Grape Seed (Vitis Vinifera). Polyphenols (previously called bioflavonoids) found in grape seed extract protect the heart and promote healthy veins, arteries and capillaries. An important subgroup of polyphenols in grape seed are leucoanthocyanins or proanthocyanidins. These flavonoids help to strengthen blood vessels, increasing the tone and elasticity of capillary walls, enhance the effect of vitamin C, and help to quench free radicals. That is why Grape seed leucoanthocyanins or proanthocyanidins may be useful in a number of disorders. They improve the biochemical properties of blood vessels, and help different types of vascular disorders including capillary fragility, peripheral chronic venous insufficiency and microangiopathy of the retina.

Grape Seed may help allergy sufferers because the leucoanthocyanins exert an inhibiting effect on histamine release, suppressing allergy symptoms.

Grape Seed has been shown to be helpful against mild and severe artherosclerosis when rabbits were fed a cholesterol-rich diet. It also helped to protect rabbit heart against ischemica/reperfusion injury.

Grape Seed is standardized to contain 85 to 95% leucoanthocyanins (proanthocyanidins), bound to phosphatidylcholine from lecithin.