Comparative toxicity of oxygenated monoterpenoids in experimental hydro-alcoholic lotions. Correlation with physical parameters

PAOLA GONZÁLEZ AUDINO, C. VASSENA, G. MOUGABURE CUETO, A. TOLOZA, A. GALLARDO & M.I. PICOLLO

Urgup, Cappadocia

Congreso; 9. Fourth International Conference on Phthiraptera (ICP4); 2010

International Society of Phthirapterists

The use of botanical compounds such as essential oils has recently become of great interest as a natural mean of pest control because of its repellent, ovicidal, adulticidal and feeding inhibition activity against various insect species including head lice. Essential oils are the steam-distillable fraction of plant tissues which are often responsible for a plant’s distinctive scent, odour or taste. These oils are of rather complex composition, generally consisting of low molecular weight monoterpenes and related phenols. Due to the variability of their constitution the effects may not be reliable, safe and reproducible. Thus, it was our objective to test and compare the efficacy of pure oxygenated monoterpenoids which are main ingredients of essential oils that have proved good biological activity. We used pulegon and citral, components of Aloysia citrodora, and geraniol, citronelol, eugenol, mentol and linalool, components of geranium oil. The toxic activities were evaluated by the immersion method of head lice in hidro-alcoholic solutions. We tested ethanolic solutions from 0 to 70% and monoterpenoid concentrations from 0.05 to 10%. As end point we evaluated both inactivation and mortality of head lice. We found that citronelol and geraniol showed the highest mortality (>60%). Pulegone, linalool, mentol and citral produced inactivation between 42 and 55%, and mortality between 34 and 53%. A simple linear regression analyses showed statistically significant relationships between the toxic effects and viscosity of the monoterpenoids (p<0.05) but no with their log P.