[Physiological and biochemical in vivo study of polyphenols and 20-hydroxyecdisone from quinoa grains effect on resistance to physical exercise in Wistar rats].

Increasing the ability of the human body to adapt to physical stress is relevant from the standpoint of using foods for special uses containing functional food ingredients (FFI) with effectiveness proven in vivo. The purpose of this study was to evaluate the effect of FFI from Chenopodium quinoa grains with a high content of polyphenols and phytoecdysteroids on the physical endurance of male Wistar rats. Material and methods. The experiment was carried out during 36 days using 50 weaned male Wistar rats. The animals were randomly divided into 3 groups (n=12): Control, Run and Run-FFI. Rats of the Control and Run groups received a standard semisynthetic diet during the experiment. Rats of the Run-FFI group received a semi-synthetic diet with the addition of FFI in an amount of 0.055±0.003%, containing phytoecdysteroids (50.4±0.6 mg/g) and polyphenols (212.0±2.0 mg/g). During the experiment, the rats were assessed for their neuromotor function (grip strength of front paws), memory, and behavioral reactions in the "Elevated Plus Maze" (EPM), "Conditioned Passive Avoidance Reflex" (CPAR) and "Open Field" (OF) tests. Once a week, animals from the Run and Run-FFI groups were subjected to moderate physical load on a "Treadmill". On the 36th day of the experiment, the animals of these groups were subjected to exhausting physical load. Immediately after running, the animals were placed in metabolic cages to collect daily urine. At the end of the experiment, the content of corticosterone, the activity of catalase, indicators of protein, lipid and mineral metabolism, indexes of the liver functional state and antioxidant defense system parameters were analyzed in the blood serum; the level of prostaglandin E2 and dopamine were determined in daily urine. Results. Physiological tests (CRAR, OF) showed that weekly exercise increased anxiety in laboratory animals. The FFI introduction into the diet led to normalization of the assessed parameters (EPM). As a result of 36-day consumption of FFI against the background of physical loads, a significant decrease by 22% in the main stress marker, corticosterone, was revealed in the blood of rats, as well as significant increase by 23% in the stress inhibitor - prostaglandin E2 urinary excretion, compared with animals of the Run group to the level not differed from the indicators of the control animals. There were no differences in endurance performance between the Run and Run-FFI groups on the results of the exhaustive exercise. Consumption of FFI prevented the formation of excess ammonia, significantly reducing the level of urea in the blood and normalizing its excretion to control levels in the urine, which was increased in the Run group by 19%. Conclusion. The results obtained demonstrated the adaptogenic properties of the developed FFI in response to stress caused by weekly moderate and acute exhaustive physical activity. The obtained data on the biological effect of the developed FPI on the adaptive potential of laboratory animals will serve as an experimental basis for its inclusion in the composition of specialized foods.

[Influence of chronic immobilization stress on vitamin status in rats fed different diets].

The influence of a stress factor, widespread in modern conditions, on the vitamin status has not been studied enough. At the same time, the negative stress impact can be aggravated against the background of unhealthy nutrition, which in turn affects the vitamin status of the organism. In this regard, the goal of the research was to evaluate the effect of chronic restrict stress on the vitamin supply in rats fed a diet with adequate and increased content of fat, sugar and cholesterol. Material and methods. The experiment was carried out on 37 growing male Wistar rats (initial body weight of 45±5 g) divided into 4 groups. Animals of the 1st (control) and the 2nd groups received a complete semi-synthetic diet (CSSD) (20% protein, 10% fat, 58% carbohydrates in the form of starch, 384 kcal/100 g) for 92 days. The levels of all vitamins and mineral elements in the rats' diets were adequate for growing rats. Rats of the 3rd and the 4th groups were fed a high-calorie, high-fat high-carbohydrate diet (HFHCD) (20% protein, 28% fat, 2% cholesterol, 18% carbohydrates in the form of starch, 20% sucrose, 511 kcal/100 g). Animals of groups 2 and 4 were subjected to daily 90-minute immobilization. The concentration of vitamins A (retinol and retinol palmitate) and E (α-tocopherol) in the blood serum and liver were determined by high-performance liquid chromatography, vitamins B1 and B2 in the liver and urine, as well as riboflavin in the blood serum and 4-pyridoxic acid (4-PA) in urine were determined by fluorimetric methods. Biochemical parameters of blood serum were determined on a biochemical analyzer; the total content of fat, triglycerides (TG) and cholesterol (CH) was determined in the liver. Results. Replacing CSSD with HFHCD, both under restraint stress and without, was accompanied by an increase in liver weight by 1.8-2.0 fold, in its fat content by 2.6-3.3 fold, cholesterol by 32.6-35.3 fold and TG - by 33.0-57.6 fold (p=<0.001). An increase in alanine aminotransferase (ALT) activity by 1.7-2.0 fold (p=<0.01), in low-density lipoprotein (LDL) cholesterol level by 5.4 fold (p=<0.05) and the atherogenic coefficient by 2.5 fold (p<0.01) as well as a decrease in creatinine and urea level (p=<0.05) in blood serum were revealed. Immobilization was accompanied by a decrease in body weight, liver and liver fat in rats fed both CSSD and HFHCD (p<0.05), but didn't affect the blood serum biochemical parameters, with the exception of an increase in ALT activity. If the activity of alkaline phosphatase (ALP) did not change during immobilization of rats fed the CSSD, then in animals fed the high-calorie diet it decreased by 37.5% (p=<0.05 from the control) under its increase against the background of restrict stress by 78.7% (p=<0.01) compared to the indicator of rats of the 3rd group. Immobilization of rats treated with CSSD was accompanied by an increase in both absolute serum α-tocopherol level and concentration correlated with the level of cholesterol and triglycerides by 26.0-57.5% (p<0.05), with a simultaneous decrease in its content in the liver per 1 g of wet tissue by 22.1% (p=0.041) relative to the indicators of intact animals. Immobilization reduced the level of retinol palmitate in the liver by 2.3 times (p<0.01), but did not affect retinol level in the blood serum. At the same time, indicators of B vitamin status (the content of vitamins B1 and B2 in the liver per 1 g of wet tissue and per organ, blood serum riboflavin level, urinary excretion of riboflavin and 4-PA) did not change, with the exception of thiamine urinary excretion, which reduced compared to the control by 38.8%. In rats fed HFHCD, immobilization had no additional effect on the supply with vitamins A and E. The content of vitamins B1 and B2 in the liver in terms of the whole organ was reduced by 14.0-26.7% relative to the indicator in animals of the 3rd group, not subjected to chronic stress, only due to differences in liver weight in animals of these groups. Conclusion. The data obtained indicate that chronic stress has a negative effect on the vitamin status of the body, worsening the supply with vitamins A, E and B1, and substantiate the feasibility of studying the mechanisms of this effect in order to develop effective vitamin complexes for the treatment and prevention of diseases caused by long-term stress.

The Effect of Semi-Synthetic and High-Fat High-Carbohydrate Diets Containing Cholesterol on Lipid and Cholesterol Metabolism in Male Wistar Rats.

The choice of an optimal biological model of exogenous hypercholesterolemia is necessary for correct assessment of the cholesterol-lowering properties of bioactive substances and specialized food products and for validity of the experimental results. We studied the effects of cholesterol consumption in the composition of the standard semi-synthetic diet and high-fat high-carbohydrate diet for more than 3 months on lipid and cholesterol metabolism in male Wistar rats. Our findings suggest that cholesterol consumption in both diets led to a significant impairment of lipid and cholesterol metabolism, as well as an increase in insulin resistance in rats.

[Modified method for obtaining phycocyanine concentrate of Arthrospira platensis biomass].

The biomass of Arthrospira platensis cyanobacteria is a source of bioactive compounds such as chlorophylls, carotenoids, and, particularly, phycobiliproteins: C-phycocyanin and allophycocyanin. The wide range of biological activity shown by extracts with a high content of phycocyanins determines the prospects for their use as dietary supplements and ingredients of special foods. For food purposes, the degree of purity of phycocyanin concentrates, determined by the ratio of optical densities of their aqueous solutions at two wavelengths, namely D620/D280, must be greater than 0.7. Most methods for obtaining phycocyanin concentrates include laborious steps of fractional ammonium sulphate precipitation of protein from A. platensis biomass extracts followed by removal of salts solution. The use of membrane technology, specifically microfiltration, makes it possible to significantly intensify and simplify the process of obtaining phycocyanin concentrates. The aim of this research was to modify the method for obtaining a high-purity A. platensis phycocyanin concentrate by replacing the stage of ammonium sulfate precipitation of the protein by ultrafiltration of the extract followed by microfiltration. Material and methods. A sample of dry A. platensis biomass was used as a feedstock. Extraction of A. platensis biomass was carried out at a temperature of +40 °C for 3 h, the resulting suspension was centrifuged, and the supernatant was separated from the sediment. The obtained extract was subjected to ultrafiltration (membrane with a pore diameter of 30 kDa) followed by removal of the permeate containing low molecular weight impurities. The retentate was subjected to microfiltration (membrane with a pore size of 0.2 µm), concentrated by reverse osmosis and freeze-dried. Results. The content of C-phycocyanin and allophycocyanin in the dry concentrate was 42.0±1.3 and 7.0±0.3%, respectively, the degree of purity was 1.98. Conclusion. The scheme for obtaining A. platensis phycocyanin concentrate has been modified. A concentrate was obtained with a high degree of purity, allowing its use in food.

[Physiological and biochemical evaluation of the effectiveness of a new food ingredient - blueberry polyphenol concentrate].

Extracts from bilberry leaves and blueberries containing a wide range of biologically active compounds, including polyphenols, are of particular interest due to their antioxidant, hypoglycemic and hypolipidemic properties. In this regard, The aim of this research was to investigate in vivo the effect of a concentrate of blueberrie polyphenolic compounds with buckwheat flour on some physiological and biochemical parameters in C57Bl/6 mice with impaired carbohydrate and lipid metabolism induced by the consumption of a high fat high carbohydrate (HFHC) diet. Material and methods. The polyphenol concentrate was obtained by sorption of blueberry extract on grinded buckwheat flour. Total polyphenol content was determined by Folin-Ciocalteu method, profiles of anthocyanins, flavonoids and easily digested carbohydrates were determined by HPLC. An in vivo experiment was carried out using 84 male mice C57Bl/6 for 109 days. Animals were divided into 3 groups: control fed standard semisynthetic diet, control treated with HFHC diet and experimental group treated with HFHC diet with addition of blueberry polyphenol concentrate (60 mg-eq. of gallic acid/kg body weight). Food intake, body weight gain and fasting blood glucose levels were measured during the experiment. Grip strength of the front paws of the animals was measured weekly. Oral glucose tolerance and insulin resistance tests were carried out twice. Common physiological tests (Elevated Plus Maze and Passive Avoidance Test) were used to assess the anxiety and memory of animals. Glycated hemoglobin level was determined in blood, plasma was collected for leptin and insulin level determination. The hepatic levels of triglycerides and cholesterol were assessed. Results. The concentrate of polyphenols extracted from blueberries and sorbed on grinded buckwheat flour was obtained under conditions that made it possible to exclude the sorption of easily digested carbohydrates - glucose, fructose and sucrose on the flour. The total concentrate content of polyphenols was 65.5±0.7 mg-eq. gallic acid/g, anthocyanins - 27.3±2.7 mg/g, flavonoids - 1.2±0.1 mg/g. The consumption of the concentrate by C57Bl/6 male mice with carbohydrate and lipid metabolism disorders induced by a HFHC diet had a significant (p<0.05) hypoglycemic and hypolipidemic effect, reducing the area under the curve in the insulin resistance test by 5.7% and decreasing the insulin and leptin levels by 31.3 and 15.9%, respectively (relative to the animals of comparison group fed HFHC diet). The consumption of the concentrate had a significant (p<0.05) anxiolytic effect, reducing the anxiety of animals by 2.2 times, as determined in the Elevated Plus Maze test. Conclusion. The results of the study indicate the prospects for using the developed blueberry polyphenol concentrate adsorbed on buckwheat flour as part of specialized foods for the prevention of such alimentary dependent diseases as metabolic syndrome, obesity, and diabetes mellitus.

[Arthrospira platensis: antioxidant, hypoglycemic and hypolipidemic effects in vitro and in vivo (brief review)].

The cyanobacterium Arthrospira platensis biomass is a promising food source of biologically active substances with pharmacological activity. The aim of this research was a brief review and analysis of experimental in vitro and in vivo studies of the antioxidant, hypoglycemic and hypolipidemic properties of A. platensis biomass, phycocyanins, and their chromophore - phycocyanobilin. Material and methods. For the main search of the literature, the PubMed Internet resource was used, the key component of which is the Medline article database, covering about 75% of the world's medical publications. In addition, Scopus and Web of Science databases were used. Search depth - 20 years. Search keywords: Arthrospira platensis, phycobiliprotein, C-phycocyanin, allophycocyanin, hypoglycemic effect, hypolipidemic effect, antioxidant activity, in vitro and in vivo studies. Results. A brief description of the composition of the cyanobacterium Arthrospira platensis biomass, methods of its cultivation, phycocyanins extraction methods is presented. The results of experimental studies indicate the presence of pronounced antioxidant properties of A. platensis biomass, mainly due to phycocyanins in its composition. The hypoglycemic and hypolipidemic effects of A. platensis biomass and extracted phycocyanins intake have been established in vivo when modeling carbohydrate and/or lipid metabolism disorders. The results of in vitro and in vivo studies indicate the presence of pronounced antioxidant properties of phycocyanins. Hypoglycemic effects are shown in particular in experiments on rats with hyperlipidemia and alloxan diabetes fed a diet enriched with A. platensis biomass and on KKAy mice, treated with C-phycocyanin extract. Conclusion. The analysis of the results of in vitro and in vivo studies of the antioxidant, hypoglycemic and hypolipidemic properties of A. platensis biomass and extracts with a high content of phycocyanins, presented in a brief review, suggests that their use in the diet of people with impaired carbohydrate and lipid metabolism is promising. Accordingly, from the standpoint of evidence-based medicine, clinical studies on the use of spirulina biomass and/or its extracts with a high content of phycocyanins as part of specialized foods intended for the prevention and/or dietary correction of carbohydrate and lipid metabolism disorders should be preceded by additional experimental physical-chemical, physiological and biochemical research.

[Amaranth grain proteins: prospects for use in specialized food products].

Amaranth is a widespread genus of predominantly annual herbaceous plants belonging to the Amaranthaceae family, which is one of the most widely used pseudocereals along with quinoa and buckwheat in nutrition. The aim of the research was to review and analyze the results of the studies on the characteristics of amaranth grain proteins, the effect of various food processing methods on their quality, and the prospects for using amaranth protein hydrolysates in therapeutic nutrition. Material and methods. For the main search for the literature, the PubMed bibliographic database was used, which covers about 75% of the world's medical publications. In addition, Scopus and Web of Science databases and non-commercial search engine Google Scholar were used. The depth of the search was 15 years. Results. The paper presents a brief review of modern approaches for obtaining amaranth protein isolates and concentrates, including the use of a complex of physicochemical methods: grinding, sifting, extraction at high pH values, defatting, ultrafiltration, centrifugation, isoelectric precipitation, and drying of the protein product. A comparative characteristic of amino acid content of protein fractions of pseudocereals is presented. Basically, leucine, isoleucine, and valine are limiting amino acids for the grain protein of various varieties of amaranth. When substantiating and developing modern effective food technologies for processing amaranth grain, the studies dedicated to the evaluation of their impact on the biological value of amaranth protein deserve special attention. Methods of grain fermentation, sprouting, steaming, malting, boiling can be used to increase the bioavailability and digestibility of its ingredients. The results of in vitro and in vivo studies indicate the presence of hypotensive, hypolipidemic and antioxidant activity of the amaranth protein and its hydrolysates what determines the prospects for their use as part of foods for special dietary uses and therapeutic nutrition. An analysis of the scientific publications presented in the review indicates an increase in demand for high-quality gluten-free products and an increase in the range of mass-consumption foods, such as bakery, pasta, flour confectionery, with pseudo-cereals in their composition, including amaranth. Conclusion. The high biological value and technological properties of amaranth protein concentrates/isolates determine the prospects for their use to create a wide range of specialized foods for various purposes.

[Arthrospira platensis phycocyanins: a perspective for use in foods for special dietary uses (brief review)].

Biomass of Arthrospira platensis has a long history of consumption as a source of protein, a number of micronutrients and minor biologically active compounds. Specific organoleptic properties of Arthrospira platensis biomass (pronounced bitter taste) limit its use as a source of phycocyanins. The developed modern methods of phycocyanin extraction from A. platensis biomass make it possible to obtain concentrates with improved sensory characteristics destined for the inclusion in foods for special dietary uses. The aim of this brief review was to analyze the results of the studies on the assessment of the biological activity of phycocyanin extracted from the Arthrospira platensis biomass, substantiating the prospects of using their concentrates for inclusion in foods for various dietary purposes. Material and methods. The PubMed Web Database, including MEDLINE article database, covering about 75% of the world's medical publications, was used for the main search for the literature. In addition, Scopus and Web of Science databases were used. Search depth - 15 years. Search keywords: Arthrospira platensis, phycocyanins, safety, antioxidant activity, immunomodulatory properties. Results and discussion. C-phycocyanin and allophycocyanin are complexes of proteins with the pigment phycocyanobilin, their total content is about 50% of the content of all proteins in the A. platensis biomass. A significant number of toxicological studies indicate that there are no risks to human health when using phycocyanin-containing extracts of A. platensis. Evidence of the antioxidant effect of phycocyanins extracted from A. platensis biomass, their anti-inflammatory activity, immunomodulatory properties, was obtained experimentally in vitro and in vivo, as well as in clinical studies. Conclusion. Toxicological studies and experimental in vivo tests have shown the safe and effective use of Arthrospira platensis biomass extracts with a high content of phycocyanins as an additional means of dietary prevention and diet therapy. These data indicate the prospects for conducting additional studies on the possibility of including phycocyanin concentrates in specialized foods for various purposes.