Antiplasmodial activity of selected sudanese medicinal plants with emphasis on Acacia nilotica

Twenty-two plant organs from eleven plants comprising five families were ex tracted and screened for antiplasmodial activity in vitro against Plasmodiu m falciparum 3D7 (chloroquine sensitive) and Dd2 (chloroquine resistant and pyrimethamine sensitive). Fifty nine percent of plant extracts from 22 ext racts exerted activity on P. falciparum strain 3D7 with an IC50 less than 5 0 mu g/mL, whereas 43% of plant extracts showed an IC50 value within 50 mu g/mL on Dd2 strains. Plant extracts from Gardenia lutea, Haplophyllum tuber culatum, Cassia tora, Acacia nilotica and Aristolochia bracteolata possesse d IC50 values less than 5 mu g/mL on both tested strains, Bioassay guided f ractionation of A. nilotica revealed that the ethyl acetate extract possess ed the highest activity (IC50 = 1.5 mu g/mL). Fraction 2 (R-f = 0.75) prepa red by preparative chromatography showed the highest activity on P, falcipa rum (IC50 = 1.7 mu g/mL). Phytochemical analysis indicated that the most ac tive phase contained terpenoids and tannins and was devoid of alkaloids and saponins, The effect of plant extracts on lymphocyte proliferation showed low toxicity to the hunan cells. This plant has been subjected to long term clinical trials in folk medicine and is a promising plant, Copyright (C) 1 999 John Wiley & Sons, Ltd.