Potential of plant extracts to inhibit egg hatching and migration of Haemonchus contortus larvae

Gastrointestinal parasitosis constitutes important health problems, aggravating throughout the years, due to inadequate use of drugs for its control, causing anthelmintic resistance. The objective of the present study was to evaluate the potential of Azadirachta indica (AZA) and Moringa oleifera (MOR) extracts in inhibiting egg hatching and in vitro migration of Haemonchus contortus larvae. A completely randomized design of experiment was carried out, where 15 treatments and a dimethyl sulfoxide negative control were evaluated: MOR-75, MOR-50, MOR-25, MOR-12.5, and MOR-6.25 mg/mL; AZA-75, AZA-50, AZA-25, AZA-12.5, and AZA-6.25 mg/mL; and thiabendazole (TBZ) TBZ-200, TBZ-100, TBZ-40, TBZ-20, TBZ-10 µg/mL. The extracts did not inhibit egg hatching capacity; however, we observed a motility decrease of up to 100% in L1 larvae. The extracts affected larval migration (P < 0.0020) compared with controls (dimethyl sulfoxide and TBZ), with migration rate inhibition above 65 %. Probit analysis showed that the median effective concentrations were 60.41 and 65.69 mg/mL for M. oleifera and A. indica, respectively. The in vitro results suggest that the water extract of both plants has an anthelmintic action against gastrointestinal nematode larvae.