Herbs of Choice / Tyler

Tyler’s Herbs of Choice: The Therapeutic Use of Phytomedicinals

by Steven Foster

HerbalGram. 2009;84:70-71 American Botanical Council

Tyler’s Herbs of Choice: The Therapeutic Use of Phytomedicinals, 3rd edition by Dennis V.C. Awang. Boca Raton, FL: CRC Press, Taylor & Francis Group; 2009. Hardcover; 269 pages. ISBN-13: 978-0-7890-2809-9. $89.95. Available in ABC's online store.

Those who had the pleasure of knowing the late Prof. Varro E. Tyler (1926–2001), affectionately known to friends and colleagues as “Tip,” almost universally describe him in a single phrase, “a consummate gentleman.” His tireless work as a pharmacognosist, pharmacy professor, dean and university vice-president, author, and mentor to at least 2 generations of scientists deserves accolades. Tyler, like many natural products scientists of his generation, was trained in classical pharmacognosy, imparting skills to identify and assess plant materials based on botanical, microscopic, and chemical characteristics, along with organoleptic assessment. Tyler, and colleagues of his era, saw their once-flourishing academic discipline decline to what nearly became a historical footnote, then rise from the ashes of obscurity to become a global phenomenon.

The academic discipline of pharmacognosy arose in the late 19th century to define a scientific basis for plant drugs that dominated the market and materia medica of the era. As pharmacy and pharmacy education shifted away from plant drugs, pharmacognosy nearly disappeared as an academic discipline. The conventional drug market and research shifted from crude drugs (herbs) to single isolated chemical entities, and pharmacognosy itself became an information foundation for new drug discovery from natural sources. The caveat, of course, was that any lead from nature or the pharmacognosist’s laboratory would provide pharmaceutical companies with chemical building blocks for a new (it hoped) synthetic compound, readily defined, easily patented, and free from the confounding endless variation that nature served-up. Tyler’s published research up until 1980 reflects the prevalent trend of that point in history.

In the 1970s, crude drugs in the form of herbs and herbal teas again appeared in the American market, masquerading as health foods and food additives, rather than as the “drugs” that those like Tyler had always known them to be. Tyler was annoyed by marketing hyperbole, unscientific extolment of the virtues of herbs in what he viewed as uncritical “advocacy” literature along with products of quality he might have thought were akin to floor sweepings. He became an outspoken and tireless critic of what he termed “paraherbalism” and an advocate of what he deemed “rationale herbalism.”

His view earned him the ire of unabashed herbal advocates, who made a concerted effort to discredit his information; criticisms that in large part, if viewed critically rather than emotionally, only go to support Tyler’s own assertions. The great irony on what often seemed to be fear-based personal attacks on Tyler, is the fact that he was at the very core of being one of the greatest proponents of the use of herbal medicine in modern society. However, he insisted that the use of herbs must have rational scientific context, including the regulation of herb products. Ultimately, Tyler and his critics sought the same outcome—the acceptance by modern society of the rightful place of herbs in healthcare.

He felt the Germans had taken a largely rational approach to their regulation of herbs as “drugs,” and he became a tireless advocate for at least a conversation about adopting useful elements of the German regulatory system. His advocacy led to the eventual publication of an English translation of the German Commission E monographs by the American Botanical Council.

Tyler may have sometimes erred in his conclusions not to recommend a particular herb for a particular use because scientific evidence did not support traditional use. He might have expressed his conclusions less emphatically, and perhaps more appropriately worded his opinions to state that science doesn’t support traditional claims—not because science refuted the claim, but because no scientific research had yet been published on the subject.

Therefore, the works of Tyler have to be understood in the context of Tyler’s own worldview. Those who knew him may surmise that it was not useful or wise to engage him in a debate about the scientific validity of homeopathy or the value of organically produced crops versus conventionally grown crops. Yet, they could still sit on his back porch with him and enjoy a mutually favorite Czech beer or discuss mutual literary collecting interests.

It is predictable that a belief that the moon could influence plants would be met with disdain by Tyler. However, if research indicating such a phenomenon was conducted, published, and met with scientific consensus, Tyler would accept the new data or proof and revise his beliefs accordingly.

When one compares various editions of his books, his acceptance of new findings is clearly evident. Tyler’s words, written with eloquence, dusted with subtle wry humor, and peppered with a skeptic’s contempt, will make his titles among the 20th century herb books that are remembered in 2 centuries’ time. Whether one agreed with him or not, he always produced a good read. Tyler’s own words reflect a snapshot in time, yet contain wisdom of timeless value. The contemporary value of Tyler’s work, therefore, requires revision.

Despite some of his critical writings on herbs, with his positive and negative assessments in several editions of The Honest Herbal (revised by this reviewer as Tyler’s Honest Herbal in 1999), Tyler surprised many of his colleagues with the initial publication of Herbs of Choice in 1994. In this book, he made a rational case for notice and acceptance by conventionally-trained health professionals of numerous herbs that he deemed adequately supported by both empirical data and modern clinical trials.

Tyler would have been pleased to find that the third edition of his Herbs of Choice is revised and authored by his friend and colleague Dennis Awang, a natural products chemist and a former Canadian regulatory official. They share a love for accurate use of language, scientific thought, and appropriate regulation of herb products. In the new third edition of Tyler’s Herbs of Choice, Dr. Awang has updated the book with new published studies on important herbs found in the modern market for which scientific evidence supports therapeutic use, whether in selfcare or healthcare.

Like Tyler, Awang does not accept science just because it is published in a scientific journal. He is critical of government-funded research on herbs in the United States with findings primarily published in prestigious medical journals because “some [are] blatantly deficient in appreciation of herbal scientific parameters.” Awang reviews various negative studies on St. John’s wort (Hypericum perforatum, Hypericaceae) and echinacea (Echinacea spp., Asteraceae), among others, and explains the deficiency of the science. Tip Tyler would smile and nod his head in agreement.

In the new edition, herbs that have been the focus of significant research in the last decade such as andrographis (Andrographis paniculata, Asteraceae), butterbur (Petasites hybridus, Asteraceae), gotu kola (Centella asiatica, Apiaceae), bacopa (Bacopa monnieri, Plantaginaceae) and bitter orange (Citrus aurantium, Rutaceae) have been added. Awang, a leading expert on feverfew (Tanacetum parthenium, Asteraceae), has thoroughly revisited this subject. As in previous editions, the third edition of Tyler’s Herbs of Choice is arranged by body systems, conditions, or biological effects, spanning 8 of the book’s 10 chapters. Chapter 1, “Basic Principles,” contains a good deal of practical information with guidelines for using herbal medicines, herbal dosage forms, definitions, and discussion on herb quality. It also retains Tyler’s signature discussions on paraherbalism, rational herbalism, and homeopathy, among other herbal polemics. An Appendix, “The Herbal Regulatory System,” has been updated and expanded by Paul N. Brown and Michael Chan, untangling this evolving milieu of new Good Manufacturing Practices (GMPs) and their effects on the confidence of herb quality. An excellent overview of the current Canadian regulations on herbal products is also included.

Mainstream medical healthcare providers know that a large percentage of patients use herbal dietary supplements as medicines and, in most cases, do not discuss that use with their healthcare provider. Perhaps the harried practitioner avoids broaching the subject with patients because of lack of knowledge of the subject matter. They were simply not schooled in clinical applications of herbs. Tyler’s Herbs of Choice, 3rd edition gives those readers a valuable tool for sorting the wheat from the chaff. It is a practical handbook, written by authors with keen knowledge of the multidisciplinary herbal scientific literature, its strengths, and deficiencies. Tyler and Awang have nuanced expertise in the many facets of natural product science, which adds to the book’s depth and accuracy.

The greatest value of Tyler’s Herbs of Choice, 3rd edition is its ability to give medical practitioners the confidence to understand, recommend, and advise on herbs and phytomedicines of clinical value.