Protective effect of compound K on diabetic rats.

Purpose: Compound K (CK), the metabolic product of protopanaxadiol saponin in vivo, has many pharmacological activities. In this study, we discuss the preparation of CK, and its protective effect on kidneys of diabetic rats. CK was prepared from ginsenoside Rbt after transformation by 3-glucosidase, separation and purification by silica gel column chromatography. In the present study, we established a rat model of diabetes mellitus using high-fat diet and streptozotocin (STZ). After seven weeks of treatment, the levels of fasting blood glucose (FBG), total cholesterol (TC), total glycerin (TG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), blood urea nitrogen (BUN), uric acid (UA), serum creatinine (Scr), malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-PX) were evaluated in normal and diabetic rats. Also, renal pathomorphism changes were observed by HE stain, and TGF-ß1 protein expression in the renal tissue was measured by Western blot. The yield of CK was 14.55 mg/mL, which was higher than that of other methods. After seven weeks, CK could decrease FBG, TC, TG, LDL-C, BUN, UA, Scr and MDA of diabetic rats, while CK also enhanced HDL-C and GSH, SOD and GSH-PX. Additionally, CK improved the pathological changes and decreased TGF-ß1 protein expression in the renal tissue. CK improved the pathological changes in the renal tissue, enhanced the antioxidant capacity, reduced the damage of TGF-ß1 to renal tissue, and protected the diabetic rats.

Protective effect of Schisandrae chinensis oil on pancreatic ß-cells in diabetic rats.

Islet cell dysfunction in type 2 diabetes is primarily attributed to increased apoptosis of pancreatic ß-Cells. The aim of the present study was to investigate the effects of Schisandrae chinensis oil on pancreatic ß-Cells in type 2 diabetes mellitus rats and the associated molecular mechanisms of action. Wistar rats were randomly divided into diabetic rats and control rats, diabetic rats treated with Schisandrae chinensis oil (1 mg/kg), and control rats treated with Schisandrae chinensis oil. The serum fasting blood glucose, insulin, total cholesterol, and triglyceride levels along with MDA content, SOD and CAT activities in pancreatic tissues were measured. TUNEL was used to observe the apoptosis of rat pancreatic cells. Western blot was used to determine specific protein expression. The results showed that the oil significantly decreased fasting blood glucose, total cholesterol, triglyceride levels as well as the pancreatic MDA, but increased SOD and CAT activities. The protein expression of Bcl-2, PDX-1, GLUT-2, and GCK but not caspase 3 was significantly enhanced in the oil-treated rats compared with diabetic rats. However, Bax content was not significantly different between the control and DM groups. Schisandra chinensis oil improves pancreatic ß-cell function by enhancing antioxidant potential of the pancreas, upregulating the expression of anti-apoptotic genes, increasing expression of glucose metabolism, and delaying islet cell apoptosis.