Toxicity of Individual and Mixed Components

PICOLLO M.I.

Park City, Utah

Congreso; 5th International Conference on Phthiraptera (ICP5); 2014

University of Utah

Plant essential oils have been suggested as an alternative for the control of insecticide-resistant head lice. Our first studies demonstrated the fumigant properties of the individual components of essential oils from Argentinian native and exotic plants, and assessed a significant correlation between the insecticide activity and the vapor pressure. Other studies demonstrated an association between a range of viscosity of the individual component and the contact toxicity. Recent studies revealed that the contribution of each constituent to the effect of a blend is partially determined by the toxic interactions with the other constituents of the oil. For example, the toxicity of artificial mixtures only containing the major constituents of the geranium oil in the same proportion as the natural oil (citronellol 38%, geraniol 16%, citronellyl formate 10.4% and linalool 6.45%), was greater than whole oil and greater than each individual component. Moreover, the removal of any four constituent produced a decrease in effectiveness of the mixture, suggesting a synergism between major components. The knowledge of the role of each constituent in the toxicity of the whole oil gives the possibility to create artificial blends for the development of more effective control agents. As an example, a binary formulation based on synergized mono-terpenoids (NOPUCID®) was developed and actually marketed by ELEA Laboratory in Argentina.