We obtained red wine concentrate, which was enriched with natural polyphenolic compounds (PC concentrate). The main purpose was to study the hypoglycemic and antioxidant effects of the red wine concentrate, and its impact on key hematological parameters of rats with experimental diabetes mellitus. While administrating the red wine concentrate to rats with diabetes, partial recovering of glucose tolerance was promoted, as well as normalization of glycated hemoglobin level, an increase in the quantity of erythrocytes and hemoglobin concentration. PC concentrate had anti-radical effect, which was determined using 2,2-diphenyl-1-picrylhydrazylradical (DPPH) method and effectively inhibited oxidation of phosphatidylcholine liposomes, induced by 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) as a free radical generator. It was also confirmed that PC concentrate had antioxidant properties in vivo. The contents of lipid peroxidation and protein oxidation products, the activity of catalase, and glutathione peroxidase (GPx) were increased in the plasma of rats with diabetes mellitus. At the same time, the activity of superoxide dismutase (SOD) was decreased. The concentrate of red wine had a corrective effect on investigated indicators and caused their normalization in plasma of diabetic animals.

Changes in immunocompetent cells influence the course of diabetes mellitus and contribute to its complications. Thus, correction of diabetes-induced immune system disorders is vital for normalizing the state of the organism. Red wine polyphenols due to their biological activities could be considered a potential remedy for correcting diabetes. The study aimed to evaluate the antimicrobial potential and the influence of red wine polyphenols on immune system in streptozotocin-induced diabetes. We studied immunological parameters, i.e. quantity of white blood cells in peripheral blood and peritoneal macrophages, the bactericidal activity of phagocytes of blood, the activity of myeloperoxidase, and the level of cationic proteins in these cells after the administration of the polyphenol-rich red wine concentrate (PC concentrate) of known composition, obtained from Ukrainian wine, for 14th day to rats with streptozotocin-induced diabetes. The Minimal Bactericidal Concentration (MBC) of the PC concentrate was determined with the Broth Microdilution method. The PC concentrate normalized the quantity and functional activity of peripheral blood neutrophils and peritoneal macrophages, and decreased the quantity of lymphocytes under diabetes, as well as possessed the antibacterial activity against Staphylococcus aureus and Escherichia coli. Our results indicate the significant biological potential of the PC concentrate and its therapeutic relevance to correct diabetes-induced disorders.

Background. The positive health effects of polyphenols have led to an increased scientific interest in these natural compounds over the past decade. Many studies confirm the effectiveness of polyphenols as additional therapy in diabetes, especially due to the sugar-lowering effect of polyphenols. The aim of the research was to investigate the morphological and functional state of peripheral blood erythrocytes and the indices of oxidative stress in the liver of rats with experimental diabetes and after the administration of grape pomace extract rich in natural complex of polyphenols. Materials and Methods. We obtained grape pomace extract, which contains a variety of polyphenolic compounds. Rats of the following groups were used in the experiments: control animals, animals treated with grape pomace extract rich in natural complex of polyphenols for 14 days, animals with streptozotocin-induced diabetes mellitus, and animals with streptozotocin-induced diabetes mellitus treated with grape pomace extract rich in natural complex of polyphenols for 14 days. The number of erythrocytes and reticulocytes, the concentration of hemoglobin and glycated hemoglobin were determined in the peripheral blood of rats. The activities of catalase, superoxide dismutase and the content of thiobarbituric acid-reactive substance and carbonyl groups of proteins were determined in the liver tissues of rats. Results. The study has shown an increase in the number of erythrocytes and the level of hemoglobin, a decrease in the level of glycated hemoglobin and the number of reticulocytes in the peripheral blood of rats after administration of grape pomace extract rich in natural complex of polyphenols to rats with experimental diabetes. A decrease in the content of thiobarbituric acid-reactive substance and the content of carbonyl groups of proteins of neutral and basic character and an increase in the activity of catalase and superoxide dismutase in liver tissues were found under the same conditions. Conclusions. The results indicate that the extract of the natural complex of polyphenols is capable of correcting the morphological and functional state of erythrocytes, as well as improving the activity of antioxidant enzymes and the content of marker molecules of oxidative stress in hepatocytes of rats under experimental diabetes mellitus.

Background. Diabetes mellitus is accompanied by oxidative-nitrative stress, which is caused both by an increased generation of the Reactive Oxygen Species and the Reactive Nitrogen Species under the conditions of this pathology and by the disorders of the antioxidant defense system, especially its enzymatic part. This leads alterations in the morpho-functional state of cells, organs, and the whole organism. Free radicals are involved in the destruction of pancreatic cells in type 1 diabetes mellitus, which leads to even greater inhibition of insulin secretion, worsening of the course of the disease and occurrence of diabetic complications. The complications of diabetes mellitus include often diagnosed cardiovascular diseases. Therefore, the use of treatments characterized not only by hypoglycemic properties for normalization of blood sugar level in diabetes mellitus, but also by antioxidant properties for normalization of oxidative/antioxidant balance of the organism in the studied pathology can be promising. Scientists pay a great attention to the study of substances with such properties, especially natural phenolic compounds of grape, which are also characterized by immunomodulatory properties. Materials and Methods. The study was performed on cardiac tissues of control rats, control animals treated with wine polyphenolic complex concentrate, animals with streptozotocin-induced diabetes mellitus and animals with experimental diabetes mellitus treated with a concentrate of wine polyphenolic complex. The activity of catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase were detected to examine the corrective effect of the concentrate of red wine natural polyphenolic comp­lex on the state of the enzymatic part of the antioxidant defense system. Results. The results have shown the normalization of activity of catalase, superoxide dismutase, and changes in the activity of enzymes of glutathione cycle after oral administration of polyphenolic complex concentrate for 14 days to rats with streptozo­tocin-induced diabetes mellitus. Conclusions. The results confirm a hypothesis about the antioxidant effect of the studied concentrate and the ability of natural polyphenolic complexes to serve as the basis for new drugs for treatment of diabetes-induced disorders.

Grape pomace, a polyphenol-rich byproduct of wine production, represents a promising source of bioactive compounds for managing diabetes and its complications. This study evaluates the effect of a novel grape pomace extract on carbohydrate and lipid metabolism, and oxidative stress in type 1 diabetes mellitus. Diabetes was induced in male Wistar rats by a single intraperitoneal injection of streptozotocin. Starting on day 14 post-induction, rats received oral grape pomace extract at a dose of 45 mg of polyphenols/kg body weight daily for 14 days. On day 28 of the experiment, blood plasma was collected. One-way ANOVA with post hoc testing revealed a hypoglycemic effect of grape pomace extract, as evidenced by reduced fasting blood glucose and improved postprandial glycemic responses. The extract also ameliorated dyslipidemia, lowering total cholesterol and triglycerides while increasing high-density lipoprotein levels and paraoxonase activity in plasma of diabetic rats. Antioxidant defenses were enhanced, as indicated by elevated superoxide dismutase, catalase, and glutathione peroxidase activities, along with reduced protein carbonyls, TBA-reactive products, and lipofuscin in blood plasma following extract administration. These findings demonstrate the metabolic and antioxidant potential of grape pomace polyphenols, although further investigations are needed to elucidate the underlying molecular mechanisms.

Background. Diabetes mellitus is one of the most common diseases in the world. Under this pathology all organs and systems of an organism are damaged, inclu­ding the immune system. Peripheral blood leukocytes are an important element of this system that suffer damage under diabetes mellitus due to the influence of reactive oxygen species and reactive nitrogen species, the number of which increases fast and leads to the development of oxidative-nitrative stress. Thus, the discovery of new diabetes-correcting drugs that possess hypoglycemic, antioxidant and immunomodulatory proper­ties is one of the principal tasks. Such properties are inherent in polyphenolic compounds, a large amount of which is contained in the grape pomace. That is why the study of grape pomace extract, rich in a natural complex of polyphenols, is important to evaluate the possibility of further use of these substances as a basis for drugs that can be used in the complex therapy of diabetes mellitus. Materials and Methods. The research used peripheral blood leukocytes of the control rats, the control animals that were treated with grape pomace extract for 14 days, animals with streptozotocin-induced diabetes mellitus and rats with experimental diabetes mellitus that were treated with grape pomace extract for 14 days. To evaluate the corrective effect of the grape pomace extract rich in a natural complex of polyphenols on the state of the antioxidant defense and the L-arginine/NO systems, the activity of antioxidant enzymes, the level of oxidative modification products of proteins and lipids, the activity of NO-synthase, the content of nitrites and nitrates, 3ʹ-nitrotyrosine-modified proteins were studied. The total number of leukocytes, the white blood cell differential and the phagocytic activity, and the average cytochemical coefficients of cationic proteins and NADPH-oxidase activity were indicated to study the effect of the grape pomace extract on the functional state of leukocytes. Results and Discussion. The study revealed normalization of the total number of leukocytes and the white blood cell differential, the activity of NADPH-oxidase, superoxide dismutase, catalase and glutathione peroxidase, and the levels of the oxidative modification products of proteins and lipids, nitrites, nitrates and 3ʹ-nitrotyrosine-modified proteins, as well as an increase in the average cytochemical coefficient of cationic proteins, and a decrease of the inducible NO-synthase activity after grape pomace extract administration for 14 days to animals with streptozotocin-induced diabetes mellitus. Conclusion. The obtained results confirm the antioxidant and immunomodulatory effects of the studied extract and justify the feasibility of using grape pomace complex of polyphenolic compounds as a basis for new drugs that will be used in the complex therapy of diabetes mellitus.