Hypoglycemic Effects of Polysaccharide from Dolichos lablab L. via Hypothalamic-Pituitary-Adrenal Axis

Abstract

The present study aimed to investigate hypoglycemic effect of polysaccharide from Dolichos lablab L. (named WHBP) involved in hypothalamic-pituitary-adrenal (HPA) axis in a type II diabetic rat model. In this work, Type II diabetic rat model was established by high fat and high sugar diet combined with the tail vein injection of STZ (30 mg/kg BW), and then these rats were received 1.5 mL of WHBP referring to high (100 mg/kg bw), medium (50 mg/kg bw) and low (25 mg/kg bw) dose of WHBP, respectively. Administration for 4 weeks, the main parameters were examined including body weight, fasting blood glucose (FBG), the serum contents of insulin (INS), corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT). Additionally, the levels of sodium-glucose cotransporter 1 (SGLT1）mRNA was also determined in this work. The results showed that WHBP significantly reduced the levels of FBG and serum INS in type II diabetic rats(P0.05). Furthermore, high-dose WHBP significantly reduced serum CRH, ACTH and CORT contents in type II diabetic rats(P<0.05), suggesting that the activation of HPA axis was attenuated in the atype II diabetic rats by the treatment of WHBP. Moreover, treatment of the WHBP remarkable decreased the levels of SGLT1 mRNA in type II diabetic rats(P<0.05). Collectively, these results suggested that WHBP treatment could improve hypoglycemic effects through via attenuation of insulin resistance, and HPA axis activation and SGLT1 mRNA expression.

Keywords

• white hyacinth bean polysaccharide
• type ⅱ diabetes
• hypoglycemic effects
• hypothalamic-pituitary-adrenal axis