The antiplasmodial, anti-trypanosomal and anti-leishmanial activity of 25 plant extracts
obtained from seven Tanzanian medicinal plants:
Annickia (Enantia) kummeriae (Annonaceae),
Artemisia annua
(Asteraceae),
Pseudospondias microcarpa
(Anacardiaceae),
Drypetes natalensis
(Euphorbiaceae),
Acridocarpus chloropterus
(Malpighiaceae),
Maytenus senegalensis
(Celastraceae)
and
Neurautanenia mitis
(Papilonaceae), were evaluated in vitro against
Plasmodium falciparum
K1,
Trypanosoma brucei rhodesiense
STIB 900 and axenic
Leishmania donovani
MHOM-ET-67/82. Out of the
25 extracts tested, 17 showed good antiplasmodial activity (IC
50 0.04-5.0 μg/ml), 7 exhibited moderate
anti-trypanosomal activity (IC
50 2.3- 2.8 μg/ml), while 5 displayed mild anti-leishmanial activity
(IC50 8.8-9.79 μg/ml).
A. kummeriae, A. annua, P. microcarpa, D. natalensis, M. senegalensis and
N. mitis
extracts had good antiplasmodial activity (IC
50 0.04-2.1 μg/ml) and selectivity indices (29.2-2,250
μg/ml). The high antiplasmodial, moderate anti-trypanosomal and mild anti-leishmanial activity
make these plants good candidates for bioassay-guided isolation of anti-protozoal compounds
which could serve as new lead structures for drug development.