We show here that a crude extract of green tea as well as two of its main constituents, epigallocatechin-3-gallate (EGCG) and epicatechin gullate (ECG), strongly inhibit Plasmodium falciparum growth in vitro. Both these catechins are found to potentiate the antimalarial effects of artemisinin without interfering with the folate pathway. The importance of these findings and their mechanistic implications are discussed in view of future therapeutic strategies. (c) 2006 Elsevier Inc. All rights reserved.