Co-HP inhibited FeCl₃-induced arterial thrombosis and DVT in vivo but did not show a significant increase in bleeding time. (A) Time required to cause vessel occlusion in the FeCl₃ model; a 1 × 1 mm strip of filter paper saturated with 10% FeCl₃ was applied to the adventitial surface of the exposed femoral artery of 1% DMSO- (●) or Co-HP–injected mice (▪; estimated final concentration of 10 μg/mL [15 μM]). The time to thrombotic occlusion of the artery was measured by monitoring femoral blood flow using a Doppler blood flow velocimeter. Each symbol represents 1 individual. **P < .01. Data were analyzed by the Student t test. (B) DVT model: 1% DMSO- (●) or Co-HP–injected mice (▲; estimated final concentration of 10 μg/mL [15 μM]) were subjected to IVC stenosis for 48 hours. Thrombus length (i), thrombus weight (ii), and thrombosis prevalence (iii) were measured. Each symbol represents 1 individual. Lines in dot plots represent medians. Data of the prevalence and of length/weight were analyzed by the Fisher exact test and the Mann-Whitney test, respectively. *P < .05; ***P < .005. (C) Time of bleeding from the cut tail of DMSO- (●) or Co-HP–injected mice (▪). A 1-mm segment of the tail tip was cut, and the tail tip was immersed in saline. Each symbol represents 1 individual. Data were analyzed by the Student t test.