HERBAL
MEDICINE
PLANT
EYEBRIGHT
Euphrasia
officinalis L. (Scrophulariaceae)
by
RETTODWIKART
THENU
EYEBRIGHT
Euphrasia
officinalis L. (Scrophulariaceae)
SUMMARY AND
PHARMACEUTICAL COMMENT
Limited
information is available regarding the constituents of eyebright and it is
unclear which Euphrasia species
is most commonly utilised. In addition, eyebright is also used as a common name
for plants other than Euphrasia species.
Little scientific information was found to justify the reputed herbal uses,
although tannin constituents would provide an astringent effect. The use of
home-made preparations for ophthalmic purposes should be avoided. Little is
known regarding the toxicity of eyebright and, in view of the reported presence
of unidentified alkaloids, it should be used with caution and excessive doses
and prolonged treatment should be avoided.
SPECIES (FAMILY)
Euphrasia officinalis L.
(Scrophulariaceae)
Other
Euphrasia species, including E. rostkoviana Hayne, are used and these may
differ in their chemical constituents. The genus Euphrasia consists of around
450 Euphrasia species and their wild hybrids and these are difficult to
identify botanically.
SYNONYM(S)
Euphrasia
PRODUCT AVAILABILITY
Internal: Fresh herb, infusion, tablets, tincture;
topical: infusion, fl uid extract, fresh herb, lotion, poultice
Plant Part Used:
Flowering plant
PHARMACOPOEIAL AND
OTHER MONOGRAPHS
BHP 1983(G7)
Martindale 35th edition(G85)
LEGAL CATEGORY
(LICENSED PRODUCTS)
Eyebright is not included in the GSL.(G37)
CONSTITUENTS
The
following is compiled from several sources, including General References G2,
G40 and G75. Unless otherwise stated, constituents listed are for E.
officinalis.
Acids
Caffeic acid, ferulic acid.(1)
Alkaloids
Unidentified tertiary alkaloids, choline, steam volatile bases.(1)
Amino
acids Glycine, leucine and valine.
Flavonoids
Four compounds (unidentified). Quercetin and rutin stated to be absent.(1) Quercetin,
quercitrin and rutin have been documented for E. rostkoviana.
Iridoids
Aucubin 0.05%. Additional glycosides have been reported for related Euphrasia species
including catalpol, euphroside, eurostoside, geniposide, ixoroside and
mussaenoside for E. rostkoviana.(2–5)
Phenethyl
glycosides Dehydroconiferyl alcohol-4-b-D-glucoside( 3) and eukovoside
(3,4-dihydroxy-4 phenethyl-O-a-L-rhamnoside( 13)-4-O-isoferuoyl-b-D- glucoside)(4)
from E. rostkoviana.
Tannins
About 12%. Condensed and hydrolysable; gallic acid is among the hydrolysis
products.(1)
Volatile
oils About 0.2%. Seven major and numerous minor components, mainly unidentified;
four of the major compounds are thought to be aldehydes or ketones.(1)
Other
constituents Bitter principle, b-carotene, phytosterols (e.g. b-sitosterol,
stigmasterol),(1) resin, carbohydrates (e.g. arabinose, glucose, galactose) and
vitamin C.
USES
FOOD USE
Eyebright
is listed by the Council of Europe as a natural source of food flavouring
(category N3). This category indicates that eyebright can be added to foodstuffs
in the traditionally accepted manner, although there is insufficient
information available for an adequate assessment of potential toxicity.(G16)
HERBAL USE
Eyebright
is stated to possess anticatarrhal, astringent and antiinflammatory properties.
Traditionally it has been used for nasal catarrh, sinusitis and specifically for
conjunctivitis when applied locally as an eye lotion.(G2, G7, G64)
Figure 1. Eyebright (Euphrasia officinalis).
DOSAGE
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.(G7)
·
Liquid extract 2–4mL (1 : 1 in 25% alcohol) three times daily.(G7)
·
Tincture 2–6 mL (1 : 5 in 45% alcohol) three times daily.(G7)
Dosages
Ophthalmic
·
Adult topical decoction: 5-10
drops (2%) in eye to cleanse, tid-qid
·
Adult topical infusion: soak a
towelette in infusion and apply over eye area prn
Other
·
Adult PO dried herb: 2-4 g tid
as an infusion (Mills, Bone, 2000)
·
Adult PO fl uid extract: 2-4 ml
(1:2 dilution) tid (Mills, Bone, 2000)
·
Adult PO tea: cover 2-3 g fi
nely cut herb with boiling water and let stand 10-15 min, strain, drink
·
Adult PO tincture: 2-6 ml (1:5
dilution) tid (Mills, Bone, 2000)
PHARMACOLOGICAL
ACTIONS
In Vitro And Animal Studies
None
documented for eyebright. Caffeic acid is bacteriostatic,(1) and a purgative
action in mice has been documented for iridoid glycosides.(6) The purgative action
of aucubin is approximately 0.05 times the potency of sennosides, with onset of
diarrhoea stated to occur more than six hours after aucubin administration.( 6)
Tannins are known to possess astringent properties.
Clinical Studies
There
is a lack of clinical research assessing the effects of eyebright and rigorous
randomised controlled clinical trials are required.
SIDE-EFFECTS,
TOXICITY
There
is a lack of clinical safety and toxicity data for eyebright and further
investigation of these aspects is required. Information in older literature
states that doses of as little as 10–60 drops of eyebright tincture could lead
to adverse effects, including mental confusion,(G22) although this requires
confirmation.
SIDE
EFFECTS/ADVERSE REACTIONS
CNS: Confusion, headache, weakness, fatigue
EENT: Nasal congestion, blurred vision, photophobia, lid
swelling, sneezing
INTEG: Hypersensitivity reactions
Interactions
Drug
Antidiabetics: May increase the effects of antidiabetics (theoretical)
when Euphrasia
offi cinalis is taken internally.
Iron salts: Eyebright tea may interfere with the absorption of iron
salts; separate by at least 2 hours.
Figure 2. Eyebright – dried drug substance (herb).
CONTRA-INDICATIONS,
WARNINGS
The
use of eyebright for ophthalmic application has been discouraged.(G60)
Drug
interactions None documented. However, the potential for preparations of
eyebright to interact with other medicines administered concurrently, particularly
those with similar or opposing effects, should be considered.
Pregnancy
and lactation The safety of eyebright has not been established. In view of the
lack of pharmacological and toxicity data, the use of eyebright during
pregnancy and lactation should be avoided.
CONTRAINDICATIONS
Pregnancy category is 3; breastfeeding category is 2A.
Eyebright should not be used by persons with
hypersensitivity to this herb.
CLIENT CONSIDERATIONS
Assess
·
Assess the reason the client is
using eyebright.
·
Assess for hypersensitivity
reactions. If present, discontinue use of eyebright and administer an
antihistamine or other appropriate therapy.
·
Assess the eye for swelling,
lacrimation, redness, and exudate.
Administer
·
Instruct the client to apply
eyebright externally as a compress or drops.
·
Instruct the client to store
eyebright products in a cool, dry place, away from heat and moisture.
TEACH CLIENT/FAMILY
·
Inform the client that
pregnancy is category 3 and breastfeeding is category 2A.
·
If an eye infection is present,
instruct the client to wash hands frequently and not to share towels with
others.
·
Instruct the client on the
correct method for washing the eye with solution.
PREPARATIONS
Proprietary
single-ingredient preparations
UK:
Snore Calm.
Proprietary
multi-ingredient preparations
Australia:
Euphrasia Complex; Euphrasia Compound; Eye Health Herbal Plus Formula 4;
Lifesystem Herbal Plus Formula 5 Eye Relief; Sambucus Complex. Italy: Eulux;
Iridil. Malaysia: Eyebright Plus. Switzerland: Collypan; Oculosan; Tendro. UK: Se-Power;
Summertime Tea Blend; Vital Eyes. USA: Eye Support Formula Herbal Blend.
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.
Linda
S-Roth. 2010. Mosby’s Handbook Of Herbs & Natural Supplements, Fourth
Edition. Mosby Elsevier. USA.
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