Historical or traditional use: (may or may not be supported by scientific studies): Medicinal use of ginkgo can be traced back almost 5,000 years in Chinese herbal medicine. The nuts of the tree were most commonly recommended and used to treat respiratory tract ailments. A tea of the leaves was occasionally used for elderly persons experiencing memory loss.  Active constituents: The medical benefits of Ginkgo biloba extract (GBE) rely primarily on two groups of active components: the ginkgo flavone glycosides and the terpene lactones. The 24% ginkgo flavone glycoside designation on GBE labels indicates the carefully measured balance of bioflavonoids. These bioflavonoids are primarily responsible for GBE is antioxidant activity and may mildly inhibit platelet aggregation (stickiness). These two actions may help GBE prevent circulatory diseases such as atherosclerosis and support the brain and central nervous system.  The unique terpene lactone components found in GBE, known as ginkgolides and bilobalide, typically make up 6% of the extract. They are associated with increased circulation to the brain and other parts of the body as well as exert a protective action on nerve cells. Ginkgolides may improve circulation and inhibit platelet-activating factor (PAF). Bilobalide protects the cells of the nervous system. Recent animal studies indicate that bilobalide may help regenerate damaged nerve cells.