The anti-diabetic effects of Kocat-D1 on streptozotocin-induced diabetic rats

This study was conducted to investigate the anti-diabetic activity of Kocat-D1, which is widely used in traditional medicine to treat diabetes in Shandong, China. Sprague Dawley rats (8 weeks of age) were separated into 4 groups: a normal control, streptozotocin (STZ)-induced diabetic rat group (DM control), Kocat-D1-1 (diabetic rat treated with 0.25 g/kg/day hot water extract), and Kocat-D1-2 (diabetic rat treated with 1 g/kg/day hot water extract). After eight weeks of treatment, the fasting blood glucose levels of the Kocat-D1-1 (334.3±32.9 mg/dL) and Kocat-D1-2 group (259.5±35.0 mg/dL) were significantly lower when compared to the DM control group (451±42.6 mg/dL). Furthermore, the levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), albumin and high-density lipoprotein (HDL) cholesterol in the serum of the Kocat-D1-2 group were significantly normalized when compared to the DM control group. However, significant differences were not observed between the Kocat-D1-1 group and the DM control group. Histochemical staining of the liver of the Kocat-D1-2 group revealed no fat accumulation. The insulin level was significantly upregulated in the Kocat-D1-2 group (0.13±0.02 ng/mL) when compared to the DM control group (0.05±0.04 ng/mL). The relative volume of β-cells in the pancreas of the Kocat-D1-2 group (49.4±4.2%) also increased significantly when compared to the DM control group (12.9±7.9%). These results suggest that Kocat-D1 exerts an anti-hyperglycemic effect through the enhancement of insulin secretion.