Effect of flavonoïds from Arbutus unedo leaves on rat isolated thoracic aorta

Arbutus unedo (A. unedo) is a medicinal plant commonly used to treat hypertension and diabetes in Oriental Morocco. Our previous studies showed that A. unedo has a vascular, diuretic, natriuretic, antiagregant and antidiabetic properties. Our goal was to show the vascular action of two groups of flavonoids (free and heterosidic flavonoids) extracted from the leaves of A. unedo on the isolated aorta of rat. A. unedo leaves were collected from Tazekka Mountain (Morocco). Two flavonoïds-enriched (Genins and Heterosids) and a third final aqueous fractions were obtained using the soxhlet refluxing apparatus and tested in vitro on a phenylephrine-precontracted aorta. Thin layer chromatography analysis of both flavonoïds-enriched fractions was performed with silica gel on an aluminum support. The determination of total polyphenolic was achieved using Folin-Ciocalteu method and the total content of flavonoids was determined by aluminum chloride method. The genins-enriched fraction induced a moderate contraction of aorta while the aqueous fraction caused an opposite effect. The heterosids-enriched fraction induced two distinct effects, a relaxation followed by a contraction of the same amplitude. All these effects are endotheliumdependent but not depending on each another. Moreover, the determination of total polyphenolic and flavonoid contents and thin layer chromatography analysis confirmed the abundance of these compounds in the studied fractions of A. unedo leaves. In conclusion, the vasorelaxant property of aqueous and heterosidic fractions are partly attributed to the presence of the flavonoids compounds. These results confirm the validity of the traditional use of A. unedo in hypertension treatmen

Effects of Juglans regia Root Bark Extract on Platelet Aggregation, Bleeding Time, and Plasmatic Coagulation: In Vitro and Ex Vivo Experiments

Platelets have an important role in thrombosis and haemostasis. Hyperactivity of the platelets has been associated with thromboembolic diseases and represents the main cause of complications of cardiovascular diseases. Crude aqueous extract (CAE) of Juglans regia root bark was evaluated for bleeding time, antiaggregant activity by using agonists, thrombin, ADP, collagen, or arachidonic acid (in vitro and ex vivo), and anticoagulant activity by measuring the clotting parameters: activated partial thromboplastin time, prothrombin time, thrombin time, and fibrinogen dosage (in vitro and ex vivo). The result of this study reported that the strongest antiaggregant effect of CAE in vitro was observed on the ADP-induced aggregation with inhibitions up to 90 %, while, in ex vivo experiments, the inhibition (more than 80 %) was observed with all agonists. Anticoagulant effect of CAE significantly prolonged the TT and decreased the fibrinogen level in vitro and ex vivo without interfering with APTT and PT. The bleeding time in mice and rats was significantly increased by CAE. The antiplatelet and anticoagulant effect observed in this study suggest that Juglans regia could have antithrombotic and/or thrombolytic activities and provide an alternative therapy against thrombotic complications related to cardiovascular diseases