Dietary n-3 long-chain polyunsaturated fatty acids modify phosphoenolpyruvate carboxykinase activity and lipid synthesis from glucose in adipose tissue of rats fed a high-sucrose diet

Vitamin B12 Deficiency Across Three Generations Adversely Influences Long-chain Polyunsaturated Fatty Acid Status and Cardiometabolic Markers in Rats

BACKGROUND AND AIMS

Vitamin B₁₂ and omega-3 fatty acid deficiency is prevalent in the vegetarian population and is associated with adverse pregnancy outcomes and cardiometabolic risk. The present study investigates the long-term effects of vitamin B₁₂ deficiency/supplementation in the presence of omega-3 fatty acids on cardiometabolic profile and long-chain polyunsaturated fatty acid levels (LCPUFA) in the F₃ generation offspring.

METHODS

Three generations of rats were fed the following diets: control; vitamin B₁₂ deficient; vitamin B₁₂ supplemented; vitamin B₁₂ deficient + omega-3 fatty acid supplemented; vitamin B₁₂ + omega-3 fatty acid supplemented. Animals were sacrificed at 3 months of age.

RESULTS

Vitamin B₁₂ deficiency lowered (p <0.01 for both) plasma eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), liver DHA (p <0.05), plasma/liver omega-3 fatty acids (p <0.05 for both), increased triglycerides (p <0.05) and systolic BP (p <0.01) and lowered cholesterol levels (p <0.05) as compared to control. Vitamin B₁₂ deficiency in the presence of omega-3 fatty acids improved plasma/liver EPA, DHA and omega-3 fatty acid profile and maintained cholesterol, triglyceride and BP levels. Vitamin B₁₂ supplementation lowered liver DHA (p <0.05) and cholesterol (p <0.01), whereas BP was similar to control. Combined supplementation of vitamin B₁₂ and omega-3 fatty acids improved omega-3 fatty acid profile, lowered cholesterol/triglyceride levels and maintained the BP similar to that of control.

CONCLUSION

Vitamin B₁₂ deficiency across three generations adversely affects LCPUFA and cardiometabolic profile in the adult offspring. This study provides clues for a combined supplementation of vitamin B₁₂ and omega-3 fatty acids to reduce the risk for noncommunicable diseases.

Dietary Effects of Oxidized Eicosapentaenoic Acid (EPA) and Intact EPA on Hepatic Steatosis Induced by a High-sucrose Diet and Liver-X-receptor α Agonist in Mice

Numerous studies have shown that dietary omega-3 polyunsaturated fatty acids (PUFAs), particularly eicosapentaenoic acid (EPA), improve lipid metabolism. The beneficial effects of PUFA-derived oxidation products have been increasingly reported. However, EPA is easily oxidized in food products and in the human body, generating various derivatives of oxidized EPA (oxEPA), such that these oxidation products may partially contribute to EPA's effect. We previously reported that oxEPA was more potent than intact EPA in reducing liver-X-receptor α (LXRα)-induced cellular triacylglycerol (TG) accumulation. However, the in vivo hypolipidemic effects of oxEPA remain unclear. In the present study, we evaluated the effect of oral administration of EPA and oxEPA on hepatic steatosis in mice induced by a high-sucrose diet and a synthetic LXRα agonist, TO-901317. Both EPA and oxEPA reduced TG accumulation in the liver and plasma biomarkers of liver injury. Furthermore, they suppressed the expression of lipogenic genes, but not β-oxidation genes, in a similar pattern as the biomarkers. Our results suggest that oxEPA and intact EPA suppress de novo lipogenesis to ameliorate hepatic steatosis.