<i>In vitro</i> Effects of <i>Anogeissus leiocarpus</i> and <i>Adansonia digitata</i> on Two Life-cycle Stages of <i>Haemonchus contortus</i>, a Gastrointestinal Parasite of Small Ruminants

Abstract

This study evaluated the in vitro anthelmintic activity of aqueous and hydroethanolic extracts of Anogeissus leiocarpus and Adansonia digitata leaf powder at 75; 150; 300; 600; 1200 and 2400 µg/mL against H. contortus, using the egg hatch test and the adult worm motility inhibition test. For egg hatch inhibition, the both plants showed significant concentration-dependent efficacy and were significantly more effective (p < 0.001) at the highest concentrations (1200 and 2400 µg/mL) than at the lowest. The hydro ethanolic extract of A. leiocarpus showed the highest inhibition (R 2 = 0.9963) and the aqueous extract of the same plant showed the lowest inhibition (R 2 = 0.9742). The 50% inhibitory concentration (IC50) of the A. leiocarpus aqueous and hydro ethanolic extracts (86.19 and 72.5 µg/mL) were 3 times lower than those of the A. digitata extracts (302 and 269.5 µg/mL). Mobility of adult worms was also concentration dependent (p<0.05); and also dependent on incubation time (p<0.01). At 2400 µg/mL, all adult worms were immobile after 6 h of exposure, whereas at the lowest concentration (75 µg/mL), all adult worms were immobile after 36 h of exposure. Extracts from both plants had similar activity. Finally, the results of the present study suggest that the both plants studied have anthelmintic properties in vitro which would explain their use by livestock farmers. However, in vivo tests should be performed to confirm these properties in vivo as well.