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

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