Anti-Ice Nucleation Activities of Tyrosine Peptide.

　We investigated whether trimers of serine, threonine, tyrosine, and phenylalanine which may interact with water molecules and ice, show anti-ice nucleation activity. Only tyrosine trimer had high levels of anti-ice nucleation activity (10.10±0.74℃) at a final concentration of 0.2 mM. This was constant at an activity of 2.0℃ between the 0.01-0.1 mM concentrations, and rapidly increased at 0.1 mM or more. At the final concentration of 0.2 mM or more, the activity of the tyrosine trimer was almost constant (from 9.2℃ to 10.2℃). Although it is lower than the activity against silver iodide, the tyrosine trimer showed an effect on the activity of the ice nucleating bacteria. This is the first report that revealed that trimer of amino acid, especially tyrosine has the supercooling-facilitating activity.

Antithrombotic effect of taurine in healthy Japanese people may be related to an increased endogenous thrombolytic activity.

INTRODUCTION: Prevention of arterial thrombotic diseases has high priority in developed countries. Taurine (2-aminomethylsulfonic acid), which is rich in sea foods, showed antithrombotic effect in animal models of thrombosis. The present study aimed to investigate such effect in healthy human volunteers. METHODS AND RESULTS: In 101 healthy Japanese people the overall thrombotic status was accessed from non-anticoagulated blood sample by the Global Thrombosis Test (GTT). There was no significant correlation between taurine concentration in urine samples and GTT-Occlusion Times (OT; mainly reactivity of platelets). In contrast, a significant inverse correlation was demonstrated between urine taurine concentrations and GTT-Lysis Times (LT; showing spontaneous thrombolytic activity). CONCLUSIONS: Our findings suggest that taurine enhances endogenous thrombolytic activity which could be a mechanism of the earlier observed cardioprotective and antithrombotic effect.

Long-term intake of rosemary and common thyme herbs inhibits experimental thrombosis without prolongation of bleeding time.

OBJECTIVE: Our earlier study demonstrated an inhibition of experimental thrombogenesis after acute administration of rosemary and common thyme. The present study aimed to investigate the effect of long-term intake of these herbs on platelets, thrombus formation and bleeding time. METHODS: Western-style high-fat diet containing 5% or 0.5% dried rosemary or common thyme was given to male 6 week old C57BL/6 mice for 12 weeks. Shear-induced platelet reactivity was measured in vitro by haemostatometry. The antithrombotic effect was assessed by the laser-induced thrombosis technique in the carotid artery of mice. Bleeding time was tested by the tail cut method. Endothelial function was assessed by the flow-mediated vasodilation test. RESULTS: Rosemary (5% and 0.5%) significantly inhibited arterial thrombus formation. Only the higher concentration of common thyme (5%) had a significant antithrombotic effect. In 5% concentration, both rosemary and common thyme significantly inhibited platelet reactivity and enhanced the flow-mediated vasodilation. CONCLUSIONS: Long-term daily intake of rosemary and common thyme has an antithrombotic effect, which is probably due to inhibition of platelets and stimulation of endothelial cells. The antithrombotic effect was not accompanied by prolongation of bleeding time.

Testing various fruits for anti-thrombotic effect: i. Mulberries.

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.