The role and use of ethnomedical data in the research on traditional medicines and medicinal plants

W.M. KOFI-TSEKPO

Traditional Medicines and Drugs Research Centre
Kenya Medical Research Institute
P.O. Box 54840, Nairobi
KENYA

ABSTRACT

Any research work on traditional medicines from medicinal plants has invariably taken its lead from an ethnomedical data in one form or another. Ethnomedical data or information refers to the information on the use of a plant or plants for the treatment of certain disease conditions. It also provides some details on the botanical identity of the plant, the method of preparation, and its use in therapy. However, many researchers in this field have often made very little use of the ethnomedical information in their work;

Consequently the phytochemist is, for example, often faced with the problem of identifying and isolating the active principle(s) from a plant material which contains many compounds. The identification of the compound which produces the therapeutic effects, may be impracticable. It has been found that judicious integration of ethnomedical data with ethnobotanical, phytochemical, pharmacological, and toxicological information on an extract can yield much more meaningful results. This paper presents brief accounts on how this approach has been used on:

(a) the Luo traditional salt, prepared from papyrus reed ash;
(b) the antimalarial preparation from Azadirachta indica; and
(c) a traditional antifertility agent with sustained action.

The use of ethnomedical data can facilitate a rational application of pharmaceutical principles in the phytochemistry, pharmacology, toxicology and therapeutics of medicines prepared from plants. The need for greater use of ethnomedical information in medicinal plants research is discussed in this paper.

Introduction

Ethnomedical data on a traditional medicine provides information on the identity of raw materials, the method of preparation, the administration and the therapeutic indication of the medicine. The data can be obtained from three main sources, namely, from traditional healers; from knowledgeable individuals who are not practising traditional healers; and from various literature sources.

The traditional healer is a very useful source of ethnomedical data. However, it is usually difficult to obtain complete information from this source, because the practising traditional healer considers such information as his source of income, and he is therefore, unwilling to part with it freely. Knowledgeable individuals, who do not practice traditional healing, are much more willing to give information on plants used in traditional medicines. Evidently, using such people is one of the ways of securing reliable information. It should be further noted that, such knowledgeable persons are elders, who find themselves duty bound to treat a disease condition, or to solve a health problem in a community. The literature source of ethnomedical data is often derived from the two sources mentioned above. It can provide valuable leads to the investigation of traditional medicines. Some of the currently available publications that provide ethnomedical data, include those of Kokwaro (1976), Watt and Breyer-Brandwijk (1960), Oliver (1956) and Nadkarni (1960). These literature sources can provide very valuable sources for the investigation of traditional medicines and medicinal plants.

The purpose of this paper is to outline how the above three sources of ethnomedical data collection can be used in order to obtain results that can be readily applied in the health care system.

Correlation of ethnomedical data with pharmacological and toxicological data

The therapeutic indications given for a medication can provide a good lead to the design of pharmacological models that can be used to evaluate the medicine. Thus, in the development of the traditional medicine for malaria (KRM 913), the following studies were done: (a) botanical identification of the plant; (b) preparation of the medicine, according to the traditional formulation; (c) investigation of the preparation, using an in vitro model testing against Plasmodium falciparum; and (d) animal toxicity tests.

A similar strategy was used in the evaluation of a traditional antifertility preparation. The biological model used in stage (c) to establish an antifertility activity, was a mouse.

Correlation of ethnomedical data with phytochemical profiles

The phytochemical profile can provide useful information for correlation. The investigation of the papyrus reef ash, be along the points raised above, will be cited as an example.

With respect to the chemical composition of the extract, it was concluded that the elemental composition of the ash extract could explain the therapeutic efficacy of this extract in hypertension.

Traditional pharmaceutical formulation of Traditional medicines

The mode of pharmaceutical formulation is of critical importance. An understanding of this process can assist immensely in making an evaluation on the principles extracted and their relative stability during the preparation and storage. A preparation that is made by extracting with water only, is likely to contain water soluble compounds only. This aspect can be correlated with the phytochemical studies in order to establish the compounds that are readily extracted in the formulation process.

Discussion

The integration of ethnomedical data which includes formulation, pharmacology, toxicology and phytochemistry, leads to faster means of evaluating traditional medicines. In such medicines or plant extracts, a very large number of chemical compounds can be detected and isolated. However, the identification of the therapeutically active principles can become impracticable because one may be dealing with an extract containing over 50 compounds and ions, some of which may be present in only trace amounts, and yet could be the desired principles. The integration of the type suggested above can provide a basis for targeting the active principles in the following manner: (a) preparation of the extract; (b) determination of its activity, using the pharmacological model; (c) doing further analyses on the fractions and follow-up on their activities; (d) determination of the correlation of this activity with the observed clinical effects.

With respect to the ethnomedical information from traditional healers, this can be very valuable, if the above strategies are pursued. In many cases first hand clinical information can be obtained for designing the correlative studies. However, in some other cases, tangible results can be achieved through the literature or verbal information from knowledgeable persons, without involving the traditional healer at all.

Conclusion

The use of ethnomedical data can greatly facilitate the research on traditional medicines and medicinal plants. It is desirable to use ethnomedical data from traditional healers for guiding to scientific research on what plants or what parts of plants one should test for active substances. However, the other sources of ethnomedical information mentioned above can also yield useful results.

One advantage of using ethnomedical data from traditional healers is that a close working relationship with the traditional healers can enhance the diffusion of scientific methods of doing research to the traditional healers. This kind of interaction can be very useful especially if a formal training programme for the traditional healers cannot be carried out immediately. This approach has, so far, been applied in Kenya in the traditional medicines programme of the Kenya Medical Research Institute. Through this approach it has been possible to upgrade the traditional medicine practices in Kenya, and to promote public awareness on traditional medicine. An operational research is planned to evaluate this development.

References

Kokwaro, J.O. (1976). Medicinal plants of East Africa. East African Literature Bureau, Nairobi.

Nadkarni, A.K. (1976). Indian Materia Medico. Popular Prakashan Private Ltd, Bombay.

Oliver, B. (1960). Medicinal Plants of Nigeria. The Nigerian College of Arts, Science and Technology, Ibadan.

Watt, J.M. and Breyer-Brandwijk, M.G. (1962). The Medicinal Plants of Southern and Eastern Africa. E. & S Livingstone Ltd, London.