Artemisia Dracunculus, Punica Granatum and Berberis Vulgaris Inhibitory Effects on Platelet Adhesion and Coagulation Factors in Rats

Excessive platelet activity is one of the most important factors responsible for the incidence of cardiovascular diseases and, also, play important role in coagulation cascade. In this study, the comparative effects of methanol extracts of three herbs on adhesion of the activated platelets to fibrinogen coated plates and clotting factors were investigated. Artemisia dracunculus, Punica granatum and Brberis vulgaris are used as blood anti-coagulatory plants in Iranian folk medicine. Platelets were prepared and incubated with different concentration of the test samples (50-200 μg/ml) for 60 min. The treated and un-treated platelets were then activated with thrombin (0.25U/ml) and their adhesions to fibrinogen coated plates were investigated. Based on obtained data, the methanol extract of Artemisia dracunculus, Brberis vulgaris and Punica granatum at a concentration of 200 μg /ml reduced platelet adhesion to coated wells by 35%, 25% and 20%, respectively. In addition, the effects of the crude extracts of each plant on atherogenic lipoproteins were also examined. The results indicated that the LDL and cholesterol concentration were dramatically reduced by 56% and 36%, respectively, by B. vulgaris. This result provided the scientific basis for the traditional use of A.dracunculus and B. vulgaris in treatment of cardiovascular related disorders. INTRODUCTION: Platelets, derived from megakaryocytic cell, are anucleated blood elements. Platelet adhesion to extracellular matrix proteins such as immobilized fibrinogen, vonWillbrandfactor, fibronectin and collagen is one of the initial steps of platelet activation for haemostasis maintenance . Haemostasis is the most important body’s defense to control hemorrhage which if carried too far, it can block blood vessels with thrombi and lead to unstable angina and myocardial infarction . As soon as an injury occurs, platelets become activated by the generated thrombin, adenosine diphosphate (ADP) and collagen and then, they adhere to extracellular matrix proteins through various glycoprotein (GP) receptors expressed by the platelets . Platelets, after activation by agonists, express cell membrane glycoprotein (GPIIβ/IIIα) for adhesion to fibrinogen. Both in the formation of the blood clot and in cell adhesion, fibrinogen plays a central role in blood coagulation . Under unphysiological conditions, inadequate platelet function might occur which leads to bleeding whereas plethora platelet activation plays an important role in arterial occlusion and progression of atherosclerosis that eventually leads to thrombosis . Agonist activation of platelets will induce membrane exposure of phosphatidylserine (PS).