Melatonin and L-carnitin improves endothelial disfunction and oxidative stress in Type 2 diabetic rats

Redox Biol. 2016 Aug:8:199-204. doi: 10.1016/j.redox.2015.11.007. Epub 2016 Jan 13.

Abstract

Vascular dysfunction is thought to play a major role in the development of diabetic cardiovascular disease. The roles of endothelial dysfunction, oxidative stress, and dyslipidemia will be considered. Melatonin as well as L-carnitine were shown to possess strong antioxidant properties. Diabetes induced with high fat diet (for 8 weeks) and multipl low doses intraperitoneal injection of STZ (twice, 30mg/kg/d i.p). The diabetic animals were randomly assigned to one of the experimental groups as follows: Control group (C), high fat diet (HFD), STZ-induced diabetic group (HFD+STZ) , HFD+STZ diabetic group received melatonin (10mg/kg/d i.p), HFD+STZ diabetic group received L-carnitine (0.6g/kg/d i.p), and HFD+STZ diabetic group received glibenclamide (5mg/kg/d, oral). The serum fasting blood glucose, insulin, total cholesterol, HDL- cholesterol, LDL-cholesterol, triglyceride and malondialdehyde (MDA) levels were tested. Acetylcholine induced endothelium-dependent relaxation and sodium nitroprusside induced endothelium-independent relaxation were measured in aortas for estimating endothelial function. Also, glutathione peroxidase (GPx), superoxide dismutase (SOD) and nitric oxide (NO) levels activities were determined in rat liver. According to our results melatonin and L-carnitine treatment decreased fasting blood glucose, total cholesterol, and LDL levels. MDA levels significantly decreased with the melatonin treatment whereas SOD levels were not significantly changed between the groups. The results suggest that especially melatonin restores the vascular responses and endothelial dysfunction in diabetes.

Keywords: HFD; L-carnitine; Melatonin; Oxidative stress; Rat; Type 2 diabetes.

MeSH terms

  • Animals
  • Antioxidants / administration & dosage*
  • Carnitine / administration & dosage*
  • Diabetes Mellitus, Experimental / drug therapy*
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Experimental / pathology
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Diabetes Mellitus, Type 2 / metabolism
  • Diabetes Mellitus, Type 2 / pathology
  • Diet, High-Fat
  • Dyslipidemias / blood
  • Dyslipidemias / drug therapy
  • Dyslipidemias / metabolism
  • Dyslipidemias / pathology
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / metabolism
  • Endothelium, Vascular / pathology
  • Glutathione Peroxidase / blood
  • Humans
  • Liver / drug effects
  • Liver / enzymology
  • Melatonin / administration & dosage*
  • Nitric Oxide / blood
  • Oxidative Stress / drug effects
  • Rats
  • Superoxide Dismutase / blood
  • Triglycerides / blood

Substances

  • Antioxidants
  • Triglycerides
  • Nitric Oxide
  • Glutathione Peroxidase
  • Superoxide Dismutase
  • Melatonin
  • Carnitine