Metabolic syndrome is an epidemic of non-infectious origin, which is associated with the consumption of a large amount of high-calorie food and a sedentary lifestyle. It is not excluded that bacterial lipopolysaccharides (LPS) may enter the body during metabolic syndrome. The purpose of this work is to study the combined effect of bacterial lipopolysaccharide and high fructose diet on the concentration of glycosaminoglycans and their individual fractions, the content of free L-oxyproline and sialic acids in rat biceps femoris muscle. Bacterial LPS was injected intraperitoneally at a dose of 0.4 μg/kg. Metabolic syndrome was modelled by using 20% fructose solution as only source of drinking water. In the test group of animals total concentration of glycosaminoglycans increased by 22.53%, the heparin-heparan and keratan-dermatan fraction concentrations raised by 26.18 and 35.91%, but concentration of the chondroitin fraction did not change compared to the control. The concentrations of free L-oxyproline and sialic acids increased by 120.71 and 156.78%, respectively. Thus, high fructose diet, stimulation of the organism with bacterial lipopolysaccharide and their combination lead to increased degradation of glycoproteins and proteoglycans and intensify collagenolysis in the biceps femoris muscle of rats.

Metabolic syndrome is one of the most widespread non-infectious pathologies in the world. Metabolic syndrome is quite often accompanied by an increase in body weight and can lead to the development of type 2 diabetes. Between 1990 and 2015, global mortality associated with high body mass index increased by 28.3%. The purpose of this work is to determine the activity of antioxidant enzymes, the production of superoxide anion radical, the content of oxidatively modified proteins and the concentration of malondialdehyde in the biceps femoris of rats under experimental metabolic syndrome and stimulation of the organism with bacterial lipopolysaccharide. The study was conducted on 24 sexually mature male Wistar rats weighing 200-260 g. The animals were divided into 4 groups of 6 animals each. The first group was the control group. The second group was the test metabolic syndrome group. Metabolic syndrome was modelled by using a 20% fructose solution as the only source of water for 60 days. The third group received S. typhi bacterial lipopolysaccharide in the first week in a dose of 0.4 μg/kg intraperitonealy three times a week, then once a week throughout the experiment. The fourth group underwent the combined exposure to lipopolysaccharide and metabolic syndrome. The development of oxidative stress was observed in the three experimental groups. During modelling of the metabolic syndrome, oxidative stress was characterized by an increase in the production of the superoxide anion radical whilst the activity of the studied antioxidant enzymes decreased. During bacterial lipopolysaccharide stimulation, oxidative stress was characterized by an increase in the production of superoxide anion radical under an increase in superoxide dismutase activity and a decrease in catalase activity. Combined stimulation of the organism by bacterial lipopolysaccharide and modelled metabolic syndrome on the oxidative stress was characterized by an increase in the production of the superoxide anion radical under an increase in the activity of the studied antioxidant enzymes. The combined stimulation by bacterial lipopolysaccharide and modelled metabolic syndrome leads to the development of oxidative damage to the lipid and protein components of biceps femoris that is a consequence of an increase in the production of reactive oxygen species under a compensatory increase in the activity of antioxidant enzymes.