Biomedical Chemistry: Research and Methods

Comparative Analysis of Bioelectrocatalytic Cytochrome P450 3A4 Systems

P.I. Koroleva — 2024-03-15

This article describes the approaches developed by the authors with the aim to increase the efficiency of electro enzymatic reactions catalyzed by cytochrome P450 3A4. A comparative analysis of cytochrome P450 3A4 systems was carried out during the formation of the functional complexes hemoprotein-flavin nucleotides as low-molecular models of NAD(P)H-dependent cytochrome P450 reductase. The formation of a productive enzyme-substrate complex before the stage ofaccepting electrons from the modified electrode was studied from the electocatalytic viewpoint. Incorporation of the enzyme into nanopores of different nature on the electrode (2D-3D transition) was also studied. The results on the electrochemical reduction of bactosomes as the functionally active models of the microsomal monooxygenase system are also considered. The electrochemical and electrocatalytic parameters of cytochrome P450 3A4 were compared for different models of the electrocatalytic generation of metabolites.

Peroxynitrite Modification as a Way to Improve the Cytocompatibility of Sodium Alginate-Based Hydrogels

A.S. Zakharov — 2024-03-15

Sodium alginate is one of the most frequently used materials in biomedicine. However, alginate-based scaffolds have extremely low adhesive properties and have to be improved. The authors have proposed combined hydrogels of gelatin and sodium alginate which have been modified by peroxynitrite in heterophasic conditions using ethanol. It has been determined that thus modified sodium alginate contains an increased level of carbonyl, carboxyl and nitro groups. Authors have developed chemically and chemical-enzymatically cross-linked hydrogels with better adhesive properties and absence of cytotoxicity. Moreover, sodium alginate modification has a positive impact on cell morphology in comparison with control group of non-adhesive alginate-gelatin hydrogels. It allows the further improvement and application of the biomaterial which have been developed by the authors for bioengineering scaffold production and 3D culturing.

Changes in the Metabolism of Fucose-Containing Biopolymers in Rat Gastrointestinal Tissues under Immobilization Stress

A.V. Oksuzyan — 2024-03-26

The features of fucoglycoprotein metabolism in blood serum and tissues of gastrointestinal tract of rats in the dynamics of experimental stress on 21, 35, 60, 90 days of observation were considered. In blood serum and in homogenates of liver, stomach and small intestine of immobilized rats multidirectional changes in the level of fucose and fucosidase activity were observed. They are manifested by a decrease in the amount of total fucose in blood serum and liver of rats against the background of low activity of the enzyme degrading fucoglycoproteins. The same changes were detected in the tissues of the gastric and small intestine (except on day 35 of the experiment, when the growth of fucose and fucosidase was visualized), which may indicate a change in metabolism toward anabolism. These changes correlate with an increase in the concentration of corticosterone in the blood serum of the rats.

Rifampicin Inhibits TLR4 and IL1β Gene Expression and Enhances SH-SY5Y Cell Viability After Prolonged Ethanol Exposure in an In Vitro Experiment

M.I. Airapetov — 2024-02-09

Prolonged alcohol exposure activates TLR4-signaling pathways in the brain, responsible for the development of neuroinflammation. There is interest in pharmacologic correction of these mechanisms. The antibiotic rifampicin (Rif) is known as a potential neuroprotectant which can correct various pathologic conditions of the nervous system associated with the development of neuroinflammatory events. We performed a study on human neuroblastoma cell culture SH-SY5Y. Prolonged incubation of SH-SY5Y cells with ethanol (24 h, 100 mM) of induced activation the innate immune system genes Tlr4 and Il1β. Pre-treatment with Rif (25-100 mM) prior to incubation of cells with ethanol inhibited Tlr4 and Il1β gene expression, whereas addition of Rif after incubation of cells with ethanol dose-dependently reduced the increased expression of Tlr4 and Il1β genes, with the most significant effect observed at a concentration of 100 mM. In addition, the use of Rif increased cell survival in culture. Thus, the results of our experiment has shown that Rif is able to eliminate the increased expression of inflammation genes caused by prolonged alcohol exposure and to increase the survival rate of long-term incubated cells in ethanol solution.