Imprimir Republish


The lessons of the Krahô Indians

In search of new drugs, researchers identify 164 plants used by the Indians of the State of Tocantins in healing rituals

eduardo rodriguesThe culture of the Brazilian Indians is often the object of anthropological study. However, their medicinal practices, based on the therapeutic use of plants, have been sparsely researched and rarely serve as the basis for the development of new medicines. A project by the medical doctor Elisaldo Carlini, the Director of the Brazilian Center of Information on Psychotropic Drugs (Cebrid) of the Federal University of São Paulo (Unifesp), has taken the first step towards reverting this situation. At least regarding the little knownherbal pharmacopoeia used by a group of by an national indigenous group, the ethnic group Krahô.

During her doctorate, advised by Carlini, the biologist Eliana Rodrigues, spent two years mapping the plants and recipes prescribed by the seven Shamans – healing priests in charge of looking after illnesses and promoting healing rituals – at the three villages that make up part of Kraoland (Kraolândia), the ethnic reserve situated in an area of Cerrado (wooded savanna) in the north of the State of Tocantins. At the end of her survey, promoted through FAPESP, Eliana had managed to identify, with the help of the taxonomists of the Botanical Institute of the State of São Paulo, an arsenal of 164 vegetal species used for medical ends – all of them plants native to the Brazilian flora.

Of this total, some 138 seem to be species with some type of influence on the central nervous system, the area of interest of the research group. Apparently, these plants can cure pathologies or promote behavioral alterations, of humor or cognition. In the vision of the Krahô Indians, some of them are for courting, for marriage and even for separating husband and wife. Others carry with them the fame of increasing physical resistance and are used by the Indians in competitions, in which tree log carrying and the dispute of running races feature among the preferred activities. Others are hallucinatory.

With these 138 species the Shamans prepare 298 curative recipes, destined towards 51 types of indicated therapeutics. “The same plant can be used for more than one finality”, reports Eliana, who visited the settlements ten times, having been invited to spend close to 200 days with the Krahô Indians. For example, depending on how it is prepared, the species known a sahtu in the Timbira language of the Krahô Indian, can be used to solve love problems with a partner or as a strengthener. In order to deal with a determined health problem, usually there are various alternative treatments. In the case of thephyto-therapeutics with analgesic properties, the biologist put together 48 recipes, which use 40 plants.

The prospects of discovering some new drug in this group of almost 140 species with potential action over the central nervous system looks good. After all, we are dealing with, in the vast majority of cases, plants never before analyzed through scientific criteria of Western civilization. Only 11 of the 138 species had been the target of pharmacological and phytochemical studies, and, in only one case, had there been a coincidence between the prescribed use by the Indians and the use pointed to by conventional medicine. “We have research material for more than 20 years”, comments Carlini, enthusiastic with the results of the field work.

“I don’t know of any survey of this size coming from the indigenous culture.” The scientific names of the plants and their possible therapeutic use are being kept in secret. The precaution is justified: the information is valuable and could be improperly used by pharmaceutical laboratories and other research groups interested in eventual economic dividends flowing from the mapping done through the project. “The rights of the Indians will be respected”, assures the doctor. “We have already signed a pre-agreement with the Krahô Indians, who will receive their part if we develop commercial medicines from their knowledge.”

Since the quantity of information and plants obtained together with the Krahô Indians is so great, even when they worked only with those seem to have some effect on the central nervous system, Carlini and Eliana decide to steer their efforts towards five categories of interest: species with analgesic effects; those that help control weight; that have hypnotic/anxiety control action; that act upon the memory and the learning process; and those named adaptogens (increase physical resistance). If they hadn’t proceeded in such manner, the risk of the project losing its focus would have been great.

The idea is to choose two or three plants of each one of these categories and to concentrate the pharmacological studies on these ten to fifteen species. The remainder of the material collected in the survey will remain, for now, outside of the front line of study. “It wouldn’t be possible to research all of them”, comments Eliana. “We had to establish some priorities, in spite of having found curious practices outside of our category of interest, such as the use, among the women, of plants to promote fertility or to inhibit, temporarily or permanently, conception.”

The major part of the phytotherapics carried out by the Krahô Indians is administered in the form of teas, made from one or various parts of the plants, entire or grated. The Shamans can also apply as a topical remedy over the body of a patient, parts of the vegetal or use them for preparing cigarettes, baths or inhalations. In some cases, leaves and roots of some plants are eaten by the sick person, since the Indians believe that the therapeutic properties are in the juices of these vegetal. During the exercising of their function, the Shamans, called wajacas in the Timbira language, smoke pipes filled with tobacco, marijuana and other hallucinatory plants. The smoke is blown over the patients. Depending on the case, the wajaca can spread it over the body of the sick person, in an attempt to better “visualize” the illness. Or, perhaps, concentrate it on the one spot so that he can “suck out” the illness, extracting the evil malady from the organism of the sufferer.

On the day following this ritual, generally done at night, the Shaman makes up a recipe with the plants which, in his vision, are going to help a colleague in the village. To check on the effect of their preparations, they visit each of their patients. If a recipe doesn’t work, then he tries another. “Like our very own doctors, the Shamans of the Krahô Indians specialize in one or more illnesses”, comments Eliana. “Some look after snake bites, common colds and so forth.” Obviously sometimes there is no treatment that works. Death is seen by them as the fruit of an accident, sorcery, or illness.

Why did the Unifesp researchers decide to study the work of phytotherapics among the Krahô Indians, present only in Tocantins, instead of some other national ethnic group? The answer: these people were the ones who most closely resembled the desired profile. They were in a forest area whose flora has been poorly studied from the ethno pharmacological point of view, the Cerrado. Carlini and Eliana didn’t want to work with human groups established in the Atlantic Rain Forest or the Amazonian Rain Forest, ecosystems where one finds the greater part of the botanical/pharmaceutical research is concentrated.

Moreover, the idea was to meet with three other fundamental prerequisites: they made use of rituals and hallucinatory plants during their medical practice; they had among their members, specialists in the practice of curing; and they were to be found in a geographically isolated area, without access to the public health network. “Many Indians don’t know what is aspirin”, says Eliana, who, while working in the field was assisted by her brother Eduardo Rodrigues, who is on a trainee at Unifesp. The biggest town closest to the Krahô Indian village is Carolina, in the south of the state of Maranhão, with a population of 24,000 and at a distance of around 12 hours by car. The journey, by dirt road, can only be done by a vehicle with four-wheel traction, normally a pickup truck.

The process of the discovery of a drug is always long. It is true that the option of conducting the research starting from the indications of phytotherapics used by the Indians shortens a little this trail. After all, before beginning the scientific studies, the researchers already have a notion of what the sphere of action of a possible medicine could be. Even then, there are a series of stages that need to be overcome to prove the efficiency – and that it is non toxic – of a medicine.

When one is working with phytotherapics, one of these stages is to foster the cultivation of the native species that shows potential to generate medicines, thus creating a controlled source of the plants that will be the target of new collections. This has been happening in the villages since last June, with the help of the agronomist Kátia dos Santos, who is advising the Krahô Indians on the best agricultural procedures. In possession of the chosen plants, the researchers prepare extracts and begin the scientific analyses in laboratories. The species that are the candidates to generate phytotherapics are initially tested on animals, in order to determine if their use has any risk.

If this stage is approved, the vegetal extracts follow through a series of experiments with human beings. In this new battery of tests, their toxicity is again investigatedand the efficiency as a drug against some health problem is determined. Next, the researchers must establish in what dose the medicine should be prescribed and what are the eventual side effects. The Unifesp researchers don’t have the pretension of finding the main active ingredient of the plants that prove to be helpful for generating medicines. They only want to determine and to guarantee the commercial registration of their extract from which is produced a phytotherapic. “For each plant that reaches the end of this process, we abandon ten along the way”, estimated Carlini. This is after taking five years of research and some R$ 2 or R$ 3 million in investments.

Nonetheless, the medical doctor is convinced that it is cheaper to look for drugs amid the rich national biodiversity – Brazil is among the seven countries in the world with the greatest number of vegetal species – than to work through the chemical synthesis of medicines, as the large multinational laboratories do. “This is a great opportunity for the Brazilian pharmaceutical industry”, says Carlini. In order to accelerate their research with the phytotherapics indicated by the Indians, the Unifesp project is now looking to establish partnerships with the private sector.

The Aché Laboratory, the largest national pharmaceutical company, is one of those interested in financing the studies. “We missed the boat in the generation of drugs starting from refined chemical synthesis”, says José Eduardo Bandeira de Mello, the general Director of the company. “If Brazil doesn’t go firmly into the research of phytotherapics, we will miss the next boat.”

Massacres and migrations: the saga of the sons of the rhea
Of the thousands of members of the Krahô Indian people who made their first contact with Western man at the end of the 18th century, when they then inhabited the state of Maranhão, close to 400 Indians survived in the decade of the 30s, possibly the most critical moment in their history. The target of innumerable massacres and resettlements, the remnants of the ethnic group migrated to the south, went up the Tocantins river and settled themselves in an area where, in 1944, the Federal government set up their reservation: 302,000 hectares of the Cerrado in the north of the State of Tocantins, in the municipalities of Goiatins and Itacajá.

The National Indian Foundation (Funai) demarcated the lands of Kraolândia (Kraoland), as the reserve is named, only in 1975, and its official approval came much later in 1990. Today the members of this ethnic group have reached around 1,700 Indians. The reserve has 16 villages and 58 Shamans. Through interviews and questionnaires applied through seven of these priestly healers, the biologist Eliana Rodrigues, of Unifesp, made her survey of medicinal plants used in three villages, Serra Grande, Forno Velho and Aldeia Nova, the first two of difficult access.

Each settlement is built around a circular patio on the edge of which are erected the dwellings. The number of inhabitants can range from 40 to more than 250 people. Among their leaders are the Chief (pahi) and the Mayor, as well as the Shaman. The men look after the hunting, fishing and the preparation of a small planted area. Besides taking care of the house and their children, the women cut wood, and not rarely, perform the same tasks as the men. Their houses are made of mud, with roofing made from palm leaves, without running water or electricity.

In few villages there are schools, maintained by a non-governmental entity, the Indigenous Work Center (Centro de Trabalho Indigenista -CTI). The lessons are in the Timbira language – the Indians who speak Portuguese only use our language to communicate with people from the towns. The interests of this ethnic group are defended by an entity that represents various Timbira speaking peoples among them the Krahô Indians, named the VYTY-Cati Association. In their language, the Krahô Indians name themselves Mãkrare, which literally means the sons of the rhea. The parallel between the Indians and the animals makes sense. Just like this animal itself, the members of the ethnic group like to wander in the Cerrado, but they always come back home. This is the destiny of the Indian. 

The project
Traditional Uses of Psych Active Plants by Two Human Groups in Brazil: A Reflection on Symbolic Efficiency and Active Principals (98/14217-0); Modality: Regular Line of Research Assistance; Coordinator: Elisaldo Carlini – Unifesp; Investment: R$ 45,887.50 and a doctorate scholarship