Amanda Haidet Outline for Costa Rica Paper: Medicinal Uses of the Rainforest I. Collecting new drugs from rainforest and background of this A. Losing biodiversity-conservationists try to find new uses of rainforest B. National Cancer Institute has collected about 60,000 plant and marine organisms. C. INBIO- collect samples of plants, insects, fungi, and other organisms. D. Steps 1. Collection (plants dried or frozen)-try to collect plants similar to those already known to be useful or plants known to have an effect on animals. 2. Extraction-samples ground up and extracted in an organic solvent. 3. Screening- in vitro testing of the extracts for anti-cancer, anti-HIV, or other useful activity depending on the source of the screening. 4. Isolation- If extracts shows to have potential, chemists isolate the active material and find its structure. Toxicity is also tested here. 5. Preclinical development and eventually clinical trials and approval by FDA. E. Many times, these compounds found in plants can be chemically synthesized on a large scale for production after they are discovered (used as a blueprint). F. Growing market of natural drugs due to patients’ dissatisfaction with conventional treatment, the idea that natural products are better, more liberal advertising laws, and concerns for the national cost of healthcare. II. Cancer A. Most promising natural products today: 1. From Camptotheca acuminata, tree in China: a. Topotecan- approved by FDA, for treatment of ovarian and small cell lung cancer, currently in clinical trials. b. Irinotecan- approved by FDA for metastatic colorectal cancer, in clinical trials now. c. 9AC-in clinical trials for treating ovarian and stomach cancer and T-cell lymphoma. d. Camptothecin- clinical trials in China. 2. Other marine sources from sea hares, tunicates, bryozoans, and sponges are in preclinical or clinical development to treat cancer. 3. Microbial sources, such as Streptomyces species in preclinical or clinical trials for treatment of solid tumors, lymphomas, hematologic cancers, and leukemia. B. Vincristine and vinblastine from the rosy periwinkle in Madagascar. 1. Vinblastine-discovered in 1950s, drug of choice for several types of leukemia and has raised survival rate for childhood leukemia by 80%. 2. Vincristine- 58% chance of lifetime remission for those with Hodgkin’s disease. 3. $160 million in sales a year for the rosy periwinkle. C. 70% of plants that have anti-cancer properties identified by NCI are found in rainforest. D. Taxol-discovered from the Pacific Yew tree (Taxus brevifolia) and is now the drug of choice for several tumerous cancers such as breast cancer. III. AIDS A. Most promising natural products today(currently in preclinical or early clinical trials): 1. (+)-Calanolide A and (-)-Calanolide B- found in Calophyllum lanigerum and Calophyllum teysmanii, species of trees in Malaysia. 2. Conocurovone-found in a shrub, Conospermum incurvum, in Western Austrailia. B. Prostialin-isolated in 1984 from tree in Samoa. C. Pytomedicines come from plants and have great infection-fighting potential, especially for AIDS infections. C. The traditional African system of medicine uses rainforest plants with protoberberine and related biflavones- these have been found to be active against many microbes. Most promising discoveries: 1. Bitter Kola- treatment of bronchitis and throat infections 2. Grains of Paradise- antimicrobial and antifungal IV. Other Medical Uses of Rainforest plants A. Quinine- alkaloid from bark of the cinchona tree to treat malaria (actual pills are synthesized today though), found in Central America and Africa. 1. 4,000 species of plants worldwide have potential contraceptive possibilities. B. Reserpine from serpentine root for tranquilizers C. Diosgenin and cortisone from Mexican yam for birth control pills. D. Ipecac made from emetine found in the plant, Cephaelis ipecacuanha E. Soil microbes- penicillin from fungi, other antibiotics from streptomycin, aureomycin, and chlorobycetin. F. Due to growing antibiotic resistance, new research must be done to find new sources of antibiotics to treat infectious disease. G. Poisonous bark of several curare lianas, alkaloid used to treat multiple sclerosis, Parkinson’s disease, and other muscle disorders. H. Model for aspirin came from extracts of willow trees in rainforest. I. Plant derived medicines commonly used to treat fever, fungal infections, burns, gastrointestinal problems, pain, respiratory problems, and wounds. J. Fungi produce cholesterol-lowering drug Mevacorb V. Value of Biodiversity A. Today, the 20 best-selling drugs come from natural sources and are worth 6 billion a year. B. Costa Rica contains 5% of the whole world’s species. But 84% are unknown to us. C. Shamans (traditional medicine men) have centuries of experience 1. Help reduce research costs of collecting huge masses of specimens to study. (this is the ethnobotanical approach) 2. Already helped in finding anti-viral drugs in preclinical trials from a plant in South America and an anti-fungal agent in Africa which was traditionally used to treat thrush 3. Shaman Pharmaceuticals, Inc. has screened 262 plants and found 192 to be active- a 73 % success rate! 4. Shamans of Southeast Asia used over 6,500 species of plants for medicine. 5. Most of the money made from the development of these drugs goes to large companies and very little goes back to the shaman of the country where it was discovered-exploitation. (ex. Rosy periwinkle.) 6. “Each time a medicine man dies, it is as if a library has been burned down.” D. 25% of all prescription drugs have extracts from plants. E. Less than 5% of tropical plants have been investigated for medicinal value.
Resources: Balck, Elisabetsky, and Laird. Medicinal Resources of the Tropical Forest. Columbia University Press: New York, 1996. Joyce, Christopher. Earthly Goods. Little, Brown and Company: Boston, 1994. Iwu, Duncan, and Okunji. "New Antimicrobials of Plant Origin." Perspectives on New Crops and New Uses. ASHS Press: Alexandria, 1999. "Medicinal Treasure of the Rainforest." Rainforest Action Network. 2002. Online. http://www.ran.org/info_center/factsheets/05f.html. Taylor, Leslie. "Plant Based Drugs and Medicines." Raintree Nutrition, Inc. 2000. Online. http://www.rain-tree.com/plantdrugs.htm. "Saving What Remains." Mongabay.com. 2002. Online. http://www.mongabay.com/1007.htm. "National Biodiversity Inventory." National Inventory of Biodiversity (INBIO). Online. http://www.inbio.ac.cr/en/invn/Invent.html. Carr, Thomas A. and Heather L. Pedersen. "Rain forest entrepreneurs." Environment. Sept. 1993. Vol. 35, p12. "Questions and Answers About NCI's Natural Products Branch." National Cancer Institute (NCI). 2000. Online. http://cis.nci.nih.gov/fact/7_33.htm. Yoon, Carol K. "Drugs from Bugs." Garbage. Sum. 1994. Vol. 6, p22.