Abstract
BACKGROUND: Agents currently used for the treatment and prevention of thrombosis have a number of side effects. We conducted this study to develop antithrombotic agents from herbs that are used in food. METHODS: The 80% (v/v) ethanol extracts of Phyllostachys pubescens leaf (PL) and Mume Fructus (MF) and their combinations-2:1 (PM21), 1:1 (PM11), and 1:2 (PM12)-were evaluated on rat platelet aggregation induced by adenosine diphosphate (ADP) in vitro and on arteriovenous shunt thrombosis after 3 days of oral treatment in rats in vivo. RESULTS: At 100 μg/mL, PM21 and PM11 inhibited in vitro ADP-induced aggregation by 44.0 ± 4.3% and 30.0 ± 3.2%, respectively, whereas PL, MF, and PM12 weakly or scarcely inhibited ADP-induced aggregation by 3.9 ± 3.2%, 13.0 ± 2.7%, and 5.2 ± 1.3%, respectively. The IC(50) values of PM21 on ADP-, collagen-, and thrombin-induced platelet aggregations were 135.6 ± 7.4 μg/mL, 142.7 ± 5.8 μg/mL, and 186.5 ± 9.7 μg/mL, respectively. In an in vivo rat arteriovenous-shunt thrombosis model, thrombus weight was significantly decreased after the oral administration of 400 mg/kg PL (27.8 ± 3.0%, p < 0.01) or MF (35.2 ± 2.1%, p < 0.01), and with a good accord to the in vitro results, the combination of PL and MF in the ratio of 2:1, PM21 (60.9 ± 1.2%, p < 0.001), showed a superior antithrombotic effect to those of individual extracts. At dosages of 200 mg/kg, 100 mg/kg, and 50 mg/kg, PM21 dose-dependently decreased thrombosis weight (ED(50), 314 mg/kg). CONCLUSION: These results suggest that combination preparations of PL and MF, especially their 2:1 combination, can increase antiplatelet and antithromboticeffects more than PL and MF alone, offering evidence for a potential novel combination antithrombotic therapy.