Comparative Assessment of the Antiplasmodial Activity and Acute Toxicity of Schumanniophyton magnificum Good & Halle (Rubiaceae) Leaves, Trunk and Roots Methanolic Extracts

Abstract

Background: Despite the various medicinal applications of Schumanniophyton magnificum, no comparative data are available to determine the part with best antiplasmodial activity and to guarantee its safety. This work deals with the evaluation of the antiplasmodial activity of methanolic extracts of S. magnificum organs as well as the study of acute toxicity of the most active part.
 Materials and methods: The methanolic extracts of the leaves, stem bark, trunk wood, root wood and root bark, were obtained by maceration with 96% methanol. Phytochemical screening, based on precipitation and coloring reactions, to highlight the chemical groups present in the plant. The antiplasmodial test was ran against chloroquine sensitive Plasmodium falciparum 3D7 strains while the study of the in vivo acute toxicity was conducted according to guideline 423 of the OECD protocol at a fixed dose on Wistar rats.
 Results: Phytochemical screening of the methanol extracts of these plants organs revealed the presence of alkaloids, triterpenoids, saponins, anthraquinones, polyphenols, coumarins anthocyanins and flavonoids. The antiplasmodial activity showed that only the leaves exhibited a moderate antiplasmodial effect with IC50 of 30.77 µg/ml. An oral administration of the methanolic extract of the leaves did not induce an abnormal variation of the physiological parameters in female Wistar laboratory rats, at non-toxic doses of 50, 300 and 2000 mg/kg body weight for 14 days.
 Conclusion: The leaves of S. magnificum exhibited the best antimalarial activity and were non toxic, thus justifying the use of the plant in the treatment of malaria in traditional pharmacopoeia.
 Keywords: Phytochemical screening, Antiplasmodial activity, Acute toxicity, Schumanniophyton magnificum, Medicinal plant.