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— updated 1999-12-02

Herbalist Review, Issue 2000 #3: TCM paradigm and western herbs: Oregon Grape root as example

by Roger W. Wicke, Ph.D.

The traditional Chinese herbal protocol for assessing one's patterns of symptoms and signs and choosing herbs and formulas appropriate for this assessment can be used to better understand the effects of all herbs and even foods, not just 'Chinese' herbs.

Subtopics on this page…


Introduction

The paradigm of clinical TCM (traditional Chinese medicine) can help us understand the effects of all herbal preparations, not just herbs listed in the official Chinese materia medica. Frequently, RMHI staff and students are asked about a particular herb (Saw Palmetto, Calendula, Echinacea, Oregon Grape Root, etc.) and how to apply it. However, to do this well requires us to read between the lines of information commonly available in western herbal and medical literature.

Why most people rarely ask the right questions about herbs

The western herbal and medical traditions have placed a heavy emphasis on understanding the physiological actions of drugs and herbs in the body, and while this is useful information, stopping there leaves us with many gaps in our knowledge for one simple reason: most clients or patients will describe their symptoms to us, and we will have no idea (only guesses) about their blood chemistry, hormone levels, brain-wave characteristics, etc. Some of these tests are expensive, and, moreover, it is common for people with health complaints to have their medical lab results reveal no abnormalities. Experienced physicians and health care professionals eventually learn to go by their "instincts", which means learning by experience to interpret the individual's reported symptoms, behaviors, physical appearance, smell and any other unusual characteristics.

It makes no sense to interpose an extra layer of uncertainty into the clinical decision process, yet that is exactly what happens when strategies for regaining health are chosen based upon their presumed physiological effects. For example, suppose a woman has been experiencing premenstrual complaints of fatigue, irritability, constipation alternating with diarrhea, abdominal bloating and excessive menstrual cramping. While it is well known that FSH, LH, estrogen and progesterone are directly involved in regulating the menstrual cycle, adrenal and thyroid hormones may also be implicated in the listed symptoms, as well as abnormal gut flora and inadequate digestive enzyme secretion. In short, without measuring all these parameters over a monthly cycle (which would be extremely expensive), we can only speculate about what they might be. However, we do know what the symptoms are; there is very little doubt here. Therefore, it would seem to make sense to base a clinical strategy primarily on the symptoms and other easily observable clinical signs; to do otherwise would introduce an added layer of uncertainty. It is sheer folly to choose herbs based upon physiological actions that may or may not be appropriate, because without extensive lab testing we are merely speculating, and our probability of making erroneous conclusions increases.

A serious problem arises in clinical decision making, however, when our information about an herb or drug consists primarily of physiological actions with very little discussion of its effect on symptoms and symptom patterns, because improvement of symptoms or appearance of side-effects are often the sole criteria for deciding whether or not to continue taking it. Often, the only clues we may gather regarding effects on symptoms is contained in the fine print under "contraindications" and "possible side-effects". (These ideas are explored in detail in chapter 2 of TCHS Volume 1.)

The remainder of this report will outline the procedure that one should follow in reconstructing a tentative description of the actions of an herb not listed in the TCM materia medica, but for which information is available in the western literature. In short, I will give you some guidelines for "reading between the lines".

Checklist of properties and specifications we need to determine

Often when we consider the use of an herb, we already have information about it from sources ranging from ethnobotanical (folk medicine) to physiological/pharmacological. Before any herb can be used safely and reliably, the following categories of information need to be determined:

  • botanical identity, portion of plant or organism used
  • preparation method and recommended dosage
  • toxicity
  • taste and thermal qualities (hot/cold), as classified in the TCM paradigm
  • TCM syndrome indications (for which symptom-sign patterns are the herb indicated?)
  • contraindications, TCM as well as physiological

Botanical identity, preparation, dosage

Before determining appropriate clinical usage, assuring standard criteria for botanical identity (genus and species) and preparation are essential. In collection information from various sources and integrating this information, we need to be certain that all the information refers to a consistent preparation. Common names for plants are frequently unacceptable in identification, as they are too variable and uncertain. Preparation includes such aspects as harvesting, slicing, drying, and any special extraction or chemical processing. Certain plants may require special preparation to enhance desired properties or to reduce toxicity. Others may require growing in certain types of soil, specific cultivation methods, or harvesting at only certain times of year to ensure desired properties.

Recommended dosages will be dependent upon the particular method of preparation. One should verify that the dosages specified among various sources are consistent. If the dosage is specified in other than dry weight of the whole herb, the method of processing or extraction is crucial to determine the concentration of the final product.

Toxicity

Ethnobotanical literature documenting historical usage, clinical testing, and pharmacological toxicity testing are all useful sources of information regarding toxicity. It has been assumed, with good reason, that herbs and foods in common usage for several centuries or longer would be unlikely to have significant toxicity, or such effects would have become common knowledge. Long-term toxicity, which is occasionally difficult to detect or verify even with pharmacological screening (e.g., the Ames test for mutagens •[1a]• •[1b]• •[1c]• does not always detect carcinogens), does tend to show up with long-term historical use upon careful observation of human cultural groups. The rationale and methods are similar to those underlying studies correlating high-salt diets to incidence of stomach cancer in Japan, for example. •[2a]• •[2b]•

Herbs not in common usage, but for which historical reports exist of their use, are more problematical. In these cases, an understanding of the history of the period from which the report originated is crucial to determining its likely accuracy and authority. For example, much of European literature on herbal medicine originated during a time of periodic persecution of herbalists ("witches") and midwives. •[3]• The Middle Ages of Europe, while harboring pockets of learning and erudition, were a time of conflict and warfare, which frequently impinged upon religious, philosophical and scientific matters. "Witches" were often interrogated under torture for their herbal knowledge, especially regarding herbs used for contraception, abortion, and conception. •[4]• Herbal knowledge compiled during this period should be examined with great skepticism, as its authors were often afflicted with superstitious and irrational influences.

Species of the plant genus Senecio, for example, are now known to contain toxic pyrrolizidine alkaloids that can induce liver cancer in a high proportion of animals fed this plant. •[5]• Yet this herb has been mentioned in recently published texts of herbology as useful for menstrual cramps, based on historical references from the Middle Ages! Fortunately, Senecio is not in common usage in recent history, and for good reason.

The pharmacological basis of action of herbs, while providing only an incomplete basis for choosing herbs clinically, has nevertheless provided useful information in understanding the toxicity of herbs containing well studied phytochemicals. Examples of this include the solanaceous plants Belladonna and Hyoscyamus (atropine, hyoscyamine, scopolamine), Ephedra (ephedrine), Rauwolfia (reserpine), and Digitalis or foxglove (digitalis). •[6]•

Taste and thermal qualities (hot/cold)

Once an herb has been determined to be safe after proper identification and screening for toxicity, its taste and thermal nature ("hot"/"cold") should be determined by simple taste testing, preferably by a group of people with a known range of constitutional characteristics and body types (or symptom-pattern tendencies, in TCM) so that any variation in reactions can be correlated with their predispositions.

The TCM system of classifying herbs place a great importance on taste and thermal nature. While these qualities are considered to be of minor significance in western allopathy and given little scientific priority, this is puzzling given that the senses of taste and smell are the most important early-warning defense system that the body uses to prevent one from consuming deadly and poisonous plants. Rotten and spoiled food, likewise, exudes numerous chemical signals that cause instinctive revulsion and sometimes vomiting. Appetite and cravings normally act to stimulate consumption of necessary nutrients, and the taste and smell of foods will trigger physiological reflexes that result in secretion of necessary salivary, gastric, and pancreatic enzymes. •[7]• The various types of taste buds on the tongue surface are capable of detecting minute concentrations of sugars (sweet), salts and electrolytes (salty), acids (sour), alkaloids (bitter), and other chemical components of food and herbs. •[8]•

It should, therefore, be expected that any rational system of clinical herbology would include taste as an important criterion in classifying herbal properties. Lacking the funds to build an expensive phytochemistry lab, we would be wise to make use of the sensitive chemical analyzers that nature has provided to us at no expense.

Regarding hot and cold, these ideas are discussed in Chapter 2 of TCHS Volume 1. As examples, black and chili peppers are very hot, cinnamon is warm, milk of magnesia is very cold, and herbs like goldenseal and coptis are cold. •[9]• Hot herbs generally have a stimulating action on the metabolic rate, increasing a sense of warmth; some are circulatory stimulants. Cold herbs generally will have a depressive effective on the appetite and digestion; that many antibiotics are bitter and tend to destroy normal gut flora necessary for assimilation and digestion correlates with the TCM classification of these herbs as being cold and possibly damaging to the normal or "righteous Stomach Fire". Most people will be able to instinctively classify herbs as hot, warm, neutral, cool, or cold based on the sensation of the herb in their mouth and later as it enters the stomach. (Ayurvedic herbology further differentiates these qualities into pre- and post-digestive effects, which may be different. •[10]•)

In the next section we will discover how these simple taste and thermal classifications (based on TCM clinical theory) will provide insights for translating physiological information from western herbal literature into the more clinically useful language of symptom-sign patterns.

TCM clinical functions

Rather than describe the physiological actions of an herb (and force one to guess what ultimate effect this will have on the client's symptoms), the TCM functions specify the patterns of symptoms and signs that are likely to be relieved by taking it. Note that this means we do not choose herbs based upon some speculated physiological phenomenon that may or may not be occurring, nor do we choose herbs based on single symptoms, as many people do when they go to a health food store (what herb will help relieve my headache, stomach pain, etc.?) The totality of the symptoms and physically observable signs (complexion, behavior, posture and gait, voice and speech quality, etc.), as a pattern, comes closest to giving us a set of clues, when considered together, that will maximize our likelihood of eliminating herbs that may result in side-effects and of choosing herbs most likely to be appropriate for the totality of symptoms and signs presented by the individual at the moment.

The symptom-sign patterns of TCM require much study to learn, recognize, and differentiate; all I can do here is to state the basic principle.

Contraindications

Contraindications in the TCM system are almost a reverse image of the clinical functions and are also defined in terms of patterns of symptoms and clinical signs for which an herb should be avoided or used cautiously. Single symptoms are rarely listed as contraindications because they are not specific or circumscribed enough. The best way to explain this is by example, as in the case of Oregon Grape Root outlined below.

Example: Oregon Grape (Mahonia)

To illustrate how one would apply the preceding guidelines to arrive at a working clinical description of an herb not classified by the TCM materia medica, let's examine the potential clinical uses of the herb commonly know as Oregon Grape (Mahonia repens, or according to some botanists, Berberis repens) Root, which is a plant that grows in coniferous forests throughout the mountainous western U.S. •[11a]• •[11b]• for botanical identification.

Preparation •[12]• •[13]•: The roots and main stems may be harvested at any time of the year. "Put l-2 teaspoonfuls of the root in a cup of water, bring to boil and simmer for l0-l5 minutes. This should be drunk three times a day." (This would be equivalent to about 3-6 grams of dried herb per day.) Other sources •[13]• •[14]• indicate similar equivalent dosage ranges.

Toxicity: Information from Hoffman •[12]•, Moore •[13]•, the Alternative Medicine Foundation HerbMed Database •[15]•, and other sources •[16]• •[14]• make no mention of any significant toxicity. Furthermore, data documenting use by American Indian tribes of the western U.S. reveal that Oregon Grape has been used widely for conditions very similar to those listed by Hoffman, and that no significant toxic effects were mentioned. •[17]•

Indications according to western herbal sources

According to Michael Moore •[13]•, this herb is said to be very similar to barberry (Berberis fremontii, B. fendlerii), which is antipyretic, anti-inflammatory, laxative, antibacterial, and acts as a liver stimulant, "blood purifier", and intestinal strengthener. Is it also mentioned as being useful in lowering bilirubin levels in cases of hepatitis. Mahonia is said to be somewhat more effective than barberry for liver problems.

David Hoffman •[12]• lists the applications and indications of Oregon Grape as including chronic and scaly skin conditions such as psoriasis and eczema; stomach and gall-bladder conditions, especially where there is associated nausea and vomiting; chronic constipation.

Hoffman also lists indications according to Priest and Priest: "catarrhal disorders of stomach, intestines and urinary organs. Hepatic torpor, bilious headache, eczema, herpes, psoriasis, acne, facial blotches and pimples." Indications listed by Ellingwood include "scaly, pustular and other skin disease due to the disordered conditions of the blood; ...pimples, roughness, eczema capitis, eczema genitalis, pruritis, scaly eczema, psoriasis, pityriasis, chronic dermatosis, glandular indurations, ulcerations, syphilis."

Supporting research

Many of the clinical uses suggested by Moore and Hoffman are supported by scientific studies of Mahonia and closely related species and by studies of known chemical constituents and their physiological activity. These constituents include a family of compounds known as isoquinoline alkaloids, including berbamine, berberine, canadine, columbamine, corydine, corypalmine, corytuberine, hydrastine, isoboldine, isocorydine, jatrorrhizine, magnoflorine, mahonine, oxyacanthine, palmatine, tetrahydroberberine, tetrahydrojatrorrhizine; other constituents include resin and tannin. •[16]•

The chemical constituent thought to be the most important clinically is berberine •[15]• •[16]•, which has been shown to have antibiotic activity against Mycobacterium tuberculosis, Bacillus subtilis, Salmonella enteritidis, E. coli, and various fungi. (Berberine is responsible for giving herbs containing it a characteristic bright yellowish color.) It also inhibits secretory responses to enterotoxins of Vibrio cholerae and E. coli in isolated intestine. Berberine, and to some extent oxyacanthine, suppress delayed type hypersensitivity reactions. Berbamine and oxyacanthine inhibit keratinocyte growth, which explains Oregon Grape's claimed usefulness in cases of psoriasis. •[15]• Other miscellaneous constituents have been shown to block the action potential of transitional pacemaker cells (7-O-demethylisothalicberine) and induce relaxation of aortic tension (berbamine, oxyacanthine). •[15]• •[16]•

TCM evaluation of Oregon Grape Root (Mahonia)

Now we need to sift through the preceding indications and research conclusions and combine this information with the TCM taste and thermal characteristics, to arrive at a description of the properties of Mahonia in terms of TCM-style patterns of symptoms and signs. This process is much like piecing the parts of a puzzle together, and organizing the pieces into logical groups may help us to better evaluate them. Our relevant evidence may be separated into several types:

  • (A) Similarities in botanical, phytochemical, and taste characteristics between Mahonia and specific herbs described in the official TCM materia medica;
  • (B) Groups of medical and single-symptom indications for Mahonia that, by themselves, suggest specific TCM symptom-sign patterns.
  • (C) Similarities in medical and single-symptom indications for Mahonia that are consistent with specific TCM symptom pattern indications for similar herbs determined in step (A).

First, let's consider evidence of type (A), above:

(A1) Mahonia is a purely bitter tasting herb with no secondary tastes (sweet, sour, salty, etc.), similar in quality of bitterness, but somewhat less intense, to the following Chinese herbs: Scutellaria baicalensis root (huang/ qin/), Coptis rhizome (C. chinensis, C. deltoidea, C. omeiensis, or C. teetoides; huang/ lian/), and Phellodendron bark (P. amurense or P. chinense; huang/ bai~). •[18]• All these herbs are classified as "cold" in the TCM system, and the implications of this will become clear when we analyze evidence of type (C) for classifying the TCM functions.

(A2) Several of the herbs mentioned in (A1), while very different botanically, share the feature of containing some of the same isoquinoline alkaloids as contained in Mahonia. Coptis (huang lian) contains berberine, columbamine, and palmatine; Phellodendron (huang/ bai~) contains berberine, jatrorrhizine, magnoflorine, and palmitine. •[18]•

(A3) While similarity of certain chemical constituents is no guarantee of similarity in clinical function of the whole herb, it is one of many factors that can suggest such a possibility. That the Chinese herbs Coptis and Phellodendron are similar both in phytochemistry and subjective taste to Mahonia is cause for further evaluation.

(A4) The broad-spectrum antibiotic activity of Mahonia (due to its constituent berberine) against Mycobacterium tuberculosis, Bacillus subtilis, Salmonella enteritidis, E. coli, and various fungi, and its inhibitory effects against endotoxins of E. coli and Vibrio cholerae are very similar to the antibiotic activity of Coptis and Phellodendron against Salmonella, Shigella, Mycobacterium tuberculosis, Pseudomonas, Streptococcus, and Staphylococcus. •[18]•

Now, let's consider evidence of type (B) for Mahonia:

(B1) The antibiotic activity described in (A4), together with the listed indication of "catarrhal [inflammation of the mucous membranes] disorders of stomach, intestines and urinary organs" strongly suggests that the primary function of Mahonia is to "Clear Damp Heat", which is also the primary function of the Chinese herbs Coptis and Phellodendron.

(B2) Damp Heat conditions are characterized by the presence of a majority of the following symptoms and signs: sticky, thick, and yellow or green mucous discharges; watery, oozing skin eruptions; tendency toward foul-smelling loose stools, or constipation alternating with diarrhea; nausea, reduced appetite, reduced thirst although may complain of dry mouth, abdominal fullness and distention; a ponderous heavy sensation of the body; torpor, fatigue; tongue coating yellow and greasy-wet; tongue tissue color reddish; complexion yellowish; radial pulse quality slippery and rapid. •[19]•

(B3) The TCM paradigm subdivides Damp Heat conditions according to which body functions are affected (these functions are often loosely translated as "Organs"). The western indications of "catarrhal [inflammation of the mucous membranes] disorders of stomach, intestines and urinary organs", plus "hepatic torpor, bilious headache, eczema, herpes, psoriasis, acne, facial blotches and pimples", suggests that the functional domains of Liver, Stomach, Intestines, and Urinary Bladder are the primary targets of Mahonia, as would be classified in the TCM system. In addition the "Lungs" should be considered for inclusion also since TCM theory considers many skin diseases to be within the domain of the Lungs.

  • Liver Damp Heat would include many of the symptoms and signs of Damp heat (B2) plus especially: bowstring-slippery pulse, subcostal pains and distention, jaundice, and nausea or vomiting.
  • Urinary Bladder Damp Heat would include (B2) plus especially: dark yellow urine, burning on urination, frequent urination with urgency.
  • Damp Heat of the Intestines would include (B2) plus especially pronounced diarrhea and foul-smelling stools, possibly with blood and mucus discharge, and a sense of urgency on defecation.
  • Damp Heat conditions of the skin would include (B2) plus: reddish, oozing skin rashes, eruptions, and discharges.

Finally, by considering evidence of type (C), we will strengthen many of the conclusions of type (B) by examining the TCM functions of Coptis and Phellodendron, which we already strongly suspect of being very similar to Mahonia in their clinical functions:

(C1) Coptis, according to the TCM materia medica •[18]•, clears Damp Heat, quells Fire Poison, clears Heart Fire, drains Stomach Fire, and clears Heat topically. Many of these terms refer to symptom-sign patterns very similar to Damp Heat, but with emphasis on specific symptoms. Fire Poison is a condition that manifests as reddish-colored rashes, boils, and abscesses; Stomach Fire is a condition of inflammation of the upper digestive tract with bad breath, belching, and a burning sensation of the esophagus; Heart Fire includes symptoms of insomnia, heart palpitations and manic behavior.

(C2) Phellodendron drains Damp Heat, especially of the Intestines and Urinary Bladder, and quells Fire Poison. •[18]•

(C3) By comparing the TCM functions of Coptis and Phellodendron with the evidence of type (B), we conclude that Coptis is more similar in function than Phellodendron to the functions of Mahonia repens. The special emphasis in the western sources on the use of Mahonia for liver conditions leads us to conclude that Mahonia is perhaps more focused on clearing Liver Damp Heat than is Coptis.

(C4) While no mention is made in the western sources of any use of Mahonia for insomnia or palpitations (of the Heart-Fire type), the interesting note that constituents of Mahonia have been shown to block the action potential of transitional pacemaker cells (7-O-demethylisothalicberine) and induce relaxation of aortic tension (berbamine, oxyacanthine) suggests that an unrecognized function of Mahonia is to clear Heart Fire, similar to Coptis.

(C5) To summarize all our evidence, we can now tentatively suggest that Mahonia would have the following TCM clinical functions:

  • Clears Damp Heat of Liver, Stomach, Intestines, and Urinary Bladder;
  • Quells Fire Poison;
  • Clears Heat topically (Heat and Damp-Heat type skin rashes);
  • Clears Heart Fire.

(C6) Furthermore, the TCM contraindications for both Coptis and Phellodendron, and most likely Mahonia repens also, include:

  • patterns of Deficiency of Yin (dehydration, thirst, irritability, thready-rapid pulse, reddish tongue color with fissuring, very thin or no tongue fur);
  • nausea or vomiting associated with Deficiency-Cold of the Stomach and Spleen (fatigue, loose stools, poor appetite, averse to cold weather and becomes easily chilled, pale complexion and tongue color, thin white tongue coating, weakened or soft pulse);
  • diarrhea from Deficiency of Spleen and Kidneys (similar to Deficiency-Cold of the Stomach and Spleen);
  • prolonged use is not advisable, as it may injure Spleen and Stomach.

How does the TCM description help us more selectively and effectively use Oregon Grape root?

In reviewing the indications from Hoffman, Moore, and other western herbalists, it becomes clear from the TCM description of Oregon Grape Root (C5) how to interpret many of the listed indications. For example, when it is said to be a useful laxative in cases of constipation, we now strongly suspect that it would not be useful in types of constipation associated with conditions of weak digestion, poor appetite, pale complexion, pale tongue, and fatigue ("Deficiency of Spleen and Stomach Qi"). In fact this type of condition is likely to be aggravated by Oregon Grape. Regarding its reputed quality as an "intestinal strengthener", we would be skeptical, as many conditions of weakened peristalsis accompany conditions of "Deficiency of Spleen Qi", for which herbs like Coptis and Phellodendron are contraindicated. For similar reasons, Coptis and Phellodendron are contraindicated in nausea and vomiting associated with "Deficiency Cold of the Spleen and Stomach". While Hoffman writes that Oregon Grape is useful in "stomach and gall-bladder conditions, especially where there is associated nausea and vomiting", this statement is too general, and the TCM functions and contraindications make this clear.

Another example of where caution must be exercised is in cases of chronic hepatitis (according to Hoffman: "liver stimulant... lowers bilirubin levels in cases of hepatitis") characterized by Deficiency of Liver Yin: jaundice, subcostal pains, irritability, insomnia, plus all the signs of Deficiency of Yin (C6, above). In fact, Oregon Grape should probably be contraindicated in any condition characterized by Deficiency of Yin, even though certain symptoms or conditions listed in the western indications may be present. Such contraindications may sometimes be overcome by combining with other herbs that counteract undesirable effects, but this subject is beyond the scope of this report.

Regarding the listed TCM contraindication of avoiding long-term use, note that the strong antibiotic actions of Mahonia, Coptis, and Phellodendron should remind us of the dangers of using any antibiotic for prolonged periods because of the damage to the intestinal flora that often results from such use. Normal intestinal flora is known to be essential to normal bowel function and absorption of nutrients, and this correlates with the statement by the ancient Chinese that bitter herbs may damage Spleen and Stomach.

Summary

The clinical indications for the use of many western herbs, including Oregon Grape Root, are often too general. By comparing data from phytochemical research, ethnobotanical (folk-medicine) records, historical usage, and TCM descriptions of similar herbs, we can systematically sift through the evidence to increase the specificity of clinical usage and contraindications. These conclusions are tentative and must be verified by clinical observation.

While the average clinician may give lip service to understanding herbs in terms of their physiological actions, in the typical clinical setting this knowledge is of only theoretical interest, because the physiological parameters are unknown due to constraints of expense and time. What is easily known or verified are the client's symptoms, his or her tongue and pulse qualities, behavior, and body characteristics. Clients and patients would ultimately benefit if researchers and authors would begin compiling herbal information in a form that is more easily accessible to clinical herbalists.

Research on the clinical effects of herbs should begin to differentiate medical conditions more specifically into the clinical subtypes that in TCM are found to be essential in applying an herb correctly and without side-effects.

References

Reference —{{ links }} will appear in a new window.

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  • [1b] "The Ames Test"; In: webpage at —{{  http://www.life.uiuc.edu/micro/316/topics/rev-sup/ames.html  }}
  • [1c] Ames, B., Lee, F., and Durston, W. "An improved bacterial test system for the detection and classification of mutagens and carcinogens." Proc. Natl. Acad. Sci. USA 70:782-786 (1973).
  • [2a] Trichopoulos, D., Li, F.P., and Hunter, D.J.; "What causes cancer?"; Scientific American, 1996 Sept.; In: webpage at —{{  http://www.sciam.com/0996issue/0996trichopoulos.html  }}
  • [2b] Tsugane S, et al.; "Urinary salt excretion and stomach cancer mortality among four Japanese populations." Cancer Causes Control, 1991 May; 2(3):165-8. Abstract in: webpage at —{{  http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=1873446&form=6&db=m&Dopt=r  }}
  • [3] Wicke, R.W.; "A world history of herbology and herbalism: oppressed arts." ©1995; In webpage at: —{{  http://www.rmhiherbal.org/a/f.ahr1.hist.html  }}
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  • [6] ibid., p.192-197.
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  • [11-a] Weber, W.A.; Rocky Mountain Flora; Colorado Associated University Press, Boulder, Colorado, ©1976.
  • [11-b] Hitchcock, C.L. and Cronquist, A.; Flora of the Pacific Northwest; Univ. of Washington Press, Seattle, ©1973.
  • [12] Hoffman, David L.; "Herbal Materia Medica"; In: webpage at —{{  http://www.healthy.net/clinic/therapy/herbal/herbic/herbs/index.html  }} (as posted 2000 June).
  • [13] Moore, Michael; "Oregon Grape Root"; Medicinal Plants of the Mountain West; Museum of New Mexico Press, Santa Fe, New Mexico, ©1979.
  • [14] Christopher, John R.; School of Natural Healing; BiWorld Publishers, Provo, Utah, ©1976.
  • [15] HerbMed Database; Alternative Medicine Foundation; In: webpage at —{{  http://www.amfoundation.org/herbs/berbmahon.htm  }} (as posted 2000 June).
  • [16] Duke, James; Dr. Duke's Phytochemical and Ethnobotanical Databases; Agricultural Research Service; Entry for "Mahonia" in: webpage at —{{  http://www.ars-grin.gov/cgi-bin/duke/farmacy2.pl  }} (written 1994 Sept., last updated 1998 March 10).
  • [17] Moerman, D.E. and Beckstrom-Sternberg, S.M.; Medicinal Plants of Native America; In: webpage at —{{  http://ars-genome.cornell.edu:80/cgi-bin/WebAce/webace?seme=2&db=mpnadb&class=Taxon&object=Berberis%20repens  }} (as posted 2000 June).
  • [18] Chinese Herbal Medicine: Materia Medica; Dan Bensky and Andrew Gamble, ed.; Eastland Press, Seattle, ©1986, p.107-116.
  • [19] Wicke, R.W.; Traditional Chinese Herbal Science: volume 1, The Language and Patterns of Life (5th ed.); Rocky Mountain Herbal Institute, Hot Springs, Montana, ©1994.