Effect and mechanism of Rosa roxburghii polysaccharide on improving insulin resistance in obese rats

Abstract

Objective: This study aimed to develop R. roxburghii as functional food in medicine and health care products. Methods: High-fat dial-induced insulin resistance rat model was established. There were normal control group, the model group, the positive control group, and the low and high dose group of R. roxburghii polysaccharide (100 mg/kg and 200 mg/kg). The body weight was recorded before and after the experiment. The serum oxidative stress indexes (SOD, MDA), lipid metabolism indexes (TG, TC), fasting blood glucose (FBG) and fasting insulin (FINS) levels, as well as the mRNA and protein expressions of PI3K and GLUT4 mRNA in skeletal muscle were detected. Results: Compared with the model group, the body weight, serum MDA, TG, TC, FBG, FINS, HOMA-IR were decreased (P＜0.01), and the SOD activity and the mRNA and protein expression levels of PI3K and GLUT4 were increased after polysaccharide intervention in IR rats after R. roxburghii polysaccharide intervention (P＜0.05). Conclusion: R. roxburghii polysaccharide (PRR-3) has antioxidant effect, which can reduce the weight of insulin-resistant rats, regulate glucose and lipid metabolism, and improve obesity insulin resistance. There is a dose-effect relationship, which may be achieved by up-regulating the expression of PI3K and GLUT4 proteins in the PI3K/AKT/GLUT4 signaling pathway and enhancing GLUT4 transport.

Keywords

• rosa roxburghii polysaccharide
• obesity
• oxidative stress
• insulin resistance
• phosphatidylinositol 3 kinase (pi3k)
• glucose transporter 4(glut4)