HERBAL
MEDICINAL
PLANT
NETTLE
Urtica dioica L. (Urticaceae) +++
BY
RETTODWIKART THENU
NETTLE
(neh’tuhl)
Urtica
dioica L. (Urticaceae) +++
SUMMARY AND PHARMACEUTICAL COMMENT
The
chemistry of nettle is well documented. Limited pharmacological data are available
to support the traditional herbal uses although hypoglycaemic activity in vivo has been reported. There
is very limited evidence from clinical trials to support the diuretic and anti-inflammatory
effects of nettle, and for the effects of nettle in relief of symptoms of
allergic rhinitis. Clinical evidence exists to support the efficacy of root extracts
in the treatment of benign prostatic hyperplasia.
However,
further well-designed clinical trials of nettle involving large numbers of patients
are required to establish the benefits. Irritant properties have been
documented for nettle, and excessive use and use during pregnancy and lactation
should be avoided.
TRADE NAMES
Alcohol
Free Nettles Leaf, Basics Stinging Nettle, Certified
Organic
Netties Leaf, Nettle Leaf, Nettle Herb, Nettle Power
OTHER COMMON NAMES
Nettle
DESCRIPTION
MEDICINAL
PARTS:
The
medicinal parts are the fresh and dried flowering plant and the roots.
FLOWER
AND FRUIT:
The
flowers are greenish-white in axillary, clustered, hanging panicles. The
perigone has 4 tepals. There are 4 stamens and 1 ovary with a brush-like
stigma. The flowers are dioecious. The male flowers have only stamens and the
female flowers only a style or a seed-producing organ. The male flower consists
of a perianth of 4 segments, which enclose an even number of stamens. The
stamens curve inward in the bud stage and spring back at the end of flowering
for the anthers to fling out the pollen. The fruit is a small 1-seeded nutlet.
LEAVES,
STEM AND ROOT:
The
plant grows from 60 to 150 cm high and has a winter hard rhizome. The leaves
are opposite, oblong-cordate and roughly serrate. The whole plant is covered in
stinging hairs.
HABITAT: The plant is
common in most temperate regions of the world.
PRODUCTION: Stinging Nettle
herb consists of the fresh or dried above-ground parts of Urtica dioica, Urtica
urens and/ or hybrids of these species, collected during flowering season.
Stinging nettle leaf consists of fresh or dried leaves of Urtica dioica, Urtica
urens and/or hybrids of these species, gathered during flowering season.
NOT
TO BE CONFUSED WITH: The leaves of Laminum album.
SPECIES (FAMILY)
Urtica dioica L. (Urticaceae) +++
SYNONYM(S)
Stinging Nettle, Urtica
ORIGIN
Nettle is a perennial found in
Europe, the United States, and Canada.
PHARMACOPODIAL AND OTHER MONOGRAPHS
BHC 1992(G6)
BHP 1996(G9)
BP 2007(G84)
Complete German Commission E(G3)
ESCOP 2003(G76)
Martindale 35th edition(G85)
Ph Eur 2007(G81)
USP29/NF24(G86)
LEGAL CATEGORY (LICENSED PRODUCTS)
GSL(G37)
CONSTITUENTS
The
following is compiled from several sources, including General References G6 and
G52.
Acids Carbonic,
caffeic, caffeoylmalic, chlorogenic, formic, silicic, citric, fumaric,
glyceric, malic, oxalic, phosphoric, quinic, succinic, threonic and
threono-1,4-lactone.(1)
Amines Acetylcholine,
betaine, choline, lecithin, histamine, serotonin(2) and a glycoprotein.(3)
Flavonoids Flavonol
glycosides (e.g. isorhamnetin, kaempferol, quercetin).(4)
Inorganics Up
to 20% minerals, including calcium, potassium and silicon.
Lignans Several
lignans, including (_)-secoisolariciresinol.
Other Constituents Choline acetyltransferase,(5)
scopoletin,(4) bsitosterol and tannin
Other Plant Parts The
rhizome contains lectin (Urtica dioica agglutinin) composed of six isolectins,(6,
7) coumarin (scopoletin), triterpenes (b-sitosterol, its glucoside, and six
stearyl derivatives),(8, 9) two phenylpropane derivatives, and six lignans.(10)
COMPOUNDS
COMPOUNDS: STINGING NETTLE FLOWERING PLANT
In the stings of
the fresh plant: histamine,
serotonin, acetylcholine, formic acid, leukotriens (LTB4, LTC4, LTD4)
Flavonoids
(0.7-1.8%): including
rutin, isoquercitrin (0.02%), astragalin, kaempferol-3-O-rutinoside
Silicic acid
(1-4%): partially
water-soluble
Volatile oil: chief components
are ketones, including, among others, 2-methylhept-2-en-6-on
Potassium-ions
(0.6% in the fresh foliage)
Nitrates (1.5 to 3%)
COMPOUNDS: STINGING NETTLE ROOT
Steroids: sterols,
including beta-sitosterol (0.03 to 0.06%), beta-sitosterol-3-O-beta-glucoside (0.03
to 0.5%), (6'-Palmitoyl)-sitosterol-3-0-beta-D-glucoside (0.003%),
7alphahydroxysitosterol (0.001%), 7eta-Hydroxysitosterol (0.001%),
stigmasterol, campesterol, stigmast-4-en-3-one
Lectins (0.1%): UDA (Urtica dioica
Agglutinin, isolectine mixture)
Polysaccharides:
glucans,
glucogalacturonans, acidic arabi-'nogalactans water-soluble with
immunostimulating effect)
Hydroxycoumarins:
scopoletin
Lignans: including secoisolariciresinol-9-O-glucoside
(0.004%), neo-olivil (0.003%), neo-olivil-4-O-glucoside (0.004%)
Ceramides
USES
USES
Nettle traditionally has been used as a tea to treat
cough, tuberculosis, and other respiratory conditions, including allergic
rhinitis. It is used as an expectorant, an astringent, a diuretic, and as a
treatment for urinary tract disorders. Nettle is recognized as a bladder
irrigant to reduce blood loss and infl ammation in bladder conditions; benign
prostatic hypertrophy (BPH) (root only). Nettle is also used for arthritis
pain, often in conjunction with low doses of NSAIDs. It is used externally as a
hair and scalp remedy for oily hair and dandruff.
INVESTIGATIONAL USES
Nettle may be used as a diuretic; to lower blood
pressure; and for prostate cancer.
FOOD USE
Nettle
(herbs and leaves) is listed by the Council of Europe as a natural source of
food flavouring (category 1) (see Appendix 3).(G17) Nettle is used in soups and
herbal teas. Previously, in the USA, nettle has been listed by the Food and
Drugs Administration (FDA) as a Herb of Undefined Safety.(G22)
HERBAL USE
Nettle is stated to possess antihaemorrhagic and hypoglycaemic properties. Traditionally, it has been used for uterine haemorrhage, cutaneous eruption, infantile and psychogenic eczema, epistaxis, melaena and specifically for nervous eczema.(G2, G4,G6–G8, G32, G43, G50, G52, G54, G64) The German Commission E approved internal use of nettle leaf as supportive therapy for rheumatic ailments and as irrigation therapy for inflammatory disease of the lower urinary tract and prevention of kidney gravel; internal and external use for rheumatic ailments.(G3) The root is approved for difficulty in urination from benign prostatic hyperplasia.(G3)
Figure 1. Nettle (Urtica
dioica).
Figure 2. Nettle – dried drug substance (leaf).
ACTIONS
Benign Prostatic
Hyperplasia (BPH) Action
Many
studies have been performed to confi rm the BPH action of nettle. Several double-blind
controlled studies showed a considerable improvement in urologic function after
nettle was given. The change in urination occurred within 4 weeks to 6 months,
depending on the study.
Anticancer
Action
One
study has shown that the use of stinging nettle root extract slows the
progression of prostate cancer (Konrad et al, 2000). The rate of slowing
observed was statistically significant.
Analgesic and
Antiinfl ammatory Actions
In
a study, nettle was shown to be an effective and inexpensive treatment for
joint pain (Randall et al, 1999). In another study with similar results
(Riehemann et al, 1999), nettle decreased the infl ammation associated with
rheumatoid arthritis.
Other Actions
Nettle was found to possess diuretic and hypotensive
effects when a continuous perfusion of the aqueous extract was administered to
rats (Tahri et al, 2000).
PHARMACOLOGICAL ACTIONS
IN VITRO AND ANIMAL STUDIES
The
pharmacological properties of nettle have been reviewed.(G50, G52, G56) Information
from these reviews and other sources is summarised below.
Anti-inflammatory activity An
aqueous ethanol extract and Figure 1 Selected constituents of nettle. isolated
caffeoylmalic acid partially inhibited the biosynthesis of arachidonic acid in
vitro.(G52) Nettle extract (0.1 mg/mL) and isolated acid (1 mg/mL) inhibited
5-lipoxygenase-derived biosynthesis of leukotriene B4 by 20.8% and 68.2%, respectively,
and inhibited synthesis of cyclooxygenase-derived prostaglandins (IC50 92 mg/mL
and 38 mg/mL, respectively). The same extract significantly reduced
tumour-necrosis-factor-a (TNFa) and interleukin 1b (IL-1b) concentrations after
lipopolysaccharide (LPS)- stimulated secretion of these proinflammatory
cytokines in human blood.(G52) An aqueous ethanol extract (0.25 mg/mL)
inhibited platelet-activating factor (PAF)-induced exocytosis of elastase from
human neutrophils by 93%, but failed to inhibit biosynthesis of prostaglandins
from [14C]arachidonic acid.(G52) In vitro addition of a commercial preparation
of nettle leaf (IDS-23) to whole human blood resulted in an inhibition of
LPSstimulated TNFa and IL-1b secretion, correlating with drug ingestion. The
same preparation inhibited phytohaemogglutininstimulated production of T helper
cell 1 (Th1)-specific interleukin-2 (IL-2) and interferon-g (IFNg) in culture
in a dosedependent manner up to 50% and 74%, respectively.(11) By contrast, T
helper cell 2 (Th2)-specific interleukin-4 (IL-4) production was stimulated.
The results suggested that the nettle leaf extract acts by mediating a switch
in T helper cell-derived cytokine patterns and may inhibit the inflammatory
cascade in autoimmune diseases such as rheumatoid arthritis.(11) The transcription
factor NF-kB is elevated in several chronic inflammatory diseases and is
responsible for the enhanced expression of some proinflammatory gene products.
A nettle leaf extract (IDS 23) potently inhibited NF-kB activation in a number
of cells, including human T cells, macrophages, epithelial cells and mouse L929
fibrosarcoma cells in vitro.(12) It was proposed that part of the anti-inflammatory
effects of nettle may be due to its inhibitory effect on NF-kB activity. Benign
prostatic hyperplasia activity Several lignans and their metabolites reduce
binding activity of human sex hormonebinding globulin (SHBG) in vitro. Lignans
from nettle are competitive inhibitors of the interaction between SHBG and 5adihydrotestosterone.(
G50) An aqueous extract of nettle root led to a concentration-dependent (0.6–10
mg/mL) inhibition of SHBG interaction with its receptor on human prostatic
membranes. A 20% methanol extract of root inhibited binding capacity of SHBG after
preincubation in human serum.(G50) Subfractions of an aqueous methanol extract
of nettle root inhibited cellular proliferation in benign prostatic hyperplasia
(BPH) tissue. A root extract had a specific and concentrationdependent inhibition
of human leukocyte elastase (HLE) activity in vitro. (HLE is an important
marker in clinically silent genitourinary tract infection and inflammation.)
Root extracts inhibited alternative and classic complementary pathways and significantly
inhibited prostate growth in mice with induced BPH (by 51%, compared with
control; p < 0.003).(G50)
Other Activities CNS-depressant activity has been documented for
nettle. It has been shown to produce a reduction in spontaneous activity in
rats and mice,(13, 14) inhibition of druginduced convulsions, and a lowering of
body temperature in rats.(13) Nettle has been reported to have no effect on the
blood pressure of mice,(14) whereas in cats it has produced a marked hypotensive
effect and bradycardia.(15) Atropine was reported to have no effect on these
latter actions and a mode of action via aadrenoceptors was suggested.(15) Nettle
is stated to contain both hypoglycaemic and hyperglycaemic principles.(16) The
hypoglycaemic component has been termed 'urticin' and nettle has been reported
to lower the blood sugar concentration in hyperglycaemic rabbits.(16) An 80%
ethanolic and an aqueous extract of nettle administered to mice at a dose of 25
mg/kg orally prior to glucose load, led to hypoglycaemia effects.(17) No
diuretic or ion excretion effects were observed in rats after oral
administration of an aqueous extract of nettle (1 g/kg).(14, 18) Dried nettle
had a potassium ion to sodium ion ratio of 63 : 1, whereas an aqueous decoction
had a corresponding ratio of 448 : 1.(19) It was suggested that the high
potassium ion concentration in aqueous decoctions may contribute to their
diuretic activity. Utero-activity has been documented for nettle in pregnant
and non-pregnant mice; betaine and serotonin were stated to be the active
constituents.(20) A nettle extract was reported to be devoid of antifertility
activity following oral administration to mice (250 mg/kg).(21) Analgesic
activity in mice has been documented.(14) Administration of an aqueous extract
(1200 mg/kg) to mice showed resistance to stimulation in the hotplate test at
558C with a 190% increase in reaction time.(14) Conversely, no analgesic activity
was noted in the hotplate test on rats given an ethanolic extract, but the same
extract did reduce the writhing response to phenylquinone after oral (1 g/kg) and
intraperitoneal (500 mg/kg) treatment.(18) The isolectins isolated from the
rhizome are reported to cause non-specific agglutination of erythrocytes, to
induce the synthesis of interferon by human lymphocytes,(6, 7) and have
carbohydratebinding properties.(6, 7) An extract of nettle at a concentration
of 1.2 mg/mL has been reported to be active against L-1210 leukaemic cells in
mice.(22)
CLINICAL STUDIES
Diuretic
effect In an open, uncontrolled study, 32 patients with myocardial or chronic
venous insufficiency were treated with 15 mL of nettle juice three times daily
for two weeks.(G52) A significant increase in daily volume of urine was
observed throughout the study, the volume by day two being 9.2% (p <0.0005)
higher than the baseline value in patients with myocardial insufficiency and
23.9% higher than the baseline value (p <0.0005) in those with chronic venous
insufficiency. It has been proposed that the diuretic activity of aqueous
extracts of nettle may be attributed to the high potassium content.(19) The
reputed diuretic effects of nettle require further investigation.
Arthritis and rheumatism An
open, uncontrolled multicentre study involving 152 patients with various,
mainly degenerative, rheumatic conditions reported that 70% of participants
experienced symptom relief by the end of the three-week treatment period.(G52) In
an open, randomised pilot study involving 37 patients with acute arthritis,
diclofenac 50 mg plus stewed nettle herb 50 g was compared with diclofenac 200
mg.(23) Assessment was based on the decrease in elevated acute phase C-reactive
protein serum concentrations, and clinical signs of acute arthritis. Clinical
improvement was observed in both groups to a similar extent. On the basis of
the findings, it was suggested that nettle herb administration may enhance the
effectiveness of diclofenac in rheumatic conditions. However, this requires
further investigation. In a randomised, double-blind, crossover study, 27
patients with osteoarthritis pain at the base of the thumb and index finger, received
stinging nettle leaf (applied for 30 seconds daily for one week to the painful
area) or white dead nettle (Lamium album) as placebo, followed by a five-week wash-out
period before crossing to the other arm of the study.(24) The results indicated
that reductions in visual analogue scale scores for pain and in a health assessment
questionnaire score for disability were significantly better for the stinging
nettle group, compared with the placebo group (p = 0.026 and p = 0.0027 for
pain and disability, respectively). Benign prostatic hyperplasia A small number
of clinical studies has assessed the effectiveness of nettle preparations in
the treatment of symptoms of benign prostatic hyperplasia (BPH). Several
uncontrolled trials have reported improvements in urological symptoms, compared
with baseline values, following administration of nettle root extract (5 : 1)
600–1200 mg daily for three weeks to 20 months.(G50) Large observational
studies involving patients with BPH who received nettle root extract for two to
three months have reported improvements in various symptoms, such as urinary
frequency, urinary flow and nocturia.(G50) These studies provide justification
for further, rigorous investigation of the effects of nettle in BPH. A placebo-controlled
trial involving 79 patients with BPH assessed the effects of nettle root extract
600 mg daily for six to eight weeks. Compared with placebo, nettle root extract
administration resulted in greater improvements in urinary flow and urine
volume and residual volume.(G50) Another placebocontrolled trial of nettle root
extract 600 mg daily for nine weeks in men with BPH (n = 50) reported a
significant decrease in SHBG concentrations and significant improvement in
micturition volume and maximum urinary flow.(G50)
Rhinitis A
randomised, double-blind, placebo-controlled study assessed the effects of a
freeze-dried preparation of nettle herb in individuals with allergic rhinitis.(25)
Participants received nettle herb 600 mg, or placebo, at the onset of symptoms
over a oneweek period. Assessment was based on daily symptom diaries and global
responses recorded at follow-up visits after one week of therapy. Nettle herb
was rated more highly than placebo in the global assessment, but was rated less
highly on the basis of data from the symptom diaries. It was concluded that
there should be further investigation with a larger sample size and involving a
longer treatment period.
ACTIVITIES
Analgesic
(1; CAN; DEM; PH2); Anesthetic (1; PH2); Antiadrenaline (1; FAD); Antiallergic
(1; MAB); Antiaromatase (1; SHT); Antiarthritic (1; PH2); Antiasthmatic (f; DAW);
Antibacterial (1; FAD; MAB; WOI); Anticancer (1; MAB); Anticomplementary (1;
HH3); Anticonvulsant (1; CAN); Antiedemic (1; FIT68:387; MAB); Antiexudative
(1; HH3); Antihemorrhagic (f; CAN); Antihistaminic (1; WAM); Anti-HIV (1; PH2);
Antihidrotic (f; MAD); Antiinflammatory (1; FIT68:387; MAB; PH2);
Antileukotriene (1; PH2); Antiprostatitic (2; KOM; MAB); Antipyretic (1; CAN);
Antirheumatic (1; MAB; PH2); Antiseptic (1; CRC; PED); Antispasmodic (f; PED);
Antitumor (f; PED); Antiviral (1; MAB; FIT68:387); Aphrodisiac (f; MAD);
Aquaretic (1; SHT); Aromatase Inhibitor (1; HH3); Astringent (1; CRC; MAB; PNC;
SUW); Bitter (f; PED); Bleeding (f; CAN); Bradycardic (1; CAN); CNS Depressant
(1; FAD); CVI (f; APA); Cyclooxygenase Inhibitor (1; MAB; PH2); Cytotoxic (1;
MAB); Depurative (f; BIB; FAD; MAB; PED); Diuretic (2; CRC; PHR; PH2; PNC;
SUW); Elastase Inhibitor (1; MAB); Emmenagogue (f; APA; CRC; KAB; PED; SUW);
Expectorant (f; MAD; PED); Fungicide (1; HH3; MAB); Hematogenic (1; FAD; PH2;
WAM); Hemostat (1; CAN; MAB; MAD; PED); Histaminic (1; FNF); Hyperglycemic (1;
APA; CAN); Hypoglycemic (1; CAN; PNC); Hypotensive (1; CAN); Inteferonigenic
(1; CAN); Lactagogue (f; APA; CRC; MAD); Laxative (f; BGB); 5-Lipoxygenase
Inhibitor (1; MAB; PH2); Litholytic (f; MAD); Mitogenic (f; FAD); Myorelaxant (f;
BGB); Pancreatonic (1; ABS); Rubefacient (f; CRC); Tonic (f; MAB; PNC);
Uterotonic (1; APA; CAN); Vasoconstrictor (f; BIB; CRC); Vermifuge (f; BGB; CRC; KAB; PED; SUW); Vulnerary (f; MAD).
INDICATIONS
Acne
(f; BGB; FEL); Adenoma (1; BGB; SHT); Adenopathy (f; BIB; JLH); Ague (f; DEM;
MAB); Alactea (f; CRC; MAD); Allergy (1; BGB; HH3; MAB; WAM); Alopecia (f; APA;
WOI); Amenorrhea (f; KAB); Anemia (1; CRC; FAD; WAM); Arthrosis (1; DEM; FAD; MAB;
PH2); Asthma (1; DAW; MAB; CRC); Ataxia (f; DEM); BPH (2; BGB; MAB); Bacteria
(1; FAD; MAB; WOI); Bladder Stone (2; PHR; PH2); Bleeding (1; CAN; CRC; DEM;
FEL; MAB; MAD; PED; PNC); BPH (root) (2; KOM; PH2); Bronchosis (1; CRC; MAB;
PED); Bug Bite (1; MAB); Burn (1; BGB; CRC; MAB); Cachexia (f; KAB); Calculus
(f; CRC); Cancer (1; CRC; FAD; MAB; PED); Cancer, breast (1; CRC; JLH); Cancer,
ear (1; CRC; JLH); Cancer, lung (1; CRC; JLH); Cancer, mouth (1; CRC; JLH);
Cancer, spleen (1; CRC; JLH); Cancer, stomach (1; CRC; JLH); Cancer, womb (1;
CRC; JLH); Carcinoma (f; BIB); Catarrh (f; WOI); Childbirth (f; DEM); Cholangosis
(f; CRC); Cholecystosis (f; CRC; FAD; MAB; WOI); Cholera (f; FEL); Colic (f; CRC);
Colitis (f; FEL; MAB); Congestion (f; APA); Constipation (f; BGB; CRC; WOI);
Convulsion (1; CAN); Cramp (f; MAD; PED); CVI (1; BGB); Cystosis (f; FEL); Dandruff
(f; PH2; WOI); Dermatosis (1; BGB; CAN; MAB); Diabetes (f; CRC; MAD; PH2);
Diarrhea (1; BGB; FAD; FEL; MAB); Dropsy (f; BGB; CRC); Dysentery (1; CRC; FAD;
MAB); Dysmenorrhea (f; BGB; APA; MAD; PED); Dyspepsia (f; DEM; MAD); Dyspnea
(f; CRC; KAB); Dysuria (2; KOM; PHR; PH2; SHT); Eczema (f; BGB; CAN; MAB; MAD);
Edema (f; CRC; PH2); Endothelioma (f; BIB; JLH); Enterosis (f; FEL); Epistaxis
(1; BGB; CAN; KAB; MAB); Epithelioma (f; BIB; JLH); Erysipelas (f; CRC); Erythema
(f; CRC); Escherichia (1; WOI); Exanthema (f; MAD); Fever (1; CAN; CEB); Flu
(f; PH2); Fungus (1; HH3; MAB); Gastrosis (f; CRC); Goiter (1; MAB); Gonorrhea
(f; BIB; CRC); Gout (1; FAD; MAB; PH2); Gravel (2; BGB; KOM; MAD; PHR); Hay
Fever (2; APA; MAB); Headache (f; CRC); Hematuria (f; SUW); Hemoptysis (f;
CRC); Hemorrhoid (f; BGB; DEM; PED); Hepatosis (f; HH3); Herpes (f; BGB); High
Blood Pressure (1; CAN); HIV (1; PH2); Hives (f; DEM); Hyperglycemia (1; CAN;
PNC); Hypoglycemia (1; APA; CAN); Infection (1; HH3; MAB); Inflammation (1;
BGB; CRC; FIT68:387; MAB; PH2); Itch (f; DEM); Jaundice (f; CRC; KAB; PED;
SUW); Kidney Stone (2; APA; PHR; PH2); Lethargy (f; KAB); Leukorrhea (f; CRC;
MAD); Malaria (f; BIB; CEB; CRC); Melaena (f; CAN); Menorrhagia (f; SUW);
Mycosis (1; HH3; MAB); Myocardiopathy (1; BGB); Myosis (f; MAB); Nephrosis (f;
CRC; FEL; HH3; PED; SUW); Neuralgia (f; APA; BIB; CRC); Nocturia (1; MAB);
Osteoarthrosis (1; MAB); Osteoporosis (1; JAD); Otosis (f; MAD); Pain (1; CAN;
DEM; PH2); Palsy (f; CEB; CRC; KAB); Paralysis (f; CRC); Parotosis (f; BIB;
JLH); Parturition (f; APA; BGB); Pertussis (f; BIB; CRC); Pharyngosis (f; MAB);
Pleurisy (f; BGB); Pollakisuria (1; BGB); Polyp (f; BIB; JLH); Pregnancy (f;
SKY); Prostatosis (2; PH2; SHT); Rheumatism (2; FAD; KOM; MAB; PHR; PH2);
Rhinosis (1; BGB; HH3; MAB); Sarcoma (f; BIB; JLH); Sciatica (1; CRC; KAB;
MAB); Shigella (1; WOI); Side Ache (f; MAD); Sore Throat (f; CRC); Splenosis
(f; CRC; FAD); Sprain (f; APA; SKJ); Sting (f; CRC); Stomachache (f; DEM);
Stomatosis (f; MAB); Stone (2; KOM; MAD; PHR; PH2; SHT); Swelling (1; BIB; FIT68:387;
DEM; MAB); Tendinitis (f; APA); Tuberculosis (1; CRC; KAB; MAB; SUW); Tumor (f;
CRC; JLH; PED); Uremia (f; BIB); Urticaria (1; MAB); Uterosis (f; BGB; APA;
CAN; KAB); UTI (2; PHR; KOM; PH2; SHT); Vaginosis (f; APA); VD (f; BIB; CRC);
Vertigo (f; BIB; CRC); Virus (1; FIT68:387; MAB; PH2); Worm (f; BGB; CRC; KAB;
PED; SUW); Wound (f; MAB).
INDICATIONS AND
USAGE
STINGING NETTLE
FLOWERING PLANT
·
Infections
of the Urinary Tract
·
Kidney
and Bladder Stones
·
Rheumatism
The drug is used
internally and externally as supportive therapy for rheumatic ailments. It is
used internally as flushing-out therapy for inflammatory diseases of the lower urinary
tract. Also used as irrigation therapy for prevention and treatment of kidney
stones.
Unproven Uses: In folk
medicine, the plant is used internally as a hematogenic remedy, diuretic for
arthritis, rheumatism of the joints and muscles, and as a component of diabetic
teas (this indication is not recommended). Externally, the drug is used as a
hair and scalp remedy against oily hair and dandruff.
STINGING NETTLE ROOT
·
Prostate
Complaints, Irritable Bladder
Preparations of
the root are used for micturition disorders in prostate adenoma stages I to II.
This drug only relieves die symptoms of an enlarged prostate without eliminating
the enlargement itself.
Unproven Uses: In folk medicine,
the root is used for edema, rheumatism, gout and prostatitis.
PRODUCT AVAILABILITY
Capsules, Dried Leaves, Root
Extract, Root Tincture
PLANT PARTS USED: Leaves, Roots, Stems
DOSAGES
DOSAGES
·
Adult PO capsules: 150-300 mg
daily
·
Adult PO tea: place 2 tsp dried
leaves in 8 oz boiling water, steep 15 min; may be taken bid
·
Adult PO tincture: 1⁄2-1 tsp
daily-bid
Osteoarthritis
·
Adult PO crude stinging nettle
leaf: 9 g daily (Jellin et al, 2008)
Allergic rhinitis
·
Adult PO extract: 300 mg tid
(Jellin et al, 2008)
DOSAGES
Dosages
for oral administration (adults) for traditional uses recommended in standard
herbal reference texts are given below.
·
Dried Herb 2–4 g as an infusion three times
daily;(G6, G7) 8–12 g daily;(G3) fresh juice 10–15mL three times daily.(G52)
·
Liquid Extract 3–4mL (1 : 1 in 25% alcohol)
three times daily.(G6, G7)
·
Tincture
2–6mL (1 : 5 in 45% alcohol) three times daily.(G6, G7)
DOSAGES
·
3–4 tsp (~4 g) shoot/cup water
several ×/day (APA); 3–4 tsp (4–6 g)
shoot or leaf in 150 mL boiling water cooled, 3–4 ×/day (APA; MAD); 9 g leaf/day for arthrosis (MAB); 3–6
g dry leaf (PED);
·
4.5 g dry leaf:22 mL alcohol/23
mL water (PED); 4–6 g root/day (APA; KOM); 4–6 g powdered root/cup water (WIC);
4–6 g dry root/day (MAB); 3–6 g root/day or 600–1200 mg/day 5:1 extract for BPH
(MAB);
·
4–9 mL fluid root extract
(1:2)/day (MAB); 2–6 mL root tincture (1:5 in 45% ethanol) 3
×/day (CAN);
·
3–4 tsp (~4.8 g) herb in hot
tea (MAD); 2–4 g dry herb, or in tea, 3 ×/day (CAN); 8–12 g dry herb/day (MAB; SHT);
·
3–4 mL liquid herb extract (1:1
in 25% ethanol) 3 ×/day (CAN); 2.5–5 mL liquid herb
extract (PNC);
·
3–6 mL fluid herb extract (1:2)/day
(MAB); 7–14 mL herb tincture (1:2)/day (MAB); 125 g juice (MAD);
·
1–2 (475 mg) capsules 2–3
×/day; 1 (450 mg) StX capsule 2 ×/day (NH).
DOSAGES
STINGING NETTLE
FLOWERING PLANT
Mode of Administration: Comminuted herb
for infusions and other galenic preparations for internal use; as stinging
nettle spirit for external application. Drug extracts are contained in diuretic
tea mixtures and in blood-purifying teas.
Preparation: To prepare an
infusion, use 1.5 g finely cut herb in cold water, briefly bring to a boil and
steep for 10 minutes, then strain.
Daily Dose: The average daily
dose is 8 to 12 g of drug. Observe ample intake of liquid (minimum 2
liters/day). One cup several times daily as a diuretic (1 teaspoonfiil = 0.8 g drug).
For external application, a tincture/spiritus (1:10) may be administered.
STINGING NETTLE ROOT
Mode of Administration: Comminuted drag
from the root for infusions as well as other galenic preparations for oral use.
Preparation: To prepare an
infusion use 1.5 g coarse powdered drug in cold water, heat to boiling point
for 1 minute, then steep, covered, for 10 minutes, and strain. (1 teaspoonful =
1.3 g drug)
Daily Dose: 4 to 6 g drug.
Tea — 1.5 g coarse powderd drug to water
Dry Extract
— 120 mg twice daily
PRECAUTIONS AND ADVERSE REACTIONS
STINGING NETTLE
FLOWERING PLANT
General: No health hazards
or side effects are known in conjunction with the proper administration of
designated therapeutic dosages. Possible allergic reactions (skin afflictions, edema)
have been observed in rare cases following intake of the drug. Contact urticaria
frequently occurs when skin is exposed to the plant. The urticaria is
accompanied by a stinging sensation that may last as long as 12 hours post exposure
(Oliver, 1991.)
Drug Interactions: Studies have
demonstrated that leaf extracts of Stinging Nettle when used along with
diclofenac, enhance the anti-inflammatory effect of diclofenac.
STINGING NETTLE
ROOT
No health
hazards are known in conjunction with the proper administration of designated therapeutic
dosages. Occasional, mild gastrointestinal complaints may occur as side effects
of drug intake.
CONTRAINDICATIONS, INTERACTIONS, AND SIDE EFFECTS
CLASS
1 (AHP). “Hazards and/or side effects not known for proper
therapeutic dosages” (PH2). None known for herb, rare GI upsets for roots
(KOM). Herbage contraindicated in fluid retention due to reduced cardiac or
renal activity, rarely causing allergic reactions (PHR). Adverse effects of
root: mild GI complaints (occasionally) (AEH). The urtication can be painful
and long-lasting, in some inducing a black-and-blue reaction.
No fatalities are reported in the U.S. CAN cautions that amines
are irritant. Because it is reputed to be abortifacient and to affect the
menstrual cycle, its use in pregnancy and lactation is to be avoided. May
interfere with blood pressure, CNS, and diabetes medication (CAN). Being a
nettle fan, I had never heard of it before and was reluctant to try it when my
friend Vic said that the root tea almost did him in. It’s almost as though he
read the book, “Consumption of nettle tea has caused gastric irritation, a
burning sensation of the skin, oedema, and oliguria” (CAN). Not for use in severely
allergic patients, especially those with tendency toward anaphylaxis (WAM).
Schulz et al. (1998) report on >4000 patients taking 600–1200 mg extract/day
for 6 months. Only 35 showed side effects, 0.65% GI complaints, 9 (0.19%)
dermatosis, and 2 (>0.05%) reporting hyperhydrosis (SHT). No
contraindications are stated (SHT). Varro Tyler cautions against
self-medication with BPH. Whenever treating BPH, a practitioner should be
involved. Base-line levels of PSA should be established before considering an
herbal treatment (JAD). Even JAMA admits that there is no hard proof for
any intervention in BPH. Since hospitals kill 200,000 Americans a year, and
prostate cancer fewer than 50,000, I’ll opt for nettle tea and sitosterol-rich
nuts as the drug of choice for prostate protection.
CONTRA-INDICATIONS,
WARNINGS
Gastrointestinal
irritation has been documented following consumption of nettle tea.
Drug Interactions None
documented. However, the potential for preparations of nettle to interact with
other medicines administered concurrently, particularly those with similar or
opposing effects, should be considered. There is limited evidence from preclinical
studies that nettle preparations have hypoglycaemic, hypotensive and CNS
depressant effects.
Pregnancy and Lactation Nettle is reputed to be an abortifacient and to affect
the menstrual cycle.(G30) Utero-activity has been documented in animal studies.
In view of this and other documented pharmacological activities, the use of
nettle during pregnancy and lactation should be avoided.
CONTRAINDICATIONS
STINGING NETTLE FLOWERING
PLANT
The drug is
contraindicated when there is fluid retention resulting from reduced cardiac or
renal function.
CONTRAINDICATIONS
Pregnancy category is 3;
Breastfeeding category is 2A.
Nettle should not be given to children younger than 2
years of age. Caution should be used when giving nettle to older children and geriatric
clients. Persons with hypersensitivity to nettle should not use it.
SIDE EFFECTS/ADVERSE REACTIONS
GI: Nausea,
Vomiting, Anorexia, Diarrhea, Gastrointestinal Irritation
INTEG: Hypersensitivity
Reactions, Urticaria
MISC: Oliguria,
Edema
INTERACTIONS
Drug
Anticoagulants (heparin, warfarin): Nettle
may decrease the effect of anticoagulants; avoid concurrent use.
CNS depressants (alcohol, barbiturates, sedative/hypnotics, antipsychotics,
opiates): Nettle may lead to increased
central nervous system depression.
Diuretics: Use
of nettle may increase the effects of diuretics, resulting in dehydration and
hypokalemia; avoid concurrent use.
Iron salts: Nettle
tea may interfere with the absorption of iron salts.
Lithium: Nettle
combined with lithium may result in dehydration, lithium toxicity.
Herb
Anticoagulant herbs: Nettle with anticoagulant herbs may decrease anticoagulation.
Sedative herbs: Nettle
may increase central nervous system depression in sedative herbs.
EFFECTS
EFFECTS: STINGING NETTLE FLOWERING PLANT
The fresh leaves
contain acetylcholine, serotin and histamine. The pressed juice (main active
principles scopoletine, beta-sitosterol and caffeoyl malic acid) is diuretic in
combination with sufficient fluid intake. In animal experiments, a local
anaesthetic and analgesic effect has been observed. Caffeoyl acid in vitro,
inhibits 5-lipoxygenasedependent leukotriene synthesis. In various studies, an antirheumatic
and anti-arthritic effect was demonstrated.
Anti-inflammatory Effect - In one study, an
extract from Stinging Nettle leaves (IDS 23) was tested for the ability to inhibit
the biosynthesis of arachidonic acid metabolites in vitro. IDS 23 showed a
strong concentration dependent inhibition of cyclooxygenase derived reactions.
A phenolic acid isolate from the extract inhibited the synthesis of leukotriene
B4 in a concentration dependent manner. The authors concluded that the combination
of these effects may account for the antiphlogistic effects of this extract of Stinging
Nettle (Obertreis, 1996.)
EFFECTS: STINGING NETTLE ROOT
Effects on Prostate Tissue - The root has
been show to cause an increase in the volume of urine, increase of maximum urinary
flow and reduction of residual urine. One study found that an aqueous extract
of the root was the most effective in treating benign prostatic hyperplasia.
The extract inhibited the binding of sex hormone-binding globulin (SHBG) to its
receptor on human prostatic membranes in a dose related manner. Inhibition was
noted at 0.6 mg/mL and complete inhibition was achieved at 10 mg/mL (Hryb et al,
1995.) In a second study, most ligans that were tested were found to have an
affinity for SHBG. The affinity of (-)-3,4-divanillyltetrahydrofuran was found
to be extremely high (Schottner, 1997.)
Viral Inhibition - The (N-acetylglucosamine)
n-specific lectin fron Stinging Nettle was found to be inhibitory to HIV-1,
HIV-2, CMV, RSV and influenza A virus in-vitro at an EC-50 (50% inhibitory concentration)
ranging from 0.3 to 0.9 micrograms/mL (Balzarini, 1992.)
Effects on Systemic Lupus
Erythematosus-like Pathology -Urtica dioica agglutinin (UDA)
treated MRL lpr/lpr mice were shown to be protected from developing clinical
signs of lupus and nephritis (Musette, 1996.)
CLINICAL TRIALS
One randomized,
reference-controlled, multicenter double blind clinical trial compared therapeutic
efficacy of a Sabal and Urtica extract (PRO 160/120) with finasteride in benign
prostatic hyperplasia (Aiken stages I to II). The study involved 543 patients
that were treated for 48 weeks with either the PRO 160/120 extract or finasteride
in a double blind design. The primary marker was the change of maximum urinary
flow after 24 weeks of therapy. Secondary markers included average urinary
flow, miction volume and miction time. Urinary symptoms were recorded by the Intemational-Prostate-Symptom-Score
(I-PSS). There was also a quality of life questionnaire that was developed by
the American Urological Associacion Ameasurement Committee (1991). Results were
similar for both groups. There was an increase in urinary flow rate (1.9 mL with
PRO 160/120; 2.4 mL with finasteride). Urinary flow increase and miction
time decreases
were comparable for both groups. The I-PSS decreased from 11.3 at the start to
8.2 at 24 weeks and 6.5 by week 48 for the PRO 16/120 group, and went from 11.8
to 8.0 and 6.2 respectively for the finasteride group. The life quality scores
went from 7.5 at the start of treatment, to 4.2 in the PRO 160/120 group, and
from 7.7 to 4.1 in the finasteride group. The most notable differences between
the groups were in the lower adverse events categories where the PRO 160/120
group reported less events, in particular imthe areas of diminished ejaculation
volume, erectile dysfunction and headache (Sokeland & Albrecht, 1997.)
SIDE-EFFECTS, TOXICITY
CLINICAL DATA
There
is a lack of clinical safety and toxicity data for nettle and further
investigation of these aspects is required. Postmarketing surveillance studies
involving a total of almost 2000 patients with rheumatoid arthritis treated for
three weeks with nettle leaf extract (IDS-23) administered as an adjuvant to non-steroidal
anti-inflammatory drugs (NSAIDs), or as monotherapy, have reported that the
extract was well-tolerated.(26, 27)
Consumption
of nettle tea has caused gastric irritation, a burning sensation of the skin, oedema
and oliguria.(G22) The
leaves
are extremely irritant in view of their acetylcholine- and histamine-containing
glandular hairs.
PRECLINICAL DATA
An
LD50 in mice following intraperitoneal administration of nettle has been
reported as 3.625 g/kg.(12) The LD50 for intravenous infusion of nettle leaf in
mice has been documented as 1.92 g/kg, and the LD50 for chronic administration
in rats has been stated as 1.31 g/kg.(G50) An ethanolic extract of nettle
(plant part unspecified) showed low toxicity in rats and mice after oral and intraperitoneal
administration at doses equivalent to 2 g/kg.(18)
CLIENT CONSIDERATIONS
ASSESS
·
Assess for hypersensitivity
reactions. If present, discontinue the use of nettle and administer an
antihistamine or other appropriate therapy.
ADMINISTER
·
Recommend that the client
increase his or her intake of potassium-containing foods to prevent
hypokalemia.
·
Instruct the client to store
nettle products in a cool, dry place, away from heat and moisture.
TEACH CLIENT/FAMILY
·
Inform the client that
pregnancy category is 3 and breastfeeding category is 2A.
·
Caution the client not to give
nettle to children younger than 2 years of age, and to use caution when giving
nettle to older children and geriatric clients.
·
Advise the client to use nettle
as a urinary tract irrigant only under the supervision of a qualifi ed
herbalist.
·
Inform the client that stinging
and burning will result if the plant is touched.
PREPARATIONS
PROPRIETARY
SINGLE-INGREDIENT PREPARATIONS
Austria: Uro-POS. Czech Republic: Koprivovy Caj, Koprivova Nat;
Zihlava. Germany: Arthrodynat N; Asendra; Azuprostat Urtica; Bazoton; Flexal Brennessel;
Hox Alpha; Natu-lind; Natu-prosta; Pro-Sabona Uno; Prosta-Truw; Prostaforton; Prostagalen;
Prostaherb N; Prostamed Urtica; Prostata; Prostawern; Rheuma-Hek; Rheuma-Stada;
Uro-POS; Urtivit; utk. Switzerland: Valverde Prostate capsules.
PROPRIETARY
MULTI-INGREDIENT PREPARATIONS
Australia: Cough Relief; Extralife Flow-Care; Infant Tonic; Irontona;
Urapro; Vitatona. Austria: Anaemodoron; Berggeist; Menodoron; Mentopin;
Prostagutt; Prostatonin. Brazil: Prostem Plus. Canada: Allercept; Ultra
Quercitin. Czech Republic: Abfuhr-Heilkrautertee; Diabeticka Cajova
Smes-Megadiabetin; Nephrosal; Perospir; Prostakan Forte; Prostatonin; Pulmoran;
Species Urologicae Planta; Stoffwechseltee N. France: Fitacnol. Germany:
Combudoron; Prostagutt forte; Vollmers praparierter gruner N; Winar. Italy: Biothymus
DS; Prostaplant. Malaysia: Cleansa Plus. Mexico: Prosgutt. Russia: Herbion
Urtica (Гербион Уртика). South Africa: Combudoron; Enzian Anaemodoron Drops;
Menodoron. Spain: Natusor Artilane. Switzerland: Combudoron; Prostagutt-F; Prostatonin;
The a l'avoine sauvage de Vollmer; Tisane Diuretique; Tisane pour les problemes
de prostate. UK: Culpeper Detox Tea; Napiers Echinacea Tea; Summertime Tea
Blend. USA: Prostate Health.
EXTRACTS
Infusion LD50 = 1929 mg/kg ivn rat. HOH extract LD50 = 1721
mg/kg ivn rat. The tea was well tolerated at levels of 1310 mg/kg orally (Bombardelli
and Morazzoni, 1997). LD50 infusion 1310 orl rat (MAB).
(9Z-11E)-13-Hydroxy,9,11-octadecadienoic-acid, 14 octacosanol, oleanolic acid,
secoisolariciresinol, and ursolic acid are listed as weak to moderate
aromatase-inhibitors found in the methanolic root extract. Suggesting synergy,
HH3 gives IC50’s for aromatase inhibition; extract: 338 μg/mL; aqueous extract
= >200 μg/mL; butanolic fractions: 109 μg/mL; ethanolic-fraction 41 μg/mL;
9-hydroxy,10,12- octadecadienoic-acid = 11 μg/mL, and GLA, the compound is so
well represented in another edible weed, evening primrose, at 10 μg/mL (HH3).
Aromatase is a key enzyme in steroid hormone metabolism, and its
inhibition may partially explain the activity of the roots in BPH. The
polysaccharide fraction of the aqueous root extract show prolonged antiedemic
and antiinflammatory activity (40 mg/kg orl rat). Ethanolic extract also inhibits
elastase, a destructive enzyme in the inflammatory process (IC50=68 μg/mL). The
isolectin (UDA), abundant in the roots, may contribute to the antiinflammatory
and antiprostatic activity of the extracts. Aqueous extracts interfere with,
dose-dependently (0.6–10 mg/mL), the binding of dihydrotestosterone to SHBG
(with specific receptors on human prostatic membranes). The alcoholic extract,
UDA, and stigmast-4-en-3-one were inactive. At concentrations of 0.1 mg/mL,
some root extracts inhibited Na+, K+-ATPases 27.6–81.5%. Stigmast-4-en-3-one,
stigmasterol, and campesterol inhibited Na+, K+-ATPases 23–67% at
concentrations of 1-1000 μM. Such inhibition may influence prostate cell
metabolism and growth (Bombardelli and Morazzoni, 1997). Root polysaccharide
extracts anticomplementary (IC50=<50 μg/mL (HH3)). Strange that an herb
should inject so many neuroactive compounds, acetylcholine, choline, formic
acid, histamine, leukotrienes, and serotonin (PH2) into unsuspecting grazers.
REFERENCE
Barnes, J., Anderson, L. A., and Phillipson, J. D. 2007. Herbal
Medicines Third Edition. Pharmaceutical Press. Auckland and
London.
Duke, J. A. with Mary Jo Bogenschutz-Godwin, Judi duCellier, Peggy-Ann K.
Duke. 2002. Handbook of Medicinal Herbs 2nd Ed. CRC Press
LLC. USA.
Gruenwald, J., Brendler,
T., Jaenicke, Ch. 2000. PDR for Herbal
Medicines. Medical Economics Company, Inc. at Montvale, NJ
07645-1742. USA
Linda S-Roth. 2010. Mosby’s Handbook Of Herbs & Natural
Supplements, Fourth Edition. Mosby Elsevier. USA
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