1. J Ethnopharmacol. 2010 Apr 21;128(3):641-8. Epub 2010 Feb 26.

Effects of leaf extracts from Croton zambesicus Müell. Arg. on hemostasis.

Robert S, Baccelli C, Devel P, Dogné JM, Quetin-Leclercq J.

Department of Pharmacy, Drug Design and Discovery Center, University of Namur,
FUNDP, Rue de Bruxelles, 61, 5000 Namur, Belgium. severine.robert@fundp.ac.be

ETHNOPHARMACOLOGICAL RELEVANCE: The leaf decoction of Croton zambesicus Müell.
Arg. (Euphorbiaceae; syn. Croton amabilis Müell. Arg., Croton gratissimus Burch) 
is traditionally used in Benin to treat hypertension. AIM OF THE STUDY: As
hypertension and thromboembolism are often associated in several cardiovascular
diseases, we studied the potential effects of leaf extracts from Croton
zambesicus on hemostasis. MATERIALS AND METHODS: We prepared the dichloromethane 
and aqueous extracts from the air-dried leaves of Croton zambesicus and separated
the aqueous extract in its aqueous and dichloromethane fractions. The potential
effects of these four extracts/fractions were investigated on red blood cells
integrity using spectrophotometric lysis assays, on primary hemostasis using
platelet aggregation studies and on secondary hemostasis using calibrated
automated thrombin generation assays and coagulation factors inhibition tests.
RESULTS: In the in vitro testing, we found that none of the tested
extracts/fractions exhibit hemolytic or antiplatelet activity. However, they
display a moderate but significant anticoagulant activity which would be mediated
through the direct inhibition of thrombin, FXa and TF/FVIIa. The active
anticoagulant compound(s) seem to be mainly in the aqueous extract and especially
in its aqueous fraction. CONCLUSIONS: This experimental work reported for the
first time the anticoagulant effect of leaf extracts from Croton zambesicus.
These findings are of particular interest as the leaves from Croton zambesicus
are commonly used in infusion by local population and may provide a new natural
source for the development of original anticoagulant agents. Furthermore, this
activity, associated with the vasorelaxant properties of some of its diterpenes
may prove to be interesting for the prevention of cardiovascular diseases in
traditional medicine. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

PMID: 20219668 [PubMed - in process]