Effects of Aqueous Extracts of Cymbopogon citratus in Malaria

Abstract

The anti-malarial effect of an aqueous extract of Cymbopogon citratus, a Nigerian traditional medicinal plant, has been investigated in mice infected with plasmodium yoelii nigeriensis. The plant extract was found effective in suppressing malarial infection. Infected animals, orally given in drinking water 0.106 – 0.473 g ml^-1 of the extract for 5 consecutive days after the disease had been established, were observed to be cleared of the malarial parasites 4 days after commencement of treatment. The mice, however, lived thereafter, for another 8-10 days before dying because only a low number of non-parasitized red-blood cells were left in the circulation. When on the other hand, the crude salt was injected i. p in doses of 1.0-1.5 g kg^-1 for 3 consecutive days, it suppressed the infection during and 2 days after the extract treatment, at which time it was observed that the erythrocyte infection rate (EIR) started rising until the animals died at about 8 days post-treatment, that is, they survived 5-6 days longer than the non-treated (control animals). Chemoprophylactic action of the extract injected i. p prior to infection gave protection for about 72 hours. No adverse reactions were recorded when the drug plant was given orally, but certain reactions were noted when administered i. p to which they survived. The drug plant given i. p has an LD₅₀ of 2.32 g kg^-1 and the plant is schizontocidal in action. Chemical analysis of the extract revealed presence of alkaloids, saponins, tannins and simple sugars.