
Copyright 2003
by
Francis Brinker, N.D.
[excerpts]
No reproductions allowed without written consent from the author.
Preface
What is an herb? In botany the understanding of herb is a plant with a fleshy rather than a woody stem, which, after the plant has bloomed and set seed, dies down to the ground. However, the word “herb” has other meanings that expand the concept. The word is derived from the Old Sanskrit bharb, meaning “to eat;” this eventually became the Latin berba, used for “fodder.” The early English used the word herb as synonymous with vegetables. Later, this was restricted to parts of vegetables that grow above ground. In medicine an herb refers to a plant whose properties allow its use therapeutically. Some are also used as seasonings. In the culinary arts, compared to spices herbs are mild fresh or dried leaves, while spices involve more pungent seeds, roots, fruits, flowers, and bark. Generally, an herb is a plant or plant part valued for its medicinal, savory, or aromatic properties. In all of these cases, an herb is a fresh or dried plant or its useful part. Herbs descriptions all involve the intact substance of the plant, including its fiber but sometimes excluding the water. A plant extract is not an herb.
What is a drug? The term drug has different meanings in different times and contexts. Legal definitions and common understandings vary. Most people consider drugs as medicines or substances of abuse, as nonfood items that affect function and sometimes behavior. Herbs and their products are caught in the middle of this web of nomenclature. In the following discussions of herbal medicines, confusion may arise as to the proper designation of these products. A brief explanation is necessary to help guide the reader through this maze. The word ‘drug’ was derived from the Dutch work droog, meaning “dried,” and from the Anglo-Saxon drigan, indicating “to dry.” As recently as 100 years ago in the pharmaceutical profession, drugs were understood as the dried herbs from which medicinal extracts were produced. This is apparent in the many quotations taken from writings by the president of the American Pharmaceutical Association at that time, the Eclectic pharmacist John Uri Lloyd.
During this same period naturopaths were calling themselves drugless practitioners and using common dried herbs and their water extracts, considering them as foods. By naturopathic reckoning, toxic herbs, alcoholic tinctures, concentrated extracts and isolated compounds from botanical remedies were drugs. This belief was supported by the fact that during this time botanical agents comprised half of medications listed in the United States Pharmacopoeia (USP), the official American drug compendium. In addition, the USP contained many isolated compounds derived from plants. In the naturopathic context most nonaqueous derivatives of herbs used as official drugs were undesirable. Synthetic medications, referred to as “coal tar derivatives,” were anathema.
With the passage of time, many alcoholic extracts became accepted by naturopathic doctors as also providing in large part the desirable complex nature of the whole herb. Such preparations as juice, teas, and tinctures can be considered native extracts. Native extracts are liquid fractions prepared by simple extraction procedures from the fresh or dried herb and consumed without further alteration of this form. Another term often used to describe these native extracts is “crude extracts.” Nontoxic herbs and their native extracts are no longer considered as drugs, and their use remains commonplace among the general public. Ultimately, they became so popular that a law was passed to assure continuing access to these and other nutrients. In 1994 the Dietary Supplement Health and Education Act (DSHEA) included herb products under the official designation as dietary supplements in the United States. Herbs and their derivatives are now being included in the National Formulary, a publication of the USP Convention, even though they are not considered as drugs.
The past 50 years has seen an increased medicalization of American culture, along with an increased reliance upon synthesized pharmaceutical medications. Those botanical derivatives that are now officially designated as drugs in the USP are almost exclusively concentrated subfractions or isolated components, many of which have been altered at the molecular level for patent purposes. Even the use of concentrated extracts remains rare in American medicine, compared to European nations and Germany in particular. The emphasis on pharmaceutical extracts of botanicals in Europe has led to increasing clinical studies of these concentrates and has allowed for their official approval there as drugs. These phytopharmaceutical drugs are often concentrated subfractions of native extracts, produced by multiple purification steps using toxic chemical solvents. Yet, when these products are imported to the United States, they qualify under the DSHEA regulations as dietary supplements and are referred to as herbs. Such concentrated fractions for all intents and purposes are increasingly like conventional pharmaceutical drugs, the isolated compounds typically preferred in American medical practice.
The reduction of an intact complex herb to a native extract using water and/or ethanol represents the first level of fractionation of botanicals. A diminished complexity results, but these traditional selective liquid extracts are quite appropriate for specific conditions. The reduction of a native extract to a concentrated fraction allows a lower dose in exchange for even more limited activity. The final stage of reduction to a purified chemical compound provides a greater selective strength. Typically, an isolate is more rapidly absorbed and reaches greater tissue concentrations, but the greater bioavailability and potency is often associated with elevated risks as well.
Each person is confronted with important life choices each day. When it comes to health care and medicinal agents, such choices abound. Each individual must decide whether their preference should be for the greatest nutrient and phytochemical complexity as found in the whole herb and in a somewhat reduced content with native extracts. Or, are the concentrated fractions or their isolated drug constituents more desirable? It becomes more confusing when the extract is called a herb and the fraction is referred to as an extract. It is exasperating when the fraction is marketed as an herb. Dried herb, extract, fraction or isolate, each at some time likely to be called a drug, all have a living plant as their source. How close to the source do you want to be? This book provides information to help understand the differences, so that decisions can be made with a better grasp of the issues involved.
The second part of this book looks at examples of herbs whose products are popular in America. The uses of the different types of product forms are discussed from a historical perspective. This is intended to show both how our understanding of the herb, its extracts, and its fractions and isolated components has developed and how the uses of the various forms are in some ways similar and in other ways different. Emphasis on the acknowledged activities and uses for each of the forms provides a means for recognizing the unique features of each. While each form has some features that are similar, each also needs to be understood in terms of its own peculiar nature to appreciate its optimal applications in health care. Since the whole is greater than the sum of its parts, the potential found in the living plant remains the basis for each different form.
Introduction
MEDICINE AS FOOD
[The following is taken from end of this first section of the Introduction.]
Ultimately, the standard of
high quality is the fresh plant part that contains the desirable features. This
is the form that rightfully deserves to be described by the plant name.
Whatever is made from the fresh part should be described in relation to this
form. Dr. Ed Alstat likes to use a common food to illustrate this issue. Grapes (Vitis vinifera) are known to be powerful contributors to health as
demonstrated by Johanna Brandt and her “grape cure,’ in which the whole fresh
grape was consumed with its skin, pulp, and seeds. Visit any grocery store and
find in the fruit aisle fresh red and green grapes with and without seeds.
Another aisle has raisins, dark and golden. Moving through the store you can
find white and Concord grape juices. In the condiment aisle will be red wine
vinegar. In the freezers are found frozen concentrated grape juices. Many
states allow a liquor section where many varieties and vintages of wine will be
available, along with distilled brandy. Now, if grapes were like most herbs,
these products would all be called “grapes.” Does it matter if it’s raisins or
red wine that you put on your bran for breakfast?
What are some of the
differences in these various forms of grapes? In 2000 Karadeniz and others
found that compared to fresh Thompson Seedless grapes (Vitis vinifera
cv. sultanina), loss of the major phenolic acids were on the order of 90%
in sun-dried raisins and air-dried dark or golden (treated with sulfur dioxide
- SO2) raisins made from these grapes, with golden raisins retaining
the most. Procyanidins and catechins in the raisin samples were completely
degraded, while the flavonol content was not greatly influenced. Spanos and
Wrolstad in 1990 looked at juice processing of Thompson Seedless grapes. They
found that SO2 addition gave higher levels of phenolic acids and
procyanidins but not quercetin glycosides, while enzymatic clarification
hydrolyzed the latter two. Heating during bottling and concentration reduced
procyanidins, while storing concentrates for 9 months at room temperature
markedly lowered phenolic acids and completely destroyed procyanidins and
quercetin glycosides. Seedless grapes lack certain anti-oxidants to begin with.
Of the 30 types of oligomeric procyanidins in grape seeds, Souquet and others
found in 1996 that these are limited to the 7 in the skins of Merlot grapes (V.
vinifera var. Merlot). Furthermore, the grape skin and seeds with their
procyanidins and the skin’s anthocyanins, phenolic acids, and flavonols are
removed in the production of white wine. These phenolics make up important taste and health components that
vary among Bordeaux red wines such as Merlot, as described in 1984 by
Salagoity-Auguste and Bertrand. Sources, parts, and processing matter greatly.
Karadeniz F, et al.
Polyphenolic compostition of raisins. J. Agric. Food Chem., 48:5343-50,
2000
Salagoity-Auguste M-H & Bertrand
A. Wine phenolics – Analysis of low molecular weight components by high
performance liquid chromatography. J.
Sci. Foood Agric., 35:1241-7, 1984
Souquet J-M, et al.
Polymeric proanthocyanidins from grape skins. Phytochem., 43(2):509-12,
1996
Spanos GA & Wrolstad RE.
Influence of processing and storage on the phenolic composition of Thompson
Seedless grape juice. J. Agric. Food Chem., 38:1565-71, 1990
The
Challenge Of Complexity –
Distinctions
Between Herb Products
The order in this list follows a steady reduction in content of plant compounds that may serve as adjuvants, agonists, antagonists, buffers, emulsifiers, enzymes, fiber, metabolism inducers and inhibitors, preservatives, stabilizers, synergists, etc. In general, some carriers (solvents, fillers, binders), preservatives, stabilizers, flavors, and/or other additives are present in most forms listed below. These additives usually range in relative content from the lesser amount with herbs (such as capsules) to greater amounts in native extracts (such as ethanol), simplified fractions and isolates.
MOST COMPLEX
HERB
Common
name(s)
Scientific binomial (Genus & species)
Plant part
Fresh
Frozen
Dried (freeze-dried >
shade > sun > oven)
bulk
cut/sifted
powdered/capsule
NATIVE
EXTRACTS Fresh
extracts:
(Complex
Fractions) fresh
juice
bottled juice
freeze-dried juice
preserved juice
green tincture
homeopathic mother tincture
(1:10)
Liquid extract of dried
plant part:
decoction
infusion
cold
influsion
tincture
(hydro-alcoholic) (1:4 - 1:5)
spagyric extract
(hydro-alcoholic + ash of marc)
fluid extract (1:1)
Solid extract
Standardized
concentrate (2:1 – 10:1)
SIMPLIFIED
FRACTIONS Standardized
(multiple-solvent) fraction (10:1 –
50:1)
(Extract
Subfractions) Fixed
(nonvolatile) oils (50:1 – 100:1)
Aromatic (volatile) oils
(50:1 – 100:1)
ISOLATED
CONSTITUENTS Crystalline
drug salts
(Purified
Compounds)
LEAST
COMPLEX
Glossary
of Terms from Table 1 as Used in This Text
HERB – intact plant or utilized
structures retaining fiber and complete phytochemical content
Common name(s) – describes herb or, sometimes, several similar herbs
Scientific name – identifies plant species
distinct from generically similar plants
Plant part – medicinally active
portion(s); often distinct parts have different activities
Fresh – recently separated from entire
living plant; cells and tissues still alive and growing
Frozen –plant content preserved by
suspending animation with extremely low temperature
Dried (1.freeze-dried > 2.shade > 3.oven >
4.sun) – removal of water to minimize changes
by: 1. freezing plant and slowly heating to remove
water vapor in vacuum;
2. slowly drying away from intense light;
3.
rapidly drying in high heat
4.
rapidly drying in intense light
bulk – dry herb parts in whole uncut
form
cut/sifted –dry herb parts chopped into slices or
small pieces to increase surface area
powdered – dried herb parts ground into fine powder
to greatly increase surface area
NATIVE EXTRACTS (Complex Fractions) – primary soluble portion of phytochemicals removed from the herb by a liquid solvent and/or heat and/or pressure, used to draw multiple types of compounds out of herb tissue matrix and into solution
Fresh extracts: liquid portions taken
from living plant tissues
fresh juice – recently expressed watery liquid from
one or more plant parts
freeze-dried juice – fresh juice frozen, then water
slowly removed under a vacuum
frozen concentrate – juice with most water removed, then
frozen
stabilized juice – bottled juice sealed under a
vacuum, usually pasteurized (heated)
preserved juice – juice with additives (like
alcohol) to prevent fermentation/degradation
green (specific) tincture – fresh plant part extracted at fresh herb weight to solvent
volume ratio of 1:1
using a water/alcohol mixture
homeopathic mother tincture
– fresh plant extract at 1:10 ratio with water/alcohol mixture
Liquid extracts of dried plant part:
complex mixture of plant compounds removed with a solvent
decoction – solution from simmering cut
herb in water at low heat for > 15 minutes
infusion – solution from soaking cut
herb in hot (boiled) water for 5-15 minutes
cold infusion – solution from soaking cut
herb in water at room-temperature for hours
tincture – extract of dried plant part, dry herb weight to solvent volume ratio usually 1:4 or 1:5, soaked in water/alcohol solvent for up to 14 days
spagyric extract – water/alcohol plant extract
with ash from burnt plant marc added back
fluid extract – water/alcohol extract of powdered plant part, weight to volume ratio 1:1, first soaked and then slowly percolated over several days
Solid extract – powder obtained from liquid
extract by removing solvent with heat and drying
standardized concentrate – contains most dissolved compounds found in a primary solvent extract and a consistent marker compound content, having ratio of original dry herb weight to final extract weight 2:1 – 10:1, along with excipients
SIMPLIFIED FRACTIONS
(Extract Subfractions) – secondary extracts of complex
fractions to concentrate select compounds; specific chemical portions separated
from extracts
Standardized derivatives – multiple solvent extractions concentrate active component(s) to specific content; ratio of dry herb to final extract weight 10:1 – 50:1
Fixed or aromatic oils – lipid fraction removed by solvents (both) or cold pressure (fixed), or distilled with heat (aromatics); concentration ratio of dry herb to oil 50:1 – 100:1
ISOLATED CONSTITUENTS (Isolates; Purified Compounds) – phytochemicals that have been separated from their complex natural matrices; single molecular components removed from complex mixtures, often by fractionation followed by precipitation
Crystalline drug salts – single constituents altered through chemical processes that result in formation of drugs with ionic bonds that will dissolve in liquids
Table 2. Product Content
Trends
When Moving From Whole Herb
to Fractions to Isolates
MOST COMPLEX LEAST COMPLEX
|
|
Herb (Complete
Complexities) |
Native Extracts (Complex Fractions) |
Simplified Fractions (Extract Subfractions) |
Isolated Constituents (Purified Compounds) |
|
Number of Additives |
X |
XX |
XXXX |
XXXXXX |
|
Bioactive Constituents |
XXXXXX |
XXXX |
XX |
X |
|
Constituents Lost |
X |
XX |
XXXX |
XXXXXX |
COMPARATIVE DOSES
Concentrates
A mistaken assumption is constantly being promoted
that a therapeutic equivalency exists between a certain weight of a whole herb and
extracts made from that same weight. Based on the fact that any extract
provides only a fraction of the total herb, and only some of any total
component content, this clearly is not the case. Even if the whole herb
contained only one biologically active component (a situation that is virtually
unknown), no commercially employed extraction process will completely exhaust
the herb of its content of the active compound. The most common means of making
herbal liquid extracts (referred to as tinctures) is with a process known as
maceration. When herbs are soaked
(macerated) in a solvent made of a mixture of water and alcohol (ethanol), the
extraction process stops when the concentration of a compound in the solvent
equals the concentration remaining in the extracted herb (equilibrium), known
as the marc. Relatively complete
extraction of certain components in the herb can only occur under these
conditions if the amount of solvent is great and little herb is used, resulting
in an extract that is extremely weak. Even this will only occur if the
compounds in the herb are completely soluble in the ratio of water to alcohol
used. When using a water/alcohol mixture as the extracting solvent, a complete
solubility, and therefore extraction, does not occur for any single compound,
much less all of the components simultaneously.
The process that most closely approaches complete
extraction of certain components of the herb is called percolation. Percolation
is typically applied to the manufacture of concentrated fluid extracts. By
allowing a slow, steady flow of solvent to pass through the ground herb loosely
packed in a column, the fresh solvent added to the top of the column is much
more effective in extracting the components than when it reaches the bottom of
the column where it is concentrated with extracted components. Even using this
method, to completely remove the remaining active components from the herb in
the bottom of the column, the final portion of extract is so dilute that it must
be concentrated after the extraction is complete. This process employs the
application of heat to drive off the excess solvent and reduce the volume.
Heating the extract is destructive to many compounds, thereby changing the
content and rendering the extract less complex and less potent. As a
consequence the extract does not provide all of the original component content
and activity present in the whole herb amount that was extracted. Study of the
essential oil content in thyme and its extracts has shown in general that the
greater the degree of concentrating the extract, the lower the percentage of
original content of the whole herb is contained in the final extract.
While this deficit in the retention of content by
concentrating extracts is recognized and acknowledged, an associated error in
logic is being propagated in the meantime. This faulty reasoning takes as a
standard the effective dose of a concentrated herbal extract and then attempts
to determine the equivalent dosage of the whole herb calculated on the basis of
the degree of concentration by weight that has occurred. In other words, a 5:1 extract whose dosage
quantity (for example, 100 mg) represents components extracted from a greater
weight of whole herb (in this case, 500 mg) is regarded as five times more
potent (a fallacy). As a consequence, it is believed that to get equivalent
activity using the whole herb, five time as much of the herb must be used (a
further fallacy). It is on this faulty premise that the proposed dosage
equivalency of whole herbs compared to extracts is misrepresented to the public
and practitioners alike.
STANDARDIZED EXTRACTS
Confusion in the
ranks – Standardization claims for products of popular herbs
Echinacea
[Example discussing
one genus taken from this section.]
A final example of standardization
illustrates how its use can be misconstrued in evaluating the quality, and even
the identity, of products. In an attempt to assess the validity of label
claims, in 2003 Gilroy and others obtained 59 preparations sold as echinacea in
the Denver metropolitan area. The investigators decided to use thin layer
chromatography (TLC) as a means of determining the legitimacy of content claims
for these products. They based the interpretation of their findings on the
assumption that the relative content of Echinacea purpurea could be
determined by the cichoric acid yield. They also assayed echinacoside as the
marker for E. angustifolia to
differentiate these two species.
The third commercial echinacea species, E.
pallida, also contains echinacoside, therefore this marker could not be
used as a means of distinguishing this species from E. angustifolia.
Five of the 59 samples were identified on their labels as E. pallida, but the authors state that differentiating between
it and E. angustifolia “was never a concern.” Unfortunately, the authors
failed to note claims about the part of the plant used. Normally, E. pallida
and E. angustifolia roots are the parts used for such products. If this
is true for these samples, species identification can be made by the caffeoyl
phenolic compound cynarin present in E. angustifolia roots but absent in
E. pallida roots (and E. purpurea as well), as shown by Perry and
others in 2001.
The roots can also be easily distinguished due to E.
pallida root’s lack of the tongue-tingling isobutylamides that typify E. angustifolia
(and E. purpurea). Isobutylamides and the polyacetylene or 2-ketoalkenes and 2-ketoalkyne components found in E.
pallida are readily demonstrable by TLC. The authors referenced the
research by Bauer and Remiger in 1989 that describe these differences with TLC,
but surprisingly use this means to only identify the phenolic markers. In
addition, Cheminat and others determined in 1988 that cichoric acid was the
main phenolic product in E. pallida flowers and leaves, with some was
present in the root as well. Likewise, Perry and others in 2001 found cichoric
acid in E. angustifolia roots, making this a nonspecific marker for
absolutely identifying E. purpurea.
The inadequacy of using the phenolics, cichoric acid and echinacoside,
as suitable echinacea markers, as well as not characterizing the processed
forms of the samples, come to bear on the issue of evaluating E. purpurea
products. The juice of the aerial plant preserved with 22% ethanol is an
established remedy, and the most researched echinacea product on the market. In
1999 both Bauer and Kreuter indicated that the enzyme polyphenol oxidase
rapidly breaks down cichoric acid in the cold-pressed fresh juice. Kreuter
pointed out that clinical research had employed the cold-pressed and unheated
E. purpurea plant juice, so only this juice with little or no cichoric acid
has been proven clinically effective. When the juice is heated to destroy the
enzyme, cichoric acid will be consistently retained. However, in 1999 Bauer
found that heat-stabilized juice products had much lower isobutylamide content
on average. The isobutylamide components are believed to be more
therapeutically active as immune enhancers than the cichoric acid.
Arnason reported that in 1998 Bauer observed that
cichoric acid declines in tinctures in six days. Livesey and others indicated
in 1999 that cichoric acid diminished in tinctures with 55% alcohol at room
temperature after 7 months but was stable in powder during this time even at
higher temperatures. Nusslein and others in 2000 showed cichoric acid could be
preserved in aqueous extracts over four weeks by adding 50 mM ascorbic acid or
40% ethanol. Thus, it is obviously necessary to characterize the form of the
product when assessing relative cichoric acid content, rather than generalizing
average content to all forms.
In their evaluation Gilroy and others did not
identify these products as powdered root/plant or extracts, but simply reported
that 9 were tablets, 32 were capsules, 4 were softgels, and 14 were liquids.
Only 21 of the products were standardized, but their forms were not specified.
The standardized products had much lower recommended doses, suggesting that
these were solid extracts rather than the root. It is obvious that the softgels
and liquids were extracts, as were likely some of the tablets and capsules.
Whether these were processed as pressed plant juice, its dried powder, or as
liquid or solid solvent extracts of fresh or dried roots cannot be deduced. Nonetheless,
not all extracts are standardized, so we don’t know from the information given
what the forms of the standardized products were. Calling all of the products
simply echinacea is inherently misleading, since they represent many possible
identities: root, aerial plant, juice, or their solvent extracts and
concentrates.
The authors’ premise in assessing the content of the
particular caffeoyl phenolic markers is understandable, since these compounds
are typically used to “standardize” products of these species. They addressed
those products that claimed to be standardized to specific phenolics. Of the
nine samples that identified either echinacoside or cichoric acid as markers,
none matched the label claim. Rather, seven had on average only 26% of the label
claims, and the other two contained no measurable amounts. Ten product labels
made claims to be standardized to total phenolics, but this fails to
distinguish between particular species markers. In his talk at an international
echinacea conference in 1999 Arnason noted that even though the total phenolic
content had been the common echinacea standard for years, it was a “completely,
utterly useless measure, in the opinion of all the phytochemists in the room,
as to the quality of echinacea products.”
Gilroy and others assayed phenolic marker content of
standardized products as well as those whose identifying label claim was simply
the species used in the product. It is
interesting to note that, based on their phenolic evaluation approach, 21 of 30
(70%) of the nonstandardized products matched the label species claim, while
only 10 of 19 (53%) of the standardized products were presumably the
appropriate species. For those products containing cichoric acid, the
nonstandardized yielded on average about 2.5 times more than the standardized
samples. In the products with echinacoside, the content of nonstandardized
samples averaged more than 3 times the yield of those that were standardized.
The doses of nonstandardized products were about twice those of standardized.
Finally, Gilroy and others claim that only four of
the products (7%) met the four FDA labeling requirements. They observe that the
better compliance score for standardized than nonstandardized products was due
to the presence of the “Supplements Facts” box. However, products that do not
make standardization or structure/function activity claims and companies that
have less than 100 employees are exempt from this label requirement. The
authors’ conclusion that the “claim of “standardization” does not mean the
preparation is accurately labeled, nor does it indicate less variability in
concentration of constituents of the herb,” is an appropriate assessement of
these echinacea products. One could accurately state that standardization
claims provide no basis for determination of quality of these products in terms
of therapeutic efficacy. Trying to evaluate echinacea products on the basis of
phenolic markers without specifying the plant part and form of each preparation
being assessed is meaningless. Even knowing those features is of little value
beyond limited characterization of the product. Quality is a function of
effect, not just identity.
Arnason JT. North American
raw materials: the case for an isobutylamide standardized product. Echin.
Past, Present Future Internat. Conf. 1999 Proc., Session Three, pp. 4-5
& slide 40, Skamania, Wash., June 10-12, 1999
Bauer R. Standardization of
Echinacea purpurea expressed juice with reference to cichoric acid and
alkamides. J. Herbs, Spices Med Plants, 6(3):51-62, 1999
Bauer R & Remiger P. TLC
and HPLC analysis of alkamides in echinacea drugs. Planta Med.,
55:367-71, 1989
Cheminat
A et al. Caffeoyl conjugates from Echinacea species: structures and biological
activity. Phytochem., 27(9):2787-94, 1988
Gilroy
CM et al. Echinacea and truth in labeling. Arch. Int. Med., 163:699-704,
2003
Kreuter M. Echinacea purpurea
substances, characteristics and immunological active principles. Echin.
Past, Present Future Internat. Conf. 1999 Proc., Session Two, p. 3 & slide
7, Skamania, Wash., June 10-12, 1999
Livesey J et al. Effect of
temperature on stability of marker constituents in Echinacea purpurea root
formulations. Phytomed., 6(5):347-9, 1999
Nusslein B et al. Enzymatic
degradation of cichoric acid in Echinacea purpurea preparations. J. Nat.
Prod., 63:1615-1618, 2000
Perry
NB et al. Echinacea standardization: Analytical methods for phenolic compounds
and typical levels in medicinal species. J. Agric. Food Chem.,
49:1702-6, 2001
Table
3. Echinacea Products of Different Types*
(X =
Commercially Available Product)
|
WHOLE
HERB |
|
|
|
|
|
|
Common
name |
Echinacea |
Echinacea |
Echinacea |
Echinacea |
Echinacea |
|
Scientific
names |
Echinacea
angustifolia |
Echinacea
pallida |
Echinacea
purpurea |
Echinacea purpurea |
Echinacea
purpurea |
|
Plant
part |
Root |
Root |
Whole plant |
Aerial plant |
Root |
|
Fresh,
living |
|
|
X |
|
|
|
Freeze-dried |
X |
|
|
X |
X |
|
Air/oven
dried: bulk |
X |
X |
|
|