A. Güder - Department of Medical Services and Techniques, Vocational High School of Health Services, Giresun University, Giresun, Turkey.
M. Gür - Department of Forest Industry Engineering, Faculty of Forestry, Kastamonu University, Kastamonu, Turkey.
M. S. Engin - Faculty of Engineering, Department of Food Engineering, Giresun University, Giresun, Turkey.

Bilberry [Vaccinium myrtillus Linn. (Ericaceae)] fruit (VMF) has been traditionally used for treatment of bladder stones, biliary disorders, scurvy, coughs, and lung tuberculosis. VMF may have some pharmaceutical properties owing to these uses, but in vivo and in vitro studies are limited for clarification of medicinal activity and its antidiabetic and antioxidant properties are not investigated in detail. Anti-amylase, anti-glucosidase, and antioxidant activities of methanol (ME), ethanol (EE), acetone (AE), and water (WE) extracts of VMF were investigated. In addition, some chemical compositions were determined by using spectrophotometric methods. Antidiabetic and antioxidant activities of extracts were studied by using different tests such as α-amylase and α-glucosidase inhibitory, total antioxidant, DPPH scavenging activities according to in vitro methods at different concentrations (۱۰-۲۵۰ μg mL-۱). Compared with the standards, ME, WE, and EE showed strong total antioxidant activities with IC۵۰ (μg/mL) values of ۲۴.۴۶±۰.۳۴, ۲۵.۲۴±۰.۷۸, and ۲۷.۴۸±۰.۶۰, respectively. At the same time, ME (IC۵۰ ۶۱.۳۸±۱.۴۰ μg mL-۱) and EE (IC۵۰ ۶۵.۵۲±۱.۱۹ μg mL-۱) demonstrated very effective inhibitory activity against α-amylase and moderate inhibitory activity against α-glucosidase. All extracts also showed high reducing power, metal chelating activity, superoxide anion, DPPH radical, and H۲O۲ scavenging activities. Important relationships were found between biological activity and chemical composition by statistical analyses. The VMF can be used as an antidiabetic and antioxidant source in medicinal and pharmaceutical areas due to its chemical composition. Anthocyanin contents may influence the anti-amylase inhibition activity more than phenolic and flavonoid contents.

Alpha-amylase, Anthocyanin, Glucosidase inhibition, Flavonoid, Phenol