Qiao Ye, Yu Zhijun, Bai Lingqian, Li Hao, Zhang Songbo, Liu Jingze, Gao Zhihua, Yang Xiaolong
Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
Ecotoxicol Environ Saf. 2021 Aug 17;224:112672. doi: 10.1016/j.ecoenv.2021.112672.
Chemical acaricides are mainly used in traditional tick control, which leads to the emergence of tick resistance and concurrently results in environmental pollution. In the present study, the chemical constituents of essential oils (EOs) from Thymus mongolicus, Cinnamomum verum, and Origanum vulgare was analyzed, and their potential application was evaluated to control the vector tick Haemaphysalis longicornis, which is widely distributed over vast areas of Eurasia, Australia, and New Zealand. Gas chromatography-mass spectrometry analysis revealed that the phenols thymol and carvacrol accounted for 34.66% and 75.72% of the EOs of T. mongolicus and O. vulgare, respectively, whereas trans-cinnamaldehyde (49.42%) was the main constituent of C. verum EO. Immersion tests showed that the EOs of C. verum and O. vulgare had significant acaricidal activity against larval H. longicornis, with the 50% lethal concentration (LC) being 16.07 and 18.02 mg/mL, respectively, and the 95% lethal concentration (LC) being 120.37 and 130.09 mg/mL, respectively. The EOs of O. vulgare and T. mongolicus showed significant acaricidal activity against unfed adult H. longicornis, with LC being 43.50 and 44.21 mg/mL, respectively, and LC being 113.66 and 137.99 mg/mL, respectively. The fumigant toxicity test showed significant acaricidal activity of the three EOs against both unfed and engorged nymphal and adult H. longicornis. Enzyme assays revealed that the EOs of both C. verum and O. vulgare significantly inhibited glutathione S-transferase activity (P < 0.05). In contrast, the activities of carboxylesterase and multifunction oxidases were significantly inhibited by EOs extracted from all three plants (P < 0.05). Taken together, these findings suggest that plant EOs may serve as an environment-friendly alternative for synthetic acaricides in future tick control.
化学杀螨剂主要用于传统的蜱虫防治，这导致了蜱虫抗药性的出现，同时还造成了环境污染。在本研究中，对百里香、肉桂和牛至精油的化学成分进行了分析，并评估了它们在控制媒介蜱长角血蜱方面的潜在应用，长角血蜱广泛分布于欧亚大陆、澳大利亚和新西兰的广大地区。气相色谱 - 质谱分析表明，百里香酚和香芹酚分别占百里香和牛至精油的34.66%和75.72%，而反式肉桂醛（49.42%）是肉桂精油的主要成分。浸泡试验表明，肉桂和牛至的精油对长角血蜱幼虫具有显著的杀螨活性，50%致死浓度（LC）分别为16.07和18.02毫克/毫升，95%致死浓度（LC）分别为120.37和130.09毫克/毫升。牛至和百里香的精油对未吸血的长角血蜱成虫具有显著的杀螨活性，LC分别为43.50和44.21毫克/毫升，LC分别为113.66和137.99毫克/毫升。熏蒸毒性试验表明，这三种精油对未吸血和饱血的若虫及成虫长角血蜱均具有显著的杀螨活性。酶活性测定表明，肉桂和牛至的精油均显著抑制谷胱甘肽S - 转移酶活性（P < 0.05）。相比之下，从这三种植物中提取的精油均显著抑制羧酸酯酶和多功能氧化酶的活性（P < 0.05）。综上所述，这些发现表明植物精油在未来蜱虫防治中可能作为合成杀螨剂的环保替代品。
