Anti-trypanosomal effects of Azadiracta indica (neem) extract on Trypanosoma brucei rhodesiense-infected mice

Abstract

An in vivo study was carried out to determine the anti-typanosomal effect of aqueous extracts of the bark of Azadiracta indica (neem) in Trypanosoma brucei rhodesiense-infected mice. The extracts were orally administered ad libitum twenty four hours post-infection for three days to mice after dose determination and toxicity testing. The effect of the extracts in trypanosome-infected mice was monitored for 20 days by determining changes in the packed cell volume (PCV), parasitemia levels and survival rate. The bark extracts of the neem plant did not show any acute toxicity to the uninfected animals because no significant effect on weight and PCV was recorded. However, infection with T. b. rhodesiense led to a decrease in weight and PCV, the decrease being more in those animals that were given water only and low doses of plant extracts. The extracts produced a dose-dependent effect at delaying onset of parasites appearance in circulation, decreasing level of parasitemia and PCV. Treatment with 1000 mg/kg of plant extract was comparable to and in some cases more effective than suramin, a known trypanocidal drug.