Dried bilberry (Vaccinium myrtillus L.) extract fractions as antioxidants and cancer cell growth inhibitors

Three antioxidant fractions (Fr1, Fr2 and Fr3) were separated by solid phase extraction from dried bilberry (Vaccinium myrtillus L.) and tested for antioxidant and antiproliferative activity. Vitamin C (1.02 mg/100 g) was identified in Fr1, six flavonoids in Fr2 and eight phenolic acids in Fr3. The most abundant compounds in Fr2 and Fr3 were quercetin (243.3 mg/100 g dried bilberry) and p-coumaric acid (57.87 mg/100 g dried bilberry), respectively. The best free radical scavenging activity on hydroxyl radicals was expressed by Fr3 (EC50⋅OH = 0.117 mg/ml), and on 2,2-diphenyl-1-picrihydrazyl (DPPH) radicals by Fr2 (EC50DPPH⋅ = 0.025 mg/ml). Considering the kinetic behaviour, tested by spectrophotometrical DPPH method, the highest antiradical efficiency (AE = 19.82 ml/mg × min) was demonstrated by Fr2. Fr2 and Fr3 significantly inhibited the growth of cervix epitheloid carcinoma, breast adenocarcinoma and colon adenocarcinoma cell lines, with IC50 ranging from 125.80 to 300.48 μg/ml. Dried bilberry possesses beneficial effects in prevention of cancer and diseases which have been attributed to free radical production.