Abstract
Fifty-five organic and aqueous extracts of 11 plants used in malaria therapy in Kisii District, Kenya were tested in vitro against chloroquine (CQ)-sensitive and resistant strains of Plasmodium falciparum . Of the plants tested, 73% were active (IC50B/100 mg/ml). Three plants, Vernonia lasiopus , Rhamnus prinoides and Ficus sur afforded extracts with IC50 values ranging less than 30 mg/ml against both CQ-sensitive and resistant strains. Combination of some extracts with CQ against the multi-drug resistant P. falciparum isolate V1/S revealed some synergistic effect. The plant extracts with low IC50 values may be used as sources for novel antimalarial compounds to be used alone or in combination with CQ. 2002 Elsevier Science Ireland Ltd. All rights reserved.