In vitro antiprotozoal activity and cytotoxicity of extracts and isolated constituents from Greenwayodendron suaveolens.
BACKGROUND
The Nkundo people (Nkundo area of Bolongo, Mai-Ndombe district, Bandundu Province, DR Congo) use various plant parts of the tree Greenwayodendron suaveolens (Engl. & Diels) Verdc. (syn. Polyalthia suaveolens Engl. & Diels) (Annonaceae) against malaria, but its antiprotozoal constituents are not known.


METHODS
The crude 80% ethanol extract from the fruits, leaves, root bark and stem bark and 16 fractions were assessed 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 (Pf-K1). Their cytotoxic effects were evaluated against MRC-5 cells. Active constituents were isolated by chromatographic means, identified using spectroscopic methods, and evaluated in the same assays.


RESULTS
The root bark extract showed the highest activity against P. falciparum K1 (IC500.26µg/mL) along with the stem bark alkaloid fraction (IC500.27µg/mL). The root bark alkaloid fraction had a pronounced activity against all selected protozoa with IC50values <1µg/mL. The 90% methanol fractions of the different plant parts showed a pronounced activity against P. falciparum K1, with IC50values ranging between 0.36µg/mL and 0.69µg/mL. Four constituents were isolated: the triterpenes polycarpol, and dihydropolycarpol, the latter one being reported for the first time from nature, and the alkaloids polyalthenol and N-acetyl-polyveoline. They were active to a various degree against one or more protozoa, mostly accompanied by cytotoxicity. The highest selectivity was observed for N-acetyl-polyveoline against P. falciparum K1 (IC50 2.8µM, selectivity index 10.9).


CONCLUSIONS
These results may explain at least in part the traditional use of this plant species against parasitic diseases such as malaria in DR Congo.
Faculty of Pharmaceutical Sciences, University of Kinshasa, P.O. Box 212, Kinshasa XI, Democratic Republic of Congo. Electronic address: cdmuganza@hotmail.com.
D Musuyu
DM
Muganza
Ludwig Maximilian University of Munich, Faculty of Biology/ Department Biology II, Großhaderner Straße 2, D-82152 Planegg-Martinsried, Germany; Centre for Research and Conservation / KMDA, Koningin Astridplein 20-26, B-2018 Antwerp, Belgium.
B
B
Fruth
Faculty of Pharmaceutical Sciences, University of Kinshasa, P.O. Box 212, Kinshasa XI, Democratic Republic of Congo.
J Lami
JL
Nzunzu
Natural Products & Food Resarch and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
E
E
Tuenter
Natural Products & Food Resarch and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
K
K
Foubert
Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
P
P
Cos
Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
L
L
Maes
Faculty of Pharmaceutical Sciences, University of Kinshasa, P.O. Box 212, Kinshasa XI, Democratic Republic of Congo; Natural Products & Food Resarch and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
R Cimanga
RC
Kanyanga
Natural Products & Food Resarch and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
V
V
Exarchou
Natural Products & Food Resarch and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
S
S
Apers
Natural Products & Food Resarch and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
L
L
Pieters
D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005638:Fruit / Q000737:chemistry; D006801:Humans; D020128:Inhibitory Concentration 50; D018314:Leishmania infantum / Q000187:drug effects / Q000254:growth & development; D021261:Parasitic Sensitivity Tests; D064209:Phytochemicals / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D008517:Phytotherapy; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000254:growth & development; D031044:Polyalthia / Q000737:chemistry*; D014344:Trypanocidal Agents / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D014346:Trypanosoma brucei brucei / Q000187:drug effects / Q000254:growth & development
D000962:Antimalarials; D064209:Phytochemicals; D010936:Plant Extracts; D014344:Trypanocidal Agents
Antiprotozoal activity; Cytotoxicity; Greenwayodendron suaveolens; Malaria; Plasmodium falciparum; Polyalthia suaveolens