In vitro antiplasmodial activity and cytotoxicity of nine plants traditionally used in Gabon.
OBJECTIVE
As part of a project to identify new compounds active on malarial parasites, we tested the in vitro antiplasmodial activity of nine plants traditionally used to treat malaria symptoms in Haut-Ogooué Province, South-East Gabon.


METHODS
Dichloromethane and methanolic extracts of each plant were tested for their antiplasmodial activity on two chloroquine-resistant strains of Plasmodium falciparum (FCB and W2), based on lactate dehydrogenase activity. Cytotoxicity was assessed with the MTT test on MRC-5 human diploid embryonic lung cells.


RESULTS
The methanolic extract of Staudtia gabonensis and the dichloromethane extract of Adhatoda latibracteata showed high antiplasmodial activity (IC₅₀<1 μg/ml) and low cytotoxicity, with selectivity indexes of about 58.25 and 16.43, respectively. The methanolic extract of Monodora myristica and the dichloromethane extract of Afromomum giganteum also showed promising activity (1<IC₅₀<10 μg/ml) and low cytotoxicity, with selectivity indexes about 15.70 and 12.48, respectively. Dichloromethane extracts of Monodora myristica and Leonotis Africana showed moderate activity (10<IC₅₀<40 μg/ml), with selectivity indexes about 6.07 and 28.89, respectively. Both extracts of Culcasia lancifolia had IC₅₀ values of 10-40 μg/ml but high cytotoxicity (selectivity indexes <2.77). The methanolic extract of Dorstenia klaineana had moderate antiplasmodial activity (IC₅₀ around 17 μg/ml) but strong cytotoxicity (0.43 μg/ml), giving a selectivity index of about 0.03.


CONCLUSIONS
Most extracts of nine selected plants traditionally used to treat malaria in Gabon had interesting antiplasmodial activity in vitro. This supports continued investigations of traditional medicines in the search for new antimalarial agents. The compounds responsible for the observed antiplasmodial effects are under investigation.
Unité de Parasitologie Médicale, Centre International de Recherches Médicales de Franceville, B.P. 769, Franceville, Gabon. Lekana jb@yahoo.fr
Jean Bernard
JB
Lekana-Douki
Jean Bernard
JB
Bongui
Sandrine Lydie
SL
Oyegue Liabagui
Sonya Estelle
SE
Zang Edou
Rafika
R
Zatra
Ulrich
U
Bisvigou
Pierre
P
Druilhe
Jacques
J
Lebibi
Fousseyni Samba
FS
Toure Ndouo
Maryvonne
M
Kombila
D002470:Cell Survival / Q000187:drug effects*; D005681:Gabon; D006801:Humans; D008288:Malaria / Q000188:drug therapy*; D016488:Medicine, African Traditional; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D010946:Plants, Medicinal / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects; D013045:Species Specificity
D010936:Plant Extracts