In previous studies , we have demonstrated that sulphated flavonoids from Flaveria bidentis prolong the aPPT and prothrombin time assays but this effect is not due to a decrease in coagulation factors. In order to establish the mechanism of these sulphated flavonoids on the hemostatic system, the aim of this study is investigate whether antithrombin III (AT III) and heparin cofactor II (HCII) are involved.
Results showed a capacity of sulphated flavonoids to active CHII as judged by decrease thrombin activity as compared to dermatan sulphate. We conclude that sulphated flavonoids affect the hemostatic system by inhibiting thrombin activity mediated by HCII and this might be due to the high degree of sulphatation of this molecule.