Effects of Morinda lucida leaf extract on Trypanosoma brucei brucei infection in mice

The dried leaves of Morinda lucida were extracted with 50% methanol and the extract was recovered in a 9.7% w/w yield. Acute toxicity tests were performed in mice and the intraperitoneal LD50 of the extract was 2000 mg/kg. The extract induced purgation in mice from the first hour after oral administration and reached its peak between the third and fourth hour. The purgation was not dose-dependent. M. lucida leaf extract i.p. significantly suppressed the level of parasitemia after Trypanosoma brucei infection in mice. Suppression of existing parasitemia appeared dose-dependent with 1000 mg/kg i.p. producing the maximum effect. The best trypanocidal activity was obtained when treatment with M. lucida extract commenced simultaneously with trypanosome inoculation.