Individual and combined effects of docosahexaenoic acid, stearic acid, trans‐vaccenic acid, and c9,t11‐conjugated linoleic acid on hepatic gene expression

Abstract

Dietary long-chain fatty acids (LCFA), polyunsaturated fatty acids (PUFA) and their combinations alter metabolism by modulating expression of fatty acid synthase (FAS), carnitine palmitoyltransferase-1a (CPT-1a), and acyl-CoA oxidase (ACO). The effects of LCFA and PUFA on mRNA expression were determined in H4IIE rat hepatoma cells incubated with docosahexaenoic acid (DHA), c9, t11-conjugated linoleic acid (CLA), trans-vaccenic acid (TVA), and stearic acid (SA) or their combinations. Treatments were: 200 μM of individual fatty acids DHA, CLA, SA, or TVA; Replacement of 100 μM DHA with either 100 μM CLA or 100 μM SA; 100 μM CLA replaced by 100 μM TVA (final fatty acid concentration of 200 μM); 200 μM of DHA or CLA supplemented with 200μM of CLA, SA, or TVA. When CLA replaced DHA, FAS mRNA decreased by 53.7% (P< 0.05). Replacement of DHA with SA resulted in a 74.9% decrease (P< .05) in FAS mRNA. When 200 μM CLA was supplemented with 200 μM DHA or with 200 μM TVA, FAS mRNA decreased (P< 0.05) by 62.4% and 48.6% respectively. When CLA was replaced with TVA, CTP-1a mRNA tended (P= 0.05) to decrease by 47.5%. When CLA was supplemented with DHA there was a tendency (P< 0.10) for a 40.2% decrease in CPT-1a mRNA. Fatty acid concentration and mixture had no effect on ACO mRNA. The data suggest that individual and combined LCFA/PUFA exert different potencies on expression of genes for fatty acid metabolism in liver.