In vitro anthelmintic activity of Albizia gummifera, Crotalaria axillaris, Manilkara discolor, Teclea trichocarpa and Zanthoxylum usambarense using sheep nematodes

Abstract

Background: Albizia gummifera, Crotalaria axillaris, Manilkara discolor, Teclea trichocarpa and Zanthoxylum usambarense are used to treat different ailments in many parts of the world. For instance, A. gummifera is used to treat stomach pains, malaria, diarrhoea and sleeping sickness while C. axillaris treats ophthalmic disorders and kidney problems. Manilkara discolor stem bark infusion is used to treat stomach disorders and as an astringent while T. trichocarpa has been used to treat malaria, helminth infections and fever. Zanthoxylum usambarense is used to treat rheumatism, backache, painful joints, fever, sore throat, tonsillitis, chest pains, malaria, abscesses and wounds.

Objective: The aim was to determine whether the crude plant extracts have in vitro anthelmintic activity.

Materials and methods: Different parts of the plants were acquired from Ngong Hills forest, Kajiado County, Kenya in May 2012, dried and macerated to exhaustion with dichloromethane: methanol (1:1, v/v) solution. Nematode eggs (Haemonchus Spp, Trichostrongylus Spp and Oesophagostomum Spp) were obtained from infected sheep rectums at Department of Vet Farm, University of Nairobi based at Kabete. Varying concentrations of water solutions of the dry crude extracts were prepared. Egg hatch (EHA) and larvae development assays (LDA) were used to test the extracts’ effects on nematode egg hatching and larvae development, respectively

Results: Albizia gummifera (root bark) and Zanthoxylum usambarense (stem bark) showed high activity (IC50 below 300 μg / mL) in both tests. Albizia gummifera (root, stem bark and pods), Zanthoxylum usambarense root bark, Crotalaria axillaris twigs and Teclea trichocarpa root and stem bark showed high activity in LDAbut moderate activity (300 μg / mL < IC50 < 500 μg / mL) in EHA. Teclea trichocarpa twigs showed moderate activity in LDA but low (IC50 > 500 μg / mL) activity in EHA. Manilkara discolor extracts showed low activity in both tests.

Conclusion: Different extracts of the plants tested may inhibit nematode growth and development and hence warrant in vivo tests would support their ethnomedicinal application.