A krill oil supplemented diet reduces the activities of the mitochondrial tricarboxylate carrier and of the cytosolic lipogenic enzymes in rats

The mitochondrial tricarboxylate carrier supplies cytosol with the carbon units necessary for hepatic lipogenesis. The activities of cytosolic acetyl-CoA carboxylase and fatty acid synthetase are therefore strictly connected to the function of mitochondrial tricarboxylate carrier. Dietary polyunsaturated fatty acids (PUFA) are potent modulators of hepatic lipogenesis. In rats fed with a diet enriched with a low dose (2.5% by weight) of krill oil (KO), a novel source of dietary n-3 PUFA, a time-dependent decrease in the activities of the mitochondrial tricarboxylate carrier and of the lipogenic enzymes was found. The KO induced inhibition of hepatic lipogenesis was more pronounced than that found in fish oil (FO)-fed rats, at least at short feeding times. The decrease in the activity of the mitochondrial tricarboxylate carrier caused by KO was due to a reduced expression of the protein and this effect is obtained by both transcriptional and post-transcriptional mechanisms. Furthermore, dietary KO reduces hepatic triglycerides and cholesterol more efficiently than FO and KO also lowers plasma triglycerides more efficiently than FO at shorter feeding times, whereas KO and FO similarly decreased plasma cholesterol in the course of feeding treatment. We believe that the present investigation opens up new possibilities regarding the use of dietary KO as a preventive factor for dyslipidaemia.