pediculicidal activity of foeniculum vulgare essential oil in treatment of pediculus capitis as a public health problem

Background: pediculosis, caused by pediculus spp is an important public health problem in urban and rural areasaround the world. natural compounds such as plant essential oils (eos) have been suggested as a potential alternativefor insect pest control recently. the purpose of this study was to investigate the toxicity of foeniculum vulgare essentialoil against the head louse, pediculus capitis under laboratory conditions.methods: fennel essential oil components were analyzed using gc-mass apparatus. immersion and contact filter paperbioassays were used to evaluate fennel essential oil toxicity at the two-fold concentrations of 2.5, 5, 10, 20, and 40%against nit and nymph/adult stages of the head louse.results: trans-anethole, α-thujone, and limonene, which consisted of 76.08%, 10.37%, and 5.34% were the most componentsof fennel oil respectively. the lc50 values for the adult /nymphs were 11.5, 6.4, 3.9, 3.1 and 2.5% and lc99values were 29.5, 15.2, 12.8, 10.8, and 7.4% at 10, 20, 30, 45 and 60 minutes after exposure respectively. the lethaltimes (lt50) for adults/nymphs were 5.2, 8.1, 9.5, 20.5, and 45.8 minutes and lt99 were 138.6, 91.3, 23.8, 21.7, and13.9 minutes in the concentrations of 2.5, 5, 10, 20 and 40%, respectively. lc50 and lc99 values were 2.32% and 7.36%after 5 days for the eggs.conclusion: fennel essential oil at the concentration of 15% after 20min is suggested to develop as an appropriate formulationto evaluate in clinical trials.