Objective To study the effect of active fractions from Lycopus lucidus (L.F04) on
platelet aggregation and thrombus formation
so as to investigate its mechanism of promoting blood circulation and removing blood stasis. Method The effects of Lycopus lucidus L.F04 on
platelet aggregation induced by ADP in vivo, and thrombosis of
artery-vein by-pass and thrombus formed in circuitous loop in vitro were examined using the blood stasis animal model of rats made by injecting high molecular weight dextran (HMWD). Result The increase of maximum platelet aggregation rate induced by ADP in vivo in HMWD model was evidently inhibited with 0.408 g/kg or 0.204 g/kg of L.F04, and the effect showed a trend of concentration-dependence. As compared with the control, the thrombus weight in rat model of blood stasis increased clearly and its length showed only a trend of increase. Both 0.408 g/kg and 0.204 g/kg of L.F04 had the effect of resisting the thrombus formation, while 0.408 g/kg showed better effects of reducing the thrombus dry weight and wet weight. Both 0.408 g/kg and 0.204 g/kg of L.F04 could inhibit the thrombosis in artery-vein by-pass; the inhibition rates were 27.41 % and 27.14 % respectively. Conclusion Lycopus lucidus L.F04 could significantly inhibit platelet aggregation and thrombus formation.