Anthelminthic Activity of <i>Moringa oleifera</i> Leaf Extracts Evaluated <i>in Vitro</i> on Four Developmental Stages of <i>Haemonchus contortus</i> from Goats

Abstract

Haemonchus contortus is a blood-sucking abomasal helminth of small ruminants responsible for major economic losses to small farmers worldwide. Widespread resistance to synthetic anthelminthics has stimulated a need for alternative strategies of parasite control, among which is the use of medicinal plants with natural anthelminthic properties. This study assessed in vitro the efficacy of infused and macerated aqueous extract as well ethanolic extract of Moringa oleifera against fresh eggs, embryonated eggs, L 1 and L 2 larvae of H. contortus . For this purpose, five different concentrations (0.625, 1.25, 2.5, 3.75 and 5 mg/ml) were prepared from dry extracts via serial dilutions with distilled water. Fresh eggs obtained from artificially infected goat feces were exposed to these different concentrations for 48 hours, while embryonated eggs and larvae were exposed for 6 and 24 hours respectively. Distilled water and 1.5% DMSO were used as negative control. The results were expressed in terms of mean inhibition percentage of egg embryonation, mean inhibition percentage of egg hatch and mean percentage of larval mortality. An overview of results revealed that ethanolic leaf extract of M. oleifera was most efficient on eggs by inhibiting 60.3% ± 8.2% and 92.8% ± 6.2% eggs embryonation at 3.75 and 5 mg/ml respectively with a significant difference (P < 0.05), which contributed to obtaining the lowest LC 50 value of 0.985 mg/ml. This extract also inhibited 99% ± 2% egg hatching of H. contortus at 5 mg/ml with an LC 50 value of 1.7 mg/ml. Concerning activity on larvae, the ethanolic extract was also most potent against them by inducing 98.8% ± 2.5% and 100% ± 0% mortality of L 1 and L 2 larvae at 5 mg/ml respectively. Infused aqueous extract was more efficient on eggs than on larvae with an IC 50 value less than 2 mg/ml and an LC 50 value more than 3.5 mg/ml. Macerated aqueous extract showed good activity against the four developmental stages with LC 50 values ranging from 2.08 mg/ml for L 2 larvae to 2.92 mg/ml for L 1 larvae and 2.37 to 2.52 mg/ml for embryonated and fresh eggs respectively. The current study showed that all three extracts of M. oleifera tested possessed potential ovicidal and larvicidal activities against H. contortus . However, further in vivo studies are necessary to validate the anthelminthic property of this plant.