HERBAL
MEDICINAL
PLANT
-------------------------------------------------
SKULLCAP
Scutellaria lateriflora L. ++
BY
SKULLCAP
((skuhl’kap)
Scutellaria lateriflora L. ++ (Labiatae/Lamiaceae)
SUMMARY AND PHARMACEUTICAL COMMENT
Limited
information has been documented regarding the chemistry of scullcap. Most of
the pharmacological activities reported for other Scutellaria species have been
attributed to the flavonoid constituents. Despite the traditional uses of scullcap
as a sedative and anticonvulsant, there are no documented scientific data to
support these uses.
Commercial
scullcap is commonly recognised to be adulterated with Teucrium species,
notably Teucrium canadense. Herbal preparations stated to contain scullcap may
therefore contain a Teucrium species. Few pharmacological studies have been
undertaken for Teucrium species. Hepatitis has been associated with germander (Teucrium
chamaedrys). Hepatotoxicity has resulted in humans taking commercially
available remedies in the UK which are stated to contain scullcap. In view of
the possibility of contamination, and the lack of pharmacological information,
it would seem advisable to avoid ingestion of scullcap.
DESCRIPTION
MEDICINAL PARTS: The medicinal
part of the plant is the herb.
FLOWER AND FRUIT: The pink or blue
flowers are in short, chiefly lateral false spikes. The calyx is fluffy,
dorsiventral and flattened, with 2 rounded, entire-margined lips. The lower lip
has a helmet-shaped, concave appendage. The 4 ascending stamens have pairs of
ciliated anthers. The fruit is a globular to flattened-ovoid warty nutlet.
LEAVES, STEM AND ROOT: The perennial
herb grows to 60 cm in height and is thickly covered with simple and glandular hairs.
The stem is erect and heavily branched. The foliage leaves are usually ovate to
lanceolate or linear, petioled, entire-margined or crenate.
CHARACTERISTICS: The herb has a
bitter, slightly astringent taste.
HABITAT: The plant is indigenous
to North America and is cultivated in Europe.
PRODUCTION: Scullcap is the aerial
part of 3- to 4-year-old Scutellaria lateriflora and related species, which is
harvested in June and then pulverized.
OTHER NAMES: Blue Pimpernel,
Helmet Flower, Hoodwort, Mad-Dog Weed, Madweed, Quaker Bonnet
SPECIES (FAMILY)
*Scutellaria lateriflora
L.
†S. baicalensis Georgi
(Labiatae/Lamiaceae)
SYNONYM(S)
*Helmet Flower, Hoodwort, Quaker Bonnet, Scutellaria, Skullcap
†S. lanceolaria Miq., S. macrantha Fisch., Huang Qin
ORIGIN
Skullcap is found in North America.
PHARMACOPODIAL AND OTHER MONOGRAPHS
BHP 1996(G9)
Martindale 35th edition(G85)
LEGAL CATEGORY (LICENSED PRODUCTS)
GSL(G37)
CONSTITUENTS
The
following is compiled from several sources, including General References G20
and G60.
Limited
information has been documented regarding the constituents of S. lateriflora and
S. baicalensis.
Flavonoids Apigenin,
hispidulin, luteolin, scutellarein, scutellarin (bitter glycoside).
Iridoids Catalpol.
Volatile oils Limonene, terpineol
(monoterpenes); d-cadinene, caryophyllene, trans-b-farnesene, b-humulene
(sesquiterpenes).
Other constituents Lignin, resin and tannin. S.
baicalensis is reported to contain baicalein, baicalin, chrysin, oroxylin A, skullcapflavone
II and wogonin.(1–3)
Other Scutellaria species The related species
S. galericulata is stated to contain apigenin, baicalein, baicalin,
apigenin-7-glucoside and galeroside (baicalein-b-L-rhamnofuranoside).(4)
USES
USES
Skullcap traditionally has been used to treat seizure
disorders, infl ammation, anxiety, insomnia, nervous tension, spastic disorders,
and high cholesterol.
INVESTIGATIONAL USES
Initial research is available for the use of skullcap
as an antiviral and as a treatment for lung cancer, cerebrovascular accident
(CVA), and embolism.
FOOD USE
Scullcap is not
used in foods. Previously, scullcap has been listed by the Food and Drugs Administration
(FDA) as a Herb of Undefined Safety.(G22)
HERBAL USE
Scullcap
is stated to possess anticonvulsant and sedative properties.( G34, G64) Traditionally,
it has been used for epilepsy, chorea, hysteria, nervous tension states, and
specifically for grand mal epilepsy.(G7) In Chinese herbal medicine, the roots
of S. Baicalensis Georgi have been used traditionally as a remedy for
inflammation, suppurative dermatitis, allergic diseases, hyperlipidaemia and atherosclerosis.
ACTIONS
ACTIONS
ANTICANCER
ACTION
Skullcap has been shown to normalize platelet-mediated
hemostasis in rats with lymphosarcoma (Razina et al, 1989). This action may be
responsible for the antitumor effects of skullcap. Another study documented
antitumor action and antineoplastic toxicity in mice (Razina et al, 1987).
SLEEP DISORDER
TREATMENT
Epidemiologic studies have shown the use of skullcap
for the treatment of sleep disorders (Cauffi eld et al, 1999). Skullcap has
been shown to decrease interleukin-1 and pros ta glan din synthesis (Chung et
al, 1995).
PHARMACOLOGICAL ACTIONS
IN VITRO AND ANIMAL STUDIES
Many
investigations have been undertaken to study the pharmacological actions of S.
baicalensis root. Documented actions have primarily been attributed to the various
flavonoid constituents and include: in vitro inhibition of mast cell histamine
release comparable to disodium cromoglicate for some flavonoids;(1) in vitro cytotoxicity
of scullcap flavone II;(5) in vivo and in vitro inhibition of lipid
peroxidation;(6–8) in vitro inhibition of lipoxygenase and cyclooxygenase
pathways;(9) hypocholesterolaemic activity in rats.(10) This in vivo effect has
been linked to in vitro actions documented for various flavonoids, including prevention
of ethanol-induced hyperlipidaemia,(11) catecholamine-induced lipolysis(10, 11)
and lipogenesis in adipose tissue;(10, 11) there is no pronounced effect on
blood pressure in cats and rabbits.(12) In addition, the latter study found no
CNSdepressant and no antispasmodic activity. However, it did find marked
antibacterial activity against various Gram-positive bacteria (e.g. Bacillus
subtilis, Escherichia coli, Sarcina lutea and Staphylococcus aureus).(13)
CLINICAL STUDIES
There
is a lack of clinical research assessing the effects of scullcap and rigorous
randomised clinical trials are required. Clinical investigation of scutellarin,
a constituent of S. lateriflora, involving 634 cases of cerebral thrombosis,
cerebral embolism, and paralysis caused by stroke has been undertaken. An
overall effective rate of more than 88% was reported following intramuscular,
intravenous or oral administration.(14) However, information from case series
provides only a low level of clinical evidence and the observed effects cannot
be attributed definitively to scutellarin.
ACTIVITIES
Anaphrodisiac
(f; CRC); Antibacterial (f; PED); Anticonvulsant (f; APA); Antioxidant (1;
PH2); Antiinflammatory (1; PH2); Antipyretic (f; CRC; PH2); Antispasmodic (f; APA;
CRC; PH2; SKY); Antiviral (1; WAM); Astringent (f; CRC); Bitter (1; PH2);
Diaphoretic (f; CEB; CRC); Diuretic (f; CEB); Emetic (f; DEM); Emmenagogue (f;
CRC); Hypotensive (f;DAW); Nephrotonic (f; CRC); Nervine (1; CRC; PNC; WAM);
Sedative (f; APA; PH2; SKY; WAM); Tonic (f; APA; CRC; PED; PH2); Tranquilizer
(f; APA).
INDICATIONS
Addiction
(f; APA; CRC); Alcoholism (f; APA; CRC); Anxiety (f; APA; HHB; SKY); Bacteria
(f; PED); Bite (f; CEB); Cancer (f; JLH); Childbirth (f; CRC; DEM); Chorea (f;
CRC; CAN; PH2); Cold (f; PED); Convulsion (f; APA; CEB; CRC); Cramp (f; APA; CEB;
CRC; PH2; SKY); Delirium (f; CEB; CRC); Diarrhea (f; DEM); Dysmenorrhea (f;
APA; CRC; DEM); Dysuria (f; CRC); Embolism (1; CAN); Epilepsy (f; APA; CAN;
CRC; PH2); Fatigue (f; HHB); Fever (f; CEB; CRC; PH2); Headache (f; CRC);
Hepatosis (f; TOM); Hiccup (f; CRC); High Blood Pressure (f; CRC; DAW);
Hydrophobia (f; CRC); Hyperactivity (1; WAM); Hysteria (f; APA; CAN; CRC; PH2);
Inflammation (1; PH2); Insomnia (f; APA; CRC; PH2; SKY; WAM); Malaria (f; CEB);
Mastosis (f; DEM); Nephrosis (f; CRC; TOM); Nerve (f; CRC); Nervousness (f;
APA; CAN; PH2; SKY; WAM); Neuralgia (f; CRC); Neurosis (f; CEB); Pain (f; DEM);
Palsy (f; CRC); Rabies (f; APA; CEB); Rheumatism (f; TOM); Rickets (f; CRC); Smallpox
(f; DEM); Snakebite (f; CRC); Stress (f; CAN; PH2); Stroke (1; CAN); Tetanus
(f; CEB); Throat (f; DEM); Thrombosis (1; CAN); Trevor (f; CEB); Tumor (f;
JLH); Virus (1; WAM); Water Retention (f; CEB).
INDICATIONS AND USAGE
Unproven Uses: The drug was formerly
used for hysteria and nervous tension, epilepsy, chorea, and other nervous
disorders. It has also been used as a bitter tonic and febrifuge.
PRODUCT AVAILABILITY
Capsules, dried herb tea, fl
uid extract, tincture
PLANT PARTS USED: Leaves, roots
DOSAGES
DOSAGES
• Adult PO dried
herb tea: 2 g tid
• Adult PO fluid
extract: 2-4 mL tid (1:1 dilution in 25% alcohol)
• Adult PO tincture:
1-2 mL tid (1:5 dilution in 45% alcohol)
DOSAGES
Dosages
for oral administration (adults) for traditional uses recommended in standard
herbal reference texts are given below.
·
Dried
herb 1–2 g as an infusion three times daily.(G7)
·
Liquid
extract 2–4mL (1 : 1 in 25% alcohol) three times daily.(G7)
·
Tincture 1–2mL
(1:5 in 45% alcohol) three times daily.(G7)
DOSAGES
·
1–2 g herb (PNC); 0.5 oz
herb/pint water (CEB); 2–4 tbsp fresh herb (PED); 1–2 tsp dry herb/cup to 3 ×/day (APA; SKY); 1–2 g dry herb, or in tea, 3 ×/day (CAN;SKY);
·
3–6 g dry herb (PED); 4.5 g dry
herb/22 ml alcohol/22 ml water (PED); 2–4 ml liquid herb extract (PNC); 2–4 ml
liquid herb extract (1:1 in 25% ethanol) 3 ×/day (CAN); 1–2 ml herb tincture (1:5 in 45% ethanol)
3 ×/day (CAN); 2–4 ml herb tincture
3 ×/day (SKY);
·
1–2 droppers herb tincture
(APA); 2–3 (429 mg) capsules 3 ×/day
(APA).
DOSAGES
MODE
OF ADMINISTRATION: The herb is available as a powder and
liquid extract for internal use.
HOW
SUPPLIED:
Capsules
— 425 mg, 429 mg, 430 mg
CONTRAINDICATIONS, INTERACTIONS, AND SIDE
EFFECTS
CLASS 1
(AHP). APA rating = 4 (APA). No
contraindications known (WAM). “Hazards and/or side effects not known for proper
therapeutic dosages” (PH2). Reports of hepatotoxicity may be due to
adulteration with germander, a black eye in itself (AHP). “There is no evidence
to indicate that Scutellaria is toxic when ingested at normal doses” (AHP). The
FDA has suggested that overdose of the tincture causes confusion, convulsions,
giddiness, pulsar irregularities, and twitching (LRNP,
January 1993). The USP, in its proposed monograph of valerian, note that
preparations containing skullcap “caused hepatosis” (the preparation, not
necessarily the valerian). Reported fatality in Norway possibly Scutellaria,
or possibly Teucrium, a frequent adulterant. CAN cautions that a mixed
product (adulteration with Teucrium
spp.) caused hepatotoxicity.
Because of traditional use to eliminate afterbirth and promote menstruation,
and potential hepatotoxicity, its use in pregnancy and lactation is to be
avoided (CAN). Clinical trials with scutellarin in 634 cases of cerebral
embolism, cerebral thrombosis, and stroke paralysis showed an overall effective
rate of more than 88%, following intramuscular, intravenous, or oral
administration (CAN).
CONTRAINDICATIONS
CLASS
1 HERB (ROOT).
Pregnancy category is 3;
Breastfeeding category is 2A.
Skullcap should not be given to children. Persons with
hypersensitivity to skullcap should not use it.
SIDE
EFFECTS/ADVERSE REACTIONS
CNS: Tremors,
confusion, euphoria, seizures, stupor (overdose of tincture only)
CV: Arrhythmias
(overdose of tincture only)
GI: Nausea, vomiting, anorexia, hepatotoxicity
INTEG: Hypersensitivity reactions
INTERACTIONS
Drug
CNS depressants (alcohol, barbiturates):
Skullcap may potentiate sedation
of central nervous system depressants; avoid concurrent use.
Immunosuppressants
(cyclosporine):
Use of skullcap may decrease
the effects of immunosuppressants; avoid concurrent use.
Herb
Sedative herbs: Skullcap with sedative herbs can increase sedation
(theoretical).
INTERACTIONS—CONT’D
Lab Test
ALT, AST, total
and urine bilirubin: Skullcap
may cause increased ALT, AST, total bilirubin, and urine bilirubin.
SIDE-EFFECTS, TOXICITY
There
is a lack of clinical safety and toxicity data for scullcap and further
investigation of these aspects is required.
Symptoms caused by overdosage of scullcap tincture include giddiness,
stupor, confusion and seizures.(G20) Hepatotoxic reactions have been reported after
ingestion of preparations stated to contain scullcap;(15, G20) however,
adulteration of scullcap herb by Teucrium species is recognised and several
cases of hepatitis have been associated with germander (Teucrium chamaedrys).(16)
CONTRA-INDICATIONS, WARNINGS
None
documented. In view of the possible hepatotoxicity associated with scullcap
preparations adulterated with germander, its use is best avoided.
Drug interactions None
documented. However, the potential for preparations of scullcap to interact
with other medicines administered concurrently, particularly those with similar
or opposing effects, should be considered.
Pregnancy and lactation Scullcap is stated to
have been used traditionally to eliminate a mother's afterbirth and to promote menstruation.(G22)
Limited information is known regarding the pharmacological activity and toxicity
of scullcap. In view of this and concerns over hepatotoxicity of adulterated
preparations, scullcap should not be taken during pregnancy and lactation.
CLIENT CONSIDERATIONS
ASSESS
·
Assess for hepatotoxicity,
central nervous system overdose symptoms, and cardiovascular overdose symptoms
(see Side Effects).
·
Assess for hypersensitivity
reactions. If present, discontinue the use of skullcap and administer an
antihistamine or other appropriate therapy.
·
Assess for the use of
immunosuppressants (see Interactions).
ADMINISTER
• Instruct the client to store skullcap 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 skullcap to children.
PREPARATIONS
PROPRIETARY SINGLE-INGREDIENT
PREPARATIONS
Australia:
Albizia Complex; Andrographis Compound; Calmo; Euphrasia Compound; Feminine Herbal
Complex; Goodnight Formula; Nevaton; Pacifenity; Passiflora Complex; Passionflower
Plus; Relaxaplex; Valerian. Canada: Herbal Nerve. UK: Fenneherb Newrelax;
Herbal Indigestion Naturtabs; HRI Calm Life; Inflamol; Napiers Tension Tablets;
Newrelax; Nodoff; Quiet Days; Quiet Tyme; Scullcap & Gentian Tablets;
Sleepezy; St Johns wort Compound; Stressless; Vegetable Cough Remover;
Wellwoman.
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
No comments:
Post a Comment