Departamento de Bioquímica, Centro de Biociências, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
Departamento de Química Fundamental, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
Acta Trop. 2021 Feb;214:105789. doi: 10.1016/j.actatropica.2020.105789. Epub 2020 Dec 9.
The measures currently used to minimize the spread of arboviruses, comprising dengue, Chikungunya, and Zika virus, involve controlling the size of population of the mosquito Aedes aegypti. However, the search for formulations containing new insecticides is gaining pace due to reports of mosquito populations showing resistance to commonly used compounds. In this study, tablets containing a protein fraction of Moringa oleifera seeds enriched in the WSMoL lectin, known to show larvicidal and ovicidal activities against A. aegypti, were developed. The compatibility between the fraction and the excipients used in obtaining the tablets was evaluated by thermogravimetry (TG), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) absorption spectroscopy. The larvicidal and ovicidal activities of the resulting tablets [5%, 10%, and 15% (w/w) of the fraction] were evaluated, as well as their effect on mosquito oviposition. Assays were also performed using a placebo tablet. According to the TG, DSC, and FTIR results, the protein composition of the fraction did not change when mixed with the components of the formulation. Tablets containing 10% and 15% WSMoL-rich fraction caused mortality of 42.5% and 95% of the larvae after 48 h, respectively, with larvae incubated with these tablets showing reduced acetylcholinesterase activity. All tablets inhibited egg hatching after 72 h (36-74%), and tablets containing 15% fraction were found to exert a repellent effect on oviposition. Our results show that the formulation developed in this study interfered with the life cycle of A. aegypti, and thus show potential for use in the control of this mosquito.
目前用于最小化虫媒病毒（包括登革热、基孔肯雅热和寨卡病毒）传播的措施包括控制埃及伊蚊的种群数量。然而，由于报道称蚊子种群对常用化合物产生了抗药性，因此寻找含有新杀虫剂的配方的步伐正在加快。在这项研究中，开发了含有富含 WSMoL 凝集素的辣木种子蛋白部分的片剂，已知该凝集素对埃及伊蚊具有杀幼虫和杀卵活性。通过热重分析（TG）、差示扫描量热法（DSC）和傅里叶变换红外（FTIR）吸收光谱法评估了该部分与获得片剂所用赋形剂的相容性。评估了所得片剂（部分的 5%、10%和 15%（w/w））的杀幼虫和杀卵活性，以及它们对蚊子产卵的影响。还使用安慰剂片剂进行了测定。根据 TG、DSC 和 FTIR 结果，当与制剂成分混合时，部分的蛋白质组成没有变化。含有 10%和 15% WSMoL 丰富部分的片剂在 48 小时后分别导致 42.5%和 95%的幼虫死亡，用这些片剂孵育的幼虫乙酰胆碱酯酶活性降低。所有片剂在 72 小时后均抑制卵孵化（36-74%），并且发现含有 15%部分的片剂对产卵具有驱避作用。我们的结果表明，本研究中开发的配方干扰了埃及伊蚊的生命周期，因此具有控制这种蚊子的潜力。
