Hypoglycemic activities of commonly-used traditional Chinese herbs.

The α-amylase and α-glucosidase inhibition activity of 92 Traditional Chinese Medicinal (TCM) herbs, which are permitted to be used as food ingredients, were evaluated using the high throughput assay developed in our laboratory. Among these herbs, twenty-seven of them possessed significant α-amylase inhibition activities ranging from 2.4 to 349.2 µmol AE/g (AE = acarbose equivalent) with inhibition concentrations at 50% inhibition (IC50) from 16.0 to 2342.2 µg/mL, respectively. In addition, they showed α-glucosidase inhibition activities ranging from 0.5 to 31.6 µmolAE/g (IC50 from 49.0 to 3385.5 µg/mL). The extracts of Rhizoma fagopyri dibotryis (Jinqiáomài), Rosa rugosa (Méiguihua), Caulis polygoni multiflori (Shǒuwuténg), Fructus amomi (Sharén), Rhizoma alpiniae officinarum (Gaoliángjiang), Folium ginkgo (Yínxìngyè) and Cortex cinnamomi (Ròuguì) showed the better inhibitory activities against both α-amylase and α-glucosidase. Our results illustrated that these food grade herbs are potent natural hypoglycemic agents and can be used as active ingredients for low glycemic index food production or TCM herbal formulations for controlling hyperglycemia.