Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, Federal University of Agriculture, Ogun State, PMB 2240, Alabata, Abeokuta, Nigeria.
Nigeria Natural Medicine Development Agency, 9 Kofo Abayomi Street, Victoria Island, Lagos State, Nigeria.
Exp Appl Acarol. 2021 Feb;83(2):301-312. doi: 10.1007/s10493-020-00578-z. Epub 2021 Jan 3.
Ticks are of great economic importance to humans and animals due to their role in disease transmission. The application of synthetic, chemical acaricides on the animal and/or the environment (the most used tick control method globally) has led to the selection of tick populations that are resistant. Their adverse effects on ecology and human and animal health cannot be overemphasised. As a result, the search for alternatives that are natural and can overcome these adverse effects are strongly indicated. Using gas chromatography-mass spectrometry (GC-MS) and adult immersion test (AIT), this study evaluated the chemical composition and acaricidal activity, respectively, of Eucalyptus globulus essential oil (EO) on Rhipicephalus (Boophilus) annulatus ticks. This is a major tick species implicated for the transmission of bovine piroplasmosis in Nigeria. The acaricidal activity was evaluated using different concentrations (0.625, 1.25, 2.5, 5 and 10%) of E. globulus EO. Amitraz (1 and 2%) and cypermethrin (2%) served as the positive control and 2% dimethylsulfoxide in distilled water was the negative control. Three replicates of 10 engorged female ticks each were immersed in the test samples for 2 min and the experiment was done twice. The GC-MS analysis identified the major constituents of E. globulus EO as eucalyptol (1,8-cineole) (78%), menthol (20%) and menthone (3%). Eucalyptus globulus EO caused 97% acaricidal mortality at 10% concentration. The lower concentrations reduced tick fecundity up to 90% in a dose-dependent manner. This study provides support for plant EOs as alternative tick control strategy for humans and animals.
蜱虫因其在疾病传播中的作用而对人类和动物具有重要的经济意义。在动物和/或环境中应用合成的化学杀蜱剂（全球最常用的蜱控制方法）导致了抗蜱种群的选择。它们对生态和人类及动物健康的负面影响怎么强调都不为过。因此，强烈需要寻找天然的替代品来克服这些不利影响。本研究使用气相色谱-质谱联用仪（GC-MS）和成虫浸浴试验（AIT），分别评估了蓝桉精油（EO）的化学成分和杀蜱活性对 Rhipicephalus（Boophilus）annulatus 蜱的影响。这是一种在尼日利亚传播牛梨形虫病的主要蜱种。使用不同浓度（0.625、1.25、2.5、5 和 10%）的蓝桉 EO 评估杀蜱活性。使用 1%和 2%的双甲脒和 2%的氯菊酯作为阳性对照，2%二甲基亚砜在蒸馏水中作为阴性对照。每份测试样品各浸入 3 个 10 只已饱血的雌性蜱虫，浸泡 2 分钟，实验进行两次。GC-MS 分析确定了蓝桉 EO 的主要成分是桉叶醇（1,8-桉油精）（78%）、薄荷醇（20%）和薄荷酮（3%）。蓝桉 EO 在 10%浓度下可导致 97%的杀蜱死亡率。较低的浓度以剂量依赖的方式将蜱的生殖力降低了 90%。本研究为植物 EO 作为人类和动物替代蜱控制策略提供了支持。
