In vivo Antimalarial Activities of Five Ugandan Medicinal Plants on Plasmodium berghei in Mice

Aim: Medicinal plants have played an important role in the treatment of different ailments including malaria in developing countries particularly in Africa. This study has evaluated the antimalarial activities of Azadirachta indica A. Juss (Meliaceae), Cymbopogon citratus Stapf. (Poaceae), Moringa oleifera Lam. (Moringaceae), Tithonia diversifolia (Hemsl) A. Grey (Asteraceae) and Vernonia amygdalina Del. (Asteraceae) which are commonly-used for malaria treatment in Uganda.

Study Design: This is an experimental laboratory report on antimalarial activities of some Ugandan medicinal plants for subsequent profiling in an herbal pharmacopoeia and eventual drug development.

Place and Duration of Study: The Animal Research Facility and the Clinical and Research Laboratory, Faculty of Medicine, Mbarara University of Science and Technology, Uganda, between July 2019 and March 2020.

Methodology: The antimalarial activity of the hot infusion of each leaf was evaluated on chloroquine-sensitive Plasmodium berghei ANKA-infected mice using 4-day test at 100 – 400 mg/kg with chloroquine (10 mg/kg) and artemether-lumefantrine (4 mg/kg) as positive controls; and distilled water as negative control. The observed haematological responses of the animals were determined with an automated haematometer.

Results: The results showed dose-dependent activities in the animals treated with the extract of each plant leaf in varying degrees. Thus, V. amygdalina and T. diversifolia showed the highest antimalarial activities with the chemosuppression values of 75% and 66% at 400 mg/kg, respectively. The results of V. amygdalina, T. diversifolia and M. oleifera, extracts gave the lowest ED50 of 141, 195 and 231 mg/kg, respectively being significantly different from A. indica (ED50 319 mg/kg) and C. citratus (ED50 346 mg/kg) with V. amygdalina as the most potent extract among the five plant leaves.

Conclusion: The observed activities of the five plants have therefore supported their folkloric uses as antimalarial remedies by the Ugandan traditional medicine practitioners with obvious potentials for drug development.