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.

胡椒碱是黑胡椒和白胡椒中的主要刺激性成分。本研究调查了高胆固醇血症仓鼠血浆中胡椒碱的胆固醇降低活性及其相关的潜在机制。将三十二只仓鼠分为四组，分别接受四种饮食中的一种，即非胆固醇饮食（NCD），高胆固醇饮食（HCD）和两种包含0.03％（PL）和0.06％（PH）的HCD饮食胡椒碱分别放置6周。结果表明，PL和PH饮食分别使血浆总胆固醇（TC）降低了16–17％，非高密度脂蛋白胆固醇（non-HDL-C）降低了24–25％。伴随着肠道Niemann-Pick C1样1蛋白（NPC1L1），酰基辅酶A的基因表达下调，中性固醇的粪便排泄增加84-109％：胆固醇酰基转移酶2（ACAT2）和微粒体三酰基甘油转运蛋白（MTP）。结论是通过抑制肠道NPC1L1，ACAT和MTP的基因表达来降低肠道胆固醇的吸收来介导胡椒碱降低血浆TC的活性。