[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.

[Spinach and quinoa - prospective food sources of biologically active substances].

Formally, phytoadaptogens extracted mainly from medicinal plants are not food substances, and their use in preventive nutrition is significantly limited. However, screening studies can detect phytoadaptogens in food plants, however in much smaller quantities. For example, phytoecdysteroids are biologically active substances (BAS), used to relieve chronic fatigue syndrome, reduce nervous and muscle fatigue, improve memory and attention processes. Phytoecdysteroids can be isolated not only from various medicinal plants, but also from food plants like spinach (Spinacia oleracea) and quinoa (Chenopodium quinoa). Researchers show interest in possible synergies in the manifestation of a wide range of pharmacological effects, determined by a combination of phytoecdysteroids and other biologically active substances of these food plants. The aim of this research is a brief analytical review of publications characterizing the spectrum of minor biologically active substances of spinach and quinoa, as well as those devoted to the experimental assessment of their pharmacological activity in experiments on laboratory animals. Results. An analysis of the publications presented in the review indicates that spinach and its extracts are promising food sources of phytoadaptogens, carotenoids, phenolic compounds, in particular quercetin, kempferol, phenolic acids (p-coumaric, ferulic), as well as lignans metabolized into biologically active phytoestrogens (enterolactone and enterodiol). The possible prophylactic effect of spinach is being actively studied in vivo in laboratory animals when modeling diseases such as diabetes mellitus, cardiovascular and cancer diseases. Numerous adaptogenic effects and the neuroprotective effect of spinach and its extracts are shown, expressed in improving the memory and learning of animals. Publications of the last decade indicate an increased interest in such a promising food source of high-grade protein and a wide spectrum of biologically active substances, including phytoecdysteroids, as quinoa grains. More than 20 phenolic compounds in free or conjugated forms were found in quinoa grains; tannins, saponins, sterols, phytic acid, and ecdysteroids are present in small quantities. The consumptionof quinoa can have a beneficial effect on the organism, normalizing carbohydrate and lipid metabolism, reducing body weight and preventing excessive lipid peroxidation. The anti-inflammatory effects and antioxidant effects of quinoa are widely discussed. Conclusion. Spinach, quinoa and their extracts are promising food sources of biologically active substances, their pharmacological action is confirmed from the standpoint of evidence-based medicine by in vivo experimental studies. Accordingly, it is advisable to expand the use of these food plants for inclusion in biologically active dietary supplements, functional food ingredients and specialized food products for various purposes.

[The impact of bilberry fruits polyphenols, sorbed on buckwheat flour, on the induced disorders of carbohydrate metabolism of male C57BL/6c mice].

The hypoglycemic properties of polyphenolic compounds of plant origin are confirmed by the results of numerous preclinical and clinical studies. However, the biological effects of these compounds are limited by their low bioavailability. This makes it urgent to develop methods for its increasing due to new methods of entering polyphenols into the organism, for example, by extracting them from natural sources in the form of extracts and concentrating extracts on food polymer matrices for subsequent use as a functional food ingredient (FFI). The aim of this study was to evaluate in vivo the possible effect of consumption of the obtained FFI in the form of a food matrix - buckwheat flour enriched with bilberry polyphenols - on carbohydrate metabolism disorders induced by a high-fat diet with a high content of easily digestible carbohydrates (sucrose) and anxiety level of male C57Bl/6c mice. Material and methods. The food matrix was obtained by sorption of the bilberry fruits polyphenol extract on buckwheat flour. The total polyphenol content in the composition of food matrix was 8.9±0.7 mg-eq gallic acid/g flour. Total anthocyanin content in the composition of food matrix was 4.6±0.1 mg/g flour. The experiment was conducted for 150 days using 48 male C57Bl/6c mice (weaners). The animals were divided into 3 groups: the control group K1 (n=16, the mice received a standard semi-synthetic diet (22.5% protein, 10% fat, 58% carbohydrates as starch, 362 kcal/100 g), the control group K2 (n=14) and the experimental group G3 (n=18). Disorders of carbohydrate and lipid metabolism in animals of groups K2 and G3 were modeled by feeding an iso-nitrogenous high-fat diet with a high content of easily digestible carbohydrates (HFHC-diet: 22.5% protein, 30% fat, 18% carbohydrates in the form of starch, 20% sucrose, 493 kcal/100 g). FFI, a food matrix in the amount of 6.6 g/100 g of feed, was introduced into the diet of animals of the experimental group G3, which corresponded to the amount of polyphenols equal to 58.7 mg-eq gallic acid/100 g of feed and the content of anthocyanins 30.4 mg/100 g of feed. Once every three weeks, the level of glucose in the blood of animals was monitored. On days 60 and 114 of the experiment, animals were tested on an elevated plus maze. Animals were decapitated under light ether anesthesia at the end of experiment. The content of glycated hemoglobin was determined in the blood. Results and discussion. Animals of both groups treated with HFHC-diet consumed significantly less feed compared with animals of the control group K1 (2.91±0.05 g/day per mouse). Moreover, animals of the experimental group G3 consumed significantly more food (2.51±0.04 g/day per mouse) compared with animals of the control group K2 (2.36±0.04 g/day per mouse). In contrast, the energy consumption of animals of both groups fed HFHC-diet was significantly higher compared to the K1 group (10.5±0.2 kcal/ day per mouse). Energy consumption by animals of group G3 (12.3±0.2 kcal/day per mouse) was significantly higher compared to animals of the control group K2 (11.5±0.2 kcal/day per mouse). The data obtained indicate that the consumption of FFI in the form of polyphenols adsorbed on the food matrix can contribute to increased appetite in animals treated with the high-fat diet. The results of the Elevated Plus Maze test indicated the absence of the effect of polyphenols in the composition of the food matrix on the anxiety level of animals. Starting from day 42 until the end of the experiment, the glucose level in animals of group G3 was significantly lower than the corresponding indicator for animals of the control group K2. Conclusion. In accordance with the results obtained, further studies of the safety and clinical efficacy of including the developed FFI in the form of a food matrix with polyphenols into the composition of specialized foods for the prevention of carbohydrate metabolism disorders are advisable.

[The complex of bilberry polyphenols, sorbed on the buckwheat flour as a functional food ingredient].

Blueberries, which contain a wide range of polyphenolic compounds, are used in traditional medicine for prevention and treatment of carbohydrate metabolism disorders. However, the high content of mono- and disaccharides in the juice significantly reduces the possibility of using in preventive nutrition by persons with impaired carbohydrate metabolism. In this regard, it is necessary to search for technological approaches aimed at obtaining functional food ingredients with a higher content of polyphenols and a low content of mono- and disaccharides, for subsequent inclusion in corresponding therapeutic foods. The aim of this study was to develop a technological approach to obtain a food matrix by enriching buckwheat flour with polyphenolic compounds extracted from blueberries. Material and methods. The work presents a method for producing a food matrix by sorption of polyphenolic compounds from an aqueous-alcoholic extract of blueberries on buckwheat flour. The concentration of total polyphenols and anthocyanins in the extract and their content in the food matrix was determined by spectrophotometric methods. The content of mono- and disaccharides and profile of individual anthocyanins was determined by HPLC. Results and discussion. The sorption on buckwheat flour was 45% of the total polyphenol content and 48% of anthocyanin content in the initial blueberry fruit extract. The profile of anthocyanins sorbed on a food matrix did not differ significantly from the profile of blueberry extract. The results of determining the content of mono- and disaccharides indicate the absence of their sorption from the extract of blueberries on buckwheat flour. Conclusion. The results obtained are of significant interest, indicating that the sorption approach allows targeted concentration of polyphenols in the food matrix with a minimum amount of easily digestible carbohydrates, which significantly increases the efficiency of its use as a functional food ingredient in dietetic products for people with carbohydrate metabolism disorders.

[Enrichment of the rats diet with docosahexaenoic acid and astaxanthin: physiological and biochemical efficiency].

To investigate the effect of enrichment of the rats diet with polyunsaturated fatty acids (PUFA) ω-3 (220 mg docosahexaenoic acid per 1 kg of animal body weight per day) and astaxanthin (5 mg/kg body weight) on serum corticosterone concentration, physical fatigue, anxiety of rats after exhausting the load. During 30 days the rats of the test group received the diet in which the usual fat component comprising sunflower oil and lard (1:1) was completely replaced by the mixture of oils (high oleic sunflower (89%), coconut (6%), and marine oil from microalgae Schizochytrium sp. (5%) with a high content of docosahexaenoic acid with the addition of astaxanthin). Ratio of ω-6 and ω-3 PUFA in the lipid component of the experimental diet was 5.2:1 (n=12) and 135:1 in the diet of rats in the control group (n=12). DHA enrichment of the diet resulted in a significant 10-fold increase of the DHA liver content and ω-6 PUFA reducing (in particular of linoleic acid in 2.7-fold). No significant differences have been identified between the groups in terms of anxiety, estimated on the elevated plus maze at the beginning and on 24th day of the experiment. Results of the exhausting load on a treadmill (25th day) showed a significant reduction in physical fatigue in rats of the experimental group compared with the control group of rats: the number of contacts with the electrical grid was 4.2±0.9 versus 19.7±4.4, fulltime shock was 0.9±0.2 versus 3.3±0.8 sec. Significantly lower serum corticosterone concentration took place in the subjected to exhausting exertion animals receiving lipid module (15.0±3.9 ng/ml) compared to control animals (31.0±5.4 ng/ml). Thus, modification of the lipid component of the diet by its enrichment with DHA and astaxanthin led to decrease of the rat fatigue during exercise training (test treadmill) and prevent from the serum corticosterone raise, that indicates animal stress adaptation ability.

Interaction of the phage T4 Dam DNA-[N6-adenine] methyltransferase with oligonucleotides containing native or modified (defective) recognition sites.

The DNA-[N 6-adenine]-methyltransferase (Dam MTase) of phage T4 catalyzes methyl group transfer from S-adenosyl-l-methionine (AdoMet) to the N6-position of adenine in the palindromic sequence, GATC. We have used a gel shift assay to monitor complex formation between T4 Dam and various synthetic duplex oligonucleotides, either native or modified/defective. The results are summarized as follows. (i) T4 Dam bound with approximately 100-fold higher affinity to a 20mer specific (GATC-containing) duplex containing the canonical palindromic methylation sequence, GATC, than to a non-specific duplex containing another palindrome, GTAC. (ii) Compared with the unmethylated duplex, the hemimethylated 20mer specific duplex had a slightly increased ( approximately 2-fold) ability to form complexes with T4 Dam. (iii) No stable complex was formed with a synthetic 12mer specific (GATC-containing) duplex, although T4 Dam can methylate it. This indicates that there is no relation between formation of a catalytically competent 12mer-Dam complex and one stable to gel electrophoresis. (iv) Formation of a stable complex did not require that both strands be contiguous or completely complementary. Absence of a single internucleotide phosphate strongly reduced complex formation only when missing between the T and C residues. This suggests that if T4 Dam makes critical contact(s) with a backbone phosphate(s), then the one between T and C is the only likely candidate. Having only one half of the recognition site intact on one strand was sufficient for stable complex formation provided that the 5'G.C base-pairs be present at both ends of the palindromic, GATC. Since absence of either a G or C abolished T4 Dam binding, we conclude that both strands are recognized by T4 Dam.