title: In vitro activity of Artemisia annua L (Asteraceae) extracts against Rhipicephalus (Boophilus) microplus.
abstract: The activity of plant extracts on parasites may indicate groups of substances that are potentially useful for controlling Rhipicephalus (Boophilus) microplus. The aim of the present study was to investigate the in vitro action of Artemisia annua extracts on this tick. The concentrations of the sesquiterpene lactones artemisinin and deoxyartemisinin present in plant extracts were quantified via high-performance liquid chromatography. Four extracts produced from the concentrated crude extract (CCE) were evaluated on larvae using the impregnated paper method, with readings after 24 hours of incubation. The engorged females were immersed in the CCE and in its four derived extracts for five minutes, with incubation for subsequent analysis of biological parameters. The extracts were not effective on the larvae at the concentrations tested (3.1 to 50 mg.mL(-1)). The CCE showed greater efficacy on engorged females (EC(50) of 130.6 mg.mL(-1) and EC(90) of 302.9 mg.mL(-1)) than did the derived extracts. These results tend to confirm that the action of artemisinin on engorged females of R. (B.) microplus is conditional to their blood intake. In this case, in vitro methods would be inadequate for effective evaluation of the action of A. annua on R. (B.) microplus.
authors: Laboratório de Sanidade Animal, Embrapa Pecuária SudesteRod. Washington Luiz, São Carlos, Brazil. carolina@cppse.embrapa.br
authors: Ana Carolina de Souza
authors: AC
authors: Chagas
authors: Cynthia Sanches
authors: CS
authors: Georgetti
authors: Camila Olivo de
authors: CO
authors: Carvalho
authors: Márcia Cristina de Sena
authors: MC
authors: Oliveira
authors: Rodney Alexandre
authors: RA
authors: Rodrigues
authors: Mary Ann
authors: MA
authors: Foglio
authors: Pedro Melillo de
authors: PM
authors: Magalhães
mesh_terms: D000818:Animals; D031172:Artemisia annua; D010936:Plant Extracts / Q000494:pharmacology*; D048494:Rhipicephalus / Q000187:drug effects*; D013983:Tick Control
chemical_list: D010936:Plant Extracts