Plasma cholesterol-lowering activity of piperine is mediated by inhibition on cholesterol absorption via down-regulation of intestinal ACAT2 and MTP

Abstract

Piperine is the major pungent ingredient in black and white peppers. The present study investigated plasma cholesterol-lowering activity of piperine and associated underlying mechanism in hypercholesterolemia hamsters. Thirty-two hamsters were assigned into four groups receiving one of four diets namely a non-cholesterol diet (NCD), a high-cholesterol diet (HCD), and the two HCD diets containing 0.03% (PL) and 0.06% (PH) piperine, respectively, for 6 weeks. Results showed that PL and PH diets significantly reduced plasma total cholesterol (TC) by 16–17%, and non-high-density lipoprotein cholesterol (non-HDL-C) by 24–25%, respectively. This was accompanied by 84–109% increase in fecal excretion of neutral sterols with down-regulation on gene expression of intestinal Niemann-Pick C1-like 1 protein (NPC1L1), acyl-CoA:cholesterol acyltransferase 2 (ACAT2), and microsomal triacylglycerol transport protein (MTP). It was concluded that plasma TC-lowering activity of piperine was mediated by reducing the intestinal cholesterol absorption via inhibition on gene expression of intestinal NPC1L1, ACAT and MTP.