title: Myrtenal alleviates hyperglycaemia, hyperlipidaemia and improves pancreatic insulin level in STZ-induced diabetic rats.
abstract: BACKGROUND
  Myrtenal is monoterpene a constituent of essential oils found mainly in herbs such as mint, pepper, cumin, etc. It exerts admirable pharmacological activities against many diseases including diabetes. Hyperlipidaemia is a secondary complication of diabetes and also a major risk factor for cardiovascular diseases.
  
  
  OBJECTIVE
  The present study investigated the possible antihyperlipidaemic efficacy of myrtenal on plasma glucose, pancreatic insulin, plasma and tissue lipid levels in streptozotocin (STZ) induced diabetic rats.
  
  
  METHODS
  Diabetes was induced in male Wistar rats by a single intraperitoneal injection of STZ (40 mg/kg b.w.). Myrtenal (80 mg/kg) was administered orally to diabetic rats for a period of 28 d. Plasma glucose, pancreatic insulin, TC, TGs, FFAs, PLs, LDL-C, HDL-C, VLDL, atherogenic index, (HMG-CoA) reductase, LPL, LCAT and liver histology were analyzed.
  
  
  RESULTS
  Diabetic rats showed significantly (p < 0.05) increased plasma glucose (273.18 mg/dL), total cholesterol (142 mg/dL), triglycerides (126 mg/dL), free fatty acids (118 mg/dL), phospholipids (153 mg/dL), low-density lipoprotein (88.07 mg/dL), very low-density lipoprotein (25.2 mg/dL), atherogenic index, whereas a decrease in the levels of pancreatic insulin (97.48 ng/mg) and high-density lipoprotein (29.12 mg/dL). In addition, the activity of 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase (0.94 HMG-CoA ratio/(mevalonate) increased significantly in contrast to the activities of lipoprotein lipase (4.87 μmoles of glycerol liberated/h/L) and lecithin cholesterol acyltransferase (54.61 μmoles of cholesterol esterified/h/L) in diabetic rats. Treatment with myrtenal significantly (p < 0.05) improved the levels of plasma glucose, pancreatic insulin and lipid profiles. Moreover, the histopathological analysis of liver was also in agreement with the biochemical findings.
  
  
  CONCLUSIONS
  The present study indicates that myrtenal possess antihyperglycaemic and antihyperlipidemic properties, and could potentially be a useful phytochemical in treating diabetes.
authors.affiliation: a Department of Biochemistry and Biotechnology, Faculty of Science , Annamalai University , Annamalai Nagar , Tamil Nadu , India.
authors.forename: Rathinam
authors.initials: R
authors.lastname: Ayyasamy
authors.affiliation: a Department of Biochemistry and Biotechnology, Faculty of Science , Annamalai University , Annamalai Nagar , Tamil Nadu , India.
authors.forename: Pari
authors.initials: P
authors.lastname: Leelavinothan
mesh_terms: D000818:Animals; D000081008:Bicyclic Monoterpenes; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000473:pathology; D006943:Hyperglycemia / Q000188:drug therapy*; D006949:Hyperlipidemias / Q000188:drug therapy; D007328:Insulin / Q000032:analysis*; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008297:Male; D010179:Pancreas / Q000737:chemistry / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin; D013729:Terpenes / Q000627:therapeutic use*
chemical_list: D000081008:Bicyclic Monoterpenes; D007328:Insulin; D013729:Terpenes; D013311:Streptozocin; C061545:myrtenal
keywords: Antihyperglycaemic; antihyperlipidaemic; atherogenic index; histopathology