The prevention of arterial thrombotic diseases has a high priority in developed countries. An inappropriate diet may be an important risk factor for thrombotic events. The daily intake of an anti-thrombotic diet may offer a convenient and effective way of prevention. The aim of the present study was to test tomato extracts for anti-thrombotic effects and to identify those varieties that have such an effect. A shear-induced platelet-function test (haemostatometry) was used to test anti-thrombotic potential in vitro. Extracts from those tomato varieties that showed a significant anti-thrombotic activity in vitro were further assessed in vivo, using a laser-induced thrombosis test in mice. One tomato variety (KG99-4) showed significant anti-thrombotic activity both in vitro and in vivo. KG99-4 inhibited not only platelet-rich thrombus formation but also had a thrombolytic effect. It is concluded that haemostatometry can detect and classify the anti-thrombotic potential of fruits and vegetables and offers a simple way of screening for such effects.

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Prevention of arterial thrombotic disease has high priority in developed countries. As inappropriate diet predispose to acute thrombotic events, regular intake of an antithrombotic diet may be a convenient and effective way of prevention. The present study was performed to examine antithrombotic effect of mulberry varieties. A shear-induced in vitro platelet reactivity/thrombolysis test (Gorog Thrombosis Test) was used to screen for antiplatelet and thrombolytic activities. In case of effectiveness, it was followed by an in vivo test of laser-induced thrombosis in mice. Antioxidant capacity was assessed by superoxide anion and radical scavenging activities. Total polyphenolics, anthocyanin and citrate contents were also measured. The tested varieties showed different effect in vitro on platelet reactivity and endogenous thrombolytic activity. Varieties inhibiting platelet reactivity were antithrombotic in vivo regardless inhibition or enhancement of thrombolysis. Those mulberry varieties, which enhanced platelet reactivity in vitro, were prothrombotic only if inhibitory activity on endogenous thrombolysis coexisted with the platelet effect. Antioxidant activities and polyphenolics content did not affect platelets and the overall thrombotic status. However, antioxidant activities and polyphenolics content significantly correlated with the endogenous thrombolytic activity. These data showed that mulberry varieties can be grouped into subclasses with either anti- or prothrombotic activities. Antioxidant activities and polyphenolic contents do not affect platelets but may enhance endogenous thrombolysis, thus causing an overall antithrombotic effect.

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Because of the high mortality, prevention of arterial thrombotic disease has top priority in developed countries. As inappropriate diet is known to predispose to acute thrombotic events, regular intake of an anti-thrombotic diet may offer a convenient and effective method of prevention. As part of a systematic investigation into the anti-thrombotic effect of fruits and vegetables, strawberry varieties were tested in this study. An in vitro platelet function test (haemostatometry) was used for screening strawberry filtrates. Those that showed significant antiplatelet effect were further assessed with a laser-induced thrombosis test in mice. Measurement of flow-mediated vasodilation in the femoral artery of mice reflected the effect on the vascular endothelium. Correlation between the effects on platelet reactivity in vitro and the antioxidant activity (hypoxanthine/xanthine oxidase test) or phenolic compound content was assessed. Strawberry varieties KYSt-4 (Nohime), KYSt-11 (Kurume IH-1) and KYSt-17 (Kurume 58) showed significant antiplatelet activity both in vitro and, after oral administration, in vivo. Both KYSt-11 and KYSt-17, but not KYSt-4, significantly reduced flow-mediated vasodilation; that is, caused endothelial dysfunction. Antiplatelet activities were heat stable. Significant correlation was found between antiplatelet and antioxidant activities (P=0.049, R=0.23) or total phenolic compounds (P=0.0096, R=0.36). Of the tested strawberry varieties, KYSt-4, KYSt-11 and KYSt-17 showed significant anti-thrombotic effect. The dual mechanism of the effect may involve a direct inhibition of both platelet function and antioxidant activities.