[Liver gene expression in normal and obese rats received resveratrol and L-carnitine]

Abstract

The use of nutraceuticals with anti-inflammatory and hypolipidemic activity in the composition of foods for special dietary uses and dietary supplements is one of the effective methods of dietary therapy of alimentary obesity and related diseases. The aim was to study the effect of the combined intake of resveratrol and L-carnitine (RC) on the expression of genes responsible for the metabolism of carbohydrates, fats and inflammatory reactions in the liver and kidneys of rats in normal conditions and with diet-induced obesity. Material and methods. Male Wistar rats received for 63 days a standard balanced diet or a high-fat-high-carbohydrate diet (HFCD) with an excess of total fat (30%) and fructose (20% solution instead of drinking water), or the same diets supplemented with RC in a low (25 mg/kg body weight as resveratrol and 300 mg/kg as L-carnitine) or high (50 and 600 mg/kg body weight, respectively) doses. The expression of genes (Khk, Gck, Pklr, Acaca, Acacb, Fasn, Scd, Srebf1, Mlxipl, Ppara, Pparg, Actb, Gapdh) in liver cells was studied by the method of real-time reverse transcription polymerase chain reaction (RT-PCR). The distribution of tyrosine aminotransferase (TAT), nuclear factor erythroid 2-related factor 2 (NRF-2) and intercellular adhesion molecule type 2 (ICAM-2) in the liver and kidneys was assessed by confocal laser microscopy and immunohistochemistry. Results. Increased expression of Fasn (fatty acid synthase) in rats treated with high-fat high-carbohydrate diet (HFCD) decreased under RC intake. RC consumption caused a decrease in the number of TAT-, NRF-2- and ICAM-2-positive cells in the liver of rats treated with HFCD, but had the opposite effect in the kidneys. The consumption of RC at the low dose by rats fed HFCD caused changes in the expression profiles of the studied marker genes, indicating a possible hypolipidemic effect. However, observed increased expression of lipogenic genes in the liver and elevated level of NRF-2 and ICAM-2 in kidney against the background of consumption of RC with the standard balanced diet cannot be assessed as unambiguously positive. Conclusion. Thus, possible negative effects caused, most likely, by the interaction of nutraceuticals with various mechanisms of action should be taken into account when developing formulations of dietary supplements and foods for special dietary uses for dietary therapy of obesity.

Keywords: carnitine; confocal microscopy; gene expression; obesity; polymerase chain reaction; rats; resveratrol.