Study On Mung Bean Antidiabetes Activity

Mung beans (Vinga radiata L.) belong to phaseoleae of cowpea (Vigna) in a plant cultivated species. It is a miscellaneous grain crop, which can be also used in pharmacy, and its main active components were vitexin, isovitexin and D-chiro-inositol etc.In this study, we investigate mung bean and its spourts. The extract technology of active components in mung bean was established, and the contents of vitexin, isovitexin and D-chiro-inositol were determined. To determine vitexin and isovitexin Alltima C18 column (4.6×250 mm) was used. The mobile phases were acetonitrile (solvent A) and water with 0.2 % acetic acid (solvent B). The elution started with 5 %B, linear gradient to 20 %B in 18min.Then it was 25-90 % B from 18 to 30 min. The flow rate was set at 0.8 mL/min and the injection volume was 10μL. To determine DCI an Alltech Prevail Carbohydrates ES 5μcolumn (4.6×250 mm) was used. The mobile phase was composed of acetonitrile and distilled water (70:30, v/v), the flow rate was set at 1 mL/min, and the elute after the column was sent to an evaporative light scattering detector (ELSD). ELSD conditions were optimized in order to achieve maximum sensitivity, the temperature of the drift tube was set at 95℃, the nebulizing gas flow rate was set at 2.2 L/min.An orthogonal design method was used to optimize the extract technology of the active components in mung bean. The factors were solvent concentration, extraction temperature and time. And the optimized technology was as follows: 75% ethanol of solvent, at 40℃for 120 min. The content of vitexin, isovitexin and D-chiro-inositol in mung bean with a total number of 110 was determined.The antidiabetic effects of Mung bean sprout extracts were investigated in typeⅡdiabetic mice. Male KK-Ay mice and C57BL/6 mice were used in this study. In KK-Ay mice, the blood glucose, plasma C-peptide, glucagon, total cholesterol, triglyceride, and blood urea nitrogen (BUN) levels were significantly higher than those in the C57BL/6 mice (p < 0.001, p < 0.001, p < 0.01, p < 0.001, p < 0.01, and p < 0.01). In addition, KK-Ay mice showed an obvious decrease in insulin immunoreactivity in pancreas as well. Mung bean sprout extracts were orally administrated to KK-Ay mice for 5 weeks. It was found that Mung bean sprout extracts (3 g/kg) lowered blood glucose, plasma C-peptide, glucagon, total cholesterol, triglyceride, and BUN levels and at the same time markedly improved glucose tolerance and increased insulin immunoreactive levels. These results suggest that Mung bean sprout extracts exert an antidiabetic effect in typeⅡdiabetic mice.