A member of the Ericaceae family, bilberry (Vaccinium myrtillus) is native to northern Europe and North America, and its fruit is known to contain myriad polyphenols that display potent antioxidant and anti-inflammatory activity.1,2 Also known as European blueberry or whortleberry, this perennial deciduous shrub is also one of the richest sources of the polyphenolic pigments anthocyanins.3-5 Indeed, anthocyanins impart the blue/black color to bilberries and other berries and are thought to be the primary bioactive constituents of berries associated with numerous health benefits.3,6 They are also known to confer anti-allergic, anticancer, and wound healing activity.4 Overall, bilberry has also been reported to exert anti-inflammatory, lipid-lowering, and antimicrobial activity.3 In this column, the focus will be on the chemical constituents and properties of V. myrtillus that indicate potential or applicability for skin care.
Dr. Leslie S. Baumann
Active ingredients of bilberry
Bilberry seed oil contains unsaturated fatty acids such as linoleic acid and alpha-linolenic acid, which exhibit anti-inflammatory activity and contribute to the suppression of tyrosinase. For instance, Ando et al. showed, in 1998, that linoleic and alpha-linolenic acids lighten UV-induced skin hyperpigmentation. Their in vitro experiments using cultured murine melanoma cells and in vivo study of the topical application of either acid to the UV-induced hyperpigmented dorsal skin of guinea pigs revealed pigment-lightening effects that they partly ascribed to inhibited melanin synthesis by active melanocytes and accelerated desquamation of epidermal melanin pigment.7
Anneli Salo/CC BY-SA 3.0
A 2009 comparative study of the anthocyanin composition as well as antimicrobial and antioxidant activities delivered by bilberry and blueberry fruits and their skins by Burdulis et al. revealed robust functions in both fruits. Cyanidin was found to be an active anthocyanidin in bilberry. Cultivars of both fruits demonstrated antimicrobial and antioxidant activity, with bilberry fruit skin demonstrating potent antiradical activity.8
The anthocyanins of V. myrtillus are reputed to impart protection against cardiovascular disorders, age-induced oxidative stress, inflammatory responses, and various degenerative conditions, as well ameliorate neuronal and cognitive brain functions and ocular health.6
In 2012, Bornsek et al. demonstrated that bilberry (and blueberry) anthocyanins function as potent intracellular antioxidants, which may account for their noted health benefits despite relatively low bioavailability.9
Six years later, a chemical composition study of wild bilberry found in Montenegro, Brasanac-Vukanovic et al. determined that chlorogenic acid was the most prevalent phenolic constituent, followed by protocatechuic acid, with resveratrol, isoquercetin, quercetin, and hyperoside also found to be abundant. In vitro assays indicated significant antioxidant activity exhibited by these compounds.10
Activity against allergic contact dermatitis
Yamaura et al. used a mouse model, in 2011, to determine that the anthocyanins from a bilberry extract attenuated various symptoms of chronic allergic contact dermatitis, particularly alleviating pruritus.8 A year later, Yamaura et al. used a BALB/c mouse model of allergic contact dermatitis to compare the antipruritic effect of anthocyanin-rich quality-controlled bilberry extract and anthocyanidin-rich degraded extract. The investigators found that anthocyanins, but not anthocyanidins, derived from bilberry exert an antipruritic effect, likely through their inhibitory action on mast cell degranulation. They concluded that anthocyanin-rich bilberry extract could act as an effective oral supplement to treat pruritic symptoms of skin disorders such as chronic allergic contact dermatitis and atopic dermatitis.11