|Traditional Medicinal Plants (Dar Es Salaam University Press - Ministry of Health - Tanzania, 1991, 391 p.)|
|PART I: USE AND PROMOTION OF TRADITIONAL MEDICINAL PLANTS IN THE AFRICAN REGION|
Obafemi Awolowo University
Tropical countries of Africa, Asia, Latin America and developing countries of the South have more than 200,000 plant species out of 300,000 plant species available on earth. Because of inadequate health care, people in developing countries die daily of preventable and curable diseases associated with malnutrition.
As a result of the deplorable economic and health status of man in Africa, there is a need for re-evaluation and maximisation of potentials, such as, medicinal plants and other natural resources, for the alleviation of diseases and improvement of nutrition and sanitation.
In this paper a call for the production of plant derived drugs in the countries of the South is advocated and a recommendation is made to establish an international organization for the South to coordinate activities related to:
· exchange of information on medicinal plants;
· promoting and protecting the interest of the Southern countries in the world medicinal plants market;
· and arranging for the production of drugs from medicinal plants for certain uncommon or non-Western tropical diseases, etc.
More than 200,000 out of the 300,000 plant species on the earth are in the tropical countries of Africa, Asia, Latin America and the developing countries of the South, whose experts are gathered together for this meeting. The developing countries also share a number of other things in common that are relevant for our consideration. The developing countries are characterised by extremely limited resources, poor communication, vast distances, individual and community poverty, etc. These factors act upon one another and leave the developing countries in a perpetual state of poverty. Because of inadequate health care measures, people in the developing countries die daily of preventable and curable diseases, often associated with malnutrition.
While per capita income for man in Africa, for example, is of the order of $100 (in Mozambique) to $360 (in Kenya), the figure is from $19,380 (for U.S.A.) to $27,000 (for Switzerland).
The life expectancy at birth in Africa (as at 1988) is equally discouraging: 42 years for Guinea and Sierra Leone, compared with 75 years for U.S.A. and 78 years for Switzerland. This deplorable situation of the economic and health status of man in Africa, calls for a re-evaluation and maximisation of potentials like medicinal plants and other natural resources for the alleviation of disease, and improvement of nutrition and sanitation.
Since the 1968 meeting of the OAU/STRC on medicinal plants of Africa, held in Dakar, Senegal, and several African countries have started screening their medicinal plants for biocactive principles such as antimicrobial, antihelmintic, antihypertensive, antisickling, antiviral, antimalarial etc. The structures for the bioactive compounds (e.g., Khalid et al.,) from the plants have been characterised in many cases, but in some cases, compounds of interesting organic structures are still being isolated and characterised without any link to the biological activity reported in the plant (e.g. Fakunle et al., 1989; Boum et al., 1989).
The status of drug production from medicinal plants in Africa
Drug production from plants in Africa is definitely at a negligible stage Apart from Egypt, most of the other countries in Africa still depend on imported synthetic drugs, while only a few produce up to 20% of the drugs they need locally. In fact, in the case of Nigeria, as much as U.S. $3 m worth of laxatives were imported in 1977 alone, when several plants with laxative properties grow in that country and are prescribed regularly by traditional healers for their patients.
One of the problems hindering the production of drugs from plants in Africa, was the absence of a continent-wide pharmacopoeia, to control the quality of medicinal plants to be used in such drug product and in trade. For a long tune, Egypt has had its own Egyptian pharmacopoeia which contains a host of medicinal plants, their uses, dosage and pharmaceutical formulations. An African pharmacopoeia describing about 100 medicinal plants, their uses, dosage, pharmaceutical preparations, and specifying standards to be met by commercial samples, was produced in 1985 and 1986 by the OAU/STRC in two volumes. Volume 1 contains monographs of the plants, while volume 2 contains the methods of analysis and quality control to be applied. Other problems hindering drug production from plants in Africa are lack of appropriate machinery, expertise in such techniques, and, of course, finance.
In an effort to remove these problems, the African Biosciences Network (ABN) has put up a proposal to the UNDP for funds to cover a two-phase project to stimulate drug production from plants in Africa. Phase 1 is to gather information on the existing facilities for drug production in African countries; locate expertise already available, and set up a data bank which will be used in phase 2 by consultants, that will mobilise the resources to initiate three pilot drug production projects in three regions of Africa. The actual production of simple extracts, powders, tea bags and essential oils from plants in these three model centres will enable consultants to convince other African governments and entrepreneurs to invest in drug production from medicinal plants in Africa. That project proposal is still being considered by the U.N.D.P.
Part of the phase 1 exercise was completed for Africa by a group of experts under the aegis of the Economic Commission for Africa (E.C.A.) in Addis Ababa in 1989. An E.C.A. document resulting from that exercise was published in March 1989 (document No. ECA/IND/CHM/003/8a) titled "Technical publication on the application of research findings in the development of pharmaceutical industries on the basis of indigenous raw materials". This document gives, among others, flow charts for processing medicinal plants to simple dosage forms; it gives the scales of production suited to African conditions and needs; description of processes; quality control; specification of major equipment required; as well as an analysis of manpower and investment requirements. The design of two simple extraction units were also provided by UNIDO in the document. A list of African medicinal plants that yield active principles and/or intermediates is provided, along with a list of medicinal plants recommended for commercialisation. A list of institutions conducting research and development in Africa on medicinal plants is also provided.
Unfortunately, like many useful publications needing only exploitation, few African countries will actually take the bold step to produce drugs from plants, as simplified in this document, unless there is some constant external prodding by consultants or experts. This is why the A.B.N. proposal to U.N.D.P. is still so vital for the realisation of large scale production of drugs from medicinal plants by African countries.
The little effort being made to produce drugs from plants and to set up cultivation trials by Rwanda, Kenya, Tanzania, Ghana and Madagascar are worthy of praise and should be encouraged.
Although some 55, 000 species of plants (including the 10,000 or so which are endemic to Madagascar) exist in Africa, these have not been developed or cultivated to any appreciable extent for drug production.
Medicinal plants and drug production in Asia
My experience after travelling to India and China is that, we in Africa are still lagging far behind in the field of medicinal plants development. For years, India and China have produced drugs from plants, and it is difficult to differentiate a package of a plant-derived drug, from that of a synthetic drug coming from China, in terms of the quality of the finished product.
Large scale plantations of medicinal plants that exist in India and China have an organised collection system by the rural dwellers for plants growing wild on the mountains. These collection systems supplement the cultivation plantations, and help to keep the large scale manufacturing machines going, on rotational basis, for the production of the various plant drugs.
In April/May 1989, an Indian trade mission went to the European Economic Commission (E.E.C.) in Brussels, in connection with the impact of 1992 on the medicinal and aromatic plants and pharmaceuticals from India. India's efforts with the E.E.C. in Brussels is a good forward looking move, especially as that country's plant-derived drugs also meet standards required abroad. China already exports large quantities of medicinal plant products, either in the form of the crude plants, purified extracts, or active principles isolated from plants.
African countries can benefit from a cooperative effort with India and China, for the development of medicinal plants in Africa, by obtaining expertise on the preparation of liquid extracts, dry extracts, tea bags and other simple dosage forms of presentation of medicinal plants in standardised form for the population. Cheap equipment for processing plants, appropriate technology and expertise, can be acquired through a South-South collaboration among developing countries which I hope will be evolved at this meeting. 1992 will come and E.E.C. will be stronger. It is necessary for the developing countries to plan now for modalities for a southern solidarity, in the exploitation and exportation of medicinal plant products.
There may be need to set up a small organisation among the developing countries of the South to specify standards and control measures. Plant products that are already commercial products in some Southern countries, but which plants do not grow in Africa, should be imported for prevalent African diseases, while Africa exports purified or finished products of its own plants to the other southern countries and the developed world.
Such an organisation can help to prevent a situation that was once proposed, that Africa should produce plenty of spices for export because Asia is making plenty of money from the same trade. If Africa were to produce the same spices, the situation will be disastrous for Asia and, eventually, for Africa also in the long run. However, a coordinated effort, through an international organisation for the South, can take care of the following points:
(a) Information exchange among the southern countries producing medicinal plants.
(b) Harmonisation of tariffs where similar products are made.
(c) Removal of geographical trade barriers.
(d) Promoting and protecting the interest of the southern countries in the world medicinal plants market.
(e) Promoting solidarity in bargaining.
(f) Encouraging partial purification of the plant extracts rather than selling raw materials only. This is because it has been shown by U.N.I.D.O that prices increase ten-fold just by selling a purified extract instead of the raw plant.
(g) Encouraging the development of machinery for processing medicinal plants at village level.
(h) Arranging for the production of drugs from medicinal plants for certain uncommon or non-western tropical diseases, e.g. orphan drugs. The development of drugs for tropical diseases may not be pursued vigorously by the multinationals.
(i) Ensuring that many countries of the south are not producing and selling the same drugs, as this will flood the market.
(j) Ensuring diversification.
(k) Arranging for periodic meetings of member countries to exchange experiences, compare notes, review progress and plan strategies for the future.