Govindarajan Marimuthu, Rajeswary Mohan, Hoti S L, Bhattacharyya Atanu, Benelli Giovanni
Unit of Vector Control, Phytochemistry and Nanotechnology, Department of Zoology, Annamalai University, Annamalai Nagar, 608002, Tamil Nadu, India.
Regional Medical Research Centre, Nehru Nagar, Belgaum, 590010, Karnataka, India.
Parasitol Res. 2016 Feb;115(2):807-15. doi: 10.1007/s00436-015-4809-0. Epub 2015 Oct 31.
Mosquito-borne diseases represent a deadly threat for millions of people worldwide. Eco-friendly mosquitocides are a priority. In Ayurvedic medicine, Plectranthus species have been used to treat heart disease, convulsions, spasmodic pain and painful urination. In this research, we evaluated the acute toxicity of essential oil from Plectranthus barbatus and its major constituents, against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. The chemical composition of P. barbatus essential oil was analyzed by gas chromatography-mass spectroscopy. Nineteen components were identified. Major constituents were eugenol (31.12%), α-pinene (19.38%) and β-caryophyllene (18.42%). Acute toxicity against early third-instar larvae of An. subpictus, Ae. albopictus and Cx. tritaeniorhynchus was investigated. The essential oil had a significant toxic effect against larvae of An. subpictus, Ae. albopictus and Cx. tritaeniorhynchus, with 50% lethal concentration (LC50) values of 84.20, 87.25 and 94.34 μg/ml and 90% lethal concentration (LC90) values of 165.25, 170.56 and 179.58 μg/ml, respectively. Concerning major constituents, eugenol, α-pinene and β-caryophyllene appeared to be most effective against An. subpictus (LC50 = 25.45, 32.09 and 41.66 μg/ml, respectively), followed by Ae. albopictus (LC50 = 28.14, 34.09 and 44.77 μg/ml, respectively) and Cx. tritaeniorhynchus (LC50 = 30.80, 36.75 and 48.17 μg/ml, respectively). Overall, the chance to use metabolites from P. barbatus essential oil against mosquito vectors seems promising, since they are effective at low doses and could be an advantageous alternative to build newer and safer mosquito control tools.
蚊媒疾病对全球数百万人构成致命威胁。环保型杀蚊剂是当务之急。在阿育吠陀医学中，香茶菜属植物已被用于治疗心脏病、惊厥、痉挛性疼痛和尿痛。在本研究中，我们评估了毛喉鞘蕊花精油及其主要成分对疟疾媒介亚致倦按蚊、登革热媒介白纹伊蚊和日本脑炎媒介三带喙库蚊幼虫的急性毒性。采用气相色谱-质谱联用仪分析了毛喉鞘蕊花精油的化学成分。共鉴定出19种成分。主要成分为丁香酚（31.12%）、α-蒎烯（19.38%）和β-石竹烯（18.42%）。研究了对亚致倦按蚊、白纹伊蚊和三带喙库蚊初孵三龄幼虫的急性毒性。该精油对亚致倦按蚊、白纹伊蚊和三带喙库蚊幼虫具有显著的毒性作用，半数致死浓度（LC50）值分别为84.20、87.25和94.34μg/ml，90%致死浓度（LC90）值分别为165.25、170.56和179.58μg/ml。关于主要成分，丁香酚、α-蒎烯和β-石竹烯似乎对亚致倦按蚊最有效（LC50分别为25.45、32.09和41.66μg/ml），其次是白纹伊蚊（LC50分别为28.14、34.09和44.77μg/ml）和三带喙库蚊（LC50分别为30.80、36.75和48.17μg/ml）。总体而言，使用毛喉鞘蕊花精油代谢产物对抗蚊虫媒介的前景似乎很广阔，因为它们在低剂量下有效，并且可能是构建更新、更安全的蚊虫控制工具的有利替代品。
