Virgin flaxseed oil supplemented or not with tocopherols and phytosterols prevents liver steatosis induced by high-fat diets in male Wistar rats

Abstract

This study aimed to investigate the effect of a virgin flaxseed oil (FO) rich in n − 3 polyunsaturated fatty acid, supplemented or not with a bioactive supplement (BS) containing tocopherols and phytosterols on the prevention of nonalcoholic fatty liver disease in a high-fat (HF) animal model. Male Wistar rats were fed 60 days with a recommended (SO7, soybean oil 7%) or an HF diet (fat, 30%) containing soybean (SO30), corn (CO30), or FO (FO30) or the same oils supplemented with 1% of BS (SO30BS, CO30BS, or FO30BS, respectively). Hepatic and dietary FA composition, triacylglycerides (TAGs) content in serum and liver, nutritional parameters, in vivo TAG-secretion rate, liver histology, mRNA levels of β-oxidation-related genes, and carnitine palmitoyl transferase-1a (CPT-1a) enzyme activity were determined. At HF levels, FO30 and FO30BS groups showed the highest total n − 3 PUFA levels in diets and were associated with lower weight gain, liver TAG content, and microsteatosis degree. The CPT-1a activity was enhanced in FO30 and FO30BS, showing differences only by the type of dietary oil. The BS supplementation induced an increase in the β-oxidation-related gene expression. Virgin FO prevented liver steatosis and hepatomegaly induced by HF diets. The BS supplementation reduced body fat accumulation and enhanced expression of β-oxidation related genes, without affecting hepatic TAG content.

Practical Applications: Scientific knowledge of functional lipids with high oxidative stability and biological activity has great practical application in reducing non-communicable chronic diseases. This study provides evidence on the potential synergic and complementary effects of virgin FO, TP, and PS to be used for the prevention of the metabolic hepatic disorders involved during the evolution of the different steps of NAFLD. Specifically, based on different biological mechanisms, this stable combination of bioactive lipids could prevent not only the development of exacerbated hepatic TAG accumulation but also the hepatocellular injury seen at different stages from hepatic steatosis to steatohepatitis.