Horse Chestnut Extract Herbal Factors Horse Chestnut and Grape Seed is a superior combination of standardized herbal extracts that benefit varicose veins, chronic venous insufficiency, hemorrhoids and edema. Varicose veins are often caused by enzymes that destroy the proteoglycan network in the veins, which reduces the strength of vessel walls, causing the veins to dilate and pool blood. Aescin (escin), a triterpenoid isolated from horse chestnut, helps to inhibit these damaging enzymes, increases the tone of the veins and improves return blood flow to the heart. Grape seed extract works synergistically with horse chestnut to strengthen blood vessels, reduce bruising and inhibits the tendency to develop varicose veins. The helpful flavonoids in grape seed extract, called proanthocyanidins or leucoanthocyanins, are superior antioxidants, protecting capillaries, veins and arteries from free radical damage. Grape Seed flavonoids enhance the performance of vitamin C, essential for collagen formation.