title: Antiprotozoal screening and cytotoxicity of extracts and fractions from the leaves, stem bark and root bark of Alstonia congensis.
abstract: BACKGROUND
  To evaluate the antiprotozoal activity and cytotoxicity of extracts and fractions from the leaves, root bark and stem bark of Alstonia congensis (Apocynaceae), used in traditional medicine against parasitic diseases.
  
  
  METHODS
  The aqueous and 80% MeOH extracts, and a series of fractions and subfractions from the leaves, stem and root bark of Alstonia congensis were tested in vitro for their antiprotozoal activity against Trypanosoma brucei brucei, Trypanosoma cruzi, Lesihamania infantum and the chloroquine and pyrimethamine-resistant K1 strain of Plasmodium falciparum. Their cytotoxicity on MRC-5 cells (human lung fibroblasts) was evaluated as well.
  
  
  RESULTS
  The aqueous and 80% MeOH extracts and a series of subfractions of each plant part exhibited pronounced antiprotozoal activity against the K1 strain of Plasmodium falciparum with IC50 values ranging from 2 to 5 µg/ml, and good activity against Trypanosoma brucei brucei and Trypanosoma cruzi with IC50 values ranging between 5 and 10 µg/ml. The residual 80% MeOH extract from the leaves, and the total alkaloid extract from stem and root bark were the only subfractions active against Leishmania infantum with IC50 values <10 µg/ml. None of the samples from the root bark was cytotoxic against MRC-cell lines (CC50>64 µg/ml). In general, the aqueous extract (traditional decoction) showed the highest selectivity, especially against Plasmodium falciparum.
  
  
  CONCLUSIONS
  These results can partly support and justify the traditional use of these plant parts of Alstonina congensis as raw materials for the preparation of traditional remedies to treat parasitic diseases such as malaria and trypanosomiasis.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Kinshasa, PO Box 212, Kinshasa XI, Congo.
authors.forename: S L
authors.initials: SL
authors.lastname: Lumpu
authors.forename: C M
authors.initials: CM
authors.lastname: Kikueta
authors.forename: M E
authors.initials: ME
authors.lastname: Tshodi
authors.forename: A P
authors.initials: AP
authors.lastname: Mbenza
authors.forename: O K
authors.initials: OK
authors.lastname: Kambu
authors.forename: B M
authors.initials: BM
authors.lastname: Mbamu
authors.forename: P
authors.initials: P
authors.lastname: Cos
authors.forename: L
authors.initials: L
authors.lastname: Maes
authors.forename: S
authors.initials: S
authors.lastname: Apers
authors.forename: L
authors.initials: L
authors.lastname: Pieters
authors.forename: R K
authors.initials: RK
authors.lastname: Cimanga
mesh_terms: D031051:Alstonia / Q000737:chemistry*; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D020834:Ethnopharmacology / Q000379:methods; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D018314:Leishmania infantum / Q000187:drug effects; D008168:Lung / Q000187:drug effects; D021261:Parasitic Sensitivity Tests / Q000379:methods; D008517:Phytotherapy / Q000379:methods; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010963:Plasmodium falciparum / Q000187:drug effects; D014346:Trypanosoma brucei brucei / Q000187:drug effects; D014349:Trypanosoma cruzi / Q000187:drug effects
chemical_list: D000981:Antiprotozoal Agents; D010936:Plant Extracts