Edwin Edward-Sam, Vasantha-Srinivasan Prabhakaran, Senthil-Nathan Sengottayan, Thanigaivel Annamalai, Ponsankar Athirstam, Pradeepa Venkatraman, Selin-Rani Selvaraj, Kalaivani Kandaswamy, Hunter Wayne B, Abdel-Megeed Ahmed, Duraipandiyan Veeramuthu, Al-Dhabi Naif Abdullah
Division of Biopesticides and Environmental Toxicology, Sri Paramakalyani Centre for Excellence in Environmental Sciences, Manonmaniam Sundaranar University Alwarkurichi, Tirunelveli, Tamil Nadu 627 412, India.
Division of Biopesticides and Environmental Toxicology, Sri Paramakalyani Centre for Excellence in Environmental Sciences, Manonmaniam Sundaranar University Alwarkurichi, Tirunelveli, Tamil Nadu 627 412, India.
Acta Trop. 2016 Nov;163:167-78. doi: 10.1016/j.actatropica.2016.07.009. Epub 2016 Jul 18.
The current study investigated the toxic effect of the leaf extract compound andrographolide from Andrographis paniculata (Burm.f) against the dengue vector Ae. aegypti. GC-MS analysis revealed that andrographolide was recognized as the major chemical constituent with the prominent peak area compared with other compounds. All isolated toxic compounds were purified and confirmed through RP-HPLC against chemical standards. The larvicidal assays established at 25ppm of bioactive compound against the treated instars of Ae. Aegypti showed prominent mortality compared to other treated concentrations. The percent mortality of larvae was directly proportional to concentration. The lethal concentration (LC50) was observed at 12ppm treatment concentration. The bioactive andrographolide considerably reduced the detoxifying enzyme regulations of α- and β- carboxylesterases. In contrast, the levels of GST and CYP450 significantly increase in a dose dependent manner. The andrographolide also showed strong oviposition deterrence effects at the sub-lethal dose of 12ppm. Similarly, the mean number of eggs were also significantly reduced in a dose dependent manner. At the concentration of 12ppm the effective percentage of repellency was greater than 90% with a protection time of 15-210min, compared with control. The histopathology study displayed that larvae treated with bioactive andrographolide had cytopathic effects in the midgut epithelium compared with the control. The present study established that bioactive andrographolide served as a potential useful for dengue vector management.
本研究调查了穿心莲叶提取物穿心莲内酯对登革热媒介埃及伊蚊的毒性作用。气相色谱-质谱联用（GC-MS）分析表明，与其他化合物相比，穿心莲内酯是主要化学成分，具有突出的峰面积。所有分离出的有毒化合物均通过反相高效液相色谱（RP-HPLC）与化学标准品进行纯化和确认。以25ppm的生物活性化合物对埃及伊蚊各龄期幼虫进行的杀幼虫试验显示，与其他处理浓度相比，死亡率显著。幼虫的死亡率百分比与浓度成正比。在12ppm的处理浓度下观察到致死浓度（LC50）。生物活性穿心莲内酯显著降低了α-和β-羧酸酯酶的解毒酶活性。相反，谷胱甘肽S-转移酶（GST）和细胞色素P450（CYP450）的水平以剂量依赖方式显著增加。穿心莲内酯在12ppm的亚致死剂量下也表现出强烈的产卵抑制作用。同样，平均产卵数也以剂量依赖方式显著减少。在12ppm的浓度下，与对照相比，有效驱避率大于90%，保护时间为15 - 210分钟。组织病理学研究显示，与对照相比，用生物活性穿心莲内酯处理的幼虫中肠上皮细胞出现细胞病变效应。本研究证实，生物活性穿心莲内酯对登革热媒介的管理具有潜在的实用价值。
