Ginkgo(Ginkgo biloba): Ginkgo is an excellent example of why protecting plants and animals from extinction can help create new medicine. Ginkgos are the oldest living trees on earth. They first appeared about 200 million years ago and, except for a small population in northern China, were almost completely destroyed in the last Ice Age. Ginkgo leaves contain several compounds called ginkgolides that have unique chemical structures. The leaves were mentioned in a major Chinese herbal text of the Ming dynasty in 1436 and another in 1505. A standardized extract was developed in the past twenty years in Germany to treat a number of conditions associated with peripheral circulation.⁴⁵ It is currently licensed in Germany for the treatment of cerebral dysfunction, with the following symptoms: difficulty in memory, dizziness, tinnitus, headaches, and emotional instability coupled with anxiety. It is also licensed as a supportive treatment for hearing loss due to cervical syndrome and for peripheral arterial circulatory disturbances, such as intermittent claudication (a severe pain in the calf muscles resulting from inadequate blood supply).⁴⁶ Ginkgo leaf extracts are also used for heart and eye diseases, and accidents involving brain trauma. At least three volumes of technical papers on the chemistry, pharmacology, and clinical studies on Ginkgo biloba extract have been published.