In vitro and in vivo antimalarial and cytotoxic activity of five plants used in congolese traditional medicine.
OBJECTIVE
The in vitro antiplasmodial activity and cytotoxicity of methanolic and dichloromethane extracts from five Congolese plants were evaluated. The plants were selected following an ethnobotanical survey conducted in D.R. Congo and focusing on plants used traditionally to treat malaria. The in vivo antimalarial activity of aqueous and methanolic extracts active in vitro was also determined in mice infected by Plasmodium berghei berghei.


METHODS
The growth inhibition of Plasmodium falciparum strains was evaluated using the measurement of lactate dehydrogenase activity. The extracts (aqueous, CH(3)OH, EtOH and CH(2)Cl(2)) were prepared by maceration and tested in vitro against the 3D7 (chloroquine sensitive) and W2 (chloroquine resistant) strains of Plasmodium falciparum and against the human normal fetal lung fibroblasts WI-38 to determine the selectivity index. Some extracts were also used at the dose of 300 mg/kg to evaluate their activity in mice infected since 4 days by Plasmodium berghei.


RESULTS
Two plants presented a very high activity (IC(50)<3 microg/ml). These plants were Strychnos icaja roots bark (MeOH and CH(2)Cl(2)) and Physalis angulata leaves (MeOH and CH(2)Cl(2)). One plant (Anisopappus chinensis whole plant, MeOH and CH(2)Cl(2)) presented a high activity (IC50<15 microg/ml). The extracts of Anisopappus chinensis and Physalis angulata showed also a good inhibition of parasitemia in vivo. Flavonoids, phenolic acids and terpenes were identified in these plants by a general phytochemical screening method.


CONCLUSIONS
Three plants showed a very interesting antiplasmodial activity (Anisopappus chinensis, Physalis angulata and Strychnos icaja) and one of them showed a good selectivity index (>10, Anisopappus chinensis). Anisopappus chinensis and Physalis angulata were also active in vivo.
Lusakibanza
M
M
University of Kinshasa, Faculty of Pharmaceuticals Sciences, Kinshasa XI, Democratic Republic of Congo.
Mesia
G
G
Tona
G
G
Karemere
S
S
Lukuka
A
A
Tits
M
M
Angenot
L
L
Frédérich
M
M
D000818:Animals; D000962:Antimalarials / Q000009:adverse effects / Q000302:isolation & purification / Q000494:pharmacology*; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D015023:Democratic Republic of the Congo; D004195:Disease Models, Animal; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D008288:Malaria / Q000188:drug therapy* / Q000382:microbiology; D016488:Medicine, African Traditional; D051379:Mice; D008815:Mice, Inbred Strains; D010936:Plant Extracts / Q000009:adverse effects / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D010962:Plasmodium berghei / Q000187:drug effects / Q000472:pathogenicity; D010963:Plasmodium falciparum / Q000187:drug effects
D000962:Antimalarials; D010936:Plant Extracts