这些蚊媒疾病的传播至关重要。从姜黄属植物姜黄中获得的光活化幼虫杀生物剂姜黄素已显示出对埃及伊蚊幼虫控制的巨大潜力。然而，这种光敏剂 (PS) 的毒性可能危及非目标水生生物。本研究旨在评估这种 PS 对大型溞和斑马鱼的毒性，并通过幼虫生化和组织学研究评估其作用方式。测试了三种 PS 制剂：乙醇+DMSO 中的 PS、蔗糖中的 PS 和 D-甘露醇中的 PS。乙醇+DMSO 中 PS 对斑马鱼的 LC 为 5.9mg/L，而在大型溞中，溶剂极毒，无法估计 LC。糖中的 PS 制剂对两种生物均无毒性。暴露于 50mg/L D-甘露醇中的 PS 会在大型溞中产生活性氧 (ROS)，而斑马鱼则不会产生这种反应。PS 在 D-甘露醇中对大型溞的摄食率没有影响。关于埃及伊蚊幼虫，还原型谷胱甘肽和蛋白质水平发生变化，而过氧化氢酶活性在暴露于 D-甘露醇和阳光中的 PS 后保持稳定。暴露于蔗糖和 D-甘露醇中的 PS 的幼虫观察到组织学变化，其中大多数是不可逆和有害的。我们的结果表明，这种光幼虫杀生物剂在埃及伊蚊幼虫控制中的使用具有可行性，对非目标生物是安全的。这些数据对于在公共卫生政策中实施这种原始的病媒控制方法至关重要。
