Protective effect of rutin on lipids, lipoproteins, lipid metabolizing enzymes and glycoproteins in streptozotocin-induced diabetic rats.

The protective role of rutin on lipids, lipoproteins, lipid metabolizing enzymes and glycoproteins in streptozotocin-induced diabetic rats has been studied. A single intraperitoneal injection of streptozotocin (50 mg kg(-1)) to rats led to a significant (P < 0.05) increase in the levels of lipids (cholesterol, triglycerides, free fatty acids and phospholipids) in plasma and tissues (liver, kidney, heart and brain). The levels of low density and very low density lipoprotein (LDL and VLDL, respectively) cholesterol were increased, whereas the levels of high density lipoprotein (HDL) cholesterol were decreased significantly (P < 0.05) in plasma. The activity of 3-hydroxy 3-methylglutaryl coenzyme A (HMG CoA) reductase increased significantly (P < 0.05) in liver, kidney and heart, and the activity of lipoprotein lipase (LPL) and lecithin cholesterol acyltransferase (LCAT) decreased significantly (P < 0.05) in the plasma of diabetic rats. Streptozotocin injection also increased the levels of glycoproteins such as hexose, hexosamine, fucose and sialic acid in plasma, liver and kidney. Oral administration of rutin to streptozotocin-induced diabetic rats significantly (P < 0.05) decreased the levels of lipids in plasma and tissues. The levels of plasma HDL-cholesterol increased and the levels of LDL- and VLDL-cholesterol decreased significantly (P < 0.05). The activity of HMG CoA reductase decreased in the tissues and the activity of plasma LPL and LCAT increased significantly (P < 0.05). The levels of glycoproteins were found to be significantly (P < 0.05) decreased in plasma, liver and kidney of rutin-treated diabetic rats. Rutin administration to normal rats did not exhibit any significant (P < 0.05) changes in any of the parameters studied. In conclusion, the beneficial effect of rutin on lipids, lipoproteins, lipid metabolizing enzymes and glycoproteins could be due to its antioxidant property.