Combined functional lipids modulate lipid metabolism and attenuate metabolic dysregulation in a rat model of cafeteria diet

Abstract

Functional lipids (FL), including n-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA), modulate lipid composition and gene expression, potentially mitigating lipid accumulation and related metabolic disorders. This study investigated whether the combination of FL (cFL), derived from virgin flaxseed oil (vFO) and CLA, prevent cafeteria (CAF) diet-induced metabolic dysfunctions, under the hypothesis that they could exert beneficial synergetic effects. Male Wistar rats were fed control diet (C), CAF, or CAF enriched with FL (vFO, CLA, or both -cFL-) for 10 weeks. Nutritional parameters, body composition, serum and hepatic triacylglycerol (TAG), tissue fatty acid (FA) profile, enzymatic activities, and genes involved in lipid metabolism were evaluated. CAF diet increased energy intake (EI), fat depots and body weight. CLA and cFL attenuated body weight and adipose tissue (AT) gain, despite similar EI. In CAF, hepatic TAG increased whereas serum TAG levels decreased, likely reflecting enhanced lipoprotein lipase (LPL) activity together with reduced TAG secretion rate (TAG-SR) and microsomal triglyceride transfer protein (MTTP) expression. vFO and cFL groups modulated FA composition, increasing n-3 PUFA and reducing n-6 PUFA. CLA and cFL groups decreased hepatic TAG with enhanced β-oxidation. Nutrigenomic analysis revealed changes in several genes, indicating transcriptional regulation of lipid metabolism in FL-enriched groups. In summary, cFL improved nutritional parameters and prevented hepatic TAG accumulation by enhancing lipid oxidation and TAG-SR, linked to transcriptional and post-transcriptional regulation of lipid metabolism genes. cFL exerted synergistic effects, improving metabolic profile and mitigating CAF-induced alterations, supporting their potential application in precision nutrition strategies.