BILBERRY -- Vaccinium myrtillus L. (Ericaceae)+++

HERBAL

MEDICINAL

PLANT

 

 

 

 

 

 

 

 

 

  

                                                                              

    

  

 

BILBERRY

Vaccini um myrtillus  L. (Ericaceae)+++

 

BY

 

RETTODWIKART THENU

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BILBERRY 

(bil’beh-ree)

 

 

Vaccinium myrtillus  L. (Ericaceae)+++

 

SUMMARY AND PHARMACEUTICAL COMMENT

 

The chemistry of bilberry is well documented and there is good evidence that the anthocyanin constituents are responsible for the pharmacological effects of bilberry.

Data from in vitro and animal studies provide supportive evidence for some of the uses of bilberry. There have been several clinical studies investigating the effects of bilberry in a  range of conditions. However, many studies have been uncontrolled, involved only small numbers of patients and had other methodological flaws. Further, well-designed clinical trials are required to establish the efficacy of bilberry.

There are some limited toxicity and safety data for bilberry which together with data on adverse effects reported in clinical trials provide some support for the safety of bilberry when used at recommended doses in the short term. However, further data on the long-term safety of bilberry use are required and, therefore, excessive use of bilberry should be avoided. Several of the intended uses of bilberry are not suitable for unsupervised self-treatment.

 

Bilberries have been used as a food for many centuries and are valued for their taste and high nutritional content. They are still commonly used to make jams, pies, syrups and beverages. Medicinally, the berries have been used internally to treat diarrhoea and haemorrhoids and externally for inflammation of the mouth and mucous membranes as they have significant astringent activity. According to folklore, World War II British Royal Air Force pilots noticed that their night vision seemed to improve after consuming bilberries or bilberry preserves, sparking a renewed interest in the medicinal properties of the fruits.

 

TRADE NAMES

Bilberry, Bilberry Extract, Bilberry Herb (available from numerous manufacturers,) Time Release Bilberry Power, Standardized Bilberry Extract, Super Bilberry Plus, Bilberry Power, Bilberry Leaf

 

OTHER COMMON NAMES

Baies de myrtille, blaubeeren, dwarf bilberry, European bilberry, European blueberries, huckleberry, hurtleberry, heidelbeeren, petit myrte, whortleberry, wine berry

 

Whortleberry, Blueberry, Burren myrtle, Dyeberry, Huckleberry, Hurtleberry, Wineberry, Black Whortles, Hurts, Bleaberry, Airelle, Trackleberry

 

DESCRIPTION

MEDICINAL PARTS: The medicinal parts are the dried leaves, the ripe, dried fruit and the ripe fresh fruit.

FLOWER AND FRUIT: The flowers are axillary and solitary. They are 4 to 7 mm long, short-pedicled, greenish and tinged with pale pink. The calyx is fused to the ovary, persistent and indistinctly 5-lobed. The corolla is globular-jug-shaped and has 5 tips. There are 8 to 10 stamens, which are enclosed and shorter than the styles. They have glabrous filaments that widen toward the base and 2 horn-like yellow-brown anthers, whose spurred appendage is erect. The fruit is a globular, blue-black, frosted, many-seeded berry with purple pulp.

LEAVES, STEM AND ROOT: The plant is a deciduous, dwarf shrub with sharp-edged, green branches 15 to 50 cm high. The leaves are alternate, ovate or oblong-ovate, acuminate and finely serrate.

HABITAT: The plant is common to central and northern Europe, Asia and North America.

PRODUCTION: The leaves and fruit of Bilberry are collected in the wild from July to August and dried in the shade.

NOT TO BE CONFUSED WITH: Myrtilli folium should not be confused with the fruits of Vaccinium uliginosum.

 

Bilberry is native to Europe and is a member of the Heather Family (Ericaceae). Often confused with blueberries, this is a distinct different berry. It is also known as whortleberry, European blueberry and huckleberry depending on where you live. Wild bilberries have more nutrients than cultivated blueberries and are fabulous for eye health. Although bilberries are wild shrubs, they can be cultivated. Bilberry cultivation works best in cool climates in USDA plant hardiness zones 3 through 8.

 

DISTINGUISHING FEATURES  Bilberries are a low-growing deciduous shrub that can be easily confused with blueberries. Most people can easily distinguish them from blueberries only when the berries are in season. Bilberries and blueberries may look similar on the outside; however, blueberry fruit pulp is light green in color, bilberry fruit pulp is red or purple.

FLOWERS  The flowers are greenish yellowish–reddish, measure 4 to 6 mm (0.16–0.24”) long, are fused, shallowly 4 to 5-lobed. It produces 4 or 8 stamens, and a single carpel. The flowers are solitary in axils. They tend to bloom between May and July depending on latitude. The juicy fruit is spherical, 6 to 8 mm (0.24–0.32") broad, dark blue and glaucous, or black and shiny. The inside is dark red.

LEAVES  The leaves grow alternate and short-stalked. The leaf blade is elliptic–ovate, tapered, finely serrated, and bright green.

HEIGHT  This shrub grows anywhere from 10 to 40 cm (4 to 15”) tall. The stem is erect, abundantly branched, and woody. Older stems are round and brown; the younger stems are more bristly, and green.

HABITAT  The bilberry shrub tends to prefer young and grove-like forest heaths and swamps, yet they can occur in drier areas also. They also are found in acidic, nutrient-poor soils throughout the temperate, arctic, and subarctic regions of the world. Bilberries are one of the most common coniferous forest dwarf shrubs. Bilberries do not like heat.

EDIBLE PARTS  Berries are the edible parts of this shrub. They can be used in jams, pies, ice cream, or anything else in which berries are enjoyed. The fruit can be consumed raw or cooked; a slightly acid flavour is detected if eaten raw. The fruit can be dried. A tea can be made from the leaves and the berries. (https://www.ediblewildfood.com/bilberry.aspx)

 

SPECIES (FAMILY)

Vaccinium myrtillus L. (Ericaceae) +++

 

SYNONYM(S)

Blueberry, Bogberry, Huckleberry, Myrtilus niger Gilib., Whortleberry

 

ORIGIN

Bilberry is found in the central, northern, and southeastern regions of Europe.

 

PHARMACOPODIAL AND OTHER MONOGRAPHS

American Herbal Pharmacopoeia(G1)

BP 2007(G84)

Complete German Commission E(G3)

Martindale 35th edition (Myrtillus)(G85)

Ph Eur 2007(G81)

 

LEGAL CATEGORY (LICENSED PRODUCTS)

Bilberry is not included in the GSL.

 

CONSTITUENTS

The following is compiled from several sources, including General References G2 and G55.

Berries

Flavonoid glycosides Anthocyanins (particularly glycosides of delphinidin, cyanidin, petunidin, peonidin, malvidin),(1, 2) quercetin- 3-glucuronide and hyperoside.(3)

Polyphenols Catechin, epicatechin and tannins.

Other constituents Pectins(1) and vitamin C.

 

Leaves

Flavonoids Quercetin and its glycosides (hyperoside, quercitrin).(1)

Phenolic acids Caffeic, p-coumaric, p-hydroxybenzoic, protocatechuic and melilotic.(4)

Other constituents Tannins and iridoids.(1)

 

CHEMICAL COMPONENTS

COMPOUNDS: BILBERRY LEAF

Catechin tannins (1 to 7%): including oligomeric proanthocyandins

Flavonoids: including among others, avicularin, hyperoside, isoquercitrin, quercitrin, meratine, astragaline

Iridoide monoterpenes: asperuloside, monotropein

Caffeic acid derivatives: chlorogenic acid

Phenolic acids: including among others, salicylic acid, gentisic acid

Quinolizidine alkaloids: myrtine, epimyrtine (hybrids of Vaccinium myrtillus x V. vitis-idaea contain arbutin [hydroquine glucosides]).

 

COMPOUNDS: BILBERRY FRUIT

Fruit acids: including among others, quinic acid (3-5%), malic acid, citric acid

Tannins (5-12%): chiefly catechin tannins, including oligomeric procyanidins

Anthocyanoides (0.1% -0.5%): chief components delphinidine- 3-O-arabinoside, delphinidine-3-O-galactoside, delphinidine- 3-O-glucoside, cyanidin, petunidin, peonidin, malvidin

Flavonoids: including among others, hyperoside, isoquercitrin, quercitrin, astragaline

Iridoids: including asperuloside, onotropein (only in the unripe fruits)

Caffeic acid derivatives: chlorogenic acid

Pectins

 

The fruit contains catechin tannins (up to 10%), invert sugar, fruit acids, flavonol glycosides including astragalin, hyperoside, isoquercitrin and quercitrin, phenolic acids, pectins, triterpenes, and polyphenols such as anthocyanosides. The volatile oil includes methyl salicylate, farnesol, vanillin, myristicin and citronellol. Bilberry also contains vitamin C and chromium, which are suspected of playing a role in its pharmacological activities.

Some of the anthocyanosides are responsible for the deep blue pigment of the fruit (Kahkonen et al 2001). As the fruit ripens, the anthocyanoside content increases. Some commercially available extracts are standardised to anthocyanoside content. Recent research indicates that the anthocyanidin content is particularly high in the pulp of the fruit, however, all parts of the fruit are potential sources of phenolic compounds (Riihinen et al 2008). Anthocyanin concentration in the fresh fruit is approximately 0.1–0.5%, while concentrated bilberry extracts are usually standardised to 25% anthocyanins (Ichiyanagi et al 2004, Zhang et al 2004).

 

Clinical note — Tannins

Tannins are polyphenolic compounds that have an affinity for proteins. They also complex with alkaloids and therefore should not be mixed with alkaloid-containing herbs. Anthocyanosides are condensed tannins. When they come into contact with mucous membranes they have an astringent action, making the mucosa less permeable. This activity has been used therapeutically in a variety of ways. Taken internally, herbs with a high tannin content such as bilberry have been used to treat diarrhoea; applied externally, a styptic action occurs that reduces blood loss.

 

 

USES

USES

Bilberry has been used to improve night vision; to prevent cataracts, macular degeneration, and glaucoma; to treat varicose veins and hemorrhoids; to prevent hemorrhage after surgery; and to prevent and treat diabetic retinopathy and myopia. Other uses for bilberry include decreasing diarrhea, dyspepsia in adults or children, controlling insulin levels, as a diuretic and as a urinary antiseptic.

 

FOOD USE

Bilberries are used in foods.(1) Bilberry is listed by the Council of Europe as a natural source of food flavouring (category N1). This category indicates that there are no restrictions on the use of bilberry in foods.(G16)

 

HERBAL USE

Bilberry is stated to possess astringent, tonic and antiseptic properties and has traditionally been used in the treatment of diarrhoea, dysentry, haemorrhoids, gastrointestinal inflammations, mouth infections, scurvy and urinary complaints.(1) It has also been used in diabetes, gout and rheumatism and applied locally in eye inflammation, burns and skin infections.(1)

 

 

 

Figure 1. Bilberry (Vaccinium myrtillus).

 

Figure 2. Bilberry – dried drug substance (leaves).

 

 

CLINICAL USE

Bilberry extracts are popular in Europe and have been investigated in numerous clinical trials, primarily in non-English speaking European countries. As a result, many research papers have been published in other languages. To provide a more complete description of the evidence available, secondary sources have been used when necessary.

Non-specific acute diarrhoea

The considerable astringent activity of bilberry provides a theoretical basis for its use in non-specific acute diarrhoea. Commission E approved crude fruit preparations for this indication (Blumenthal et al 2000).

Mild inflammation of the mouth and throat

The considerable astringent, anti-inflammatory and anti-oedema activity of bilberry provides a theoretical basis for its use as a topical application in these indications. Commission E approved this indication (Blumenthal et al 2000).

Haemorrhoids, varicose veins, venous insufficiency

The considerable astringent, anti-inflammatory and anti-oedema activity of bilberry provides a theoretical basis for its use in these conditions. Several human case series and a single-blind trial report significant improvements in lower extremity discomfort and oedema related to chronic venous insufficiency; however, further research is required to confirm these findings (Ulbricht & Basch 2005).

Pregnancy

A bilberry product (Myrtocyan®) was taken at a dose of 320 mg daily in the last trimester by women aged 24–37 years with pregnancy-induced lower extremity oedema and found to significantly improve symptoms of burning and itching, heaviness, pain, diurnal and nocturnal leg cramps, oedema and capillary fragility (Ghiringhelli et al 1978 and reported in Blumenthal 2003).

Ophthalmic conditions

Bilberry preparations have been used to improve poor night vision, light adaptation and photophobia, myopia and to prevent or retard diabetic retinopathy, macular degeneration and cataracts. Primarily the collagen-enhancing and antioxidant activities of bilberry provide a theoretical basis for these indications. Visual acuity and light adaptation A systematic review of 12 placebo-controlled trials (5 RCTs and 7 placebo-controlled non-randomised trials) concluded that the anthocyanosides from Vaccinium myrtillus were not effective for improving night vision; however, the authors point out that the potential therapeutic role of these constituents should not yet be dismissed because confounding factors and supportive auxiliary evidence exists (Canter & Ernst 2004). Four of the RCTs showed no positive effects for V. myrtillus anthocyanosides on outcome measures relevant to vision in reduced light whereas the fifth RCT and all seven non-randomised trials reported positive effects on outcome measures relevant to night vision. Seventeen other studies were located by Canter and Ernst but not included in the analysis because they did not contain a placebo group. Sixteen of those studies produced positive results on measures relevant to night vision in either healthy subjects or patients with a range of visual disorders and only one was negative. The authors point out several confounding factors, in particular the wide range of doses, possible geographical variations in extract composition, choice of subject (generally healthy) and methods used to obtain and interpret electroretinograms, which varied between older and newer studies. For example, two of the negative RCTs tested the lowest dose levels of any of the trials: 36 mg daily for acute treatment and ≤ 48 mg for short-term treatment.

A significant improvement in visual performance has been demonstrated for bilberry extract in people with retinitis pigmentosa and haemeralopia (inability to see distinctly in bright light), suggesting that effects may be more pronounced in cases of impaired visual acuity (Gloria & Peria 1966, Junemann 1967).

Glaucoma

In one small study of eight patients, a single oral dose of 200 mg bilberry anthocyanosides was shown to improve glaucoma, as assessed by electroretinography (Caselli 1985).

Retinopathy

In Europe, bilberry anthocyanoside extracts are recognised as highly effective in preventing or treating diabetic retinopathy, with clinical research supporting its use (Lietti et al 1976, Orsucci et al 1983, Perossini et al 1987, Scharrer & Ober 1981). One double-blind study involving 40 patients with diabetic and/or hypertensive retinopathy showed that a dose of bilberry extract (Tegens™) equivalent to 160 mg anthocyanosides taken twice daily for 1 month significantly improved ophthalmoscopic parameters and angiographic parameters (Perossini et al 1987). Another study of 31 subjects with different forms of retinopathy (diabetic retinopathy, retinitis pigmentosa, macular degeneration or haemorrhage due to anticoagulant use) found that treatment with bilberry extract (Difrarel 100™) reduced vascular permeability and the tendency to haemorrhage in all patients (Scharrer & Ober 1981). A small open study by Orsucci et al of 10 subjects with diabetic retinopathy found that 6 months of treatment with bilberry extract (Tegens™) equivalent to 240 mg anthocyanosides daily resulted in reduction or disappearance of haemorrhages and improvement in the retinal picture (Orsucci et al 1983 and reported in Blumenthal 2003).

Myopia

Uncontrolled trials report a beneficial effect of the extract on patients with myopia (Canter & Ernst 2004). Additional studies using purified anthocyanoside oligomers highlight significant improvements in subjective symptoms and objective contrast sensitivity in myopia patients with poor night vision (Lee et al 2005). However, as specificity of source is not provided, this information can only be used in conjunction with the additional supportive evidence listed above.

Cataract

In practice, bilberry has been recommended to delay cataract progression. A case series of 50 elderly subjects with early-stage cataract found that a combination of anthocyanosides extracted from bilberry and vitamin E slowed progression of lens opacities by 97% (Ulbricht & Basch 2005). Placebo- controlled trials are now required to confirm these results.

 

USES

Traditionally, bilberry has been used to treat dysentery, diabetes, gastrointestinal inflammatory conditions, vaginal discharges, haemorrhoids, and to stop lactation. Externally, bilberry preparations have been used to treat wounds, ulcers and skin infections. More recently, other uses include treatment for bleeding gums, nose bleeds, spider veins, capillary fragility, peptic ulcers, Raynaud’s syndrome and venous insufficiency (such as claudication). Additionally, a double-blind placebo-controlled study confirmed that bilberry improves peripheral vascular disorders by improving subjective symptoms after 30 days’ treatment (Mills & Bone 2000).

 

ACTIONS

Research is more extensive for bilberry than for many other commonly used herbs. Areas of research include the use of bilberry for treating circulatory disorders, glaucoma, cataracts, macular degeneration, poor night vision, and diabetic/hypertensive retinopathy. Studies have also focused on its use as an antilipemic.

Ophthalmologic Action

Studies indicate that night vision improved signifi cantly when individuals were given bilberry. Participants experienced improved night visual acuity, improved adjustment to darkness, and restoration of acuity after glare. Further research has confi rmed the findings of the previous studies (Muth et al, 2000). These actions may be due to the affinity of bilberry for the retina. In addition, bilberry may be useful for the prevention and treatment of glaucoma, cataracts, and macular degeneration of the eye (Bravetti, 1989). Chemical components in bilberry may alter the collagen structure of the eye and decrease intraocular pressure. The collagen-stabilizing effects of Vaccinium may offer protection against glaucoma and the development of cataracts and macular degeneration of the eye.

Antidiabetic Action

The anthocyanoside components of bilberry have been shown to decrease hyperglycemia in dogs (Bever et al, 1979). Their effect is somewhat weaker than that of insulin. However, a single dose has an extended duration of up to several weeks (Bever et al, 1979).

Other Actions

Some of the other proposed actions of bilberry include its lipid-lowering effect and its ability to treat infl ammatory joint disease, microscopic hematuria, and varicose veins. Studies in rats have shown that the anthocyanosides promote collagen synthesis and inhibit collagen loss. Bilberry also has been studied for its antioxidant effect (Milbury et al, 2007; Bao et al, 2008).

 

MAIN ACTIONS

The pharmacological actions of bilberry have not been significantly investigated in clinical studies, so information is generally derived from in vitro and animal studies or based on known information about key constituents found within the herb. Most of the research undertaken to understand the pharmacology of the herb has focused on the anthocyanoside content.

Antioxidant

Anthocyanosides are the main phenolic constituents in bilberry and have well established antioxidant activity (Kahkonen et al 2001, Roy et al 2002). This activity is believed to be primarily due to their chemical structure (Mozaffarieh et al 2008, Yao et al 2007). Anthocyanosides have exhibited superoxide radical scavenging properties and cytoprotective activity against oxidative damage in animal models (Valentova et al 2007). Reduces ischaemic reperfusion injury Bilberry anthocyanosides have been shown to improve ischaemic damage, preserve capillary perfusion, inhibit increased permeability of reperfusion and save arteriolar tone in an animal model of ischaemic reperfusion injury (Bertuglia et al 1995). Ophthalmic conditions Bilberry’s significant antioxidant activity is believed to be responsible for much of its activity in the eye, in particular, prevention of cataract.

Anti-inflammatory and anti-oedema activity

Biochemical and histochemical data show that the anthocyanins decrease vascular permeability and alter capillary wall dynamics by increasing the endothelium barrier effect via stabilising membrane phospholipids and increasing synthesis of the mucopolysaccharides in the connective ground substance, thus restoring the altered pericapillary sheath (Mian et al 1977). These effects have been demonstrated in animal models for both oral administration and topical application of bilberry anthocyanins (1% alcohol solution) and were seen to be stronger and longer lasting than those of rutin (Lietti et al 1976).

Astringent

The astringent properties of bilberry are well established and attributed to its significant tannin content.

Improves visual function

Epidemiological investigations have indicated that moderate consumption of anthocyanin-containing herbs such as bilberry extract is associated with an improvement of visual function (Hou 2003). Several animal studies suggest a positive effect on dark adaptation (Canter & Ernst 2004). More specifically, bilberry enhances regeneration of rhodopsin in the retina, which is essential for optimal functioning of the rods and therefore light adaptation and night vision (Blumenthal et al 2000). Other possible mechanisms of action in the eye include accelerated modulation of retinal enzyme activity and improved microcirculation (Canter & Ernst 2004). Jang et al 2005 demonstrated that two anthocyanins from bilberry were potent antioxidants that suppressed photo-oxidative processes initiated in retinal pigment epithelial (RPE) cells by A2E, which is associated with ageing and some inherited forms of retinal degeneration (Kim et al 2008).

Gastroprotective activity

In vitro results have found that a specific anthocyanin found in bilberry causes an increase in the efficiency of the gastric mucosal barrier (Cristoni et al 1989). When administered orally in an animal model it retarded the development of gastric ulcers induced by stress, NSAIDs, ethanol, reserpine and histamine (Magistretti et al 1988).

Hypoglycaemic activity

A dried hydroalcoholic extract of bilberry leaf administered orally to streptozotocin-diabetic rats for 4 days decreased plasma glucose levels by 26% (Cignarella et al 1996).

Reduces triglyceride levels

A dried hydroalcoholic extract of bilberry leaf administered orally to streptozotocin-diabetic rats for 4 days decreased plasma triglyceride levels by 39% (Cignarelli et al 1996).

Neuroprotective

Anthocyanoside content is beneficial in reversing the course of neurodegeneration in animals by affecting calcium homoeostasis and improving motor performance (Kolosova et al 2006, Landfield et al 1994).

Anticarcinogenic activity

Preliminary research has found that components of the hexane/chloroform fraction of bilberry exhibit anticarcinogenic activity (Bomser et al 1996). More recently, antiangiogenic activity has also been identified (Roy et al 2002) as well as anticarcinogenic activity via inhibition of the nuclear factor-kappa B activation pathway (Aggarwal et al 2006). One animal study demonstrated significant reduction in colon cancer in animals fed an anthocyanidin mixture derived from bilberry (Cooke et al 2006).

 

OTHER ACTIONS

Bilberry extract inhibits platelet aggregation according to ex vivo tests (Pulliero et al 1989).

 

PHARMACOLOGICAL ACTIONS

Several pharmacological activities have been documented for bilberry, including ophthalmic activity and anti-inflammatory, wound-healing, anti-ulcer, anti-atherosclerotic and vasoprotective properties.(1)

 

IN VITRO AND ANIMAL STUDIES

An anthocyanidin extract of V. myrtillus has been reported to act as a superoxide anion scavenger(1, 5) and as an inhibitor of lipid peroxidation in rat liver microsomes(1, 5, 6) and in mouse liver tissue in vivo,(5) and to inhibit potassium ion loss induced by free radicals in human erythrocytes.(1) V. myrtillus extract is stated to have a potent protective antioxidant action on human low-density lipoproteins (LDLs) in vitro during copper-mediated oxidation.(7) Oxidative activity is recognised as a major process in tissue damage in a variety of pathological conditions, such as atherosclerosis and carcinogenesis. In addition, oxidative stress is thought to be involved in brain ageing and age-related neurodegenerative disease.

A study in rats reported that, compared with rats fed a control diet, dietary supplementation of blueberry (bilberry) extract for eight weeks reversed age-related deficits in several neuronal and behavioural parameters, such as enhancement of dopamine release from striatal slices and a water maze performance test.(8) V. myrtillus anthocyanins inhibit aggregation of human platelets in vitro in a concentration-dependent manner(9) and, in rats, V. myrtillus anthocyanins administered orally at doses ranging from 5–400 mg/kg prolong bleeding time markedly.(10) Inhibition of platelet aggregation has also been reported in humans treated with V. myrtillus anthocyanins (see Clinical studies).(11)

In vitro inhibition of elastase, a proteolytic enzyme involved with elastic fibre and connective tissue degeneration and with some pathological vascular conditions, has been demonstrated in studies using anthocyanins extracted from V. myrtillus.(12) The hypolipidaemic activity of oral administration of extracts of V. myrtillus leaves has been demonstrated in rats.(13, 14) In genetically hyperlipidaemic rats, plasma triglyceride and cholesterol concentrations, but not free fatty acids, decreased significantly.(13) In streptozotocin-induced diabetic rats, plasma glucose concentrations as well as plasma triglyceride concentrations decreased significantly compared with values in control rats.(14)

In further experiments using bilberry and clofibrate, both preparations reduced plasma triglyceride concentrations in a dose-dependent manner in rats fed a hyperlipidaemic diet and in ethanol-treated normolipidaemic rats.(14) Bilberry, however, did not prevent fructose-elicited increases in plasma triglyceride concentrations. Other studies in glucose loaded mice failed to demonstrate hypoglycaemic activity following oral administration of bilberry leaf extract.(15) Several in vitro studies have demonstrated the relaxing effects of V. myrtillus anthocyanins on isolated vascular smooth muscle preparations, including the thoracic vein and splenic and coronary arteries.(16–18) There is evidence that the mechanism for this smooth muscle relaxant effect is via stimulation of prostaglandin release within vessel walls.(19)

Effects of V. myrtillus anthocyanins on enhancing arterial vasomotion (rhythmic variation of arteriole diameter in the microvasular network which influences microvascular blood flow and the formation of interstitial fluid) have been shown in experimental models, including the cheek pouch microcirculation of hamsters.(20) This model has also been used to investigate the effects of V. myrtillus anthocyanins on ischaemia–reperfusion injury.(21) Oral administration for two and four weeks of Myrtocyan, a commercially available product comprising bilberry anthocyanin complex, reduced the increase in capillary permeability, decreased leukocyte adhesion and improved capillary perfusion compared with controls. In rats, oral administration of V. myrtillus anthocyanins for 12 days before the induction of hypertension (by ligature of the abdominal aorta) limited the increase in vascular permeability and maintained a normal blood–brain barrier permeability.(22)

Components of bilberry exhibit potential anticarcinogenic activity in vitro as demonstrated by inhibition of the induction of ornithine decarboxylase (ODC) by the tumour promoter phorbol 12-myristate 13-acetate (TPA).(23) Myrtocyan and one of its anthocyanin constituents have displayed anti-ulcer activity in various experimental models of acute gastric ulcer and in chronic ulcer induced by acetic acid.(24) The mechanism for this may be by potentiation of the defensive barriers of the gastrointestinal mucosa, such as the secretion of gastric mucus or stimulation of cellular regeneration.(24)

Extracts of V. myrtillus leaves have antibacterial activity against several species, including Staphylococcus aureus and Escherichia coli, as determined by the hole-plate diffusion method and the microdilution broth method.(25) V. myrtillus fruit extracts were less active. The pharmacokinetics of V. myrtillus anthocyanins have been studied in rats.(26) Following a single oral administration, plasma anthocyanin concentrations peaked after 15 minutes and declined rapidly within two hours. No hepatic first-pass effect was observed; elimination occurred mostly through the urine and bile.

 

Figure 3. Bilberry – dried drug substance (fruit).

 

 

CLINICAL STUDIES

Clinical studies with extracts of V. myrtillus fruits (berries) have focused mainly on its therapeutic applications in certain ophthalmological conditions and in altered microcirculation and peripheral venous insufficiency.(1)

A study involving 30 healthy subjects with normal platelet aggregation investigated the effects of administration of V. myrtillus anthocyanins (Myrtocyan) (480 mg) daily, ascorbic acid 3 g daily and V. myrtillus anthocyanins plus ascorbic acid on collagen- and ADP-induced platelet aggregation.(11) Platelet aggregation in blood samples taken from participants after 30 and 60 days' treatment was reduced in all subjects compared with baseline values. The reduction in platelet aggregation was greater in subjects who received V. myrtillus anthocyanins alone than in those who received ascorbic acid alone and was most marked in subjects who received both preparations. Platelet aggregation returned to baseline values when tested 120 days after discontinuation of treatment.(11)

Early studies involving healthy subjects and patients with visual disorders who received V. myrtillus extracts alone or in combination with b-carotene and vitamin E reported improvements in night vision and faster adjustment to darkness and restoration of visual acuity following exposure to a bright flash of light.(1) Other studies reported improvements in retinal sensitivity and the visual field in patients with myopia or glaucoma following short- or long-term (six months) treatment with V. Myrtillus anthocyanins.(1) However, none of these studies included a control group, and so the observed effects cannot be attributed to bilberry treatment. Other uncontrolled studies in small numbers of patients with retinal pathologies have reported improvements in retinal function, compared with pretreatment values (e.g. ref. 27).

In a randomised, double-blind, placebo-controlled trial, 40 patients with diabetic and/or hypertensive retinopathy received Myrtocyan (160 mg) twice daily or placebo for one month.(28) At the end of the study, the placebo group received Myrtocyan for one month. It was reported that 77–90% of treated patients experienced improvement compared with the pretreatment period, as determined by ophthalmoscopy and fluorescein fundus angiography.(28) However, there does not appear to have been a statistical comparison between the treatment and placebo groups.

A similar placebo-controlled trial involving 40 patients with earlyphase diabetic retinopathy who received Myrtocyan for 12 months also reported improvements in Myrtocyan-treated patients.(29) In a randomised, double-blind trial involving 51 patients with mild senile cortical cataract who received V. myrtillus anthocyanins plus vitamin E twice daily for four months, treated patients showed significant improvements in lens opacity compared with placebo recipients.(30) Studies involving patients with peripheral vascular disorders of various origins are stated to have demonstrated clinical benefits with V. myrtillus extracts.(1) Other studies in patients with ulcerative dermatitis secondary to post-thrombotic or venous varicose stasis, capillary fragility secondary to liver disorders and other conditions, or chronic venous insufficiency have been reported to have shown improvements in clinical signs and symptoms.(1) However, several of these studies appear to have been uncontrolled (e.g. refs 31–33) and/or included only small numbers of patients (e.g. refs 31 and 32). A double-blind, placebocontrolled study involving 47 patients with peripheral vascular disorders reported reductions in subjective symptoms, such as paraesthesia, pain and heaviness and improved oedema in patients treated with Myrtocyan (480 mg/day) for 30 days.(1) A single-blind study involving 60 patients with venous insufficiency who received Myrtocyan (480 mg/day) or placebo for 30 days reported significant improvements in oedema, paraesthesia, cramp-like pain and pressure sensation in Myrtocyan-treated patients compared with pretreatment values in these patients.(1) V. myrtillus anthocyanins have been investigated in a variety of other disorders. A randomised, double-blind, placebo-controlled trial of V. myrtillus anthocyanins (320 mg/day) taken for three days before menstruation was conducted involving 30 patients with chronic primary dysmenorrhoea.(34) Significant differences between the active treatment and placebo groups were reported for several symptoms investigated, including nausea and vomiting and breast tenderness; there was no effect on headache. In a trial involving 60 patients who had undergone haemorrhoidectomy, participants were randomised to receive V. Myrtillus anthocyanins (320–480 mg/day) postoperatively in addition to usual medical care or to no additional treatment. Reductions in itch and oedema occurred in bilberry recipients, but there were no effects on other symptoms.(35)

Other studies, all of which were uncontrolled, have reported beneficial effects following administration of V. myrtillus extracts in patients with fibrocystic mastopathy (36) and type II diabetes mellitus,(37) in infantile dyspepsia(38) and in pregnant women with lower limb venous insufficiency and acute-phase haemorrhoids.(39)

 

ACTIVITIES

Antiaggregant (1; APA; BGB; MAB; PED; PH2); Anticapillary Fragility (2; BGB; MAB; PED; PH2); Antiedemic (1; BGB; HH2; MAB; PH2); Antiexudative (1; HH2; PH2); Antiherpetic (f; HH2); Antiinflammatory (1; MAB; PED); Antiischemic (1; MAB; PH2); Antioxidant (1; FNF; SKY); Antiplaque (1; HH2); Antipyretic (1; PNC); Antiretinohemorrhagic (1; PH2); Antiseptic (1; APA; FNF; MAD); Antispasmodic (1; PED); Antiulcer (1; APA; MAB; PH2); Antiviral (1; APA; HH2); Astringent (1; APA; MAB; PH2; PNC); Bitter (1; PED); Circulostimulant (1; SKY); Collagen-Protectant (1; PED; PH2); Diuretic (1; PNC); Fungicide (1; HH2); Immunostimulant (1; MAB); Lipolytic (1; PH2); Myorelaxant (f; APA); Phagocytotic (1; MAB); Vasodilator (1; PNC); Vasoprotective (1; BGB; MAB; PH2); Vulnerary (1; PH2).

 

INDICATIONS

Angina (1; APA; BGB); Anorexia (f; MAD); Aphtha (f; MAD); Arthrosis (1; PED; PHR; PH2); Atherosclerosis (2; APA; SKY); Bleeding (f; MAD; PH2); Bruise (1; PED); Burn (f; PH2); Capillary Fragility (2; BGB; MAB; PED; PH2); Cardiopathy (1; BGB; MAB); Cataract (1; APA; SKY); Catarrh (f; MAD); Circulosis (1; SKY); Colitis (1; BGB; MAD); Conjunctivosis (1; PH2); Constipation (3; APA); Cramp (1; PED); CVI (2; APA; MAB); Cystosis (f; MAD); Debility (f; MAD); Dermatosis (f; HH2; MAD; PHR; PH2); Diabetes (1; APA; MAD; PHR; PH2); Diabetic Hypoglycemia (1; TMA); Diabetic Retinopathy (2; MAB; SKY); Diarrhea (3; APA; KOM; MAD; MAM; PH2; SHT); Dropsy (f; MAD); Dysentery (1; MAB; MAD); Dysmenorrhea (2; APA; MAB); Dyspepsia (1; APA; MAB); Eczema (f; MAD); Edema (1; PH2); Encephalosis (1; APA); Enterosis (1; MAD; MAM; PHR; PH2); Epistaxis (2; MAB); Esophagosis (1; MAB); Fever (1; PNC); Flu (1; HH2); Fungus (1; HH2); Gallstone (f; MAD); Gastrosis (f; PHR; PH2); Gingivosis (1; APA; MAD); Glaucoma (2; APA; MAB; PED); Gonorrhea (f; MAD); Gout (f; HH2; PHR; PH2); Hemeralopia (2; MAB); Hemorrhoid (2; BGB; HH2; MAB; PH2); Hepatosis (1; APA); Herpes (f; HH2); High Cholesterol (1; APA); Hyperglycemia (f; APA); Hyperlipidemia (1; PH2); Immunodepression (1; MAB); Impaired Vision (especially at night) (1; PED); Infection (1; HH2; MAB); Inflammation (1; APA; MAB; PED; PH2); Ischemia (1; MAB); Laryngosis (f; MAD); Leukoplakia (f; MAD); Leukorrhea (f; MAD); Maculosis (1; SKY); Mucososis (2; KOM; MAB; PH2; PIP); Mycosis (1; HH2); Myopia (2; FNF; MAB); Nephrosis (f; PHR; PH2); Nyctalopia (2; MAB; PED; PH2); Odontosis (f; MAD); Ophthalmia (1; PH2); Pain (1; MAB); Paraesthesia (1; MAB); Periodontosis (1; PED); Peritonosis (f; MAD); Pharyngosis (2; MAB; PHR; PH2; PIP); Plaque (1; HH2; MAD); Psoriasis (f; MAD); Raynaud’s (1; MAB; PED); Respirosis (f; HH2); Retinosis (2; BGB; MAB); Sore (f; PH2); Sore Throat (2; KOM; PIP; PH2); Stomatosis (2; MAB; MAD; PHR; PH2; PIP); Swelling (1; BGB; HH2; MAB; PH2); Thick Blood (1; APA; BGB; PED); Typhus (f; MAD); Ulcer (1; APA; MAB; PH2); Urethrosis (f; PHR; PH2); Varicosis (1; MAB; PED; SKY); Virus (1; APA; HH2); Vomiting (f; PH2); Water Retention (1; PNC); Wound (1; MAB).

 

INDICATIONS AND USAGE

BILBERRY LEAF

Unproven Uses: Bilberry has been used in Diabetes Mellitus (for prevention and treatment); complaints of the gastrointestinal tract, kidney and urinary tract, arthritis, gout and dermatitis. External uses include inflammation of the oral mucosa, eye inflammation, burns and skin diseases.

 

BILBERRY FRUIT

• Diarrhea

• Inflammation of the mouth and pharynx

Internally, Bilberry is used for nonspecific, acute diarrhea (particularly in light cases of enteritis). Externally the berry is used for mild inflammation of the mucous membranes of mouth and throat.

Unproven Uses: Well constructed clinical studies in humans that give conclusive support for use of Bilberry in the treatment of diabetic retinopathy or as a treatment for inproving night vision are not available. There is moderate support in animal model trials that support the vasoprotective and anti-edema properties of Bilberry. The literature also demonstrates efficacy in animal models for the treatment of diabetes, hyperlipidemia and gastric ulcers. Folk medicine uses include internal use for vomiting, bleeding and hemorroids and external use for poorly healing skin ulcers and wound healing.

 

Clinical note — Cataract

Growing evidence suggests that senile cataract development may in part be linked to the endogenous generation of free radical molecules, such as superoxide derived from oxygen and light in the aqueous humour and lens (Varma & Richards1988, Varma et al 1982, 1994). As such, substances with significant antioxidant activity such as anthocyanins, vitamin C and vitamin E have been investigated as potential prophylactic treatments.

 

PRODUCT AVAILABILITY

Capsules: 60, 80, 120, 450 mg; Fluid Extract; Fresh Berries, Dried Berries; Liquid; Tincture; Dried Roots, Dried Leaves

PLANT PARTS USED: Berries, Roots, Leaves Fruit (Berries), Leaves

 

DOSAGES

 

DOSAGES

Cataracts

·         Adult PO extract: 40-80 mg standardized to 25% anthocyanosides (anthocyanadin) tid (Murray, Pizzorno, 1998)

Diabetes Mellitus

·         Adult PO extract: 80-160 mg standardized to 25% anthocyanosides tid (Murray, Pizzorno, 1998)

Glaucoma

·         Adult PO extract: 80 mg standardized to 25% anthocyanosides tid (Murray, Pizzorno, 1998)

Other

·         Adult PO fresh berries: 55-115 g tid

·         Adult topical decoction: 1⁄8-1⁄4 ounce (5-8 g) of crushed dried fruit in 150 mL of water, boil 10 min, strain, use warm

·         Adult gargle/mouthwash: prepare decoction 10%, rinse or gargle

 

 

DOSAGES

Dosages for oral administration (adults) for traditional uses recommended in standard herbal reference texts are given below.

·         Dried fruit   20–60 g daily as a decoction for the treatment of diarrhoea.(G2)

 

DOSAGES

·         1–2 tbsp crushed fruit/cup water; or 3 tbsp (ca 30 g) dried berries (APA); 20–60 g dry fruit (KOM);

·         12–24 g dry fruit (PED); 20–60 g dry fruit/day (SF); 1/2–1 cup fresh fruit (PED); 100–300 g fresh berry (SHT);

·         1–1.5 tsp fruit (= ~7–10.5 g) cold infusion (MAD); 2–8 mL liquid fruit extract (PNC);

·         3–6 mL/day fluid extract (1:1) (MAB); 1 g leaf/cup tea (HH2); tablet with 50–120 mg (= 20–50 g fruit) (MAB); 2 (470 mg) capsules (StX to contain at least 10 mg anthocyanosides (25% anthocyanosides)) 2 x/day (NH);

·         240–480 mg StX/day (25% anthocyanosides) (SF; SKY); 500 mg StX (25% anthocyanosides) (PED).

·         Interpretations of Commission E approvals vary slightly: Blumenthal et al. (1998) approve 20–60 g fruit for nonspecific acute diarrhea and local therapy of mild inflammation of the mucous membranes of mouth and throat. Gruenwald et al. (1998) approve the fruits (not leaves) for diarrhea, pharyngosis, and stomatosis. Neither apparently approve for the indications for which I take bilberry, preventing further deterioration of the eyesight (e.g. maculitis, poor night vision, (nyctalopia)). Since bilberry is a healthy food pharmaceutical I’ll take the good old bilberry in spite of its disapproval by these scholastic tomes. It’s even richer in eye-preserving anthocyanosides than our native blueberries.

 

DOSAGES

Internal

·         Fluid extract (1:1) standardised to provide 60–120 mg daily of anthocyanins: 6–12 mL/day taken in three divided doses.

·         Oral dose forms: bilberry extracts providing 240–480 mg of anthocyanins daily.

·         Decoction of dried herb: 5–10 g of crushed, dried fruit in 150 mL of cold water, which is then boiled for up to 10 minutes and strained while hot. For symptomatic treatment of diarrhoea, drink the cold decoction several times daily.

·         Gargle: a 10% decoction of the above preparation.

·         Fresh berries: 165–345 g daily.

External

·         5–10 g crushed dried fruit in 150 mL of cold water, brought to the boil for 10 minutes then strained while hot to make a decoction for local application.

 

DOSAGES

 

BILBERRY LEAF

Preparation: To prepare an infusion, pour boiling water over 1 g finely cut drug (1 teaspoonful = approximately 0.6g) and strain after 10 to 15 minutes. Not to be taken over a long duration.

 

Daily Dosage: The daily dosage of tea is 1 cup 2 to 3 times daily. For an infusion, a single dose is equal to 1 g per cup.

 

BILBERRY FRUIT

Mode of Administration: Tablets, capsules, macerated drug for infusions for internal use and local application.

 

How Supplied:

Most commercially available capsules and tablets are standardized at 25 to 36% anthocyanoside content.

·         Capsule — 40 mg, 60 mg, 80 mg, 125 mg, 160 mg, 310 mg, 400 mg, 500 mg, 1000 mg

·         Tablet — 40 mg

 

Preparation: To prepare an infusion, use 5 to 10 g mashed drug in cold water, bring to a simmer for 10 minutes, then strain (1 teaspoonful = 4 g drug). A 10% decoction is prepared for external use.

 

Daily Dose: 20 to 60 g of unprocessed fruit for internal use. Externally use a 10% infusion. For commercially available tablets and capsules that are standardized to 36% anthocyanosides, the recommended dose is 60 to 160 mg three times daily.

 

 

OVERDOSAGE

BILBERRY LEAF

The signs of poisoning observed in animal experiments (including cachexia, anemia, icterus) appeared only in conjunction with the chronic administration of high dosages and are presumably effects of the tannins.

 

 

PRECAUTIONS AND ADVERSE REACTIONS

 

BILBERRY LEAF

General: No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages. Digestive complaints due to the high tannin content are possible.

Drug Interactions: Bilberry has a platelet aggregation inhibiting effect. There is a possiblility that the herb can interact with other platelet aggregation inhibitors such as aspirin and anticoagulants like warfarin.

 

BILBERRY FRUIT

No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages.

 

CONTRAINDICATIONS, INTERACTIONS, AND SIDE EFFECTS

FRUITS, CLASS 1; LEAF, CLASS 4 (AHP). Leaves can be poisonous consumed over a long period of time (TMA, 1996). Com mission E reports leaf not permitted for therapeutic use; higher doses or prolonged use can produce chronic poisoning; chronic administration of 1.5 g/kg/day is lethal in some animals (AEH). For fruits, none reported (PIP). “Bilberry does not interact with commonly prescribed drugs; no known contraindications in use during pregnancy or lactation; no known side effects with bilberry extracts” (SKY). Berries contain anthocyanosides, said to be helpful in treating eye problems, diarrhea, reducing arterial deposits, and lowering blood sugar in diabetics. Fresh berries may cause diarrhea.

 

SIGNIFICANT INTERACTIONS

Controlled studies are not available, therefore interactions are theoretical and based on evidence of pharmacological activity with uncertain clinical significance.

Anticoagulant and antiplatelet drugs

A theoretical risk exists that high doses (>170 mg anthocyanidins) may increase bleeding risk, however, this remains uncertain as there is inadequate clinical evidence (Stargrove et al 2008).

Iron

Reduced absorption is theoretically possible if taken at the same time because of the tannin content of the herb — separate doses by 2 hours.

 

Hypoglycaemic agents

Additive effects are theoretically possible with leaf preparations — observe patient.

 

CONTRAINDICATIONS AND PRECAUTIONS

High doses (>170 mg anthocyanidins) should be used with caution by people with haemorrhagic disorders.

 

PREGNANCY USE

A study investigating bilberry extract for pregnancy- induced lower extremity oedema reported no adverse effects (Ulbricht & Basch 2005) —likely to be safe when berry is consumed in dietary amounts.

 

CONTRA-INDICATIONS, WARNINGS

Drug Interactions None documented. However, the potential for preparations of bilberry to interact with other medicines administered concurrently, particularly those with similar or opposing effects, should be considered. For example, there is evidence from preclinical studies that V. myrtillus anthocyanins inhibit platelet aggregation and prolong bleeding time, although clinical evidence is limited. It is not known whether or not the use of bilberry preparations concurrently with antiplatelet or anticoagulant agents carries an increased risk of bleeding; concurrent use of bilberry with such agents, and initiation or cessation of bilberry treatments, should be monitored.

Pregnancy and Lactation In an uncontrolled study, V. Myrtillus anthocyanin extract (Tegens) (80 or 160 mg) twice or three times daily for three months was administered to pregnant women with lower limb venous insufficiency and acute-phase haemorrhoids with no apparent adverse effects.(39) However, the safety of bilberry has not been established and, in view of the lack of toxicity data, the use of bilberry during pregnancy and lactation should be avoided.

 

CONTRAINDICATIONS

Pregnancy category is 1; Breastfeeding category is 2A. Bilberry has been used traditionally to help stop breastfeeding (Blumenthal,1998). Avoid large doses in those with clotting/bleeding disorders.

 

SIDE EFFECTS/ADVERSE REACTIONS

GI: Constipation (large consumption of dried fruits)

 

INTERACTIONS

Drug

Anticoagulants (heparin, warfarin), NSAIDs: Bilberry may increase the action of anticoagulants, NSAIDs; use caution if taking concurrently.

 

INTERACTIONS—CONT’D

Antidiabetics: Bilberry may increase hypoglycemia; use caution if taking concurrently.

Antiplatelet agents: Bilberry may cause antiaggregation of platelets; use caution if taking concurrently.

Aspirin: Bilberry may increase the anticoagulation action of aspirin; use caution if taking concurrently.

Insulin: Bilberry leaves may signifi cantly decrease blood glucose levels; monitor carefully.

Iron: Bilberry interferes with iron absorption; avoid concurrent use.

Herb

Hypoglycemic herbs (devil’s claw, fenugreek, garlic, horse chestnut, ginseng [Panax, Siberian]): Bilberry may increase hypoglycemic effect when used with hypoglycemic herbs (Jellin et al, 2008).

Lab Test

Blood glucose: Bilberry may decrease blood glucose.

 

PHARMACOLOGY

Pharmacokinetics

Peak 15 minutes; eliminated via bile. Therapeutic properties vary by harvest area (Burdulis et al, 2007).

EFFECTS

 

EFFECTS: BILBERRY LEAF

The drug is astringent and useful for treating diarrhea due to the catechin tannin content. The drug is antiviral and, in

animal experiments, lipid-lowering. It is thought that the chromium content of the drug is responsible for a possible antidiabetic effect.

 

EFFECTS: BILBERRY FRUIT -

The drug is an astringent and has anti-diarrheal action due to the catechin tannin content which is also responsible for the wound healing effect. Limited data show that the bilberry anthranocyoside is antiexudative, vessel-protective, inhibits platelet aggregation in human blood and has an anti-ulcer effect. Several animal studies have demonstrated that anthocyanosides have a collagen stabilizing effect, and provide protection againts ischemia reperfusion injury (Bertuglia, 1995.)  Increased synthesis of connective tissue is one of the contributing factors that may lead to blindness caused by diabetic retinopathy. Anthocyanides have been shown to slow the synthesis of polymeric collagen in diabetic patients (Boniface, 1996.)

 

CLINICAL STUDIES

One case study involving 20 patients with diabetic retinopathy that were treated with 400 mg of Bilberry extract twice daily demonstrated increased conjunctival capillary resistance in the subjects that were evaluated. The authors of the study concluded that Bilberry provides protection against hemorrhage of the retina (Sevin, 1996.)

 

SIDE-EFFECTS, TOXICITY

A review of clinical trials of V. myrtillus extracts stated that no adverse effects had been observed, even following prolonged treatment.(1) However, most trials involved relatively small numbers of patients and, therefore, would only be able to detect very common acute adverse effects.

The same review summarised the results of an unpublished postmarketing surveillance study which had involved 2295 subjects who had taken Myrtocyan, usually 160 mg twice daily for 1–2 months, for lower limb venous insufficiency, capillary fragility, functional changes in retinal microcirculation or haemorrhoids.

Ninety-four subjects reported side-effects, mainly relating to the skin and gastrointestinal and nervous systems.(1) Long-term consumption of bilberry leaves may lead to toxicity. Chronic administration of doses of 1.5 g/kg per day or more to animals has been reported to be fatal.(G2)

Animal toxicity data indicate that in mice and rats, the LD50 for Myrtocyan is over 2 g/kg and, in dogs, single doses of 3 g/kg produced no adverse effects other than marked darkening of urine and faeces (demonstrating absorption).(1) Oral daily doses to rats and dogs of 125–500 mg/kg and 80–320 mg/kg, respectively, for six months did not induce mortality or toxic effects.(1) Pharmacokinetic studies of V. myrtillus anthocyanins in rats demonstrated that anthocyanins are removed rapidly from the systemic circulation within two hours of oral administration.(26)

 

TOXICITY

Rats administered high doses of up to 400 mg/kg showed no adverse effects (Murray 1995).

 

 

PRACTICE POINTS/PATIENT COUNSELLING

·         Bilberry has antioxidant, anti-inflammatory and astringent actions and has considerable polyphenol content.

·         Bilberry extract is a popular treatment in Europe for preventing and treating retinopathy.

·         It is also used to treat several other ophthalmic conditions such as poor night vision, poor light adaptation, and sensitivity to glare, photophobia, glaucoma, myopia and cataract.

·         Some research also suggests that it is useful in venous insufficiency, peripheral vascular disorders (such as Raynaud’s syndrome) and capillary fragility.

·         Approved by Commission E for the treatment of non-specific, acute diarrhoea and mild inflammatory conditions of the mouth and throat.

·         Preliminary evidence suggests it may reduce serum glucose levels and triglycerides in diabetes and prevent peptic ulcer formation due to NSAIDs or stress; however, clinical research is still required to confirm these effects.

·         In vitro investigation has identified anticarcinogenic activity.

 

 

PATIENTS’ FAQs

What will this herb do for me?

Bilberry is used to relieve the symptoms of mild diarrhoea and improve poor night vision, sensitivity to glare, photophobia, peptic ulcers, varicose veins, venous insufficiency and haemorrhoids when taken internally. It is also used as a mouthwash, gargle or paint for mild inflammation of the mouth or throat, such as gingivitis or pharyngitis.

When will it start to work?

This depends on the indication. Improvements in night vision, photophobia and glare sensitivity have been reported within 2–4 weeks of use in some people whereas preventive effects are likely to require long-term use. In peripheral vascular diseases, 30 days’ treatment may be required before effects are noticed.

Are there any safety issues?

Considered a safe herb overall, bilberry can theoretically reduce blood glucose levels in people with diabetes and so should be used carefully in these patients. At very high doses it may interact with warfarin and antiplatelet drugs.

 

 

CLIENT CONSIDERATIONS

ASSESS

·         Assess whether the client is taking anticoagulants, antidiabetic agents, or antiplatelet agents. Bilberry is known to induce hypoglycemia, anticoagulation, and antiplatelet aggregation (see Interactions).

·         Monitor improvement in vision if using to treat cataracts or glaucoma.

·         Monitor blood glucose if using to treat diabetes mellitus.

 

ADMINISTER

·         Instruct the client to take bilberry PO in the form of tincture, capsules, fl uid extract, or fresh berries.

 

TEACH CLIENT/FAMILY

·         Inform the client that pregnancy category is 1 and breastfeeding category is 2A.

·         Advise the client to notify the herbalist if diarrhea persists for more than 4 days.

·         Advise the client that use of higher-than-recommended doses or use of this herb for extended periods will result in toxicity, and may result in death (leaves).

 

 

PREPARATIONS

 

PROPRIETARY SINGLE-INGREDIENT PREPARATIONS

Australia: Herbal Eye Care Formula. Brazil: Miralis. Germany: Difrarel. Italy: Alcodin; Mirtilene Forte; Tegens. Portugal: Difrarel; Varison. Russia: Mirtilene Forte (Миртилене Форте). Switzerland: Myrtaven.

 

PROPRIETARY MULTI-INGREDIENT PREPARATIONS

Australia: Bilberry Plus Eye Health; Bioglan Pygno-Vite; Bioglan Vision-Eze; Extralife Eye-Care; Extralife Leg-Care; Herbal PMS Formula; Prophthal; Pykno; St Mary's Thistle Plus. Austria: Amersan. Czech Republic: Amersan; Diabetan; Diabeticka Cajova Smes-Megadiabetin; Tormentan; Urcyston  Planta. France: Diacure; Difrarel E; Difrarel; Flebior; Klorane Shampooing Antipelliculaire; Stomargil. Hungary: Difrarel E. Italy: Alvear con Ginseng; Angioton; Api Baby; Bebimix; Biolactine; Capill; Dermilia Flebozin; Evamilk; Memovisus; Mirtilene; Mirtilux; Mirtilux; Neomyrt Plus; Nerex; Pik Gel; Retinovit; Tussol; Ultravisin; Varicofit. Netherlands: Difrarel. Spain: Antomiopic; Mirtilus. UK: I-Sight; Nature's Garden; Se- Power. USA: Bilbery 40mg; Eye Support Formula Herbal Blend; Healthy Eyes; Mental Clarity; My Favorite Multiple Iron-Free; My Favorite Multiple Original; My Favorite Multiple Prime Multi Vitamin; My Favorite Multiple Take One; My Favorite Multiple Take One Iron-Free; Ultimate Antioxidant Formula; Ocusense.

 

EXTRACTS

Flavonoids antiaggregant, antiinflammatory, antioxidant, antispasmodic, preserve capillaries and collagen (PED). Anthocyanosides inhibited barium-induced contraction of isolated thoracic vein and coronary artery smooth muscle, in vitro, possibly by vasodilatory prostaglandin production (PNC). Chromium content (of the leaves) may underlie antidiabetic activity (PHR). Anthocyanins and polyphenols in berries of several Ribes, Rubus, and Vaccinium spp. Have in vitro antiradical activity on chemically generated superoxide radicals. The extracts also inhibit xanthine oxidase. All crude extracts were highly active toward chemically generated superoxide radicals. Ribes nigrum extracts exhibited most activity, being the richest in both anthocyanins and polyphenols. But Ribes rubrum extracts seem to contain more active substances (X1332092). Bilberry extracts (equivalent to 9–72 mg/kg anthocyanins) sometimes exceeded carbenoxolone or cimetidine in antiulcer activity (MAB).

 

 

 

 

 

REFERENCE

 

 

Barnes, J., Anderson, L. A., and Phillipson, J. D. 2007. Herbal Medicines Third Edition. Pharmaceutical Press. Auckland and London.

 

Braun, L and Cohen, M. 2010. Hebs and Natural Supplements An Evidence Based Guide 3R D Edition. Elsevier Australia. Australia.

 

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