Hawthorn, botanical name Crataegus oxyacantha, grows as a thorny shrub with white and pink flowers and berries in Europe, Western Asia, North America and Northern Africa. Modern medicinal parts used are the leaves and flowers whereas traditional preparations use the fruit. The main active constituents of Hawthorn are flavonoids including oligomeric procyanidins (OPCs), vitexin, vitexin 4'-O-rhamnoside, quercetin, and hyperoside. These flavonoids act as potent antioxidants.