d -Allulose enhances uptake of HDL-cholesterol into rat’s primary hepatocyte via SR-B1

d-Allulose, a C-3 epimer of d-fructose, is a rare sugar and a non-caloric sweetener. d-Allulose is reported to have several health benefits, such as suppressing a rise in postprandial glucose levels and preventing fat accumulation in rodents and humans. Additionally, low HDL-cholesterol levels post-d-allulose feeding were observed in humans but it is unclear how d-allulose decreased HDL-cholesterol levels. It is necessary to research the mechanism of HDL-cholesterol reduction by d-allulose ingestion because low HDL-cholesterol levels are known to associate with increased atherosclerosis risk. We therefore investigated the mechanism by which d-allulose lowers HDL-cholesterol using rat’s primary hepatocytes. Sprague Dawley rats were fed an AIN-93G based diet containing 3% d-allulose for 2 weeks. Thereafter, primary hepatocytes were isolated by perfusion of collagenase. We measured the ability of HDL-cholesterol uptake in hepatocytes and the protein levels of scavenger receptor class B type 1 (SR-B1) as a HDL-cholesterol receptor. d-Allulose enhanced hepatocyte uptake of HDL-cholesterol, with a concurrent increase in hepatic SR-B1 protein levels. The results suggest that d-allulose enhances HDL-cholesterol uptake into the liver by increasing SR-B1 expression. It is estimated that HDL-cholesterol levels decreased accordingly. Since SR-B1 overexpression would decrease HDL-cholesterol levels, reportedly preventing atherosclerosis development, d-allulose could be a useful sweetener for atherosclerosis prevention.