In vitro and in vivo activities of atalaphillinine and related acridone alkaloids against rodent malaria.

Thirty acridone alkaloids obtained from Citrus, Glycosmis, or Severinia plants (members of the family Rutaceae) were tested for their antimalarial activities in vitro and in vivo. At a concentration of 10 micrograms/ml in vitro, seven of these alkaloids suppressed 90% or more of Plasmodium yoelii, which causes malaria in rodents. Atalaphillinine, when injected intraperitoneally in a daily dose of 50 mg/kg for 3 days into mice infected with 10(7) erythrocytes parasitized with Plasmodium berghei or Plasmodium vinckei, completely suppressed the development of malaria parasites, with there being no obvious acute toxic effects from the tested dose.