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Flaster, T. 1996. Ethnobotanical approaches to the discovery of bioactive compounds. p. 561-565. In: J. Janick (ed.), Progress in new crops. ASHS Press, Arlington, VA.

Ethnobotanical Approaches to the Discovery of Bioactive Compounds

Trish Flaster


The biological diversity of our world is great and we have only begun to investigate her potential. In some areas diversity may be more valuable in its natural state than when used for pasture or timber (Peters et al. 1989). For example, one highly valued marketable commodity of tropical areas is medicinal products. At the present time, half the drugs on the market are derived from natural sources (Reid et al. 1993) and 47 marketed drugs have been derived from 39 tropical forest plants (Farnsworth 1988). Clearly, bioactive molecules from botanicals can continue to be derived from the tropics.

Methods to identify medicinal plant leads from tropical areas include random screening, taxonomic collecting (sampling by botanical family), or ethnobotanical collecting. It has been shown that ethnobotanically-derived compounds have greater activity than compounds derived from random screening and therefore a greater potential for product development (Balick 1990). This paper will concentrate on the ethnobotanical discovery process of plants being used as healing agents as well as environmental and social issues.

Many issues have caused an erosion of the tropical regions of our planet, but for many years only the biological factors associated with this loss have received investigation (MacKerron and Cogan 1993). Recently, it has been recognized that areas of great biological diversity overlap with those of cultural diversity (Manuel Lizzaralde, pers. commun.); when either is disturbed the other is compromised. Clay (1988) and Posey and Balee (1989) have established that the conservation of plants alone was inadequate to maintain an ecosystem because humans are a critical component. Plants are nurtured and manipulated by their human co-inhabitants and only when both are considered as an integral functional group can preservation and conscientious use of species occur.


Ethnobotany is a multidisciplinary science defined as the interaction between plants and people. The relationship between plants and human cultures is not limited to the use of plants for food, clothing, and shelter but also includes their use for religious ceremonies, ornamentation, and health care (Schultes 1992). In the past, ethnobotanical research was predominately a survey of the plants used by villagers. A trained botanist identified the plants and recorded their uses. Sometimes an anthropologist was present to translate the disease descriptions, but rarely was a physician available to identify the disease. The results generated a list of plants and their uses which was published in a professional journal, usually in the country of the scientist. Nothing was communicated or returned to the cultural group in exchange for their participation in the survey, nor was any environmental or cultural status or concerns included in the survey.

Basic quantitative and experimental ethnobotany includes basic documentation, quantitative evaluation of use and management, and experimental assessment (Martin 1995). Today, ethnobotanical surveys include applied projects that have the potential to ameliorate poverty levels of these people, allowing them to make more educated decisions about their future directions. These new approaches enhance the quality of the science, provide compensation for the cultural groups, and take into account environmental concerns. This modern approach is based on an interdisciplinary team usually composed of an ethnobotanist, an anthropologist, an ecologist, and a physician. Some of these team members are in-country colleagues who have arranged the details of the expedition as well as the contractual agreements for reciprocal programs of the village or community.


The initial steps to this approach are critical. Any errors will jeopardize the entire project. To aggressively enter a community or even a country and take out the information is rarely a successful process. However, abiding by the in-country federal requirements will support the goals of a long-term, mutually productive relationship. The negotiations can be done through a trusted colleague, either a person who has worked within the country and is familiar with these procedures or an in-country person. All permits and permissions must be in order prior to the expedition. This process can taken months or years, but regardless of the time period, must be done properly. Many countries are limiting their genetic resources from scientists because of unhappy past experiences and are slowly devising new guidelines. Some, such as the Philippines, are initiating federal legislation which incorporates reciprocity while most others negotiate on an individual basis.

Prior to the expedition, the in-country collaborator can communicate with the village to find out if they have any immediate needs. For example, a five-member team entering a small village must either provide its own food or shelter or provide funds for the villagers to acquire these things. Sensitivity to the community's needs will lay the groundwork for a trusting relationship. The process should be considered as the normal good manners of invited guests. On a scientific level a sincere relationship is needed to ascertain the real data. A superficial personal relationship will yield a superficial scientific relationship (Joly 1992). Many plants are used in village pharmacopoeias, but only a few powerful ones will make it as pharmaceuticals or powerful dietary supplements.

When a research team arrives at the village a customary welcoming ceremony should occur. This is when permission to work with the healers is requested from the village leader or chief. It is most appropriate at this time to demonstrate your support by offering reciprocity for the information you are about to receive. Reciprocity can be clean water systems, books for their schools, health professionals to visit on a regular basis, or any other program they request. The key here is that it be their request. Most of these requests are not exorbitant, certainly not in excess of $5,000, but this is in addition to payment for the herbs you will be collecting. Be aware of the cultural requirements for payment of the plant collections. Ask your in-country liaison because there are some places where payments are unacceptable and initiate divisiveness between community members.

How the ethnobotanical information is gathered is often a pre-planned technique of the anthropologist or ethnobotanist. The technique depends on whether you want to concentrate on particular disease categories or a general survey, have time for just an interview, or can participate in the process for several months. The key is to elicit objective answers to your questions and to be sure that the diseases you are describing are being understood by both parties. Using signs and symptoms to describe the disease allows for an equal exchange of information. Titles and names can be misleading and unknown. Some native people are often eager to be helpful and may respond positively even if the answer is incorrect. Visual aids are helpful vehicles. This portion of the interview may taken place in the field, in the healer's home, or in a community meeting place. Depending on the culture, it can be with one healer or if the village has several, they may want to offer you a group response. Often because your presence is novel, everyone wants to take part. If the latter is the case, devise plans to work in smaller groups without offending anyone. Often the true healers will stand out from the other general healers.

As the healers identify the plants they use to treat specific diseases, data is recorded, the plants are collected, and voucher specimens are taken. Not all expeditions collect plants, but vouchers are always taken and numbered correlations can be made to the collections. A minimum of one of the collected vouchers needs to be left within the country, another archived at an herbarium for positive identification, and the final one stored under appropriate conditions in the researcher's laboratory. The recording of detailed information during the expedition is crucial for isolating the active molecule and obtaining reliable and reproducible collections for a potential product. No detail is expendable. All the data is entered into a database for future and continual use and returned to all collaborators.

After the plants have been identified to genus, and hopefully species, it is extracted and tested biologically for activity. The critical path is to include the ethnobotanical data into these laboratory processes. The natives are the ethnobotanical technicians and translation of their technical knowledge is required for the discovery of ethnobotanically derived medicines (Schultes 1992). If there is a separation of the field data from the chemistry and biological laboratory assays, the ethnobotanically derived molecule may never be found, or worse, activity could be null. From this point on the process involves chemical and biological assays to isolate the active molecule. This can take from one to nine months or more depending upon the complexity of the molecule and the efficiency and technical competence of the research team. During this time you may need to be acquiring more of the raw botanical material. This allows time to collect more data and compare shipments. Your researchers may know how much raw material would be required from beginning to end of the isolation process. Obtaining this quantity before the process begins may be standard company procedure. Using one lot of material from beginning to end will remove any biological and chemical variation that could exist. However, if collected at the wrong time, activity may only be present in small amounts, if at all.

When isolation and identification of the bioactive molecule is completed and activity is demonstrated, synthesis still may be infeasible or impractical, necessitating further research. Plants have evolved wondrous systems to protect themselves, and it is these "secondary metabolites" that provide flavors and healing substances. However, many plant species have similar metabolic pathways. Running searches to find plants which contain the greatest amount of the same active compound may offer you a choice of species to work with. In some cases, this is very desirable because the plant may be endangered or difficult to import from the country in which it was first found. In these cases the compensation package must reflect these situations.


If you are to acquire more material of a plant already researched, then the challenge begins. If the quality of science was high in your original fieldwork then you have all the details you need to expand the horticultural aspects of the project. If not, collect the missing data on the return to the field. This new data may not have been obvious to the healers or yourself before, yet is important at this stage of the project's development. People have different concepts of time and business so these differences need to be taken into consideration in your scientific planning.

At this point, research funds are needed to determine the factors that may enhance the yield of the bioactive molecule. One needs to speak with the healers and understand how, when, and where they harvest, details about drying, and any other particulars about the plant's collection and use. The subtleties are important. We assume or forget that most native peoples in the tropics are excellent managers of their natural resources (Alcorn 1989; Posey 1992) and the best approach may be to observe and integrate their traditional practices into your sustainable program. Additional studies on distribution and density surveys, soil sampling, and multiple plant part sampling are all needed parameters within the design of an ecologically productive program.

A less obvious goal for most agriculturists is a verification of a potential market for this commodity in-country. Many of the plants being investigated may not yield the "pharmaceutical magical bullet" that is desired and having alternative uses such as dietary supplements may offer your collaborators a viable commodity if your goals change. Regardless of the product's end point, the ethnobotanical process can still enhance cultural values and this can have a long-term consequence. This occurs by expanding markets, initiating market economies for the community, and demonstrating to the youth of the community the validity of the elder's plant knowledge.

Several options exist to proceed once the raw data about the plant is compiled. Extractive reserves (Duke 1981) provide forest dwelling peoples an ecologically managed decentralized system of collection. The indigenous groups or communities, if adequate lands are made available, can grow or actively manage economically valuable plant populations within this reserve. Land can also be dedicated as an ecological buffer zone and comparative study plots can be implemented. These plots would demonstrate if the collections were sustainable by comparing the populations in the buffer preserved zone to the actively managed area. The effect of increasing or decreasing a specific plant's density and diversity in secondary forests will be visible and cultural methods that have little impact on the forest can be designed from the data.

Another approach is to work with individual land owners to grow or manage their lands to provide the desired crop. Working with one person who has acquired land allows for direct and responsive communication. Compensation requirements are simplified. They include paying land and community taxes, require participation in community functions, and direct payment to individuals for services or products rendered. The employment of the local community members offers physical protection for the land and often others begin to request participation onto their parcels. The pride and knowledge this creates will assist you in protecting and developing the land, crop, and future product.

Another approach is to work within a community to provide adequate raw botanicals. Once the community has been identified, an all inclusive meeting needs to be convened through the governing body. The purpose of the meeting is to outline your goals and coalesce them with the community's immediate and future needs. For example, what are their political and compensation needs? Many are required to pay imposed federal costs that are beyond their means. This forces them to sell their timber which eliminates agricultural land or hunting grounds. We have the ability to offer them a choice and these meetings can express these potentials.

The decision of who or where to work can be determined by the original field expedition, but if the community has declined participation, another community within the plant's growth range may be chosen. There are advantages to working within communities that are familiar with the cultural practices and use of this plant, but working in a community that has no past history may allow you to readily introduce new ideas (R. Bye, pers. commun. 1985).

When the community agrees with your project their inclusion in the decision making processes and management of the project is necessary for a successful program (Parione 1995). Without their participation there is always a lack of conceptual understanding which had lead to many failures in the past. How you work within the community is determined by their infrastructure. It may be that you contract each member to produce a little or that there is communal land in which the crop can be grown and profits shared. From my experiences, I strongly urge that one person be appointed or voted as leader of the project. This person helps to complete the work on time by communicating and directing the needs of the group and the goals of the project. Training or supplies may be needed. Typical concerns are how to obtain specified yields, coordinate research and test designs with local or foreign laboratories, acquire files to sharpen tools, hire additional staff, supply more food, purchase or make materials to establish seed beds or seedling containers, implement integrated pest management systems, or identify pollinators or predators of the desired plants. The investments required are not philanthropic expenditures, but the true cost of doing business. Your project will take time and needs must be met during this time.


Culturally sensitive and environmentally sensitive programs are required to successfully acquire data from primitive tropical areas. Valid approaches will become more evident as more collaborative attempts are completed. However, at present, there are not enough data to know which programs are environmentally and socially appropriate. Different programs that are species specific may be required for sustainable production. Very little is known at present on how to even define sustainability. However, we now know that there is a potential for many natural products and that there are many communities who are eager to open their lives to market economies to provide more opportunities for themselves.

Ethnobotanical expeditions can be conducted anywhere that contacts are available and participants agree to cooperate. However, ethnobotanical collecting is a multidisciplinary effort that requires sensitivity to both land and people. The discovery and exploitation of natural products must be a shared program for maximum success. Agricultural programs have other needs and there are many complex decisions that must be analyzed before ascertaining the most appropriate and rewarding approach.


Last update June 25, 1997 aw