Anticholinesterase and pediculicidal activities of monoterpenoids

• Published in: Fitoterapia 2008-06, Vol.79 (4), p.271-278
• Main Authors: Picollo, M.I., Toloza, A.C., Mougabure Cueto, G., Zygadlo, J., Zerba, E.
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase; Acetylcholinesterase - metabolism; Animals; Biological and medical sciences; Cholinesterase Inhibitors - chemistry; Cholinesterase Inhibitors - pharmacology; Cyclohexanols - chemistry; Cyclohexanols - pharmacology; Dose-Response Relationship, Drug; Electrophorus; General pharmacology; Head lice; Inhibition; Insecticides - chemistry; Insecticides - pharmacology; Medical sciences; Monoterpenes - chemistry; Monoterpenes - pharmacology; Monoterpenoids; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Phthiraptera - drug effects; Time Factors
• ISSN: 0367-326X
• DOI: 10.1016/j.fitote.2008.01.005

The repetitive and inadequate application of pediculicidal products frequently results in the development of resistance to these compounds. Essential oils are a promising alternative to synthetic insecticides, although their mode of action remains to be explored. It has been proposed that one possible target of the essential oils is the inhibition of acetylcholinesterase (AChE). The role of monoterpenoids as possible AChE inhibitors and their relationship with the toxicity was investigated both in vitro and in vivo. Inhibition of electric eel AChE activity showed that the most effective inhibitor was 1,8-cineole with IC 50 6 × 10 − 3  M. The inhibition of AChE activity of head louse homogenate by 1,8-cineole showed IC 50 7.7 × 10 − 2  M. The intoxication symptoms of head lice exposed to vapors of 1,8-cineole was recorded before the in vivo head louse AChE inhibition assay. No correlation was found between neurotoxic symptoms and inhibition of AChE activity.