Anti-malarial activities of haxane extracts of Senna occidentalis (coffee weed) leaves and Syzygium aromaticum (clove) flowers bud against Plasmodium falciparum

Abstract

Malaria is a major health concern in Subtropical Africa and treatment options is a great challenge. This study has screened the phytochemicals and determined in vitro anti-malarial activities and acute toxicity study of leaves of Senna occidentalis and flower buds of Syzygium aromaticum hexane extracts against Plasmodium falciparum using standard procedures. The results of phytochemical screening of the extracts have showed presence of alkaloids, flavonoids, saponins, tannins and anthraquinones in both selected plant materials while; steroids were only detected in S. occidentalis. The test for anti-malarial activity of S. occidentalis showed strong activity against P. falciparum at concentrations of 50, 25 and 12.5mg/ml with percentage growth inhibition and mean infected RBC count (SD) of 87.0 (1.3), 67.7 (3.3) and 50.0 (4.3) respectively, while S. aromaticum showed strong activity only at concentration of 50mg/ml with percentage growth inhibition and mean infected RBC count (SD) of 81.1(1.7). From the acute toxicity study, the results of phases I and II showed no mortality in any of the experimental groups of rats after 24hours and up to four weeks after oral administration of both extracts at concentrations ≤5000 mg/kg, no signs of delay toxicity were recorded. It can be concluded that, the most potent extract is S. occidentalis and oral administration of both extracts at doses ≤5000 mg/kg is experimentally safe.