Abstract: AIM: To study the effects of the total Astragalus extract on anti-thrombus.METHODS: The thrombus formation in mice was induced by i.v injection of a mixture of collagen and epinephrine.The mice which died within 5 min and remained paralyzed for more than 15 min were observed, and the protect rate were calculated.Furthermore, the lung tissues wese made by histological examination.The blood of rat was gained from abdominal aorta, and the effects of the total Astragalus extract which resolved rat blood clot were tested by tube in vitro.RESULTS: The total Astragalus extract (50 and 150 mg·kg^-1) reduced the death rate resulted from thrombosis induced by mixture of collagen and epinephrine (i.v) in mice.The total Astragalus extract(40, 80, 160, and 320 mg·L^-1) resolved blood clot in vitro.CONCLUSION: Total Astragalus extract has obvious effects of inhibiting thrombus formation in vivo and resolving blood clot in vitro.It suggests the total Astragalus extract has the effects of activating blood to resolve stagnation.

Key words: total Astragalus extract, anti-thrombus, activating blood to resolve stagnation, collagen, epinephrine