Olga B. Bekker

Since there is currently no cure for Parkinson’s disease, pharmacobiotic approaches based on gut microbiota—capable of producing pharmacologically active compounds—are under development. In this study, we propose LfU21, derived from the strain Limosilactobacillus fermentum U-21, as a candidate pharmacobiotic. To evaluate its efficacy, a combined LPS- and lactacystin (LAC)-induced Parkinson’s disease model was established in Wistar rats. Effects were assessed using behavioral, biochemical, immunomodulatory, and transcriptomic biomarkers. LfU21 administration reduced α-synuclein levels, altered motor performance in the “Rung ladder” test, and modulated bdnf gene expression in the right and left striata. Under LPS exposure, LfU21 prevented alterations in immune response markers, GSH levels, drd2 and bdnf gene expression, and intestinal goblet cell counts. In LAC and LAC + LPS groups, LfU21 mitigated the rise in α-synuclein, the decline in bdnf expression, and behavioral deficits in the “Open Field” and “Rung ladder” tests, respectively. The multifunctional activity of LfU21 in a combined Parkinson’s disease model underscores its therapeutic potential and helps identify a target patient cohort for future clinical trials.

Since there is no cure for Parkinson's disease yet, pharmacobiotic drugs based on the gut microbiota capable of producing the necessary pharmacologically active compo-nents are being developed. The drug LfU21 based on the strain of Limosilactobacillus fermentum U-21 is proposed as a candidate for pharmacobiotics in this work. To char-acterize the effectiveness of the studied drug, a combined LPS and lactacystin (LAC) induced PD model in the Wistar rat line was used. The analysis was performed using behavioral, biochemical, immune, and transcriptomic biomarkers. LfU21 reduces the level of α-synuclein, changes motor activity in the “Rung ladder” test and the expres-sion of the bdnf gene in both hemispheres of the brain. When exposed to LPS, LfU21 prevents changes in the level of the immune response, GSH, expression of the drd2 and bdnf genes, and the number of goblet cells in the intestine. When exposed to LAC and LAC+LPS, LfU21 prevents an increase in α-synuclein, a decrease in bdnf expression, and indicators in the “Open Field” and “Rung ladder” tests, respectively. The effect of LfU21 in a combined model of Parkinson's disease confirms its multifunctionality. This allows us to determine the cohort of patients for future clinical trials of LfU21.

In 2022, the World Health Organization reported that tuberculosis (TB) was the second leading cause of death globally from a single infectious agent following COVID-19. The development of new antitubercular agents with novel mechanisms of action for use in complex TB therapy is considered a key approach to combating TB. In this study, we examined the gene expression profile of M. smegmatis when exposed to a promising antituberculosis agent, quinoxaline 1,4-dioxide (QdNO) 7-chloro-2-(ethoxycarbonyl)-3-methyl-6-(piperazin-1-yl)quinoxaline-1,4-dioxide-1 (LCTA-3368). We investigated how the bacterial response changed with different minimum inhibitory concentrations (MIC) (1/4 × MIC, 1/2 × MIC, and 1 × MIC) and durations (30 min and 90 min) of treatment with the drug. Our analysis revealed significant upregulation in genes involved in DNA repair and replication processes, as well as changes in the expression of 95 genes encoding proteins with oxidoreductase activity. We additionally showed that the concentration of reactive oxygen species increases in a dose-dependent manner upon exposure of M. smegmatis to LCTA-3368. These findings support the proposed mechanism of antibacterial action of QdNOs, which is associated with the formation of free radicals leading to DNA damage.

In 2022, the World Health Organization reported that tuberculosis (TB) was the second leading cause of death globally from a single infectious agent, following COVID-19. The development of new antitubercular agents with novel mechanisms of action for use in complex TB therapy is considered a key approach to combating TB. In this study, we examined the gene expression profile of M. smegmatis when exposed to a promising antituberculosis agent, quinoxaline 1,4-dioxide (QdNO) 7-chloro-2-(ethoxycarbonyl)-3-methyl-6-(piperazin-1-yl)quinoxaline-1,4-dioxide-1 (LCTA-3368). We investigated how the bacterial response changed with different doses (1/4 × MIC, 1/2 × MIC, and 1 × MIC) and durations (30 minutes and 90 minutes) of treatment with the drug. Our analysis revealed significant upregulation of genes involved in DNA repair and replication processes, as well as changes in the expression of 95 genes encoding proteins with oxidoreductase activity. These findings support the proposed mechanism of antibacterial action of QdNOs, which is associated with the formation of free radicals leading to DNA damage.

The interaction of sodium phytate hydrate C₆H₁₈O₂₄P₆·xNa·yH₂O (phytNa) with Cu(OAc)₂·H₂O and 1,10-phenanthroline (phen) led to the anionic tetranuclear complex [Cu₄(H₂O)₄(phen)₄(phyt)]·2Na⁺·2NH₄⁺·32H₂O (1), the structure of the latter was determined by X-ray diffraction analysis. The phytate 1 is completely deprotonated; six phosphate⁻ fragments (with atoms P1–P6) are characterized by different spatial arrangements relative to the cyclohexane ring (1a5e conformation), which determines two different types of coordination to the complexing agents—P1 and P3, P4, and P6 have monodentate, while P2 and P5 are bidentately bound to Cu²⁺ cations. The molecular structure of the anion complex is stabilized by a set of strong intramolecular hydrogen bonds involving coordinated water molecules. Aromatic systems of phen ligands chelating copper ions participate in strong intramolecular and intermolecular π-π interactions, further contributing to their association. At the supramolecular level, endless stacks are formed, in the voids of which sodium and ammonium cations and water molecules are present. The stability of 1 in the presence of human serum albumin (HSA) was investigated using Electron Paramagnetic Resonance (EPR) spectroscopy. Continuous wave (CW) EPR spectra in water/glycerol frozen solution clearly indicate a presence of an exchange-coupled Cu(II)-Cu(II) dimeric unit, as well as a Cu(II) monomer-like signal arising from spins sufficiently distant from each other, with comparable contributions of two types of signals. In the presence of albumin at a 1:1 ratio (1 to albumin), the EPR spectrum changes significantly, primarily due to the reduced contribution of the S = 1 fraction showing dipole–dipole splitting. The biological activity of 1 in vitro against the non-pathogenic (model for Mycobacterium tuberculosis) strain of Mycolicibacterium smegmatis is comparable to the first-line drug for tuberculosis treatment, rifampicin.

In 2022, the World Health Organization reported that tuberculosis (TB) was the second highest cause of death globally from a single infectious agent, following COVID-19. Development of new antitubercular agents with a novel mechanism of action for use in the complex TB therapy is considered one of the key approaches for fighting TB. In this study we examined the gene expression profile of M. smegmatis when exposed to a promising antituberculosis agent quinoxaline 1,4-dioxide (QdNO) 7-chloro-2-(ethoxycarbonyl)-3-methyl-6-(piperazin-1-yl)quinoxaline-1,4-dioxide-1 (LCTA-3368). We looked at how the bacterial response changed with different doses (1/4 × MIC, 1/2 × MIC, and 1 x MIC) and durations (30 min and 90 min) of treatment with the drug. Our analysis revealed significant upregulation of the expression of genes involved in DNA repair and replication processes, and changes in the expression of 95 genes encoding proteins with oxidoreductase activity. This confirmed the assumption about the mechanism of antibacterial action of QdNOs associated with the formation of free radicals leading to DNA damage.

According to the World Health Organization (WHO), antibiotic resistance is currently one of the most serious threats to human health, food security, and development. Tuberculosis (TB) remains one of the deadliest bacterial diseases. The primary challenge in treating tuberculosis infection is the emergence of strains with multidrug resistance (MDR) to 4-9 drugs. The emergence of bacterial strains with MDR is a consequence of patients’ insufficient adherence to treatment, interrupted therapy, improperly prescribed courses of chemotherapy, and, according to recent data, the accumulation of antibiotics in the environment, which can activate the natural drug resistance system in bacteria. The consequences of MDR to antibiotics include prolonged hospitalizations, increased medical expenses, and mortality. Therefore, the task is to develop new effective antibacterial agents with novel mechanisms to reduce the emergence of bacterial resistance. In this study, we investigated the mechanisms of action of new promising antimycobacterial derivatives of quinoxalin-1,4-dioxide on the model organism Mycobacterium smegmatis .