l -Arabinose improves hypercholesterolemia via regulating bile acid metabolism in high-fat-high-sucrose diet-fed mice

Background Hypercholesterolemia is closely associated with an increased risk of cardiovascular diseases. l -Arabinose exhibited hypocholesterolemia properties, but underlying mechanisms have not been sufficiently investigated. This study aimed to elucidate the mechanisms of l -arabinose on hypocholesterolemia involving the enterohepatic circulation of bile acids. Methods Thirty six-week-old male mice were randomly divided into three groups: the control group and the high-fat-high-sucrose diet (HFHSD)-fed group were gavaged with distilled water, and the l -arabinose-treated group were fed HFHSD and received 400 mg/kg/day l -arabinose for 12 weeks. Serum and liver biochemical parameters, serum and fecal bile acid, cholesterol and bile acid metabolism-related gene and protein expressions in the liver and small intestine were analyzed. Results l -Arabinose supplementation significantly reduced body weight gain, lowered circulating low-density lipoprotein cholesterol (LDL-C) while increasing high-density lipoprotein cholesterol (HDL-C) levels, and efficiently alleviated hepatic inflammation and lipid accumulations in HFHSD-fed mice. l -Arabinose inhibited cholesterol synthesis via downregulation of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR). Additionally, l -arabinose might facilitate reverse cholesterol transport, evidenced by the increased mRNA expressions of low-density lipoprotein receptor (LDL-R) and scavenger receptor class B type 1 (SR-B1). Furthermore, l -arabinose modulated ileal reabsorption of bile acids mainly through downregulation of ileal bile acid-binding protein (I-BABP) and apical sodium-dependent bile acid transporter (ASBT), resulting in the promotion of hepatic synthesis of bile acids via upregulation of cholesterol-7α-hydroxylase (CYP7A1). Conclusions l -Arabinose supplementation exhibits hypocholesterolemic effects in HFHSD-fed mice primarily due to regulation of bile acid metabolism-related pathways.