Prevention of platelet aggregation and arterial thrombosis using a modified Shenzhu Guanxin Formula.

OBJECTIVE: Modified Shenzhu Guanxin Formula (mSGF) has beneficial effects in coronary artery disease. Previously, we found that mSGF inhibited platelet aggregation in rats. In the present study we further investigated the antiplatelet and antithrombotic activities of mSGF in rats. METHODS: Rats were orally administered mSGF (4.2, 8.4, or 16.8 g crude drug/kg), the adenosine 5'-diphosphate (ADP) receptor antagonist clopidogrel (7.875 mg/kg), or saline once a day for 7 days. The effects of mSGF on platelet aggregation were measured. Levels of cyclic adenosine monophosphate (cAMP) and phosphoinositide 3-kinase (PI3K) signaling were analyzed by ELISA and western blotting, respectively. The antithrombotic effect of mSGF was investigated using a FeCl3-induced carotid arterial thrombosis model and effects on bleeding time were assessed in a rat tail transection model. RESULTS: mSGF significantly inhibited ADP-induced platelet aggregation in a dose-dependent manner, elevated cAMP levels and inhibited phosphorylation of extracellular signal-regulated kinase (ERK) and PI3K/protein kinase B (Akt). Moreover, mSGF dose-dependently inhibited thrombosis in a FeCl3-induced carotid arterial thrombus model and had a significantly smaller effect on bleeding time compared with clopidogrel. CONCLUSIONS: mSGF represents a potent and safe antithrombotic agent whose antiplatelet activity is probably mediated through blockade of PI3K/Akt signaling and increased cAMP generation.