title: Effects of extracts and tannins from Arbutus unedo leaves on rat platelet aggregation.
abstract: Many cardiovascular diseases such as arterial hypertension are associated with an increase in blood platelet activity. Arbutus unedo (Ericaceae) is a medicinal plant reputed to treat arterial hypertension, so the present study was undertaken in order to determine the antiaggregant effect. The crude aqueous extract showed an inhibition of thrombin-induced platelet aggregation (IC50 = 1.8 +/- 0.09 g/L, n = 10). The subsequent extraction of Arbutus unedo leaves by successive solvents showed that the methanol and ethyl acetate extracts accounted for most of the antiaggregant activity (IC50 = 0.7 +/- 0.08, n = 9; 0.6 +/- 0.05; n = 9, respectively). The tannins isolated from the methanol extract exhibited a strong antiplatelet effect (% of inhibition = 75.3 +/- 1.4, n = 8) and may be the major chemical compounds responsible for this action. Our results support the traditional use of this plant in the preventive or therapeutic treatment of platelet aggregation linked to arterial hypertension.
authors.affiliation: Laboratoire de Physiologie et Pharmacologie Cellulaire, Faculté des Sciences, Département de Biologie, UFR de Physiologie et Pharmacologie, Université Mohamed 1er, Boulevard Mohamed VI, BP 717, 60000 Oujda, Morocco. hmekhfi@yahoo.fr
authors.forename: Hassane
authors.initials: H
authors.lastname: Mekhfi
authors.forename: Mohammed
authors.initials: M
authors.lastname: ElHaouari
authors.forename: Mohamed
authors.initials: M
authors.lastname: Bnouham
authors.forename: Mohammed
authors.initials: M
authors.lastname: Aziz
authors.forename: Abderrahim
authors.initials: A
authors.lastname: Ziyyat
authors.forename: Abdelkhaleq
authors.initials: A
authors.lastname: Legssyer
mesh_terms: D000818:Animals; D029791:Ericaceae / Q000737:chemistry; D006973:Hypertension / Q000188:drug therapy; D066298:In Vitro Techniques; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D010974:Platelet Aggregation / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013634:Tannins / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D013634:Tannins