Inhibitory Effects of Two Ferulates from Angelica Sinensis on Platelet Aggregation and Oxytocin-induced Uterine Contraction

Ferulic acid (FA) is widely considered as a biologically active component in Angelica sinensis, and used as one of the marker compounds for the quality control of Angelica sinensis. However, in A. sinensis, FA mainly exists as its ester, coniferyl ferulate (CF). CF is unstable and readily hydrolyzed into FA during conventional extraction. Herein, their antiplatelet aggregation activities and relaxant effects on oxytocin-induced mouse uterine muscle contraction were investigated and compared. The results showed that FA inhibited arachidonic acid (AA), adenosine diphosphate (ADP) and thrombin (THR)-induced platelet aggregation with IC50 values of 974.8 ± 97.5, 737.9 ± 40.2 and 244.6 ± 25.6 μg/ml, respectively. The potency of CF is much higher than that of FA, and the IC50 values for AA, ADP and THR were 7.1 ± 0.3, 276.4 ± 53.4 and 77.5 ± 23.1 μg/ml, respectively. IC50 of FA was 23.8 ± 6.2 μg/ml for oxytocin-induced uterine contraction in vitro. CF could only be tested at low concentration and its IC50 could not be calculated thereafter because of its strong hydrophobic property. So CF has more potent antiplatelet aggregation activity, while FA has stronger inhibitory effect on oxytocin-induced uterine contraction in vitro.