Leandro C S, Azevedo F R, Cândido E L, Alencar C H
Universidade Federal do Cariri, Centro de Ciências Agrárias e da Biodiversidade, Crato, CE, Brasil.
Universidade Federal do Ceará, Faculdade de Medicina, Programa de Pós-Graduação em Saúde Pública, Fortaleza, CE, Brasil.
Braz J Biol. 2023 Apr 17;83:e270143. doi: 10.1590/1519-6984.270143. eCollection 2023.
The aim of this study was to carry out phytochemical prospecting and evaluate the larvicidal activity of Himatanthus drasticus latex extracts against Aedes aegypti. The extracts were obtained by maceration from 5 g of latex powder concentrated separately in 100 mL of methanol, ethyl acetate, and hexane solvents. The concentrations of 100, 200, 300, 400, and 500 ppm of each extract were tested in triplicate with a solution of pyriproxyfen as the positive control and distilled water and dimethylsulfoxide as the negative control. The phytochemical prospection of the methanolic extract showed the presence of phenolic compounds, such as anthocyanins, anthocyanidins, catechins, chalcones, aurones, leucoanthocyanidins, and condensed tannins. The insecticidal bioactivity was most significant for the methanolic extract. The methanolic extract lethal concentrations (LC) of 50 and 90% were 190.76 and 464.74 ppm, respectively. After 48 hours of exposure, the extracts using methanol, ethyl acetate, and hexane at their highest concentrations (500 ppm) caused larval mortality of 100, 73.33, and 66.67%, respectively. These extracts also promoted changes in the external morphology of the larvae, such as damage to the anal papillae, darkening of the body, and reduction in the number of bristles. The methanolic extract showed greater expressivity for morphological changes. The latex of H. drasticus has larvicidal activity against third-stade larvae of A. aegypti and it is more significant when obtained through maceration in methanol. The methanolic extract of H. drasticus latex contains phenolic compounds with insecticidal activity against A. aegypti larvae.
本研究的目的是进行植物化学勘探，并评估伞树属植物（Himatanthus drasticus）乳胶提取物对埃及伊蚊的杀幼虫活性。通过浸渍法从分别浓缩在100 mL甲醇、乙酸乙酯和己烷溶剂中的5 g乳胶粉中获得提取物。每种提取物的100、200、300、400和500 ppm浓度进行了三次重复测试，以吡丙醚溶液作为阳性对照，蒸馏水和二甲基亚砜作为阴性对照。甲醇提取物的植物化学勘探显示存在酚类化合物，如花色苷、花青素、儿茶素、查耳酮、噢哢、无色花青素和缩合单宁。甲醇提取物的杀虫生物活性最为显著。甲醇提取物的50%和90%致死浓度（LC）分别为190.76和464.74 ppm。暴露48小时后，使用甲醇、乙酸乙酯和己烷的提取物在其最高浓度（500 ppm）下分别导致幼虫死亡率为100%、73.33%和66.67%。这些提取物还促使幼虫的外部形态发生变化，如肛门乳突受损、身体变黑和刚毛数量减少。甲醇提取物在形态变化方面表现出更大的显著性。伞树属植物的乳胶对埃及伊蚊的三龄幼虫具有杀幼虫活性，当通过在甲醇中浸渍获得时活性更为显著。伞树属植物乳胶的甲醇提取物含有对埃及伊蚊幼虫具有杀虫活性的酚类化合物。
