Number 23
November/December 1999

Herbs in this issue:

American ginseng

Gotu kola





A Note From Dr. Leung


More worthless herb research?!


    The herbal supplements business is exploding; so is information relating to herbs!  The general public is confused.  And I am getting more and more skeptical.  How much information on herbs and herb research currently available from various databases and print media is actually worthless?  My conservative estimate is no less than one-third. 

     I have written about this earlier and provided a set of guidelines/criteria for researchers, journal editors, and abstractors to assure that they don’t miss the point and waste their research efforts (Issue 17, pp. 1-2; Issue 18, pp. 1-2; Issue 19, pp. 2-3).  We have been so used to dealing with research and clinical trials on drugs (well-defined chemical entities) that frequently we forget that botanicals are very different and not to treat them as pure chemicals.  Yet many of us do treat them as if they were pure chemical drugs.  This negligence (or ignorance) often leads to meaningless results.


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.


        Here are 2 more publications that have recently come to my attention.  One is on “American ginseng” [Am. J. Chinese Med., 26(1): 47-55(1998)] and the other on Centella asiatica or gotu kola [Indian J. Psychiat. 19(4): 54-59(1977)]. 

        The first report is titled “Gut and Brain Effects of American Ginseng Root on Brainstem Neuronal Activities in Rats.”  It’s a “brainy” subject about which I profess to know little.  However, I know one very important thing.  If the natural product used by researchers in their study is not correctly identified and characterized, the results of their study will either be misleading or worthless.  If one does not know, or is not sure of, the identity of the herbal material one intends to study, it is better not to study it at all.  In this case, the investigators write under Materials and Methods:  Panax quinquefolium L. was purchased from Roland Ginseng LLC (WI).  Chinese-cultivated Panax quinquefolium L. was purchased from a store in Chicago’s Chinatown, marked as “American ginseng root, made in China.”  There was no effort or record in correctly identifying the two ginseng samples, either by physical or chemical means.  The American ginseng sample purchased from a Wisconsin company (Roland Ginseng LLC) was probably genuine American ginseng.  If necessary, one can probably verify its identity with the supplier.  However, for a scientific publication, this is not good enough.  The authors as authorities in the subject should leave no doubt about what they were studying.  Ginseng is not a chemical like pure ascorbic acid or acetylsalicylic acid (aspirin), which is the same, no matter where you purchase it, and which can be easily identified.  American ginseng, on the other hand, comes in different forms.  An untrained person (including scientist) will not be able to differentiate it from Asian ginseng.  Yet, in this publication, the authors totally relied on a Chinatown store’s label of “American ginseng root, made in China” as proof of the herb’s identity.  It is a fact that some Asian ginseng is passed off as Chinese-cultivated American ginseng.  Consequently, the authors might well have studied and compared the following:  American ginseng with Asian ginseng, 2 grades of Asian ginseng, or 2 grades of Chinese-cultivated American ginseng.  But which one?  No one knows because the authors never bothered to verify what they were studying.  Just imagine having spent all this time and money in coming up with these findings!  Untrained scientists and researchers as well as lay writers will be disseminating this misinformation, thus further confusing the field of herb research.  In this particular case, it is indeed a pity, because the authors did seem to understand the traditional use of ginseng, as evidenced by their using a hot-water extract (and not a cold water infusion, for example) in their studies. 

        The second report is an old paper titled “The Effect of Centella Asiatica on the General Mental Ability of Mentally Retarded Children.”  In this paper, the authors seem to have done a rather thorough review of the literature and pointed out the inadequacies of previous studies.  Thus, I quote, “In general, these studies are ambiguous.  Whereas some studies have shown a positive therapeutic effect, subsequent studies have not stood the scrutiny.  Many of these studies (Louttit, 1964-65) lack controls thus precluding the advantages of double blind trials.”  It is obvious that the authors are very proud of their experimental design (placebo, double blind, etc.).  However, despite the care and efforts that have gone into the preparation of their investigations, they neglected to tell us what exactly they were studying.  I searched for clues to what they were actually using as “Centella asiatica,” but all I could find was this, “The children were given one tablet (0.5 gm.) a day for 6 months.  Placebo tablets were made of starch and suitably coloured to match the drug.”  What was this “tablet (0.5 gm.)?”  Was it made of powdered herb, a powdered extract with hot water, a powdered extract with pure ethanol, or a mixture of pure Centella glycosides such as brahmoside and brahminoside?  It certainly could be any one of the four, and maybe more.  A research finding is only valid when someone else independently duplicates it.  Without knowing what these authors were actually studying, can anyone truly duplicate and validate their results?

        Again, it is clear that, in order to assure the identity of the materials being studied, we sorely need formally established procedures for research scientists, editors, writers, abstractors and anyone else involved in natural products to follow.  These need to be established soon, so as to stem the continued flood of misleading and worthless data into existing databases.  The criteria I have previously outlined can serve as a start [Issue 19, pp. 2-3].


Attention-Deficit/Hyperactivity Disorder (ADHD) children

        I often wonder if great minds like Albert Einstein and Thomas Edison would have made their great contributions to humanity if they were born and raised in our current stressful and drug-oriented society.  When they were young school children, Edison was “bottom of class” while Einstein was considered “mentally slow.”  Were they suffering from ADHD?  And what might have happened had they been given ritalin or a related drug to turn them into “normal” and good students?  They would then have paid attention in class.  Their school psychologists and teachers would probably have been happy.  But would Einstein have become Einstein and Edison, Edison?  The answer is academic.  But the fact is that we hadn’t discovered ADHD at their time and there were no drugs to change children’s mind and behavior.  And thank goodness for that!

        In our current American society, if you are a “mainstream” student, our school system seems fine.  However, if you didn’t fit the mold, you would most likely be labeled and even stigmatized.  I know because of personal experience with both non-American and American education systems. 

        This is sort of a confession.  I am doing this because my children are grown and there is no need to pretend I was a mainstream student.  Also, I feel my story may offer a “second opinion” to parents with “mentally slow” or “disruptive” children.  By the way, my wife at times threatens to petition my alma mater, the University of Michigan, to have my Ph.D. “recalled” because, according to her, I am often so “dense.” 

        I have never been diagnosed as suffering from ADHD, but my family, friends, and close business associates know I have a very short attention span and am sometimes mentally slow.  While growing up in Hong Kong, I went through first the Chinese and then the British education system.  I did very well in subjects that I liked but so-so in those I didn’t like.  Since I did fairly well overall at school, I was allowed to play a lot as a child.  Then at around age 10, I was thrown out of school, because according to my family, the priest in charge at that school said I was not paying attention in class (probably some really boring subject) and was disturbing other children by talking to them.  After that, I spent a couple of years in another school, but all I remember about that one is that it was half way up the hill, a very nice environment.  A few of my classmates and I used to go up the hill to have stone-throwing “battles” until one of my friends got a bloody skull; then we stopped.  Now I cringe even at the thought of kids doing that.  I don’t remember what happened next except that I was having private English lessons given by an older girl who was going to English school.  Soon after that I went to the English section of the same school from which I had been expelled.  I did exceptionally well until 2 years before graduating from that high school, when my family had some serious financial troubles.  I guess I was not paying attention to some subjects that I found boring, such as Chinese recitation (memorizing classics) and Chinese history, and I flunked enough of them to be expelled, again.  However, I was tops in all the “important” subjects (English, math, physics, chemistry, biology, geography, etc.), so I went to another school, skipped a grade, and graduated a year earlier than my former classmates, passing the school certificate examinations with honors.  These exams were taken by all high-school students.  You only needed to pass 5 subjects.  If you didn’t pass, you basically were not considered a high school graduate.  Now looking back, I could have used a little more direction.  I could have used a teacher or mentor who could interest me in the Chinese classics.  But I am grateful that my family had been understanding and let me be myself.  I can’t imagine what I would have turned out to be if I had grown up here under the current environment and given drugs to make me “focus.” 

        My older daughter, Amy, is very much like me.  She is a cellist with the Coolidge Quartet, which she co-founded 5 years ago in Poland.  Her Quartet is currently in residence at the University of Maryland under the mentorship of the Guarneri Quartet.  Like me, Amy was not a bad student but sometimes “out in space.”  She excelled in subjects she liked but only “managed” in subjects in which she had little interest.  I remember when she was perhaps 7 or 8.  One time she came home from school rather upset, telling my wife that the teacher was not fair because she did the spelling correctly for “tern” but she got penalized for giving the wrong answer.  It turned out that she was not paying attention to the teacher’s assigned list of words, which she was supposed to have memorized.  So, when the teacher wanted the class to spell “turn” Amy was thinking of the bird, tern, which she learned by studying nature books (not part of the school curriculum).  My wife, herself an A-student, had expected Amy to be like her in the beginning,  But she soon realized we had a very different, but creative, child on our hands who marched to her own drummer.  In short, Amy was not easy to raise.  But we have done our job to the best of our financial and intellectual abilities. 

        I often wonder what would have happened to Amy and me if we had been entrusted to the hands of modern educators and teachers who are often so eager to label absent-minded or overly active children “ADHD kids” and try to “help” them with counseling and drugs.1  Is student control a necessity in the modern classroom environment?  Or is it just a matter of placing students in neat categories to make the teachers’ job easier?  Or has it been a marketing coup for some pharmaceutical executives to “hook” our kids on ritalin and other behavior-altering drugs?  It is a tough situation and there is probably some truth in all these.  Not being an educator of school children, I am glad I can take the easy way out by not dealing with it and leaving it to the “experts.”  But are these “experts” taking the easy way out?  Or is the drug culture in our society so entrenched in recent years that these “experts” have become its spokesmen and executives?  Only time will tell.

(1) J.E. Brody, “Diet Change May Avert Need for Ritalin,” The New York Times, Nov. 2, 1999, D8.


Licorice as “mitigator”of harsh drugs

        Chinese drugs are normally used in combinations, and licorice is the single most used drug in Chinese formulas.  Its 2 major functions are: (1) to mitigate the potential toxic side effects of other herbs in the formula, and (2) to enhance the therapeutic effects of other herbs, especially the main one(s).  These 2 are basically also the reasons why combinations are used in traditional Chinese medicine.  Because of these functions, licorice in Chinese is also known as guo lao, which means “national elder” or “elder statesman,” because an elder statesman can bring harmony among different political factions, just as licorice can harmonize the functions of different herbs.  Over the past few years I have observed numerous incidences of scientific substantiation of these traditional usages.  Here is a recent publication on licorice research that provides a justification for the use of licorice to mitigate the toxic side effects of other herbs.

        Determination of Flavonoids in Decoctions of Licorice Root and Combination of Licorice Root and Prepared Aconite Lateral Root [Zhongchengyao, 21(4): 196-198(1999)].  Licorice root is traditionally considered to be anti-toxic (detoxicant).  In modern scientific studies, Chinese researchers have demonstrated its total flavonoids to have anti-ulcer, anti-inflammatory, antispasmodic, antimicrobial, analgesic, and anti-arrhythmic activities.  In a previous report from the same institution (Nanjing University of TCM), total licorice root flavonoids were shown to significantly inhibit the arrhythmia induced by aconitine and chloroform in mice and ouabain in guinea pigs, in a dose-dependent manner.2  This anti-arrhythmic effect of licorice flavonoids can be considered a modern verification of licorice root’s traditional anti-toxic properties.  In the present paper, the effects of combining licorice with a toxic herbal drug, fuzi (prepared aconite lateral root), are reported.  The licorice used in this study contained 2.23% total flavonoids (based on liquiritigenin and isoliquiritigenin).  When decocted (boiled with water) alone, the amount of total flavonoids extracted was 1.18% (52.9% removal).  But when decocted in combination with fuzi, as is typical in traditional usage, the amount of total licorice flavonoids extracted from the licorice was 1.85% (or 83.0% efficiency), much higher than when it was decocted alone.  It is obvious that something in fuzi facilitates the solubilization of flavonoids from the licorice.  This provides a rationale for using licorice as a mitigator of the toxic effects of fuzi.  Thus, not only is licorice itself well known for its traditional anti-toxic property, this effect is enhanced when it is used in formulations, as evidenced by the increased extraction efficiency of its anti-arrhythmic flavonoids.  Its anti-toxic effect against fuzi was already documented 2,000 years ago in the Shang Han Lun, a traditional Chinese medical treatise on febrile diseases.  In this work, among the 17 prescriptions that contain fuzi, 9 also contain licorice, often in relatively large amounts.  The decision behind the use of licorice to mitigate the harshness (toxicity) of fuzi was reached in ancient times, not by modern chemical or pharmacological analyses but, rather, through the empirical science of trial and error as well as observation and documentation. 

(2) X.Y. Hu et al., “Anti-arrhythmic Effects of Total Flavonoids of Licorice,” Zhongcaoyao, 27(12): 733-735(1996);  Leung, A.Y., and S. Foster, Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics, Wiley-Interscience, New York, 1995, pp. 346-350.


More on Astragalus

       Astragalus is the root of Astragalus membranaceus and A. mongholicus as well as other Astragalus species.  Despite specific labeling, few astragalus products sold on this continent or elsewhere can be traced to the particular species labeled.  Which is not new, as TCM uses the roots of these Astragalus species interchangeably.  This makes labeling anything more precise than the plant genus of little practical value and is used basically to appease the “scientific” minded or federal regulators who are accustomed to dealing with single-chemical drugs.  To them, even a well-defined plant species is already a little difficult to accept, let alone a genus that may include one of several species.  Hence those involved in writing specifications or monographs of Chinese herbs either are of the same mentality or simply adopt it to make things easier for all, even though they are well aware of the impracticability of specifying a particular plant source in many commercial products.  On the contrary, herb labeling in commercial products has been quite different in China.  For example, astragalus in China is simply labeled as huang qi in Chinese, sometimes accompanied by its Latin pharmaceutical name, radix astragali, which we all understand to be the root from 1 of at least 2 related plants.  However, things are changing.  In order to comply with US regulations, some Chinese manufacturers and suppliers are starting to label herbs with Latin binomials.  While this is great for simplistic justification and documentation purposes, it is often inaccurate or at best, misleading, as in the case with astragalus.  The fact is this.  In commerce, there is no way to tell the source of astragalus in a product, no matter how it is labeled.  One can only be reasonably sure that it is either from A. membranaceus or A. mongholicus

        I have written about astragalus in most previous issues of this Newsletter as well as in my books.  The beneficial biological activities of astragalus (as powdered herb, decoction, and various extractives) have been well documented.  They include the following activities:  immunostimulant, antiviral, antioxidant, cardiovascular, memory improving, antifatigue, etc.  However, when we make these statements, we frequently forget to clarify and specify what form(s) of astragalus exhibits these activities.  Is it the decoction, the powdered root or some highly purified chemical fraction (e.g., saponins, polysaccharides)[See Issue 19, pp. 2-3 for criteria for evaluating herb research]?  We often use “astragalus” as if it were a well-defined chemical entity, but in fact, it is not.  When I see the word “astragalus” without any qualifier, I would take it, though without certainly, to mean huang qi (astragalus root) normally used as a powder, decoction or total alcoholic extract.  It definitely should not be used to describe a specific “injectable liquid” or a saponin or flavonoid fraction.  Yet this is often the case, even in so-called “professional reviews” intended for health practitioners. 

        I have just read such a “Professional Review” on astragalus by MediHerb (#67, February, 1999), published in Australia.  The word “astragalus” without qualifier was used more than 2 dozen times in this 4-page review.  A few of these, when used in the traditional context, seem clear enough. However, when I looked up a few of the original references quoted, I discovered that many instances of the “astragalus” used were for describing modern findings.  Some of them represented undisclosed proprietary preparations (including combinations) and modern “injectables” or “oral liquids” containing astragalus.  It appears that the authors might have based their information primarily on abstracts from the National Library of Medicine.  The reason is that, as far as I know, only the Library of Congress, the NLM and Taiwanese institutions still use the archaic Wade-Giles transliteration system, which predominates in the literature cited in this review.  Hence, it is highly probable that the authors never saw the original references and would not know what was actually being used in the studies reported.  They had two strikes against them:  (1) Chances are that the original reports never clearly identified the nature of the herbs used in the study; and (2) Even if the herbal materials used in the studies were clearly identified in the reports, chances are that NLM abstractors, who are not trained in the intricacies of natural products, did not recognize the importance of specificity and failed to carry it over into the abstracts.  The result is that more useless or ambiguous information is generated, cluttering the NLM database, which is spread like a virus to other databases and print media. 

Leung, A.Y., and S. Foster, Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics, Wiley-Interscience, New York, 1995, pp. 50-53.