A note on the utilization and commercialisation of traditional medicine

E.N. MSHIU,* J.G. SAYI,** & P.M. SARUNGI***

*Traditional Medicine Research Unit
Faculty of Medicine
Muhimbili Medical Centre

**Department of Clinical Pharmacology
Faculty of Medicine
Muhimbili Medical Centre

***Department of Orthopaedics and Trauma
Faculty of Medicine
Muhimbili Medical Centre
P.O.Box 65001
Dar es Salaam, Tanzania

ABSTRACT

Third World countries have no mechanisms to safeguard sovereignty over their genetic resources or for conservation of tropical products and traditional knowledge of the indigenous people. Advances in biotechnology have prompted rapid interest among biotech and pharmaceutical companies to exploit herbs and microbes in the south, as a source of raw materials for new pharmaceutical products.

This paper gives a general review on the utilization and general economic values of medicinal plants world wide.

Introduction

Tanzania has one of the richest vascular flora in Tropical Africa, with over 10,000 species. But most of the species, particularly those with medicinal values, are constantly being threatened as a result of industrialisation, villagisation and other developments.

In the past there have been many instances whereby plants used in the traditional pharmacopoeia of developing countries, such as Tanzania, have been exported and are now available as modern, industrially processed pharmaceutical preparations. In addition, there are many others which, because of their long standing use in traditional pharmacopoeia, are receiving closer attention.

There are also many other plants which have recently been shown to exhibit promising clinical effects, and which could be processed industrially into modern medicines for use in both developing and the more developed countries. Few of such plants are those which can be used as laxatives and purgatives, for example, Cassia absus, C. alata, C. obtusifolia, Tamarindus indica and Phytolacca dodecandra.

Indeed, many species of vascular plants have for long supplied us with excellent drugs such as morphine from papaver somniferum (used as a pain killer), digitoxin and digoxin from Digitalis lanatan and D. purpurea (for treating congestive heart failures), quinine from Cinchona spp. (for malaria), ergotamine (for migraine headache), from Claviceps purpurea and vincristine from Vinca rosea (for treating leukaemia in children). In addition, the natural plant drugs have served as useful prototypes for even better medicines. With the help of synthetic chemists, morphine has become hydromorphine; lysergic acid has been converted to methylysergide; cocaine has yielded procaine; physostigmine has been converted into neostigmine and salicin has been changed into acetylsalicylic acid.

The world statistics

There is no comprehensive world list on medicinal plants and the pharmaceutical products derived from them. However, the national trade statistics of many developed and some developing countries show the contribution to world trade, made by economically important vascular plant-based drugs, and the trend of their contribution. Over 400 botanical products arc marketed internationally. These find applications in a wide range of industries, such as food, cosmetics and pharmaceutical industries.

With regard to the plants used for pharmaceuticals, the imports of the vascular plants into the U.S.A. in 1980 were nearly 34,000 tons worth $78 million. The imports into the European Economic Community were 80,738 tons worth $180 million. The exports from the USA and the EEC in 1980 were, in contrasts, 4000 and 7,300 tons respectively. (Principe, 1989).

The total worldwide imports of medicinal plants increased from $355 million in 1976 to $551 million in 1980. In the Federal Republic of Germany, the imports of medicinal plants in 1979 amounted to 28326 tons, and were worth $56.8 million while imports of medicinal plants to the United States declined from $52 million in 1976 to $44.6 million in 1980. With respect to the domestic market for the plants, the monetary value in the USA in 1981 was $3.912 billion. In Japan, the imports grew from 21,000 tons in 1979 to 22,640 tons in 1980. But the value of those imports declined from $50 million to $48 million (Principe 1989).

The prescription drugs, in contrast, on a world-wide scale, comprised a value in excess of $87 billion in 1984 (in manufacturers prices). That was an increase of about 1.75% over the 1983 figures. The 1985 sales were projected to increase to over $90 billion (in manufacturers prices). In Japan, 13 per cent of the pharmaceuticals found in the 10th edition of the Japan Pharmacopoeia are derived from plants. The demand for these drugs has been increasing over the last decade, but their production only accounts for 1.5% of the total production. In 1984, the sales of traditional medicines in Japan by prescription totalled $227 million (Principe 1989).

In the Federal Republic of Germany, new plant drug preparations, and new plant constituents are continually being introduced into the market by a relatively large number of manufacturers. An interview with women, carried out in the country, showed that 76% of the respondents drank herbal tea for their beneficial effects and about 52% turned to herbal remedies for their initial treatment of minor ailments (Tyler, 1986).

Drug development

The cost of drug development in the U.S.A. is between $50 to 100 million dollars per new product. Because of the high costs involved the activity is restricted to a few of the largest pharmaceutical manufacturers. In the Federal Republic of Germany, the case is different: the smaller companies have the resources needed in innovations pertaining to the plant drug field. This stimulates competition and encourages new product development.

The process of proving whether or not a plant drug is effective and absolutely safe is very costly, a doctrine of reasonable safety should be substituted after clinical trials by general practitioners have given the necessary evidence, and after the experiments have been repeated and the scientific truth verified by the manufacturers and other researchers. In doing so a number of plant remedies will be added to the market, particularly those commonly used for self-medication and those widely prescribed by physicians for minor ailments. But regulatory measures, as now practiced, are still necessary in order to protect public health. Nevertheless these should not be so strict as to discourage and prevent innovative research.

References

Balandrin, M.K., J. Wurteh, E. and W. Bollinger. 1985. Natural plant chemicals: sources of industrial and medicinal materials. Science, 228:1154.

International Trade, Centre UNCTAD/GATT. Markets for selected medicinal plants and their derivatives (undated).

Principe, P. (1989). The economic value of biological diversity among medicinal plants. OECD Environment Monograph. Organization for Economic Co-operation and Development. Paris.

Proceedings of the Workshop on the Pharmaceutical Industry (Combined Modern Traditional Pharmacy) for Promoting Technical Cooperation Among Developing Countries. (1985). UNIDO Technical Papers, /10/R.121 and /10 615: 5-103.

Tyler, V.E. (1986). Plant drugs in the twenty first century. Economic Botany, 40, (3).