The anti-thrombotic active constituents from Centella asiatica.

The in vitro effects of a methanol extract from the aerial parts of Centella asiatica on shear-induced platelet activation and coagulation were assessed after oral administration to rats, by subjecting non-anticoagulated blood to haemostatometry. 3,5-Di-O-caffeoyl quinic acid, 1,5-di-O-caffeoyl quinic acid, 3,4-di-O-caffeoyl quinic acid, 4,5-di-O-caffeoyl quinic acid, and chlorogenic acid, together with asiaticoside, kaempferol, quercetine, kaempferol-3-O-beta-D-glucoside and quercetin-3-O-beta-D-glucoside were all isolated from the methanol extract. Amongst these, only 3,5-di-O-caffeoylquinic acid showed significant inhibition of shear-induced platelet activation and dynamic coagulation. The reactive curve of the inhibitory effect on the platelet reaction and the dynamic coagulation showed a bell-shape.