卷 27, 编号 7 (2024)

Introduction. The development of stimulus-sensitive drug delivery systems ("in situ" systems) is one of the actively developing trends in pharmaceutical technology. First of all, such systems provide sustained and controlled release of the active substance due to a special sol-gel transition. "In situ" systems are solutions that under various physiological conditions transition into a hydrogel. The transition of a solution into a hydrogel depends on various factors such as temperature, pH change, UV radiation, presence of certain molecules or ions. Biopolymers such as chitosan are the basis for in situ systems. Chitosan is an economically available, biodegradable and biocompatible polymer, which makes it a promising raw material for hydrogels. Solutions of chitosan salts are claimed to have stimuli-responsive properties such as pH- and thermosensitivity, however, the composition of such systems usually includes crosslinking agents that may have intrinsic pharmacological and/or toxic activities.

The aim of this study was to test the hypothesis of the thermosensitivity of chitosan lactate-based hydrogels made without crosslinking agents.

Material and Methods. In accordance with the objective, screening experiments were performed to obtain and investigate the properties of chitosan lactate, during which prototypes were obtained to test the ability of hydrogels to thermosensitive transition without auxiliary crosslinking agents and to evaluate the properties of chitosan-based hydrogels at different temperature values.

Results. As a result of the experiments carried out, it was found that the solutions studied are not capable of thermosensitive phase transition. However, it should be noted that during the experiments samples of hydrogels based on chitosan and lactic acid were obtained with different organoleptic and physical properties depending on the concentration of lactic acid.

Conclusions. Based on the results of the screening study, the hypothesis about the thermosensitive transition ability of chitosan lactate solutions without the addition of crosslinking agents was refuted. This issue requires further study using methods that allow to evaluate the underlying changes in the molecular structure of the polymer during gelation when the solution temperature is changed.

The experiments also proved the ability of chitosan to form hydrogels in aqueous solutions with low concentration of weak organic acids with pH in the range from 5 to 6.

Introduction. PSGL-1 is a complex protein, that provides contacts between blood cells and endothelial cells by connecting with cell-adhesion molecules selectins, and it is a universal participant in the processes of leukocyte adhesion, inflammation and immune response. The study of the possible regulation of its functioning is an urgent topic, since the process of its interactions with selectins can be a point of therapeutic application.

Aim of the study. Evaluation of the relationship between the concentration of universal ligand selectins PSGL-1, inducible (iNOS) and endothelial (eNOS) NO synthases and final metabolites of nitric oxide (II) in the blood serum of patients with acute arterial thrombosis.

Material and methods. The concentrations of PSGL-1, iNOS and eNOS in blood serum were determined, using enzyme immunoassay on an enzyme immunoassay analyzer Stat Fax 2100. The total concentration of the final stable metabolites of nitric oxide(II) (nitrates and nitrites) was determined by the spectrophotometric method modified by V.A. Metelskaya, by coloring in the reaction of diazotization with nitrite of sulfonamide present in the composition of the Griss reagent.

The results were processed, using nonparametric statistics methods of Microsoft Office Excel 2016 and IBM SPSS Statistics 26 (StatSoftInc., USA).

Results. The study revealed a statistically significant increase in the level of endothelial nitric oxide synthase and the final stable metabolites of nitric oxide in the blood of patients with acute arterial thrombosis, compared with the control group. A direct correlation of moderate severity was also found between the level of eNOS and the concentration of nitrates and nitrites. A low positive correlation was found between the concentration of PSGL-1 and the level of eNOS, and a low negative correlation was found between PSGL-1 and iNOS.

Conclusions. According to the results of the study, it can be concluded that nitric oxide, which generated by endothelial NO synthase in patients with arterial thrombosis, may have a regulatory effect on the expression or functioning of the universal glycoprotein ligand of selectins – PSGL-1, which requires more in-depth study.

The main goal of this review was to briefly highlight the key points of today’s knowledge about the role and metabolism of vitamin B₂ as well as to compare its status in vegans, vegetarians, and omnivores according to present data. Biologically active forms of water-soluble vitamin B₂ (riboflavin) are represented by flavin mononucleotide (FMN) and flavin adenine diphosphate (FAD), which are coenzymes in the reactions of the electron transport chain and the pyruvate dehydrogenase complex. Riboflavin is also involved in the metabolism of fatty acids, the synthesis of cholesterol and steroid hormones. Riboflavin also participates in the folate cycle. Vitamin B₂ is crucial for the metabolism of other vitamins. FMN is necessary for the formation of the active form of vitamin B₆, while FAD is necessary for the synthesis of niacin. Severe clinical insufficiency of vitamin B₂ is not common. Besides insufficient riboflavin consumption, hypothyroidism can also be a cause of vitamin B₂ deficiency as thyroxine regulates the conversion of riboflavin to its active forms - FMN and FAD. Lack of riboflavin can cause tissue damage; especially of the epithelial, reproductive, and nervous system. The variety of its manifestations is related to the fact that riboflavin deficiency also disrupts the metabolism of vitamins B₆, or PP. Similarly, riboflavin deficiency can also disrupt the folate cycle, increasing the level of homocysteine which damages vascular intima and leads to endothelial dysfunction and atherosclerosis as a result. Rapid urinary excretion of riboflavin makes it safe even if taken in a high dose, changing the urine colour into bright-yellow. This safety of riboflavin makes it unharmful to be used as an oral tracer for monitoring compliance in clinical research. Ultra-high doses of riboflavin (more than 400 mg/day) can cause diarrhoea or polyuria. The content of vitamin B₂ in animal-derived products is higher than in plant-based ones. This also determines its lower intake in vegans and vegetarians compared to omnivores. While there is a shred of evidence that plant-based diets increase the production of bioavailable riboflavin by the gut microbiota, this does not appear to be sufficient to completely compensate for the vegetarians’/vegans’ reduced dietary intake of vitamin B₂, as most of the researches point the fact that vegans and vegetarians are more prone to lack vitamin B₂ than omnivores. At the same time, it should be noted that there exists no universally adopted optimal method for assessing the status of vitamin B₂ in the body. Further research and standardization of methods may ease to assess the prevalence and risks of riboflavin deficiency in various dietary groups.

Introduction. The organs and structures of the oral cavity are among the first to come into contact with the aerosol when using elec- tronic cigarettes and heated-tobacco products, and some of the aerosol components enter various biological fluids of the mouth, inevi- tably provoking a response of the body to external influences. One of the markers of the response are immunoglobulins, and their analysis is intended to help in studying the effect of electronic cigarettes and heated-tobacco products on humans.

Objective. The aim of the study was to estimate changes in immunoglobulins A, G and M of gingival fluid, oral fluid and saliva among users of new types of tobacco products.

Material and methods. The study included 4 groups of 5 people each: regular cigarette smokers, e-cigarette users, users of tobacco heating systems and non-smokers. For laboratory studies, gingival fluid, saliva and oral fluid were taken from the subjects.

Results. Various changes in the concentration of immunoglobulins relative to the control group were observed in all groups of smok- ing patients.

Conclusion. The results may indicate inhibition of the function of local immunity both when exposed to tobacco smoke and when ex- posed to aerosol of heated-tobacco products or electronic cigarettes, which increases the vulnerability of organs and structures of the oral cavity to pathogenic microorganisms.

Introduction. The search for new medicines, including those of plant origin, for the treatment of diseases of the hepatobiliary system is relevant and timely. A promising source for the development of hepatoprotective drugs is golden volodushka (Bupleurum aureum L.). To date, a large evidence base has been accumulated for the biochemical study of this plant, its pharmacological activity has been scientifically proven. Good stocks of golden volodushka in the wild, the simplicity of its harvesting and the possibility of cultivation were noted. The VILAR State Medical University has developed a method for obtaining volodushka golden herb extract of dry.

Aim. The study of the pharmacotherapeutic efficacy of volodushka golden (Bupleurum aureum L.) herb extract of dry in case of liver damage under experimental conditions.

Material and methods. In the studies, white non-linear male rats with a body weight of 180-200 g were used. Volodushka extract was studied at doses of 50 and 100 mg/kg. The comparison drug was silimar at a dose of 100 mg/kg. Experimental CCl₄ – induced hepatitis in rats was caused by a single subcutaneous injection of 50% carbon tetrachloride oil solution one hour after the last administration of the studied extract and the comparison drug. After 48 hours, blood was taken from the tail vein of rats, serum was obtained and its biochemical analysis was carried out. Next, the rats euthanized in a CO₂ chamber and the liver extracted for pathophysiological evaluation. Tetracycline hepatitis was caused by intragastric administration of tetracycline to animals at a dose of 500 mg/kg. Then, after 48 hours, blood was taken from the animals, serum was obtained and its biochemical analysis was carried out.

Results. Volodushka golden grass dry extract on a model of carbon tetrachloride hepatitis exhibits a hepatoprotective effect, which is confirmed by a comparative pathophysiological study and a study of the activity of enzyme markers of the morphofunctional state of the liver in rat blood serum. In the tetracycline hepatitis model, the studied extract also has a hepatoprotective effect, which is confirmed by biochemical studies.

Conclusions. Studies of volodushka extract in conditions of experimental liver lesions have shown that the studied extract in experimental therapeutic doses has a pronounced hepatoprotective effect and is promising for the creation of a herbal medicine for the prevention and treatment of diseases of the digestive system.