Antihyperglycemic effect of Rosa damascena is mediated by PPAR.γ gene expression in animal model of insulin resistance

Abstract

Insulin resistance is a condition in which insulin signaling and action are impaired in insulin sensitive tissues and results in hyperglycemia, hyperlipidemia and type 2 diabetes mellitus. Our previous studies have shown that rosa damascena has antihyperglycemic effects on diabetic and normal rats. Therefore, we conducted a study to evaluate the effect of this medicinal plant on insulin sensitivity in rats. This study was performed on high fructose diet insulin resistant rats and pioglitazone, an insulin sensitizing drug, was used as a positive control. Insulin resistance was developed in animals by high fructose diet within six weeks. Then, rosa damascena extract and pioglitazone were administered by gavage for two weeks and results were compared with two control groups. After treatment period, serum glucose, insulin, adiponectin, triglyceride and cholesterol were assayed in fasting state. Plasma free fatty acid profile was analyzed by GC. Liver PPAR.γ and muscle GLUT.4 gene expressions were assessed by real time PCR and western blotting. Animals were treated with rosa damascena extract showed levels of insulin (42±2.7 pmol/l), adiponectin (5.6±0.17 μg/ml), glucose (129±4.7 mg/dl), and triglyceride (75±9 mg/dl) which were significantly improved as compared with control group insulin (137±34 pmol/l), adiponectin (3.9±0.15 μg/ml), glucose (187±15 mg/dl), and triglycerides (217±18 mg/dl). PPARγ protein level was also significantly increased in Rosa damascene treated group. Our results demonstrated that rosa damascena extract has useful effects on insulin resistant animals and by increasing insulin sensitivity can be considered as a potential agent in control of diabetes.