Anti-platelet aggregation effects of extracts from Arbutus unedo leaves

  • Mohammed El Haouari Centre Régional des Métiers de l’Education et de la Formation de Taza (CRMEF – Taza), BP 1178 - Taza Gare
  • Hassane Mekhfi Laboratoire de Physiologie et Ethnopharmacologie, Département de biologie, Faculté des Sciences, Université Mohamed Premier, BP 717, 60000 Oujda


It is well known that platelet hyperactivity is a risk factor for cardiovascular diseases such as atherosclerosis, stroke and myocardial infarction. This study aimed to examine the effects of extracts enriched in flavonoids obtained from Arbutus unedo leaves on platelet aggregation. Rat platelets were prepared and incubated in vitro with different doses of the tested extracts, and aggregation was trigged by physiological agonists. Platelet treatment with increasing concentrations (0.1 - 1 mg/ml) of diethyl ether extract (genins = free flavonoids) or ethyl acetate extract (hetrosidic flavonoids) inhibited platelet aggregation evoked by thrombin in a concentration-dependant manner. The IC50 values were 0.22 ± 0.03 and 0.36 ± 0.05 mg/ml for genins and heterosidic flavonoids respectively. Treatment with Arbutus unedo extracts also significantly reduced the initial rate of platelet aggregation. At 1 mg/ml, the rate inhibition was 97.8 ± 0.74 and 90.8 ± 1.55 % for genins and heterosidic flavonoids respectively. In addition, flavonoids significantly inhibited platelet aggregation induced by ADP, collagen or epinephrine. We conclude that Arbutus unedo extracts show antiaggregant effects due mainly to flavonoids. These results may partly explain the traditional use of Arbutus unedo leaves for the treatment of cardiovascular disorders such as hypertension.


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How to Cite
EL HAOUARI, Mohammed; MEKHFI, Hassane. Anti-platelet aggregation effects of extracts from Arbutus unedo leaves. Plant Science Today, [S.l.], v. 4, n. 2, p. 68-74, may 2017. ISSN 2348-1900. Available at: <>. Date accessed: 28 june 2017. doi:
Research Articles


Platelets; Aggregation; Arbutus unedo; Cardiovascular disease; Flavonoids; Rat