title: In vitro antiprotozoal activity and cytotoxicity of extracts and fractions from the leaves, root bark and stem bark of Isolona hexaloba.
abstract: BACKGROUND
  Isolona hexaloba (Pierre) Engl. and Diels (Annonaceae) is traditionally used in D.R. Congo against parasitic diseases including malaria.
  
  
  METHODS
  Two crude aqueous extracts, 3 crude methanol extracts and 3 crude 80% ethanol extracts from the leaves, root bark and stem bark together with 12 subfractions from the crude 80% ethanol extracts were evaluated in vitro for their antiprotozoal activity against Trypanosoma brucei brucei, T. cruzi, Leishmania infantum and the chloroquine and pyrimethamine resistant K1 strain of Plasmodium falciparum. Their cytotoxic effects against MRC-5 cell lines were also assessed.
  
  
  RESULTS
  Results indicated that the most pronounced activities against T. b. brucei were recorded for the crude methanol extracts of root bark (IC50=1.97 µg/ml; SI>32.49) and leaves (IC50=2.65 µg/ml; SI>24.15). Three samples displayed good activity against T. cruzi: the 80% methanol extract of leaves (IC50=8.33 µg/ml; SI>3.92), its petroleum ether fraction (IC50=8.50 µg/ml; SI=2.52) and the crude aqueous extract of the stem bark (IC50=9.31 µg/ml; SI=3.46). The crude aqueous extract of the leaves exhibited a pronounced and selective activity against L. infantum (IC50=2.00 µg/ml; SI>32). The crude methanol extract of leaves (IC50=6.35 µg/ml; SI>10.10) and the 2 dichloromethane soluble fractions of the 80% ethanol extracts from root bark (IC50=6.96 µg/ml; SI=6.1) and stem bark (IC50=8 µg/ml; SI>8.00) showed good activity and selectivity against L. infantum. The most active samples against Plasmodium falciparum K1 were the leaves crude 80% ethanol extract (0.92 µg/ml) and its fractions: alkaline aqueous (IC50=0.27 µg/ml), 90% methanol (0.90 µg/ml) and dichloromethane (1.04 µg/ml), respectively, with promising selectivity indexes of 35<SI<237. None of all the tested crude extracts and fractions was found to be cytotoxic against MRC-5 cell lines except the petroleum ether soluble fraction from the leaves which displayed a cytotoxic effect (CC50=21.40 µg/ml).
  
  
  CONCLUSIONS
  Overall, extracts of I. hexaloba tested here, showed good results concerning parasitic infections such as Chagas' disease, leishmaniasis, malaria and/or sleeping sickness without considerable toxicity. The 80% ethanol extracts from leaves and their fractions turned out to be of special interest as they were the most useful in the treatment of malaria.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Kinshasa, P.O. Box 212, Kinshasa XI, Democratic Republic of Congo.
authors.forename: D
authors.initials: D
authors.lastname: Musuyu Muganza
authors.affiliation: Centre for Research and Conservation/KMDA, Koningin Astridplein 20-26, B-2018 Antwerp, Belgium; Faculty of Biology/ Department Biology II, Ludwig Maximilian University of Munich,Großhaderner Straße 2, d-82152 Planegg-Martinsried, Germany.
authors.forename: B I
authors.initials: BI
authors.lastname: Fruth
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Kinshasa, P.O. Box 212, Kinshasa XI, Democratic Republic of Congo.
authors.forename: J
authors.initials: J
authors.lastname: Nzunzu Lami
authors.affiliation: Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Cos
authors.affiliation: Faculty of Pharmaceutical Sciences, University of Kinshasa, P.O. Box 212, Kinshasa XI, Democratic Republic of Congo; Natural Products & Food Research and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Cimanga Kanyanga
authors.affiliation: Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Maes
authors.affiliation: Natural Products & Food Research and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium. Electronic address: luc.pieters@uantwerpen.be.
authors.forename: L
authors.initials: L
authors.lastname: Pieters
mesh_terms: D000818:Animals; D029061:Annonaceae; D000981:Antiprotozoal Agents / Q000302:isolation & purification / Q000633:toxicity*; D018314:Leishmania infantum / Q000187:drug effects; D051379:Mice; D024301:Plant Bark; D010936:Plant Extracts / Q000302:isolation & purification / Q000633:toxicity*; D018515:Plant Leaves; D018517:Plant Roots; D018547:Plant Stems; D014346:Trypanosoma brucei brucei / Q000187:drug effects; D014349:Trypanosoma cruzi / Q000187:drug effects
chemical_list: D000981:Antiprotozoal Agents; D010936:Plant Extracts
keywords: Antiprotozoal activity; Cytotoxicity; Isolona hexaloba; Leishmania infantum; Plasmodium falciparum; Trypanosoma brucei brucei; Trypanosoma cruzi