Antiplasmodial activity of selected Sudanese medicinal plants with emphasis on Maytenus senegalensis (Lam.) Exell

The antiplasmodial activity of plant extracts related to four families was tested on chloroquine sensitive strain 3D7 and chloroquine resistant strain Dd2 of Plasmodium falciparum. The methanolic extract of Harrisonia abyssinica (Simaroubaceae) inhibited Dd2 with IC 50 value of 4.7 μ g/ml, while in 3D7, the IC 50 value was 10 μ g/ml. Most of the plants from the family Meliaceae showed highly potent antiplasmodial activity against the two tested strains. Khaya senegalensis, Azadirachta indica and Trichilia emetica showed IC 50 values less than 5 μ g/ml. The methanolic extract of Annona squamosa (Annonaceae) leaves showed high antiplasmodial activity with IC 50 values of 2 and 30 μ g/ml on 3D7 and Dd2, respectively. While stem bark showed moderate activity with IC 50 values of 8.5 and 120 μ g/ml on Dd2. Maytenus senegalensis ( Celastraceae ) possessed IC 50 values of 3.9 on 3D7, 10 μ g/ml on Dd2 and had no effect on lymphocyte proliferation even at the highest tested concentration; the IC 50 was greater than 100 μ g/ml. Liquid-liquid separation of the methanolic extract of M. senegalensis revealed that the dichloromethane extract possessed an IC 50 value of only 2.1 μ g/ml. Column fractionation of dichloromethane extract gave four fractions and fraction two showed an IC 50 value of 0.5 μ g/ml. Preliminary phytochemical analysis of dichloromethane fraction revealed terpenoids and traces of phenolic principles but no alkaloid, tannins or flavonoids were detected.