Vaccinium myrtillus – Bilberry, European blueberry
Ericaceae – Heather family
The raw material is the ripe bilberry fruit – Myrtilli fructus, harvested in June and July and quickly dried in natural conditions, and the bilberry leaf – Myrtylli folium, harvested from June to August.
Bilberry – appearance and origin:
Bilberry is common in Northern and Central Europe, North America and Asia. In Poland it is found throughout the country, including the mountain region, up to 1800 mamsl. It is a small shrub, 15-30 cm high, thin leaves, singular flowers in leaf angles, reddish-green or greenish-white corolla, blooming from April to June; it forms the undergrowth in pine and spruce woods, in moist and acidic soil.
Bilberry – effects and use:
The medicinal properties are determined by a plethora of active substances. The most important are tannins, mainly derivatives of catechin, epicatechin; anthocyanins, alpha-glucosides, galactosides and arabinosides derived from delphinidin, cyanidin, peonidin, petunidin and malvidin (15 compounds), and two cyanidin- and delphinidin-derived sambubiosides. The berries also contain procyanidin B1 and B4, flavonoids, organic acids and ellagic acid. Discovered in the raw material in 2004, resveratrol is important for the antioxidative effect of bilberry.
The bilberry fruit, thanks to the astringent effect of tannins, is recommended for internal use for diarrhea, especially in children, and for external use for inflammations of the oral and pharyngeal mucosas. Large doses have anthelmintic activity.
Historically, bilberry leaves were used for mild diabetes but lost their reliability due to the possibility of poisoning. Currently, the most widely used groups of substances are anthocyanins with pharmacological properties and related indications. One of the more important is the improvement of the blood flow in veins, especially capillaries, and increasing their seal. One study found that bilberry anthocyanins were twice as effective as rutin in reducing the permeability of vessels, induced with chloroform in rabbits and rats. Administered intravenously to golden hamsters the improved blood floow, especially in the capillaries of skeletal muscles and of the skin.
Bilberry – effects:
For diabetes
It increases the permeability of capillary walls and helps with various circulation disorders observed in diabetics and animals with experimentally induced diabetes. The bilberry fruit can be a good way to prevent complications caused by diabetes. Studies on rats proved the efficacy of the bilberry extract in inhibiting the development of early stages of retinopathy. Another study found that bilberry anthocyanins reduced the permeation of albumins through capillary walls and prevented the damage of interstitial lymphatic vessels in rats with experimental diabetes. Long-term use of an anthocyanin product reversed existing changes in capillary permeability caused by diabetes.
Anti-ulcer
The bilberry extract is also known to inhibit the growth of ulcers of the stomach and duodenum, induced by acetic acid, ethanol, stress and non-steroid anti-inflammatory drugs.
Antioxidant
Many health properties of bilberry anthocyanins are determined by their strong antioxidant activity. It determined the inhibition of numerous oxidation reactions, caused by oxidative stress and leading to degenerative lesions in the dopaminergic pathways, related to pathogenesis. Out of 10 studied fruit extracts, the strongest one was related to antioxidant activity of bilberry anthocyanins, inhibiting the growth of human leukemia HL 60 cells and large intestine cancer HTC 116 cells and inducing apoptosis in these cells. Bilberry can become a valuable medicine in the prevention of diseases caused by oxidative stress.
Vision disorders
Bilberry anthocyanins are currently the most important in treating and preventing vision disorders. Cataract forming and macula degeneration are main causes of worsening visual acuity and blindness in the elderly. The bilberry extract completely prevented lesions in the cornea and macula in animals. There were many studies on the therapeutic efficacy of bilberry anthocyanin extracts, but only one of them, done on 51 patients, concerned its effect on age-related cataract. The bilberry extract used for four months with vitamin E caused the inhibition of lesion growth and even reduced corneal opacity.
Circulation disorders
Many clinical trials confirmed the beneficial effect of various bilberry anthocyanin extracts on peripheral circulation in patients with venous circulation disorders. A flavonoid preparation Colladen, containing extracts of grape seed, bilberry fruit and small cranberry fruit, reduced water retention in women in the premenstrual period and improved the state of the legs, removing the heavy sensation.
Study results point to numerous possibilities to use bilberry anthocyanins in medicine. The ability of these compounds to influence vision in poor lighting. It results from the accelerated regeneration of rhodopsin, also called visual purple, from the enzyme activity in the retina and from the improved microcirculation. Bilberry jam improved visual acuity at night, allowed for quicker adaptation to darkness and quicker regaining of acuity after flashes of light. A 2004 meta-analysis of clinical trials on the influence of bilberry anthocyanins on night vision assessed that studies do not confirm the hypothesis about such an effect, and a significant portion of studies are methodologically questionable. The question of bilberry anthocyanins improving night vision is still unresolved.
PL