Dietary Starfish Oil Prevents Hepatic Steatosis and Hyperlipidemia in C57BL/6N Mice Fed High-fat Diet

Starfish oil (SO) is characterized by functional lipids, including n-3 polyunsaturated fatty acid (both in the form of triacylglycerol and in the form of phospholipid), and carotenoids, which may exert beneficial effects on metabolic disorders in obesity-associated diseases. In the present study, the effect of SO on dysregulation of lipid metabolism was examined using C57BL/6N mice treated with high-fat (HF) diet. Mice were fed HF, HF with 2% SO, or HF with 5% SO diet for 8 weeks. Weight gain, blood glucose, serum and hepatic lipid contents, and hepatic fatty acid composition were measured. Fatty acid β-oxidation activity was monitored by measuring the catabolic rate of 13C-labeled fatty acid, assessed as 13CO2/12CO2 ratio using isotope ratio mass spectrometry (IR-MS). Although there were no differences in body weight or white adipose tissue weight among the test groups, dietary SO reduced blood glucose, and dose-dependently improved hyperlipidemia and decreased hepatic lipid accumulation. Analysis of hepatic fatty acid composition revealed a significant decrease in the ratio of monounsaturated fatty acid to saturated fatty acid, which is attributed to stearoyl-CoA desaturase activity. IR-MS analysis suggested that β-oxidation activity was enhanced in the mice treated with 5% SO. These results demonstrate that dietary SO improves lipid metabolism measures in HF diet-induced obese mice, suggesting that SO holds promise as an agent for the prevention and treatment of lipid metabolism disorders in the liver.