Huang B, et al. Nutr Res Pract. 2015 Feb;9(1):22-29. https://doi.org/10.4162/nrp.2015.9.1.22

Zhang XH, et al. Nutr Res Pract. 2012 Aug;6(4):286-293. http://dx.doi.org/10.4162/nrp.2012.6.4.286

To evaluate the antihyperglycemic effect of a standardized extract of the leaves of Morus alba (SEMA), the present study was designed to investigate the α‐glucosidase inhibitory effect and acute single oral toxicity as well as evaluate blood glucose reduction in animals and in patients with impaired glucose tolerance in a randomized double‐blind clinical trial. SEMA was found to inhibit α‐glucosidase at a fourfold higher level than the positive control (acarbose), in a concentration‐dependent manner. Moreover, blood glucose concentration was suppressed by SEMA in vivo. Clinical signs and weight changes were observed when conducting an evaluation of the acute toxicity of SEMA through a single‐time administration, with clinical observation conducted more than once each day. After administration of the SEMA, observation was for 14 days; all of the animals did not die and did not show any abnormal symptoms. In addition, the inhibitory effects of rice coated with SEMA were evaluated in a group of impaired glucose tolerance patients on postprandial glucose and a group of normal persons, and results showed that SEMA had a clear inhibitory effect on postprandial hyperglycemia in both groups. Overall, SEMA showed excellent potential in the present study as a material for improving postprandial hyperglycemia.

In the present study, we investigate anti-diabetic effect of pectinase-processed ginseng radix (GINST) in high fat diet-fed ICR mice. The ICR mice were divided into three groups: regular diet group, high fat diet control group (HFD), and GINST-treated group. To induce hyperglycemia, mice were fed a high fat diet for 10 weeks, and mice were administered with 300 mg/ kg of GINST once a day for 5 weeks. Oral glucose tolerance test revealed that GINST improved glucose tolerance after glucose challenge. Compared to the HFD control group, fasting blood glucose and insulin levels were decreased by 57.8% (p<0.05) and 30.9% (p<0.01) in GINST-treated group, respectively. With decreased plasma glucose and insulin levels, the insulin resistance index of the GINST-treated group was reduced by 68.1% (p<0.01) compared to the HFD control group. Pancreas of GINST-treated mice preserved a morphological integrity of islets and consequently having more insulin contents. In addition, GINST up-regulated the levels of phosphorylated AMP-activated protein kinase (AMPK) and its target molecule, glucose transporter 4 (GLUT4) protein expression in the skeletal muscle. Our results suggest that GINST ameliorates a hyperglycemia through activation of AMPK/ GLUT4 signaling pathway, and has a therapeutic potential for type 2 diabetes.