In vivo trypanocidal activity of Nymphaea lotus Linn. methanol extract against Trypanosoma brucei brucei

ObjectiveTo evaluate the antitrypanosomal potentials of methanol extract of Nymphaea lotus Linn. (N. lotus) with the aim of obtaining a new lead for formulating safe, inexpensive, non-toxic and readily available trypanocidal drugs.MethodsSeventy percent (v/v) (methanol/water) crude extract of N. lotus was evaluated for antitrypanosomal activity in experimental trypanosomiasis using Trypanosoma brucei brucei-infected mice. Infected mice in different groups were administered intraperitoneally 100, 200, 300 and 400 mg/kg body weight/day of the crude for two weeks, while a positive control group was treated with standard drug, berenil.ResultsThe crude extract at a dose of 100 mg/kg body weight/day was more effective than the higher doses in completely clearing parasites from the blood of mice infected with Trypanosoma brucei brucei. Pre-treatment of healthy mice with the crude extract for 5 days before infection did not prevent the establishment of the infection, indicating that the extract had no prophylactic activity. Subinoculation of the blood and cerebrospinal fluid drawn from the cured mice into healthy mice failed to produce any infection within 50 days post inoculation. Administration of 1 000 mg/kg body weight of the crude extract led to the death of 50% of the experimental animals indicating a high level of toxicity of the extract at higher doses.ConclusionsThis study has demonstrated the potency of the crude extract of N. lotus in treating experimental trypanosomiasis at lower doses.