[Effect of blueberry and blackcurrant anthocyanins on metabolic disorders in rats with alimentary obesity].

Abstract

Obesity is one of the most current problems of modern public health care, due to its significant contribution to the development of metabolic disorders leading to the manifestation of associated pathologies, including non-alcoholic fatty liver disease and diabetes mellitus. The main reason for the observed increase in the obesity prevalence among the population of developed countries in recent decades is considered to be changes in lifestyle, including excessive calorie intake along with increased content of saturated fats and simple carbohydrates in the diet. Bioactive compounds of plant origin are presently viewed as promising regulators of metabolic processes. Particular attention of researchers is drawn to anthocyanins - polyphenolic compounds contained in significant amounts in blueberries and blackcurrants. The aim of the research was to study the effects of blueberry and blackcurrant anthocyanins on metabolic disorders in rats with alimentary obesity.

Material and methods: A prospective study was conducted on male Wistar rats (with an initial body weight of 72.0±0.8 g) fed for 13 weeks a semi-synthetic balanced diet (group 1, n=8); a high-calorie choline-deficient diet (HCCDD) (group 2, n=8); and a high-calorie choline-deficient diet supplemented with bilberry and blackcurrant extract at an average daily dose of 11 mg of anthocyanins per 1 kg of body weight (group 3, n=8). Morphometric parameters, glucose tolerance, blood biochemical parameters, antioxidant status, gene expression of enzymes and transcription factors of carbohydrate and lipid metabolism in the liver were studied.

Results: Consumption of HCCDD by the animals (group 2) led to the development of alimentary obesity and fatty hepatosis, increased blood alanine aminotransferase activity, liver paraoxonase-1 activity and glutathione peroxidase gene expression, decrease in glucose tolerance and blood level of free fatty acids, total cholesterol and uric acid, and blood total antioxidant activity, suppression of gene expression of de novo lipogenesis and glycolysis enzymes, membrane glucose transfer proteins in the liver relative to the rats of group 1. Administration of anthocyanins in the 3rd group mitigated negative metabolic effects of HCCDD, was accompanied by normalization of blood level of free fatty acids and total protein, glutathione peroxidase gene expression in the liver.

Conclusion: Inclusion of bilberry and blackcurrant anthocyanins in the HCCDD normalises some indicators of antioxidant status, lipid and protein metabolism without significant effect on body weight and composition, as well as glucose tolerance and severity of fatty hepatosis in rats. The obtained data may be in demand for the development of foods for special dietary uses intended as part of the complex prevention and therapy of obesity.