Anti-diabetic Properties of Serviceberry(Amelanchier alnifolia)

Diabetes mellitus afflicts an estimated 18.2 million Americans and costs about $132 billion annually. Several plant-based remedies offer cost-effective management of diabetes, but few plant species adapted to North America have been validated for their antidiabetic properties. One such species is serviceberry (Amelanchier alnifolia), found in Browning, MT which has been traditionally used by the American Indians for managing Type 2 diabetes. The objective of this study was to validate and identify potential antidiabetic mechanisms of serviceberry using cell culture techniques. Serviceberry plant samples consisting of leaves, twigs, and leaves with berries were extracted and fractionated. The ethyl acetate and water fractions were tested for activation of 2-deoxyglucose uptake, dipeptidyl peptidase-4 (DPP-4) inhibitory activity, and alpha-glucosidase inhibition. In L6GLUT4myc skeletal muscle cells, insulin (100 nM) induced a 1.5–2.0 fold activation of 2-deoxyglucose uptake. Two of the water fractions demonstrated modest activation of 2-deoxyglucose uptake. The ethyl acetate and water fractions were devoid of DPP-4 inhibitory activity. Water fractions from leaves and twigs demonstrated inhibition of alpha-glucosidase activity, similar to that of the positive control, acarbose. The activity was enhanced 2–7 fold, after chromatographic purification. Water fractions also demonstrated a dose-dependent suppression of dexamethasone-induced gluconeogenic gene expression in H4IIE rat hepatoma cells. These findings suggest that the alpha-glucosidase inhibitory activity, which slows down the digestion of complex carbohydrates, and the suppression of hepatic gluconeogenesis, may be potential mechanisms that can lead to lowering of blood glucose levels and conferring an anti-diabetic effect of serviceberry. Acknowledgements: Funding from the USDA/CSREES Tribal Colleges Research Grants Program is gratefully acknowledged.