In vitro antiplasmodial activity and toxicity assessment of some plants from Nigerian ethnomedicine.
BACKGROUND
The emergence and spread of Plasmodium falciparum-resistant parasites to nearly all available antimalarial drugs pose a threat to malaria control and necessitates the need to continue the search for new effective and affordable drugs. Ethnomedicine has been shown to be a potential source of antimalarial compounds or source of template for the synthesis of novel antimalarial molecules.


OBJECTIVE
The antiplasmodial activity and toxicity assessment of 30 plant extracts from eight medicinal plants identified in Nigerian ethnomedicine for the treatment of febrile illnesses were evaluated.


METHODS
In vitro antimalarial activity was evaluated using Plasmodium falciparum NF54 (sensitive to all antimalarial drugs) and K1 (chloroquine/pyrimethamine resistant) strains in the [(3)H]-hypoxanthine incorporation assay. Toxicity was determined against mammalian L6 cells using Alamar blue assay.


RESULTS
The ethyl acetate extract of leaves of Ocimum gratissimum Linn. (Labiatae) and hexane extract of stem bark of Trema orientalis (L.) Blume (Ulmaceae) showed the highest antiplasmodial activity (IC(50) 1.8-1.93 µg/mL) against P. falciparum K1 strain but elicited low cytotoxicity (selective index >10). However, hexane, ethyl acetate or methanol extracts of leaves of Terminalia catappa Linn. (Combretaceae), Jatropha curcas Linn. (Euphorbiaceae), Vitex doniana Sweet. (Verbenaceae) and stem bark of Vitex doniana displayed antiplasmodial activity (IC(50) 2.3-16.9 µg/mL) with good selectivity (21-120) for malaria parasites.


CONCLUSIONS
The antiplasmodial activity of Terminalia catappa and Vitex doniana against P. falciparum K1 is being reported for the first time in Nigerian ethnomedicine and these plants could be potential source of antimalarial agents.
Abiodun
Oyindamola
O
Department of Pharmacology and Therapeutics, College of Health Sciences, Ladoke Akintola University of Technology, Oshogbo, Nigeria. oyinoduola@yahoo.co.uk
Gbotosho
Grace
G
Ajaiyeoba
Edith
E
Happi
Tientcha
T
Falade
Mofolusho
M
Wittlin
Sergio
S
Sowunmi
Akintunde
A
Brun
Reto
R
Oduola
Ayoade
A
D000818:Animals; D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D002478:Cells, Cultured; D020834:Ethnopharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D016488:Medicine, African Traditional; D032448:Myoblasts, Skeletal / Q000187:drug effects / Q000378:metabolism; D009549:Nigeria; D008517:Phytotherapy / Q000379:methods; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D010946:Plants, Medicinal / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects*; D051381:Rats; D018675:Toxicity Tests
D000962:Antimalarials; D010936:Plant Extracts