Antiplasmodial potential of selected medicinal plants from eastern Ghats of South India.

Malaria caused by the protozoan parasite Plasmodium falciparum, is a major health problem of the developing world. In the present study medicinal plants from Eastern Ghats of South India have been extracted with ethyl acetate and assayed for growth inhibition of asexual erythrocytic stages of chloroquine (CQ)-sensitive (3D7) and (CQ)-resistant (INDO) strains of P. falciparum in culture using the fluorescence-based SYBR Green I assay. Studied extracts showed a spectrum of antiplasmodial activities ranging from (a) very good (IC(50)<10-10 μg/mL: Cyperus rotundus and Zingiber officinale); (b) good (IC(50), >10-15 μg/mL: Ficus religiosa and Murraya koenigii); (c) moderate (IC(50)>15-25 μg/mL: Ficus benghalensis); (d) poor activity (IC(50)>25-60 μg/mL) and (e) inactive (IC(50)>60 μg/mL). Resistance indices ranging from 0.78 to 1.28 suggest that some of these extracts had equal promise against the CQ resistant INDO strain of P. falciparum. Cytotoxicity assessment of the extracts against HeLa cell line using MTT assay revealed that the selectivity indices in the range of 3-15 suggesting a good margin of safety.