Alpha-Glucosidase Inhibitory Activity in Hexane Extracts of some Plants from Kurdistan Province

Retard absorption of glucose by the inhibition of carbohydrate hydrolyzing enzymes is one of the therapeutic approaches to decrease the postprandial hyperglycemia. Commercial α-glucosidase inhibitors exhibited some serious side effects. So a great deal of attention has been paid to natural products like plants, as a reliable source for bioactive compounds.
The aim of this study was to find new potent inhibitors for Alpha-glucosidase among plant extracts.
Hexane extracts of 60 plants species were screened for their Alpha-glucosidase inhibitory activity at 0.001, 0.01, 0.1 and 1 mg/mL concentration. Alpha-glucosidase activity was determined spectrophotometrically at 405 nm on a Sunrise microplate reader (Tecan- Switzerland) by measuring the quantity of p-nitrophenol released from pNPG. Acarbose, dissolved in buffer, was used as a positive control. The assay was performed in triplicate. The concentration of the extract required to inhibit 50% of Alpha-glucosidase activity under the assay conditions was defined as the IC50value. The results are reported as %I ± SD.
Descurania sophia (L.) Webb & Berth, Fumaria vailantii Loisel, Ferula Haussknechti Wolf & Rech, Haplophyllum acutifolium (DC.) G.Don, Isatis cappadociaca Desv., Eremostachys laevigata Bunge, Silene aucheriana Boiss., exhibited more than 60% alpha-glucosidase inhibitory activity. Among them, Descurania sophia, Fumaria vailantii and Ferula haussknechti exhibited significant alpha glucosidase inhibitory activity with IC50 values of 0.9 µg/ml, 24.55 µg/ml and 2.71 µg/ml, respectively.
Because of its high inhibitory activity and low IC50, hexane extract of Descurania sophia would be interesting for further detailed studies to find and characterize any new inhibitor for Alpha-glucosidase.