Effects of platycodins on liver complications of type 2 diabetes

The aim of the current study was to investigate the therapeutic effects and mechanism of platycodin in liver complications of type 2 diabetes. All rats were randomly divided into two groups: The control group (normal diet) and the model group (a high‑fat and high‑sugar diet). The model group was injected with 2% streptozocin (25 mg/kg body weight) through the tail vein following 4 weeks of dieting. After a total of 8 weeks of dieting, fasting blood glucose (FBG) and liver function were examined. The high‑fat and high‑sugar diet was continued in the successful model rats, which were randomly divided into four groups and treated with the following doses of platycodins: The untreated, and 50, 100 and 200 mg/kg body weight/day groups. Platycodins treatment lasted for 12 weeks. Platycodins treatment at a dose of 200 mg/kg body weight/day reduced the FBG, glutamate pyruvate transaminase (GPT), glutamic oxalacetic transaminase, triglycerides, total cholesterol (TC), low‑density lipoprotein (LDL) and liver index levels compared with the untreated group (P<0.05), while the high‑density lipoprotein levels increased (P<0.05). Furthermore, FBG, GPT, TC and LDL levels were returned to the normal level. This dose also increased the expression of BMP‑9 mRNA and BMP‑9 protein, and reduced the expression of Smad‑4 mRNA and Smad‑4 protein. These findings indicate that platycodins can rectify disorders of blood glucose and lipid metabolism, improve liver index and protect liver function in liver complications of type 2 diabetes. The current study suggests that this therapeutic effect is mediated through the BMP‑9/Smad‑4 pathway.