Effect of dietary fatty acids on hepatic and blood fatty acid profile and metabolic associated genes in obese mice

Objective The aim of this study was to determine the effects of dietary fatty acids on hepatic and blood fatty acid profile and metabolic associated genes in obese mice. Methods Eight-week-old male C57BL/6 mice were randomly divided into 7 groups with 10 cases in each group including control group, long-chain saturated fatty acid (LCSFA) group, medium-chain saturated fatty acid (MCSFA) group, n-3 polyunsaturated fatty acid (n-3 PUFA) group, n-6 polyunsaturated fatty acid (n-6 PUFA) group, monounsaturated fatty acid (MUFA) group and trans fatty acid (TFA) group, fed with normal-fat diet (providing 10% of total energy), lard high-fat diet, coconut oil high-fat diet, linseed oil high-fat diet, soybean oil high-fat diet, olive oil high-fat diet and 8% hydrogenated soybean oil high-fat diet respectively for 16 weeks. The fat-to-energy ratio of high-fat diet was 45%. The total energy of all diets was the same. After being fasted for 12 hours, the mice were anesthetized and the liver tissues were collected. Fatty acids composition in liver and blood samples were analyzed by gas chromatography. Real-time polymerase chain reaction (PCR) were used to measure the expression of hepatic and blood fatty acid metabolic associated genes. Oil red O staining was carried out to assess the hepatic lipid accumulation. Results Compared with the control group, significant hepatic and blood lipid accumulation were observed in the LCSFA, MCSFA, n-6 PUFA, MUFA and TFA groups. The n-3 PUFA group had less hepatic and blood lipid accumulation. Compared with the control group, the contents of total PUFA and total n-6 PUFA in the LCSFA group were significantly increased. The levels of total n-3 PUFA and total PUFA in the hepatic and blood of n-3 PUFA group were significantly rise up, but the content of total MUFA was significantly decreased. The levels of total n-6 PUFA, total n-3 PUFA and total PUFA in the n-6 PUFA group were significantly increased, but the contents of saturated fatty acid (SFA) and total MUFA were significantly reduced. The content of total SFA in the MUFA group was significantly decreased. The C18:1 n-9t (TFA) content in the TFA group was significantly increased (P<0.05). The expression level of hepatic fatty acid metabolism gene sterol regulatory element-binding protein-1c (SREBP-lc) mRNA in the LCSFA and MCSFA groups were significantly higher than those in the control and n-6 PUFA groups (P