Жарияланымдар / Публикации

Постоянный URI для этого сообществаhttps://cris.qyzpu.kz/handle/123456789/2

Просмотр

Результаты поиска

Показано: 1 - 4 из 4

Некоторые метрики заблокированы вашими
настройками согласия
The study of induction of 8-methoxypsoralen (8-MOP) SOS-response in bacteria Escherichia coli
(Al-Farabi Kazakh National University, 2020-01-01)
Е. В. Игонина
;
А. А. Лебедева
;
Serikbai K. Abilev
;
Б. С. Жошибекова
8-Methoxypsoralen (8-MOP) is used for photochemotherapy of psoriasis and vitiligo. In therapy, called PUVA therapy, the affected skin of a patient who has previously been prescribed 8-MOP is irradiated with UV-A (> 320 nm). As a result of the photochemical reaction, 8-MOP forms a covalent bond with the pyrimidine bases of DNA and forms both monofunctional and bifunctional adducts. The latter cause 8-MOP-mediated cytotoxicity, leading to the death of psoriatic cells. However, in surviving cells, these same adducts can cause 8-MOP genotoxicity. For a comparative study of the cytotoxicity and genotoxicity of 8-MOP, the E. coli MG1655 lux biosensor (pColD-lux), carrying a recombinant plasmid with a lux operon controlled by the colD gene promoter, was first used. The colD gene (cda) is part of the E. coli SOS-regulon, which provides DNA repair and cell resistance to DNA damage. The death of bacteria was taken into account as an indicator of the cytotoxicity of 8-MOP+UV-A, and the death of bacteria was taken into account by the change in the luminescence intensity of the biosensor. Induction of 8-MOP-mediated SOS-response in bacteria depends on the dose of UV-A, and on the concentration of 8-MOP. At high UV-A doses, a 25-fold decrease in the survival of bacterial cells was detected (from 2 × 108 to 8 × 106 CFU), and in viable cells, an increase in the intensity of the SOS response by 675 times in terms of 106 cells. Thus, it was shown that in the bacterial test system, the genotoxic effect of 8-MOP is several times higher than its cytotoxicity. Key words: 8-methoxypsoralen, lux biosensor, E. coli, colD gene promoter, SOS response, UV radiation, adducts.
Цитирования (OpenAlex) 3Цитирования (OpenCitations) 2
Некоторые метрики заблокированы вашими
настройками согласия
Multifunctional Peptides from Equine Milk Lactoferrin: Evaluation of Antimicrobial Activity In Silico and In Vitro
(Multidisciplinary Digital Publishing Institute, 2026-04-16)
Meiramkul Narmuratova
;
Shara Alpysbayevna Atambayeva
;
Gulzhan K. Kaiyrmanova
;
Saltanat Orazova
;
Gulzhan Narmuratova
The rapid global spread of antimicrobial resistance among pathogenic microorganisms poses a serious challenge to both human and animal health, underscoring the urgent need for new strategies to combat resistance. Antimicrobial peptides (AMPs), key components of the innate immune system, are promising candidates because they disrupt the membranes of bacteria, fungi, and viruses, thereby reducing the risk of resistance development. Lactoferrin (LF), a multifunctional iron-binding glycoprotein abundant in mammalian milk, is a rich source of AMPs. Cationic peptide fragments such as lactoferricin and lactoferrampin exhibit more potent direct antimicrobial activity than the intact protein. Our previous studies have shown that peptides derived from Equine milk lactoferrin exhibit antihypertensive, anti-inflammatory, and anti-oncogenic activity in silico, highlighting their multifunctional bioactive potential. Building on these results, the present study aims to investigate the antimicrobial properties of these peptides. We used an integrated approach combining computer modeling and in vitro studies to identify and validate novel antimicrobial peptides from equine milk lactoferrin. Bioinformatics tools, including AMPScanner and CAMP, were used to predict antimicrobial domains, followed by experimental testing against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The results showed that equine milk lactoferrin peptides possess potent and selective antimicrobial activity, with efficacy varying across bacterial species. These data expand the functional profile of lactoferrin-derived peptides, demonstrating their multifunctionality, and suggest that equine milk lactoferrin represents a promising natural source of antimicrobial agents, supporting alternative strategies to reduce antibiotic use in human and veterinary medicine.
Цитирования (OpenAlex) 2
Некоторые метрики заблокированы вашими
настройками согласия
Development and Study of Hydrophilic Ointment Compositions with a Dextrin/Polyvinyl Alcohol/Iodine Complex (D/PVA/I)
(Multidisciplinary Digital Publishing Institute, 2026-06-22)
Zhassur Taganov
;
Anel Azamatova
;
Roza Karzhaubayeva
;
Gulshat Baigaipova
;
Zhanar A. Iskakbayeva
Background: Iodine-based antimicrobial systems remain highly attractive due to their broad-spectrum activity; however, the clinical application of free iodine is limited by its instability and cytotoxicity. This study aimed to develop polyethylene glycol (PEG)-based hydrophilic ointment formulations containing a dextrin/polyvinyl alcohol/iodine complex (D/PVA/I) and to evaluate their physicochemical properties, antimicrobial activity, and cytotoxicity. Methods: Hydrophilic ointment formulations containing 2.5%, 5.0%, and 10.0% D/PVA/I were prepared using a PEG-based matrix composed of PEG 4000, PEG 400, and glycerol. Physicochemical characterization included organoleptic evaluation, pH measurement, rheological analysis, and UV–visible (Ultraviolet–visible) spectroscopy. Antimicrobial activity was assessed using agar diffusion and minimum bactericidal concentration (MBC) assays against Staphylococcus aureus, Escherichia coli, Enterococcus hirae, and Pseudomonas aeruginosa. Cytotoxicity was evaluated in Madin–Darby Canine Kidney (MDCK) cells using the MTT assay. Results: All formulations exhibited homogeneous semisolid structure and physiologically acceptable pH values (4.94–5.45). Rheological analysis demonstrated non-Newtonian pseudoplastic (shear-thinning) behavior. The flow behavior index (n) ranged from 0.03 to 0.33 according to the Ostwald–de Waele model, confirming shear-thinning characteristics, while viscosity increased with increasing D/PVA/I concentration. UV–visible spectroscopy confirmed the presence of triiodide ions (I3−), characterized by absorption maxima at approximately 287 and 350 nm, indicating preservation of active iodine species within the PEG matrix, while placebo (blank) formulation analysis confirmed the absence of corresponding absorption bands, demonstrating that the PEG-based matrix does not contribute to the characteristic spectral features. The formulations demonstrated broad-spectrum antimicrobial activity, with MBC values ranging from 0.01 to 0.02 µg/mL. Cytotoxicity studies revealed moderate toxicity of the D/PVA/I complex (CC50 = 0.82%) (50% cytotoxic concentration (CC50) and significantly lower toxicity of the PEG-based ointment base (CC50 = 18.38%). Conclusions: The developed PEG-based hydrophilic ointment formulations containing the D/PVA/I complex demonstrated favorable physicochemical characteristics, stability of iodine species, pronounced antimicrobial activity, and acceptable cytotoxicity profiles. These findings highlight the potential for the developed systems to be promising topical antimicrobial formulations.
Цитирования (OpenAlex) 1
Некоторые метрики заблокированы вашими
настройками согласия
D/PVA/I-1 as an Antibiotic Adjuvant: In Vitro Synergy and Membrane Permeabilization in MDR Bacteria
(Multidisciplinary Digital Publishing Institute, 2026-08-17)
Ardak B. Jumagaziyeva
;
Seitzhan Turganbay
;
Anar Seisembekova
;
Daniil Shepilov
;
Zhanar A. Iskakbayeva
Background: Antimicrobial resistance (AMR) is among the most pressing challenges in modern infectious medicine, driving progressive failure of standard antibacterial therapy and rising mortality from infections caused by multidrug-resistant (MDR) pathogens. Antibiotic potentiation through adjuvant compounds capable of restoring the activity of existing drugs represents a promising strategy to overcome resistance without developing fundamentally new antibacterial molecules. This study aimed to evaluate the antibiotic-potentiating activity of a dextrin/polyvinyl alcohol/iodine complex (D/PVA/I-1), developed at the Scientific Center for Anti-Infectious Drugs JSC (Almaty, Kazakhstan), against clinically relevant MDR reference strains. Methods: Nine reference strains, Staphylococcus aureus (ATCC 33591, BAA-39), Escherichia coli (ATCC BAA-196, BAA-2523), Klebsiella pneumoniae (ATCC BAA-2524, 700603), Acinetobacter baumannii (ATCC BAA-1790), Streptococcus pneumoniae (ATCC BAA-660), and Haemophilus influenzae (ATCC 33930), and two clinical isolates, P. aeruginosa SCAID PHRX1-2019 and E. coli SCAID WND1-2021, were tested. Antibiotic-potentiating activity was assessed by checkerboard assay with calculation of the fractional inhibitory concentration index (FICI); bactericidal kinetics were evaluated by time-kill analysis. The effect of D/PVA/I-1 on cytoplasmic membrane permeability was investigated using a crystal violet uptake assay. Results: Of 45 D/PVA/I-1–antibiotic combinations tested across nine antibiotics, synergy (FICI ≤ 0.5) was demonstrated in 44.4% of cases, partial synergy in 48.9%, and additive effects in 6.7%; no antagonistic interactions were detected. The most pronounced potentiating effect occurred against Gram-positive pathogens, particularly MRSA strains (66.7% synergistic combinations). Time-kill analysis confirmed suppression of the regrowth phenotype characteristic of MDR strains under monotherapy and restoration of bactericidal activity against antibiotics to which strains exhibited intrinsic resistance. D/PVA/I-1 induced a dose- and time-dependent increase in membrane permeability in both Gram-positive and Gram-negative organisms. Conclusions: D/PVA/I-1 is an effective broad-spectrum antibiotic potentiator and represents a promising basis for combination therapy regimens against MDR infections.

Жарияланымдар / Публикации

Просмотр

Фильтры

Настройки

Сортировать по

результатов на странице

Результаты поиска

QyzPU CRIS

Университет

Данные