Animal experiments

Specified pathogen-free (SPF) male C57BL/6 mice (SLAC laboratory animal co., LTD, Shanghai, China) were housed in a controlled environment (23 °C, 12 h daylight cycle, lights off at 18.00 h). The mice were acclimatized for 7 d after arrival with free access to water and a standard chow diet. The mice were then assigned randomly to three groups: control, model (HF) and intervention group (HF + NaB) (n = 15/group, 5 mice per cage). Mice from the control group were fed a standard diet. The HF group and HF + NaB group were fed a high-lard-fat and high-cholesterol diet (88% standard diet, 10% lard and 2% cholesterol). Body weight and food consumption were recorded weekly. Eight weeks after initiation of the experimental diets, we sacrificed 3 randomly selected mice from every group to assess liver damage. The intervention group was underwent daily intragastric administration with NaB at 200 mg/kg body weight (Sigma-Aldrich, United States), while the HF group received the same amount of normal saline once per day for 8 wk. After 8 wk of intervention, the mice were fasted for 12 h and blood or tissue samples were collected. All animals were euthanized by pentobarbital sodium for tissue collection.

All animal experiments were approved by the Institutional Animal Care and Use Committee of Xinhua hospital affiliated to Shanghai Jiao Tong University School of Medicine and were conducted in accordance with the National Research Council Guide for Care and Use of Laboratory Animals.