Effect of Puerariae Lobatae Radix on Expression of Endoplasmic Reticulum Stress Related Proteins GRP78 and ATF6 in T2DM Rats / 中国实验方剂学杂志

ABSTRACT

Objective:To observe the effect of Puerariae Lobatae Radix on type 2 diabetes mellitus (T2DM) rats and related mechanism. Method:Ninety SD rats were divided into normal group, model group, metformin group, Puerariae Lobatae Radix high dose group, Puerariae Lobatae Radix medium dose group and Puerariae Lobatae Radix low dose group, 15 rats in each group. The rats in abnormal group were fed with high-fat and high sugar diet for 4 weeks, and then T2DM model was established by intraperitoneal injection of 40 mg·kg-1 streptozotocin (STZ). Puerariae Lobatae Radix high-dose group was intragastrically administered with 2.1 g·kg-1 of Puerariae Lobatae Radix extract powder, Puerariae Lobatae Radix medium-dose group was intragastrically administered with 1.4 g·kg-1 of Puerariae Lobatae Radix extract powder, Puerariae Lobatae Radix low-dose group was intragastrically administered with 0.7 g·kg-1 of Puerariae Lobatae Radix extract powder, 0.2 g·kg-1 of metformin hydrochloride in metformin group, distilled water once a day in normal group and model group. After 8 weeks, fasting blood glucose (FBG), glycosylated serum protein (GSP), insulin (FINS), triglyceride (TG), cholesterol (TC) were measured, and insulin resistance index （HOMA-IR） was calculated. The expression of tumor necrosis factor -α(TNF-α) was observed by immunohistochemistry. Western blot was used to detect the protein expression of glucose regulatory protein 78 （GRP78）, activated transcription factor 6 （ATF6） in pancreatic tissue. Result:Compared with normal group, the contents of FBG, GSP, TG, TC, FINS, TNF-α in model group were significantly increased (P<0.05), the HOMA-IR was significantly increased (P<0.05), the protein expressions of GRP78 and ATF6 in pancreatic tissue were significantly increased (P<0.05). Compared with model group, the contents of FBG, GSP, TG, TC, FINS and TNF-α in the metformin group and Puerariae Lobatae Radix high, medium and low dose groups were significantly decreased (P<0.05), HOMA-IR decreased significantly (P<0.05), and the expression of GRP78 and ATF6 protein in pancreatic tissue decreased significantly (P<0.05). Conclusion:Puerariae Lobatae Radix can significantly improve insulin resistance in T2DM rats, inhibit the expression of inflammatory factor TNF-α in pancreatic tissue, reduce the protein expression of GRP78 and ATF6 in pancreatic tissue.