THE EFFECTS OF BISTRATENE-A ON THE DEVELOPMENT OF PLASMODIUM-FALCIPARUM IN CULTURE

The effects of the marine ascidian compound bistratene A on in vitro c ultures of Plasmodium falciparum were assessed. Concentrations from 0 to 1.5 mu g ml(-1) of the compound were tested. The parasitaemia in as ynchronous cultures treated with bistratene A increased normally over the first 40 h, then decreased leaving only gametocytes. When synchron ized cultures were treated with a constant dose of 50 ng ml(-1), gamet ocytes developed more rapidly than they did in control cultures. In ad dition, gametocytes developed in drug-treated cultures of P. falciparu m that normally do not produce gametocytes. Bistratene A appears to in hibit merozoite invasion as well as to induce gametocytogenesis.