薄荷油体外抗蠕形螨效果及杀螨机制

采用透明胶带粘贴过夜法获取2种人体蠕形螨,随机分组,观察不同浓度的薄荷油的杀虫效果,并在MoticDMB5图像采集软件系统下拍摄虫体在薄荷油作用下的虫体死亡过程。结果表明,薄荷油有很强的体外杀灭2种人体蠕形螨的作用,尤其对皮脂蠕形螨的杀灭作用显著。随着药物浓度的增加及作用时间的延长,蠕形螨死亡率增高。12.5%、3.125%分别是薄荷油体外杀灭毛囊蠕形螨和皮脂蠕形螨的最适杀螨浓度。薄荷油作用于蠕形螨,可见虫体收缩扭动,活动加剧,消化管剧烈收缩,毛囊蠕形螨和皮脂蠕形螨体壁均有渗出物外溢。虫体表现为兴奋—痉挛—失水—松弛—死亡的典型症状。薄荷油对人体蠕形螨的杀灭机制主要通过神经毒性和直接毒杀作用,造成虫体破裂脱水而死亡。薄荷油是一种极具开发潜能的高效的天然杀螨药。

The pesticidal effect and mechanism of peppermint oil in vitro against Demodex

The mites were collected with adhesive cellophane tape and then randomly divided into groups. The pesticidal effect of peppermint oil at different concentrations against Demodex was investigated. The morphologic change and activity of mites were pictured using Motic Images software. The results showed that peppermint oil had powerful killing effect for D. folliculorum and D.brevis in vitro, especially for D.brevis. The mortality increased with the drug concentration elevated and time prolonged. The most suitable and effective concentration against D. folliculorum in vitro was 12.5%,while the concentration for D.brevis was 3.125%. When the drug was given, the mites contracted and twisted with accelerated activity, both D. folliculorum and D.brevis had extravasated out from the body wall. The typical process for the mite toxicity was excite-spasm-dehydration-chalasia-die. The main action of peppermint oil is neurotoxicity and contact toxicity: it can result in the mite's dehydration and die. Peppermint oil is a natural and highly effective drug against human Demodex.