The potential mechanisms of bergamot-derived dietary fiber alleviating high-fat diet-induced hyperlipidemia and obesity in rats

This study is aimed to investigate the health-associated benefits of bergamot-dietary fibers (DFs) with a special emphasis on weight loss and lipid-lowering effects, as well as the potential mechanisms involved. The feeding experiment of Sprague-Dawley (SD) rats for 6 weeks showed that DFs had dose-dependent regulatory effects against metabolic syndrome and they controlled obesity by slowing down the rate of weight growth, and reduced body mass index (BMI) and Lee's index without affecting appetite. Furthermore, DFs inhibited increment in TG, TC, LDL-C levels and AI index caused by a high-fat diet, and improved the pathological abnormality of the liver. Western blot results showed that DFs significantly up-regulated the protein expression levels of LXRα and CYP7A1, and down-regulated the levels of SREBP-1c, FAS, ACC and SREBP-2 in the liver. QRT-PCR results showed that DFs up-regulated PGC-1α, PRDM16, UCP-1, and PPARγ in brown adipose tissue. These results suggest that DFs played an effective role in reducing weight and lipids levels by promoting the decomposition and transport of lipids in liver, increasing the energy consumption of brown adipose tissue. DFs intervention reduced the difference in the intestinal microflora between rats fed with a normal diet and those fed with a high-fat diet. Soluble dietary fiber (SDF) and total dietary fiber (TDF) showed better weight loss and hypolipidemic potential compared to insoluble dietary fiber (IDF) at the same dose. In conclusion, bergamot-derived DFs demonstrated the potential to lower blood cholesterol and body weight and could be used to develop novel functional foods for the prevention or treatment of obesity and hyperlipidemia.