Antimalarial efficacy and toxicity evaluation of 80% ethanol extracts from the stem bark of <i>Enantia olivacea, Garcinia punctata</i> and <i>Massularia acuminata</i>

Abstract

The aim of this study was to evaluate the antimalarial efficacy and the acute toxicity of the 80% ethanol extracts of Enantia olivacea, Garcinia punctata and Massularia acuminata stem barks. The in vivo antimalarial efficacy of these extracts was investigated alone or in combination by the 4-day suppressive test. To assess the acute toxicity, mice were treated with a single oral dose of each individual (2,000 mg/kg) and combined extract (≤ 1,200 mg/kg). During 7 days, the animals were observed for any clinical signs of toxicity, changes in body weight and mortality. At 200 mg/kg, Enantia olivacea, Garcinia punctata and Massularia acuminata extracts resulted, respectively, in 57.2 %, 45.3 % and 32.6 % reduction of parasitemia in mice. The combination therapy of Enantia olivacea, Garcinia punctata and Massularia acuminata (50 and 200 mg/kg of each extract) showed increased protection and survival rate associated with a significant delay of recrudescence compared with each monotherapy. No acute toxicity was observed in all the treated mice, and the 50 % lethal dose of the combined extract was assumed to be > 1,200 mg/kg. These results can partly support the use of these three plant parts for the treatment of uncomplicated malaria in Congolese traditional medicine. Keywords : Congolese medicinal plants, combination therapy, Plasmodium berghei , hemolysis assay, acute toxicity