Litchi chinensis Sonn. (lychee), which belongs to the family of Sapindaceae, is a subtropical evergreen tree that is cultivated throughout Southeast Asia, particularly in China. Litchi chinensis has been reported to have anti-inflammatory, antioxidant and antidiabetic activities. However, the antiplatelet and anticoagulant effects of Litchi chinensis have not been reported previously. In this study, we investigated the effects of a 70% ethanol extract from Litchi chinensis (LCE) on platelet aggregation, coagulation and fibrinolysis. LCE dose-dependently inhibited collagen- and ADP-induced platelet aggregation in rat platelet-rich plasma. LCE at 4 mg/ml had a maximal inhibitory effect on platelet aggregation. In particular, the LCE 4 mg/ml-treated group showed almost complete inhibition in the collagen-induced platelet aggregation assay. It also significantly prolonged coagulation times, such as the activated partial thromboplastin and prothrombin time, in rat platelet-poor plasma. We also investigated the fibrinolytic effects of LCE using the fibrin plate assay. LCE increased fibrinolytic activity in a dose-dependent manner. These results demonstrated the antithrombotic effects of LCE and suggest that Litchi chinensis may be a new natural source for the development of antiplatelet, anticoagulant and thrombolytic therapeutics for thrombotic and cardiovascular diseases.
Keywords: cardiovascular; coagulation; Litchi chinensis; platelet aggregation; thrombotic.