The antithrombotic effects of onion filtrates in rats and mice

The prevention of arterial thrombotic disease has a high priority in developed countries. An inappropriate diet is known to enhance the risk for acute thrombotic events, and a regular diet with proven antithrombotic effects might be a beneficial way to prevent disease. The present study was undertaken as part of a series of investigations to examine various vegetables and fruits for antithrombotic activity, and to add to the previously reported data on different onion varieties produced in the northern part of Japan (Hokkaido). For this purpose, a sophisticated method to assess shear-induced platelet reactivity/thrombolysis in vitro (The Global Thrombosis Test, GTT) was used to screen 5 different varieties of onion produced in the middle part of Japan (Awaji Island). The different onion varieties demonstrated a variable effect on thrombosis, and one particular variety, designated ONA-03, appeared to exert an antithrombotic effect. Another variety, ONA-01, appeared to have prothrombotic activity by inhibiting spontaneous thrombolytic activity. The especially effective variety was further investigated using an in vivo, laser-induced thrombosis model in mice. The heat stable antithrombotic activity in vitro and in vivo was demonstrated to be due to antiplatelet activity. The present findings added to the list of antithrombotic fruits and vegetables.