Hypoglycemic effect of glycyrrhizic acid, a natural non-carbohydrate sweetener, on streptozotocin-induced diabetic mice

Abstract

In this paper, glycyrrhizic acid (GZA) was extracted from the stem of licorice by enzymatic hydrolysis, separated and purified by silica gel column chromatography, its purity was determined by high performance liquid chromatography (HPLC), and the structure was identified by Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The hypoglycemic activity of GZA was measured by α-glucosidase inhibition in vitro and the establishment of a T2DM diabetic mouse model in vivo. The experimental results showed that the extraction rate and purity of GZA were 92.4% and 93.53%, respectively, and the IR spectrum and NMR spectrum were consistent with the standard and literature, respectively. The IC₅₀ value of GZA for α-glucosidase inhibition was 1.88 mmol L^-1, which was close to the positive control (acarbose). In addition, GZA could reduce the fasting blood glucose of T2DM mice by increasing insulin sensitivity, increasing glucose tolerance, significantly decreasing serum triglyceride (TG), total cholesterol (TC), and low density lipoprotein cholesterol (LDL-C) contents, and increasing high density lipoprotein cholesterol (HDL-C) content. At the same time, it could also repair damaged organs to some extent. Therefore, GZA has broad application prospects in the treatment of T2DM.