Anthraquinones in Plants: Source, Safety and Applications in Gastrointestinal Health by Luc Delmulle and Kris Demyer. Nottingham, UK: Nottingham University Press; 2010. Paperback; 170 pages. ISBN 978897676325. $41.95.

Anthraquinone-producing plants are widely used in traditional medicines. Anthraquinones have a variety of interesting biological activities, e.g., astringent, purgative, anti-inflammatory, light-activated antiviral, and insecticidal. However, this book is focused more directly on its subtitle: “source, safety and applications in gastrointestinal health” (this is code for constipation, herbal cleansing), a major area of application. It takes a traditional and comprehensive European pharmacognosy approach to this focus. The book is edited by 2 authorities in herbal medicine with extensive experience in the field, Luc Delmulle and Kris Demeyer of the Vrije Universiteit Brussel, Belgium, with contributions from other European scientists in particular chapters. The objective is to emphasize phytomedicine applications, and the authors achieve it well. The text is highly referenced, technical, and reasonably up-to-date (2008). It will be indispensible for professional herbalists, naturopathic doctors, manufacturers, and regulators who deal with these plant-derived medicines. The book is like Belgian chocolate: very high quality and a little old-fashioned.

Section I of the book describes the botanical aspects of the plants from major genera used for herbal drug preparations (Cassia/Senna, Rheum, Rhamnus, and Aloe). This includes botanical descriptions of the plant and its origin and description of the herbal drug, including organoleptic properties and macroscopic and microscopic characters used for the identification of harvested material. Phytochemical components found in each species, range of concentration, and standards for European and German Pharmacopoeias are included. Some notes on wildcrafting and cultivation are given, including source countries. For example, the major sources of Cassia and Senna (Fabaceae) are India and China, while Rheum spp. (Polygonaceae) are cultivated in China and Korea. Species in the genus Rhamnus (Rhamnaceae) are harvested from different species in the Balkans and the Pacific Northwest of North America, and Aloe (Xanthorrhoeaceae) is cultivated in warm climates worldwide. There is little attention paid in this volume to conservation and sustainable-use issues or good agriculture practices and cultivar development. Ethical issues such as fair-trade production or agreements under the convention on biodiversity are not discussed. However, this section is illustrated nicely with color plates, some line drawings, and phytochemical structures of the anthraquinones. There are no distribution maps and few ethnobotanical details.

Section 2 provides a short description and phytochemical scheme of biosynthesis of the anthraquinones, from a chemistry point of view, but enzymes and genes involved are not reviewed. The redox properties and antioxidant activity are described and there is a short section on photochemistry, but little discussion of the literature on phototoxicity. The review of analytical methods is particularly up-to-date with a discussion of conventional high-pressure liquid chromatography methods with diode array or electrospray ionization mass spectrometry detection (HPLC-DAD and HPLC ESI/MS). Some of the latest publications reviewed cover new techniques such as micellar electrokinetic capillary chromatography (MEKC) and capillary zone electrophoresis (CZE).

Sections 3 and 4 address pharmacokinetics and pharmacodynamics. These interesting and informative sections show that anthrone beta glycosides are stable in the stomach and arrive intact in the large intestine where they are metabolized by bacteria, releasing the biologically active aglycones. Only a small proportion of the aglycones are absorbed into the blood plasma and are excreted into urine. There was little interaction with highly permeable drugs, but interaction with less permeable drugs was not predictable. The mode of action is described as prostaglandin-mediated increase in histamine and serotonin, as well as increased nitric oxide synthase activity.

Section 5 focuses mainly on the clinical use of anthranoid drugs for constipation. There is detailed discussion of dosing. For example, typical doses are 20-30 mg hydroxyanthracene derivatives and a maximum daily dose of 30 mg is recommended by the European Scientific Cooperative on Phytotherapy (ESCOP). Clinical trials are nicely summarized in readable tables. Several studies suggest efficacy of a variety of plant sources of anthranoids for constipation and bowel cleansing in adult populations. The preparations are not recommended for children under 12 but various studies suggest they are safe for intermittent use by pregnant or breastfeeding mothers. Most studies do not suggest any link between anthranoid use and coleorectal cancer. There are no safety concerns when used at normal doses but case reports show adverse events in cases outside of recommended use.

In summary, the book provides a comprehensive review of the scientific literature on application of anthraquinone-producing plants in gastrointestinal health and is highly recommended to professionals in the herbal field. It is a classic and authoritative pharmacognosy text on the topic and shows that anthraquinone-producing plants are effective and safe drugs. I feel very relieved.

— John Thor Arnason, PhD Professor of Biology Director, Biopharmaceutical SciencesUniversity of Ottawa