LEUNG'S
(CHINESE) HERB NEWS
Number 30
January/February 2001

Herbs in this issue:

Asian ginseng

Ginkgo leaf

 

A Note From Dr. Leung

 

I was going to take a break from reviewing the Complete Guide to Herbal Medicines, but obviously am not very successful.  The following are some comments by a renowned colleague, Dr. Varro E. Tyler (‘Tip’ to his friends).  Tip is well known and respected among academic and industrial colleagues.  To the lay public, he is probably best known for his The Honest Herbal and as one of the most quoted scientific herb experts.  After reading my critical comments in previous issues of this newsletter on this “Complete Guide,” here is what he had to say: “Prompted by your interesting negative reviews of Fetrow and Avila’s The Complete Guide to Herbal Medicines, I acquired a copy at the local Barnes & Noble just to see for myself what was in it.  (I hated to do so because sales will encourage the authors, but I was curious.)  Perusal of most of the monographs revealed that the volume is even worse than you made it out to be.  I dare say that there is at least one error

 

 

Dr. Leung is author of the Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics (Wiley-Interscience), which was published in 1980 and revised in 1996. He is also creator of PHYTOMED, a prototype computer database on Chinese herbal medicine developed under contract with the National Cancer Institute.


 

of fact or interpretation on every single page of the text.  How the authors could persuade a reputable but herbally challenged physician like Margolis to write a glowing forward and a division of Simon & Schuster (Pocket Books –Springhouse) to publish it is beyond my comprehension.  By the way, this book is 698 pages long!  Thanks, Tip.  For a while I thought I was being too harsh on this “complete guide” (Issues 27-29).

  

The Chinese Herbal (Zhong Hua Ben Cao)1

         This work is by far the most extensive undertaking ever realized in the field of botanical medicine!  The field of Chinese materia medica (herbal, animal, and mineral drugs) is the most extensive in the world.  Its scope has expanded from a handful of drugs recorded around 1,000 BC to over 12,800 by the last decade.1,2  Two of the best-known herbals are the Shen Nong Ben Cao Jing (Shennong Herbal) (circa 100BC-100AD) and the Ben Cao Gang Mu by Li Shi-Zhen (circa 1590-1596).  The former describes 365 drugs while the latter 1,892 drugs.  Among the 20th-century herbals is the Zhong Yao Da Ci Dian (Encyclopedia of Chinese Materia Medica) compiled by the Jiangsu College of New Medicine and published in 1977.  This describes 5,767 drugs and covers the scientific (pharmacological, medical, and chemical) literature up to 1974.  This work was considered the most extensive documentation of Chinese traditional drugs up until September 1999, when The Chinese Herbal was published.1  I had been keeping an eye out for it and finally located and bought a set last June in Hong Kong.  It consists of 10 volumes, totaling 9,282 pages, with 8,534 illustrations and 8,980 drug/food monographs.  To give you an idea of what these numbers mean, each page of this Chinese text, when translated into English, will yield 3 to 4 pages of printed English text.  Thus, if this work were published in English, it would consist of 30 to 40 volumes of 1,000 pages each.  The Chinese Herbal was compiled by the Chinese State Administration of TCM involving over 500 scholars/experts from at least 60 academic and research institutions, and took 10 years to complete.  This monumental work was published by the Shanghai Scientific and Technical Press.  It has a Forward by the Chinese Minister of Health, Zhang Wen-Kang, dated May 10, 1999, and a Preface by the Editorial Committee, Chinese State Administration of TCM, dated May 18, 1999, along with a commendation (calligraphy) by Li Peng, a Communist leader, which bears a date of December 28, 1998.  The official price in China is set at 2,560 RMB (~US$310).  But if you buy it in Hong Kong, it will cost you HK$4,096 (~US$530).  In either case, even including shipping, it would still be a fraction of what comparable works in English would cost – quite a bargain.  Furthermore, major bookstores in Hong Kong and China will ship the books for you and, at least from my experience, are totally trustworthy, because the many times I have bought from these bookstores I have not yet received damaged books or missed any due to their handling and shipping. 

         Volume 1 of The Chinese Herbal contains 633 pages of text plus 8 pages of 113 colored photographs of excerpts from historical herbals and mineral drugs, of which 258 pages are devoted to general topics, including: historical development of herbals, from 2 millennia before the famous Shen Nong Ben Cao Jing (circa 100 BC to 100 AD) to the present time (48 pages); geographical sources (4 pages); cultivation (8 pages); collection and preliminary processing (10 pages); storage (12 pages); classification according to traditional and modern criteria (6 pages); types, including synonyms, substitutions, adulteration, etc. (11 pages); identification and quality control, including organoleptic, macroscopic, microscopic, and physicochemical evaluation (19 pages); phytochemistry, including all major chemical classes (alkaloids, coumarins, lignans, quinones, flavonoids, terpenoids, steroids, lignins, saccharides, amino acids, peptides, glycosides, etc.) (49 pages); pharmacology (14 pages); curing/processing methods and rationale (10 pages); preparations, including traditional and modern dosage forms (10 pages); compounding and dispensing, including incompatibilities (10 pages); and traditional properties, including principles of combinations, dosage, toxicity, contraindications, etc. (42 pages).

         The rest of Volume 1 (370 pages text) deals with drugs derived from minerals, algae, fungi, and lichen.  There are 114 mineral and 205 plant drugs described here.

         Volumes 2 to 8 deal with traditional drugs derived from other plants, from moss and bracken to gymnosperms and angiosperms, arranged in what appears to be phylogenetic order, with the most advanced orchid family coming last.  Described therein are 7,610 traditional drugs. 

         In Volume 9, there are 1,051 animal-derived drugs described, including those from marine sponges, corals, crustaceans and fish, as well as land and celestial animals such as insects, reptiles, and mammals.  There are also the following addenda: (1) Close to 600 drugs described in classic herbals (including mineral, plant and animal), whose identities cannot be verified or whose uses are unclear.  They are provided here with documentation from major herbals.  (2) TCM theoretical considerations based on examples from classic references, including the topics of compound prescriptions, drug properties and preparations, treatment theories, incompatibilities, contraindications, and cautions.  (3) Description of 100 major herbals, from the classic Shennong Herbal to Li Shi-Zhen’s Ben Cao Gang Mu (circa 1590-1596), to the more recent Zhong Yao Da Ci Dian (Encyclopedia of Chinese Materia Medica) published in 1977, and the Xin Hua Ben Cao Gang Yao, published in 1988-1991.  (4) A listing of approximately 1,800 major publications on herbs and foods (with titles and authors) in chronological order by dynasty, starting with the Qin-Han era (221 BC – 220 AD), ending before the current regime.  All but 4 of the above-mentioned 100 herbals (which were published after 1950) are included in this listing.

         Lastly, Volume 10 is an appendix that includes in order of appearance:  (1) A Chinese drug index (251 pages).  (2) An index of Latin binomials of plants (96 pages) and animals (10 pages), as well as English names of minerals used as drug sources.  (3) A Chinese index of phytochemicals with English translation (200 pages).  (4) An English index of phytochemicals with Chinese translation (196 pages).  (5) An index of chemical structures in English with Chinese names as well (754 pages).  (6) An index of pharmacological activities (based primarily on experimental findings) arranged in categories such as CNS, neural transmission, cardiovascular, hematological, digestive system, respiratory system, urogenital, hormonal, immunological, antimicrobial, antitumor, and others (12 pages).  (7) An index of traditional properties based on TCM practice (36 pages).  (8) A therapeutic index covering all major categories of diseases or conditions for which the drugs are used: internal medicine; pediatrics; obstetrics; gynecology; trauma; dermatology; ophthalmology; ear, nose and throat; dentistry; etc. (84 pages).  Most are TCM based. 

         This new Herbal is a tremendous resource for anyone interested in Chinese herbal medicines or foods for whatever reason.  There is something for everyone – the traditional practitioner who wants to see what has been used for certain conditions, the phytochemist looking for unique compounds, the pharmacologist looking for specific activities exhibited by certain herbs, the pharmaceutical chemist searching for leads to new drugs, or someone like me who is interested in broad aspects of Chinese natural medicines/foods.  The indexes are extremely useful tools, which allow you to zero in on what you want in no time.  The modern/scientific literature covered in The Chinese Herbal goes occasionally up to 1994, but most to 1991 or 1992, especially for non-Chinese references.  Depending on the particular drug, the literature cited for the best-known traditional ones is primarily Chinese, while more recently introduced or ‘discovered’ Chinese drugs contain mostly non-Chinese (English, Japanese, etc.) citations.

         As an illustration of the scope of this herbal, I have selected 2 common herbs that are familiar to most Americans, namely, Asian ginseng and ginkgo leaf.  The monographs start with the drug/herb names, e.g., renshen for ginseng and baiguoye for ginkgo leaf, along with citations from the classic herbals in which they were first clearly described.  For Asian ginseng, the herbal cited is the Shennong Herbal and for ginkgo leaf, it is the Ben Cao Pin Hui Jing Yao (circa 1505 AD).  Types of information presented include the following topics, in sequence:  (a) synonyms; (b) interpretations of classical records; (c) historical descriptions of the herb and its sources, etc.; (d) source of the drug; (e) botanical names (Latin binomials) and description of the plant(s) along with habitats and geographical distribution; (f) cultivation; (g) collection and processing; (h) areas of production and distribution; (i) identification, including organoleptic, macroscopic, microscopic, and physicochemical evaluation, and commercial grading; (j) chemical constituents; (k) pharmacologic activities; (l) processing or curing; (m) traditional nature (taste, channel affiliation, toxicity, etc.); (n) traditional properties or functions and indications; (o) applications and combination rationale and strategies; (p) methods of administration and dosages; (q) cautions; (r) selected classical prescriptions; (s) selected modern formulations or preparations; (t) modern clinical research and applications (not comparable to U.S. clinical trials involving single-chemical drugs); (u) theoretical considerations of properties and functions based on classical treatises; (v) additional comments from classic herbals on sources, physical appearance, collection, properties, and uses, etc.; and (w) references.

         Not all monographs contain all above categories of information.  For example, Asian ginseng, being one of the most documented and well-known Chinese tonics, contains considerable amount of information in all above categories, citing 204 references, only 34 of which are non-Chinese.  Most of the information presented is appropriate and useful, which is based on clearly identified traditional materials (root powder, decoction, extracts, preparations, etc.) as well as chemical fractions and specific chemicals.  Dozens of classical herbals are quoted when detailed information in traditional properties, functions, cautions, contraindications, prescriptions, and other topics, is presented. 

         In contrast, ginkgo leaf has never been a popular herb in traditional Chinese usage until its specific extracts (containing flavonoids and terpene lactones) became popular in the West.  Now the Chinese are one of the major suppliers of ginkgo leaf extracts to the American market.  The information in the ginkgo leaf monograph reflects the non-Chinese nature of this new information and new usage.  In this monograph, only two-thirds of the above information categories are supplied with data, some meagerly.  And only 2 classic herbals are cited, primarily for its internal use in diarrhea and leukorrhea and its external use in freckles, sores, and swellings.  Its uses in cardiovascular and cerebrovascular conditions are supported only by post-1970 literature, including Chinese herbals and journals.  Among 113 references cited, only 20 are from Chinese journals, most are dated between 1980 and 1991.  Despite the extensive chemical and pharmacological information presented, it is not easy to ascertain what types of ginkgo leaf preparations or extracts were responsible in producing the reported pharmacologic effects.  There is a repeated reference to GbE which is described as a ‘ginkgo leaf preparation extracted with either water or alcohol as reported in the Chinese literature or extracted with unknown solvents as reported in the foreign literature.’  Apart from a few instances where ‘total flavonoids’ or ‘GbE flavonoids’ are specifically identified, GbE is reported throughout as the extract(s) that produced the reported cerebrovascular, CNS, cardiovascular, antioxidant, anti-platelet aggregation, bronchial muscle relaxation, and other effects, supported by most of the cited references.  There is no mention of the flavonoid/terpenoid (24%/6%) extract on which most of ginkgo leaf’s modern research is based which has led to the current applications of ginkgo leaf extracts. 

As I have repeatedly stressed in this Newsletter (Issue 19, pp. 2-3; Issue 27, p. 3), it is extremely important to clearly identify what one uses in one’s research in natural medicines and in reporting or abstracting the herbal literature, otherwise the resulting information will be of little value to other researchers and misleading to the general public.  Which is, I believe, one of the major reasons why frequently, despite so much research having been performed on a particular herb or its derivatives, no meaningful conclusion can be drawn, such as with ‘aloe vera’ and ‘ginseng.’ 

(1) Zhonghua Bencao Editiorial Committee, Chinese State Administration of TCM, Eds.  Zhonghua Bencao (The Chinese Herbal), 10 Vols. Shanghai Scientific and Technical Press, Shanghai, 1999;  (2) Institute of Chinese Materia Medica, Chinese Academy of TCM, Eds.  Quanguo Zhongcaoyao Mingjian, 3 Vols.  People’s Health Publishers, Beijing.  1996.

 

 

Toxicity of Chinese medicines

         There are no uniform methods of assessing the toxic effects of herbs.  Modern scientific techniques may involve acute and subacute testing which have been devised for modern chemical drugs, and are thus not readily applicable to multi-component systems like herbs and foods.  Hence it is extremely difficult to predict the adverse effects of herbs based simply on such evaluation of a toxic chemical present in these herbs.  Yet such simplistic assessments are often used to define the toxic effects of herbal drugs.  Many of the recorded adverse reactions so far attributed to herbs in the modern literature have been equivocal, due to problems inherent in current herb education and research.  These problems include dubious identity of subject herbs, misappropriation of a single chemical for the total activity of an herb, and the bias of conventional medical and pharmacological researchers who undertake the studies or report on the findings.  The most notorious yet well-publicized and widely quoted ‘adverse effects’ of ‘ginseng’ is the classic report by Siegel, which coined the term ‘ginseng abuse syndrome.’3  It is a typical example of how the use of dubious test materials combined with ignorance about herbs and bias against herbs among conventional health-care professionals have produced and perpetuated a set of adverse reactions that I can best (and most charitably) describe as ‘misplaced.’ 

The continuous documentation of Chinese herbs, including toxic ones, has no parallel in other cultures.  It is a dynamic process that keeps updating and revising the record whenever new data arise.  Practically all toxicity data in Chinese herbal medicine are based on actual human experience over generations or centuries.  The highly toxic nature of certain traditional drugs was already documented about 3,000 years ago.  Thus, the Wu Shi Er Bing Fang (Prescriptions for Fifty-two Diseases), the first Chinese medical text, compiled sometime between 1067 BC and 771 BC, describes more than one hundred toxic drugs (including herbal, mineral, and animal drugs) among which are wu tou (aconite), ban xia (Pinellia ternata root), and li lu (Veratrum nigrum root/rhizome), many of which are also provided with processing methods to reduce their toxicity.  Then around 100 BC to 100 AD, the Shennong Herbal, the first book devoted exclusively to traditional drugs (365), groups them into 3 categories: superior (nontoxic), medium (potentially toxic, depending on use), and inferior (toxic).  However, even though inferior drugs (125) were considered toxic by classification, only 12 drugs were actually described as toxic with use precautions and contraindications.  In addition, certain toxic drugs like realgar (arsenic disulfide) are described as nontoxic and suitable for long-term use in the same herbal.  In another, later, classic herbal, Li Shizhen’s Ben Cao Gang Mu, published around 1590 AD, 381 among its 1892 drugs are clearly described as toxic.  In one of the most extensive modern records, the Zhong Yao Da Ci Dian, published in 1977, 495 of its 5767 drugs are reported as toxic.  In the newly published The Chinese Herbal described above, which contains monographs on 8,980 drugs, the number of toxic drugs is not immediately apparent.  However, in the Du Yao Ben Cao (Toxic Drugs Herbal), a book that specifically deals with toxic traditional Chinese drugs published in 1993, 903 toxic drugs are described in detail.4  And according to its editors, 55 of these toxic drugs were previously considered nontoxic in historical records. 

There is much latitude in the determination of which Chinese medicine is toxic and how severely so.  Traditionally, toxic drugs are classified into 3 categories: highly toxic, toxic, and slightly toxic.  Depending on the authors and the periods in which the herbals were published, drugs considered ‘highly toxic’ by one author in a particular period might be considered only ‘toxic’ by another.  And certain drugs considered ‘nontoxic’ might later be described as ‘slightly toxic.’  For example, in the Chinese Pharmacopoeia, mylabris (Chinese cantharides) was changed from ‘toxic’ in the 1963 edition to ‘highly toxic’ in later editions (1977-1995), ginkgo seed from ‘slightly toxic’ in 1963 and 1977 editions to ‘toxic’ in the 1985-1995 editions, herb-paris rhizome (chong lou) from ‘nontoxic’ in the 1977 edition to ‘slightly toxic’ in 1985-1995 editions, orostachys herb (wa song) from ‘highly toxic’ in the 1963 edition to ‘nontoxic’ in the 1977 edition, honeycomb (feng fang) from ‘toxic’ in 1963 to ‘slightly toxic’ in 1977 and finally to ‘nontoxic’ in 1985-1995 editions, houttuynia herb (yu xing cao) from ‘slightly toxic’ in 1963 to ‘nontoxic’ in 1977-1995 editions, and omphalia (lei wan) from ‘slightly toxic’ in 1963 to ‘nontoxic’ in 1977-1995 editions.  So the dynamic process of documentation continues.  What are recorded as toxic drugs only appy to those that have been found over time to be consistently toxic, though in different degrees, when used in the traditional manner.  There are countless others that ordinarily are not toxic but may be toxic if used outside of tradition.  These are the ones that are being increasingly held to produce adverse effects in recent years.  This trend has led to the misguided assumption by health professionals that the toxicity or adverse effects of herbal drugs are not known (despite the fact that they are well documented, at least in the Chinese literature) and hence should be treated in the same way as their modern synthetic counterparts.  These professionals have failed to distinguish between traditional herbal drugs and the new chemical drugs (single- or multiple-component) isolated or derived from them (e.g., orange peel vs synephrine, or Chinese ginseng vs ginsenosides).  The former have a long history of traditional use, while the latter are basically new drugs, despite their being derived from herbs.  Still, unlike their synthetic counterparts, these new natural drugs have been in the human system for millennia, albeit in much smaller amounts.  While documentation of the safety and adverse effects of herbs used in the West and those used in various ethnobotanical systems may be scanty, that of traditional Chinese drugs has been extensive and continuous since around 1,000 BC.  In fact, few of the more commonly used ones (plant, animal, and mineral) lack toxicity or safety records, or cautions and contraindications for their use.  Practitioners of TCM are taught to use toxic drugs that play an important role in TCM practice.  In fact, traditional physicians who are skilled in the use of toxic medicines to treat illnesses are highly revered.  Thus, highly toxic traditional drugs such as Sichuan aconite (both the main root called chuan wu, and the cured lateral root called fu zi), chan su (toad venom), and minerals containing arsenic (e.g., realgar or xiong huang), mercury (e.g., mercuric sulfide or zhu sha), and lead (e.g., lead tetroxide or qian dan) are still routinely used by TCM physicians.  Poisoning or adverse effects due to Chinese herbs are usually caused by ignorance and/or their inappropriate use.  Because of the laxity in adhering to truly traditional Chinese medical principles in training modern-day TCM physicians5 and the misconception of ‘modernized’ TCM (Issue 21, p. 2), such adverse events are bound to increase rapidly in the near future, further spurred by a misinformed public who frequently use these medicines as dietary supplements, and outside of traditional practice.

(3) R.K. Siegel, “Ginseng abuse syndrome,” JAMA, 241, 1614-1615(1979); (4) C.L. Yang et al., Eds. Toxic Drugs Herbal.  Chinese Medicine and Materia Medica Press, Beijing, 1993, 1119 pages;  (5) H. Fruehauf, “Science, politics, and the making of ‘TCM’ – Chinese medicine in crisis,” Journal of Chinese Medicine, No. 61, October: 6-14 (1999).