title: In vitro sensitivity of Plasmodium falciparum field isolates to extracts from Cameroonian Annonaceae plants.
abstract: In a search for new plant-derived antimalarial extracts, 19 fractions were obtained from three Annonaceae species, Uvariopsis congolana (leaf, stem), Polyalthia oliveri (stem bark), and Enantia chlorantha (stem, stem bark) with yields ranging from 0.33% to 4.60%. The extracts were prepared from 500 g of each plant part, using organic solvents to afford five methanolic fractions (acetogenin rich), five water fractions, five hexane fractions, and four interface precipitates. Evaluation of the activity of fractions in vitro against field isolates of the malaria parasite Plasmodium falciparum showed that acetogenin-rich fractions and interface precipitates were the most potent, with IC(50) values ranging from 0.05 to 8.09 μg/ml. Sensitivity of parasite isolates to plant extracts varied greatly, with over 100-fold difference from isolate to isolate in some cases. The active acetogenin-rich fractions and interface precipitates were assessed in combination with chloroquine in the same conditions, and showed additive interaction in the huge majority of cases. Synergistic interactions were found in some cases with acetogenin-rich fractions. Acute toxicity of promising fractions was evaluated through oral administration in Swiss albino mice. Tested fractions appeared to be safe, with LD(50) values higher than 2 g/kg. In summary, acetogenin-rich fractions from Annonaceae species showed high potency against P. falciparum field isolates and safety by oral administration in mice, supporting their detailed investigation for antimalarial drug discovery.
authors: Laboratory of Phytobiochemistry and Medicinal Plants Study, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon.
authors: Eugénie Aimée Madiesse
authors: EA
authors: Kemgne
authors: Wilfred Fon
authors: WF
authors: Mbacham
authors: Fabrice Fekam
authors: FF
authors: Boyom
authors: Paul Henri Amvam
authors: PH
authors: Zollo
authors: Etienne
authors: E
authors: Tsamo
authors: Philip J
authors: PJ
authors: Rosenthal
mesh_terms: D000818:Animals; D029061:Annonaceae / Q000737:chemistry*; D000962:Antimalarials / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D002163:Cameroon; D002738:Chloroquine / Q000494:pharmacology; D004347:Drug Interactions; D064420:Drug-Related Side Effects and Adverse Reactions; D020128:Inhibitory Concentration 50; D007928:Lethal Dose 50; D051379:Mice; D021261:Parasitic Sensitivity Tests; D010936:Plant Extracts / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D010963:Plasmodium falciparum / Q000187:drug effects*; D016019:Survival Analysis
chemical_list: D000962:Antimalarials; D010936:Plant Extracts; D002738:Chloroquine