Spicy foods emerge as promising nutraceutical therapies for

Spicy foods emerge as promising nutraceutical therapies for treating hyperchloremia in recent years (Zhao & Chen, 2018). Although black pepper is the most widely consumed spicy food, clinical trials regarding its effects on blood cholesterol are still lacking (Zhao & Chen, 2018). Therefore, the present study serves as in vivo evidence to demonstrate that piperine possesses a plasma cholesterol-lowering activity, which should be tested in human trials in the future.
Conflict of interest
Animal experiment ethical file
Acknowledgement This project was partially supported by a grant from the Health and Medical Research Fund, The Food and Health Bureau, The Government of the Hong Kong Special Administrative Region, China (Project No. 13140111).
Introduction Atherosclerosis is the major cause of coronary heart disease caused by dysfunction in lipoprotein cholesterol metabolism [1]. Excessive iMDK australia of dietary and biliary cholesterol into the intestine and dysregulation in cholesterol homeostasis result in elevated plasma cholesterol levels, which may promote the development of atherosclerosis [2]. Several animal studies have demonstrated that a reduction in intestinal cholesterol absorption exerts strong cholesterol-lowering and atheroprotective effects [3], [4]. Cholesterol absorption in the small intestine has been recently identified to be mediated by Niemann-Pick C1-like 1 (NPC1L1) protein, a key transporter for intestinal cholesterol absorption [5]. NPC1L1 is highly expressed in the mucosa of the small intestine and is required for cholesterol absorption [5]. Deficiency or inhibition of NPC1L1 in mice causes a marked reduction in cholesterol absorption [5] and is completely resistant to diet-induced hypercholesterolemia [6], [7] and atherosclerosis caused by apolipoprotein E (ApoE) deficiency [4], [8]. Curcumin is a polyphenol extracted from turmeric, which is commonly used as a spice and food-coloring agent in many cultures [9]. Curcumin possesses anti-inflammatory, antioxidant, and cancer-preventive properties [10], [11], [12]. In addition to these well-known effects, consuming curcumin may benefit health by modulating lipid metabolism and suppressing atherosclerosis. Many studies in animals and humans have demonstrated that curcumin supplementation exerts hypocholesterolemic effects [13], [14], [15], [16], [17]. Furthermore, the antiatherogenic effects of curcumin have recently been demonstrated in animal models [18], [19], [20]. Shin et al showed that long-term curcumin administration lowered blood and hepatic cholesterol and prevented the development of atherosclerosis in LDLR−/− mice [19]. In rabbits fed a high-cholesterol diet, curcumin supplementation reduced oxidative stress and suppressed the formation of aortic fatty streaks [18]. High cholesterol is an important risk factor for atherosclerosis, and reduced cholesterol absorption has been found to cause a decrease in plasma cholesterol levels and atherosclerosis formation [8], [21]. Previously, we reported that curcumin treatment exhibits a hypocholesterolemic effect in high-fat–fed hamsters via the inhibition of intestinal cholesterol absorption, which is mediated by the downregulation of intestinal NPC1L1 [14].