Antiparasitic and antimicrobial activity of spilanthol: study of the effects on ticks of medical and veterinary importance and against pathogens transmitted by them

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. The widely used method to control ticks is the use of synthetic chemical acaricides. However, the indiscriminate use of such products can induce the selection of resistant ticks and lead to the accumulation of chemical residues in the environment, contaminating the soil and water streams, and consequently affecting other animals, including human beings. Among the new strategies that have been proposed to control ticks is the use of compounds of natural origin, such as the Acmella oleracea plant, popularly known as Jambu, which has a known acaricide potential. In this way, the objective of the present study will be to verify the antiparasitic potential of the spilanthol analogue (synthetic molecule) against ticks Rhipicephalus microplus and Amblyomma sculptum, as well as its antimicrobial potential against obligatory intracellular pathogens of medical and veterinary importance, using as a model the bacterium E. minasensis. In order to achieve the objectives, will be performed testes of mortality and repellent on larvae; mortality tests, reproductive parameters and morphological analyses of the female reproductive system (morphophysiological analyses and quantification of cell death processes), in vivo tests and semi-field conditions; MTT assays and real-time polymerase chain reaction (qPCR) to evaluate the antimicrobial potential of the product. The results will provide information relevant for the development of sustainable strategies to control these ticks. (AU)