In Vitro and In Vivo Evaluation of antihelmintic activity of essential oils from plants of families ASTERACEAE, LAMIACEAE AND RUTACEAE against Haemonchus contortus.

Abstract

Sheep farming is in general a rustic model of livestock present in Brazil since the colonial period. Economical and social relevancies of this livestock activity are highlighted in some regions of the country. Despite a marked overall progress in the last decades, infections with the gastrointestinal parasite H. contortus represent one the most important problems in sheep production, annoyed by the increasing resistance of nematodes to traditional anthelmintic drugs. This reality encouraged biotechnology research for continued evaluation of natural products or their derivatives for development of new conventional drugs or phytotherapical anthelmintic alternatives, especially when in advantage of efficacy, cost and safety in relation to traditional antihelmintic therapeutic arsenal. The aim of this work is to perform a phytochemical characterization of essentials oils extracted from plants of botanical families Asteraceae, Lamiaceae, and Rutaceae, which were selected following well defined etnopharmacological and chemotaxonomic criteria, as well as to evaluate their anthelmintic activity by in vitro assays against eggs, larval and adult forms of the H. contortus, which is followed by in vivo experiments involving artificially infected animals and the pharmaceutical development of a commercial product. Our experimental strategy aimed to test in vitro predeceasing in vivo assays is rational because brings a shortening in time and cost, and also is advantageous in terms of an ethical view by use of a lesser number of animals in in vivo experimental protocols.