Plant Essential Oils: Toxicity of Individual and Mixed Components

M.I. PICOLLO

Utah

Congreso; 13. 5th International Conference on Phthiraptera (ICP5). Canyons Resort in Park City; 2014

International Society of Phthiraptera

Plant essential oils have been suggested as an alternative for thecontrol of insecticide-resistant headlice. Our first studies demonstrated the fumigant properties of theindividual components of essential oils from Argentinian native and exoticplants, and assessed a significant correlation between the insecticide activityand the vapor pressure. Other studies demonstrated an association between arange of viscosity of the individual component and the contact toxicity. Recentstudies revealed that the contribution of each constituent to the effect of ablend is partially determined by the toxic interactions with the otherconstituents of the oil. For example, the toxicity of artificial mixtures onlycontaining the major constituents of the geranium oil in the same proportion asthe natural oil (citronellol 38%, geraniol 16%, citronellyl formate 10.4% andlinalool 6.45%), was greater than whole oil and greater than each individualcomponent. Moreover, the removal of any four constituent produced a decrease ineffectiveness of the mixture, suggesting a synergism between major components. Theknowledge of the role of each constituent in the toxicity of the whole oilgives the possibility to create artificial blends for the development of moreeffective control agents. As an example, a binary formulation based onsynergized mono-terpenoids (NOPUCID®) was developed and actually marketed byELEA Laboratory in Argentina.