Anti-trypanosomal effects of aqueous extract of Ocimum gratissimum (Lamiaceae) leaf in rats infected with Trypanosoma brucei brucei.

The anti-trypanosomal effects of aqueous extract of the leaf of Ocimum gratissimum were evaluated in both in-vitro and in-vivo studies. The anti-trypanosomal activity of the extract against Trypanosoma brucei was investigated in-vitro. The survival and motility of the trypanosomes were completely inhibited within two hours of incubation in various concentrations of the extract. Parasite survival time was concentration dependent being longer in lower (25 and 12.5 mg/ml) than higher (100, 75 and 50 mg/ml) concentrations of the extract. The in-vivo anti-trypanosomal effect of the leaf extract of the leaf extract was investigated in rats infected with Trypanosoma brucei and treated with the extract. The infected rats treated with the extract had less dramatic clinical manifestations and mortality, survived longer and higher PCV values than their untreated counterparts, however, parasitaemia was not significantly reduced. The results suggest that the folkloric medicinal application of the aqueous extract of Ocimum gratissimum has no possible pharmacological basis.