Antithrombotic, Antiaggregant and Anticoagulant Effect of Methanolic Fraction of Calamintha officinalis: In vitro and ex vivo Experiments

The objective was to study the effect of Calamintha officinalis methanolic fraction in the prevention of thrombosis and to explore its effect on primary and secondary hemostasis. The antithrombotic activity was evaluated by using the pulmonary thromboembolism experimental model. Platelet aggregation, tail bleeding time and coagulation assays were explored to elucidate the antithrombotic mechanism. For aggregation, washed platelets were incubated in presence of Calamintha officinalis methanolic fraction and then activated by different agonists (thrombin, ADP, collagen). The bleeding time was determined to measure the time between the tail incision and the moment the bleeding stops. The coagulation was explored by measuring prothrombin time, activated partial thromboplastin time, thrombin time and plasmatic fibrinogen concentration. For ex vivo study, the animals were treated by the Calamintha officinalis methanolic fraction (250 mg/kg/day) for 4 weeks. Then, platelet aggregation, tail bleeding time and coagulation parameters was studied. The results indicate that C. officinalis methanol fraction seems to exert in vivo an antithrombotic action (40% of protection). The in vitro investigations also show that this fraction significantly inhibits aggregation, increases bleeding time, coagulation times and reduces fibrinogen concentration. The chronic treatment of animals confirms the precedent data. This study demonstrates an antithrombotic effect of C. officinalis. The observed antiaggregant and anticoagulant effects could explain this activity.