Background: The aim of the present study is to compare the potential of a high-fat diet, a high-carbohydrate diet, and a high-fat, high-carbohydrate diet to induce liver injury and visceral obesity within a period of five weeks, identify the pattern and degree of hepatic changes at the tissue level, identify the earliest metabolic markers of specific liver changes induced by each type of diet, and to test the possible beneficial effects of steviol glycosides in a rat experimental model. Methods: Wistar rats (n = 56) were divided into seven groups as follows: group BD (before diet), group SD (standard diet), group HFD (high-fat diet), group HCHD (high-carbohydrate diet), group HFHCHD (high-fat high-carbohydrate diet), group SDS (standard diet supplemented with Stevia extract), and group HFDS (high-fat diet supplemented with Stevia extract). Results: Total cholesterol concentrations (2.02 ± 0.22 mmol/L) increased in the HFD group (2.56 ± 0.82 mmol/L) and in the HFDS group (2.89 ± 0.48 mmol/L). The VLDL values before diets were 0.27 ± 0.11 mmol/L and increased most significantly in the HFHCHD group—1.14 ± 0.62 mmol/L. The baseline ALT values (88.4 ± 10.6 U/L) increased in the HFD group (128.13 ± 19.5 U/L) and the HFDS group (127.00 ± 17.74 U/L). Similar increases were registered in the AST/ALT ratio and ALP. Total bilirubin (7.10 ± 1.39 μmol/L) increased in HFD group (27.86 ± 17.01 μmol/L). Serum NO had the lowest values in groups fed diets supplemented with steviol glycosides. All high-calorie diets induced hepatocellular injury. The mass of the perirenal fat depot and cross-sectional area of adipocytes were highest in HFD, HFHCHD, and HFDS groups. Conclusion: High-calorie diets have the potential to induce visceral obesity and hepatocellular injury within a very short period of time, which produces characteristic histological changes and specific biochemical profile. Steviol glycosides may alleviate some aspects of the inflammatory response, but findings about lipid profile parameters and liver enzymes are controversial.

PURPOSE: The aim of the study was to evaluate the effects of chronic poloxamer 407 treatment on some parameters of lipid and glucose metabolism in a rat experimental model and to test the potential of this treatment to induce a condition similar to diabetes type 2. METHODS: The following parameters of lipid and glucose metabolism were measured: blood concentration of total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, very low-density lipoprotein (VLDL) cholesterol, triglycerides and glucose concentrations following intravenous glucose tolerance test (IVGTT). Twelve male Wistar rats were used in the study. Rats were divided into two groups: 1) group C (control group) – rats from this group received no treatment during the entire experimental period; 2) group P (poloxamer group) – rats from this group were treated daily with poloxamer for a period of one month after which parameters of lipid and glucose metabolism were measured in both groups. RESULTS: Chronic poloxamer treatment induced significant changes in lipid metabolism parameters but did not affect glucose metabolism parameters. CONCLUSIONS: A 30 days experimental poloxamer treatment in rats is not associated with disorders of blood glucose levels.

PURPOSE: The aim of the study was to evaluate the potential pro-inflammatory effects of different high-calorie diets in a rat experimental model. METHODS: A total of 56 male Wistar rats were included in the experiment. Animals were divided into seven equal groups – one pool group, in which tested indicators were evaluated before the start of the dietary regimens, and six more groups of rats, which were fed different diets for a period of five weeks – standard diet (SD), high-fat diet (HFD), high-carbohydrate diet (HCHD), high-fat high-carbohydrate diet (HFHCHD), standard diet plus E960/RA60 (SDRA) and high-fat diet plus E960/RA60 (HFDRA). Total white blood cell count and differential were measured using an automated analyzer. H2O2 production by blood neutrophils was measured using the nitroblue tetrazolium reduction test on a blood smear. RESULTS: Results demonstrate that some of the high-calorie diets, which contain sucrose, significantly increase H2O2 production by blood neutrophils. CONCLUSIONS: Diets with high content of sucrose may have the potential to induce cellular damage and subsequent inflammatory response in certain tissues.