ñ-Glucosidase Inhibitory Activity of Common Traditional Medicinal PlantsUsed for Diabetes Mellitus

Inhibition of α-glucosiase and the associated reduction of glucose absorption is an attractive approach for decreasing postprandial hyperglycemia and for the discovery of potent antidiabetic agents. One of the most important sources of potential α-glucosiase inhibitors represents the class of polyphenols. This paper aims to evaluate previous herbal polyphenol-rich extracts plan on the management of diabetes mellitus, to address their α-glucosidase inhibitory activity. Polyphenol-rich extracts from thirteen widely used traditionally anti-diabetic plants in Asia and Mediterranean regions were evaluated for their potential α-glucosidaseinhibitory activity. Among these evaluated plants, 10 were much stronger than that of acarbose standard. Punica granatum manifested the highest inhibitory activity with IC50 at 3.59 ± 0.11 μg/mL, followed by Psidium guajava with IC50 at 8.08 ± 0.10 μg/mL and Cinnamomum zeylanicum with IC50 at 9.87.08 ± 0.14 μg/mLA. A high correlation (r=0.65, p<0.001) was observed between α-glucosidase inhibition and total phenolic content of all plants. Punica granatum, P. guajava, C. zeylanicum and Ziziphus spina-christi had also the highest total phenolic content. Extracts for the above studied plant species may potentially replace acarbose in its current clinical use in improving post-prandial glycaemic control in type 2 diabetics. As a result, these polyphenol-rich extracts potentially offer a complementary approach to develop functional food and potential antidiabetic agents.