Instituto Nacional de Pesquisas da Amazônia, Programa de Iniciação Científica, Manaus, AM, Brasil.
Faculdade Uninassau de Manaus, Setor Saúde, Manaus, AM, Brasil.
Rev Soc Bras Med Trop. 2020 Dec 11;53:e20200467. doi: 10.1590/0037-8682-0467-2020. eCollection 2020.
Semi-synthetic dillapiole compounds derived from Piper aduncum essential oil are used as alternative insecticides to control insecticide-resistant Aedes aegypti. Thus, we aimed to evaluate the genotoxic effects of semi-synthetic isodillapiole on the nuclei of neuroblasts (larvae) and oocytes (females) and the mean oviposition rates of the females over four generations (G1, G2, G3, and G4) of Ae. aegypti.
Larvae were captured in the city of Manaus, Amazonas state, Brazil, and exposed to isodillapiole in bioassays (20, 40, and 60 µg/mL) and a negative control (0.05% DMSO in tap water) for 4 h. The cerebral ganglia were extracted from the larvae and oocytes from the adult females to prepare slides for cytogenetic analysis. Breeding pairs were established and eggs counts were quantified taken after the bioassays.
The analysis of 20,000 interphase nuclei of neuroblasts and oocytes indicated significant genotoxicity (micronuclei, budding, polynucleated cells, and other malformations) compared to that of the control. Metaphasic and anaphasic nuclei presented chromosomal breaks; however, no significant variation and damage was observed in the negative control. A significant reduction in mean oviposition rates was also recorded following exposure to isodillapiole over the four generations (G1, G2, G3, and G4).
The toxic and genotoxic effects of isodillapiole on Ae. aegypti were caused by reduced oviposition in the females and nuclear abnormalities over the four generations of the trials. Further studies are required, rather than our in vitro assays, to verify the efficacy of exposure to this compound for controlling Ae. aegypti.
从蓬蒿 Piper aduncum 精油中衍生出的半合成土木香内酯化合物被用作替代杀虫剂来控制抗杀虫剂的埃及伊蚊。因此，我们旨在评估半合成异土木香内酯对神经母细胞（幼虫）和卵母细胞（雌性）细胞核的遗传毒性作用，以及该化合物对埃及伊蚊雌性在四代（G1、G2、G3 和 G4）中的平均产卵率的影响。
幼虫在巴西亚马逊州玛瑙斯市捕获，并在生物测定中暴露于异土木香内酯（20、40 和 60μg/mL）和阴性对照（0.05% DMSO 在自来水中）4 小时。从幼虫的大脑神经节和成年雌性的卵母细胞中提取，制备用于细胞遗传学分析的载玻片。建立繁殖对，并在生物测定后定量计数卵数。
与对照组相比，20000 个神经母细胞和卵母细胞的间期核分析显示出显著的遗传毒性（微核、芽生、多核细胞和其他畸形）。有丝分裂和减数分裂核呈现染色体断裂；然而，在阴性对照中没有观察到明显的变化和损伤。暴露于异土木香内酯后，四个世代（G1、G2、G3 和 G4）的平均产卵率也显著降低。
异土木香内酯对埃及伊蚊的毒性和遗传毒性作用是由于雌性产卵减少和试验四代的核异常所致。需要进一步的研究，而不是我们的体外试验，以验证暴露于该化合物控制埃及伊蚊的效果。
