MEDICINAL PLANTS ASSOURCES OF NEWTHERAPEUTICS'Walter H. Lewis2 andMemory P. Elvin-Lewis2ABSTRACT Indigenous peoples traditionally use a wide range of plants to maintain their health. Modern medicine has benefitedsubstantially from anecdotal results of their empirical methodology by selecting needed candidates for a currentlyinadequate pharmacopeia to treat large numbers of illnesses. When the rapid destruction of diverse tropical forests,where the majority of cultured peoples using traditional medicine live, is related to the recent upsurge of interest infinding new antiviral, antineoplastic, and other agents, there is ample reason to justify learning what plants peopleuse, how they use them, and under what circumstances the plants prove efficacious. These often ignored ethnobotanicalfindings set the stage for targeting plant materials that can be meaningfully analyzed for activity using appropriatebiodirected assays and, when these are significant, for chemical isolation and characterization of active principles.Examples of ethnomedicinally selected western Amazonian plants used by Jivaro Amerindians having potential valueby modern medical standards are described and evaluated. There is great scope for new drug discoveriesbased on traditional medicinal plant use throughoutthe world (Cox et al., 1989; Farnsworth, 1984;Farnsworth & Soejarto, 1991; Moerman, 1991;Phillipson & Anderson, 1989; Schultes & Raffauf,1990; Turner & Herbda, 1990; Tyler, 1986). Ina recent review, Lewis (1992) outlined several hun-dred plants by medical category currently used inmodern medicine and pharmacy, illustrating recentselections of natural products and their incorpo-ration into modern pharmacopeias. He also showedhow a culturally intact tribe, the Jivaro, use plantsnow, as they have for perhaps thousands of years,for health care on a daily basis. However, as hestated, "Serious dangers exist for the survival ofsuch peoples and their cultures, and the ecosystemswhich nurture them and provide Western and tra-ditional medicines with novel plant products forhuman well-being everywhere. In this race againstecosystem destruction, researchers in many dis-ciplines must rally to provide the impetus to saveglobal diversity while, at the same time, acceler-ating studies of ethnomedicine in consort with bio-medical and chemical teams for developing newnatural products and drugs needed by humans intothe next century." As about three-quarters of thebiologically active plant-derived compounds pres-ently in use worldwide have been discovered throughfollow-up research to verify the authenticity of datafrom folk and ethnomedicinal uses (Farnsworth etal., 1985; Soejarto & Farnsworth, 1989), it isreasonable to conduct ethnobotanically directed re-search in order to optimize the search for novelpharmaceuticals. This paper will examine five topics relating toethnomedicinal targeting of plants as potentialsources of new therapeutics: (1) initial collectionof medicinal plants for screening, (2) evaluation oftargeted collections, (3) plants as sources of drugs,(4) ethnomedicine of western Amazonian plants,and (5) intellectual property rights.1. COLLECTION OF MEDICINAL PLANTSFOR SCREENING There are a number of different ways to obtainplants for screening. These range from "random"or biodiversity-based selection to selections basedon taxonomic, chemical, or ethnobotanical data, orany combination of these and other approaches.To date, most large plant collections are obtained"at random," with a goal of procuring as diversea taxonomic representation as possible. The firstNational Cancer Institute (NCI) "random" pro-curement program (1960-1980) had severalguidelines: a sample consisting of any plant partor combinations of plant parts would be acceptableif the sample could be supplied in an amount of 1 ' We thank Gordon Cragg, Chief of the Natural Products Branch, National Cancer Institute, for testing crudeplant extracts in the NCI's anti-HIV screen. 2 Department of Biology, Washington University, St. Louis, Missouri 63130, U.S.A.ANN. MISSOURI BOT. GARD. 82: 16-24. 1995.