A/HRC/34/49 Medicinal drugs 13. One of the best-known connections between biodiversity and health is the derivation of medicinal drugs from natural products.13 Humans have relied on biodiversity as a source of medicine throughout our history. The oldest known natural mummy, found in the Italian Alps in 1991 after being frozen for more than 5,000 years, carried Piptoporus betulinus, a birch fungus that reduces inflammation. 14 Famous recent examples include: Cinchona officinalis, a South American tree whose bark produces quinine, a treatment for malaria; Catharanthus roseus, the Madagascar rosy periwinkle, first used as a traditional medicine and then as the basis for successful treatments of childhood leukemia and Hodgkin’s lymphoma; Penicillium citrinum, a fungus whose derivation reduces cholesterol synthesis; and Digitalis purpurea, the purple foxglove, used to treat heart disease. More than half of the 1,355 drugs approved by the United States Food and Drug Administration between 1981 and 2010 had natural origins. 15 Our debt to nature is particularly great with respect to antibiotics, which have saved millions of lives: 10 of the 14 major classes of antibiotics are derived from microorganisms. 16 14. Biodiversity is an irreplaceable resource for new medicines, but we are rapidly destroying the resource before we have discovered all that it has to offer. Only a fraction of the hundreds of thousands of plant species have been studied for their medicinal potential, and other living resources, including the marine and the microbial, remain almost completely unexamined. Species are disappearing before we understand what we have lost, but scientists know of tantalizing missed opportunities. For example, two species of gastric brooding frogs indigenous to Australia had unique reproductive physiology that might have provided insights into how to relieve peptic ulcers. Their potential was lost forever when the species became extinct in the 1980s. Even plants known to be valuable are often at risk. As many as 40 per cent of the approximately 60,000 plant species thought to be used for medicinal purposes are endangered, including plants long important in traditional medicine such as the African cherry (Prunus Africana) and the Himalayan yew (Taxus wallichianai).17 Microbial diversity 15. Another way that biodiversity supports human health is even more pervasive but less widely recognized. Studies indicate that the development of normal immune responses, especially to allergens, requires exposure to diverse natural habitats. 18 Each of us carries microorganisms that interact with the biodiversity in the environment in ways that are critical for “the induction and maintenance of immunoregulatory circuits and tolerance”.19 Environmental microorganisms were “previously ubiquitous and abundantly present e.g. in our food, drinking water and milk”, but as more people live in urban settings and as global biodiversity decreases, these interactions are decreasing as well. 20 The reduced diversity of 13 14 15 16 17 18 19 20 6 Connecting Global Priorities, p. 11. See, generally, Enrique Ravina, The Evolution of Drug Discovery: From Traditional Medicines to Modern Drugs (Wiley, 2011), pp. 107-312. Connecting Global Priorities, p. 165. Ibid. Ibid., p. 11. Ibid., pp. 11 and 165. Paul A. Sandifer and others, “Exploring connections among nature, biodiversity, ecosystem services, and human health and well-being: opportunities to enhance health and biodiversity conservation”, Ecosystem Services, vol. 12 (April 2015), pp. 1 and 7. Tari Haahtela and others, “The biodiversity hypothesis and allergic disease: World Allergy Organization position statement”, World Allergy Organization Journal, vol. 6, No. 3 (January 2013), pp. 1 and 12. Ibid.