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Vol 26, No 7 (2023)
Problems of experimental biology and medicine
In silico and in vivo study of the antidiabetic properties of some natural biologically active substances
Abstract
Relevance. According to the Federal Register of Diabetes Mellitus, the number of patients diagnosed with diabetes is 4.9 million people, which is 3.31% of the population of the Russian Federation. The search for new antidiabetic drugs today is still an urgent task of pharmacy. Currently, doctors have a fairly wide range of synthetic drugs in their arsenal, but the issue of rational pharmacotherapy is still open. And in this regard, medicinal products of natural origin look promising.
The aim of the study was to evaluate the theoretical possibility of intermolecular interaction of a number of biologically active substances of plant origin with the active site of non-receptor type 1 tyrosine-protein phosphatase (PTP1B) and the active site of the intestinal maltase-glucoamylase (MGA) enzyme by molecular docking, as well as pharmacological confirmation of specific activity in the experiment.
Material and methods. Male Wistar rats weighing 200–220 grams were used in the study. Modeling of diabetes mellitus was performed by a single intraperitoneal injection of alloxan (150 mg/kg) with a preliminary injection of nicotinamide (250 mg/kg). Animals with a model of diabetes mellitus (n=21) were introduced daily with the original combined substance of plant extracts of Galega officinalis L., Glycyrrhiza glabra L. and Mentha piperita L. at a dose of 500 mg/kg, reference drug - substance gliclazide – 60 mg/kg. The determination of the hypoglycemic effect was carried out after a single introductions and on the 14th day.
Results. The hypoglycemic effect of the phytosubstance was established and the possibility of the influence of biologically active substances on PTP1B and MGA was evaluated. The results of molecular docking indicate a possible interaction of the studied objects with PTP1B and MGA; the highest values of docking are typical for kaempferol, caffeic and ellagic acids. In an in vivo study, a statistically significant decrease in the concentration of glucose in the blood of animals by 49.3% was found.
Conclusions. The possibility of interaction of biologically active substances that are part of plant extracts with specific targets PTP1B and MGA was established by molecular docking, and the hypoglycemic effect of the proposed combined substance of plant extracts of goat's rue, licorice and peppermint was confirmed in the experiment.
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Parameters of oxidative balance and cholesterol metabolism in muscle tissue during prolonged restriction of motor activity
Abstract
Actuality. The leading role in the pathogenesis of metabolic disorders in hypokinesia is performed by disorders of oxidative balance and lipid metabolism. Especially important are studies of metabolic disorders at subcellular level.
The aim of the study is to investigate oxidative balance and cholesterol metabolism in muscle tissue under motor activity restriction of different duration.
Material and methods. Comprehensive investigation of free radical oxidation parameters (diene conjugates, ТBA contents, intensity of chemiluminescence), antioxidant protection (total antioxidant activity, antiradical activity) and cholesterol metabolism in heart muscle and thigh muscle tissues of white male rats under movement restriction during up to 28 days, which was achieved by placing animals in individual 40 cm2 cells.
Results. The patterns of metabolic changes in the muscle tissue depending on the duration of motor activity restriction were established in the form of free radical oxidation intensification, reduction of antioxidant protection resources and increase of cholesterol content in the heart muscle. These metabolic changes were expressed most prominently on the 14th to 21st days of the experiment. In addition to violations of the oxidant balance, a specific feature of changes in cholesterol content in the thigh muscle was a wave-like change of this index in the form of an increase on the 7th day of the experiment, followed by a decrease with minimal values on the 21st day of the experiment.
Conclusion. Decrease in antioxidant protection resources and intensification of free-radical oxidation reactions constitute one of the leading mechanisms of metabolic disturbances in restricting motor activity, which is confirmed by significant changes of the studied indicators. Comprehensive study of the indicators characterizing the processes of free-radical oxidation, antioxidant protection and cholesterol content is an informative criterion of the effects of hypokinesia on the body, and the obtained data allow the inclusion of antioxidants in the complex prevention and therapy in forced limitation of motor activity.
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Pharmaceutical chemistry
Pharmacopoeial methods for the analysis of cardiac glycosides in plant raw materials and medicines (review)
Abstract
The review of modern methods of analysis of cardiac glycosides (CG) offered by pharmacopoeias of Russia, Europe, England, USA, India, Japan and China is presented. The purpose of the review is a comparative analysis of pharmacopoeial methods of identification and quantitative determination of the content of CG in plant raw materials and medicines. It is shown that in the Russian Pharmacopoeia, instrumental methods for the analysis of cardiac glycosides are not widely represented. In this regard, the search for effective methods of analyzing this group of substances in plant raw materials and medicines is relevant.
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Correlation of the component composition of humic acids of peloids with their polymodal action
Abstract
Relevance. The source of humic substances and the method of isolation determines their structure, the specificity of binding of individual fragments, the degree of condensation and conjugation, molecular weights and other characteristics. Humic acids of peloids have a high pharmacological activity due to the presence of various functionals in their composition, which, along with a high molecular weight, allows them to be attributed to the group of polyelectrolytes and determines the universality of the effect.
The aim of the work was to identify the components of humic acid hydrolysate of low-mineralized silt sulfide mud to substantiate their polymodal action.
Material and methods. The object of the study was a solution obtained by extraction into hexane, products of acid hydrolysis of humic acids. The obtained samples were studied using the following methods: chromatography-mass spectrometry (GC-MS) on an Agilent 7890 A chromatograph, IR spectroscopy on a Perkin-Elmer System - 2000 spectrophotometer, elemental quantitative analysis on a Vario EL analyzer.
Results. GC-MS analysis of humic acid hydrolysis products showed the presence of acidic components in the sample and includes both low- and high-molecular fatty monobasic and dibasic acids of saturated unsaturated type. The presence of phenolic derivatives of acrylic acid in the composition causes the inhibitory effect of HA on cell proliferation. The neutral fraction is represented by high-molecular alcohols of natural origin.
Conclusion. Thus, the above components of the hydrolysate justify the currently established and potentially possible effects of humic acids of peloids.
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Synthesis and molecular modeling of thiethane-containing 3-methoxy-4-oxyphenylmethylidenhydrasides 2-[3-methylxanthinyl-8-sulphanil]acetic acids as promising phosphodiesterase 4 inhibitors
Abstract
Objective – to study the parameters of binding of 3-methoxy-4-hydroxyphenylmethylidenehydrazides of 2-[3-methylxanthinyl-8-sulfanyl]-acetic acids with PDE 4A, 4B, 4C, 4D active centers, evaluate the effect of the thietane ring and select the most promising compound for synthesis
Material and methods: The objects of study are phosphodiesterase 4 and the structures of derivatives of thietanylxanthine. The studies were carried out by molecular docking. The structure of the synthesized compounds was confirmed by IR and NMR spectroscopy.
Results and conclusions. The inhibitory activity of 2-[3-methylxanthinyl-8-sulfanyl]acetic acid 3-methoxy-4-hydroxyphenyl-methylidenehydrazides against phosphodiesterases 4 was studied by molecular modeling. It was found that the studied molecules bind in the same site areas as native ligand roflumilast. Binding energies are comparable to roflumilast and for compound II even surpass it. The influence of the thietane and thietane 1-oxide cycles on the inhibitory activity was studied. The most promising compound II was synthesized.
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Determination of the source and selection of the regimen of extraction of Trichoderma Atrobrunneum VKPM F-1434 metabolites with antibiotic activity against representatives of the Enterobactericeae group
Abstract
Relevance. It is relevant to determine the source and select the mode of extraction of biologically active metabolites of the microbial producer in order to further develop the technology for their production.
The purpose of the study. Determination of the source and selection of the mode of extraction of Trichoderma atrobrunneum F-1434 metabolites with antibiotic activity.
Material and methods. The object of the study is a strain of Trichoderma atrobrunneum VKPM F-1434 synthesizing low molecular weight bacteriostatic compounds against Enterobactericeae. The producer was cultured in deep conditions for 5 days, at t – 28 oC, with a sucrose limit of up to 50% of the weight the standard composition of the Chapek medium. The biomass extract and the culture fluid of the producer were purified by centrifugation, the supernatants were examined for antagonism. The active components were isolated by single-stage mixing and settling extraction. The completeness of extraction was determined by varying the volume of the extractant and the time of interaction with the culture fluid. The eluents for thin-layer chromatography were determined by the principal component method. The extract was separated by normal-phase TLC on the stationary phase of Sorbifil, varying the ratio of solvents from 10A:0B to 0A:10B in increments of 1.2x20 cm. Preparatively, the fractions were obtained by column gel-penetrating chromatography with fixed phase Sephadex G-15, particle size 40–120 µm. The mobile phase is dimethyl sulfoxide (DMSO). The molecular weight was calculated from the ratio of the Rf fraction to the Rf of the witnesses.
Results. The maximum sensitivity of the test culture is shown in an experiment with a culture fluid preparation. The most available extractants for the extraction of metabolites were ethyl acetate and butanol. The greatest value of the completeness of extraction is achieved when equal volumes of extractant and culture fluid interact for 180 minutes. The optimal mobile phases were determined by the principal component method: I – hexane : chloroform; II – hexane : acetone; III – hexane : acetone : methanol (10%). Three fractions were isolated, bacteriostatic activity was determined for each, the Rf was calculated and the molecular weights, as well as the coefficients of antibiotic activity, were theoretically calculated.
Conclusions. The components of the culture liquid T. atrobrunneum VKPM F-1434, having bacteriostatic activity, can be extracted by stirring for three hours equal volumes of ethyl acetate and culture liquid, and determined in the extract using TLC on silica gel with impregnated methanol in the system of hexane and DMSO – 6:4 eluents.
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Study of the effect of modification of the structure of a new derivative of quinazoline–4(3h)–one on fatty acid synthase (FAS) Mycobacterium
Abstract
Relevance. Tuberculosis remains one of the main causes of disability and mortality from infectious diseases worldwide. The discovery of phenotypically tolerant subpopulations of pathogen persisters has called into question the possibilities of known anti-tuberculosis drugs. In this connection, the search and development of new effective anti-tuberculosis drugs is an important direction in the development of modern pharmacology. Currently, it is relevant to consider substances of the quinazoline nature as antimicrobial agents that exhibit antitubercular activity.
The aim of the work is computer modeling of the interaction of new derivatives of quinazoline–4(3H)–oh with NAD(H) in order to predict the possibility of influencing the fatty acid synthase (FAS) Mycobacterium.
Material and methods. Modeling of intermolecular complexes in the interaction system of new derivatives of quinazoline-4(3H)–on – VMA–17–04 and VMA–13–05 with the oxidized form of NAD+ was carried out using the quantum chemical semi-empirical PM7 method implemented in the MOPAC 2016 program.
Conclusions. The VMA–13–05 derivative, being in stable conformation I, forms an adduct with NAD+ having optimal energy characteristics. This interaction can be considered as one of the stages of the biochemical pathway of suppressing the activity of FAS synthase, which takes part in the synthesis of mycolic acids and leads to the death of Mycobacterium cells.
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Identification and quantitation of fexofenadine hydrochloride in model oral drops
Abstract
Relevance. Fexofenadine hydrochloride is a representative of the III generation of histamine H1 receptor blockers, therefore, it is not characterized by the disadvantages of antihistamines, such as: suppression of the central nervous system, cardiotoxic effect, headache, impaired coordination of movements, photosensitivity. Analysis of fexofenadine hydrochloride was performed using UV spectroscopy.
The purpose of the study – development of a new analytical method for the qualitative and quantitative identification of fixofenadine in drops for internal use.
Material and methods. The study used: fexofenadine, sodium hydroxide, water for injection, UV spectrophotometer type SF-104.
Results and conclusions. A method for the qualitative and quantitative determination of fexofenadine hydrochloride in model drops for internal use by the SPS method has been proposed. This method meets the requirements of OFS 1.1.0012.15 Validation of analytical methods, in terms of indicators: linearity and analytical area, correctness, precision.
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