Abstract

Background:
Gastrointestinal nematodes are a major impediment to the health and productivity of small ruminants. Studies have examined the effects of anthelmintic resistance and herbal medicines on sheep and goat farms. Sweet potato (Ipomoea batatas) is a revenue-generating agricultural product that provides medicinal properties and secondary metabolites.

Aim:
This study aimed to assess the potential of sweet potato leaves as a natural anthelmintic by quantifying the concentrations of secondary metabolites in mountainous and coastal areas. In vitro studies were conducted to examine the effects of sweet potato leaf aqueous extract (A.E.I.) on the viability of H. contortus, egg hatching inhibition (EHI), and surface ultrastructure alteration.

Methods:
Sweet potato leaves were collected from two sites. The leaves were selected, washed, and dried. The total flavonoid, saponin, tannin, alkaloid, and steroid concentrations were analyzed using a UV-Vis spectrophotometry. In vitro tests were performed using A.E.I. and the EHI test against female H. contortus. SEM was used to observe the ultrastructure of adult worm skin exposed to the extract.

Results:
Variations in secondary metabolite concentrations were observed in cultivated in coastal and mountainous regions. Sweet potato leaves from the mountains have higher levels of flavonoids, alkaloids, tannins, and saponins than those from coastal areas. In contrast, coastal plants have higher levels of steroid. An in vitro study revealed that 100 mg/mL A.E.I. was almost as effective as 2 mg/mL albendazole after 3 h and equal after 4 h. Furthermore, the LHI test showed an 81% inhibitory effect on egg hatching. The length of treatment and A.E.I. concentration had a statistically significant effect on the H. contortus mortality rate. The SEM results illustrated the differences in the cutaneous appearance of the worm groups. The surface alterations were characterized by a rough, wrinkled, and irregular cuticle surface structure, as well as the presence of damage, indicating the anterior cuticle layer’s vulnerability.

Conclusion:
Sweet potato plants grown in mountainous and coastal areas have varying levels of phytochemical compounds known to have anthelmintic effects, including flavonoids, alkaloids, tannins, saponins, and steroids. A.E.I. exhibited anthelmintic effects against H. contortus. Ultrastructural changes were observed on the rough, wrinkled surface with irregular cuticle structure and the occurrence of damage, indicating the anterior and posterior cuticle structures were vulnerable.

Key words: Anthelmintic; Aqueous extract; Ipomoea batatas; Secondary metabolites; In vitro.