Pak J Biol Sci. 2022 Jan;25(3):263-269. doi: 10.3923/pjbs.2022.263.269.
<b>Background and Objective:</b> The methanol, ethyl acetate and n-hexane extracts of <i>D. elliptica</i> root have high larvicidal activity against <i>Aedes aegypti</i> larvae, the primary vector of dengue but have not been understood their potential against <i>Ae. albopictus</i> larvae, the secondary vector of dengue that also transmits Chikungunya and Zika viruses. This <i>in vitro</i> study aims to understand the larvicidal activity of the 3 extract types of <i>D. elliptica </i>root against <i>Ae. albopictus</i> larvae. <b>Materials and Methods:</b> The tuba root extract types were obtained from the sequential extraction process with 3 steps of liquid-liquid partition as described in the previous report. Six concentrations were occupied in this experiment ranging of 0.5, 1.0, 2.0, 4.0, 10.0 and 15.0 mg L<sup>1</sup> each concentration was 5 times replicated and placed in 250 mL plastic cups. As many as 20 of 3rd instar larvae of <i>Ae. albopictus</i> were subjected in each treatment cup and larval mortality was observed after 24 and 48 hrs of exposure. <b>Results:</b> Larval mortality rates based on concentration range of 13.75-97.00 and 43,75-100%, 14.00-44.00, 34.00-90.00%, 12.00-47.00 and 28.00-88.00%, with the LC<sub>50</sub> after 24 and 48 hrs of exposure were 2.925 and 0.414, 16.184, 2.900, 15.789 and 4.380 mg L<sup>1</sup>, respectively for methanol, ethyl acetate and n-hexane extracts. <b>Conclusion:</b> The methanol, ethyl acetate and n-hexane extract of tuba root have high larvicidal activity against <i>Ae. albopictus</i> larvae. Further study on prototype formulation of larvicide and elucidation of the specific phytochemical compounds of the extracts were necessarily conducted.
背景与目的：桐花树根的甲醇、乙酸乙酯和正己烷提取物对埃及伊蚊幼虫具有高杀幼虫活性，埃及伊蚊是登革热的主要传播媒介，但对登革热的次要传播媒介白纹伊蚊幼虫的潜在作用尚未了解，白纹伊蚊还传播基孔肯雅热和寨卡病毒。本体外研究旨在了解桐花树根 3 种提取物类型对白纹伊蚊幼虫的杀幼虫活性。材料与方法：管状根提取物类型是通过与先前报道中描述的 3 步液-液分配过程的连续提取过程获得的。本实验共设 6 个浓度，范围为 0.5、1.0、2.0、4.0、10.0 和 15.0mg L1，每个浓度重复 5 次，置于 250ml 塑料杯中。每个处理杯中放入 20 只 3 龄白纹伊蚊幼虫，暴露 24 和 48 小时后观察幼虫死亡率。结果：基于浓度范围 13.75-97.00 和 43.75-100%、14.00-44.00、34.00-90.00%、12.00-47.00 和 28.00-88.00%的幼虫死亡率分别为 13.75-97.00%和 43.75-100%、14.00-44.00%、34.00-90.00%、12.00-47.00%和 28.00-88.00%，LC50值分别为 24 和 48 小时后的 2.925 和 0.414、16.184、2.900、15.789 和 4.380mg L1，甲醇、乙酸乙酯和正己烷提取物。结论：桐花树根的甲醇、乙酸乙酯和正己烷提取物对白纹伊蚊幼虫具有高杀幼虫活性。有必要进一步研究原型杀幼虫剂配方和阐明提取物的特定植物化学化合物。
