LIPID-LOWERING EFFICACY OF PIPERINE FROM PIPER NIGRUM L. IN HIGH-FAT DIET AND ANTITHYROID DRUG-INDUCED HYPERCHOLESTEROLEMIC RATS

Abstract

Male Wistar rats were divided into two groups: control diet group and high-fat diet group (HFD). Both groups were divided into four subgroups, each consisted of 10 animals, and the diets were supplemented with the following ingredients for 10 weeks: (1) 1% carboxymethyl cellulose; (2) 10 mg carbimazole (CM)/kg body weight; (3) 10 mg CM + 40 mg piperine/kg body weight; and (4) 10 mg CM + 2 mg atorvastatin/kg body weight. Feeding HFD to rats significantly (P < 0.05) elevated plasma total cholesterol, triglycerides, phospholipids, free fatty acids, low-density lipoprotein (LDL), very low-density lipoprotein (VLDL) and the activity of 3-hydroxy 3-methyl glutaryl coenzyme A (HMG CoA) reductase in the liver, heart and aorta, while the activities of plasma and tissue lipoprotein lipase (LPL) and plasma lecithin cholesterol acyl transferase (LCAT) and high-density lipoprotein were significantly (P < 0.05) lowered compared to control rats. Supplementing piperine with HFD significantly (P < 0.05) reduced the levels of plasma total cholesterol, LDL, VLDL tissue HMG CoA reductase and significantly (P < 0.05) elevated the levels of LPL and LCAT compared to rats that did not receive piperine. Fecal bile acids and neutral sterols were also elevated in HFD-fed rats as compared to control animals, while simultaneous supplementation of piperine significantly (P < 0.05) enhanced further excretion of bile acids and neutral sterols. The results indicate that piperine can prevent the accumulation of plasma lipids and lipoproteins significantly by modulating the enzymes of lipid metabolism.