Most reviews of symposium volumes merely delineate the various chapter titles and their authors. When this has been completed no further space is available, so the review constitutes a table of contents rather than a true critique. It is tempting to follow that procedure with this book. The 16 chapters are quite diverse and range from ethnomedical philosophy to methodologies for investigating potential drug plants to the results of recent phytochemical studies on various traditional medicines. However, instead of the conventional approach, the following comments deal with issues raised in a few select chapters. The authors not discussed will simply have to realize that space did not permit a complete review of the book's contents.
The initial chapter by Paul A. Cox with the intriguing title, Shaman as Scientist: Indigenous Knowledge Systems in Pharmacological Research and Conservation, raises the interesting question as to why, in spite of the success of the ethnobotanical approach, the indigenous medical systems of various lands were denigrated during the colonial period. Cox suggests that the superior technology of the West may have been responsible for this attitude toward cultures lacking such a system.
While this is certainly part of the answer, I would suggest another reason. Indigenous medical systems in most undeveloped countries are curious mixtures of magic and medicine. The inability of investigators to distinguish which was which caused everything to be classified as magic, and the effective remedies were discarded with the ineffective ones. The ability of 18th-century investigator William Withering to select the one useful remedy, digitalis, from a hodgepodge that included 19 presumably useless ones was a rare talent indeed, and one that has been infrequently applied. Chinese traditional medicine today continues to be a curiosity rather than a science because no one has applied the Withering method of selecting the effective ingredient from the host of inactive ones in most Chinese herbal remedies. I view the defamation of traditional medical systems as an admission by Western scientists that they are unwilling, or unable, to separate the good from the bad and therefor e simply discard both.
Investigation by Otto Sticher of a number of plants, including Ficus septica, Piper aduncum, and Boccionia integrifolia from Papua, New Guinea, and Bolivia, has confirmed the folkloric use of these species for the treatment of fungal and bacterial diseases and as tropical remedies for wounds. Sticher concludes that the number of plants found to contain active constituents was much larger when selected for screening on an ethnobotanical basis than when simply picked at random. Thus, the study tends to confirm the utility of the ethnobotanical method.
A chapter dealing with the search for noncarcinogenic sweeteners of plant origin by A.D. Kinghorn, R. Suttisri, and I.-S. Lee contains a curious statement that requires verification. These authors note that their taxonomist colleague D. D. Soejarto, during a field trip to Paraguay in 1981, was unable to find any widespread use of Stevia rebaudiana as a sweetener for bitter beverages such as maté. Yet a 1993 report from the Ministry of Agriculture of that country states that over 50 percent of the population of Paraguay consumes yerba maté, in which stevia herb is commonly used [emphasis added]. It would be interesting to know the reason for the American investigator's failure to observe a practice that appears to be commonplace in Paraguay.
Several of my colleagues at Purdue University have conducted extensive studies on the acetogenins of the Annonaceae, so I read the chapter on that subject by pharmacognosist A. Cavé with special anticipation. It turned out to be a brief but well organized review covering the classification, isolation, structural elucidation (sans absolute stereochemistry), and biogenesis of these interesting compounds in a concise manner. However, the properties of acetogenins that cause them to be of value to the field of traditional medicine -- specifically, their physiological activities and therapeutic uses -- are not discussed. A brief sentence notes "their wide spectrum of biological activities."
Pharmacognosy is the study of natural drugs and their products from all points of view. For many years pharmacognosists concentrated on the taxonomy, morphology, anatomy, and histology of plants, neglecting the active constituents found therein. More recently, their attention has turned to the isolation and structural determination of the constituents to the neglect of the activity -- the raison d'etre -- of those principles. So the concentration of Cavé's review on chemistry alone and its neglect of the facts concerning the application of autogenins proves to be typical of much modern pharmacognostic writing. It is fine as far as it goes, but it does not go far enough. If the science is to survive and prosper, this deficiency must be remedied.
Some of the chapters in the volume dealing with specific chemical compounds isolated from a wide variety of plants suffer from a lack of precision in botanical nomenclature that may cause problems for future investigators attempting to replicate the work. Author citations are frequently omitted from the first mention of the scientific name. With many plants, especially drug plants, laboring under the burden of multiple scientific names as a result of continuing taxonomic revision, an initial author citation is mandatory in scientific writing. Likewise, the editors have failed to require the authors to record the identity of the herbarium in which reference specimens of the plants investigated have been deposited. This, too, may seriously complicate further research on a particular species.
These lapses aside, the volume is a useful one, generally well written, well edited, and, with the exception of the glued-in signatures (so-called perfect binding), well presented by the publisher. It will find a useful place on the bookshelves of all those interested in the chemical constituents of traditional medicinal plants.
Article copyright American Botanical Council.
~~~~~~~~
By Varro E. Tyler