Schizontocidal effects of oral artesunate on Plasmodium berghei in mice and P knowlesi in monkeys.

AIM: To study the blood schizontocidal effect of oral artesunate on P berghei in mice and P knowlesi in monkey. METHODS: Effects of artesunate and chloroquine were detected with "4-day test" and "28-day test" on P berghei in mice and "7-day test" on P knowlesi in Macaca mudatta. RESULTS: The suppressive efficacy of oral artesunate was inferior to chloroquine on P berghei K173 strain but the time for 50% and 90% reduction and the time of clearance of parasitemia was 10-15 h shorter than that of chloroquine. Its curative effect on RC/K173 line was markedly superior to that of chloroquine. Moreover, artesunate showed no cross-resistance with chloroquine, index of resistance I90 was only 1.4. At 31.6, 10.0, and 3.16 mg.kg-1, artesunate and chloroquine oral administrations cured P knowlesi in all monkeys. Recrudescence did not occur in 105 d. CONCLUSION: The study of effects of oral artesunate in P berghei/mice and P knowlesi/Macaca mulatta model provided a useful index for clinical trial.