Effect of Extracts of Bilberries (Vaccinium myrtillus L.) on Amyloglucosidase and α-Glucosidase Activity

Open access


Background: Vaccinium myrtillus L. is a species belonging to the genus Vaccinium of the family Ericaceae. Bilberries have drawn attention due to the multiple benefits for the human health, including antioxidant, anti-inflammatory, anticancer, anti-neurodegenerative, and cardioprotective effects. Recently, bilberries were shown to inhibit the activity of carbohydrate-hydrolysing enzymes that can help reduce the intensity of the metabolic syndrome and prevent type 2 diabetes.

Aim: In this study, we investigated the α-glucosidase and amyloglucosidase inhibitory activities of polyphenol-rich extracts from fruit of Vaccinium myrtillus L. from different regions in Bulgaria.

Materials and methods: The total phenolic content was determined spectrophotometrically using the Folin-Ciocalteu method. With HPLC analysis, phenolic acid composition of extracts was assessed. Enzymatic inhibitory activities were determined according to the methodology by Borooah et al. (1961), and Dewi et al. (2007). Amyloglucosidase assay and α-glucosidase assay were used to measure the inhibition potential of bilberries’ extracts.

Results: Phenolic compound content ranged from 1299.60 mg to 510.88 mg GAE/100 g for organic extracts and from 453.63 mg to 290.83 mg GAE/100 g for aqueous extracts. Based on qualitative HPLC analyses, gallic acid and chlorogenic acid were found to be among the major phenolic acids present in bilberries. Methanol and aqueous extracts there were found to be effective inhibitors of α-glucosidase with an IC50 value of 20 μg GAE/ml and 55 μg GAE/ml, respectively.

Conclusion: The inhibitory activity of bilberries’ extracts towards α-glucosidase offers the patients with type 2 diabetes the opportunity to manage their own glycaemic levels with a diet.

1. Giacalone M, Di Sacco F, Traupe I, et al. Antioxidant and neuroprotective properties of blueberry polyphenols:A critical review. Nutr Neurosci 2011;14(3):119-25.

2. Torri E, Lemos M, Caliari V, et al. Anti-inflammatory and antinociceptive properties of blueberry extract (Vaccinium corymbosum). J Pharm Pharmacol 2007;59(4):591-6.

3. McDougall GJ, Stewart D. The inhibitory effects of berry polyphenols on digestive enzymes. Biofactors 2005;23(4):189-95.

4. Tsuda T, Horio F, Uchida K, et al. Dietary cyanidin 3-O-beta-d-glucoside-rich purple corn color prevents obesity and ameliorates hyperglycemia in mice. J Nutr 2003;133(7):2125-30.

5. Du Q, Jerz G, Winterhalter P. Isolation of two anthocyanin sambubiosides from bilberry (Vaccinium myrtillus) by high-speed counter-current chromatography. J Chromatogr A 2004;1045 (1-2):59-63.

6. Wang H, Cao G, Prior RL. Oxygen radical absorbing capacity of anthocyanins. J Agric Food Chem 1997;45(2):304-9.

7. Kader F, Rovel B, Girardin M, et al. Fractionation and identification of the phenolic compounds of high-bush blueberries (Vaccinium corymbosum L.). Food Chem 1996;55 (1):35-40.

8. Moze S, Polak T, Gasperlin L, et al. Phenolics in Slovenian bilberries (Vaccinium myrtillus L.) and blueberries (Vaccinium corymbosum L.). J Agric Food Chem 2011;59(13):6998-7004.

9. Häkkinena S, Törrönena R. Content of flavonols and selected phenolic acids in strawberries and Vaccinium species: influence of cultivar, cultivation site and technique. Food Res Int 2000;33(6):517-24.

10. Meskin MS, Bidlack WR, Davies AJ, et al. Phytochemicals in nutrition and health. CRC PRESS Boca Raton London New York Washington; 2002.

11. Giovanelli G, Buratti S. Comparison of polyphenolic composition and antioxidant activity of wild Italian blueberries and some cultivated varieties. Food Chem 2009;112(4):903-8.

12. Singleton VL, Rossi JAJ. Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. Am J Enol Vitic1965;16:144-58.

13. Borooah J, Leaback DH, Walker PG. Studies on glucosaminidase. 2. Substrates for N-acetyl-β-glucosaminidase. Biochem J 1961;78(1):106-10.

14. Dewi RT, Iskandar YM, Hanafi M, et al. Inhibitory effect of koji Asspergilus terreus on α-glucosidase activity and postprandial hyperglycemia. Pak J Biol Sci 2007;10(8):3131-35.

15. Hall CA, Cuppet SL. Structure-activities of natural antioxidants. In: Aruoma OI, Cuppett SL, eds. Antioxidant Methodology: in Vivo and in Vitro Concepts. Champaign, IL USA:AOCS Press;1997:141-72.

16. Adeniran HA, Abiose SH, Ogunsua AO. Production of fungal β-amylase and amyloglucosidase on some Nigerian agricultural residues. Food Bioprocess Tech 2010;3(5):693-8.

17. Chethan S, Sreerama Y, Malleshi N. Mode of inhibition of finger millet malt amylases by the Millet Phenolics. Food Chem 2008;111(1):187-91.

18. Kunyanga C, Imungi J, Okoth M, et al. Total phenolic content, antioxidant and antidiabetic properties of methanolic extract of raw and traditionally processed Kenyan indigenous food ingredients. LWT-Food Sci Technol 2012;45(2):269-76.

19. Boath A, Stewart D, McDougall G. Berry components inhibit alpha-glucosidase in vitro: synergies between acarbose and polyphenols from black currant and rowanberry. Food Chem 2012;135(3):929-36.

20. Akkarachiyasit S, Charoenlertkul P, Yibchok-anun S, et al. Inhibitory activities of cyanidin and its glycosides and synergistic effect with acarbose against intestinal a-glucosidase and pancreatic a-amylase. Int J Mol Sci 2010;11(9):3387-96.

21. McDougall GJ, Kulkarni NN, Stewart D. Current developments on the inhibitory effects of berry polyphenols on digestive enzymes. Biofactors 2008;34(1):73-80.

Folia Medica

The Journal of Medical University-Plovdiv

Journal Information

CiteScore 2018: 0.587

SCImago Journal Rank (SJR) 2018: 0.311


All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 280 222 18
PDF Downloads 190 174 15