In vitro Antimicrobial Activity Profile of Modified Pyrimidine Nucleosides Derivatives

Background: The increase in prevalence of antimicrobial-resistant bacteria (ARB) is currently a serious threat, thus there is a need for new classes antimicrobial compounds to combat infections caused by these ARB. The growth inhibition ability of derivatives of the components of nucleic acids has been well-characterized but not for its antimicrobial characteristics. Aims: To evaluate in vitro antimicrobial activity profile of modified pyrimidine nucleosides derivatives. Methodology: Modified nucleosides arabinofuranosylcytosine (cytarabine, ara-C), [1-(2',3',5'-tri-O-acetyl-β-D-ribofuranosyl)-4-(1,2,4-triazol-1-yl)]uracil (TTU), and nucleotides cytarabine-5′-monophosphate (ara-CMP), and O2,2′-cyclocytidine-5′-monophosphate (cyclocytidine monophosphate, cyclo-CMP) were synthetized and subsequentially checked for antibacterial activity. Bacterial cells characteristics were assessed by antiproliferative and the production of intracellular reactive oxygen species (ROS) assays. Results: It was found that modified nucleosides ara-C, and TTU, and nucleotides ara-CMP, and cyclo-CMP were able to inhibit Escherichia coli, Sarcina lutea, Bacillus cereus, and Proteus mirabilis strains in a time and dose dependent manner via killing kinetics assay. Gram-negative (E. coli and P. mirabilis) bacteria stains were more sensitive to the exposure of TTU and cyclo-CMP and less sensitive to the exposure of ara-C and ara-CMP compared to gram-positive ones. The most effective cells growth inhibitor for gram-positive strains (S. lutea, B. cereus) was ara-CMP with ED50 = 5.2•10-5 M and 3.1•10-4 M, respectively. Sarcina lutea appeared to be the most sensitive bacteria strain to the exposure of all studied compounds. It was demonstrated that studied modified pyrimidine nucleosides derivatives enhanced the production of intracellular ROS over time (validated via DCFA-DA probe assay). Conclusion: This study has revealed the mechanism of action of cytarabine, cyclocytidine monophosphate, and TTU as an antimicrobial agent for the first time, and has shown that these pyrimidine derivatives enhanced might be able to combat infections caused by Escherichia coli, Sarcina lutea, Bacillus cereus, and Proteus mirabilis in the future.

Improving Diagnostic and Eliminating Techniques of Bovine Leukemia in the Russian Federation

Leukemia occupies a leading place in the structure of infectious diseases of cattle, as it causes significant economic damage to livestock and poses a serious social danger. The dynamics of infection with the bovine leukemia virus (LV) have been studied in the Krasnodar Territory for ten years. A decrease in the level of infection of animals with the bovine leukemia virus was noted at livestock enterprises in the public sector and in breeding farms. In the individual sector, due to an imperfect animal insurance system, farmers try to keep IDT+ animals on their farms. Some progress in reducing the infection of cattle with the leukemia virus in the Krasnodar Territory has been achieved through a whole range of measures. This includes the publication of relevant regulations governing the solution of this problem by the state and regional authorities, the coordination of recreational activities by scientists of the Russian Academy of Sciences and employees of the Department of Veterinary Medicine, propaganda work among the population and heads of livestock enterprises, and the introduction by veterinary specialists of modern methods of the early diagnosis of bovine leukemia virus. The order of the Ministry of Agriculture No. 156 dated 03/24/2021 became a timely document to reduce the time of the recovery of cattle from leukemia in Russia. It significantly tightens the requirements to the terms of recovery, regulates the introduction of new methods of the early diagnosis of leukemia. As a part of the implementation of the research topic, the authors proposed a new diagnostic kit for the detection of bovine LV provirus in finished dairy products, which makes it possible to accelerate the identification of infected animals in farms that supply products to dairy plants, and in general, accelerates the elimination of leukemia in Russia.

Effects of selenium nanoparticles produced by Lactobacillus acidophilus HN23 on lipid deposition in WRL68 cells

Selenium is an essential trace element for most organisms, protecting cells from oxidative damage caused by free radicals and serving as an adjunctive treatment for non-alcoholic fatty liver disease (NAFLD). In this study, We used the lactic acid bacterium Lactobacillus acidophilus HN23 to reduce tetra-valent sodium selenite into particulate matter, and analyzed it through inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), X-ray diffraction energy dispersive spectrometry (EDS), and Fourier transform infrared spectroscopy (FTIR). We found that it consisted of selenium nanoparticles (SeNPs) with a mass composition of 65.8 % zero-valent selenium and some polysaccharide and polypeptide compounds, with particle sizes ranging from 60 to 300 nm. We also detected that SeNPs were much less toxic to cells than selenite. We further used free fatty acids (FFA)-induced WRL68 fatty liver cell model to study the therapeutic effect of SeNPs on NAFLD. The results show that SeNPs are more effective than selenite in reducing lipid deposition, increasing mitochondrial membrane potential (MMP) and antioxidant capacity of WRL68 cells, which is attributed to the chemical valence state of selenium and organic composition in SeNPs. In conclusion, SeNPs produced by probiotics L. acidophilus had the potential to alleviate NAFLD by reducing hepatocyte lipid deposition and oxidative damage. This study may open a new avenue for SeNPs drug development to treat NAFLD.

Phenotypic Traits, Hormonal Distribution, and Metabolite Profiling of Isatis indigotica Seeds from 21 Samples in China: A Traditional Chinese Medicinal Herb

"Banlangen" (Isatis indigotica Fort., indigowoad root) is the dried root of a plant in the Cruciferae (Brassicaceae) family, which has been cultivated in China for over 2000 years. This herb has significant medicinal value and played an important therapeutic role during the COVID-19 pandemic. Isatis indigotica is widely cultivated in China, with varying seed quality across different regions. Investigating the seed quality and distribution of endogenous metabolites of Isatis indigotica from various regions is of great significance for its efficient utilization. In this study, 21 samples from Isatis indigotica seeds were collected from 15 different regions of China and analyzed using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). A systematic analysis was conducted on seed phenotypes, germination rate, endogenous metabolites, and hormones. The results showed that the germplasm traits of Isatis indigotica from northern China were generally superior to those from southern China, with seed size positively correlated with the accumulation of sugars (D-allose, D-(+)-cellobiose, maltitol, α-D-glucopyranoside, d-galactose, maltose, D-(-)-fructose, and galactitol) and organic acids (hexadecanoic acid, benzoic acid, propanedioic acid, butanedioic acid, and cinnamic acid). Additionally, seed germination in the samples from SuQian and Shanxi was closely related to hormone distribution (gibberellic acid and abscisic acid). This study provides valuable data to support the evaluation of seeds from different sources of medicinal plants and has important implications for the cultivation and identification of Isatis indigotica varieties.