Anti-diabetic and anti-dyslipidemic effects of Naringin.

Abstract

The incidence of diabetes is expected to dramatically increase over the next decade. Dyslipidemia is the greatest risk factor of coronary heart diseases in patients with diabetes. Antidiabetic and anti-dyslipidemic effects of naringin were investigated in type 1 diabetes. Male Sprague-Dawley rats (n = 7) were treated daily with 3.0 ml/kg body weight (BW) of water (group 1), naringin (50 mg/kg BW) (groups 2, 4 and 7, respectively), regular insulin (4 U/kg BW, subcutaneously, twice daily) (group 3 and 7), and simvastatin (20 mg/kg BW) in group 6. On treatment day 45, halothane overdose was used to sacrifice the animals and blood samples were collected via cardiac puncture for plasma insulin and lipid profile analysis. Rat livers were excised, rinsed in normal saline and stored at -80⁰C for glycogen content analysis. Group 3, 4, 5, 6 and 7 exhibited weight loss, polydipsia and hyperglycemia after injection with 60 mg/kg body weight of streptozotocin. Naringin with or without insulin significantly prevented weight loss in diabetic animals compared to non-treated diabetic animals. Insulin with/without naringin, but not naringin, significantly lowered fasting blood glucose levels in diabetic rats. Naringin with/without insulin significantly improved hepatic glycogen content compared to nontreated diabetic rats. Naringin with/without insulin significantly increased the plasma insulin levels in diabetic animals compared to non-treated diabetic animals. Plasma total cholesterol, triglycerides, very low density lipoprotein, low density lipoprotein cholesterol concentrations were significantly higher in non-treated diabetic rats compared to non-diabetic controls. High density lipoprotein cholesterol was significantly higher in non-treated diabetic rats compared to non-diabetic control. Naringin with/without insulin improved lipid profile in diabetic animals, whereas simvastatin decreased only total cholesterol and triglycerides compared to non-treated diabetic animals. Naringin with/without insulin significantly decreased coronary risk index in diabetic animals compared to non-treated diabetic animals. Atherogenic index was significantly decreased by insulin or naringin with/without insulin in diabetic rats compared to non-treated rats. Naringin is not hypoglycemic but improves coronary risk index and atherogenic index in type 1 diabetes. However, naringin with insulin showed synergistic effects. This study was conducted to investigate the effect of naringin on blood glucose regulation dyslipidemia in type 1 diabetes. The results showed that naringin is not hypoglycemic, however, it improved fasting plasma insulin and hepatic glycogen. Naringin also showed anti-dyslipidemic effects by decreasing the antherogenic lipids and increasing the high density lipoprotein cholesterol. The findings suggests that naringin can be used as a dietary supplement to ameliorate diabetic dyslipidemia.