Some aspects of the therapeutic effect of catechins are associated with their effect on the deposition of collagen fibrils in tissues. This process is believed to be under the control of the signaling and regulatory systems of cells affected by catechins, but the direct interaction of polyphenols with structural proteins cannot be excluded. In the present work, we investigated the direct effect of (+)-catechin and epigallocatechin gallate on the formation of collagen fibrils in vitro. Using turbidimetry, differential scanning calorimetry, and transmission electron microscopy, we have shown that (+)-catechin accelerates the formation of type I collagen fibrils, with the resulting fibrils having a protein-specific structure and thermal stability, whereas epigallocatechin gallate at a concentration of 10 μM inhibits fibrillogenesis. The obtained results expand our insights into possible mechanisms of therapeutic action of catechins, demonstrating the possibility of direct interaction of (+)-catechin and epigallocatechin gallate with collagen monomers and fibrils, and may be useful in the development of new drugs containing these plant polyphenols or their synthetic analogs.

В работе представлены результаты экспериментального исследования действия флавоноидов разного класса на мембрану липосом из фосфатидилэтаноламина.Методом дифференциальной сканирующей калориметрии определены термодинамические параметры и охарактеризованы термограммы плавления бислойной и небислойной структуры липида в присутствии катехина, кверцетина, дигидрокверцетина, флоретина.Показано, что в интервале температур 15-30 o С кверцетин и дигидрокверцетин вызывают уменьшение высоты перехода на термограммах сканирования липосом и увеличивается энтальпия.Наиболее значительное влияние оказывает флоретин, которое проявляется в снижении энтальпии перехода с 4,39 kcal/mol до 3,52 kcal/mol, при этом полуширина перехода увеличивается почти в 7 раз.Фазовый переход «бислой -гексагональная Н II фаза», в норме наблюдающийся в области 69 o С, в присутствии катехина происходит при температуре 71,7 o С. Существенное изменение вызывает дигидрокверцетин, в присутствии которого энтальпия перехода понижается с 0,49 kcal/mol до 0,32 kcal/mol.Флоретин оказывает слабое влияние на небислойную структуру, в отличие от его действия на бислой мембраны.Предполагается возможность аналогичных изменений фазового состояния липидов в клеточных мембранах при действиях флавоноидов, что может приводить к изменению баланса между липидами.

The work is devoted to the problem of critical situations recognition in real-time and localization of increased acoustic vibration in critical objects, based on the signals from segmental distributed fiber-optic measuring networks (DFOMN). To solve the problem, an architecture is proposed, and a model of a situational approach to using the Convolutional Neural Network as an effective classification method for processing large data arrays of the DFOMN is developed.

The paper presents data on changes in model biomembranes (liposomes, erythrocyte shadows, erythrocytes) used as test objects for determining those areas of concentrations of biologically active substances in which these is no violation of the structure or function of experimental objects. As biologically active substances synthetic ones were selected: plant growth regulator-melafen used in small doses in pre-sowing seed treatment and antioxidant derivatives -phenosan, phenoxan and Ihfans. It was shown by DSC method that phenosan derivatives in concentrations equal to 10 -5 M and more destroy microdomain organization in bilayers of phospholipid multilamellar liposomes and reform protein microdomains in the shadows of erythrocytes. Melafen in small and large concentrations changes polymodally the microdomain organization in the bilayers of phospholipid multilamellar liposomes without destroying the structure and does not affect the protein microdomains in the shadows. Spectral analysis revealed an increase in membrane permeability in isolated whole erythrocytes under the action of melafen in large and small concentrations. The method of small-angle diffraction scattering showed the absence of melafen influence in a wide range of concentrations on the thickness of phospholipid bilayers and the order of their packing in multilamellar liposomes.

Abstract—In the last decade, significant progress has been made in the development of enzyme biosensors, which are used in pharmacology, clinical practice, agriculture, food quality control, monitoring of infectious disease pathogens, and the spread of environmental pollution factors. The functioning of the amperometric multi-enzyme biosensors is based on natural recognition mechanisms. For the best efficiency, the design of the biosensor should enable the analyzed substances to freely interact with enzymes involved in catalytic reactions; this requires knowledge of both the properties of the medium under study and the properties of the analyzed substances. To detect, recognize, and evaluate the concentration of substances in the medium it is also necessary to take factors that can suppress or distort the signal into account, which may be due to the interaction of biosensor components with each other and with molecules of the studied medium. These factors can change not only during storage or after repeated use of a biosensor, but also during a single measurement. Significant progress has been achieved in improving the design of biosensors in the process of development of measuring equipment. This review considers the development of the most interesting and promising trends in the development of amperometric multi-enzyme biosensors that have emerged in recent years.

The paper presents data on changes in model biomembranes (liposomes, erythrocyte shadows, erythrocytes) used as test objects to determine those ranges of concentrations of biologically active substances in which there is no violation of the structure or function of experimental objects. Melaphene, plant growth regulator used in small doses in seed pre-treatment, and antioxidant phenosan derivatives, phenoxane and IHFANs, have been used as biologically active substances. It was shown by DSC that phenosan derivatives at concentrations equal to 10-5 M and higher destroy the microdomain organization in the bilayers of phospholipid multilamellar liposomes and reshape protein microdomains in the shadows of red blood cells. Melaphene in small and large concentrations changes polymodal the microdomain organization in the bilayers of phospholipid multilamellar liposomes without destroying the structure and does not affect the protein microdomains in the shadows. An increase in the membrane permeability in isolated intact erythrocytes in the presence of melaphene in large and small concentrations has been revealed by means of spectral anaslysis. The method of small-angle diffraction scattering showed the absence of the effect of melaphene in a wide range of concentrations on the thickness of phospholipid bilayers and the order of their packaging in multilamellar liposomes.

The influence of phenolic compounds with different numbers of hydroxy groups (phenol, pyrocatechol, resorcinol, and pyrogallol) on the kinetics of in vitro fibrillogenesis of collagen and on fibril structure has been studied. It has been shown that these phenols accelerate fibril formation mainly by shortening the lag phase, presumably facilitating the formation of collagen dimers and their subsequent association to linear aggregates. The accelerating activity of phenols is proportional to the number of hydroxy groups in the molecule. It increases in the series: phenol < resorcinol < pyrogallol. Therefore, the ability of phenols to accelerate fibril formation is likely to stem from the formation of hydrogen bonds with amino-acid residues in collagen chains. The hydrogen bonds may stabilize the structure of the intermediates, facilitating their interaction during fibrillogenesis.

The time course of angiotensin-converting enzyme activity in the rat aorta after fractionated exposure to ionizing radiation and the effects of dihydroquercetin and fucoidin on this parameter were studied. Male Wistar rats were exposed to single or repeated (fractionated) X-ray radiation in a dose of 2.5 Gy at 200 kV. Activity of angiotensin-converting enzyme in aorta segments was evaluated 2 h after the last exposure by hydrolysis of hippuryl-histidineleucin substrate. Enzyme activity in the rat aorta was higher than normally after all the studied doses of fractionated exposure (2.5 Gy per fraction) with the maximum effect after the total dose of 7.5 Gy (3 fractions). Fucoidin, a blocker of endothelium receptors realizing the leukocyte adhesion to the endothelium, and flavonoid dihydroquercetin inhibiting expression of adhesion molecules in the endothelium abolished the increase in activity of angiotensinconverting enzyme in the rat aorta after single exposure; moreover, dihydroquercetin reduced significantly the effect of fractionated exposure. These data indicate that leukocyte adhesion to the endothelium is an important factor contributing to the increase of angiotensin-converting enzyme activity in the aorta.

Excessive physical and mental discomfort, nervous breakdown work stress, inappropriate eating behavior accompanied with disproportionate use of mobile phones lead to various functional disorders and illnesses. Mobile phones, often used by the student community for examinations, social adaptation and self-identification in the future profession, can endanger human health, and might consequently lead to disorders of vegetative regulation of cardiovascular system, including the rising frequency of heart contraction, increase in arterial pressure, muscle and psycho-emotional stress. Holter monitoring based on electrocardiogram (ECG) methodology was used to study the physiological state of the heart within the period of 24 h in students with mobile phones overuse. This monitoring system consists of the MT-101 registry block and MT-200 computer-assisted analyzer. Nine students aged 20-21 years old served the objects of the study. ECG rates recorded in the pre-examination learning process were considered as control, and ECG indicators, recorded during the examination period, were considered as experimental. ECG was studied throughout the day during the learning process and in the examination period to esteem the effects of electromagnetic fields caused by stress situations and mobile phones and identify the frequency of ventricular depolarization (Q, R and S wave or QRS) and heart rate. Both in normal conditions and during the examination period the frequency of heart rate and QRS scores are higher in comparison with the nighttime, at night low values are registered depending on the body's relaxation period. Moreover, it was found that statistical reliability (p<0.05) during the period of examinations increased simultaneously in the nighttime in comparison to control.

One of the most frequently encountered, especially at the adolescents and students, respiratory disease is chronic tonsillitis. It emerges under the influence of infectious agents, such as bacteria, viruses and fungi. The main causes leading to the spread of this disease are changing climate conditions (more often in fall and winter) with increased humidity and cold, when the resistance of body to infection decreases. However, tonsillitis may occur during the summer. In summer, the main causes for the spread of tonsillitis are air recirculating conditioning systems, ice cream, cold drinks, humid and dirty air. 14 students aged 19-23 years old were enrolled into the experiment. divided into two groups by seven students each (with tonsillitis as test and healthy as control). Biologically active points (BAP) symmetrically located to the right and left sides of the human body served as object of the study and were studied by their temperature indicators. Temperature measurements were recorded with "Biotemp-2". The results were statistically calculated. There were no significant differences in the temperature data of points located on the right and left sides of the body in control group; seven points from five meridians were statistically reliant when considering the temperature indices (p<0.05). According to the seven BAP, for which statistical validity was calculated, physiological changes from chronic tonsillitis of these biologically points indicate that they might be used as diagnostic markers.

Changes in BP and HR were assessed after exposures increasing activity of angiotensin-converting enzyme: ionizing radiation, NO synthase inhibitor (L-NAME), and dexamethasone. Effects of dihydroquercetin and angiotensin-converting enzyme inhibitor enalapril on activity of this enzyme, BP, and HR were also evaluated under these exposures. Wistar male rats were subjected to X-ray irradiation in a dose of 2.5 Gy. Angiotensin-converting enzyme activity in the aorta sections was determined by Hip-His-Leu hydrolysis. BP and HR were recorded using a non-invasive tail-cuff method and PowerLab 8/35 software. BP and HR were not altered with the increase in activity of angiotensin-converting enzyme after irradiation. In case of prolonged (7 days) treatment with NO synthase inhibitor and dexamethasone, the increase in enzyme activity was accompanied by elevation of BP and, in the case of NO synthase inhibitor, HR reduction. Dihydroquercetin normalized the enzyme activity and lowered BP, but not to the normal level. Enalapril normalized BP, increased by NO synthase inhibitor solution intake; at the same time, the angiotensinconverting enzyme activity decreased more than 2-fold in comparison with the normal.

The living conditions of certain groups of Kazakhstani population, especially in regions and rural areas, where adverse factors (both environmental and anthropogenic), i.e. the quality of atmospheric air, food, and drinking water are deteriorating, might negatively affect the immune status of inhabitants and lead to the occurrence of diseases. For that reason, the restoration of immunological disorders is an urgent task, since the majority of chronic, somatic, infectious diseases are accompanied by secondary immunological failure. The algorithm of immunomodulation involves the use of pharmacological agents that can increase (immunostimulation) or reduce (immunosuppression) the level of immune response. The chronic toxicity of the immunostimulating "Virospan" drug was studied in doses of 39 mg/kg, 13 mg/kg, 4.3 mg/kg. Intranasal administration of the "Virospan" drug at a dose of 4.5 and 13 mg/kg causes a statistically significant (P <= 0.001) increase in the level of white blood cells, erythrocytes, hemoglobin and hematocrit. Against the background of a statistically significant (P <= 0.001) decrease in the level of polymorphonuclear neutrophils, an increase in lymphocytes was observed. "Virospan" at a concentration of 39 mg/kg leads to a decrease in the total number of leukocytes by 60 days and does not cause pronounced changes in the indicators of red blood, eosinophils and basophils.

We analyzed changes in angiotensin-converting enzyme activity in the aorta of hypertensive SHR rats against the background of age-related BP increase (from week 7 to 14) and the effect of dihydroquercetin on BP rise and angiotensin-converting enzyme activity. Normotensive WKY rats of the same age were used as the control. BP and activity of angiotensin-converting enzyme in the aorta of SHR rats increased with age. Dihydroquercetin in doses of 100 and 300 μg/kg per day had no effect on the increase of these parameters; dihydroquercetin administered to 14-week-old WKY rats in a dose of 300 μg/kg reduced activity of the angiotensin-converting enzyme. Thus, the early (7-14 weeks) increase in BP and angiotensin-converting enzyme activity in the aorta of SHR rats was not modified by flavonoids (dihydroquercetin) in contrast to other rat strains and humans, which is indicative of specificity of hypertension mechanism in SHR rats.

The effects of extracts from the mycelium of Lecanicilium lecaniiNo.169, Beauveria fellina No.7 and Beauveria bassianaNo.15 on the activity of 15-lpoxygenase (15-LO) recovered from rat reticulocytes was investigated. The activity of 15-LO was determined by oxidation of linolic acid. The extract from the mycelium of the fungal complex was shown to inhibit 15-LO (IC50 of 12 mcg/ml). The inhibitory effect of the combined extract on 15-LO was due to the substances recovered from Lecanicilium lecanii No.169. The extract fractions responsible for the activity were determined and the compounds containing the fractions were identified. They proved to be 10 - 4-hydroxybenzoic acid and 4-hydroxybenzyl alcohol and genistein, a flavonoid from fraction 11. The possible role of the inhibitory effect of the compounds on 15-LO in the antiatherosclerotic activity of the fungal extract is discussed.

We studied the interaction with liposomes and the antioxidant activity of flavonoid (quercetin, catechin, taxifolin) complexes with iron(III). It was found that the lipophilicity of complexes depends on an iron:flavonoid ratio and grows at a ratio of 1 to 1, while complexes in a 2: 1 ratio were the most effective to slow down the lipid peroxidation and restore radical 2,2-diphenyl-1-picrylhydrazyl. Thus, the stoichiometry of complexes formed in aqueous solution, may differ from the stoichiometry of complexes that most effectively protect membranes from peroxidation.

Perfluorodecalin increased survival rate of Ehrlich ascites tumor cells under pathological conditions of hypoxia in combination with hyperkalemia. High potassium medium increased the content of lysophospholipids in samples, while in the presence of perfluorodecalin, phosphatidylethanolamine level decreased.

This investigation deals with the structural properties of sarcoplasmic reticulum (SR) membranes. SR is the main Ca2+-pool in the rabbit skeletal muscle. The principal Ca2+-pool functions of the vesicles of fragmented sarcoplasmic reticulum greatly varied depending on the source of the vesicles origin. The heavy vesicles are the fragmented terminal cistern SR, which mainly released Ca2+. The light ones are the fragmented longitudinal tubules SR, which mainly pumped Ca2+. All tested vesicles have some similar and some different structural and functional characteristics that depend on the arrangements of their lipid and protein molecules in the membranes. The lipid-protein relationships were tested with the help of tryptophan fluorescence quenchers.

We studied the influence of heating, ethanol, and sodium azide on the structural and conformational changes in the alcohol oxidase from yeast Hansenula polymorpha. An increase in fluorescence of the alcohol oxidase cofactor, flavine adenine dinucleotide, was revealed upon heating to 60°C while the enzymatic activity of alcohol oxidase was preserved. Differential scanning microcalorimetry revealed that ethanol stabilized the protein structure and increased the melting temperature. Based on the data of circular dichroism, we concluded that the percentage of helicity in the secondary structure of alcohol oxidase was not influenced by ethanol or sodium azide, but ethanol significantly modified the circular dichroism spectrum associated with the tertiary structure of alcohol oxidase.