Get Involved
About Us
Our Members
Herbal Products: Toxicology and Clinical Pharmacology

Herbal Products: Toxicology and Clinical Pharmacology, 2nd edition, by Timothy Tracy and Richard Kingston (eds). Springer-Verlag New York: LLC; 2006. Paperback; 288 pages. ISBN: 978-159-745-3837. $99.

This title is a completely new update of its predecessor entitled Toxicology and Clinical Pharmacology of Herbal Products by Melanie Johns Cupp (Humana Press, 2000). This new edition provides information about the efficacy and safety of 17 selected herbal ingredi-ents. Herbal Products includes recent information pertaining to the therapeutic application and safety of the following herbs:

Ephedra (Ma Huang/Ephedra sinica, Ephedraceae) (curious, since this herb has been banned as a dietary supplement ingredient in the United States), kava (Piper methysticum, Piperaceae), ginkgo (Ginkgo biloba, Ginkgoaceae), valerian (Valeriana officinalis, Valeriana-ceae), St. John's wort (Hypericum perforatum, Clusiaceae), echinacea (Echinacea spp., Asteraceae), feverfew (Tanacetum parthenium, Asteraceae), garlic (Allium sativum, Liliaceae), ginger (Zingiber officinale, Zingiberaceae), saw palmetto (Serenoa repens, Arecaceae), Asian ginseng (Panax ginseng, Araliaceae), cranberry (Vaccinium macrocarpon, Ericaceae), hawthorn (Crataegus oxyacantha, Rosaceae), evening primrose (Oenothera spp., Onagraceae), bitter orange (Citrus aurantium, Rutaceae), chaste berry (Vitex agnus-castus, Verbenaceae), and bilberry (Vaccinium myrtillus, Ericaceae). This is the order the herbs are discussed in the book, with no rational explanation for such.

Eleven of the original herbal monographs included in the first edition are absent in the second: chamomile (Matricaria recutita, Asteraceae), creosote bush (aka chaparral, Larrea tridentata, Zygophyllaceae), borage (Borago officinalis, Boraginaceae), calamus (Acorus calamus, Acoraceae), coltsfoot (Tussilago farfara, Asteraceae), comfrey (Symphytum officinale, Boraginaceae), skullcap (Scutellaria spp., Lamiaceae), licorice (Glycyrrhiza glabra, Fabaceae), pokeweed (Phytolacca spp., Phytolaccaceae), sassafras (Sassafras albidum, Lauraceae), aloe (Aloe spp., Liliaceae), cascara sagrada (Frangula purshiana, Rhamnaceae), senna (Cassia senna, Fabaceae), cat's claw (Uncaria tomen-tosa, Rubiaceae), and dong quai (Angelica sinensis, Apiaceae). The authors note that the new edition included herbs which had more evidence-based studies to support their use.

With the exception of Steven Karch, MD, (who authored the chapter on Ephedra in both editions), the list of contributors is new, including the editors: Timothy Tracy, PhD, of the University of Minnesota-Minneapolis, and Richard Kingston, PharmD, a widely acknowledged expert on herb safety and co-founder of SafetyCall International. This company provides safety information for consum-ers responding to mainstream household products, OTC drugs, and dietary supplements.

The information contained in each herbal monograph is based principally on original studies about the efficacy and potential toxic-ity of these herbs published in peer-reviewed journals, and highlighting double-blind controlled studies whenever possible. Systematic reviews, meta-analyses, and other reviews are also included.

Each chapter consists of an introduction, which includes a description of the plant and pertinent historical data, and contains these sections: Commonly Promoted Uses, Sources and Chemical Composition of the Plant, and Description of the Types and Quality Assess-ment, which assess various herbal products available in the market. There is also a section titled Pharmacological/Toxicological Effects for each herb, which provides an explanation of the herb's mode of action, as well as its possible clinical effects (if known) in humans.

The editors mention that adverse reactions to herbal products seem to be uncommon compared to those reported for prescription medications. However, various exceptions exist that are sometimes erroneously attributed to causes unrelated to the herb, due to the widespread notion that all herbs are safe because they are "natural."

One of the salient features of the herbal monographs covered in this book includes the information presented in Chapters 1 and 2, which show that the use of certain herbs outside the context of their original application in traditional healing practices may lead to health problems.

Chapter 1 includes information on the alkaloids produced by ma huang (ephedra) and their traditional therapeutic use (in the herb) in the treatment of respiratory conditions by Asian traditional medicine for thousands of years, with practically no problem with toxicity.

In conventional or mainstream medicine, ephedrine, one of the alkaloids obtained from the plant, was applied intravenously to patients for the treatment of hypotension caused by spinal anesthesia. Ephedrine was also used to treat heart blockage and narcolepsy until synthetic pharmaceuticals replaced its use in modern medicine.

Ephedrine has been used for many years in some countries in Europe in order to promote weight loss in morbidly obese patients. In the United States, ephedrine was a common ingredient in various weight loss supplements until its ban (and the ban of all its related isomers, e.g., pseudoephedrine) by the Food and Drug Administration (FDA) in 2004, due to the abusive use of the herb ephedra and its extracts (including its naturally-occurring ephedrine and related alkaloids) and its correlated adverse effects in some individuals.

Chapter 2 describes kava, a plant that has been traditionally used in many islands of the South Pacific to prepare a relaxing drink used in important ceremonies as an "icebreaker," promoting congeniality among participants. Products containing kava extracts had been used for many years in Europe, usually with success, for the treatment of anxiety prior to the restrictions or bans placed on its use by many countries (not including the United States, where it is still available) due to various reports of liver problems associated-but not directly correlated-with the herb and/or its combination with alcohol and certain pharmaceutical drugs.

Some studies indicate that the commercial products made from kava are standardized to only one or two of its many active ingredients. This modifies the effects on the body, compared to the original kava drink, which contains diverse active ingredients which usually do not cause health problems, aside from skin eruptions, when taken in very large doses over long periods of time.

Consistent with its title, the focus of this book is on safety and toxicology aspects of the included herbs. This edition provides updated information regarding the safety, including possible drug-herb interactions, of various herbal products currently in use. It will surely become a welcome addition to the library of various healthcare providers including pharmacists, physicians, nurses, herbalists, and phytotherapists.

-Armando Gonzlez-Stuart, PhDHerbal Research Coordinator, University of Texas, Cooperative Pharmacy Program,El Paso, TX