COMMUNITY HERBAL MONOGRAPH ON
ECHINACEA PURPUREA
(L.) MOENCH, HERBA RECENS
To be specified for the individual finished product.
Well-established use
Traditional use
With regard to the marketing authorisation
application of Article 10(a) of directive
2001/83/EC, as amended
With regard to the registration application of
Article 16d(1) of directive 2001/83/EC, as
amended
Echinacea purpurea
(L.) Moench, herba recens
(purple coneflower herb)
Echinacea purpurea
(L.) Moench, herba recens
(purple coneflower herb)
i) Herbal substance
Not applicable
i) Herbal substance
Not applicable
ii) Herbal preparations
-
expressed juice.
-
dried expressed juice.
ii) Herbal preparations
-
expressed juice
-
dried expressed juice.
Well-established use
Traditional use
Herbal preparations in solid or liquid dosage forms
for oral use.
Herbal preparations in semi-solid or liquid dosage
form for cutaneous use.
The pharmaceutical form should be described by
the European Pharmacopoeia full standard term.
The pharmaceutical form should be described by
the European Pharmacopoeia full standard term.
4.1.
Therapeutic indications
Well-established use
Traditional use
Herbal medicinal product for the short-term
prevention and treatment of common cold.
Traditional herbal medicinal product for treatment
of small superficial wounds.
1
The declaration of the active substance(s) for an individual finished product should be in accordance with
relevant herbal quality guidance.
©
EMEA 2008
2/6
4.2.
Posology and method of administration
Well-established use
Traditional use
Posology
Posology
Adolescents over the age of 12 years, adults,
elderly
Expressed juice 6 – 9 ml per day or equivalent
amount of dried expressed juice, divided in 2 to 4
doses.
Adolescents over the age of 12 years, adults,
elderly
10 to 20 g /100 g of expressed juice or equivalent
amount of dried expressed juice
Small amount of ointment is applied on the
affected area 2-3 times a day.
Paediatric population
The use in children below 1 year of age is
contraindicated (see 4.3. Contraindications)
The use in children between 1 and 12 years of age
is not recommended (see 4.4. Special warnings
and precautions for use).
The use in children below 12 years of age is not
recommended (see 4.4. Special warnings and
precautions for use).
Duration of use
Duration of use
For prevention and treatment, do not use the
medicinal product for more than 10 days.
Do not use the medicinal product for more than
1 week.
For treatment, start the therapy at first signs of
common cold.
If the symptoms persist for more than 10 days, a
doctor or a pharmacist should be consulted.
If the symptoms persist during the use of the
medicinal product, a doctor or a qualified health
care practitioner should be consulted.
Method of administration
Method of administration
Oral use
Cutaneous use
4.3.
Contraindications
Well-established use
Traditional use
Hypersensitivity to the active substance or to
plants of the Asteraceae (Compositae) family.
Hypersensitivity to the active substance or to
plants of the Asteraceae (Compositae) family.
Because of its immunostimulating activity,
Echinacea must not be used in cases of progressive
systemic disorders, autoimmune diseases,
immunodeficiencies, immunosuppression and
diseases of the white blood cell system.
Children under 1 year of age.
©
EMEA 2008
3/6
4.4.
Special warnings and precautions for use
Well-established use
Traditional use
If the symptoms worsen or high fever occurs
during the use of the product, a physician or a
pharmacist should be consulted.
If signs of skin infection are observed, medical
advice should be sought.
The use in children below 12 years of age is not
recommended because a safe use has not been
sufficiently documented.
There is a possible risk of anaphylactic reactions
in atopic patients. Atopic patients should consult
their doctor before using Echinacea.
The use in children is not recommended because
efficacy has not been sufficiently documented
although specific risk in children over 1 year of
age is not documented.
4.5.
Interactions with other medicinal products and other forms of interaction
Well-established use
Traditional use
None reported.
None reported.
4.6.
Pregnancy and lactation
Well-established use
Traditional use
Limited data (several hundreds of exposed
pregnancies) indicate no adverse effects of
Echinacea on pregnancy or on the health of the
foetus/newborn child. Data concerning the
immune system of the newborn child are not
available. To date, no other relevant
epidemiological data are available.
There are no data on use during pregnancy or
lactation.
No concern has arisen about any malformation in
humans.
Products containing Echinacea should not be
applied to the breast of breastfeeding women.
In the absence of sufficient data, the use in
pregnancy and lactation is not recommended
unless advised by a doctor.
4.7.
Effects on ability to drive and use machines
Well-established use
Traditional use
No studies on the effects on the ability to drive and
use machines have been performed.
No studies on the effects on the ability to drive and
use machines have been performed.
©
EMEA 2008
4/6
4.8.
Undesirable effects
Well-established use
Traditional use
Hypersensitive reactions (rash, urticaria, Stevens-
Johnson Syndrome, angioedema of the skin,
Quincke edema, bronchospasm with obstruction,
asthma and anaphylactic shock) may occur.
Echinacea can trigger allergic reactions in atopic
patients.
Association with autoimmune diseases
(encephalitis disseminata, erythema nodosum,
immunothrombocytopenia, Evans Syndrome,
Sjögren syndrome with renal tubular dysfunction)
has been reported.
Leucopenia may occur in long-term use (more
than 8 weeks).
The frequency is not known. If other adverse
reactions not mentioned above occur, a doctor or a
pharmacist should be consulted.
Hypersensitive reactions (local rash, contact
dermatitis, eczema and angioedema of the lips)
may occur.
The frequency is not known.
If other adverse reactions not mentioned above
occur, a doctor or a qualified health care
practitioner should be consulted.
Well-established use
Traditional use
No case of overdose has been reported.
No case of overdose has been reported.
5.1.
Pharmacodynamic properties
Well-established use
Traditional use
Pharmacotherapeutic group: ATC-code:
L03AW05 immunomodulators of plant origin
R07AX other preparations for respiratory system
Not required as per Article 16c(1)(a)(iii) of
Directive 2001/83/EC as amended.
Echinacea purpurea
stimulates nonspecific
immune system (phagocytosis by macrophages,
natural killer cells activity).
5.2.
Pharmacokinetic properties
Well-established use
Traditional use
No data available.
Not required as per Article 16c(1)(a)(iii) of
Directive 2001/83/EC as amended.
©
EMEA 2008
5/6
5.3.
Preclinical safety data
Well-established use
Traditional use
Echinacea purpurea
showed no toxicity in single-
dose toxicity (rodents), repeated-dose toxicity
(rodents) and genotoxicity studies.
Not required as per Article 16c(1)(a)(iii) of
Directive 2001/83/EC as amended, unless
necessary for the safe use of the product.
Tests on reproductive toxicity and on
carcinogenicity have not been performed.
Echinacea purpurea
showed no toxicity in single-
dose toxicity, repeated-dose toxicity and genotoxi-
city studies.
Tests on local tolerance, reproductive toxicity and
on carcinogenicity have not been performed.
Well-established use
Traditional use
Not applicable.
Not applicable.
8 May 2008
©
EMEA 2008
6/6
Assessment Report
TABLE OF CONTENTS
1
Introduction
.......................................................................................................................... 3
2
Pharmacology
....................................................................................................................... 8
2.1
Pharmacokinetics
.......................................................................................................... 8
2.1.1
Phytochemical characterisation
.................................................................................. 8
2.1.2
Absorption, metabolism and excretion
........................................................................ 9
2.2
Pharmacodynamics
..................................................................................................... 11
2.2.1
Animal studies
........................................................................................................ 11
2.2.2
Human studies
........................................................................................................ 15
2.3
Interactions
................................................................................................................. 16
3
Clinical Efficacy
................................................................................................................. 17
3.1
Clinical studies
........................................................................................................... 17
3.1.1
Placebo-controlled trials on
E. purpurea
expressed juice for treatment of URTI
.......... 22
3.1.2
Non-controlled trial
................................................................................................. 23
3.1.3
Trials on other indications (prevention) and other preparations (extract) or combinations.
24
3.2
Use in special populations
........................................................................................... 27
3.2.1
Use during pregnancy and lactation
.......................................................................... 27
3.3
Dosage
....................................................................................................................... 29
3.4
Traditional use
............................................................................................................ 29
4
Safety
................................................................................................................................. 30
4.1
Toxicity
..................................................................................................................... 30
4.1.1
Single-Dose Toxicity
.............................................................................................. 30
4.1.2
Repeat-Dose Toxicity
.............................................................................................. 30
4.1.3
Genotoxicity
........................................................................................................... 30
4.1.4
Carcinogenicity
...................................................................................................... 31
4.1.5
Reproductive and Developmental Toxicity
............................................................... 31
4.1.6
Local Tolerance
...................................................................................................... 31
4.1.7
Immunotoxicity
...................................................................................................... 31
4.2
Contraindications
........................................................................................................ 32
4.3
Special warnings/precautions for use
............................................................................ 32
4.4
Undesirable effects
..................................................................................................... 33
4.5
Interactions
................................................................................................................. 34
4.6
Overdose
.................................................................................................................... 34
5
Overall Conclusion
............................................................................................................. 34
Community herbal monographs
Annex
Community list entries
Annex
©
EMEA 2008
2/35
References
Annex
1
Introduction
Assessment report reviews the scientific data, particularly the pharmacological and clinical data,
available for the
Echinacea purpurea
(L.) Moench (syn:
Rudbekia purpurea
L.), herba and the herbal
medicinal products thereof.
The monograph in European Pharmacopoeia defines the herbal substance “Purple coneflower herb”
as:
Dried, whole or cut flowering aerial parts of
Echinacea purpurea
(L.) Moench.
Content: minimum 0.1 per cent for the sum of caftaric acid (C
13
H
12
O
9
; M
r
312.2) and cichoric acid
C
22
H
18
O
12
; M
r
474.3) (dried drug).
US Pharmacopeia contains the monograph “
Echinacea purpurea
Aerial Parts”, which defines the drug
as: “consists of the aerial parts of
Echinacea purpurea
(L.) Moench (Fam. Asteraceae). It is harvested
during the flowering stage. It contains not less than 1.0 percent of chichoric acid, and not less than
0.01 percent of dodecatetraenoic acid isobutylamides (C
16
H
25
NO) on the dry basis.” (
Giancaspro
2004)
There is no pharmacopoeial monograph for the fresh plant.
Preparations from plant parts of
Echinacea
species rank among the medicines longest used in the
American people’s medicine.
Echinacea
was well known for a long time by the Indian tribes in
Nebraska and Missouri. The immunostimulating effect was later also used by the European
immigrants. At the beginning of the 20th century,
Echinacea
was the best-selling American medical
plant in the United States (Foster 1996). In the lasts decades
Echinacea
-containing medicinal products
became among the most popular medicinal products in Europe.
There are three species of
Echinacea
mostly used in phytotherapy:
E. purpurea, E. angustifolia
and
E.
palida
, but there are also some reports of the use of
E. simulata
and
E. paradoxa
(Bauer & Foster
1991).
E. purpurea
is sometimes adulterated with other
Echinacea
species (HagerROM 2004) and quite often
mislabelled (Gilroy et al. 2003). Much of the early research reported for
E. angustifolia
and
E.
purpurea
was probably actually conducted on
E. pallida
and studies published prior to 1987 must be
viewed with suspicion in terms of the actual species being evaluated (Bauer et al. 1988c).
Information about the legal status of products containing
Echinacea purpurea,
herba in Member States
(and Associate Members and Observer States):
©
EMEA 2008
3/35
Member state
products, indications
Legal status
Austria
-
Echinacea “Bioforce” drops (Aponova Pharma)
- Echinacea “ratiopharm”tablets (Ratiopharm Arzneimittel)
- Echinacin “Madaus” Capsetten oral gum (Madaus)
- Echinacin “Madaus” pressed juice (Madaus)
- Echinacin “Madaus” tablets (Madaus)
- Echinacin “Madaus” drops (Madaus)
- Sanvita Imun-Solution (Sanamed)
authorised 1991
authorised 2004
authorised 1998
authorised 2000
authorised 2004
authorised 1994
Indications:
Internal use:
Adjuvant therapy and prophylaxis of recurrent infections of
the upper respiratory tract (common colds) and also of the
urogenital tract.
External use:
Semi-solid preparations with a minimum of 15% of pressed
juice.
Dermal wound-healing, after vaccination, insect bites.
Posology
Echinacea purpureae
herba
Internal use:
Adult daily dose: 6-9 ml of pressed juice; other equivalent
preparations at comparable dosage; Children: Proportion of
adult dose according to age or body weight.
Belgium
Medicinal product:
Oral solution
Indication:
Upper respiratory tract infections (serious pathologies
excluded)
Posology:
800mg juice /g;
-adults : 2.5 ml + 1.25 ml after 2 hours, then 3 times 2.5 ml
per day; maximum 15 ml/day
-2 to 12 years : 1 drop per kg bw per day
-below 2 years: prescription only.
April 2000
From January 1990
onwards
E. purpurea
extract registered as homeopatic mother
tincture.
Food supplement
Oral solution, capsules, tablets, syrup, buccal spray
Claims on packaging: improved breathing, favourable
influence on throat
No clear compositions or unambiguous posology available.
Amounts of variable markers are declared, such as
echinacoside, echinacin, echinacein, phytosterols, chicoric
acid, polysaccharides
Czech Republic 4 oral and 1 topical preparation. (DR. RENTSCHLER,
Germany; LEK, Slovenia; 3x MADAUS, Germany)
©
EMEA 2008
4/35
Finland
five products containing
E. purpurea
on a market.
Pharmaceutical forms: oral drops, solution (three products),
tablet (one product) and lozenge (one product).
Indications
:
for one product it is 'To relieve symptoms of cold.' and for
other two products it is 'For symptoms of cold, temporary
cough and irritation of throat. To treat small wounds.'
Indication for lozenges and tablets is 'To relieve symptoms
of cold.'
Posology
:
Varies from product to product. For two oral drop products
the posology is 'For internal use with water 10-20 drops 2-5
times daily. For small wounds 1-2 drops/few drops several
times a day into the wound.' For the third oral drop product
the posology is '40 drops 3 times daily.' For lozenges the
posology is '1 lozenge 3 times daily' and for tablets 'For
adults with water 2 tablets 3-5 times daily about 15 minutes
before meals.'
Two products have
been registered first
time in 1990 and
1991 (two oral drop
products) and the
marketing
authorisations have
been granted for
two products in
1996 (oral drops
and lozenges) and
for one product in
1997 (tablets).
France
No authorized herbal medicinal products containing
Echinacea
are on the market.
No
Germany
85 herbal medicinal products containing
E. purpurea
are on
the market. They exist in various pharmaceutical forms for
oral use: syrup, oral liquid (expressed juice), effervescent
tablet, oral gum, soft capsule, tablet, film-coated tablet,
coated tablet.
Indications
: Adjuvant in (frequently occuring) recurrent
respiratory tract infections and/or urinary tract infections.
Posology:
according to Komission E.
Marketing
authorization
Marketing
authorization for
traditional use
(according to
German Drug Law)
One product for external use.
Indication
:
Herbal medicinal product traditionally used as mild acting
adjuvant in wound healing.
Echinacin® Salbe Madaus: 100 g contains 16 g of expressed
juice
Hungary
4 oral and 1 topical preparation.
Indication:
Prevention and adjuvant therapy of common cold and
influenza; Prophylaxis and adjuvant therapy of recurrent
respiratory and urogenital infection; Adjuvant in wound
healing.
First oral
preparation first
registered in 1992,
topical preparation
first registered in
2000
Ireland
No products containing
Echinacea
currently authorised.
©
EMEA 2008
5/35
Italy
no medicinal products containing only
Echinacea
as active
substance are currently authorised.
No
Food supplements are on the market:
Pharmaceutical forms: liquid form, tablets, capsules, syrup,
spray.
Part of plant used in the preparation: leaves, apical flowers,
stalk,
root, whole plant.
Indications:
may be helpful during the cold season
it may be helpful to enhance natural defenses during the
cold season.
Posology:
it varies according to the different products, and to the part
of the plant used in the preparation.
Apical flowers: the range goes from 25 mg to 144 mg
Whole plant: from 0.14 mg to 7,500 mg
Leaves: from 20 mg to 450 mg
Root: from 3 mg to 2,430 mg
Leaves + root: 4 mg
Leaves + stalk: 200 mg
Methods of administration: oral.
Latvia
1. Echinacea – Ratiopharm 100 mg, Lutschtabletten.
Herba Echinaceae purpureae. Ratiopharm GmbH, Germany.
ATC code: V03AX.
2.Echinacis Madaus Capsetten, Lozenges.
Herba Echinaceae purpureae. Madaus AG, Germany.
ATC code: V03AX.
3.Echinacis Madaus Liquidum, Liquidum.
Herba Echinaceae purpureae. Madaus AG, Germany.
ATC code: V03AX.
4.Futura Echinacea, Chewable tablets.
Extr. Echinaceae purpureae. Dansk Droge A/S, Denmark.
ATC code:V03AX.
5.Immunal tablets, Tablets 80 mg.
Herba, succus Echinaceae purpureae L. siccum. Lek
Pharmaceuticals d.d., Slovenia.
ATC code: V03AX.
6.Immunal, Solution (peroral use).
Herba, succus Echinaceae purpureae L. siccum. Lek
Pharmaceuticals d.d., Slovenia.
ATC code: L03A.
7.Tinctura Echinaceae, Tinctura.
Rhizomata et radices Echinaceae. JSC “Riga Pharmaceutical
Plant”, Latvia.
ATC code: L03A.
Marketing
authorization
Products containing
E. purpurea
are also used as food
supplements.
©
EMEA 2008
6/35
Poland
1) Echinaceae purpureae herbae succus sicc.
2) Echinaceae purpureae herbae extractum
3) Echinaceae purpureae herbae extractum spissum
4) Echinaceae purpureae herbae extractum
1) 2000
2) 1994
3) 1999
4) 1993
5) 2003
6) 1999
7) 2004
5) Echinaceae purpureae herbae extractum
6) Echinaceae purpureae herbae succus
7) Echinaceae purpureae herbae extractum siccum (4.5-
3.5:1); water
Pharmaceutical Form
1) tablets, 100mg
2) ointment, 50mg/g
3) coated tablets, 100mg
4) oral drops, 800mg/ml
5) tablets
6) oral drops
7) tablets, 100mg
Indications:
1) Supplementory in upper airways infections. After medical
consultation also in urinary tract infections.
2) traditionally in troubles with small wound healing
3) Recurrent upper airways infections (common cold),
therapy and prophylaxis.
4) Supplementory in recurrent upper airways infections.
Prophylaxis of common cold.
5) Supplementory in upper airways infections. Prophylaxis
against common cold.
6) Common cold. Recurrent infections of upper airways.
7) Common cold. Supplementory in upper airways cattarhs
and sinusitis.
Portugal
Echinacea purpurea
extract - 16g /100g ointment,
Indications
:
Inflammatory conditions of the skin (eczema), burns. (two
products)
Marketing
authorization at
1996 and 1997,
respectively.
In combination:
Pygeum africanum
extract – 25 mg
Sabal serrulata
dry extract – 200 mg
Echinacea angustifolia
dry extract – 100 mg
Tablets,
Indications
: Prostatic hypertrophy at a early stage and
urinary disturbances.
Marketing
authorization
at
1987
Trospium chloride – 60 mg
Echinacea angustifolia
extract – 60 mg
Sabal serrulata
extract – 60 mg
Capsules, Indications: Urinary Antispasmodic
Marketing
authorization
at
©
EMEA 2008
7/35
1988
Romania
ADDITIVA ECHINACEA effervescent tablet containing
125 mg dried pressed juice (38-56:1) of
E. purpurea
fresh
herb.
Indications
:
immunity stimulation,support treatment for recurrent
respiratory infections.
Posology and administration: Adults: one effervescent tablet
(dissolved in 150 ml water)-3 times daily.
Slovenia
3 herbal medicinal products containing
E. purpurea
are on
the market. One of the products (Echinaforce, Bioforce)
contains also 5% of
E. purpurea
root.
Indications
:
to increase the defence capacity of the body; for prevention
and quicker recovery from cold and influenza; to relieve the
symptoms of disease in mild viral and bacterial respiratory
tract infections (runny nose, sore throat, coughing, fatigue);
in long-term antibiotic treatment of chronic infections
leading to a weakening of patient’s cellular immune
reaction.
Marketing
authorization. One
of the products
(Immunal, Lek) is
on the market for
more than 20 years.
Food supplements are on the market
Sweden
a) ethanol extract (1:3),
b) ethanol/water (62-70%) extract, herb (1:12), root (1:11)
c) dry ethanol/water (57.3%) extract corresponding to fresh
herb 140 mg, fresh root 8 mg
d) fresh herb, dried pressed juice 1 ml corresponding to 2 g
herb
e) fresh herb, pressed juice 160 mg/g ointment
ad a) 2004
ad b) before 1978
ad c) 2004
ad d) 1995
ad e) before 1984
Indications:
ad a) – d) Traditionally used for the relief of cold symptoms.
ad e) Traditionally used for treatment of sores on the lips
and on other small superficial wounds such as chapping in
the corner of the mouth or on the fingertips.
Risks are known.
2
Pharmacology
2.1
Pharmacokinetics
2.1.1
Phytochemical characterisation
The search for active substances of
Echinacea
is not finished. At present mainly three groups of
constituents are regarded as effective principles (ESCOP 2003): caffeic acid derivatives, alkamides,
polysaccharides. Melanins were recently purposed as a new active constituent of
Echinacea purpurea
(Pasco et al. 2005, Pugh et al. 2005).
The caffeic ester derivative cichoric acid (2,3-O-dicaffeoyl-tartaric acid) is the major compound of this
class found in the aerial parts of
Echinacea purpurea
with a concentration range of 1 to 5%, followed
by caftaric acid (2-O-caffeoyl-tartaric acid) (Kreft 2005; Manček & Kreft 2005; Bauer et al. 1988b).
Comercial product can contain as little as 0.13 mg/g of cichoric acid and 0.14 mg/g of caftaric acid
(Gotti et al. 2002). Other derivatives like 2-O-feruloyl-tartaric acid and 2-O-caffeoyl-3-coumaroyl-
©
EMEA 2008
8/35
tartaric acid are present in small quantities. Cynarine and echinacoside are characteristic for other
Echinacea
species and are practically not present in the aerial pars of
Echinacea purpurea
(Gotti et al.
2002).
Further characteristic constituents are a series of alkamides with the isomeric dodeca-2E,4E-
8Z,10E/Z-tetraenoic acid isobutylamide as main compound.
The volatile oil (0.08–0.32%) contains, among other compounds, borneol, bornyl acetate, pentadeca-8-
(Z)-en-2-one, germacrene D, caryophyllene and caryophyllene epoxide. Polysaccharides (PS) such as
PS I, a 4-O-methyl-glucuronoarabinoxylan with an average MW of 35,000 D, and PS II, an acidic
arabinorhamnogalactan of MW 450,000 D, have been isolated from
Echinacea purpurea
herb. A
xyloglucan (MW 79,500 D) has also been isolated from the herb and a pectin-like polysaccharide from
the expressed juice.
Caffeic ac id derivatives
Alka m id es
with tartaric ac id
cichoric acid
caftaric acid
with q uinic a c id
c ynarine
Po ysa c c h a rid e s
with sugar
4-O-methyl-glucurono-arabino-xilan
(m.w. 35 000)
echinacoside
Arabino-rhamno-galactan
(m.w. 450 000)
2.1.2
Absorption, metabolism and excretion
So far no
in vivo
pharmacokinetic investigations were performed on the
Echinacea purpurea
expressed juice. A reason can be found in the fact that the expressed juice is a mixture of many
substances. Pharmacokinetic of caffeic acid and related hydroxycinnamates (Bourne & Rice-Evans
1998; Westendorf & Czok 1978) and of alkamides was studied
in vivo
and
ex vivo
(in cell cultures).
Absorption of alkamides after oral application of
E. purpurea
was studied (Dietz et al. 2001). One
hour after oral application of 65 ml of
Echinacea purpurea
concentrated tincture, containing 4.3 mg of
dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides, it was possible to detect 44 ng of this
alkamide per ml of human blood. An HPLC quantification method has been developed. Since the
©
EMEA 2008
9/35
volume of distribution of the substance in the body is at least 5 litre, it can be calculated that at least
5% of alkamide was absorbed one hour after oral application.
Matthias et al. (2005a) have examined serial plasma samples from 9 healthy volunteers who ingested
tablets manufactured from ethanolic liquid extracts of
Echinacea angustifolia
and
Echinacea purpurea
immediately after a standard high fat breakfast. Caffeic acid conjugates could not be identified in any
plasma sample at any time after tablet ingestion. Alkamides were rapidly absorbed and were
measurable in plasma 20 min after tablet ingestion and remained detectable for up to 12 h.
Concentration-time curves for 2,4-diene and 2-ene alkamides were determined. The maximal
concentrations for the sum of alkamides in human plasma were reached within 2.3 h post ingestion
and averaged 336 +/- 131 ng eq/ml plasma. No obvious differences were observed in the
pharmacokinetics in 2 additional fasted subjects. This single dose study provides evidence that
alkamides are orally available and that their pharmacokinetics are in agreement with the one dose
three times daily regimen already recommended for
Echinacea
.
Studies of transport of alkamides trough a cultured monolayer of colonic cells (Jager et al. 2000) were
performed on human adenocarcinoma colonic cell line Caco-2 (ATCC) as a model to assess the
epithelial transport of dodeca-2 E,4 E,8 Z,10 E/ Z-tetraenoic acid isobutylamides. 30 minutes after
apical loading of 25 microg/ml, about 15% of these alkamides were detectable on the basolateral side.
Close monitoring of the transport during 6 hours revealed a nearly complete transport to the
basolateral side after 4 hours and no significant metabolism was observable. Transport experiments
performed at 4
o
C showed only a slight decrease in transport, which is a strong hint that dodeca-2 E,4
E,8 Z,10 E/ Z-tetraenoic acid isobutylamides cross biological membranes by passive diffusion. Nearly
the same results were obtained after preincubation of the Caco-2 cells with lipopolysaccharides (LPS)
or phorbol 12-myristate-13-acetate (PMA) to mimic an inflammatory status. These results support the
assumption that the alkamides can be easily transported from the intestinum and hence may contribute
to the
in vivo
effects of
Echinacea
preparations.
Permeability of alkylamides and caffeic acid conjugates trough Caco-2 cell monolayer model was
studied again in 2004 (Matthias et al. 2004). Caffeic acid conjugates (caftaric acid, echinacosides and
cichoric acid) permeated poorly through the Caco-2 monolayers although their potential metabolite,
cinnamic acid, diffused readily with apparent permeability of 10
-4
cm/s. Alkylamides were found to
diffuse with apparent permeability ranging from 3* 10
-6
to 3* 10
-4
cm/s. Compounds with apparent
permeability is considered to > 1* 10
-6
, are considered to have almost complete intestinal absorption.
Alkamide content in plasma samples obtained from a randomized, open, single-dose, crossover study
after oral administration of a 60% ethanolic extract from the roots of
E. angustifolia
to 11 healthy
subjects was analysed by liquid chromatography electrospray ionization ion-trap mass spectrometry
(Woelkart et al. 2005). The maximum concentration of dodeca-2E,4E,8Z,10E/Z-tetraenoic acid
isobutylamides, the main alkamides in the roots of
E. angustifolia
, appeared already after 30 minutes
and was 10.88 ng/ml for the 2.5-ml dose.
Matthias et al. (2005b) have investigated the metabolism of the alkylamides by human liver
microsomes. No significant degradation of alkylamides was evident in cytosolic fractions. Time- and
NADPH-dependent degradation of alkylamides was observed in microsomal fractions suggesting they
are metabolised by cytochrome P450 (P450) enzymes in human liver. Pure synthetic 2-ene
alkylamides inhibited the degradation of 2,4-diene alkylamides. These findings suggest that
Echinacea
may affect the P450-mediated metabolism of other concurrently ingested pharmaceuticals.
The dose-dependent pharmacokinetics of caffeic acid was studied on rabbits (Uang & Hsu 1997).
Three different doses (5, 10 and 25 mg/kg) were administered intravenously to six rabbits each. The
concentration-time profiles for caffeic acid could be fitted by a two-compartment model for each dose.
The results showed that total-body clearance and elimination rate constant from the central
compartment (k10) after a 5 mg/kg dose were greater than those after the other two doses.
Furthermore, the terminal elimination half-life (beta half-life) and mean residence time (MRT) after a
5 mg/kg dose were less than after the other doses. The AUC value increased linearly with dose within
the range of 10-25 mg/kg. Most of the unchanged caffeic acid was excreted in the urine within 2 h.
©
EMEA 2008
10/35
The percentage of unchanged caffeic acid excreted in the urine was 63, 60, and 55% after doses of 5,
10 and 25 mg/kg, respectively, which was not significantly different. However, significant differences
in the renal clearances and renal excretion rate constants were observed with a 5 mg/kg dose compared
to the other doses. On the other hand, nonrenal clearances and nonrenal excretion rate constants
showed no dose-related differences. The differences observed in total-body clearance, k10, beta half-
life, and MRT between a 5 mg/kg dose and the other doses can be explained on the basis of the
differences in renal clearance and renal excretion rate constants.
2.2
Pharmacodynamics
2.2.1
Animal studies
Immunomodulatory effect
Several different candidate substances from
Echinacea
have been identified that may contribute to its
immunomodulatory effects, including polysaccharides of various sizes, caffeic acid derivatives,
alkamides and melanins. The most studied compounds are the polysaccharides, with supporting
evidence coming from studies conducted both in vitro and in vivo. Research on the alkamides also
indicates a major role for these compounds. Less evidence exists for the immunostimulatory actions of
the caffeic acid derivatives. It is very likely that a combination of these and other unknown agents
contribute to the overall therapeutic activity of
Echinacea
products.
Polysaccharides
Echinacea
polysaccharides were isolated from aerial parts and roots of
E. purpurea
. Further
purification yielded a protein-free preparation called EPS (Stimpel et al. 1984) and two
polysaccharides; PSI, 4-O-methylglucuronoarabinoxylan (35,000 Da) and PSII, a 50,000 Da acidic
arabinorhamnogalactan (Proksch & Wagner 1987). These polysaccharides did not influence
in vitro
T
and B cell proliferation or cytokine production but instead affected the
in vitro
phagocytosis,
chemotaxis, and production of cytokines observed in granulocytes and macrophages (Stimpel et al.
1984; Wagner et al. 1985). These polysaccharides also enhanced the cytotoxic action of macrophages
toward tumor P815 cells (Stimpel et al. 1984). Later work repeated and extended earlier studies by
using an arabinogalactan isolated from
E. purpurea
grown in tissue culture (Wagner et al.-, 1988).
This polysaccharide enhanced macrophage activation and intracellular killing of
Leishmania enriettii
(Luettig et al. 1989).
The concentrations of
Echinacea
polysaccharides required to obtain the
in vitro
effect on immune cells
discussed above were extremely high. In studies using EPS (Stimpel et al. 1984) concentrations of
1,000 microg/ml were required to enhance macrophage cytotoxicity. In addition, this high
concentration of EPS was required to enhance macrophage IL-1 production to levels 50% of those
achieved using maximal concentrations of Salmonella lipopolysaccharide (LPS). Concentrations
250 microg/ml of the purified arabinogalactan isolated from cultures of suspension cells of
E.
purpurea
(Wagner et al. 1988) were required to enhance macrophage production of cytokines to levels
equal to (interferon-beta) or 20% (IL-1) of those achieved with maximal concentrations of
E. coli
lipopolysaccharide (10 microg/ml).
Animal studies using i.v. EPS demonstrated enhanced phagocytosis (Wagner et al. 1985).
Arabinogalactan injected i.v. into mice exhibited enhanced resistance against systemic infections with
Listeria monocytogenes
and
Candida albicans
in both normal (Roesler et al. 1991) and
immunocompromised (Steinmuller et al. 1993) animals. Oral administration of a polysaccharide
fraction from
E. purpurea
aerial parts had no effect on lung macrophage function in normal rats (Goel
et al. 2002). Polysaccharides purified from
E. purpurea
tissue culture injected i.v. into patients
undergoing chemotherapy for gastric cancer showed a lessening of leucopoenia (Melchart et al. 2002).
Caffeic Acid Derivatives
Cichoric acid is present in roots of
E. purpurea
(0.6%-2.1%) and aerial parts of
E. purpurea
,
E.
angustifolia
and
E. pallida
at concentrations of 1.2-3.1% (Bauer et al, 1988b). In an
in vitro
©
EMEA 2008
11/35
granulocyte assay, cichoric acid concentrations between 10 and 100 ng/ml caused strong stimulation
of phagocytosis and in mice it enhanced carbon clearance (Bauer et al, 1989).
Echinacoside is not present in
E. purpurea
root or aerial parts (Bauer et al, 1988b; Pietta et al. 1998).
Alkamides
The major lipophilic components of
Echinacea
are the alkamides. The aerial parts of all three species
contain alkamides (Bauer et al. 1988b). Fifteen major alkamides were identified in roots of
E.
angustifolia
and 11 in
E. purpurea
roots (Bauer et al. 1988b).
The following studies were performed to determine if the phagocytic activity exhibited by extracts
from
Echinacea
was predominantly due to polar or non-polar compounds. Ethanolic extracts from all
three species and from both roots and aerial parts were separated into a polar (water) and non-polar
(chloroform) fraction. The fractions were tested for phagocytosis in the granulocyte smear test (
in
vitro
) and carbon clearance (
in vivo
). In essentially every case the non-polar (chloroform) fractions
were the most active (Bauer et al. 1988a; Bauer et al. 1989). A further purified non-polar fraction
enriched for alkamides (isolated from
E. purpurea
and
E. angustifolia
roots) enhanced phagocytosis in
the carbon clearance test by 1.5 to 1.7 fold (Bauer et al. 1989).
A purified alkamide fraction administered orally to rats was found to enhance the phagocytic activity
and phagocytic index of lung alveolar macrophages. In addition, alveolar macrophages collected from
alkamide-treated rats produced more TNF-alpha and nitric oxide after stimulation with LPS in vitro
(Goel et al. 2002). The upregulation of TNF-alpha mRNA by
Echinacea
alkylamides was found to be
mediated by cannabinoid receptor CB2, increased cAMP, p38/MAPK and JNK signalling, as well as
NF-jB and ATF-2/CREB-1 activation (Gertsch et al. 2004).
Melanin
This new active constituent of
Echinacea purpurea
was purposed recently (Pasco et al. 2005, Pugh et
al. 2005).
It was shown that melanin is an immunostimulatory compound that is a major component of
immunostimulant medicinal plants. While melanin is present in commonly consumed vegetables, its
specific activity is several orders of magnitude less than melanin extracted from these medicinal
plants. The major reason that this agent has eluded detection is its solvent-specific requirement for
extraction/solubility. Ingestion of melanin by mice for four days increases production
ex vivo
of
interferon-gamma by spleen cells and IgA and interleukin-6 by Peyer's patch cells. The isolated
melanin was an amorphous dark colour pigment (reddish brown and similar to pheomelanin), general
insoluble in most solvents, bleaching by oxidizing agents (H
2
O
2
), and pheomelanin-like solubility in
alkali and phenol. Elemental analysis indicated about 50% carbon, about 13% nitrogen, about 7%
hydrogen, about 0.8% sulphur and about 0.08% phosphorus. NF-kappa B/luciferase reporter gene
based monocite activation assay was used to screen for immunomodulatory activities of extracts. The
EC50 value for
Echinacea
melanin was 1 microg/ml with maximal activation occurring at 10
microg/ml. Maximal activation with this melanin is equal to that of maximally activating
concentrations of
E. coli
LPS (10 microg/ml). Monocyte activation by
Echinacea
melanin
substantially increased the expression of cytokine mRNAs characteristic of this state.
Echinacea
melanin induced IL-1 mRNA expression to the same extent as maximally activating concentrations of
LPS.
Juice, extract, crude fractions
Treatment with 1.0 or 5.0 mg/ml of lyophilised expressed juice of
Echinacea purpurea
(Echinacin)
induced a dose-dependent and highly significant increase (p<0.001) in the percentage of
phagocytosing granulocytes from 79% to 95% and stimulated the phagocytosis of yeast particles
significantly (p<0.01) about 50%. With the highest tested dose of 12.5 mg/ml both the number of
phagocytosing granulocytes and the phagocytosis index decreased (Stotzem et al. 1992). Also the
phagocytosis of isolated peritoneal macrophages from mice and macrophages of the isolated perfused
rat liver was significantly stimulated after i.p. and/or p.o. application of
Echinacea purpurea
expressed
juice.
The dry residue of an ethanolic tincture (1:10) showed a maximum phagocytosis stimulation of 33% in
the
in vitro
granulocyte test in the concentration of 0.001%. Higher dilutions did not show any effect
(Bauer et al. 1988a). In the
in-vivo
carbon clearance test on mice p.o. administration of 0.5 ml
©
EMEA 2008
12/35
Echinacea
extract in 30 ml isotonic saline solution over 3 days leads to 3-fold increased phagocytosis
in relation to the control group.
The water-soluble fraction increases the carbon clearance by the factor 1.9 (Bauer et al. 1988a, Bauer
et al. 1989) and the lipophilic alkamide fraction by the factor 1.7. In the granulocyte test the water-
soluble fraction (10
-3
%) causes a 42% phagocytosis stimulation and the chloroform fraction (10
-3
%)
37%.
In vitro
and
in vivo
phagocytosis stimulation could be proven for the ethanolic extract and the mother
tincture. The carbon clearance test of an extract, manufactured from the herb with ethanol (1:10),
showed on mice after p.o. application an increased coal elimination by the factor 1.4 in relation to
control. The chloroform-soluble fraction was stronger (factor 2.1); the water-soluble fraction was
weaker (factor 1.3) (Bauer et al. 1989). A mother tincture of
Echinacea purpurea
, manufactured
according the German homoeopathic pharmacopoeia, stimulated in a dosage of p.o. 3 times daily
0.17 ml/kg kg over 2 days the carbon clearance around the factor 2.1.
The immunostimulating effect of
Echinacea purpurea
was studied on natural killer (NK) cells since
these cells are active in spontaneous, non-specific immunity against neoplasms and virus-mediated
infections (Currier & Miller 2000). Aging mice was selected as a model animal, since at this stage of
life, like humans, the above-mentioned afflictions increase in frequency. It was previously found that
neither the cytokine, interleukin-2, nor the pharmacological agent, indomethacin, both potent
stimulators of NK cell numbers/function in younger adult mice, is effective in stimulating NK cells in
elderly mice. The study of Currier & Miller (2000) was designed to assess the numbers/production of
NK cells in the spleen and bone marrow of aging, normal mice, after
in vivo
dietary administration of
E. purpurea
(14 days), or, after injection of thyroxin, a stimulant of NK cell function (10 days).
Immunoperoxidase labelling techniques, coupled with haematologic tetrachrome staining were used to
identify NK cells in both the spleen (primary site of NK cell function) and the bone marrow (site of
NK cell generation). Double immunofluorescence staining, employing propidium iodide, was used to
assess NK cell lytic function. The results revealed that
E. purpurea
, but not thyroxin, had the capacity
to increase NK cell numbers, in aging mice, reflecting increased new NK cell production in their bone
marrow generation site, leading to an increase in the absolute numbers of NK cells in the spleen, their
primary destiny. The
E. purpurea
-mediated increase in NK cell numbers was indeed paralleled by an
increase in their anti-tumor, lytic functional capacity.
The mechanism of activation of human peripheral blood NK cells by
Echinacea
water soluble extracts
was studied (Gan et al. 2003). The study examined
in vitro
the effects of soluble extracts of
E.
purpurea
on natural killer (NK) cells present in human peripheral blood mononuclear cells (PBMC).
Flow cytometric methods were used to examine activation, cytotoxicity, NK-target binding, and killer
cell frequency. Treatment of PBMC with
Echinacea
overnight resulted in the activation of CD69
expression and increase in mean fluorescence intensity in both the CD16+ and CD16+CD56+ NK
subsets. However, the frequency of CD16+ cells was decreased as well as the mean fluorescence
intensity was down-regulated. NK cytotoxicity was increased 100% at the concentration of 0.1
microg/ml of
Echinacea
in a short time (4 h) assay. At the single cell level the frequency of CD56+
NK-target conjugates increased and a plateau was reached after 30-60 min of incubation. Likewise, the
frequency of CD56+ killer cells in the conjugates was also significantly increased by
Echinacea
.
There was recruitment of non-conjugated CD56+ cells into CD16+ NK-target conjugates and
activation of the NK-target non-killer conjugates into killer cells.
Antimicrobial effect
Cichoric acid from
Echinacea purpurea
expressed juice was found to reduce a yield of VSV
(Vesicular Stomatitis virus) in mouse L-929-cells. 125 microg/ml cichoric acid after 4 h incubation
reduced the infectivity of VSV by more than 50% (Cheminat et al. 1988). For trideca-1,11-dien-
3,5,7,9-tetrain and trideca-1-en-3,5,7,9,11-pentain, both main alkylamides from
Echinacea purpurea
, a
bacteriostatic and fungistatic effect is described. Total growth inhibition of
Escherichia coli
was found
in concentrations of 100 and/or 50 microg/ml, against
Pseudomonas aeruginosa
with a concentration
of 5.0 and/or 1,000 microg/ml (Schulte et al. 1967a, Schulte et al. 1967b). For both constituents the
following inhibiting concentrations were determined:
Aspergillus niger
>0.01% and/or 0.1%;
Candida
©
EMEA 2008
13/35
albicans
0% and/or 0.2%;
Staphylococcus aureus
0.005% and/or 0.01%;
Pseudomonas aeruginosa
0.005% and/or 0.1% and
Escherichia coli
0.0005% and/or 0.005% (Reisch et al. 1967).
For the first time Orinda et al. (1973) reported about a virustatic effect of an
Echinacea
expressed
juice. He showed that expressed juice in presence of DEAE Dextran mouse-L-929 cells protected
against the cytopathic effect of Encephalomyocarditis virus (EMC virus) and Vesicular Stomatitis
virus (VSV). The virustatic effect was quantitatively measured by 2 methods (Wacker & Hilbig 1978):
the Plaque reduction method in the cell culture and the colour method by Finter. The extract of
Echinacea purpurea
was fractionated by TLC and the virustatic activity of the fractions was tested.
The virustatic activity was distributed to all fractions of the entire TLC. The antiviral principle could
not be inactivated by a two-hour treatment at 60 to 80°C.
Both a decoction and a 30% ethanolic extract of
Echinacea purpurea
inhibits the intracellular
propagation of ECHO9 HILL virus in a monkey kidney cell culture. A 50% virus inhibition was still
observed with dilution rates between 1:6 to 1:15 (Skwarek et al. 1996).
Isobutylamides and polyacetylenes from
Echinacea purpurea
have phototoxic antimicrobial activity
against fungi, including clinically relevant pathogenic fungi. A hexane extract of
Echinacea
inhibit
growth of yeast strains of
Saccharomyces cerevisiae, Candida shehata, Candida kefyr, Candida
albicans, Candida steatulytica
and
Candida tropicalis
under near UV irradiation (phototoxicity) and
to a lower extent without irradiation in the conventional antifungal activity (Binns et al. 2000).
Other effects
The healing of standardised, surgery made skin wounds on guinea pigs was accelerated by
Echinacea
ointment (Kinkel et al. 1984). The wound area at 6. and 9. day after surgery was significantly (p<0,05)
smaller than those of the untreated control animals. In comparison with the control group, the clinical
picture was significantly improved in the group treated with
Echinacea
ointment already on day 3
(p<0,05).
10 and/or 30 microlitre of an extract from
Echinacea purpurea
fresh plants, manufactured with 90%
ethanol, (final ethanol concentration 65%), with a dry residue of 10.5 mg/ml, significantly inhibited
the concentration of collagen lattices populated with C3H10T1/2-fibroblasts
in vitro
. Ethanol of equal
concentration did not have influence. Dependent on the time of the addition of the extract the
elongation of fibroblasts and the cell processes leading to the cross-linking of the collagen were
inhibited. If the extract was applied 1 h after the beginning of cross-linking, no more influence could
be determined. The authors discussed the significance of these observations in relation to the process
of wound healing (Zoutewelle & Van Wijk 1990).
Echinacea
-Fibrin grafts stimulated the healing
tendency in guinea pig. Compared with pure fibrin grafts, healing tendency of the wound areas
increased and less marked leucocytic infiltration were observed in
Echinacea
-Fibrin grafts
(Tünnerhoff & Schwabe 1956).
Caffeic acid derivates protected collagen from free radical-induced degradation in a dose dependent
manner; the IC50 for cichoric acid was 16.5 microM (Maffei Facino 1995).
The radical scavenging activity of
Echinacea
methanolic extracts and isolated phenolic compounds
was evaluated
in vitro
with a spectrophotometric method based on the reduction of an alcoholic 2,2-
diphenyl-1-picrylhydrazyl (DPPH) radical solution at 517 nm in the presence of a hydrogen donating
antioxidant (Pellati et al. 2004). Among the pure compounds, echinacoside had the highest capacity to
quench DPPH radicals (EC50 = 6.6 microM), followed by cichoric acid (8.6 microM) and cynarin
(11.0 microM). Chlorogenic acid, caffeic acid and caftaric acid had lower activity (18.9 microM, 19.1
microM and 20.5 microM, respectively).
The average EC50 values for E.
purpurea, E. pallida
and
E. angustifolia
were 134, 167 and
231 microg/ml, respectively.
Dried pressed juice from
Echinacea purpurea
whole plants significantly (p< 0.05) elevates a SOD
(superoxide dismutase) activity when given to a mice in a dose of 360 mg/kg every other day for 3
weeks (Mishima et al. 2004).
Alkamides from the roots of
Echinacea purpurea
were examined for anti-inflammatory activity in an
in vitro
model system (Clifford et al. 2002). Cyclooxygenase-I (COX-I) and cyclooxygenase-II (COX-
©
EMEA 2008
14/35
II) inhibitory activities were assessed at pH 7 for alkamides isolated from
E. purpurea
roots to
compare inhibitory activities between the two cyclooxygenase isozymes. At 100 microg/ml, several
E.
purpurea
alkamides inhibited COX-I and COX-II enzymes in the range of 36-60% and 15-46%,
respectively, as compared to controls.
5-lipoxygenase-inhibiting activity of extracts of five wild and three commercially used species of the
genus
Echinacea
were investigated to characterise anti-inflammatory activity of
Echinacea
(Merali et
al. 2003). The inhibition of the 5-lipoxygenase (5-LOX) enzyme of the arachadonic acid pathway was
determined by HPLC detection of a direct metabolic product (LTB4) of 5-LOX derived from
stimulated rat basophilic cells. Root extracts of the three commercial species of
Echinacea
(
E.
purpurea, E. pallida var. angustifolia, E. pallida var. pallida
) inhibited the 5-LOX enzyme.
Mosquitocidal activity was assessed at 100 and 10 microg/ml, with 100% mortality against
Aedes
aegyptii
larvae noted for several
E. purpurea
alkamides at 100 microg/ml.
2.2.2
Human studies
Addition of 1.0 or 5.0 mg/ml of lyophilised expressed juice of
Echinacea purpurea
(Echinacin) to
human blood
in vitro
induced a dose-dependent and highly significant increase (p<0.001) in the
percentage of phagocytosing human granulocytes from 79% to 95% and stimulates the phagocytosis
of yeast particles significantly (p<0.01) about 50%. With the highest tested dose of 12.5 mg/ml both
the number of phagocytosing granulocytes and the phagocytosis index decreased (Stotzem et al.
1992).
Influence of
Echinacea purpurea
on % of phagocytosing human granulocytes in vitro (mean +/- SD).
* significant difference as compared with control. p < 0.001 (Stotzem et al. 1992).
Regulation of human immune gene expression as influenced by a commercial blended
Echinacea
product was studied (Randolph et al. 2003).
Echinacea
preparation was given to healthy volunteers
and gene expression in their blood cells was examined. Additionally, gene expression in human
immune cells (THP-1) were exposed to
Echinacea
extracts (250 microg/ml)
in vitro
was studied. Gene
expression was studied by measuring the amount of respective mRNA with quantitative PCR.
Expression of interleukin-1alpha, interleukin-1beta, TNF-alpha, intracellular adhesion molecule,
interleukin-8 and interleukin-10 genes increased up to 10-fold in
Echinacea
treated THP-1 cells.
In
vivo
, many lymphokines were down regulated, but the expression of interferon-alpha steadily rose,
consistent with an antiviral response.
The results of this study are consistent with the results of an older study, where the cytokine
production by normal human peripheral blood macrophages at
in vitro
stimulation with commercial
preparations of
Echinacea
was measured with ELISA (Burger et al. 1997).
Echinacea
stimulated
immune cells produced significantly higher amount of interleukin-1, TNF-alpha, interleukin-6 and
interleukin-10.
©
EMEA 2008
15/35
Echinacea
herb and root powders were also found to significantly enhance the viability and/or
proliferation of human peripheral blood mononuclear cells
in vitro
(Rininger et al. 2000).
Stimulation of phagocytic activity and production of cytokines by oral application of a commercially
available
Echinacea
preparation was also studied in humans
in vivo
(Schwarz et al. 2002). Forty
healthy male volunteers (ages 20-40 years) participated in the study. They received either a freshly
expressed juice of
Echinacea purpurea
herbs or placebo juice using a double-blind placebo-controlled
crossover design with two treatment periods of 14 days and a wash-out period of 4 weeks in between.
Endpoints for immune stimulation were phagocytic activity of polymorphonuclear leukocytes and
monocytes measured by flow-cytometry, production of tumor necrosis factor alpha (TNF-alpha) and
interleukin-1beta (IL-1beta) by LPS-stimulated blood monocytes.
Echinacea purpurea
herbs did
neither enhance phagocytic activity of polymorphonuclear leukocytes nor that of monocytes when
compared with placebo. Similarly as in the study of gene expression (Randolph et al. 2003) also in this
study the production of TNF-alpha and IL-1beta by immune cells isolated from volunteers treated with
Echinacea purpurea
herbs did not increase.
Echinacea purpurea
herbs decreased serum ferritin
concentration (p = 0.0005). All other laboratory and safety data remained unchanged.
Ability of
Echinacea purpurea
to prevent or to relieve experimental infection with rhinovirus type 39
(RV-39) was evaluated in a randomised, double-blind, placebo-controlled clinical trial (Sperber et al.
2004). Forty-eight previously healthy adults received
Echinacea
or placebo, 2.5 ml 3 times per day,
for 7 days before and 7 days after intranasal inoculation with RV-39. Symptoms were assessed to
evaluate clinical illness. Viral culture and serologic studies were performed to evaluate the presence of
rhinovirus infection. A total of 92% of
Echinacea
recipients and 95% of placebo recipients were
infected. Colds developed in 58% of
Echinacea
recipients and 82% of placebo recipients (p = 0.114,
by Fisher's exact test). Administration of
Echinacea
before and after exposure to rhinovirus did not
significantly decrease the rate or the severity of infection; however, the trend of beneficial effect of
Echinacea
was shown in nearly all measured parameters: mean score of sore throat was 1.04 in
Echinacea
group and 2.45 in placebo group, mean score of congestion was 1.87 in
Echinacea
group
and 2.66 in placebo group, mean score of headache was 0.63 in
Echinacea
group and 0.92 in placebo
group. Mean total symptom score was lover in
Echinacea
group than in placebo group on every
individual day of the trial.
Similarly, effectiveness of
Echinacea
for prevention of experimental Rhinovirus colds was not
statistically significant in an earlier study (Turner et al. 2000). Infection occurred in 44 and 57% and
illness occurred in 36 and 43% of the
Echinacea
- and placebo-treated subjects, respectively.
2.3
Interactions
No pharmacodynamic or pharmacokinetic drug interactions of whole
Echinacea purpurea
herb extract
or isolated constituents have been reported in humans (ESCOP, WHO, Komission E). Theoretically it
can be expected, that
Echinacea
preparations can interact with immunomodulatory therapy
(immunostimulatory and immunoinhibitory). However, no clinical cases of drug interactions have
been reported (Izzo & Ernst 2001).
In
in vitro
test
E. purpurea
demonstrated mild inhibition of CYP3A4 activity with 7- benzyloxy-4-
trifluoromethylcoumarin as the model substrate, but mild inducing effects in the presence of the model
substrate resorufin benzyl ether. Little effect on CYP2D6 and moderate inhibition of CYP2C9 was
seen with
E. purpurea
(Yale & Glurich 2006).
Clinical trial using 12 healthy volunteers (6 women, 6 men) revealed that the effects of
E. purpurea
root
on CYP activity were minor (Gurley et al. 2004).
In another trial on 12 healthy volunteers
Echinacea purpurea
root
administration significantly
increased the systemic clearance of midazolam by 34%, and significantly reduced the midazolam area
under the concentration-time curve by 23%. In contrast, the oral clearance of midazolam was not
significantly altered. The oral availability of midazolam after
Echinacea
dosing was significantly.
Hepatic availability and intestinal availability were significantly altered in opposite directions.
Echinacea
dosing significantly reduced the oral clearance of caffeine. The oral clearance of
©
EMEA 2008
16/35
tolbutamide was reduced by 11%. The oral clearance of dextromethorphan in 11 CYP2D6 extensive
metabolizers was not affected by
Echinacea
dosing.
E. purpurea
root reduced the oral clearance of
substrates of CYP1A2 but not the oral clearance of substrates of CYP2C9 and CYP2D6.
Echinacea
selectively modulates the catalytic activity of CYP3A at hepatic and intestinal sites. The type of drug
interaction observed between
Echinacea
and other CYP3A substrates will be dependent on the relative
extraction of drugs at hepatic and intestinal sites (Gorski et al. 2004).
Ethanolic extracts from fresh
Echinacea purpurea
and
Spilanthes acmella
and dried
Hydrastis
canadensis
were examined with regard to their ability to inhibit cytochrome P450(2E1) mediated
oxidation of p-nitrophenol in vitro. In addition, individual constituents of these extracts, including
alkylamides from
E. purpurea
and
S. acmella
, caffeic acid derivatives from
E. purpurea
, and several
of the major alkaloids from
H. canadensis
, were tested for inhibition using the same assay.
H.
canadensis
(goldenseal) was a strong inhibitor of the P450(2E1), and the inhibition appeared to be
related to the presence of the alkaloids berberine, hydrastine and canadine in the extract. These
compounds inhibited 2E1 with K(I) values ranging from 2.8 microM for hydrastine to 18 microM for
berberine. The alkylamides present in
E. purpurea
and
S. acmella
also showed significant inhibition at
concentrations as low as 25 microM, whereas the caffeic acid derivatives had no effect. Commercial
green tea preparations, along with four of the individual tea catechins, were also examined and were
found to have no effect on the activity of P450(2E1) (Raner et al. 2007).
3
Clinical Efficacy
3.1
Clinical studies
Most of the clinical studies are related to the immunological effect and recurrent infections of the
upper respiratory tract.
©
EMEA 2008
17/35
Table 1: The list of the placebo-controlled clinical studies with p.o. use of expressed juice of
Echinacea purpurea
herb on the treatment of recurrent infections
of the upper respiratory tract. These studies were used to asses the indications, posology and safety.
authors,
year
patients
(age)
indication
formulation
Dose (mode of
administration)
control
efficacy
safety
comment
Yale &
Liu 2004
128 (18-62
years)
Treatment of the common
cold
freeze-dried pressed juice
from the aerial portion of
E. purpurea
100 mg 3 times per day
placebo
Not significant
well tolerated
lower dosing
than in other
trials
Hoheisel
et al. 1997
120 (38 ±
11 years)
Treatment of URTI
“first signs of cold”
“justifiable initial signs of
acute upper respiratory
infection”
E. purpurea
expressed
juice, (Echinagard)
20 drops (1-2 ml) every 2
hours for the first day and
thereafter three times
daily.
(in half glass of water)
Placebo
“identical in color
and ethanol
concentration”
Significant:
median
time taken to
improvement was 4
days (
Echinacea
) and 8
days (placebo)
No specific adverse
events. Tolerability of
placebo and
Echinacea
was equal.
Schulten
et al. 2001
80 (39 ± 12
years)
Treatment of URTI
“incipient infection of
upper respiratory tract
(subjective sensation of
having a cold and at least
one of the following
symptoms: sneezing,
rhinorrhea, congestion of
the nose, sore throat,
cough, headache, malaise,
chilliness”
E. purpurea
, (Echinacin,
EC3lJO) pressed juice
from fresh flowering
purple coneflower
(1.7-2.5:1). stabilised by
ethanol.
5 ml twice daily
Placebo
“indistinguishable
in terms of
appearance, taste,
smell, colour and
packaging”
Significant:
In
Echinacea
the median
time of illness was 6
days and in placebo 9
days
well tolerated
Taylor et
al. 2003
407
children
(5.5 ± 2.7
years
Treatment of URTI
E. purpurea
herba dried
expressed juice (extract?),
(31-54:1) dissolved to
give 1:1 extract.
3.75 ml twice daily for
children 2 to 5 years old
and 5 ml twice daily for
children 6 to 11 years old.
placebo “was
identical in
appearance and
similar in taste and
smell”
Not significant
no difference in overall
rate of adverse events,
rash occurred in 7.1%
in
Echinacea
and 2.7%
in placebo
dosage is not
clear, the
product was not
standardized,
late beginning of
treatment
©
EMEA 2008
18/35
Table 2: The list of other clinical studies with expressed juice or extract of
Echinacea purpurea
herb or combinations on the immunological effect. This
studies were used for assessment of safety.
authors,
year
appl. patients
(age)
indication
formulation
dose
control
efficacy
safety
comment
Turner et al.
2000
p.o.
117
prevention of
experimental
rhinovirus colds
not clear (contained
0.16% cichoric acid
with almost no
echinacosides or
alkamides)
300 mg 3 times
daily
placebo
Not significant, but
important trend:
Infection occurred in
44 and 57% and
illness occurred in 36
and 43% of the
Echinacea
- and
placebo
No side effects
were observed
prevention,
unknown
species
Sperber et
al. 2004
p.o.
48 (18-64
years)
Prevention of
experimental
rhinovirus colds
E. purpurea
herba
expressed juice,
2.5 ml 3 times per
day
placebo
Not significant, but
important trend:
Colds in 58% of
Echinacea
and 82%
of placebo
Not different to
placebo
prevention,
poor
statistical
power
Grimm &
Müller 1999
p.o.
108 (40 ±
16 years)
Prevention of URTI
E. purpurea
fluid
extract, (Echinacin-
Liquidum)
4 ml twice daily
placebo
Not significant, but
important trend:
The average number
of colds and
respiratory infections
per patient was 0.78
in the
Echinacea
group, and 0.93 in the
placebo group.
Side effects were
observed in 20%
of
Echinacea
group and in 13%
of placebo group.
The majority of
adverse events was
mild and transient.
prevention
Baetgen
1984
i.m.
170
children
(0-13
years)
Treatment of pertusis
Echinacin
2 ml/day in
children
1 ml/day in infants
active
(antibiotic)
No statistical
analisys.
reduction of disease
in 34% of patients in
Echinacea
group and
in 10% in antibiotic
group
well tolerated
©
EMEA 2008
19/35
authors,
year
appl. patients
(age)
indication
formulation
dose
control
efficacy
safety
comment
Baetgen
1988
i.m.
1280
children
(0-19
years)
Treatment of URTI
Echinacin (Madaus)
2 ml/day in
children
1 ml/day in infants
active
(antibiotic)
No statistical
analisys.
reduction of disease
in 46% of patients in
Echinacea
group, in
16% in antibiotic
group
and in 25% in
patients receiving
combination of
Echinacea
and
antibiotic.
“The injections
with Echinacin
were remarkably
well tolerated”
Barrett et al.
2002
p.o.
148
students
Treatment of URTI
E. purpurea
herb (25%)
and root (25%) an
E.
angustifolia
root (50%)
provided by Shaklee
Tecnica (Pleasanton,
California)
4 capsules
(containing 247 mg
of
Echinacea
) 6
times during the
first 24 hours of the
study, and then 4
capsules
3 times daily.
placebo
Not significant
Not different to
placebo
mixture of 2
species
Heinen-
Kammerer
et al. 2005
p.o.
995
treatment of chronic
recurrent respiratory
disease
E. purpurea
fluid
extract, (Echinacin)
standard
therapy
The risk of recurrent
illnes was 2.3 fold
lower and the
duration of relapse
1.4 days shorter in
Echinacea
group
non-
randomised
study
Lindenmuth
&
Lindenmuth
2000
p.o.
95
early symptoms of
cold or flu
Herbal tea (
Echinacea
species?)
5 to 6 cups per day placebo
significant
difference
between the
Echinacea
and
placebo for all 3
questions measured
(efficacy, number of
days the symptoms
lasted, and number of
days for change): p <
0.001
no negative effects
reported by any of
the subjects in
either group
©
EMEA 2008
20/35
authors,
year
appl. patients
(age)
indication
formulation
dose
control
efficacy
safety
comment
Melchart et
al. 2002
i.v.
50
counteraction of the
undesired effects of
chemotherapy
fraction isolated from
the
Echinacea purpurea
herb cell cultures
2 mg of
polysaccharides per
day
matched
historical
controls
53% increase in
median number of
leukocytes, no effects
on phagocytic
activity of
granulocytes or on
lymphocyte
subpopulations
Sixty-eight adverse
events including
two deaths were
observed, most
likely due to
chemotherapy and
the general
condition of the
patients
open
prospective
study with
matched
historical
controls
Vonau et al.
2001
50
recurrent genital
herpes
extract of
Echinacea
purpurea
(Echinaforce)
placebo
(cross-over)
Not statistically
significant
Brinkeborn
et al. 1999
p.o.
246 (41 ±
14 years)
Treatment of URTI
“immediately after the
onset of the first
symptoms of common
cold”
E. purpurea
95% herba,
5% radix, dry extract
(Echinaforce)
3 times daily 2
tablets containing
6.78 mg of extract.
Placebo
“could almost
not be
distinguished
bz smell or
taste”
Significant:
index of
12 symptoms reduced
for 63% in
Echinacea
and for 29% in
placebo
Treatments were
well tolerated. In
Echinacea
group
the frequency of
adverse events was
not significantly
higher than in the
placebo group.
Goel et al.
2004
p.o.
282 (18 –
65 years)
Treatment of URTI
“first symptoms of
related to common
cold… A cold is the
recent onset of
unexplained tiredness
(fatigue), muscle aches
and pains that are not
related to … You may
also get headaches,
feel feverish and get
chills with or without
fever…”
water-ethanol extract of
fresh herbs of
E.
purpurea
containing
0.25 mg/ml of
alkamides, 2.5 mg/ml of
cichoric acid and 25
mg/ml of
polysaccharides
(Echinilin, Natural
Factors Nutritional
Products, ind.
Vancouver, BC,
Canada)
4 ml 10 times per
day on first day and
4 ml 4 times per
day for next 6 days.
placebo
Significant:
total
daily symptom scores
were 23.1% lower in
the
Echinacea
than in
placebo
Not different to
placebo
©
EMEA 2008
21/35
3.1.1
Placebo-controlled trials on
E. purpurea
expressed juice for treatment of URTI
Yale & Liu (2004)
tested the efficacy of a standardized preparation of
E. purpurea
in reducing
symptom severity and duration of the common cold, in a randomised, double-blind, placebo-controlled
trial recently. 128 patients received either 100 mg of freeze-dried pressed juice from the aerial portion
of
E. purpurea
or a lactose placebo 3 times daily until cold symptoms were relieved but not longer
than 14 days. Symptoms (sneezing, nasal discharge, nasal congestion, headache, sore or scratchy
throat, hoarseness, muscle aches, and cough) were scored subjectively by the patient and recorded
daily. Patients were enrolled within 24 hours of cold symptom onset. No statistically significant
difference was observed between treatment groups for either total symptom scores (P range, 0.29-
0.90) or mean individual symptom scores (P range, 0.09-0.93). The time to resolution of symptoms
was not statistically different (P = 0.73).
Hoheisel et al. (1997)
carried out a randomised double-blind placebo-controlled trial on 120 patients
with initial symptoms of acute, uncomplicated upper airways infection. The peroral treatment with
either
Echinacea purpurea
expressed juice or placebo lasted for up to 10 days. The dosage was 20
drops every 2 hours for the first day and thereafter three times daily 20 drops. Only two patients were
excluded for protocol violation and all completed the study. The time taken to improvement was
significantly shorter (P<0.0001) in the
Echinacea
group than in the placebo group. In the sub-group of
patients with „real“ cold, i.e. fully expressed disease, the median time taken to improvement was 4
days (
Echinacea
group) and 8 days (placebo group). Average termination of treatment due to
improvement was after 6 days (
Echinacea
group) and after 10 days (placebo group). No specific
adverse events were reported. The findings demonstrate that early initiation of treatment with the
expressed juice of
Echinacea purpurea
can reduce the development of the disease and significantly
shorten the duration of the common cold and reduce the length of the treatment period required.
Schulten et al. (2001)
recruited a total of 80 adult male or female patients with first signs of a cold in
a randomised double–blind placebo-controlled trial. The number of days of illness with a complete
picture of the common cold (defined by the modified Jackson score of at least 5 points and experience
of rhinorrhea and/or a subjective sensation of having a cold) was the primary end-point. In the verum
group the median time of illness was 6.0 days compared to 9.0 days in the placebo group, assigning
zero time for patients without a complete picture (one-sided p = 0.0112). EC31J0 was well tolerated
and clinically effective in alleviating symptoms more rapidly than placebo in patients with a common
cold.
Taylor et al. (2003)
studied the efficacy of
Echinacea purpurea
in reducing the duration and/or
severity of URTI symptoms in children. The design of this study was randomised, double-blind,
placebo-controlled trial of healthy children 2 to 11 years old recruited from a regional practice-based
network and an alternative medical center in 4-month periods from 2000 through 2002. Patients were
randomised to receive either
Echinacea
or placebo for up to 3 URIs over a 4-month period. Study
medication was begun at the onset of symptoms and continued throughout the URTI, for a maximum
of 10 days. Data were analysed on 707 URIs that occurred in 407 children, including 337 URIs treated
with
Echinacea
and 370 with placebo. There were 79 children who completed their study period
without having an URTI. The median duration of URIs was 9 days (95% confidence interval, 8-10
days); no difference in duration between URIs treated with
Echinacea
or placebo was found (P =
0.89). No difference in the overall estimate of severity of URTI symptoms between the 2 treatment
groups (median, 33 in both groups; P = 0.69) was found either. There were also no statistically
significant differences between the 2 groups for peak severity of symptoms (P = 0.68), number of days
of peak symptoms (1.60 in the
Echinacea
group and 1.64 in the placebo group; P = 0.97), number of
days of fever (0.81 in the
Echinacea
group vs. 0.64 in the placebo group; P = 0.09), or parental global
assessment of severity of the URTI (P = 0.67). Overall, there was no difference in the rate of adverse
events reported in the 2 treatment groups; however, rash occurred during 7.1% of the URIs treated
with
Echinacea
and 2.7% of those treated with placebo (P = 0.008). The authors of the study
©
EMEA 2008
22/35
concluded that
Echinacea purpurea
, as dosed in this study, was not effective in treating URTI
symptoms in patients 2 to 11 years old, and its use was associated with an increased risk of rash.
There were many critics on this study published in scientific literature (Kim et al. 2004; Firenzuoli &
Gori 2004; Washam 2004; Le Tourneau 2004; Blumenthal 2004) and one answer of the authors
(Taylor et al. 2004). The main critics were that the dosage of
Echinacea
extract in the product was not
stated and the product was not standardized. Additional weakness of the study was that placebo group
used significantly more vitamins and mineral supplements. The patients started to take medication
very late. The parents were asked to call coordinator of the study, when at least 2 symptoms of a URTI
developed, and they started to take medication after the coordinator confirmed that the child met
criteria for having a URTI. Barrett (2004) published a comment supporting the quality of Taylor’s
study.
Weber et al. (2005)
made a follow up of the patients from the study of Taylor et al. (2003). The aim
of this study was to determine whether
Echinacea purpurea
given to children for the treatment of
acute upper respiratory tract infection (URI) was effective in reducing the risk of subsequent URI. A
total of 524 children ages 2 to 11 years were enrolled in the study. Children were monitored for URIs
over a 4-month observation period during the fall/winters of 2000-2001 and 2001-2002. At entry the
children were randomized to receive
Echinacea
or placebo to treat acute URIs during the observation
period. The occurrence of a second URI and the number of days between the end of the first URI and
the start of the second URI was ascertained. Survival and Cox regression analyses were used to
determine whether children who took
Echinacea
for their URIs were less likely to develop subsequent
URIs. Among the 401 children with at least one URI treated with study medication, 69.2% of those
receiving placebo developed a second URI versus 55.8% of those who received
Echinacea
. Use of
Echinacea
was associated with a 28% decreased risk of subsequent URI (p = 0.01, 95% confidence
interval 8%-44% decreased risk).
Echinacea purpurea
may be effective in reducing the occurrence of
subsequent URIs in children.
3.1.2
Non-controlled trial
Götte & Roschke (2001) made observation in children with recurring infections of the upper
respiratory tract to asses the tolerability and efficacy of Echinacin. A good to very good tolerability
and efficacy was found in children above the age of two years and in young adults. 338 paediatricians
treated 1,327 children and young adults with recurring infections of the upper respiratory tract. Only
children who had been affected by at least two infections of the respiratory tract during the past twelve
months were included in the observation of use. The children had to be at least 2 years of age and
show recurring signs and symptoms of a respiratory tract infection. At conclusion of the treatment, the
tolerability was assessed with the aid of the recorded adverse drug reactions and the global assessment
by the physician and the parents of the patients. The symptoms considered were specified on the
observation form (sneezing, running nose, blocked nose, sore throat, cough, headache, feeling of
illness and chill). Furthermore, the physician and parents evaluated the duration of the respiratory tract
infection in historical comparison to the duration of illness without treatment with the juice. A total of
1,322 children and young adults - males and females - were included in the assessment of efficacy. All
patients who had taken the juice at least once were included. A total of 5 patients were excluded from
the analysis of tolerability, because they had not shown up for the final examination and no data
regarding the assessment of tolerability had been recorded for them. The evaluation of efficacy
involved 1,192 children and young adults, 579 females and 609 males. In four cases, the data on sex
were missing. On average, the juice was administered to the patients over a period of 11 days. The
results obtained from this observation of use, with doses adjusted according to age, revealed a good to
very good tolerability and efficacy. In more than 95% of cases, the physician and parents globally
assessed the tolerability as good or very good. More than 60% of the treating physicians and parents
reported that the duration of the respiratory tract infection was shorter in comparison to the duration of
disease without treatment with the juice. The efficacy was rated by the physician as well as by the
parents as very good or good in more than 80% of the cases. In comparison to treatment without the
juice, the physician observed in this respiratory tract infection a shorter duration of disease in more
©
EMEA 2008
23/35
than 60% and the course of disease was rated as less severe in more than 70% of all patients. The
parents of the children and young adults made comparable assessments.
3.1.3
Trials on other indications (prevention) and other preparations (extract) or combinations.
Brinkeborn et al. (1999)
evaluated the efficacy and safety of different doses and preparations of
Echinacea purpurea
in the treatment of common cold in a randomised, double-blind, placebo-
controlled study. 246 of 559 recruited healthy, adult volunteers caught a common cold and took 3
times daily 2 tablets of different
Echinacea purpurea
preparations. Group I got a preparation of 95%
herba and 5% radix, group II got the same preparation as group I but at 7 times higher concentration,
group III got a special
Echinacea purpurea
radix preparation an group IV got placebo tablets.
Duration of treatment was until the patients felt healthy again but not longer than 7 days. Primary
endpoint was the relative reduction of the complaint index defined by 12 symptoms during common
cold according to the doctor's record. The preparations of group I and II were significantly more
effective than the special root extract or placebo. Treatment with 7-fold higher dosage of group II was
only slightly more effective than dosage of group I. The index of 12 symptoms reduced for 63%, 64%
and 45% in group I, II and III, respectively and only for 29% in group IV (placebo). All treatments
were well tolerated. Among the
Echinacea
groups the frequency of adverse events was not
significantly higher than in the placebo group.
Barrett et al. (2002)
assessed the efficacy of dried, encapsulated, whole-plant
Echinacea
as early
treatment for the common cold in a randomised, double-blind, placebo-controlled community-based
trial at University of Wisconsin, on 148 students with common colds of recent onset. Each active
capsule contained a dried mixture of
E. angustifolia
root (50% [123 mg]),
E. purpurea
root (25% [62
mg]), and
E. purpurea
herb (25% [62 mg]).
Echinacea
capsules also contained thyme (49 mg) and
peppermint (31 mg) to disguise taste and flavor, as well as citric acid (3 mg) as a preservative. The
placebo capsules contained 333 mg of alfalfa. The patients took four capsules six times during the first
24 hours of the study, and four capsules three times each day thereafter until symptoms resolved, for a
maximum of 10 days. Severity and duration of self-reported symptoms of upper respiratory tract
infection were recorded. No statistically significant differences were detected between the
Echinacea
and placebo groups for any of the measured outcomes. Trajectories of severity over time were nearly
identical in the two groups. Mean cold duration was 6.01 days in both groups as a whole, 5.75 days in
the placebo group, and 6.27 days in the
Echinacea
group (between-group difference, -0.52 day [95%
CI, -1.09 to 0.22 days]). After controlling for severity and duration of symptoms before study entry,
sex, date of enrolment, and use of nonprotocol medications, researchers found no statistically
significant treatment effect (adjusted hazard ratio, 1.24 [CI, 0.86 to 1.78]). Multivariable regression
models assessing severity scores over time failed to detect statistically significant differences between
the
Echinacea
and placebo groups.
Goel et al. (2004)
studied the efficacy of a well standardized formulation containing alkamides,
cichoric acid, and polysaccharides at concentrations of 0.25, 2.5, and 25 mg/ml, respectively, in
reducing the severity and duration of symptoms of a naturally acquired common cold. The preparation
(Echinilin, Natural Factors Nutritional Products, Inc., Vancouver, BC, Canada) is prepared from
freshly harvested
Echinacea purpurea
plants. In a randomised, double-blind, placebo-controlled trial,
282 subjects aged 18 to 65 years with a history of two or more colds in the previous year, but
otherwise in good health, were recruited. The subjects were randomised to receive either
Echinacea
or
placebo. They were instructed to start the
Echinacea
or placebo at the onset of the first symptom
related to a cold, consuming 10 doses the first day and four doses per day on subsequent days for 7
days. Severity of symptoms (10-point scale: 0, minimum; 9, maximum) and dosing were recorded
daily. A nurse examined the subjects on the mornings of days 3 and 8 of their cold. A total of 128
subjects contracted a common cold (59
Echinacea
, 69 placebo). The total daily symptom scores were
found to be 23.1% lower in the
Echinacea
group than in placebo in those who followed all elements of
the study protocol (P < 0.01). Throughout the treatment period, the response rate to treatments was
greater in the
Echinacea
group. The average of every individual symptom (runny nose, sore throat,
stuffy nose, fatigue, headache, chills) except in cough, was significantly lower in
Echinacea
group
©
EMEA 2008
24/35
compared to placebo. In cough, the difference was not significant. No differences in white blood cell
differential count were observed between the treatment groups.
In their next study
Goel et al. (2005)
administered EchinilinTM or placebo to volunteers at the onset
of their cold for a period of 7 days, with eight doses (5 mL/dose) on day 1 and three doses on
subsequent days. Fasting blood samples were obtained before and during their colds. The decrease in
total daily symptomatic score was more evident in the echinacea group than in the placebo group.
These effects of echinacea were associated with a significant and sustained increase in the number of
circulating total white blood cells, monocytes, neutrophils and NK cells. In the later part of the cold,
the echinacea treatment suppressed the cold-related increase in superoxide production by the
neutrophils. These results suggest that EchinilinTM, by enhancing the non-specific immune response
and eliciting free radical scavenging properties, may have led to a faster resolution of the cold
symptoms.
Baetgen (1984)
compared the therapy i.m. injection of 1-2 ml of diluted
Echinacea purpurea
expressed juice alone or in combination with antibiotics on three successive days for the treatment of
pertussis, in a retrospective study of 170 children. In about one third of cases (35%) the duration of
pertussis could be reduced to five days by giving i.m. injections of
Echinacea
expressed juice. In 81%
of cases the reduction of duration was to 10 days.
A combination of
Echinacea
and antibiotic is not equally effective. Out of this group of 77 patients
only 9% improved within 5 days and 53% within 10 days of treatment. But the combination is superior
to treatment with an antibiotic alone. Only 10% of the patients treated with antibiotics alone improved
within 5 days and 46% within 10 days. Injections of
Echinacea
have been tolerated well; temperature
rises up to 39°C on the day of treatment were only seen in isolated cases. Erythema and localized pain
at the injection site were occasionally reported.
Baetgen (1988)
obtained similar results in a comparative evaluation of 1280 children suffering from
bronchitis. In this retrospective evaluation it was demonstrated that 3 or 4 i.m. injections of
Echinacea
purpurea
expressed juice can significantly shorten the duration of the infection in comparison with a
group treated with antibiotics alone or with antibiotics plus
Echinacea purpurea
expressed juice. In
Echinacea
group 45.7% of patients improved in 5 days, in
Echinacea
+ antibiotics and in antibiotics
group the improvement was 25.5% and 16% respectively.
Grimm & Müller (1999)
randomly assigned 108 patients with a history of more than 3 colds or
respiratory infections in the preceding year to receive 4 ml
Echinacea purpurea
expressed juice (54
patients) or 4 ml placebo juice (54 patients) twice a day in a double-blind, randomised, prospective
study. The incidence and severity of colds and respiratory infections were determined during 8 weeks
of follow-up, based on patient reported symptoms together with findings on physical examination. The
severity of each infection was graded by the investigators. During the 8-week treatment period 35
(65%) of 54 patients in the
Echinacea
group and 40 (74%) of 54 patients in the placebo group had at
least one cold or respiratory infection. The average number of colds and respiratory infections per
patient was 0.78 in the
Echinacea
group, and 0.93 in the placebo group. Median duration of colds and
respiratory infections was 4.5 days in the
Echinacea
group and 6.5 days in the placebo group.
Although the incidence, duration and severity of colds and respiratory infections tended to be lower in
the
Echinacea
group, none of the results reached statistical significance. Side effects were observed in
11 patients (20%) of the
Echinacea
group and in seven patients (13%) of the placebo group. The
majority of adverse events was mild and transient and did not require discontinuation of the allocated
treatment. In the
Echinacea
group there were 4 drop-outs because of nausea, constipation, awful taste
of the study medication and patient’s choice without any specific reaction.
Turner et al. (2000)
assessed the effectiveness of
Echinacea
for the prevention of experimental
rhinovirus colds in a randomised double–blind placebo-controlled trial. The preparation is not well
described in the publication. It contained 0.16% cichoric acid with almost no echinacosides or
alkamides. Infection occurred in 44 and 57% and illness occurred in 36 and 43% of the
Echinacea
-
©
EMEA 2008
25/35
and placebo-treated subjects, respectively. The effect on either the occurrence of infection or the
severity of illness was not significant.
Sperber et al. (2004)
studied the ability of
Echinacea purpurea
to prevent experimental infection with
rhinovirus type 39 (RV-39) in a randomised double–blind placebo-controlled trial. Forty-eight
previously healthy adults received pressed juice of the above-ground plant parts of
E. purpurea
placed
in a 22% alcohol base (EchinaGuard) or placebo, 2.5 ml 3 times per day, for 7 days before and 7 days
after intranasal inoculation with RV-39. Nine symptoms were assessed three times daily for 14 days to
evaluate clinical illness. Viral culture and serologic studies were performed to evaluate the presence of
rhinovirus infection. A total of 92% of
Echinacea
recipients and 95% of placebo recipients were
infected. Colds developed in 58% of
Echinacea
recipients and 82% of placebo recipients (p = 0.114 by
Fisher’s exact test). Seven-day total symptom score was 30.3% higher in placebo group (p 0.317).
The most significant difference was in sore throat, which was 135.6% higher in placebo group
compared to
Echinacea
(p = 0.065). The differences between the
Echinacea
and placebo were not
significant; however, because of the small sample size, statistical hypothesis testing had relatively
poor power to detect differences in the frequency and severity of illness.
3.1.4
Reviews
An overview and quantitative meta-analysis of the published
Echinacea
trials was performed by
Melchart et al. (1994), Dorsch (1996), Barrett et al. (1999), Giles et al. (2000), Bauer (2002), Barrett
(2003), Barnes et al. (2005) and Linde et al. (2006). Most of the authors reviewed not only studies
with
Echinacea purpurea
expressed juice but also extracts of
E. angustifolia
,
E. pallida
and in
combination with other plant extracts or homeopathic dilutions.
In Melcharts review (Melchart et al. 1994), 26 controlled clinical trials were identified, but the
methodological quality of most studies was rated low. Nonetheless the authors concluded that
Echinacea
preparations could be efficacious immunomodulators.
Barrett et al. (1999) reviewed 9 treatment trials and 4 prevention trials of sufficient quality. 8 of the
treatment trials reported positive results and 3 of the prevention trials reported marginal benefit.
Giles reviewed 41 references and concluded that
Echinacea
appears to be well tolerated with a low
frequency of adverse effect, such as mild dyspepsia, headache and dizziness (Giles et al. 2000).
Evaluated studies support
Echinacea
in the treatment of URTI, but not to prevent infection.
Bauer reviewed new clinical studies (Bauer 2002). He summarised that corresponding preparations
can diminish the severity and the length of common colds significantly, and that they can also be used
efficiently for the treatment of children. Stimulation of macrophages and induction of cytokines are
major parts of the mode of action and the glycoproteins/polysaccharides and alkamides are part of the
activity relevant constituents.
Barrett (2003) concluded in his second review that the treatment of acute upper respiratory infections
with
Echinacea purpurea
, is tentatively supported by the available literature. Reduction of symptoms
with early treatment has been reported in several moderate quality randomised controlled trials.
Benefits appear to be a modest, with a 10 to 40% reduction of symptoms as the most widely reported
outcome. Benefit as a cold preventative appears marginal, at best, with an estimated 5 to 15% effect
size.
The authors of Cochrane Review concluded (Linde et al. 2006):
Echinacea
preparations tested in
clinical trials differ greatly. There is some evidence that preparations based on the aerial parts of
Echinacea purpurea
might be effective for the early treatment of colds in adults but results are not
fully consistent. Beneficial effects of other
Echinacea
preparations, and for preventative purposes
might exist but have not been shown in independently replicated, rigorous randomised trials.
Since the literature search for the first version of this Assessment report was finished in January 2006,
no new clinical trials on
Echinacea purpurea
were published, but 14 new review articles can be found
in Pubmed. Some of recent review articles conclude, that the efficacy of
Echinacea purpurea
is not
well supported, since the quality of the clinical trials was not adequate, or the results are not fully
©
EMEA 2008
26/35
consistent. All of the reviews with negative conclusions, that were available to the raporter have major
inconsistencies and drawbacks:
Koenig & Roehr (2006) in their one-page review article (plus one page with a Table) state, that: “trials
with a larger number of individuals failed to show a significant effect of
Echinacea
treatment, whereas
smaller trials did document positive effects.” This is in fact not true, it can be seen from the Table 2 of
their review (there is no Table 1 in the article), that significant effect was shown by the 1
st
, 3
rd
, 6
th
and
7th largest trials.
In many reviews, different
Echinacea
species and different herbal preparations are not considered
separately. As some species and some preparations might not have the same efficacy as the expressed
juice of the
Echinacea purpurea
herb, the pooled analysis led to the false conclusion, that the results
are inconsistent.
The most thorough review and meta-analysis was made recently by Shah et al. (2007) evaluating the
effect of
Echinacea
on the incidence and duration of the common cold. 14 unique studies were
included in the meta-analysis. Incidence of the common cold was reported as an odds ratio (OR) with
95% CI, and duration of the common cold was reported as the weighted mean difference (WMD) with
95% CI. Weighted averages and mean differences were calculated by a random-effects model
(DerSimonian-Laird methodology). Heterogeneity was assessed by the Q statistic and review of
L'Abbé plots, and publication bias was assessed through the Egger weighted regression statistic and
visual inspection of funnel plots.
Echinacea
decreased the odds of developing the common cold by
58% (OR 0.42; 95% CI 0.25-0.71; Q statistic p<0.001) and the duration of a cold by 1.4 days (WMD -
1.44, -2.24 to -0.64; p = 0.01). Similarly, significant reductions were maintained in subgroup analyses
limited to Echinaguard/Echinacin use, concomitant supplement use, method of cold exposure, Jadad
scores less than 3, or use of a fixed-effects model. The authors concluded that published evidence
supports
Echinacea
's benefit in decreasing the incidence and duration of the common cold (Shah et al.
2007).
3.2
Use in special populations
3.2.1
Use during pregnancy and lactation
Pregnancy outcome in women that used
Echinacea
during pregnancy was studied to evaluate the
safety of
Echinacea
(Gallo et al. 2000). Since at least half of all pregnancies are unplanned, many
women inadvertently use
Echinacea
in their first trimester. The study group consisted of 206 women
who were prospectively followed up after contacting the Motherisk Program regarding the gestational
use of
Echinacea
, 112 women used the herb in the first trimester. This cohort was disease-matched to
women exposed to nonteratogenic agents by maternal age, alcohol, and cigarette use. Rates of major
and minor malformations between the groups were compared. There were a total of 195 live births,
including 3 sets of twins, 13 spontaneous abortions, and 1 therapeutic abortion in
Echinacea
group.
Six major malformations were reported, including 1 chromosomal abnormality, and 4 of these
malformations occurred with
Echinacea
exposure in the first trimester. In the control group, there
were 206 women with 198 live births, 7 spontaneous abortions, and 1 therapeutic abortion. Seven
major malformations were reported. There were no statistical differences between the study and
control groups for any of the end points analysed. The authors concluded that gestational use of
Echinacea
during organogenesis is not associated with an increased risk for major malformations.
In a survey among 400 Norwegian women (Nordeng & Havnen, 2004) 36% used herbal drugs during
pregnancy with an average of 1.7 products per woman.
Echinacea
was used by 23% of pregnant
woman and was by far the mostly used herb.
A review on safety of
Echinacea
during pregnancy and lactation was published recently (Perri et al.
2006). They searched 7 electronic databases and compiled data according to the grade of evidence
found. They found a good scientific evidence from a prospective cohort study that oral consumption of
Echinacea
during the first trimester does not increase the risk for major malformations. Low-level
evidence based on expert opinion shows that oral consumption of
Echinacea
in recommended doses is
©
EMEA 2008
27/35
safe for use during pregnancy and lactation. They concluded that
Echinacea
is non-teratogenic when
used during pregnancy. Caution with using
Echinacea
during lactation until further high quality
human studies can determine its safety.
A study on mice showed that the pregnancy-induced elevation in splenic lymphocytes was reduced by
the diet containing
Echinacea purpurea
extract. Such diet also reduced the number of foetuses,
although the diet started only after the pregnancy was established. None of the observed changes
except for the pregnancy-induced elevation in immune function was significant (Chow et al. 2006).
3.2.2
Use in children
Of the 14 above reviewed clinical trials 4 were performed in children. The youngest children were
included in the two studies by Baetgen (Baetgen 1984, Beatgen 1988) where the minimal age was 1
month. The average age was 3.5 years in one study and 2.8 years and 3.1 years for boys and girls,
respectively in the other study.
A recent study (Taylor et al. 2003) included 2 years to 11 years old children (mean 5.5 years, standard
deviation 2.7 years). In this study adverse events were found in 45.1% of patients receiving
Echinacea
(and in 39.5% of patients receiving placebo). The most frequent adverse events were: stomachache,
diarrhea, drowsiness, headache, ”hyper” behaviour, rush and vomiting. Rash was the only side effect
that was significantly more frequent in
Echinacea
group compared to placebo.
Information on 4 (unpublished) observational studies regarding the safety of the oral application of
Echinacea purpurea
herba preparations in different dosages for children below the age of 18 was
submited by German authority:
415 children with a median age of 15, thereof 198 children below the age of 12, median age 8
suffering from acute respiratory tract infection received tablets containing 100mg dried expressed
juice of flowering herb of
Echinacea purpurea
(DER 22-65:1) for 2 weeks. Due to the pharmaceutical
form tablets we accepted the following posology for children from 6-12 : 2-3 x l tablet and for children
from 12-18 the adult posology. 1 exanthema was observed, 1 x nausea and vomiting otherwise there
were no reports concerning adverse events. (scientific investigator: Dr. Hellemann).
359 children thereof 357 in between 1-12 years (290 < 10years; 67 > 11 years) suffering from acute
respiratory tract infection received a liquid (100 ml containing 3.75 g dried expressed juice from fresh
flowering herb of
Echinacea purpurea
(DER 22-65:1) for 2 weeks. 3 ml of the liquid correspond to
2,1 ml of fresh juice. Children from 6-11 received 3-4 x 2 ml liquid daily (corresponding to 4.2-5.6 ml
fresh juice). Reported adverse events were bad taste 1 x and one generalized exanthema, which could
be due to the infect as well. (scientific investigator: Dr. Heidi)
140 children (0-1 y n = 26; 1-4y n = 38; 4-12y n = 76) suffering from acute respiratory tract infection
received daily doses as followed : 0-1 y 1-2 x 2,5 ml; 1-4y 1-2 x 5 ml; 4-10y 2-3 x 5 ml and 10-12y 1
x 15-2 x l0 ml of expressed juice of flowering herb of
Echinacea purpurea
(DER: 1:0.65–0.85) for 2
weeks. 2 children dropped out due to the bad taste of the preparation adverse events were not reported.
270 children (1-4y n = 140; 4-12y n = 130) suffering from acute respiratory tract infection received a
liquid (100g liquid contain 1.0769 dried expressed juice from fresh flowering
Echinacea purpurea
(DER: 22-65:1). 10 ml liquid correspond to 2.5 ml expressed juice). The posology was the following:
14y: 2-3x5 ml liquid (average 14.4 ml liquid corresponding to 3.6 ml expressed juice); 4-12y: 2-3x
l0 ml average 27.4 ml liquid corresponding to 6.85 ml expressed juice. The duration of treatment was
10 days. 8 children dropped out due to recovery 10drop outs were due to antibiotic treatment which
was defined as elimination criterion, 1 time bad taste. Adverse events reported 1 x nausea, 1 x bad
taste.
©
EMEA 2008
28/35
3.2.3
Use in the elderly
In most clinical studies, the patients up to 65 years old were included (Hoheisel et al. 1997;
Brinkeborn et al. 1999; Grimm & Müller 1999; Schulten et al. 2001; Turner et al. 2000; Barrett et al.
2002; Goel et al. 2004; Sperber et al. 2004; Yale & Liu 2004).
No restrictions are known on the use of preparations from
E. purpurea
.
3.2.5
Effects on ability to drive and use machines
None known (ESCOP 2003).
3.3
Dosage
3.3.1
Treatment of common cold
There are no dose-finding studies available.
In a study of
Brinkeborn et al. (1999)
the treatment with 7-fold higher dosage was only slightly more
effective than treatment with 36 mg of dry extract.
Table 1 summarizes the doses and formulation of
Echinacea purpurea
products used in clinical trials.
The doses and formulation recommended by monographs and reviews are:
WHO 1999
powdered aerial part, pressed juice and
galenic preparations thereof
6-9 ml per day
ESCOP 2003
Expressed juice or other equivalent
preparations
6-9 ml per day for adults.
Proportional dose for children.
Kommission E
Expressed juice
6-9 ml per day
Dorsch et al. 2002 Expressed juice
3 ml per day (1-4 year)
3–5 ml per day (4-10 year)
6–9 ml per day (10-16 years)
3.3.2
Topical use
The posology for topical use (Traditional herbal medicinal product for treatment of small superficial
wounds) is not available in the literature. 10 to 20 g of expressed juice per 100 g of preparation is used
in most products on European market (see pages 4 to 8)
3.3.3
Duration of use
Most of the monographs (WHO, ESCOP, Kommision E) state the following general precaution: “Not
to be used for more than 8 weeks”.
Since only curative but not prophylactic efficacy of
Echinacea purpurea
is demonstrated in clinical
trials, this period can be shortened to 2 weeks to minimise the side effects. We therefore recommend
the general precaution: “Not to be used for more than 10 days”.
3.4
Traditional use
Medicinal uses of
Echinacea
species among American Indians, were many and varied.
E. angustifolia
was universally used as an antidote for snakebite and other venomous bites and stings and poisonous
conditions.
Echinacea
have been used as a remedy for more ailments than any other plant (Foster
1996).
Echinacea purpurea
was first mentioned in 1787. It was used for treating ulcers on a horses's
back caused by saddles. Subsequently, the plant was largely neglected until the first edition of the
Eclectic Dispensatory
in 1852
.
The European history of the introduction and use of
Echinacea
©
EMEA 2008
29/35
purpurea
in many ways parallels its history in the U.S. By 1895
Echinacea
products for homeopathic
physicians had become available in Germany. Over the next 30 years the demand increased, while
shortages were prevalent in Europe. Subsequently, in the late 1930s, commercial cultivation of
E.
purpurea
began in Germany, introducing
Echinacea
products to a wide European audience for the first
time. The majority of pharmacological and clinical studies conducted since 1939 have involved
E.
purpurea
preparations made from the fresh expressed juice of the flowering plant (primarily
Echinacin, Madaus AG, Cologne, Germany). Product forms include an ointment, a liquid form for
external use, and an extract for internal use, as well as ampoules for intravenous and intramuscular
injection.
Information about the use of the plant from traditional healers ranges from external application for
wounds, burns and insect bites to the chewing of roots for toothache and throat infections, and internal
application for pain, coughs, stomach cramps and snake bites. The interest of white settlers was also
drawn to this medicinal plant. The first
Echinacea
preparation, known as Meyers Blood Purifier,
arrived on the market around 1880, with rheumatism, neuralgia and rattlesnake bites as indications
(Hostettman 2003).
An overview of use in EU member states is presented in the Table on page 4.
4
Safety
4.1
Toxicity
4.1.1
Single-Dose Toxicity
Echinacea purpurea
and in particular the expressed juice is toxicologically well examined. Acute
intoxications are not reported and on the basis of the animal experimental data are not expected.
After single p.o. or i.v. application of
Echinacea purpurea
expressed juice in dose of p.o. 15,000
mg/kg or i.v. 5,000 mg/kg on rats and p. o. 30,000 mg/kg or i.v. 10,000 mg/kg on mice the animals
showed no abnormalities. Since no deaths were observed, the LD50 could only be determined by
approximation method. The sections at the end of the experiments did not result in referring to organ
changes (Mengs et al. 1991).
A mixture of polysaccharides from the herb of
Echinacea purpurea
and two polysaccharides, obtained
from a cell culture medium of
Echinacea
, resulted after i.p. application on mice in LD50-values of
>2,500mg/kg and/or >5,000mg/kg. For the two pure polysaccharides (Fucogalactoxyloglucan, acid
arabino galactan) no toxicity was stated (Lenk 1989).
4.1.2
Repeat-Dose Toxicity
After 4 weeks of oral administration of
Echinacea purpurea
expressed juice in doses of 800, 2,400 or
8,000 mg/kg daily, the male rats (2,400 and 8,000 mg/kg) showed a statistically significant fall in
plasma alkaline phosphatase, while the females (2,400 and 8,000 mg/kg) showed a rise in prothrombin
time. Since all the values were still within the range of physiological variation for the used strain of
rats, and since there was no dose proportionality, no toxicological significance can be ascribed to these
findings. All the other laboratory results, together with the body weights, food consumption,
ophthalmoscopy, necropsy findings and histology failed to show any evidence of relevant differences
between the groups (Mengs et al. 1991).
4.1.3
Genotoxicity
Echinacea purpurea
expressed juice (Echinacin and lyophilised expressed juice) in concentrations
from 8 to 5,000 microg/plate were examined. The performance of the tests and the used concentrations
were according the „Note for guidance on genotoxicity: Guidance on specific aspects of regulatory
genotoxicity tests for pharmaceuticals“ (CPMP/ICH/141/95). In the examined bacterial test systems on
©
EMEA 2008
30/35
Salmonella typhimurium (TA98, TA100, TA1535, TA1537, TA1538) with and without metabolic
activation by the S9-fraction from liver of Arochlor-1254-treated rats no evidence of toxicity was
observed. In the mouse lymphoma assay with and without S9-fractions, in the human lymphocyte
assay, and in the micronucleus assay no referring to genotoxic effects or to cell transformation effects
(Mengs et al. 1991) resulted.
For the neutral polysaccharide NFA 10 from
Echinacea purpurea
tissue culture in human lymphocyte
cultur neither in the short time nor in the long-term experiment in concentrations up to 500 microg/ml
significant dose-dependent sister chromatid exchance (SCE) inducing activity nor a clastogenic
potency was observed (Schimmer et al. 1989).
The fresh plant extract of
Echinacea purpurea
does not show mutagenic effects in the
Salmonella
microsome assay TA98 and TA100. Referring to the mentioned investigations the risk of unwanted
mutagenic effects is extremely small in
Echinacea purpurea
preparations.
4.1.4
Carcinogenicity
So far no investigations are present, which permit the evaluation of a cancer risk. In a cell
transformation test
Echinacea purpurea
did not produce any morphological transformation of
embryonic hamster cells (Mengs et al. 1991). In-vitro model systems of this kind are gaining
increasing credibility for the testing of carcinogenic potential, since there is good correlation between
the results of such tests and of chronic whole-animal carcinogenicity studies. Because of the negative
results of the experimental investigations for genotoxicity it is not necessary to carry out long-term
carcinogenicity studies in mammals.
4.1.5
Reproductive and Developmental Toxicity
No preclinical data on reproductive and developmental toxicity of
Echinacea purpurea
is available.
There is some data on reproductive and developmental toxicity from clinical studies and this data is
described in Clinical overview.
Echinacea purpurea
did not have an effect on sperm motility parameters (Ondrizek et al. 1999).
Washed sperms were incubated in either saw-palmetto,
Echinacea purpurea
,
Ginkgo biloba
,
Hypericum perforatum
or control medium. Parameters were measured on a Hamilton-Thorn analyzer
after 1, 4, 24, and 48 hr at 37°C. Sperm motility was inhibited at the 0.6 mg/ml concentration of St.
John's wort. Curvilinear velocities and beat cross frequencies also decreased, but not hyperactivation.
High-concentration (8 mg/ml) saw-palmetto,
Echinacea
, or
Ginkgo
inhibited motility at 24 and 48 hr.
A potent inhibition of sperm motility was seen in St. John's wort unrelated to changes in pH.
Furthermore, sperm viability was compromised in St. John's wort, suggesting a spermicidal effect.
Metabolic changes were observed in saw-palmetto-treated sperm. High-concentration
Echinacea
purpurea
interfered with sperm enzymes.
Ginkgo
did not have an antioxidant effect on sperm motility.
4.1.6
Local Tolerance
Data on local tolerance of
Echinacea purpurea
are not available.
4.1.7
Immunotoxicity
Echinacea belons to “Pharmacotherapeutic group: ATC-code: L03AW05 immunomodulators of plant
origin.
Echinacea purpurea
stimulates nonspecific immune system (phagocytosis by macrophages,
natural killer cells activity).
In the “Note for Guidance on immunotoxicity studies for human pharmaceuticals”
(EMEA/CHMP/167235/2004) the following statement is given: “Immunotoxicity is, for the purpose of
this guideline, defined as
unintended
immunosuppression or enhancement”. Immunotoxicity study of
Echinacea
is therefore not needed.
©
EMEA 2008
31/35
4.2
Contraindications
Hypersensitivity to plants of the Asteraceae family. As with all immunostimulants,
Echinacea
is not
recommended in cases of progressive systemic disorders and autoimmune diseases
immunodeficiencies, immunosuppression and diseases of the white blood cell system such as
tuberculosis, leukoses, collagenoses, multiple sclerosis, AIDS or HIV-infections
This is a theoretical possibility as until recently; no immunostimulatory herbal supplements have been
reported to exacerbate disorders of immune system overactivity (Lee & Werth 2004). Lee reports a
case of one 55-year-old patient who was diagnosed as having pemphigus vulgaris in 1995. His medical
history was notable for chronic uveitis, which required long-term treatment with systemic steroids, and
osteoporosis secondary to long-term systemic steroid use. At diagnosis, the patient had not taken
systemic corticosteroids for 4 months. His disease was gradually controlled with prednisone, dapsone,
and azathioprine. The patient achieved complete clearance of lesions in October 1997 and continued to
be clear of lesions after prednisone and azathioprine therapy was discontinued in May 1998, after
which he received low doses of dapsone. In October 1998, he developed an upper respiratory tract
infection and began taking an
Echinacea
supplement daily. He had never before taken an herbal
supplement. He developed blisters on his trunk, head, and oral mucosa within one week of starting the
supplement. He had not had oral mucosa lesions since onset of the disease. After discontinuing the use
of the
Echinacea
supplement, partial disease control, but never complete remission, was achieved with
prednisone, azathioprine (later changed to mycophenolate mofetil), and dapsone.
Children under 1 year of age should not use
Echinacea
, because their immune system is not fully
developed.
4.3
Special warnings/precautions for use
In atopic patients severe immune reactions can occur immediately after the first exposure to
Echinacea
. Five cases were reported in Australia (Mullins & Heddle, 2002).
Regular ingestion of
Echinacea
by up to 5% of surveyed patients with atopy, combined with detection
of
Echinacea
-binding IgE in atopic subjects (19% by skin testing; 20% with moderate to strong
reactivity by RAST testing), raises the possibility of severe allergic reactions, even with first-time use,
due to cross-reactivity with other structurally similar allergens (Mullins 1998).
The association of
Echinacea
with allergic reactions is supported by the evaluation of Huntley et al.
(2005). While these reactions are reported to be rare, patients with allergy or asthma are advised to
carefully consider their use of
Echinacea
.
The use in children between 1 and 12 years of age is not recommended because efficacy has not been
sufficiently documented although specific risk in children over 1 year of age are not documented.
©
EMEA 2008
32/35
4.4
Undesirable effects
On the basis of the results of the investigations reviewed above, tolerance was well-indicated without
exception in the case of oral administration. In parenteral applications, localized symptoms and fevers
occasionally occurred.
In a multicentre uncontrolled study, a total of 1,231 patients with relapsing respiratory and urinary
infections were treated for 4 to 6 weeks with
Echinacea purpurea
expressed juice. In 5% of patients
adverse events were reported (Parnham 1996). The most frequently cited was an unpleasant taste of
the study medication in 1.7% of patients, followed by nausea/vomiting (0.5%), recurrent infection
(0.4%), sore throat (0.2%), abdominal pain (0.2%), diarrhoea (0.2%), difficulty in swallowing (0.2%),
and other single reports (1.5%).
Kemp & Franco (2002)
published a case report of leucopoenia associated with long-term use of
Echinacea
. A 51-year-old woman appeared healthy form all aspects with the exception that her white
cell count had decreased from 5,800/ microlitre the preceding year to 3,300/ microlitre (normal range
4,000 to 11,000). For the past 8 weeks she had been taking 1,350 mg of
Echinacea
per day. One
month after discontinuation of therapy with
Echinacea
, her white cell count had increased to 3,700/
microlitre. Next year she resumed taking
Echinacea
and after two months her white cell count was
2,880/ microlitre. Two months after discontinuing
Echinacea
, her white cell count was 3,440/
microlitre and 7 months later rose to 4,320/ microlitre.
The connection between the
Echinacea purpurea
therapy and the undesirable effect can be estimated
as: certain.
Soon & Crawford (2001)
reported on a case of a 41 old man with 4 recurrent episodes of erythema
nodosum preceded with prodromi like myalgias, arthalgias, fever, headache and malaise, which
resolved under prednisolone therapy. Comedication was loratadine as needed, St. John's wort for 6
month; and intermittent
Echinacea
for 18 month. Other reasons were excluded. After dechallenge he
was free of erythema nodosum despite persistence of intermittent flulike symptoms for over a year. A
rechallenge with
Echinacea
was refused by the patient. The connection between the
Echinacea
purpurea
therapy and the undesirable effect can be estimated as: probable.
Logan & Ahmed (2003)
reported on a 36 year old woman had taken St.John's wort,
Echinacea
and
kava for 2 weeks when she developed a severe general muscle weakness, which resolved under
supplementation of NaHCO
3
and KCl. Complaints of joint stiffness, fatigue, dry mouth and eyes
surfaced 6 weeks later.The serum was negative for double stranded anti DNA, Smith and RNP
antibodies. Sjogren Syndrome was diagnosed and Plaquenil treatment begun. The abnormalities renal
tubular function resulting in hypokalimea and acidification with muscle weakness are reported because
of a Sjogren Syndrome. Problems resolved under therapy with prednisone and cyclophosphamide,
which underlines the autoimmunogenesis The connection between the
Echinacea purpurea
therapy
and the undesirable effect can be estimated as: possible.
In a clinical study on children (Taylor et al. 2003) there was no difference in the overall rate of adverse
events reported in the 2 treatment groups (
Echinacea
and placebo); however, rash occurred during
7.1% of the URIs treated with
Echinacea
and 2.7% of those treated with placebo (P = 0.008).
Data from clinical studies and spontaneous reporting programmes suggest that adverse events with
Echinacea
are not commonly reported (Huntley et al. 2005). Gastrointestinal upsets and rashes occur
most frequently. However, in rare cases,
Echinacea
can be associated with allergic reactions that may
be severe.
Pharmacovigilance reports from member states:
©
EMEA 2008
33/35
Ireland
8 case reports including 20 adverse reactions as follows: 1 Joint pain, 3 Abdominal pain, 1
Oedema, 1 Goitre, 1 Pharyngitis, 1 Amenhorrhoea, 1 Abnormal White Blood Cell Count, 1
Fatigue, 1 Hives, 1 Purpura, 1 Dizziness, 2 Headache, 1 Feeling of Drunkenness, 1
Hypoglycaemia, 1 Chest pain, 1 Attention Deficit Hyperactivity Disorder, 1 Bone disorder
On case of positive pregnancy test in a patient taking an OCP and
Echinacea
concomitantly.
Germany 127 case reports of adverse events in patients taking
Echinacea
(in most cases in
combination with other drugs) were documented in Germany from 1984 to 2006. Many
adverse events happened in intravenous application of
Echinacea
extract for treating
hypersensitivity, allergic rhinitis, ...
In patients with no concomitant therapy besides the oral therapy with
Echinacea
the
following adverse events were observed in the period 1991-1996:
6 x : diarhea, nausea
4 x : pain abdominal, rush
3 x: taste disturbance
2 x: itching, rigors, trombocytopenia, urticaria acute, vomiting
1 x: aggraviation of existing disorder, allergic reaction, allergy aggravated, asthmatic
attack, cough, cramp abdominal, diarrhoea bloody, dry mouth, dyspepsia, dysphagia, ear
ache, erythema, exanthema, face oedema, facial flushing, facial pain, facial swelling,
fainting, fever, haematuria, headache, hepatitis A, hives, hypersensitivity, leucopenia, lip
oedema, malaise, numbness localized, numbness oral, pemphigus, petechiae, pharingitis,
pruritis, pustular rash, Quinckes oedema, sweating attack, swelling non-inflamatory,
swelling of knees, swollen eyelids, temperature elevation, therapeutic response decreased,
urticaria, vertigo
Some of undesirable events found in pharmacovigilance data and in the uncontrolled study (Parnham
1996) can not be considered as “undesirable effects”, since they are the symptoms of the disease
which is treated by this medicinal product. The importance of evens connected to GIT can not be
estimated without the control group. Many of those undesirable events occurred also in controlled
trials, but their frequency was not different to placebo.
4.5
Interactions
See 2.3
4.6
No case of overdose has been reported.
5
Overall Conclusion
Preparations of
Echinacea purpurea
are used for many decades in humans.
Pharmacological and toxicological characteristics are specified in this report. All investigations of the
acute and subacute toxicity of
Echinacea purpurea
dry expressed juice, even in the case of excessive
dosages, did not result in referring to toxic effects. Also the extensive tests for a possible mutagenic
potential were negative. Furthermore no malignant transformation of mammalian cells could be
induced by
Echinacea purpurea
dry expressed juice in an in-vitro test.
In view of the results of the preclinical toxicological studies, clinical trials and of several decades of
experience of its use in human beings, the expressed juice of
Echinacea purpurea
can be classified as
a safe and well tolerated drug. Some adverse effects connected to the immunostimulatory action of
Echinacea
were observed in clinical trials and in clinical practice (rush, urticaria).
©
EMEA 2008
34/35
The pharmacological effects of
Echinacea purpurea
preparations on immune system were proven
beyond any doubt. On the other hand the mechanism of action and the active compound are not totally
clear yet.
There are many clinical studies published. Despite the fact, that they are not of optimal quality and
they did not all prove the efficacy of the drug, herbal drug preparations made of
Echinacea purpurea
can be considered effective in the treatment of respiratory tract infections.
Echinacea purpurea
has well established use
for the short-term prevention and treatment of common
cold. The common cold was in most clinical trials diagnosed by the patients on the basis of first
symptoms.
Traditional use of
Echinacea purpurea
in this indication is not possible
, due to side effects and
interactions, which, although they are very limited, can not be overweighed by the “plausible”
therapeutic activity.
Traditional use for topical treatment of small superficial wounds
is well documented in the
overview of European market.
©
EMEA 2008
35/35
Source: European Medicines Agency
- Please bookmark this page (add it to your favorites).
- If you wish to link to this page, you can do so by referring to the URL address below this line.
https://theodora.com/drugs/eu/echinaceae_purpureae_herba_herbal.html
Copyright © 1995-2021 ITA all rights reserved.