In vitro Biochemical Evaluation of the Antiplasmodial Activities of various fractions obtained from Phyllanthus nivosus leaf extract
Resistance to anti malarial medicines has been a threat to global efforts toward malariaeradication and elimination. Highly effective anti malarial agents are necessary requirementsfor overcoming this challenge and this requires continuous efforts towards development of new drugs to replace the old ones as they lose effectiveness. Phyllanthus nivosus leaf extract has been shown in our previous study to possess antimalarial potential through its inhibition of Plasmodium Lactate Dehydrogenase (pLDH) activityin vitro. In this study, various fractions of the leaf extract were screened for antiplasmodial activity. Plasmodium falciparum infected erythrocytes were incubated at 370C in RPMI 1640 culture media (modified with L-glutamine, sodium bicarbonate and HEPES) in the presence of varying concentrations (12µg/ml, 6µg/ml and 3µg/ml) of ethanolic extract, hexane, ethyl acetate, butanol and alkaloid rich fractions of Phyllantus nivosus leaf. Same concentrations of Chloroquine and Artemether Lumefantrine (ACT) were used as standards. Plasmodium Lactate dehydrogenase activity was determined after 72 hours as a measure of parasite growth. pLDH activity was reduced in all cases with IC50 values of 1.74µg/ml, 1.76µg/ml, 1.53µg/ml,5.14µg/ml and 2.10µg/ml respectively, as compared with 2.09µg/ml and 2.18µg/ml for chloroquine and ACT respectively. All the fractions were found to contain either alkaloids or terpenes or both, except the butanol fraction which also displayed the least antiplasmodial activity. It is therefore suggested that the antimalarial activity of this plant may be attributed to the presence of alkaloids and terpenes.
Index Terms – Anti malarial, Plasmodium falciplarum, Plasmodium lactate dehydrogenase, Phyllanthus nivosus.