Vol 28, No 2 (2025)

Monoamine oxidase (MAO) is an FAD-dependent enzyme essential for regulating neurotransmitter levels and protecting the body from the harmful effects of amines. Dysregulated MAO activity, through either overexpression or excessive activation, has been linked to diverse pathological conditions. Emerging evidence highlights MAO as a key contributor to oxidative stress, driving significant damage not only to the nervous system but also to the cardiovascular system. Additionally, MAO is implicated in tumor progression and metastasis. Targeting MAO through chemical inhibition offers promising therapeutic avenues for treating neurodegenerative disorders, cancer, heart failure, rheumatoid arthritis, multiple sclerosis, and other inflammatory diseases. Potential applications also extend to addressing migraines, dizziness, attention deficit disorders, diabetes, obesity, muscular dystrophy, and metabolic dysfunctions. This review summarizes current methodologies for assessing MAO activity and inhibition, alongside in vivo models used to study neurodegenerative diseases, providing a foundation for future therapeutic strategies.

Introduction. Phlojodicarpus sibiricus is a valuable plant raw material – a source of coumarins, on the basis of which effective dosage forms (dry extracts, tinctures) for the treatment of neurodegenerative diseases have been created. The chemical composition of the plant is well studied, but there is no information about the composition of amino acids in both aboveground and underground parts of plants.

The aim of the study is to determine amino acid composition and their content in the herbs, roots and rhizomes of Phlojodicarpus sibiricus from different habitats.

Material and methods. The object of the study are herbs, roots and rhizomes of Phlojodicarpus sibiricus, collected in 2020, 2022, and 2023 during the fruiting phase from different populations in the Republic of Buryatia and Trans-Baikal Territory. Analytical samples were obtained by the quartering method. The amino acid composition and content were determined according Russian National Standard R 55569-2013 using the capillary electrophoresis system "Kapel-105".

Results. 20 amino acids have been found in grass and rhizomes and roots, of which 8 are essential. The total content of 20 amino acids in the underground organs of plants was in the range of 31,62–48,80 mg/g of dry weight, of which the share of essential acids accounted for an average of up to 23% (about 39 mg/g). In the herb, these values were up to 2,5 times higher than in the rhizomes and roots.

Conclusion. In this regard, we have studied for the first time the composition and amino acid content of grass, rhizomes and roots of Siberian bulbous fruit from different populations of the Republic of Buryatia and the Trans-Baikal region. The obtained results supplement the existing information on the chemical composition of valuable raw materials and can be used in the future for development of medicines and biologically active suplements based on Phlojodicarpus sibiricus.

Introduction. The development of postCOVID syndrome is accompanied by changes in one-carbon metabolism and the development of cardiovascular diseases in patients who have undergone a new coronavirus infection. To understand the pathogenesis of postCOVID syndrome in patients with cardiological pathology, it is important to study possible biochemical changes, as well as to search for predictors to assess the risk of cardiovascular pathology.

Objective – to evaluate changes in homocysteine and folic acid levels at different times after a new coronavirus infection in patients with cardiovascular diseases.

Material and Methods. The case-control study included 82 patients of the cardiology department, of which 49 patients at different times after COVID-19 (6 months, 12 months and 24 months) and 33 patients without a history of COVID-19 (control). Serum concentrations of homocysteine and folic acid were determined in all patients.

Results. In cardiac patients with COVID-19, regardless of the prescription period, the concentration of homocysteine was 11.1 [9.3; 14.2] mmol/l, in the control – 13.9 [12.0; 16.9] mmol/l (p=0.013). At the same time, the folic acid content in the group of patients who underwent Covid-19 was statistically significantly lower than in the group of patients who did not have COVID-19 (6.52 [4.26; 8.86] and 11.0 [8.08; 12.3] ng/ml, respectively). When analyzing homocysteine levels depending on the prescription period after COVID-19, after 6 months, the homocysteine level was 9.4 [8.3; 13.7] mmol/l, after 12 months – 10.3 [9.2; 10.6] mmol/l, after 24 months – 13.2 [11.2; 17.2] mmol/l, p=0.004. The concentration of folic acid in patients 6 months after COVID-19 was 6.13 [3.36; 8.68] ng/ml, after 12 months – 10.1 [5.63; 16.1] ng/ml, after 24 months – 5.82 [5.44; 8.06] ng/ml, p=0.08. At the time 24 months after the COVID-19, the homocysteine/folic acid ratio was higher than at other times, indicating an imbalance in one-carbon metabolism.

Conclusion. Hyperhomocysteinemia is observed in patients with cardiovascular pathology, regardless of the coronavirus infection. After COVID-19 in patients with a cardiological profile, disorders in single-carbon metabolism, manifested by folic acid deficiency and hyperhomocystenemia, underlie the development of long COVID and are predictors of cardiovascular complications.

Rabies remains one of the most important problems in the world, especially in Asia and Africa, where up to 60,000 people die annually. The situation of rabies morbidity in Russian Federation for the period 2012-2022 is characterised by downward trend due to preventive measures carried out among animals and timely post-exposure immunisation of people.

The issues of rabies control, caused by the virus of the genus Lyssavirus of the family Rhabdoviridae, infection with which leads to 100% mortality in the absence of post-exposure immunoprophylaxis, are considered. Post-exposure measures, including the use of anti-rabies immunoglobulin and vaccination, are of particular importance. Administration of antirabic immunoglobulin provides the creation of passive immunity, preventing the spread of the virus before the beginning of antibody production in response to the introduction of an antirabic vaccine.

The search for promising directions in the creation of new-generation drugs for passive immunoprophylaxis of rabies is topical. As an alternative to traditional immunoglobulin, the use of monoclonal antibodies (mAbs) with high affinity to the rabies virus glycoprotein is proposed. WHO recommends the use of ‘cocktails’ of two or more mAbs, which is due to the diversity of target epitopes in rabies virus strains and the possibility of uncontrolled point/local mutations in the antigenic sites of the virus.

The need to optimise the production and quality control of heterologous anti-rabies immunoglobulin by expanding the list of controlled indicators and methods of their determination, including for the purpose of harmonisation with the requirements of the Eurasian Economic Union (EAEU) decisions for the formation of a common market of medicines has been shown.

Thus, research into the development of new anti-rabies drugs should be continued in order to improve the effectiveness of rabies control measures and reduce lethality. At the same time, it remains important to optimise the production and quality control of existing drugs that have proven their effectiveness.

Introduction. When using immunochromatographic test strips for preliminary urine tests of examined persons for the fact of using psychoactive substances, there is a possibility of false positive results. One of the possible approaches to solving the problem of false positive results of chemical and toxicological studies, including cross-reactions in the drug administration, is hair analysis.

The purpose of this work is to study the timing of detection of certain drugs (mebeverine, phenylephrine, sertraline, chlorpromazine) in urine and hair to exclude unreliable results of clinical laboratory diagnostics.

Material and methods. Modeling of drug administration (phenylephrine, mebeverine, sertraline, aminazine) was carried out using laboratory animals - guinea pigs. The study of extracts from biological objects was carried out on a gas chromatograph with a mass-selective detector Agilent Technologies (USA) 7890 A/5977 MSD, as well as by the HPLC-MS/MS method on a modular liquid chromatograph Nexera XR with a tandem mass spectrometer LCMS-8050 (Shimadzu, Japan).

Results. The dynamics of the content of the studied medicinal substances in the urine within 168 hours after a single dose of daily dosage, the maximum detection time of these substances: mebeverine and chlorpromazine for more than 7 days, sertraline and phenylephrine for no more than 5 days were studied. The features of the accumulation of the studied medicinal substances in the hair are determined. Mebeverine and chlorpromazine accumulate in significant amounts in the hair when ingested chronically, about 100 ng/mg and 80 ng/mg, respectively, and are also identified in statistically significant amounts 56 days after chronic use is stopped. Phenylephrine and sertraline accumulate in the hair in trace amounts, at a level of 2-5 ng/mg, and are also detected in trace amounts 28 days after discontinuation of administration.

Conclusion. A systematic study of the dynamics and level of accumulation of toxicants in the hair tissue on the example of the studied drugs (mebeverine, phenylephrine, sertraline and chlorpromazine) showed results consistent with the data of the literature, and indicating that the dynamics of the accumulation and the level of accumulation of drugs in the hair structure depends on the physicochemical and pharmacological properties of the substance itself. Studies have shown that substances accumulate in the hair structure only in the form of native molecules, which makes it possible to recommend this biological material to solve the issue of cross-reactions of medicinal substances during the preliminary stage of clinical laboratory diagnostics with immunochromatographic test strips.