Acaricidal activity of extract from Eupatorium adenophorum against the Psoroptes cuniculi and Sarcoptes scabiei in vitro

The possible acaricidal activity of Eupatorium adenophorum was analyzed using extracts created by water decocting, ethanol thermal circumfluence, and steam distillation. The toxic effect of each extract was tested against Psoroptes cuniculi and Sarcoptes scabiei in vitro. Ethanol thermal circumfluence extract had strong toxicity against mites, killing all S. scabiei at 0.5 and 1.0 g/ml (w/v) concentration, while 1 g/ml extract was also found to kill all P. cuniculi within a 4-h period. Similarly, 0.25, 0.5 and 1.0 g/ml concentration of extract had strong toxicity against S. scabiei, with median lethal time (LT50) values at 0.866, 0.785 and 0.517 h, respectively. 0.5 g/ml and 1 g/ml showed strong acaricidal action against P. cuniculi; the LT50 values were 0.93 h and 1.29 h, respectively. The median lethal concentration (LC50) values were 0.22 g/ml for Scabies mite and 0.64 g/ml for P. cuniculi in 1 h. The results indicated that E. adenophorum contains potent acaricidal ingredients; as a first step in the potential development of novel drugs, it may provide new acaricidal compounds for the effective control of animal acariasis.