Mukandiwa Lillian, Eloff Jacobus Nicolaas, Naidoo Vinny
Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, P. Bag X04 Onderstepoort, Pretoria, 0110, South Africa.
Biomedical Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria, 0110, South Africa.
Environ Sci Pollut Res Int. 2016 Jun;23(11):11257-11266. doi: 10.1007/s11356-016-6318-9. Epub 2016 Feb 29.
Mosquitoes are rapidly developing resistance to insecticides that millions of people relied on to protect themselves from the diseases they carry, thereby creating a need to develop new insecticides. Clausena anisata is used traditionally as an insect repellent by various communities in Africa and Asia. For this study, the repellency and adulticidal activities of leaf extracts and compounds isolated from this plant species were evaluated against the yellow fever mosquito, Aedes aegypti. In the topical application assays, using total bites as an indicator, repellency was dose dependent, with the acetone crude extract (15 %) having 93 % repellence and the hexane fraction (7.5 %) 67 % repellence after 3 h. Fractionation resulted in a loss of total repellence. As mosquito-net treating agents, the acetone and hexane extracts of C. anisata, both at 15 %, had average repellences of 46.89 ± 2.95 and 50.13 ± 2.02 %, respectively, 3 h after exposure. The C. anisata acetone extract and its hexane fraction caused mosquito knockdown and eventually death when nebulised into the testing chamber, with an EC50 of 78.9 mg/ml (7.89 %) and 71.6 mg/ml (7.16 %) in the first 15 min after spraying. C. anisata leaf extracts have potential to be included in protection products against mosquitoes due to the repellent and cidal compounds contained therein.
蚊子正迅速对杀虫剂产生抗药性，而数百万人曾依赖这些杀虫剂来保护自己免受蚊子所携带疾病的侵害，因此有必要研发新型杀虫剂。非洲和亚洲的多个社区传统上使用山黄皮作为驱虫剂。在本研究中，对从该植物物种中分离出的叶提取物和化合物针对黄热病蚊子埃及伊蚊的驱避活性和杀成虫活性进行了评估。在局部应用试验中，以总叮咬次数为指标，驱避活性呈剂量依赖性，丙酮粗提物（15%）在3小时后具有93%的驱避率，己烷馏分（7.5%）在3小时后具有67%的驱避率。分级分离导致总驱避率下降。作为蚊帐处理剂，15%浓度的山黄皮丙酮提取物和己烷提取物在暴露3小时后的平均驱避率分别为46.89±2.95%和50.13±2.02%。将山黄皮丙酮提取物及其己烷馏分雾化到测试室中时，会导致蚊子击倒并最终死亡，在喷洒后的前15分钟内，其半数有效浓度（EC50）分别为78.9毫克/毫升（7.89%）和71.6毫克/毫升（7.16%）。由于山黄皮叶提取物中含有驱避和杀虫化合物，因此有潜力被纳入防蚊保护产品中。
