Comparative study on schizontocidal activity of recrystallized or crude daphnetin against malaria parasites.

Objective: To compare the schizontocidal activity of recrystallized or crude daphnetin against malaria parasites in vivo.
Methods: Schizontocidal activity of recrystallized or crude daphnetin at various dosages was assessed in mice infected with Plasmodium berghei ANKA using a "4-day suppress assay".
Results: The comparison of the reduction rate of parasitemia caused by either recrystallized or crude dephnetin showed that ED(50) of crude daphnetin was 18.36 mg/kg, with 95% confidence limit of 5.96-56.54 mg/kg while ED50 of recrystallized daphnetin was 11.46 mg/kg, with 95% confidence limit of 8.63-15.22 mg/kg.
Conclusion: The results indicate that the efficacy of recrystallized daphnetin is 37.6% higher than that of crude daphnetin.