In vivo antimalarial activities of Enantia polycarpa stem bark against Plasmodium berghei berghei in mice

Abstract Ethnopharmacological relevance Enantia polycarpa (PC) Engl. Et Diels (Annonaceae) is used in traditional medicine as an antimalarial remedy in Southern Nigeria. Aim of the study The antimalarial activities of ethanolic stem bark extracts of Enantia polycarpa was studied in vivo, in mice infected with Plasmodium berghei berghei . Materials and methods The ethanolic stem bark extract of Enantia polycarpa was administered at doses ranging from 200 to 600 mg/kg/day to Plasmodium berghei infected mice in both early and established models of antiplasmodial studies. Results The extract of Enantia polycarpa exhibited promising antimalarial activity against both early and established infections. At a dose of 600 mg/kg the extract achieved a 75.8% and 72% chemosuppression of parasitaemia in the study of acute and established infections, respectively. The extract also prolonged mean survival time of Plasmodium berghei infected mice during the study of established infection. The mean survival time of mice administered Enantia polycarpa extract at 600 mg/kg/day (27 days) was significantly longer than infected/untreated control (12 days). For the acute toxicity study the extract had an intraperitoneal LD 50 of 186 mg/kg but caused no mortality when administered orally at doses as high as 2,000 and 4,000 mg/kg. Conclusions Collectively, the results indicate that Enantia polycarpa is safe when administered orally and possesses promising antimalarial activity, thus supporting its use in traditional medicine for the treatment of malaria.