Mediterranean diet has got a favourable effect on life expectancy. One of the crucial components of the diet are onions. In an open and a randomized, placebo-controlled, double-blind, cross-over phase-I study a spontaneous pharmacological effect 5 h after administration of an onion-olive-oil maceration capsule formulation on arterial blood pressure could be demonstrated in apparently healthy subjects. In addition to a decrease in arterial blood pressure, a significant reduction in plasma viscosity and haematocrit were observed. These results are indicating a vasodilative effect of the onion-olive-oil-maceration product. The stickiness of the platelets was reduced. The effects were stronger in subjects with reduced blood fluidity compared to those subjects with normal rheological parameters.

Yoga is known to induce beneficial effects on physiological, biochemical and mental functions in man. Its effects on blood coagulation are not known. A study was conducted in seven previously untrained male adults who underwent a combination of yogic exercises, daily for one hour, over a period of four months. Parameters of blood coagulation were estimated before and after the end of yoga training. The following changes were observed: Fibrinolytic activity increased significantly with a concomitant fall in fibrinogen; activated partial thromboplastin time and platelet aggregation time were prolonged; blood and plasma platelets showed a rise; and both haemoglobin and heamatocrit were raised at the end of the training. These findings suggest that yoga induces a state of blood hypocoagulability. The impact of yoga on prevention of cardiovascular and thrombotic disorders is obvious.

Sulfuric-flavored compounds were extracted from shiitake (Lentinus edodes) and their inhibitory activity against platelet aggregation was investigated. Platelet aggregation induced by arachidonic acid and U-46619, the analog of thromboxane A(2), was inhibited by the essential oil from shiitake that contained lenthionine as a major sulfuric compound. This result indicates that the inhibitory site of the shiitake flavor compounds would be different from that of garlic-flavor compounds because the latter inhibits the passage between arachidonic acid and thromboxane A(2). The effect of the synthesized lenthionine was almost equivalent to that of the essential oil, which indicates that the inhibitory activity of the essential oil from shiitake would be mainly attributed to lenthionine.

INTRODUCTION: The phenolic compounds of olive leaves and olive oils in the Mediterranean diet have been associated with a reduced incidence of heart disease. Accordingly, antioxidant-rich diets may prevent the deleterious effects of oxidative metabolism by scavenging free radicals, thus inhibiting oxidation and delaying atherosclerosis. The process involves phospholipase C activation and arachidonic acid metabolism, and is thought to reduce hydrogen peroxide (H(2)O(2)). In our study, an extract of Olea europaea L. leaves was used. The active phenolic compounds in this extract are part of the secoiridoid family, known for their capacity to scavenge H(2)O(2). The results from this study will help to improve our understanding of effects of polyphenol antioxidants in olive leaf extract on platelet function.

METHODS: Full blood examination (FBE), platelet aggregation, and ATP release were performed on samples from fasting, normal, healthy male subjects. Platelet function at increasing concentrations of oleuropein was investigated through measures of platelet aggregation and ATP release from activated platelets.

RESULTS: Blood analysis (n=11) revealed a significant dose-dependant reduction in platelet activity with olive extract concentrations of 1.0% v/v (P<0.001). ATP Release showed a similar pattern (P=0.02).

CONCLUSIONS: Olive leaf polyphenols derived from O. europaea L. leaves inhibited in vitro platelet activation in healthy, non-smoking males. Further bioavailability studies need to be undertaken to determine the in vivo effect of extract on platelet function and to validate the present results.