Anti-diabetic effects of sprouts in high-fat diet and streptozotocin-induced type II diabetes mellitus mice

Sprout vegetables containing various types of polyphenols and flavonoids, are known to have anti-inflammatory, antioxidant, cholesterol-lowering, and anti-obesity activities. However, there have been few reports on the anti-diabetic efficacy of sprout vegetables. Here, we investigated the anti-diabetic effects of sprout extract obtained from buckwheat, beet, rape, broccoli, kohlrabi, red young radish, and dachai, in high fat diet (HFD) and streptozotocin (STZ)-induced type Ⅱ diabetes mellitus mice. The mice were fed a HFD (60% calories as fat) for 8 weeks prior to intraperitoneal injection with STZ (75 mg/kg). The diabetic mice were divided into four groups: standard diet (STD, 10% calories fat), HFD, HFD with sprout extract (SPE) and HFD with metformin (MET). After 4 weeks, body weight gain was much lower in both SPE and MET groups than in HFD group. In contrast, there was no difference experiment groups regarding food intake ratio. The level of fasting blood glucose was significantly lower in the SPE and MET groups compared to the HFD group. Oral glucose tolerance and insulin tolerance in the SPE and MET groups were significantly ameliorated in comparison to the HFD group. The concentrations of serum total cholesterol, triglycerides, and LDL cholesterol in the SPE and MET groups were remarkably reduced in comparison to the HFD group, and HDL cholesterol concentration was higher in the SPE and MET groups than in the HFD group. Glutamate oxaloacetate transaminase and glutamate pyruvate transaminase levels were between SPE and HFD groups. The serum insulin and leptin concentrations were significantly reduced in both the SPE and MET groups compared to the HFD group. Therefore, these results indicate that sprout extract could improve insulin resistance and attenuate blood glucose level in HFD/STZ-induced type Ⅱ diabetes mellitus mice. We conclude that this study may provide positive insights into sprout extract as a functional food ingredient for treatment of type Ⅱ diabetes mellitus.