Nanotechnology applied for the development of botanical acaricides and repellents against ticks of medical and veterinary importance.

Abstract

Ticks in general represent a great public health concern, since they cause considerable livestock losses and are vectors of many pathogens, such as bacteria, viruses, protozoa, and helminths, affecting domestic/wild animals and human beings as well. In this context, new tick control strategies have been explored, such as the use of chemical acaricides of natural origin, with active ingredients based on plants. Nanotechnology may be used as an alternative tool to improve the chemical properties and biological activity of natural products. In this scenario, this project aims to develop nanoformulations containing as active ingredients molecules obtained from Acmella oleracea (Jambu), Cymbopogon citratus (Lemongrass) and Lippia alba (Melissa) plants and to verify its effectiveness as acaricidal and repellent against larvae and adult ticks of medical and veterinary importance. The project intends to 1) investigate the acaricidal and repellent effect of nanoemulsions containing ethanolic extract of A. oleracea against larvae and adults of Ixodes scapularis, Dermacentor variabilis, and Amblyomma americanum; 2) to study the acaricidal and repellent activity of nanoemulsions containing essential oils of A. oleracea, C. citratus and L. alba and to verify the effects of the combination of these three oils (synergistic, antagonistic, or additive effect) against the same ectoparasites; 3) to verify the acaricidal and repellent properties of nanoemulsions containing spilanthol analogue, citral, and limonene, and to verify the effects of the combination of these three molecules (synergistic, antagonistic, or additive effect) against the same tick species; and 4) select the most effective formulations to be evaluated and applied to ticks of interest in livestock and public health in Brazil (Rhipicephalus microplus and Amblyomma sculptum ticks). (AU)