In vitro and in vivo assessement of the antimalarial activity of sergeolide.

The antimalarial activity of sergeolide (a quassinoid from PICROLEMMA PSEUDOCOFFEA) was investigated both, IN VITRO on PLASMODIUM FALCIPARUM cultures and IN VIVO through a classical test of schizontocidal action against PLASMODIUM BERGHEI in mice. Sergeolide showed a very strong antiplasmodial activity IN VITRO as well as IN VIVO. Low concentrations (0.006 microg/ml) were able to fully inhibit the IN VITRO growth of chloroquine-sensitive and resistant strains of P. FALCIPARUM. Small amounts (0.26 mg/kg/day) markedly reduced the virulence of experimentally induced P. BERGHEI infection in mice. However, sergeolide, because of its high toxicity (LD 50: 1.8 mg/kg), does not seem, in its present form to be useful for malaria curative treatment.