A new piece in the puzzling effect of n-3 fatty acids on atherosclerosis?

Addition of fish oil to atherogenic high fat diet inhibited atherogenesis while olive oil did not, in LDL receptor KO mice

BACKGROUND AND AIMS

Mediterranean diet has been associated with decreased cardiovascular morbidity and mortality. Both fish and olive oil are key components of this diet. Therefore, we compared their effects on nonalcoholic fatty liver disease (NAFLD) and atherogenesis in a mouse model, fed a high fat diet.

METHODS AND RESULTS

Forty nine, female LDL receptor knockout (LDLR KO) mice were allocated into 3 groups and fed an atherogenic high fat (HF) diet for 9 weeks. The HF group was fed a high fat diet alone. A HF + OO group was fed a HF diet with added olive oil (60 ml/kg feed), and the third group (HF + FO) was fed a HF diet with added fish oil (60 ml/kg feed). Both additions of fish and olive oil, significantly decreased plasma cholesterol elevation compared to HF diet. Nevertheless, only fish oil addition reduced significantly atherosclerotic lesion area by 51% compared to HF group. Liver levels of eicosapentenoic (EPA) and docosahexaenoic (DHA) acids were several folds higher in HF + FO group than in HF and HF + OO groups. Liver levels of oleic acid were higher in HF + OO compared to the other groups. Moreover, Fish oil addition significantly decreased NAFLD scores related to steatosis and inflammation and lowered the expression of the inflammatory genes interleukin 6 (IL6) and monocyte chemoattractant protein 1 (MCP1).

CONCLUSION

These results suggest that fish oil addition on top of an atherogenic, HF diet, is beneficial, while olive oil is not, in its effect on plaque formation and NAFLD in LDLR KO mice.

Effect of Dietary Components from Antarctic Krill on Atherosclerosis in apoE-Deficient Mice

SCOPE

Antarctic krill is a great source of n-3 fatty acids and high-quality proteins. Aim of the study was to evaluate the effect of Antarctic krill components on plasma lipids and atherosclerosis development.

METHODS AND RESULTS

Sixty apoEKO mice were divided into four groups and fed Western diet (CONTROL) or Western-like diets, differing for protein or fat content. Specifically, casein or fat in CONTROL was partially replaced by krill proteins (PRO), krill oil (KRILL OIL), or both (KRILL OIL+PRO). In KRILL OIL+PRO and KRILL OIL, cholesterol levels were significantly lower than in CONTROL group. Atherosclerosis in aorta of PRO, KRILL OIL and KRILL OIL+PRO was lower than in CONTROL, whereas, at the aortic sinus, atherosclerosis reduction was only observed in KRILL OIL. Liver steatosis, commonly present in CONTROL and PRO animals, was sporadic in KRILL OIL+PRO and KRILL OIL mice. Krill oil containing diets affected the expression of genes involved in cholesterol metabolism, mainly HMG-CoA reductase. No reduced systemic inflammation was found in all groups.

CONCLUSION

Krill oil containing diets were able to reduce cholesterol levels, inhibit plaque development and prevent liver damage. Krill proteins also reduced atherosclerosis development through mechanisms not involving lipid metabolism.

A Unique Combination of Nutritionally Active Ingredients Can Prevent Several Key Processes Associated with Atherosclerosis In Vitro

Introduction

Atherosclerosis is the underlying cause of cardiovascular disease that leads to more global mortalities each year than any other ailment. Consumption of active food ingredients such as phytosterols, omega-3 polyunsaturated fatty acids and flavanols are known to impart beneficial effects on cardiovascular disease although the combined actions of such agents in atherosclerosis is poorly understood. The aim of this study was to screen a nutritional supplement containing each of these active components for its anti-atherosclerotic effect on macrophages in vitro.

Results

The supplement attenuated the expression of intercellular adhesion molecule-1 and macrophage chemoattractant protein-1 in human and murine macrophages at physiologically relevant doses. The migratory capacity of human monocytes was also hindered, possibly mediated by eicosapentaenoic acid and catechin, while the ability of foam cells to efflux cholesterol was improved. The polarisation of murine macrophages towards a pro-inflammatory phenotype was also attenuated by the supplement.

Conclusion

The formulation was able to hinder multiple key steps of atherosclerosis development in vitro by inhibiting monocyte recruitment, foam cell formation and macrophage polarisation towards an inflammatory phenotype. This is the first time a combination these ingredients has been shown to elicit such effects and supports its further study in preclinical in vivo models.