Acaricide activity of leaves extracts of Sambucus australis Schltdl. (Caprifoliaceae) at 2% on engorged females of Rhipicephalus (Boophilus) microplus

Parasite infections caused by Rhipicephalus (Boophilus) microplus are responsible for the most of economic losses in producing-cattle countries in tropical and subtropical areas. Indiscriminate uses of chemical acaricides have contributed with the appearance of tick resistance to many drugs available in the marketplace, and it is a serious problem in the tick control. Flowers of Sambucus australis (South America), called "sabugueiro-from-Brazil", are used on infusions or decoctions forms in the folk medicine with diuretic, antipyretic, anti-inflammatory, and laxative purpose, also employed for treating respiratory diseases in human. The main goal of this study was to evaluate in vitro potential of S. australis leaves extracts as an acaricide agent. Ethanol extract at 70% has been dehydrated and a fraction was suspended in 70% ethanol or in distillated water at final concentration of 2% (0.2mg-1). Using the immersion test of engorged females the efficiency results were obtained in 34% and 66% with the leaves extract diluted in water and 70% ethanol, respectively. This study is the first report on acaricidal activity of S. australis against cattle tick. Further studies to determine the active metabolites in different stages of S. australis could aid to identify suitable extracts to be tested in the R. (B.) microplus control.