Tanzanian medicinal plants used traditionally for the treatment of malaria: <i>In vivo</i> antimalarial and <i>in vitro</i> cytotoxic activities

Abstract

Abstract Seventeen fractions of extracts obtained from 11 Tanzanian medicinal plants, which had previously been shown to possess a high antimalarial activity in vitro were submitted to the 4‐day suppressive test in Plasmodium berghei ‐infected mice, and were investigated for cytotoxic activity in human carcinoma cell lines in vitro. Several fractions administered orally to the mice (500 mg/kg body weight/day) produced a significant reduction of parasitaemia. The most effective plant fractions investigated were those of the root and stem bark of Maytenus senegalensis (90% and 63% suppression of parasitaemia, respectively) and of the roots of Cissampelos mucronata (59% suppression). Highest cytotoxic activities were found with all fractions of Maytenus senegalensis (IC 50 1 μg/mL) and with the PE fraction of the roots of Salacia madagascariensis (median IC 50 =1.2 μg/mL for HT 29 and 2.3 μg/mL for KB).