In vitro screening of plant extract on Haemonchus contortus and Rhipicephalus (Boophilus) microplus

The aim of this study was to perform in vitro screening of the antiparasitic potential of thirty-five plant extracts against the gastrointestinal nematode (GIN) Haemonchus contortus and the cattle tick Rhipicephalus microplus. The larval development test (LDT) and egg hatch test (EHT) were performed to assess the activity against GIN; and the larval packet test (LPT), larval repellency test (RT) and adult immersion test (AIT) were used to assess the acaricidal effect. In the EHT, the Senecio brasiliensis aqueous extract had the best IC50 value (1.2 mg.mL(-1)). In the LPT and AIT, Schinus lentiscifolius hexane extract presented best acaricidal effect, with 100% efficacy at 50 mg.mL(-1) and IC50 of 2.1 mg.mL(-1), respectively. In summary, S. brasiliensis demonstrated potential for the control of GIN, while S. lentiscifolius showed outstanding efficacy against cattle tick, therefore both have potential for future studies related to isolation of bioactive substances and toxicological and pre-clinical experiments.