Yones Doaa A, Bakir Hanaa Y, Bayoumi Soad A L
Parasitology Department, Faculty of Medicine, Assiut University, Assiut, 71526, Egypt.
Pharmacognosy Department, Faculty of Pharmacy, Assiut University, Assiut, 71526, Egypt.
Parasitol Res. 2016 Aug;115(8):3209-18. doi: 10.1007/s00436-016-5083-5. Epub 2016 Apr 25.
Natural compounds have been suggested as alternative sources for pediculosis capitis control. We aimed to investigate the chemical composition and evaluate the pediculicidal activity of spearmint, clove, cassia, thyme, eucalyptus, and anise essential oils in addition to sesame oil against human head lice in vitro. A filter paper contact bioassay method was used by applying 0.25 and 0.5 mg/cm(2) of each tested oil to filter paper in Petri dishes with 15 females head lice and another with ten nits. The lice mortalities were reported every 5 min for 180 min. The percentage of inhibition of hatch (PIH) was used to calculate ovicidal activity by daily microscopic inspections 5 days after the hatching of controls. Comparison with the widely used pediculicide (malathion) was performed. The most effective essential oil was spearmint followed by cassia and clove with KT50 values of 4.06, 7.62, and 12.12 at 0.5 mg/cm(2) and 8.84, 11.38, and 19.73 at 0.25 mg/cm(2), respectively. Thyme, eucalyptus, and anise were also effective adulticides with KT50 values of 18.61, 32.65, and 37.34 at 0.5 mg/cm(2) and 29.92, 43.16, and 45.37 at 0.25 mg/cm(2), respectively. Essential oils were also successful in inhibiting nymph emergence. Spearmint oil was the most effective, with a complete inhibition of emergence at 0.5 mg/cm(2). Sesame fixed oil did not show any adulticidal or ovicidal activity against head lice in vitro. The observed insecticidal activity was comparable to malathion. The results herein described the effectiveness of these essential oils as potential pediculicides for head lice control. Incorporation of essential oils in pediculicide formulations needs proper formulation and clinical trials.
天然化合物已被提议作为控制头虱的替代来源。我们旨在研究留兰香、丁香、桂皮、百里香、桉叶和茴芹精油以及芝麻油对人头虱的化学成分并评估其杀虱活性。采用滤纸接触生物测定法，将每种受试油以0.25和0.5毫克/平方厘米的剂量涂于培养皿中的滤纸上，每个培养皿中有15只雌性头虱和另一个有10颗虱卵。每隔5分钟记录180分钟内的虱子死亡率。通过在对照孵化5天后每日显微镜检查，使用孵化抑制百分比（PIH）来计算杀卵活性。与广泛使用的杀虱剂（马拉硫磷）进行了比较。最有效的精油是留兰香，其次是桂皮和丁香，在0.5毫克/平方厘米时的KT50值分别为4.06、7.62和12.12，在0.25毫克/平方厘米时分别为8.84、11.38和19.73。百里香、桉叶和茴芹也是有效的成虫杀虫剂，在0.5毫克/平方厘米时的KT50值分别为18.61、32.65和37.34，在0.25毫克/平方厘米时分别为29.92、43.16和45.37。精油在抑制若虫羽化方面也很成功。留兰香油最有效，在0.5毫克/平方厘米时完全抑制羽化。芝麻油在体外对人头虱没有显示出任何杀成虫或杀卵活性。观察到的杀虫活性与马拉硫磷相当。本文结果描述了这些精油作为潜在头虱控制杀虱剂的有效性。将精油纳入杀虱剂配方需要适当的配方和临床试验。
