Eze Elijah Ajaegbu, Danga Simon Pierre Yinyang, Okoye Festus Basden Chiedu
Department of Biological Sciences, University of Ngaoundere, Ngaoundere, Cameroon, .
J Vector Borne Dis. 2014 Dec;51(4):300-6.
BACKGROUND & OBJECTIVES: Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus are vector mosquitoes of dengue, malaria, and filariasis, respectively. Since no vaccine is available to treat these diseases, the control of the main mosquito vectors is essential. As conventional insecticides have limited success, plants may be alternative larvicidal agents, since they contain a rich source of bioactive chemicals. The aim of this study was to evaluate the larvicidal activity of methanol crude extract, hexane, dichloromethane, acetone, ethyl acetate and methanol fractions of Spondias mombin leaf against IV instar larvae of dengue, malaria, and lymphatic filariasis vector mosquitoes.
A total of 25, IV instar larvae of each target mosquito species were exposed to various concentrations (125-1000 ppm) and were assayed in the laboratory by using the protocol of WHO 2005; the LC50 values were determined by Probit analysis.
Hexane, dichloromethane and acetone fractions were the most effective against Ae. aegypti with LC50 values of 22.54, 42.13, 45.18 ppm, respectively. Hexane fraction registered the highest activity with LC50 of 92.20 ppm against An. gambiae. It was still hexane fraction that showed better toxicity with LC50 of 326.53 ppm against Cx. quinquefasciatus.
The Spondias mombin leaf extracts proved to be a strong candidate for a natural, safe and stable mosquito larvicide to be used in population control of Ae. aegypti, An. gambiae and Cx. quinquefasciatus and so may replace the conventional Diclorvos to control malaria, dengue and filariasis in Nigeria.
埃及伊蚊、冈比亚按蚊和致倦库蚊分别是登革热、疟疾和丝虫病的媒介蚊虫。由于尚无疫苗可用于治疗这些疾病，控制主要蚊虫媒介至关重要。鉴于传统杀虫剂效果有限，植物可能是替代的杀幼虫剂，因为它们含有丰富的生物活性化学物质来源。本研究旨在评估芒果叶甲醇粗提物、己烷、二氯甲烷、丙酮、乙酸乙酯和甲醇部位对登革热、疟疾和淋巴丝虫病媒介蚊虫四龄幼虫的杀幼虫活性。
将每种目标蚊虫的25只四龄幼虫暴露于不同浓度（125 - 1000 ppm）下，并按照世界卫生组织2005年的方案在实验室进行检测；通过概率分析确定半数致死浓度（LC50）值。
己烷、二氯甲烷和丙酮部位对埃及伊蚊最有效，LC50值分别为22.54、42.13、45.18 ppm。己烷部位对冈比亚按蚊活性最高，LC50为92.20 ppm。对致倦库蚊毒性较好的仍是己烷部位，LC50为326.53 ppm。
芒果叶提取物被证明是一种天然、安全且稳定的蚊虫杀幼虫剂的有力候选物，可用于控制埃及伊蚊、冈比亚按蚊和致倦库蚊的种群数量，因此在尼日利亚可能替代传统的敌敌畏来控制疟疾、登革热和丝虫病。
