Eficácia in vitro de óleos essenciais de espécies de Piperaceae no controle do acantocéfalo Neoechinorhynchus buttnerae

Abstract

This study investigated the in vitro efficacy of essential oils (OEs) of four species of plants of the family Piperaceae, these being; Piper hispidinervum, Piper hispidum, Piper marginatum and Piper callosum, in the control of Neoechinorhynchus buttnerae acanthocephalus that affect tambaqui. The tested concentrations of OE were: 0.19; 0.39; 0.78; 1.56; 3.125; 6.25; 12.5; 25 and 50 mg.mL-1, in triplicate, into petri dishes containing 10 parasites per plate. In this in vitro assay, all OEs studied showed significant activity against the acanthocephal N. buttnerae. There was higher mortality of the parasites at the highest concentrations and times of exposure to the OEs tested. Effective concentrations of 50% (EC50) were obtained through probit analysis and evaluated according to the exposure time in 2, 6 and 24 hours. The OE of P. hispidinervum showed lower values of EC50 (0,56; 0,54 e 0,51 mg.mL-1) compared to the values obtained for Piper hispidum (EC50 de 5,44; 3,85 e 1,75 mg.mL-1), Piper marginatum (EC50 de 2,98; 1,3 e 1,27 mg.mL-1 ) and Piper callosum (EC50 de 2,66; 2,16 e 2,16 mg.mL-1).