THE ROLE OF THE MONO-OXYGENASES IN THE DETOXIFICATION OF THE INSECTICIDES 1,8-CINEOLE AND DDVP IN PEDICULUS HUMANUS CAPITIS

TOLOZA AC, PICOLLO MI

Conferencia; Fourth International Conference on Phthiraptera (ICP4); 2010

National Journal of Turkish Society for Parasitology

During past decades, chemical control against the head louse Pediculus humanus capitis De Geer, has been based in the application of products containing permethrin. The repetitive overuse of pediculicides has resulted in the development of high levels of resistance to one or more of these products worldwide. Nowadays, there is a trend in the use of alternative insecticides like the essential oils obtained from aromatic plants. In an afford to find effective tools to reduce pyrethroid-resistant head lice populations, we studied the synergistic effect of the piperonyl butoxide (PBO) on the pediculicidal activity of the 1,8-cineole and the organophosphate DDVP. The head lice population used in our study had a resistant ratio of 40. Moreover, part of this resistance is due to the increased enzymatic activity of the cytochrome P450. The methodology employed here consisted of the topical application of the PBO on lice, followed by the exposition to the vapor phase of the compounds. The addition of PBO increased significantly the toxicity of either 1,8-cineole or DDVP. The present study indicates the importance of the microsomal monooxygenases (cytochrome P450) in the degradation of the monoterpenes like the 1,8-cineole. This suggests that a possible combination of monoterpenes or phytochemicals with PBO into a formulation might provide a better control to insecticide-resistant populations of head lice.