Effects of herring roe on plasma lipid, glucose, insulin and adiponectin levels, and hepatic lipid contents in mice

Marine omega-3 phospholipids: metabolism and biological activities

The biological activities of omega-3 fatty acids (n-3 FAs) have been under extensive study for several decades. However, not much attention has been paid to differences of dietary forms, such as triglycerides (TGs) versus ethyl esters or phospholipids (PLs). New innovative marine raw materials, like krill and fish by-products, present n-3 FAs mainly in the PL form. With their increasing availability, new evidence has emerged on n-3 PL biological activities and differences to n-3 TGs. In this review, we describe the recently discovered nutritional properties of n-3 PLs on different parameters of metabolic syndrome and highlight their different metabolic bioavailability in comparison to other dietary forms of n-3 FAs.

Fish nutrients decrease expression levels of tumor necrosis factor-α in cultured human macrophages

Numerous studies have demonstrated the beneficial effects of fish consumption on inflammatory markers. Until now, these beneficial effects of fish consumption have been mostly linked to the omega-3 fatty acids (FA). The objective of the present study was to examine, in vitro, whether expression levels of genes involved in the inflammatory response differ in human macrophages incubated with casein hydrolysates (CH) or fish protein hydrolysates (FPH) in the presence or absence of omega-3 FA compared with omega-3 FA alone. Peripheral blood monocytes differentiated into macrophages from 10 men were incubated in the presence of omega-3 FA (10 μM eicosapentaenoic acid and 5 μM docosahexaenoic acid) or CH or FPH (10, 100, 1,000 μg) with or without omega-3 FA for 48 h. Results demonstrate that expression levels of tumor necrosis factorα ( TNFα) had a tendency to be lower after the addition of FPH alone or CH with omega-3 FA compared with omega-3 FA treatment. Furthermore, the combination of FPH and omega-3 FA synergistically decreased expression levels of TNFα compared to treatment with omega-3 FA or FPH alone. No difference on gene expression levels of interleukin-6 was observed between treatments. In conclusion, these preliminary results suggest that the anti-inflammatory effects of fish consumption can be explained by a synergistic effect of the omega-3 FA with the protein components of fish on TNFα expression and therefore contribute to the beneficial effects of fish consumption. Hence, follow-up studies should be performed to confirm the effects of a diet rich in FPH and omega-3 FA on serum proinflammatory cytokine concentrations.