Efficacy of a Combination of Emodepside plus Praziquantel against Larval and Adult Stages of Nematodes (Trichuris muris, Angiostrongylus cantonensis) in Rodents

摘要

A combination of emodepside plus praziquantel was tested in laboratory mice strain C57BL/10 experimentally infected with Trichuris muris. Under the conditions chosen, a single topical administration of 3.0 mg emodepside per kg of body weight (bw) and 12.0 mg praziquantel per kg bw at day 52 led to a survival rate of 6.8% of mature T. muris at 54 day post infection (dpi). Using the same dose at 3 dpi, the survival rate of mature nematodes at 52 dpi was 84.7%. However, when single treatment with 3.0mg emodepside per kg bw plus 12.0 mg praziquantel per kg bw was used at 20 dpi or 35 dpi, the survival rates of adult nematodes on day 52 were 15.7 or 18.8%, respectively. Following a single administration of 6 mg emodepside per kg bw and 24 mg praziquantel per kg bw at 3, 20 and 35 dpi the survival rates of mature T. muris were 1.7, 0.6 or even 0%. In another series of experiments, emodepside plus praziquantel were tested inWistar rats experimentally infected with Angiostrongylus cantonensis. Following a treatment at day 15 p.i. with either 3.0 or 6.0mg emodepside per kg bw and either 12.0mg or 24.0mg praziquantel per kg bw, respectively, the survival rates of adult nematodes at 44 dpi were not significantly reduced in comparison to the untreated controls. Only when single treatment was done with the highest dose with 18 mg emodepside per kg bw and 72 mg praziquantel per kg bw was the survival rate of larvae migrating in the CNS reduced to 32.4%at 20 dpi. A complete depression of the survival rate of adult A. cantonensis was observed following single treatment with 12.0 or 18.0 mg emodepside per kg bw and 48.0 or 72.0 mg praziquantel per kg bw at 15 dpi when the control (killing and examination) was done at 44 dpi. The single standard dose of 3 mg emodepside per kg bw and 12 mg praziquantel per kg bw, either administered at 15 or at 44 dpi, reduced the survival rate of adult A. cantonensis to 54.2 or 67.6% at 44 or 52 dpi, respectively. The present paper shows for the first time the efficacy of a combination containing emodepside plus praziquantel against the nematodes T. muris and A. cantonensis.