Antitrypanosomal and Cytotoxic Activities of Selected Medicinal Plants and Effect of Cordyline terminalis on Trypanosomal Nuclear and Kinetoplast Replication

Surra is a hemoprotozoal disease affecting domesticated and wildlife animals. Thecausative agent is the hemoprotozoan parasite Trypanosoma evansi. Only few drugsare currently available for the treatment of this disease that are old and encounterthe problem of resistance emergence, which punctuates the urgent demand for newdrugs for the treatment of surra. In the current study, the antitrypanosomal activityof the aqueous and ethanol extracts of five selected medicinal plants namelyAcanthus ilicifolius, Allium sativum, Cordyline terminalis, Goniothalamus tapis andMaesa ramentacea was evaluated in vitro against T. evansi strain Te7 and thecytotoxic activity of the extracts was evaluated on Vero cells using MTT-cellproliferation assay. The ethanol extract of leaves of G. tapis scored the most potent antitrypanosomal activity (IC50 of 7.61μg/ml) and a selectivity index (SI) of 11.47, while the aqueous extract of C. terminalis leaves exhibited an IC50 of 48.1 μg/ml and the highest SI of 27.21. Addition of 50 μg/ml of C. terminalis extract to T. evansi culture has led to a significant inhibition of nuclear and kinetoplast DNA replication, contributing to its in vitro antitrypanosomal activity. From the current study, it can be concluded that the aqueous extract of leaves of C. terminalis shows considerable antitrypanosomal activity and it could be a potential source of new antitrypanosomal compounds.