Abstract: Among medicinal Piper plants used as traditional Chinese medicines,there are about 1/3 species with the function of promoting blood circulation (Huoxue in Chinese).Crude extracts from 20 Piper plants are active against platelet aggregation.Fifty-one antiplatelet compounds,including alkaloids (47%),lignans (24%),phenylpropanoids (22%), etc,have been isolated from the genus.Kadsurenone,eugenol and hydroxychavicol acetate showed significantly antiplatelet activity in vitro. Moreover,pellitorine,piperlongumine,piperlonguminine and eugenol possessed anticoagulant and antithrombotic effects in vivo. Further study on antithrombotic mechanisms and activity screening in new antithrombotic targets of Piper constituents is warranted.

Key words: Piper, antithrombotic, antiplatelet, anticoagulation