The anthelmintic effect of plant extracts on Haemonchus contortus and Strongyloides venezuelensis

a b s t r a c t The indiscriminate use of anthelmintics has resulted in the establishment of parasite resis- tance. Thus, this study aimed to evaluate the in vitro antiparasitic effect of plant extracts on Haemonchus contortus in sheep and the in vivo effect on Strongyloides venezuelensis in Rattus norvegicus. The plant extracts from Piper tuberculatum, Lippia sidoides, Mentha piperita, Hura crepitans and Carapa guianensis, produced at different research institutions, were chemically analyzed and evaluated through the egg hatch test (EHT) and larval development test (LDT) in H. contortus. P. tuberculatum (150 and 250 mg kg −1 of body weight) was evaluated for its anthelmintic action on R. norvegicus experimentally infected with S. venezuelensis. In the EHT, the LC50 and LC90 of the extracts were respectively as follows: 0.031 and 0.09 mg mL −1 for P. tuberculatum, 0.002 and 0.04 mg mL−1 for L. sidoides, 0.018 and 0.03 mg mL−1 for M. piperita, 0.36 and 0.91 mg mL −1