Highlights on nutritional and therapeutic value of stinging nettle (Urtica Dioica)

Abstract

Urtica dioica L. is a herbaceous plant belonging to the family of Urticaceae that has been used for centuries against a variety of diseases. Thanks to its high content of nutriments and bioactive compounds like poly phenols, vitamins and minerals, nettle possesses a great nutritional value and a large number of pharmacological effects, including anti-proliferative, anti-inflammatory, antioxidant, analgesic, immunostimulatory, anti-infectious, hypotensive, antiulcer activities and cardiovascular disease prevention. Stinging nettle is considered safe and has been shown to be side effects free, when taken by mouth of up to 18 gram per day. The most common stinging nettle preparations usually include the crude dried powder, dry extract, infusion (herbal tea), decoction or fresh juice. Stinging nettle root is mainly used for mictional disorders related to benign prostatic hyperplasia while the leaves are used for arthritis, rheumatism and allergic rhinitis. This up to date review highlights the current knowledge and scientific advances concerning Urtica dioica. © 2015, International Journal of Pharmacy and Pharmaceutical Science. All rights reserved.

Full text

HIGHLIGHTS ON NUTRITIONAL AND THERAPEUTIC VALUE OF STINGING NETTLE
(URTICA DIOICA)
Review Article
AMAL AIT HAJ SAID1*, IBRAHIM SBAI EL OTMANI2, SANAE DERFOUFI3, ADNANE BENMOUSSA3
1Laboratory of Pharmacognosy, 2Laboratory of Analytical Chemistry and Food Science, 3Laboratory of Medicinal Chemistry, Faculty of
Medicine and Pharmacy of Casablanca, Hassan II University, 19 rue Tarik Ibn Ziad, BP 9154, Casablanca, Morocco
Received: 26 Jul 2015 Revised and Accepted: 02 Sep 2015
Email: amal.aithaj@gmail.com
ABSTRACT
Urtica dioica L. is a herbaceous plant belonging to the family of Urticaceae that has been used for centuries against a variety of diseases. Thanks to
its high content of nutriments and bioactive compounds like poly phenols, vitamins and minerals, nettle possesses a great nutritional value and a
large number of pharmacological effects, including anti-proliferative, anti-inflammatory, antioxidant, analgesic, immunostimulatory, anti-infectious,
hypotensive, antiulcer activities and cardiovascular disease prevention. Stinging nettle is considered safe and has been shown to be side effects free,
when taken by mouth of up to 18 gram per day. The most common stinging nettle preparations usually include the crude dried powder, dry extract,
infusion (herbal tea), decoction or fresh juice. Stinging nettle root is mainly used for mictional disorders related to benign prostatic hyperplasia
while the leaves are used for arthritis, rheumatism and allergic rhinitis. This up to date review highlights the current knowledge and scientific
advances concerning Urtica dioica.
INTRODUCTION
Nettle has been used for over 2,000 y as a natural remedy for its
therapeutic properties. However, it was until the beginning of the
20
Keywords: Urtica dioica, Polyphenols, Urtica Dioica Agglutinin (UDA), Benign prostatic hyperplasia, Rheumatism.
th
Nettle is a herbaceous plant, 1 to 2m tall and perennial with
rhizomes. It belongs to the Urticaceae family in the Rosales order
and the genus Urtica characterized by unicellular stinging hairs.
The erect stems are strong, hairy, mostly unbranched and
quadrangular. They are green in young plants and
purple/reddish in older ones. The leaves are opposite, egg-
shaped, elongated, with a strongly serrated margin and a pointed
tip (fig. 1). The leaves and stems are very hairy and bear many
stinging hairs whose tips come off when touched, transforming
the hair into a needle that injects a stinging liquid. The nettle is
dioecious with separate male and female plants that flower from
June to September. The flowers are unisexual, small, and are
arranged in clusters on slender, branched spikes formed in the
leaf axils. Female flowers are greenish and have a unilocular
ovary with a solitary ovule bearing one style with a brush-like
stigma. Male flowers are yellowish and composed of 4 stamens,
with long elastic filaments, which are bent inwards in the bud.
Stinging nettle produces oval-shaped achenes (one-seeded
fruits) containing tiny dark brown or almost black seeds. The
root system is composed of a taproot which branches into fine
rootlets allowing the tuft nettle to expand [1, 2].
century that its medicinal importance was largely studied and
dramatically enhanced, beginning with the determination of the
chemical structure of the main chemically active agents and their
pharmacological properties. It should be stressed that most of the
indications from traditional medicine have been validated and new
properties have been discovered. Moreover, given its balanced
protein composition and its high content of minerals and vitamins,
nettle has also been shown to be of great nutritional interest.
In Morocco, these medical and nutritional data remain poorly
explored, and the use of nettle is being increasingly neglected both
in the culinary field and in the medical and veterinary areas.
This work highlights the current knowledge and scientific advances
concerning Urtica dioica. We begin with a botanical and a
phytochemical study of the plant and its traditional medical uses in
Morocco. We then look in detail at its nutritional and medical
properties and we describe, at last, its methods of preparation and
use, its toxicity and the use precautions.
Botanical study
Native to Eurasia, nettle was widely distributed throughout all the
temperate regions of the world. It is now found in Europe (more in
northern than in southern Europe), in northern Africa, in Asia and in
northern and southern America where it’s also largely widespread [1].
Table 1 summarizes the most known common names of Urtica dioica.
Traditional medicinal
In Morocco, all parts of the plant are used in traditional
medicine. The whole plant is used as a diuretic, anti-
hypertensive, anti-diabetic, hemostatic, anti-asthenia,
antianemic, antispasmodic, antirheumatic and as a remedy for
headaches and chills [3, 4]. Nettle is also used to treat spleen,
renal and dermal disorders [5]. The seeds are administered
orally for their aphrodisiac and galactagogue effects and other
traditional uses against tuberculosis and kidney stones have
been described [6]. External uses include the treatment of
aphthae, hemorrhoids, scabies and pruritus [4].
uses
Table 1: Common names of Urtica Dioica all around the world
Latin name
Urtica dioïca L. Syn
English names
Nettle; Common nettle; Stinging nettle; Tall nettle; Slender nettle; Greater nettle.
French names
Ortie dioïque; Grande ortie; Ortie piquante; Ortie élevée.
Arabic names
5T
ﺔﻜﻳﺮﺤﻟﺍ5T15T
;
ﺹﺍﺮﻘﻟﺍ
(Hourriga; Kerrass)
Spanish names
Ortiga; Ortiga gran; Ortiga grossa; Ortiga major; Ortiga inayor.
German names
Brennesslbatter; Brennessel-kraut; Nesslkraut; Haarnesselkraut.
International Journal of Pharmacy and Pharmaceutical Sciences
ISSN- 0975-1491 Vol 7, Issue 10, 2015
Innovare
Academic Sciences

Ait Haj Said et al.
Int J Pharm Pharm Sci, Vol 7, Issue 10, 8-14
9
Fig. 1: Urtica dioica, botanical aspects (Pictures from Wikipedia.
Permission granted to copy, distribute and/or modify under the
terms of the GNU Free Documentation License)
Phytochemical
Nettles secondary metabolites have marked pharmacological
properties. The main flavonoids are quercetin, kaempferol and rutin.
These flavonoids have antioxidant and anti-inflammatory properties
that may limit oxidative damage responsible for some chronic
diseases such as cancer, cardiovascular diseases and degenerative
diseases. They have many other effects, such as the inhibition of lipid
peroxidation of liver mitochondria and blood cells and have also
been shown to have hypoglycemic, antibacterial and antiviral
properties [8-10]. The most active flavonoid is quercetin. It has
strong antioxidant and anti-inflammatory actions [11]. It is not only
capable of reducing the incidence of mammary tumors in rats [12,
13] but it also has anti-tumor activity against prostate cancer [14].
Its anti-ulcerogenic activity has also been demonstrated [15, 16].
The antioxidant activity of rutin is similar to that of quercetin [17-
19]. In addition, it has anti-inflammatory, anti-cancer properties and
reduces the cytotoxicity of oxidized bad cholesterol (LDL) [20, 21].
Tannins, caffeic acid, ferulic acid and coumarins also have
antioxidant activity and may protect cells against damage caused by
free radicals [22, 23].
study
The leaves of nettle are rich in flavonoids, as well as phenolic
compounds, organic acids, vitamins and minerals. The root contains
lectins, polysaccharides, sterols and lignans. The stinging action is
due to the liquid contained in nettle’s hairs. This liquid contains at
least three compounds that could be the cause of its allergic
reactions: acetylcholine, histamine and serotonin [2, 7].
Nettle root contains a lectin called Urtica dioica Agglutinin (UDA).
This lectin is somewhat unique. It has a low molecular weight (8 to 9
kDa) and consists of a single polypeptide chain of less than 100
amino acids [24]. The UDA has immunomodulatory activity and
appears to limit the autoimmune manifestations [25]. Table 2
summarizes the chemical composition of nettle’s main parts.
Nutritional value
Nettle leaves are rich in protein, fat, carbohydrates, vitamins,
minerals and trace elements. Proteins make up of 30% of the dry
mass [31]. Furthermore, the protein content of the leaves widely
covers the needs of amino acids, especially the essential amino acids
for humans [33, 38]. Content of mineral substances is about 20% of
the dry mass [31, 45]. Nettle is rich in iron, zinc, magnesium,
calcium, phosphorus and potassium. Leaves content of cobalt, nickel,
molybdenum and selenium have also been determined [32]. The
proportions of different compounds given in the literature are
different. The origin and time of sample collection may be
responsible for that. The maximum and minimum levels of various
compounds are
shown in tables 3 and 4.
Part used
Table 2: Chemical composition of Urtica dioica
References
Chemical composition
Aerial
parts
Flavonoids: Quercetin-3-O-rutinoside (rutin), kaempferol-3-O-rutinoside and isorhamnetin-3-O-glucoside.
[26-28]
Organic acids: Caffeic acid and its esters, ferulic acid, chlorogenic, citric, fumaric and phosphoric acids.
Essential oil: Carvacol, carvone, naphthalene, (E)-anethol, hexahydrofarnesyl acetone, (E)-geranyl acetone, (E)-β-
ionone and phytol.
[26, 29]
Minerals and trace elements: Calcium, Potassium, Magnesium, Phosphorus, Iron, Sulphur, Zinc, Manganese, Copper,
Nickel and Selenium.
[30]
Vitamins: vitamin A (retinol), vitamin B2 (riboflavin), vitamin B5 (pantothenic acid), vitamin B9 (folic acid), vitamin C
(ascorbic acid), vitamin K (phylloquinone).
[31-37]
Other constituents: Tannins, chlorophyll and carotenoids.
[33, 38]
Root
[38]
Acidic polysaccharides: glucans, arabinogalactans and rhamnogalacturonans.
Flavonoids: myricetin, quercetin, kaempferol, quercetin-3-O-rutinoside (rutin), kaempferol-3-O-rutinoside and
isorhamnetin.
[39]
Minerals and trace elements: Calcium, Magnesium, Zinc, Manganese and Copper.
[40]
Lectins: Urtica dioica agglutinin (UDA), consisting of a single-chain polypeptide made of 89 amino acids and rich in
glycines, cysteines and tryptophans.
[34]
Phytosterols: β-sitosterol; β-sitosterol-3-O-β-glucoside, (6'-O-palmitoyl)-sitosterol-3-O-β-D-glucoside; 7β–
hydroxysitosterol; 7α-hydroxysitosterol; 7β-hydroxysitosterol-β-D-glucoside; 7α-hydroxysitosterol-β-glucoside; 24R-
ethyl-5α-cholestane-3β,6α-diol; stigmasterol, campesterol, stigmast-4-en-3-on, hecogenin.
[24, 41]
Lignans: neo-olivil, secoisolariciresinol, dehydrodiconiferyl alcohol, isolariciresinol, pinoresinol, and 3,4-
divanillyltetrahydrofuran.
[27, 39]
Coumarins: Scopoletin
[42, 43]
Fruit
(seeds)
[39, 43]
Fixed oil: saturated and unsaturated fatty acids.
Carotenoids: β-carotene, lutein and violaxantin.
Polysaccharides.
[44]
The vitamin composition is very varied. It contains both fat-soluble
vitamins A, D, E and K, and also significant amounts of water-soluble
vitamins, such as vitamin C and the B vitamins (B1, B2, B3, B9).
Wetherilt found that 100g of fresh leaves contained 0.0l mg vitamin
B1 (thiamine), 0.23 mg of vitamin B2 (riboflavin), 0.62 g of vitamin
B3 (Niacin), 0.068 mg vitamin B6, 238 mg of vitamin C, 5 mg of pro-
vitamin A (β-carotene) and 14.4 mg of vitamin E (α-tocopherol) [38].
This richness in nutrients gives the nettle valuable nutritional and also
pharmacological properties. Trace elements and vitamins strengthen

Ait Haj Said et al.
Int J Pharm Pharm Sci, Vol 7, Issue 10, 8-14
10
the immune system and allow the body to better resist bacterial and
viral infections. The simultaneous presence in nettle of vitamins B1, C,
E, iron, zinc, selenium and manganese contributes to its anti-oxidant
qualities. Nettle has also a remineralizing action, thanks to the
presence of calcium, potassium, silicon and iron. It would be beneficial
in osteoarthritis and osteoporosis. The high potassium content is
another indicator of the protective power of nettle leaves against
cardiovascular disease. The iron content and also the presence of
vitamin C, which increases the bioavailability of iron makes that nettle
is indicated for the treatment of anemia. Additionally, the magnesium
intake it provides reduces the incidence of all forms of stress while
zinc has an anti-inflammatory action.
Another asset of the nettle is chlorophyll. The nettles leaves contain
a significant amount of chlorophyll, around 4.8 mg per gram of dry
leaves [46]. This chlorophyll promotes cleansing and detoxification,
it cleanses the digestive system and fights bloating and bad breath.
In addition, chlorophyll promotes regeneration of cells and activates
wounds healing.
Finally, thanks to their high content of protein, essential amino acids,
vitamins and iron, n
ettle leaves can be an important nutritional
supplement. Therefore, they can be a good remedy for the treatment
of protein-energy malnutrition in malnourished children, pregnant
women, convalescents and the elderly.
Table 3: Nutritional composition of fresh leaves of stinging
nettle [31, 33-36]
Nutritional constituent
Min (%)
Max (%)
65
Water
90
4.3
Proteins
8.9
3.4
Ashes
18.9
7.1
Carbohydrates
16.5
0.7
Lipids
2
3.6
Fibers
5.3
Calories (kcal/
57
100g)
99.7
Table 4: Content of mineral and trace elements (mg/100 g of
dry matter) [31-37]
Minerals and trace elements
mg/100 g of dry matter
Min
Max
Minerals
113.2
Calcium
5090
0.22
Magnesium
3560
29
Phosphorus
75
532
Potassium
917.2
5.5
Sodium
16
Trace elements
0.0084
Cobalt
0.018
0.52
Copper
1.747
3.4
Iron
30.30
0.768
Manganese
5.784
0.4265
Molybdenum
-
0.0732
Nickel
-
0.0027
Selenium
0.0074
0.9
Zinc
3.033
Pharmacological properties
Many research works show that nettle root's components can
interfere with several mechanisms involved in the pathogenesis of
benign prostatic hyperplasia. The antiproliferative effect on prostate
cancer cells of UDA and the methanolic alcoholic root extracts has
been demonstrated in vivo and in vitro [45, 47, 48].
Antiproliferative activity
Lignans from root extract not only inhibit the binding of androgens
to their transporter proteins SHBG (Sex Hormone Binding Globulin),
but also the binding of these proteins to the membrane receptors of
the prostate, thereby inhibiting their proliferative activity on
prostate tissues [42, 45, 49].
The root extract reduces the production of estrogen by aromatase
inhibition, thereby decreasing the conversion of androgens to
estrogens [50]. Also, it was mentioned that root extracts inhibit the
enzymatic activity of the membrane of prostate cells, which would
stop its growth [45, 51]. Clinical studies on a root extracts showed a
significant improvement of the symptoms of benign prostatic
hypertrophy [52-54].
Anti-inflammatory activity
Scientific research has highlighted the nettle's ability to decrease the
inflammatory response, through multiple mechanisms whose
consequences are the reduction of synthesis of lipid mediators and
proinflammatory cytokines. Indeed, leaf extracts inhibit the
biosynthesis of arachidonic acid cascade enzymes, in particular the
cyclo oxygenases COX-1 and COX-2, thereby blocking the
biosynthesis of prostaglandins and thromboxanes [55].
In addition, an inhibitory effect was demonstrated on the NF-kappa
B (nuclear factor kappa-light-chain-enhancer of activated B cells)
system involved in immune, inflammatory and antiapoptotic
responses [56,57] and the PAF (Platelet Activating Factor) [55].
Furthermore, several studies have shown that the extract of the
leaves reduces the release of Interleukins IL-2 and IL-1β, Interferon
γ (IFN γ) and Tumour Necrosis Factors TNF-α and TNF-κ [58,59].
Therefore, the anti-inflammatory effect of nettle leaves suggest that
it may be useful in acute inflammatory diseases but also in chronic
diseases, like rheumatoid arthritis.
The aqueous extract of nettle roots also has anti-inflammatory
activity. Wagner had shown that a polysaccharide fraction of this
extract has an inhibitory effect on the induced rat paw oedema,
comparable to that of indomethacin [60]. The anti-inflammatory
effect is related to the inhibition of cyclo oxygenases and
lipoxygenases, and to cytokines production.
Antioxidant activity
Extracts of nettle have a neutralizing role of reactive oxygen species
(ROS). Their antiradical activity on the superoxide anion O2 °-, the
hydroxyl radical OH ° and nitric oxide radical NO ° was determined
by spectrophotometry. Numerous studies have shown that the
methanolic and ethanolic extracts of leaves have a remarkable
antioxidant effect on the 1,1-diphenyl-2-picrylhydrazyl radical
(DPPH) [9, 61-63].
Chelation of ferrous iron was evaluated using ferrozine, which forms
a red chromophore with the residual iron (FeII-Ferrozine) having an
absorption maximum at 562 nm. The absorbance obtained shows
that nettle has a significant chelating activity of the ferrous ions [63].
Another study conducted on rats treated with carbon tetrachloride
(CCl4
Immunomodulatory activity
), showed that nettle decreased lipid peroxidation and
increased the activity of the antioxidant defense system playing thus
a protective role against hepatotoxicity. This antioxidant activity is
essentially correlated to the phenolic compounds content [9, 64].
Many studies indicate that flavonoids are able to modulate the
immune system. This modulatory effect of the aerial parts of nettle
was studied on mice, using an ethanolic extract at two different
doses (50 and 100 mg/kg), taken orally for 14 d. The activities of
enzymes such as cytochrome P450, lactate dehydrogenase (LDH)
and NADPH-cytochrome P450 reductase showed a significant
decrease while the antioxidant enzymes showed a significant
increase. In addition, the plant has also shown a modulatory effect
on enzymes of the kidney, lung and stomach, such as glutathione-S-
transferase, superoxide dismutase and catalase [65].
Quercetin-3-O-rutinoside, kaempherol-3-O-rutinoside and
isorhamnetin-3-O-glucoside present in the aerial parts of the nettle
contributes to the immunomodulatory activity [2, 66].
Furthermore, the immunomodulatory effect of the UDA isolated
from the roots, has been demonstrated in several studies that
elucidate their action on T cells, macrophages, thymocytes and on
the release of TNFα [60].

Ait Haj Said et al.
Int J Pharm Pharm Sci, Vol 7, Issue 10, 8-14
11
Analgesic and antinociceptive properties
In addition to its anti-inflammatory action, the nettle has an
analgesic effect, proved in vivo in rats and mice. The aqueous extract
of the leaves at the dose of 1200 mg/kg is capable of reducing the
thermal stimulation in the hot plate test at 55 °C and causes a
greater resistance to pain [67].
The antinociceptive effect of the hydroalcoholic extract of nettle
leaves was evaluated through the acetic-acid writhing test and
formalin-induced paw licking test. The results obtained show that
the hydroalcoholic extract significantly reduces in a dose-dependent
manner the nociceptive response in mice and rats. Flavonoids, the
caffeoyl malic acid and the caffeic acid could be responsible for these
analgesic properties [56].
Antiulcer properties
The protective effect of the nettle against gastric ulcers is dose
dependent. The aqueous extract of aerial parts, at doses of 50 and
200 mg/kg protected rats against gastric ulcer, with significant
protection rates ranging from 67.7 to 77.8%. Moreover, this extract
showed analgesic activity against gastric dilatation caused by acetic
acid [63].
Anti-infective properties
The antibacterial properties of various extracts of Urtica dioica
against different bacterial strains were identified by several studies.
In a study conducted on nine bacteria: Citrobacter koseri,
Enterobacter aerogenes, Escherichia coli, Micrococcus luteus, Proteus
mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus,
Staphylococcus epidermidis, and Streptococcus pneumoniae, the
aqueous extract of aerial parts inhibited the growth of all these
bacteria except some strains of Pseudomonas aeruginosa [63].
Another study on 38 microorganisms brought evidence of the
bactericidal effect of organic extracts of the aerial parts. These extracts
inhibited the growth of Acinetobacter calcoaceticus, Bacillus cereus,
Bacillus spizizenii, Bacillus subtilis, Citrobacter freundii, Entrobacter
aerogenes, Erwinia sp., Escherichia coli, Klebsiella pneumoniae,
Micrococcus sp., Saccharomyces cerevisiae, Salmonella paratyphi B,
Serratia marcescens, Methicillin-resistant Staphylococcus aureus
(MRSA) and Vibrio parahaemolyticus. Phenolic compounds in the
nettle would be responsible for this antibacterial effect [68].
The antiviral activity of the nettle was evaluated in vitro [69]. The
selective and powerful inhibitory action of UDA on the intracellular
replication of HIV (HIV-l and HIV-2), respiratory syncytial virus
(RSV), and cytomegalovirus (CMV), was well elucidated [70].
The antimycotic activity on some pathogenic fungi (Alternaria alternata,
Aspergillus flavus, Candida albicans, Ceratcystis ulmi, Fusarium
oxysporum, Fusarium solani, Phoma exigua, Phytophthora carotovora,
Porphyromonas gingivalis, Microsporum cookei, Microsporum gypseum,
Saccharomyces cerevisiae, Trichoderma viride, Trichophyton
mentagophytes and Rizoctonia solani) was also confirmed [63, 71].
Antidiabetic
Furthermore, studies performed on the islets of Langerhans have
demonstrated the stimulatory action of nettle on insulin secretion,
accompanied by a decrease in blood sugar. Tests performed on
normal and diabetic rats after intra peritoneal injection of aqueous
extracts confirmed this result [73].
activity
A study conducted to evluate the anti-diabetic activity in vivo
showed the hypoglycemic effect of aqueous extracts of leaves of
nettle on diabetic rats. These results are explained by the inhibition
of the intestinal absorption of glucose [72].
Intravenous injections of an aqueous extract of the aerial parts of the
nettle, using two concentrations: 4 and 24 mg/kg/h resulted in a
blood pressure drop of 15% and 38% proportionally to the
administered dose. This decrease was correlated with an increase in
diuresis and natriuresis. However, the hypotensive effect was
reversible after one hour if a low concentration (4 mg/kg/h) had
been used, while it persisted when using a high concentration (24
mg/kg/h) [74].
Moreover, root extracts tested on isolated pieces of vaso constricted
aorta showed a relaxant activity. This vasodilator effect is due to the
release of the endothelial nitrogen oxide, potassium channel opening
and a negative inotropic action [75].
Antihypertensive action
Effect on platelet aggregation
Several studies indicate that extracts of nettle strongly inhibit
platelet aggregation. The inhibitory effect of the aqueous extract of
the leaves on platelet aggregation induced by thrombin was clearly
demonstrated. Flavonoids are the main compounds involved in this
activity [76, 77].
Action on hyperlipidemia and atherosclerosis
Daily administration of aqueous extract of Urtica dioica at 150
mg/kg for 30 d, either as part of a normal or high fat diet, caused a
reduction in serum lipids and lipoproteins. Significant decreases in
cholesterol and LDL/HDL ratio (Low Density/High Density
Lipoproteins) were observed [77].
Similarly, administration of an ethanolic extract to
hypercholesterolemic rats, using doses of 100 mg/kg and 300
mg/kg, was responsible for the decreased of cholesterol and LDL
levels [78, 79].
Whereas the LD50 of hydro-alcoholic extracts administered
intraperitoneally is 600 mg/Kg [82]. The toxic dose of the fixed oil of
nettle seeds is greater than 12.8 ml/kg [83]. For chronic oral
application in rats, the DL50 was 1.31g/kg (table 5).
Anti allergic activity
The anti-allergenic activity of the nettle is mainly due to two
mechanisms. In addition to its inhibition of histamine H1 receptors,
nettle inhibits tryptase, consequently reducing mast cell
degranulation and the release of proinflammatory cytokines [55].
In a randomized double-blind study with allergic patients having
allergic rhinitis, an improvement in symptoms was observed after
one week of treatment [80].
Toxicity
Toxicological studies have shown that the LD50 (median lethal dose)
of the aqueous extract of the leaves administered intraperitoneally
in mice is 3.5g/Kg [72]. While the LD50 of the hydro-alcoholic
extract of the leaves administered orally is 5.77 g/Kg [56].
Toxicity studies carried out on the roots have shown that the LD50
values obtained after intravenous injection of an aqueous extract
and an infusion of the roots to rats are respectively 1.721 g/kg and
1.929 g/kg [81].
Table 5: LD50 of different Urtica dioica
extracts
Extracts
Animals tested
Administration routes
LD50 (mg/kg)
References
Leaves
Hydo-alcoholic
Oral
Mice
5770
[56]
Aqueous
Intraperitoneal
Mice
3500
[72]
Root
Hydo-alcoholic
Intraperitoneal
Rats
600
[82]
Aqueous
Rats
1721
Intravenous
[81]
Infusion
Rats
1929
Intravenous
[81]
Infusion
Oral
Rats
>1310
[81]
Seeds
Fixed oil
Intraperitoneal
Mice
>12.8
[83]

Ait Haj Said et al.
Int J Pharm Pharm Sci, Vol 7, Issue 10, 8-14
12
Modes of use and
Thanks to their high content of iron and trace elements, nettle leaves
infusions, tinctures or fresh juices are prescribed to treat anemia and
also for asthenia, convalescence and demineralization states. In
association with the marigold (Calendula officinalis) and curled dock
(Rumex crispus), nettle leaves are used for the treatment of chronic skin
conditions such as eczema, psoriasis and hives [85]. Nettle fresh juice has
a hemostatic effect on the skin and nasal bleeding. It also overcomes the
heavy periods or menorrhagias by reducing their flow [85].
use precautions
Nettle is used by oral and local routes. The most frequently used
preparations in herbal medicine are the total dry powder, dry
extracts, infusions, decoctions and the fresh nettle juice.
Orally, aerial parts are used as diuretics and also in the treatment of
arthritis, rheumatism and gout. Nettle teas are also used in the
treatment of rhinitis and seasonal allergies [84].
Used in mouthwash, nettle is also effective against oral infections
such as aphtha, gingivitis and tonsillitis [86]. External preparations
like fresh nettle poultices are used in cases of acne and to alleviate
arthritic and rheumatic pain [86].
Nettle preparations are also applied externally in hair care against
dandruff and oily hair. Furthermore, the nettle roots, alone or
associated with saw palmetto (Serenoa repens), are used as teas or
extracts in mictional disorders due to benign prostatic hyperplasia
[85].
The adherence to dosage recommendations is essential. The
recommended adult dosage of the dried aerial parts is 1.2 to 18g per
day. For fresh juice, the recommended dose is 15 to 45 ml per day.
Dosages for the dried root preparations are 0.3 to 24g per day.
Recommended dosages and frequency of administration for each
type of preparations are shown in table 6.
Table 6: Recommended doses of Urtica dioica extracts
Parts used
Preparation
Recommended doses
References
Dried aerial parts
Dry powder
6 à 12 g,
8 à 12 g, 2 à 3
per day
2 à 5 g, 3
times daily
3 à 6 g, 3
times daily
[87]
times daily
[84]
[88]
[89]
6 à 12 g,
Infusion
3 à 5 g, 1 à 3
per day
times daily
2 à 5 g, 3
3 à 6 g, 3
times daily
[87]
times daily
[84]
[88]
[89]
2 à 5 g, 3
Decoction
[88]
times daily
Liquid extract
(Dry weight equivalent
6 à 12 g,
)
2 à 5 g, 3
per day
2 à 4 g, 3
times daily
[87]
times daily
[84]
[89]
Tincture
1.4 à 2.8 g,
(Dry weight equivalent)
0.5 à 1g, 3
per day
0.4 à 1.2g, 3
times daily
[87]
times daily
[90]
[88]
Fresh aerial parts
15 ml, 1 à 3
Fresh juice
[84]
times daily
0.3 à 0.6 g,
Dry powder
4 à 6 g,
per day
[91]
per day
[87]
4 à 6 g,
Infusion
per day
4 à 6 g, 3 à 4
[87]
times daily
[84]
4 à 6 g,
Decoction
4 à 6 g, 3 à 4
per day
[87]
times daily
[84]
Liquid extract
1.5 à 7.5 g,
(Dry weight equivalent)
4.5 à 7.5 g,
per day
1 à 1.5g, 3
per day
[87]
times daily
[84]
[88]
Dry extract
2.1 à 8.4 g,
(Dry weight equivalent)
4.5 à 12.1 g,
per day
[84]
per day
[88]
Dried roots
Tincture
3 g,
(Dry weight equivalent)
0.5 à 1g, 3
per day
1 à 1.5g, 3 à 4
times daily
[84]
times daily
[90]
[88]
Despite having anti allergic properties, nettle may cause allergies in
sensitive people. Some rare hypersensitivity reactions like hives,
itching, edema, oliguria and gastralgia have been reported [92, 93].
Furthermore, the use of nettle orally is contraindicated in pregnant
women because of the risk of abortion [94] and in children under 12
because of a lack of clinical studies in this area [1].
CONCLUSION
Notorious for its unpleasant irritant effects, stinging nettle is actually
rich in vitamins and minerals and possesses many medicinal
properties. During the last decades, several studies have focused on
the pharmacological properties and the analysis of the chemical
composition of this plant.
Although its potential benefits are still not entirely defined, many
studies have strengthened its claimed indications from traditional
medicine. Conducted in vitro and in vivo in animals, these studies
have indeed approved many of the nettle pharmacological effects as
antiproliferative, anti-inflammatory, anti-oxidant, analgesic, anti-
ulcer, immunostimulating, anti-infectious, anti-hypertensive and
also as protective against cardiovascular diseases.
In addition, and in regard to its richness in protein, minerals and
vitamins, the stinging nettle provides a proven great nutritional value.
In the perspective of a large medical use, several clinical trials
conducted in humans, confirmed these pharmacological and
nutritional properties. And many toxicological studies proved that
nettle can be considered safe since significant doses, administered
orally in humans, showed no side effects.
CONFLICT OF INTERESTS
Declared None
REFERENCES
1. Ghedira K, Goetz P, Jeune L. Urtica dioica L., Urtica urens et ou
hybrides (Urticaceae). Phytothérapie 2009;7:279-85.
2. Bhuwan CJ, Minky M, Ajudhia NK. Pharmacognostical review of
Urtica dioica L. Int J Green Pharm 2014;8:201-9.

Ait Haj Said et al.
Int J Pharm Pharm Sci, Vol 7, Issue 10, 8-14
13
3. Bnouham M, Mekhfi H, Legssyer A, Ziyyat A. Medicinal plants
used in the treatment of diabetes in morocco. Int J Diabetes
Metab 2002;10:33-50.
4. Hmamouchi M. Les plantes medicinales et aromatiques
marocaines. Morocco: Imprimerie de Fédala; 1999.
5. Daoudi A, Benboubker H, Bousta D, Aarab L. Screening of
fourteen moroccan medicinal plants for immunomodulating
activities. Moroccan J Biol 2008;4-5:24-30.
6. Bellakhdar J. La pharmacopée marocaine traditionnelle:
Médecine arabe ancienne et savoirs populaires. France: Ibis
Press; 1997.
7. Asgarpanah J, Mihajerani R. Phytochemistry and pharmacologic
properties of Urtica dioica L. J Med Plants Res
8. Cushnie TPT, Lamb AJ. Antimicrobial activity of flavonoids. Int J
Antimicrobial Agents 2005;26:343–56.
2012;6:5714-9.
9. Kataki MS, Murugamani V, Rajkumari A, Mehra PS, Awasthi D,
Yadav RS. Antioxidant, Hepatoprotective, and anthelmintic
activities of methanol extract of Urtica dioica L. Leaves. Pharm
Crops 2012;3:38-46.
10. Kumar S, Pande AK. Chemistry and biological activities of
flavonoids: an overview. Sci World J 2013;2013:1-16.
11. Nair MP, Mahajan S, Reynolds JL. The Flavonoid quercetin
inhibits proinflammatory cytokine (Tumor Necrosis Factor
Alpha) gene expression in normal peripheral blood
mononuclear cells via modulation of the NF-κβ system. Clin
Vaccine Immunol
12. 2006;13:319-28.
Verma AK, Johnson JA, Gould MN, Tanner MA. Inhibition of
7,12-Dimethylbenz(a)anthracene-and N-Nitrosomethylurea-
induced rat mammary cancer by dietary flavonol quercetin.
Cancer Res 1988;48:5754-8.
13. Carli CB, de Matos DC, Lopes FC. Isolated flavonoids against
mammary tumour cells LM2. Z Naturforsch C 2009;64:32-6.
14. Nair HK, Rao KVK, Aalinkeel R, Mahajan S, Chawda R, Schwartz
SA. Inhibition of prostate cancer cell colony formation by the
flavonoid quercetin correlates with modulation of specific
regulatory genes. Clin Diagn Lab Immunol 2004;11:63-9.
15. Beil W, Birkholz C, Sewing KF. Effects of flavonoids on parietal
cell acid secretion, gastric mucosal prostaglandin production
and Helicobacter pylori growth. Arzneimittelforschung
1995;45:697-700.
16. Shin JE, Kim JM, Bae EA, Hyun YJ, Kim DH. In vitro inhibitory
effect of flavonoids on growth infection and vacuolation of
Helicobacter pylori. Planta Med 2005;71:197-201.
17. Yang J, Guo J, Yuan J. In vitro antioxidant properties of rutin.
Food Sci Technol 2008;41:1060-6.
18. Torres R, Faini F, Modak B, Urbina F, Labba C, Guerrero J.
Antioxidant activity of coumarins and flavonols from the
resinous exudate of Haplopappus multifolius. Phytochemistry
2006;67:984-7.
19. La Casa C, Villegas I, Alarcan de la Lastra C, Motilva V, Martan
Calero MJ. Evidence for protective and antioxidant properties
of rutin, a natural flavone, against ethanol induced gastric
lesions. J Ethnopharmacol 2000;71:45-53.
20. Selloum L, Bouriche H, Tigrine C, Boudoukha C. Anti-
inflammatory effect of rutin on rat paw oedema, and on
neutrophils chemotaxis and degranulation. Exp Toxicol Pathol
2003;54:313-8.
21. Tian X, Li F, Zhu L, Ye B. Study on the electrochemical behavior
of anticancer herbal drug rutin and its interaction with DNA. J
Electroanal Chem 2008;621:1-6.
22. Sorensen AD, Durand E, Laguerre M. Antioxidant properties
and efficacies of synthesized alkyl caffeates, ferulates, and
coumarates. J Agric Food Chem 2014;62:1253-6.
23. Gülçin İ, Huyut Z, Elmastas M, Aboul-Enein HY. Radical
scavenging and antioxidant activity of tannic acid. Arabian J
Chem 2010;3:43-53.
24. Van Damme EJM, Broekaert WF, Peumans WJ. The Urtica dioica
agglutinin is a complex mixture of isolectins. Plant Physiol
1988;86:598-601.
25. Saul FA, Rovira P, Boulot G, Damme EJ, Peumans WJ. Crystal
structure of Urtica dioica agglutinin, a superantgen presented by
MHC molecules of class I and class II. Structure 2000;8:593-603.
26. Otles S, Yalcin B. Phenolic compounds analysis of root, stalk,
and leaves of nettle. Sci World J 2012;2012:1-12.
27. Chaurasia N, Wichtl M. Flavonol glycoside aus Urtica dioica.
Planta Med 1987;53:432-4.
28. Ellnain-Wojtaszek M, Bylka W, Kowalewski Z. Flavanoids
compounds in Urtica dioica L. Herba Pol 1986;32:131-7.
29. Bakke ILF, Thorsen E, Nordal A. Water soluble acids from
Urtica dioica L. 1978. Medd Nor Farm Selsk 1978;40:181-8.
30. Gül S, Demirci B, Başer KH, Akpulat HA, Aksu P. Chemical
composition and in vitro cytotoxic, genotoxic effects of essential
oil from Urtica dioica L. Bull Environ Contam Toxicol
2012;88:666-71.
31. Pradhan S, Manivannan S, Tamang JP. Proximate, mineral
composition and antioxidant properties of some wild leafy
vegetables. J Sci Ind Res 2015;74:155-9.
32. Mihaljev E, Eivkov-Baloa M, Cupic E, Jakaic S. Levels of some
microelements and essential heavy metals. Acta Pol Pharm
2014;71:385-91.
33. Rutto LK, Xu Y, Ramirez E, Brandt M. Mineral properties and
dietary value of raw and processed stinging nettle (Urtica
dioica L.). Int J Food Sci 2013;2013:1-9.
34. Rafajlovska V, Kavrakovski Z, Siminovska J, Srbinoska M.
Determination of protein and mineralcontents in stinging
nettle. Quality Life 2013;4:26-30.
35. Sultan JI, Rahim IU, Yaqoob M, Mustafa MI, Nawaz H, Akhtar P.
Nutritional evaluation of herbs as fodder source of ruminants.
Pak J Bot 2009;41:2765-76.
36. Sekeroglu N, Ozkutlu F, Deveci M, Dede O, Yilmaz N. Evaluation
of some wild plants aspect of their nutritinal values used as
vegetable in eastern black sea region of Turkey. Asian J Plant
Sci 2006;5:185-9.
37. Kavalali G. The chemical and pharmacological aspects of Urtica.
In: Kavalali GM, (Ed.). Urtica. Therapeutic and Nutritional
Aspects of Stinging Nettles. London, New York: Taylor and
Francis; 2003. p. 47-55.
38. Wetherilt H. Evaluation of Urtica species as potential sources of
important nutrients. Dev Food Sci 1992;29:15-25.
39. Seliya M, Kothiyal P. Urtica dioica (stinging nettle): a review of
its chemical, pharmacological, Toxicological and ethnomedical
properties. Int J Pharm 2014;4:270-7.
40. Wagner H, Willer F, Kreher B. Biologically active compounds
from the aqueous extract of Urtica dioica. Planta Med
1989;55:452-4.
41. Shibuya N, Goldstein IJ, Shafer JA, Peumans WJ, Broekaert WF.
Carbohydrates binding properties of the stinging nettle (Urtica
dioica) rhizome lectin. Arch Biochem Biophys 1986;249:215-24.
42. Schöttner M, Gansser D, Spiteller G. Lignans from roots of
Urtica dioica and their metabolites bind to human sex hormone
binding globulin (SHBG). Planta Med 1997;63:529-32.
43. Chaurasia N, Wichtl M. Phenylpropane und lignane aus der
wurzel von Urtica dioica L. Dtsch Apothek Zeitung
1986;126:1559-63.
44. Guil-Guerreroa JL, Rebolloso-Fuentesa MM, Torija Isasab ME.
Fatty acids and carotenoids from Stinging Nettle (Urtica dioica
L.). J Food Compost Anal
45. Chrubasik JE, Roufogalis BD, Wagner H, Chrubasik S. A
comprehensive review on the stinging nettle effect and efficacy
profiles. Part II: Urticae radix. Phytomedecine 2007;14:568-79.
2003;16:111–9.
46. Rafajlovska V, Najdenova V, Cvetkov L. Influence of some
factors at chlorophyll extraction from stinging nettle (Urtica
Dioica L.). Herba Pol 2001;47:304-14.
47. Lichius JJ, Muth C. The inhibiting effects of Urtica dioica root
extracts on experimentally induced prostatic hyperplasia in the
mouse. Planta Med 1997;63:307-10.
48. Konrad L, Müller HH, Lenz C, Laubinger H, Aumüller G, Lichius
JJ. Antiproliferative effect on human prostate cancer cells by
stinging nettle root (Urtica dioica) extract. Planta Med
2000;66:44-7.
49. Hryb DJ, Khan MS, Romas NA, Rosner W. The effect of extracts
of the roots of the stinging nettle (Urtica dioica) on the
interaction of SHBG with its receptor on human prostatic
membranes. Planta Med 1995;61:31-2.
50. Gansser D, Spiteller G. Aromatase inhibitors from Urtica dioica
roots. Planta Med 1995;61:138-40.
51. Hirano T, Homma M, Oka K. Effects of stinging nettle root
extracts and their steroidal components on the Na+, k(+)-

Ait Haj Said et al.
Int J Pharm Pharm Sci, Vol 7, Issue 10, 8-14
14
ATPase of the benign prostatic hyperplasia. Planta Med
1994;60:30-3.
52. Engelmann U. Therapy for benign prostatic hyperplasia with
nettle liquid. Urology 1996;36:287-91.
53. Schneider T, Rübben H. Stinging nettle root extract in long term
treatment of benign prostatic syndrome. Results of a
randomized, souble-blind, placebo controlled multicenter
study after 12 mo. Urologe A 2004;43:302-6.
54. Safarinejad MR. Urtica dioica for treatment of benign prostatic
hyperplasia: a prospective, randomized, double-blind, placebo-
controlled, crossover study. J Herb Pharmacother 2005;5:1-11.
55. Roschek BJ, Fink RC, McMichael M, Alberte RS, Roschek BJ, Fink
Ryan C, et al. Nettle extract (Urtica dioica) affects key receptors
and enzymes associated with allergic rhinitis. Phytoter Res
2009;23:920-6.
56. Farahpour MR, Khoshgozaran L. Antinociceptive and anti-
inflammatory activities of hydroethanolic extract of Urtica
dioica. Int J Biol Pharm Allied Sci 2015;1:160-70.
57. Riehemann K, Behnke B, Schulze-Osthoff K. Plant extracts from
stinging nettle (Urtica dioica), an antirheumatic remedy, inhibit
the proinflammatory transcription factor NF-kappa B. FEBS
Lett 1999;442:89-94.
58. Konrad A, Mahler M, Arni S, Flogerzi B, Klingelhöfer S, Seibold
F. Ameliorative effect of IDS 30, a stinging nettle leaf extract, on
chronic colitis. Int J Colorectal Dis 2005;20:9-17.
59. Yilmaz B, Basar Ö, Aktas B, Altinbas A. Effects of Urtica dioica
extract on experimental acute pancreatitis model in rats. Int J
Clin Exp Med 2014;7:1313-8.
60. Wagner H, Willer F, Samtleben R, Boos G. Search for the
antiprostatic principle of stinging nettle (Urtica dioica) roots.
Phytomedicine 1994;1:213-24.
61. Khare V, Kushwaha P, Verma S, Gupta A, Srivastava S, Rawat
AKS. Pharmacognostic Evaluation and Antioxidant Activity of
Urtica dioica L. Chin Med 2012;3:128-35.
62. Pourmorad F, Hosseinimehr SJ, Shahabimajd N. Antioxidant
activity, phenol and flavonoid contents of some selected Iranian
medicinal plants. Afr J Biotechnol 2006;5:1142-5.
63. Gulcin I, Kufrevioglu OI, Oktay M, Buyukokuroglu ME.
Antioxidant, antimicrobial, antiulcer and analgesic activities of
nettle (Urtica dioica L.). J Ethnopharmacol 2004;90:205-15.
64. Kanter M, Coskun O, Budancamanak M. Hepatoprotective
effects of Nigella sativa L and Urtica dioica L on lipid
peroxidation, antioxidant enzyme systems and liver enzymes in
carbon tetrachloride-treated rats. World J Gastroenterol
2005;11:6684-8.
65. Ozen T, Korkmaz H. Modulatory effect of Urtica dioica L.
(Urticaceae) leaf extract on biotransformation enzyme systems,
antioxidant enzymes, lactate dehydrogenase and lipid
peroxidation in mice. Phytomedicine 2003;10:405-15.
66. Akbay P, Basaran AA, Undeger U, Basaran N. In vitro
immunomodulatory activity of flavonoid glycosides from Urtica
dioica. Phytother Res 2003;17:34-7.
67. Tita B, Faccendini P, Bello U, Martinoli L, Bolle P. Urtica dioica
L.: pharmacological effect of ethanol extract. Pharmacol Res
1993;27:21-2.
68. Modarresi-Chahardehi A, Ibrahim D, Sulaiman SF, Mousavi L.
Screening antimicrobial activity of various extracts of Urtica
dioica. Rev Biol Trop 2012;60:1567-76.
69. Uncini Manganelli RE, Zaccaro L, Tomei PE. Antiviral activity in
vitro of Urtica dioica L., Parietaria diffusa M. et K. and Sambucus
nigra L. J Ethnopharmacol 2005;98:323-7.
70. Balzarini J, Neyts J, Schols D. The mannose-specific plant lectins
from cymbidium hybrid and epipactis helleborine and the (N-
actylglucosamine)n-specific plant lectin from Urtica dioica are
potent and selective inhibitors of human immunodeficiency
virus and cytomegalovirus replication in vitro. Antiviral Res
1992;18:191-207.
71. Hadizadeh I, Peivastegan B, Kolahi M. Antifungal activity of
nettle (Urtica dioica L.), Colocynth(Citrullus colocynthis L.
Schrad), Oleander (Nerium oleander L.) and Konar (Ziziphus
spina-christi L.) extracts on plants pathogenic fungi. Pak J Biol
Sci 2009;12:58-63.
72. Bnouham M, Merhfour FZ, Ziyyat A, Mekhfi H, Aziz M, Legssyer
A. Antihyperglycemic activity of the aqueous extract of Urtica
dioica. Fitoterapia 2003;74:677-81.
73. Farzami B, Ahmadvand D, Vardasbi S, Majin FJ, Khaghani Sh.
Induction of insulin secretion by a component of Urtica dioica
leave extract in perfused islets of langerhans and its in vivo
effects in normal and streptozotocin diabetic rats. J
Ethnopharmacol 2003;89:47-53.
74. Tahri A, Yamani S, Legssyer A. Acute diuretic, natriuretic and
hypotensive effects of a continuous perfusion of aqueous
extract of Urtica dioica in the rat. J Ethnopharmacol
2000;73:95-100.
75. Testai L, Chericoni S, Calderoneet V. Cardiovascular effects of
Urtica dioica L. (Urticaceae) root extracts: in vitro and in vivo
pharmacological studies. J Ethnopharmacol 2002;81:105-9.
76. El Houari M, Bnouham M, Bendahou M, Aziz M, Ziyyat A,
Legssyer A. Inhibition of Rat Platelet Aggeration by Urtica
dioica leaves extracts. Phytother Res 2006;20:568-72.
77. Daher CF, Baroody KG, Baroody GM. Effect of Urtica dioica
extract intake upon blood lipid profile in the rats. Fitoterapia
2006;77:183-8.
78. Avci G, Kupeli E, Eryavuz A, Yesilada E, Kucukkurt I.
Antihypercholesterolaemic and antioxidant activity assessment
of some plants used as a remedy in Turkish folk medicine. J
Ethnopharmacol 2006;107:418-23.
79. Nassiri-Asl M, Zamansoltani F, Abbasi E, Daneshi MM, Zangivand
AA. Effects of Urtica dioica extract on lipid profile in
hypercholesterolemic rats. Zhongxiyi Jiehe Xuebao 2009;7:428-33.
80. Mittman P. Randomized, double-blind study of freeze-dried
Urtica dioica in the treatment of allergy rhinitis. Planta Med
1990;56:44-7.
81. Baraibar C, Broncano FJ, Lazaro-Carrasco MJ, Rubuelta M,
Villanua L. Acute and chronic toxicity studies on nettle (Urtica
dioica L.). An Bromatol 1983;35:99-103.
82. Pourahmadi M, Jashni HK, Bagheri M, Jahromi AS. The effect of
hydro-alcoholic extract of Urtica dioica root on testes in adult
rats. Life Sci J 2014;11:420-4.
83. Tekin M, Özbek H, Him A. Investigation of acute toxicity, anti-
inflammatory and analgesic effect of Urtica dioica L.
Pharmacologyonline 2009;1:1210-5.
84. ESCOP Monographs. The Scientific Foundation for Herbal
Medicinal Products. 2nd ed. Exeter (UK): European Scientific
Cooperative on Phytotherapy and Thieme; 2003.
85. Chevallier A. Plantes médicinales. France: Grund; 2013.
86. Bellakhdar J. Plantes medicinales du Maghreb et soins de base.
Maroc: Le Fennec; 2006.
87. Mills S, Bone K. The Essential Guide to Herbal Safety. St. Louis
(MO): Elsevier Churchill Livingstone; 2005.
88. Blumenthal M, Goldberg A, Brinkmann J. Herbal medicine:
expanded commission E monographs. Boston (MA): Integrative
Medicine Communications; 2000.
89. Bradley PR. A handbook of scientific information on widely
used plant drugs. British Herbal Compendium. Bournemouth
(UK): British Herbal Medicine Association; 1992.
90. Hoffmann D. Medical Herbalism. Rochester (VT): Healing Arts
Press; 2003.
91. Bradley PR. A handbook of scientific information on widely
used plant drugs. British Herbal Compendium. Bournemouth
(UK): British Herbal Medicine Association; 2006.
92. Tosch U. Medikamentöse behandlung der benignen
prostatahyperplasie. Euromed 1983;6:1-3.
93. Vontobel HP. Ergebnisse einer doppelblindstudie über die
wirksamkeit von ERU-Kapseln in der konservativen
behandlung der benignen Prostatahyperplasie. Urologie
1985;24:49-51.
94. Aswal BS, Bhakuni DS, Goel AK, Kar K. Screening of indian
plants for biological activity: Part X. Indian J Exp Biol
1984;22:312-32.