Antimalarial chemotherapy with natural products and chemically defined molecules.

In the present work we have described the in vivo antimalarial activity of six different plants. Two of them (Vernonia brasiliana and Eupatorium squalidum) were tested in a randomic approach among 273 crude extracts from plants; four (Acanthospermum australe, Esenbeckia febrifuga, Lisianthus speciosus and Tachia guianensis) were selected after screening 22 crude extracts from different medicinal plants used in Brazil against fever and/or malaria. We also studied chemically defined molecules and some of them showed antimalarial activity in vitro. Some aspects of recent research with natural products aiming to produce drugs are discussed.