Inhibitory effects of urinary metabolites on platelet aggregation after orally administering Shimotsu-To, a traditional Chinese medicine, to rats

Abstract

Abstract Shimotsu-To, which consists of four herbal extracts, has been used clinically for improving abnormal blood coagulation, fibrinolysis, atherosclerosis and chronic inflammation in Japan and China. We have investigated the pharmacological relationship between the effects and chemical components of Shimotsu-To after oral administration to rats. The urinary constituents were separated and identified by three dimensional (3D-) HPLC equipped with a photodiode array detector as a new tool and the chemical structures were determined by spectroscopic methods to be trans-ferulic acid-3-O-sulfate (1), vanillic acid (2), m-hydroxyphenylpropionic acid (3), trans-ferulic acid (4) and cis-ferulic acid (5). Of these compounds, 2–5 strongly inhibited platelet aggregation induced by ADP and arachidonic acid. Compound 1, the sulfate conjugate of 4, did not show any inhibitory effect, which suggested that the inhibitory effect on platelet aggregation was inactivated by sulfate conjugation. These results indicated that compounds 2–5 partly contributed to the anti-Oketsu effect of Shimotsu-To through the inhibition of platelet aggregation.