Myrtenal alleviates hyperglycaemia, hyperlipidaemia and improves pancreatic insulin level in STZ-induced diabetic rats

Abstract

Context: 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. Materials and 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), lowdensity 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 lmoles of glycerol liberated/h/L) and lecithin cholesterol acyltransferase (54.61 lmoles 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. Discussion and conclusions: The present study indicates that myrtenal possess antihyperglycaemic and antihyperlipidemic properties, and could potentially be a useful phytochemical in treating diabetes. ARTICLE HISTORY

Effect of N-Acetylcysteine on Dyslipidemia and Carbohydrate Metabolism in STZ-Induced Diabetic Rats

“…In this paper, there was an increase in total cholesterol, LDL-cholesterol, triacylglycerols, VLDL-cholesterol, and low HDL-cholesterol in diabetic rats (DM) ( Table 3 ), confirming the development of dyslipidemia in this pathology, which is supported by previous studies [ 54 , 55 ].…”

“…T1DM causes an insulin deficiency, resulting in increased lipolysis and subsequent β -oxidation of acetyl-CoA, which can be used in lipogenesis together with HMG-CoA reductase, a key enzyme in cholesterol biosynthesis [ 55 ], promoting the hepatic formation of VLDL-cholesterol and consequently increasing serum levels of cholesterol and LDL-cholesterol. Fatty acids that are not β -oxidated are esterified into triacylglycerols, which are incorporated into VLDL-cholesterol in the liver and exported to the bloodstream [ 10 ].…”

“…These metabolic events increase lipoproteins to a value above normal, identifying dyslipidemia as a risk factor for the development of atherosclerosis [ 55 ].…”

“…Studies have shown that NAC increases insulin secretion [ 45 , 46 ]. On the other hand, the presence of insulin increases the activity of lipoprotein lipase, which catalyzes the breaking of triacylglycerol ester bonds, increasing the clearance of VLDL-cholesterol [ 55 , 58 ].…”

Antidiabetic Potential of Monoterpenes: A Case of Small Molecules Punching above Their Weight

“…The remarkable feature of monoterpenes is that they have shown promising antidiabetic effect in vivo despite their rather simplistic structural appearance [ 35 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 ]. The list of monoterpenes with good effects on in vivo antidiabetic models including in the streptozotocin (STZ)-induced diabetic, high fat diet (HFD) fed and spontaneously obese mouse models are shown in Table 2 .…”