Abstract: Cyclovirobuxine D (CVB-D) is a compound extracted from Chinese traditional plant Buxus microphylla, which has been used for treating arrhythmia and myocardial ischemia in China. In this study, we investigated its effect on blood coagulation and thrombotic formation in mouse and rat models. The doses of CVB-D used in this study (5-20 mg/kg) prolonged clotting time (CT) in a dose-dependent manner (P<0.01). It also significantly prolonged thrombin time (TT), prothrombin time (PT) and activated partial thromboplast time (aPTT) (P<0.05 or P<0.01) at the doses of 10-20 mg/kg. CVB-D did not affect the bleeding time (BT) compared with the control group, while warfarin significantly prolonged the bleeding time. CVB-D at the doses of 5-20 mg/kg reduced wet weight of thrombosis (P<0.01). This study demonstrated the anti-coagulation effect and anti-thrombosis effect of orally administered CVB-D without substantially increasing bleeding. These findings suggest that CVB-D probably can be used as an oral anti-coagulant in addition to its current applications.

Key words: Cyclovirobuxine D, Coagulation, Venous thrombosis, Bleeding time