INHIBITION OF THE GROWTH AND DEVELOPMENT OF ASEXUAL AND SEXUAL STAGESOF DRUG-SENSITIVE AND RESISTANT STRAINS OF THE HUMAN MALARIA PARASITEPLASMODIUM-FALCIPARUM BY NEEM (AZADIRACHTA-INDICA) FRACTIONS

Neem (Azadirachta indica) has been shown to possess anti-malarial acti vity. In this study we systematically evaluated extracts of neem seeds and purified fractions further enriched in polar or non-polar constit uents for their effect on in vitro growth and development of asexual a nd sexual stages of the human malaria parasite Plasmodium falciparum. Use of synchronized stages of parasites suggested trophozoites/schizon ts as the susceptible target stages to various neem extracts. In addit ion, all the maturation stages of gametocytes were also killed by vari ous neem fractions tested. The anti-plasmodial effect of neem componen ts was also observed on parasites previously shown to be resistant to other anti-malarial drugs, i.e. chloroquine and pyrimethamine suggesti ng a different mode of action. Neem seed fractions are thus active not only against the parasite stages that cause the clinical infection bu t also against the stages responsible for continued malaria transmissi on. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.