Use of the Trypanosomid Flagellate, Crithidia fasciculata, for Evaluating Antimalarials.

Abstract

Crithidia fasciculata is competitively inhibited by several 2,4-diaminopyrimidine antagonists of folic and folinic acids. These in vitro inhibition patterns obtained in a chemically defined medium parallel the order of relative drug activities obtained by others on animals infected with any of several spp. of plasmodia. Poor correspondence exists between bacterial inhibitions in vitro and inhibitions of plasmodia in vivo by these pyrimidines. The results suggest that this flagellate may be preferable to bacteria hitherto used for preliminary in vitro evaluation of antimalarials.