Ngaradoum O, Kagira JM, Karanja SM, Kipyegon K, Maina N
Haemonchus contortus is one of the most pathogenic nematode parasites in small ruminants’ worldwide. Anthelmintic resistance and high cost of drugs has prompted evaluation of medicinal plant extracts which can be used as alternative drugs. The objective of this study was to evaluate in vitro ovicidal and larvicidal activity of aqueous and methanolic extracts of Ziziphus mucronata barks against H. contortus stages isolated from a sheep in Kenya. Barks of Z. mucronata were collected from Chad, air-dried, ground and extracted with methanol and distilled water. The crude extracts were qualitatively screened for phytochemicals using standard methods. The anthelmintic activities of the extracts were evaluated using the egg hatch assay and larval mortality assay. The percentage extraction yields for methanol aqueous and aqueous methanol were 4.5% and 2.6%, respectively. The phytochemicals found in both extracts were saponins, tannins, glycosides, flavonoids and steroids. The results showed that methanolic extract had a significantly (p<0.05) higher activity with IC50 value of 3.9 mg/ml as compared with aqueous extract which had IC50 value of 14.7 mg/ml. In larval mortality assay, the methanolic extract had significantly (p<0.05) higher EC50 (7.5 mg/ml) than that of aqueous extract (2.7 mg/ml). The effects of Albendazole on egg hatchability inhibition and larval motility was significantly (p<0.05) higher than that of the two extracts. All the assays showed extract concentration dependent response. In conclusion, this study has shown that Z. mucronata extracts have anthelmintic activity on eggs and larvae of H. contortus parasite. The activity could be related to the presence of phytochemicals such as saponins and tannins. The effects of larval mortality were higher compared to that of egg hatchability. Therefore, extracts from Z. mucronata can be developed further as novel anthelmintic drug for control of H. contortus and hence improve production of small ruminants.
