Balance between man and nature
I
Among the countries forming that part of the American con- tinent known as Mesoamerica, Mexico enjoys a special position thanks to the pre-Colombian cultures which once flourished on its territory. The wide variety of climates and soils found here meant that its in- habitants acquired a profound know- ledge of medicinal plants and hence of medical science itself. The ancient Mex- icans collected, catalogued and used these plants, integrating them into a vision of the universe whose basis was as much practical as religious. Although no precise documentation remains to us about the experimentation that must have been undertaken at that time, the information that has been handed down testifies to a broad understanding of the curative properties of Mexico's flora.The chronicles and manuscripts of that bygone age contain descriptions of flou- rishing botanical gardens and parks with rich collections of plants, as well as quite precise information about their use.
Ever since the fusion of cultures that followed the Spanish Conquest in the 16th century, Western medicine has tried to analyse the ancient medical wisdom, hoping to find among such cultural relics as remain a correct interpretation of the vision left by those early explorers. In the course of time a wide spectrum of evi- dence has emerged from a variety of cultural sources, all of it tending to con- firm the balance that exists between man and nature.
As the centuries have unfolded, the rich grain of native knowledge has stead- ily evolved among the mixed-blooded population of Mexico. Rooted in past civilizations and nourished by fresh in- sights into the art of medicine, that grain has ripened into methods of treatment which are quite distinct from those based on modern science, and flourishes today as what we call "traditional medicine".
Unequal development, which in con- 8
BY XAVIER LOZOYA
temporary society mainly takes the form of an unequal distribution of resources, means that not all the population is able to benefit from health care. The result is that 40 per cent of Mexico's population today still has recourse to traditional medicine- the medicine of the poor- which is enshrouded in magic and mys- tery.
On the world scene, the study of her- bal medicine in Mexico is of special interest because of three factors: its rich heritage of curative plants, the continued use of such plants among a large propor- tion of the population, and the wealth of available information- whether historic, archaeological, botanical or traditional.
Moreover Mexico, as a developing coun- try, is grappling with the reality of vast public health problems. The efforts made so far to introduce "Western" forms of
Above: Traditional medicine in Mexico is rooted in the rich soil of folk-wisdom hand- ed down from earlier civilizations.
Right: This old man in the marketplace of Oaxaca, south-central Mexico, is the prod- uct of the fusion of cultures that followed the Spanish Conquest in the 16th century.
Today, 40 per cent of the country's popula- tion still has recourse to traditional medi- cine, enshrouded in magic and mystery but still based on a very practicalfrarnework.
(Photos WHO)
medical care are still far from meeting the demands of a fast-growing popula- tion. In the framework of such social, economic and historic realities, Mexican traditional medicine and the medicinal plants themselves are crucially important to the future development of national public health policies.
If we are to elevate the various combi- nations of treatments and drugs to the point where traditional medicine occu- pies the position it deserves, we have to re-examine and re-value popular medi- cine so as to bring it level with the mod- ern scientific knowledge which now serves the health of many people. In order to undertake this laborious task, a complete analysis is needed of all infor- mation relating to medicinal plants, the way they are used and their characteris-
tics. These studies will enable us to prove
the advantages and benefits of the practi- cal, empirical knowledge which has sur- vived the passage of time. When submit- ted to rigorous scientific analysis, the results could give rise to a new type of research going far beyond the limits of chemical and pharmacological analysis, but not dissociating itself from the anth- ropological reality in which traditional medicine is so deeply rooted.
Starting from this multidisciplinary standpoint and with the object of pro- moting and justifying the usefulness of Mexican medicine, the Mexican Institute of Medicinal Plants (IMEPLAM) has incor- porated its activities within the research programme of Appropriate Technology at the Third World Centre for Economic and Social Studies ( CEESTEM).
We have plenty of information about Mexican medical plants and will confine ourselves here to those with special im- portance for public health, which have been given priority in IMEPLAM's research programme.
Our Institute's systematic study of medicinal plants first of all entailed an interdisciplinary effort to collect a
bibliography of everything published in Mexico from the 16th century until mod- ern times, and to subject it to different levels of interpretation, classification and analysis. This also enabled us to start creating a bank of information on medic- inal plants, already in full swing and illustrating in part what we know about plants with cardiovascular, anti-diabetic and anti-parasitic properties. This infor- mation is being compared with modern botanical studies with the object of iden- tifying a group of medicinal plants which may then be submitted to a global study.
Examining the existing data in Mexico reveals that, although medicinal plants have been the object of research under- taken at various times and according to the different trends of scientific thought that have influenced Mexican science, the vast majority of studies made have been undertaken unilaterally, aiming at isolating the active ingredients but without ever succeeding in creating a national pharmaceutical industry. That is why most studies, while providing useful preliminary information, ought rather to be combined with a social objective- that of upgrading the status of popular knowledge, so as to lend 10
scientific support to the practice of tradi- tional medicine.
Here are some of the most popular Mexican plants, representing the three groups to which priority was given.
Plants with cardiovascular properties:
Talauma mexicana (D.C.) Don. Mag- noliaceae. This large tree with beautiful flowers has been known and used since pre-Hispanic times; its name in Nahuatl (the language of the Aztecs) is Yolox- ochitl or Heart Flower, and was given because of the properties attributed to its flower, bark and leaves as cardiac stimu- lants.
A decoction made from the leaves and flowers is still used to treat various car- diac ailments. Scientific research into this plant dates from the last century when chemical and pharmacological studies confirmed its tonic effect on the heart- increasing the heartbeat, and regularis- ing cardiac contractions.
The chemical composition of the Talauma was at least partially discovered around the 1950s, when it was found to include certain alkaloids such as talau- mine and aztequine. But the relationship
Balance between man and nature
Left: A symbol of Mexico, the maguey cactus flourishes everywhere. Its fleshy leaves yield a juice which is fermented into pulque, the national drink. (Photo WHO) Right: This housewife in the Yucatan peninsu- la takes for granted the fact that the plants growing around her home have medicinal uses.
The study of such plants should serve to upgrade the status of popular knowledge, and thus lend scientific support to the practice of traditional medicine.
(Photo WHO/P. Almasy)
between these substances and the cura- tive effects attributed to the plant remained obscure. Its very extensive use puts it among the most important plants in Mexican traditional medicine.
Casimiroa edulis, Rutaceae. Among the sweet edible fruits described by the Aztecs figure those of the Casimiroa edulis, a tree mentioned in the descrip- tions of the period by the name of
"Cochitzapotl"- the fruit that brings sleep. Today, its use is very widespread almost everywhere in Mexico for the beneficial effects on the blood pressure which are attributed to its leaves and its seeds. Certainly this is the most favoured traditional prescription for producing a slight but long-lasting regularisation of the blood pressure.
Although this fruit has been repeated- ly studied over the years, the experimen- tal proof of its action on the blood pressure has only recently come to light in our laboratories. We have determined how the active ingredient present in the aqueous extracts used as popular reme- dies actually functions. The property at- tributed to the fruit of "soothing one to sleep" has been confirmed as resulting from reduced blood pressure sustained
by dilation of the blood vessels; acting on the autonomic nervous system, this facilitates the spontaneous onset of sleep.
The decoction made from the Casimiroa also contains another substance possess- ing powerful properties as a constrictor of the womb, which explains why this plant is not prescribed for pregnant women.
Plants with anti-parasitic properties:
Chenopodium ambrosioides, L.
Chenopodiaceae. Known in Mexico by the name "Yapotzotl", its Spanish name is Epazote and its US name American wormseed. It figures in the recipe of many Mexican dishes and is widely used as a parasite-expellent. A herbaceous plant with a strong odour reminiscent of camphor and a sharp spicy flavour, it owes its anti-parasitic activity to the volatile oil with a concentration of 0.35 per cent contained in its leaves.
It also contains such alkaloids as que- nodopine, colina and tannin, as well as ascaridole. Its effects are powerful and 20 grammes of the plant administered in the form of a decoction suffices to pro- duce a rapid parasite-~xpellent effect
without apparent side-effects. Toxicolog- ical considerations will require further study. Traditional medicine also uses two other kinds of Chenopodium- foeti- dium and graveolens for the same pur- pose.
Cucurbita maxima, D. Cucurbitaceae.
The seeds of pumpkins cultivated in the hot lowlands of Mexico are used by local people in the form of an aqueous emul-
sion, or as a refreshing drink mixed with
sugar, for treating various intestinal parasites. These remedies have proved effective against tapeworm. They are also used to treat different forms of intestinal parasites since they are often, though incorrectly, substituted for the seeds of Cucurbita pepo L., which has similar but much less specific properties.
Plants with anti-diabetic properties:
Tecoma mollis, H.B.K. Begoniaceae.
Under a great variety of popular names, depending on the region of origin, the
"nixtalaxochitl" refers as much to T. Mollis as to T. Stans, all well-known in traditional medicine for their anti- diabetic action. It is often associated with Leucophyllum tenaxum, which is
similarly employed. Pharmacological studies have shown that aqueous extracts of Tecoma administered orally cause an increase in the level of glucose in the blood and thus help to palliate the types of diabetes for which this treatment is particularly indicated.
Coutarea Latiflora, D.C. Rubiaceae.
Commonly called "Copalchi", the bark of this shrub is traditionally known for its anti-diabetic effect. Its diuretic prop- erties in particular are valid for diabetics, and the increased volume of urine elimi- nated is accompanied within 24 hours by a diminution in the amount of glucose secreted, and results in a general im- provement in the patient's condition.
Traditionally the bark is used in powder form decocted in alcohol and adminis- tered orally.
There are many such representative examples of traditional medicinal plants. The more they are investigated and stud- ied in the light of a science which once more reverts to serving the public good, the more they will contribute to the development of a system of medicine adapted to the needs, the cultural demands and the overall health of our
country.
•
11
