The effect of a high-fat diet and phytocomposition based on B. vulgaris, C. bergamia, D. villosa and L. meyenii on the expression of genes for carbohydrate and lipid metabolism enzymes in the liver of rats

Introduction. The liver serves as a buffer for the accumulation and utilization of excess intake of nutritional fats, the intake of plant compounds can improve metabolic processes in the liver, but the molecular mechanisms of this phenomenon have been little studied.

The purpose of the study. To study the effect of oral administration of a phytocomposition based on B. vulgaris, C. bergamia, D. villosa and L. meyenii (PC) on the expression levels of carbohydrate and lipid metabolism genes in the liver of rats on a standard diet (SD) or a high-fat diet (HFD).

Material and methods. 48 male Wistar rats were divided into groups (G) of equal numbers. During 4 and 7 weeks, animals G1 and G5, respectively, received SD (the proportion of fat in total calories was 11%), G2 and G6 – SD+PC, G3 and G7 – HFD (the proportion of fat in total calories was 36% due to the addition of lard to the diet), G4 and G8 – HFD+PC. After the animals were removed from the experiment, the liver was fixed in 1 ml of «Riti» reagent (Diem, Russia) and stored at -20 °C until the study. The expression of the genes acetyl-CoA carboxylase A (Acaca), acetyl-CoA carboxylase B (Acacb), fatty acid synthase (Fasn), stearyl-CoA desaturase (Scd), glucokinase (Gck) and pyruvate kinase (Pklr) was determined in the liver by reverse transcription polymerase chain reaction.

Results and discussion. It has been shown that HFD causes phase changes in the expression of lipid and carbohydrate metabolism genes in the rat liver: at week 4, there is an increase in Fasn expression, a decrease in Acaca and Pklr, indicating activation of lipogenesis; at week 7, a decrease in Fasn and Acacb expression, indicating activation of β-oxidation of fatty acids, an increase in the expression of Gck and Acaca indicates an increase in glycogenogenesis. The administration of PC potentiates these compensatory shifts, significantly enhancing the expression of Acaca and Gck. Correlation analysis showed that taking PC in SD conditions increased the number of correlations from 2 to 6 (new connections: Acacb and Pklr with Fasn and Scd), and in HFD conditions it transformed the feedback Acaca with Acacb into direct Acaca with Gck and Pklr.

Conclusion. The data obtained indicate that biologically active compounds of the studied PC contribute to the enhancement of the conjugation of carbohydrate and lipid metabolism and the activation of glycogenogenesis in the liver due to their direct or indirect action as inducers of lipid and carbohydrate metabolism gene expression, thereby leading to a restructuring of metabolic pathways aimed at compensating for HFD.