RESUMEN
An in vitro anti-thrombin bioassay was developed to investigate the chemical constituents which have anti-thrombin effect from the water soluble components of Salvia miltiorrhiza. Using Chromozym TH as a probe combined with ethyl acetate Semi-micro extraction was applied to measure p-nitroaniline by HPLC. According to the results, the inactivationrate of thrombin by sodium danshensu, salvianolic acid A and salvianolic acid B under a given set of conditions were 3.06%, 77.77% and 2.35%, respectively. In the water-soluble components, salvianolic acid A has a direct inhibition of thrombin, while sodium danshensu and salvianolic acid B have no significant effect on thrombin. The method is sensitive and low consumption. It can eliminate the interference absorbed for the sample itself which can be used for screening single or multiple direct antithrombin active ingredient of herbal extract.