Hypolipidemic effects of a new piperine derivative GB-N from Piper longum in high-fat diet-fed rats

Abstract

Context: Long pepper, Piper longum Linn. (Piperaceae), is widely used in traditional Mongolian medicine for treating hyperlipidemia and coronary heart disease. Objective: To investigate the hypolipidemic effects of a new piperine derivative GB-N isolated from long pepper in high-fat diet-fed rats. Methods: The levels of serum total cholesterol, triacylglycerols (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were determined by enzymatic colorimetric method. The levels of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), CYP7A1, lecithin cholesterol acyltransferase (LCAT) and LDL receptor (LDLR) mRNA and protein expression were detected by real-time polymerase chain reaction and western blot analysis. Results and discussion: Compared with model rats, oral administration of GB-N at doses of 2.5-10mg/kg to hyperlipidemic rats could significantly decrease the levels of serum TG from 1.54 mmol/L in hyperlipidemic rats to 0.94-1.02 mmol/L, with an increase in serum HDL-C levels from 0.40 mmol/L in hyperlipidemic rats to 1.21-2.26 mmol/L. Treatment with GB-N (10mg/kg) could also significantly upregulate levels of hepatic HMG-CoA reductase, CYP7A1, LCAT and LDLR mRNA and protein expression. Conclusion: GB-N had hypolipidemic activity via regulating lipid metabolism pathways in liver of hyperlipidemic rats and could be explored as a potential agent for the prevention of hyperlipidemia diseases. © 2012 Informa Healthcare USA, Inc.