The extraction, identification and quantification of hypoglycemic active ingredients from stinging nettle (Urtica angustifolia)

Urtica angustifolia is a traditional medicinal material which has hypoglycemic function. The objectives of this study were to isolate and identify hypoglycemic active ingredients from it. Three groups of mice were gavaged with the decoction of Urtica root, stem and leaf for 14 days at a dose of 20 mg/(kg·d). Area under the curve (AUC) values were 24.62±5.24, 24.33±4.66 and 25.51±4.25, respectively. The AUC in leaf decoction group was significantly lower than the other two groups (P < 0.05), which indicated the leaf extracts did have significant hypoglycemic action. Four kinds of extractions were obtained from leaves and fed to mice. AUC values were 33.44±3.58, 34.24±3.64, 30.44±2.57 and 9.93±1.98, respectively. AUC in group U3 (P < 0.05) and U4 (P < 0.01) were significantly lower than in the group of U1 and U2, which indicated that extraction U3 and U4 obviously decreased the blood sugar. Also, U3 was flavonoid and U4 was daucosterol, which was identified by thin-layer chromatography test, IR and ESI-MS spectral analysis.Key words: Urtica angustifolia, active component, glucose tolerance test, hypoglycemic