Phytochemical screening and in vitro anthelmintic activity of methanolic extract of Terminalia glaucescens leaf on Haemonchus contortus eggs

Abstract Helminth infections remain a major constraint to livestock productivity in the tropical and subtropical areas across the world, especially in the areas where extensive grazing is practiced. The development of resistance to anthelmintic drugs, scarcity and high cost of purchase especially to farmers of low income in developing countries led to the need of alternative helminth control methods. However, there is an urgent need to discover novel drugs that can cure helminthiasis. A survey was carried out among agropastoralists to elicit information on the use of Ethnoveterinary Plants (EvPs) as alternative medicine for helminthiasis. The plants used by the agropastoralists were collected and identified at the Department of Botany Herbarium, University of Ibadan. The plant part was pulverized and cold macerated successively with n-hexane, ethyl acetate, methanol and aqueous methanol to obtain crude extracts. The methanolic extract was assayed against Haemonchus contortus at test concentrations (6.25, 12.5, 25, 50 and 100 µg/mL) and Albendazole at 25µg/mL were tested for the egg hatch inhibition assay. Eggs hatched and unhatched were counted under the microscope at 48, 96 and 144 hours (h). Among the EvPs identified, Terminalia glaucescens was the least utilized plant by the agropastoralists, and thus, selected for evaluation. The preliminary phytochemical screening revealed presence of tannin, alkaloid, saponin, flavonoid, phenolic, steroids, glycosides, triterpenes and reducing sugars. At 96 h, there were significant difference (P 0.05) differences observed in EHI values of methanolic extract of the leaf at 100ug/mL (89.69), 50ug/mL (87.06), 25ug/mL (85.53) and 12.5µg/mL (82.89) at IC50 value 1.08 compared to 25ug/mL (100) for the Albendazol. T. glaucescens leaf is a potential source of novel anthelmintics and further investigation should be carried out on its in vivo anthelmintic activity.