Botanic name and Common names

Botanic name- Vaccinium myrtillus.  The other botanic names that are historically used are:   Myrtillus niger Gilib, Myrtillus sylvaticus Drejer, Vaccinium oreophilum Rydb, Vitis-idaea myrtillus (L.) Moench (Ritchie, 1956).

Common Names- Whortleberry, myrtle whortleberry, myrtle blueberry, blueberry, huckleberry, bog berry (Chu, Cheung, Lau & Benzie, 2018).

Botanical description- Vaccinium myrtillus is a member of the Ericaceae family plant grows in the Northern Europe and it is a low growing shrub. However, it is also found in the several parts of Asia and North America. The Plant belongs to the genus Vaccinum along with the other plants like Vaccinium macrocarpon (cranberry) and Vaccinium corymbosum (blueberry). Vaccinium myrtillus grows in the moist coniferous forests, meadows, and heaths and this plant favours the moderately humid ground conditions and moderate shade. American Herbal Products Association has designated Vaccinium myrtillus is a class I herb and this means that the fruits can be safely consumed and when used properly. Also from the plant Vaccinium myrtillus no mutagenic activity and no contraindications from it usage has been reported. The flowers of Vaccinium myrtillus are bell shaped with reddish or pink colour. The leaves are bright green and elliptical arising from the alternating branches. The fruit is purple or blue-black with purple flesh which is small in size (5-9 diameter) and has many seeds (Pfaf.org, 2018).

The plant flowers between the months of April and June and the seeds of the plant ripe between the July and September. Vaccinium myrtillus is a hermaphrodite plant and is pollinated by Lepidoptera, flies and bees. However, the plant id still self-fertile. The plant grows in a loamy and sandy soil with. Vaccinium myrtillus prefer acidic soil and can also grow in acidic soils. It prefers a moist soil but cannot tolerate maritime exposure (Koop-phyto.org, 2018).

Parts used- The parts of the plant Vaccinium myrtillus that are used for consumption and medicinal purposes are the ripe fruits and the leaves. The bark of the root and the root is also used in some cases (Pfaf.org, 2018).  

Anthocyanosides- Anthocyanosides are the compounds that are present in the plants in the form of glycosides (anthocyanins). The important anthocyanins are called the cyaniding glycosides are majority of it is present as a pigment in the fruits. In the Vaccinium species, the anthocyanins are present in the ripe fruits but a majority of the anthocyanins are present in Vaccinium myrtillus fruits. The total anthocyanin content of a ripe fruit is about 300 to 700 grams in Vaccinium myrtillus. Also, it is important to note that the content of the anthocyanins varies depending on the geographical area and this varies from the 19 to 38 mg/g of dry weight fruit. In the concentrated extracts of the bilberry extracts, the total content of anthocyanin is almost about 24 percent. An estimation was made by the European Pharmacopoeia 8.0 which says that a dry extract of Vaccinium myrtillus consists of 32 percent to 39 percent of anthocyanin and it is expressed in the form of cyanide 3-O-glucoside chloride (European Pharmacopoeia, 2018). Studies have shown that Vaccinium myrtillus contains about 14 to 15 anthocyanins. 15 different anthocyanins are found to be in bilberry extract, juice and fruit (Canter & Ernst, 2004).

Structure of cyanide 3-O-glucoside chloride

Botanical Description

Polyphenols- the major polyphenols that are found within the bilberry are the Proanthocyanidins and Flavan-3-ols. The amount of the polyphenols is inversely related with the ripening of the fruit. The other identified polyphenols are the cathechin-dimer B-3, Epicatechin-dimer B-2 (Faria et al., 2005).

Structure of Proanthocyanidins

  Flavonoids- around 14 mg of the flavonoid glycosides are contained within 100g of the fruits. The concentration of the flavonoids decreases as the fruit ripens. The flavonoids that are reported from bilberry are: Kaemferol, chrysoroil, luteolin and apigenin (Riihinen et al., 2008).

Structure of Kaemferol

Alkaloids- an alkaloid called quinolizidine is found, whereas the source of the alkaloids is not confirmed (Slosse & Hootele, 1981).

Structure of quinolizidine

Tannins- the tannins are found in the hydrolyzable and condensed form. The dry fruits contain around 1 percent of the tannin and is expressed as pyrogallol (Moss & Parkinson, 1975).

Structure of pyrogallol

Vitamins- the fresh fruits consist of the nicotinamide, pantothenic acid and vitamin C, B₁ (Prior et al., 1998).

Structure of pantothenic acid

The commercial bilberry products are prepared by standardizing the anthocyanidin at 25 percentages which is equivalent to the 36 percentage of anthocyanins. However, this percentage varies greatly. The pharmaceutical form of the medicines contains about 100 mg of the anthocyanosidic and 5 mg of the beta-carotene. The soft capsules of contain about 70 mg of the Vaccinium myrtillus contains about 70 percent methanol V/V that contains 36 percentage anthocyanosides (Ema.europa.eu, 2018).

Culpeper has described that Vaccinium myrtillus have the qualities of sour, drying, cold and astringent. Vaccinium myrtillus also has a slightly binding effect on the stomach and liver which prevents loathing and vomiting at bay (Culpeper, 2006). The leaves of Vaccinium myrtillus are found to have similar medicinal qualities of that of Urva ursi and the medicinal properties are especially found in the leaves and the bark of the roots. Vaccinium myrtillus is used in the treatment of ulceration of throat and mouth. Also, tea made from the leaves if taken for longer periods help in the treatment of diabetes (Talbott & Hughes, 2007).

The dried bilberry fruit was used for the treatment of diarrhoea and it is also used for the treatment of mild infection in the mucous membranes of the throat and mouth. Traditionally, the dry fruits are also used for the treatment of urinary problems, scurvy, mouth infection, gastrointestinal inflammation, haemorrhoids, dysentery, peripheral vascular disorders, haemorrhoids. The bilberry fruits are traditionally used for the treatment of chronic venous insufficiency, increased fragility conditions of the blood vessels (Madhavi et al., 1998).

Relevant Constituents

Folklore mentions- Anecdotal explanations date back to the world war 2, where the British pilots used to eat the bilberry fruits before the night so as to improve the night visions.

In the Celtic festival of Lughnasa (honouring the god of laugh), Bilberry are the main feature and this influences a vent which known as bilberry Sunday which takes place in the last Sunday of the month of July in parts of Ireland (Botanical.com, 2018).

The fruits and the leaves of Vaccinium myrtillus have therapeutic importance in both the veterinary and human medicine.

• The active ingredients that are present in the leaves have the role of bacteriostatic, astringent and hypoglycaemic. This is recommended in the treatment of rheumatism, gout, blood urea, urinary tract infections, diabetes, diarrhoea.
• The active ingredients that are present in the fruits play a role in the basic treatment of diabetes, sensitizes the photoreceptors, activates the regeneration of the retinal purposes, protects the body from radiation, protects the walls of the blood vessels, helps in cardiovascular regulation, eases the coronary dilators. Urinary antiseptic, intestinal antiseptic, anthelmintic, anti-diarrheal, anti-inflammatory.
• Vaccinium myrtillus leaf and fruit extracts are recommended externally in the treatment of wounds bleeding, eczema, fungal infection, thrush, stomatitis, pharyngitis (Greenlifeuniverse.com, 2018).

• Bilberry contains the anthocyanosides that are the potent antioxidants and this helps in the strengthening the capillary walls of the blood vessels, lowers the cholesterol and stabilizes the collagen tissues like the cartilage, ligaments and tendons. It also increases the concentrations of the retinal pigments that allows eye to tolerate light. The fruit extracts improve the night vision, prevents cataracts and slows down muscular degeneration.
• Oral bilberry extracts are used in the prevention as well as in the treatment of chronic venous insufficiency. This occurs when the valves present in the veins that carry blood back to the heart gets damaged or weakened.
• The dried bilberries are used in the treatment of diarrhoea as it contains tannins and also acts as an astringent for the treatment of gastrointestinal tract.
• Recent researches have shown that the bilberry extract is found to have anti-ulcer activity and it is both curative and preventive. In certain animal experiments the bilberry extracts have shown anti-cancerous properties.
• The bilberry tea in daily consumption have proved to be improving vision by strengthening the blood vessels and retina (Herbwisdom.com, 2018).

 A study was conducted in a rate model to assess the pharmacokinetic profile of the bilberry anthocyanins and also to measure the glucose transporters by using a validated LC-ESI-MS method. This study highlighted the 15 anthocyanins that behave differently with respect to the bioavailability. It is also important to mention that both the sugar moiety and the aglycone significantly affected the PK profile. The difference in the behaviour is noticed and can be explained by assessing the glucose transporters involvement which was previously seen in the CACO- 2 cells. This is also confirmed by computational study and integrated PK study which led to the fact that there is a significant correlation between the molecular recognition of the GLUT2 and sGLT1 with the relative absorption of each of the anthocyanin (Baron et al., 2017).

In vitro experiment- Vasoactive properties: A study was performed on the isolated thoracic vein calf preparations of Vaccinium myrtillus extract and it has been found to reduce the contractions which was induced by 5-HT. The effect was found to be more pronounced when ascorbic acid was added. The relaxing effect got decreased or nullified due to the pre-treatment with lysine acetylsalicylate or indomethacin (Ema.europa.eu, 2018).

In vivo experiments- the effect of the bilberry was studied on the rat model that were deprived of the dietary flavonoids. The wistar rats were fed for 3 weeks with a diet which is devoid of the flavonoids. The capillary fragility was estimated after peritoneal injection, and the data showed that there is big difference between the capillary resistance and the with the bilberry extract in comparison to the controls (Ema.europa.eu, 2018).

 The pharmacological and actions and the efficiency of bilberry are not significantly investigated in the clinical studies. Majority of information is collected through the clinical studies that are derived from the animal model, in vitro tests and all these are based on the knowledge of the key constituents that are present in the herb. The majority of the research undertaken are based on the pharmacology of the drug and is solely focussed on the anthocyanoside and the anthocyanin content of the Vaccinium myrtillus.

• The anthocyanins that are present in the drug may stop blood from clotting during an injury and this can increase the chances of bleeding if the bilberry extracts are taken with the blood thinning medications. This also includes aspirin and fresh fruit form.
• It is not recommended in the diabetic patients because the bilberry extracts are found to reduce the blood sugar level and thus may increase the effects of the diabetic medicine. Also when the bilberry extracts are taken along with the garlic, fenugreek, ginseng, ginger then this might contribute to the hypoglycaemia.
• The long term usage of the leaves is not suitable and can be toxic with the chronic usage of 1.5g/kg/day.
• Long term consumption of the bilberry fruits with a dose equivalent to 180 mg/kg of the anthocyanosides for a period of 6 months produced no toxic effects (Vaccinium myrtillus Bilberry, Whortleberry PFAF Plant Database, 2017).

Parts used

Due to the antiplatelet aggregating properties, very high doses of the bilberry extracts need to be used cautiously with the haemorrhagic disorders (Alternative Medicine Review Volume, 2001).

 The dosage recommended for the bilberry depends on what form of the fruit is being consumed.

• The fresh berries of 55 to 115 grams can be consumed three times daily.
• The dried berries can be consumed daily as it contains only small amount of the flavonoids.
• The bilberry aqueous extracts that are standardized to the 25 percent anthocyanosides can be consumed at the dose of 80 to 160 mg for three times daily. The actual dosage of the anthocyanosides is about 20-40 mg and can be taken for three times per day.  
• 80-160 mg of the standardized capsules that have 25 percent of standardized anthocyanosides can be taken three times daily.
• The leaves are not suggested for the long term use due to the chronic toxicity of 1.5g/kg/day (Anthocyanins, 2017).

References

Alternative Medicine Review Volume 6, Number 5, Page 502. (2001). Vaccinium myrtillus (Bilberry) Monograph. [online] Available at: https://www.altmedrev.com/publications/6/5/500.pdf [Accessed 14 Sep. 2017].

Anthocyanins. (2017). Raysahelian.com. Retrieved 6 November 2017, from https://www.raysahelian.com/anthocyanins.html

Baron, G., Altomare, A., Regazzoni, L., Redaelli, V., Grandi, S., Riva, A., … & Aldini, G. (2017). Pharmacokinetic profile of bilberry anthocyanins in rats and the role of glucose transporters: LC–MS/MS and computational studies. Journal of pharmaceutical and biomedical analysis, 144, 112-121. DOI: https://doi.org/10.1016/j.jpba.2017.04.042Get

Botanical.com. (2018). A Modern Herbal | Bilberry. Retrieved from https://botanical.com/botanical/mgmh/b/bilber37.html#med

Canter, P. H., & Ernst, E. (2004). Anthocyanosides of Vaccinium myrtillus (bilberry) for night vision—a systematic review of placebo-controlled trials. Survey of ophthalmology, 49(1), 38-50. DOI: https://doi.org/10.1016/j.survophthal.2003.10.006

Chu, W., Cheung, S., Lau, R., & Benzie, I. (2018). Bilberry (Vaccinium myrtillus L.). Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK92770/

Culpeper, N. (2006). Culpeper’s complete herbal & English physician. Applewood Books. Retrieved from: https://books.google.co.in/books/about/Culpeper_s_Complete_Herbal_English_Physi.html?id=x0ks6JPrsngC&redir_esc=y

Ema.europa.eu. (2018). Assessment report on Vaccinium myrtillus L., fructus recens and Vaccinium myrtillus L., fructus siccus. Retrieved from https://www.ema.europa.eu/docs/en_GB/document_library/Herbal_-_HMPC_assessment_report/2015/12/WC500198371.pdf

European Pharmacopoeia. (2018). Retrieved from https://online6.edqm.eu/ep800/

Faria, A., Oliveira, J., Neves, P., Gameiro, P., Santos-Buelga, C., de Freitas, V., & Mateus, N. (2005). Antioxidant properties of prepared blueberry (Vaccinium myrtillus) extracts. Journal of Agricultural and Food Chemistry, 53(17), 6896-6902. DOI: https://doi.org/10.1016/j.foodchem.2008.06.066

Greenlifeuniverse.com. (2018). Vaccinium myrtillus (bilberry). Medicinal Action and Uses | Health. Retrieved from https://greenlifeuniverse.com/health/vaccinium-myrtillus-bilberry-medicinal-action-and-uses.html

Herbwisdom.com. (2018). Bilberry Benefits & Information (Vaccinium Myrtillus). Retrieved from https://www.herbwisdom.com/herb-bilberry.html

Koop-phyto.org. (2018). Bilberry (Bilberry, Blueberry, Whortleberry, Huckleberry – Vaccinium myrtillus L.) – Medicinal Plants – Kooperation Phytopharmaka. Retrieved from https://www.koop-phyto.org/en/medicinal-plants/bilberry.php

Madhavi, D. L., Bomser, J., Smith, M. A. L., & Singletary, K. (1998). Isolation of bioactive constituents from Vaccinium myrtillus (bilberry) fruits and cell cultures. Plant Science, 131(1), 95-103. DOI: https://doi.org/10.1016/S0168-9452(97)00241-0

Moss, R., & Parkinson, J. A. (1975). The digestion of bulbils (Polygonum viviparum L.) and berries (Vaccinium myrtillus L. and Empetrum sp.) by captive ptarmigan (Lagopus mutus). British Journal of Nutrition, 33(2), 197-206. DOI: https://doi.org/10.1079/BJN19750024

Pfaf.org. (2018). Vaccinium myrtillus Bilberry, Whortleberry PFAF Plant Database. Retrieved from https://pfaf.org/USER/Plant.aspx?LatinName=Vaccinium+myrtillus

Prior, R. L., Cao, G., Martin, A., Sofic, E., McEwen, J., O’Brien, C., … & Mainland, C. M. (1998). Antioxidant capacity as influenced by total phenolic and anthocyanin content, maturity, and variety of Vaccinium species. Journal of agricultural and food chemistry, 46(7), 2686-2693. DOI: DOI: 10.1021/jf980145d

Riihinen, K., Jaakola, L., Kärenlampi, S., & Hohtola, A. (2008). Organ-specific distribution of phenolic compounds in bilberry (Vaccinium myrtillus) and ‘northblue’blueberry (Vaccinium corymbosum x V. angustifolium). Food chemistry, 110(1), 156-160. DOI: https://doi.org/10.1016/j.foodchem.2008.01.057

Ritchie, J. C. (1956). Vaccinium myrtillus L. The Journal of Ecology, 291-299. Retrieved from: https://www.jstor.org/stable/pdf/2257181.pdf

Slosse, P., & Hootele, C. (1981). Myrtine and epimyrtine, quinolizidine alkaloids from Vaccinium myrtillus. Tetrahedron, 37(24), 4287-4294. DOI: https://doi.org/10.1016/0040-4020(81)85024-7

Talbott, S. M., & Hughes, K. (2007). The health professional’s guide to dietary supplements. Lippincott Williams & Wilkins.

Vaccinium myrtillus Bilberry, Whortleberry PFAF Plant Database. (2017). Pfaf.org. Retrieved 6 November 2017, from https://www.pfaf.org/user/Plant.aspx?LatinName=Vaccinium+myrtillus