Free Radical Oxidation Research Articles

The status of erythrocyte glutathione in clinical medicine: reality and possibilities

The review examines the current state of free radical oxidation processes in clinical medicine. Based on many years of our research and analysis of the literature, we consider the most promising assessment of the activity of glutathione reductase and the level of glutathione reduced in erythrocytes, as a characteristic of the thiol-disulfide redox system of glutathione, not only to indicate oxidative stress, but also a possible prognostic marker of “free radical diseases”.

Assessment of clinical and laboratory parameters of oral сavity in patients with orthodontic systems

equipment (braces) on the biochemical parameters of oral fluid. Materials and methods. The study involved patients aged 18 to 22 years who are undergoing orthodontic treatment with a bracket system. Thegroup of examined persons was 25 people. The control group included 15 practically healthy people without braces. All patients underwent dental status assessment (Green – Vermillion hygiene index – simplified IG-Y; PMA inflammation index), laboratory examination of oral fluid before and after controlled oral hygiene. The biochemical analysis included determination of the acid-base balance in the oral fluid using a pH meter, assessment of free radical oxidation by chemiluminogram parameters by biochemiluminescence and by levels of molecular products of lipid peroxidation (diene and triene conjugates, Schiff bases), activity of the enzyme alkaline phosphatase, concentrations of total protein and lactate. Results and discussions. In patients undergoing orthodontic treatment with a bracket system, an insufficient level of oral hygiene and inflammatory manifestations in the gums of moderate severity were revealed. The level of the acid-base balance of the oral fluid before controlled hygiene was equal to 6.8±0.19, that is, below the range of normal pH values in the oral cavity. After hygiene, the pH of the oral fluid returned to the norm of 7.1±0.2. In patients with braces, activation of free radical oxidation and an increase in lipoperoxidation parameters – triene conjugates and Schiff bases, increased activity of alkaline phosphatase, total protein and lactate levels took place.Cоnclusion. After hygienic treatment of the oral cavity, the biochemical parameters did not differ statistically significantly from the control data.

The Role of Changes in the Redox Status in the Pathogenesis of Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia is a hemoblastosis of CD5+ B lymphocytes with lymphocytosis, damage to the lymphatic organs, occurring in the older age group, the etiology and pathogenesis of which are not fully understood. Oxidative stress is an important factor in the regulation of stem cells and the activation of intracellular survival signaling pathways in chronic lymphocytic leukemia cells. The aim of the study was to analyze the current data on the role of redox status changes in the pathogenesis of chronic lymphocytic leukemia. A review of published relevant studies 2018-2023, scientific articles in scientific electronic bibliographic databases PubMed and Social Sciences Citation Index, devoted to the pathogenesis of chronic lymphocytic leukemia and the role of free-radical oxidation processes in it was carried out. In chronic lymphocytic leukemia, oxidative stress with a systemic excess of reactive oxygen species, an imbalance in the effectiveness of antioxidant defense is caused mainly by activation of oxidative phosphorylation in mitochondria, low levels of NADPH-oxidase type 2, increased expression of heme oxygenase-1, glutathione peroxidase and glutathione recycling enzymes, superoxide dismutase-2, thioredoxins and decreased expression of catalase. One of the mechanisms of resistance to drug therapy and oxidative stress of chronic lymphocytic leukemia cells is the intracellular signaling pathway dependent on erythroid nuclear factor-2, due to the activation of expression in cells of superoxide dismutase-2, catalase, glutathione peroxidase, peroxiredoxin-3 and-5, heme oxygenase-1, thioredoxin-1 and -2, reduced glutathione, natural killer cell activity, which is associated with lifespan, chemotaxis, proliferation, and survival. FOXO family proteins are believed to suppress carcinogenesis. FOXO3a increases the expression of superoxide dismutase-2, catalase, glutathione peroxidase, peroxiredoxin-3 and -5, and the activity of natural killer cells, which promotes the survival of tumor cells. The development of new targeted pharmacological agents that are capable of accumulating reactive oxygen species and reducing antioxidant protection due to the degradation of erythroid nuclear factor-2 and activation of NADPH-quinone oxidoreductase-1 is underway, which modernizes the therapy of chronic lymphocytic leukemia.

Evaluation of Total Flavonoids, Total Phenolics Content and in Vitro Antioxidant Activities of Extract of Platycerium bifurcatum Leaf: A Potential Antihypertensive Medicinal Plant

Plant bioactive compounds possess the potential to function as antioxidants, which makes interest in the use of ethnomedicine for treatment or prevention of diseases associated with oxidative stress to be growing. This study evaluated the flavonoid contents, total phenolics and in vitro antioxidant activity of Platycerium bifurcatum leaf extract. The free radical scavenging activity was determined using diphenyl-picrylhydrazyl (DPPH) and nitric oxide assay, and the reducing power by ferric reducing antioxidant power (FRAP) and the total antioxidant capacity assays. The total phenolics content of the extract was 4.7 ± 0.56 mg GAE/g extract and flavonoid contents of the extract was 46.73 ± 2.03 mg QE/g extract. The extarct exhibited a dose dependent nitric oxide and DPPH free radical scavenging capacity, which showed a strong correlation between the antioxidant activity and the flavonoid contents and total phenolics. The appreciable amount of flavonoid contents, total phenolics and its strong antioxidant properties suggested that Platycerium bifurcatum is a promising source of novel lead antioxidants and could be utilized in the treatment of oxidative stress mediated cardiovascular disease like hypertensive and obesity

Effect of ultrahigh frequency ozone therapy on oxidative metabolism in the blood of rats with ischemic skin flaps: A preclinical experimental randomized study

Background. Maintaining and restoring skin microcirculation in surgical flaps, as well as accelerating rehabilitation after skin flap transplantation, in order to mitigate the consequences of burns and injuries, remain a pressing issue. In addition to various timings and techniques for plastic surgery, physiotherapeutic approaches prove to be efficient and include low-intensity electromagnetic radiation in millimeter waves as their prominent techniques. In recent years, experts have paid an increasing attention to the application of low-intensity electromagnetic radiation across different frequency ranges for the enhancement of microcirculation in patients after surgical correction of burn consequences. However, this approach is yet to be further validated. Objective. To investigate the effect of different combinations of ultrahigh frequency electromagnetic radiation with ozone therapy on the oxidative metabolism of blood in rats using a model of ischemic skin flaps. Methods. A preclinical experimental randomized study was conducted on 100 adult male Wistar rats weighing between 200 and 250 grams. Five equal-sized groups of animals were formed in the study: Group 1: intact (no interventions), and Groups 2, 3, 4, and 5: after surgical intervention (modeling of ischemic skin flaps). Animals in Group 2 (control group) received no therapeutic procedures. Rats in Groups 3 and 5 underwent a 10-minute course of electromagnetic radiation exposure with a dose of 0.06 mJ for seven days. Animals in Group 3 were exposed to electromagnetic radiation of ultrahigh frequency with a range of 53–78 GHz. Animals in Group 4 received injections of ozonized saline solution (with a saturating ozone concentration in the ozonized oxygen mixture of 3000 µg/L) daily for 7 days, administered intraperitoneally at a volume of 1 mL. Group 5 underwent a combined treatment: daily exposure to ultrahigh frequency electromagnetic radiation along with intraperitoneal ozone therapy (the application modalities of these treatments were similar to those used in Groups 3 and 4, respectively). The intensity of lipid peroxidation, peroxide resistance in erythrocytes, and overall antioxidant system activity were assessed in order to investigate the balance of pro- and antioxidant systems in plasma and erythrocytes. Additionally, the study involved determination of the level of malondialdehyde content and evaluation of the activity of superoxide dismutase and catalase in erythrocytes. The obtained date were analyzed, using MS Office 2013 (Microsoft Corporation, USA) and Statistica 10 (StatSoft, USA). Results. The conducted analysis revealed an antioxidant effect from ultrahigh frequency electromagnetic radiation, with this effect being enhanced by ozone therapy. In addition, the study detected the inhibition of free radical oxidation under the ultrahigh frequency electromagnetic radiation and ozone therapy. Conclusion. Thus, the positive effects of the studied therapeutic factors manifest at the systemic level, as evidenced by the optimization of biochemical parameters and indicators of oxidative metabolism in the plasma of animal blood. It has been established that ultrahigh frequency electromagnetic radiation, administered in a noise mode, exerts a regulatory effect on pro- and antioxidant systems in the body, as demonstrated in a model of transplanted skin flap. This intervention leads to a reduction in the severity of oxidative stress and an enhancement of antioxidant reserves in the blood. The observed effect is further amplified with the additional application of ozone therapy.

Oxidative Stress-mediated Lipid Peroxidation-derived Lipid Aldehydes in the Pathophysiology of Neurodegenerative Diseases.

Neurodegenerative diseases such as Alzheimer's, Parkinson's, and amyotrophic lateral sclerosis cause damage and gradual loss of neurons affecting the central nervous system. Neurodegenerative diseases are most commonly seen in the ageing process. Ageing causes increased reactive oxygen species and decreased mitochondrial ATP generation, resulting in redox imbalance and oxidative stress. Oxidative stress-generated free radicals cause damage to membrane lipids containing polyunsaturated fatty acids, leading to the formation of toxic lipid aldehyde products such as 4- hydroxynonenal and malondialdehyde. Several studies have shown that lipid peroxidation-derived aldehyde products form adducts with cellular proteins, altering their structure and function. Thus, these lipid aldehydes could act as secondary signaling intermediates, modifying important metabolic pathways, and contributing to the pathophysiology of several human diseases, including neurodegenerative disorders. Additionally, they could serve as biomarkers for disease progression. This narrative review article discusses the biological and clinical significance of oxidative stress-mediated lipid peroxidation-derived lipid aldehydes in the pathophysiology of various neurodegenerative diseases.

Modern views on the etiology and role of microbial persistence in the development of inflammatory processes in the periodontal complex (review)

Alveolar tissue diseases cause the appearance of dentition defects, thereby reducing the patients' work capacity and quality of life. The purpose of this research was to investigate, modern views on the etiology of periodontitis and the role of microbial persistence in the development of inflammatory processes of periodontal complex basing on a review of literary sources. Literature review was conducted using PubMed, Web of Science, Scopus, Google Scholar from 2018 to March 2024. There were no restrictions on the date of publication or the language of scientific sources. Searches were conducted according to MeSH (Medical Subject Headings) with using the following search terms: "periodontitis", "oral mucosa", "gums", "dental plaque", "periodontium", "traumatic occlusion", "microorganisms". In total, during the initial analysis 82 literary sources were selected and processed, after further systematization of the selected information using general scientific methods, 70 of them remained. Used methods: bibliographic and analytical. Generalized perio­dontitis is a chronic inflammatory-dystrophic process that occurs as a result of various factors. In the pathogenesis of this disease, the key role is played by the inflammatory process, which is a complex interaction of microcirculatory, he­matological and connective tissue reactions to the lesion. Local (exogenic) and general (endogenic) causative factors are distinguished. The main factors that cause pathological changes in periodontium are bacterial biofilm, traumatic occlusion and various anatomical anomalies. Dental plaque occupies a special and main place among the causes of periodontitis. At present, leading pathogenetic links in the development of the inflammation in the periodontium, in par­ticular, the disruption of free radical oxidation, the processes of peroxide oxidation of lipids and proteins, the disorder of the functional state of the antioxidant system, the formation of oxidative stress, as well as the humoral link of adaptive immune protection and cytokinesis, have not been sufficiently studied. There is no doubt about the role of the microbial factor in the etiology of periodontal diseases, but the penetration of microbes into the periodontium does not always lead to the development of the disease, because the organism has a number of protective mechanisms that counteract the development of inflammation.

The effect of a new 3-hydroxypyridine derivative LHT-2-20 on free radical oxidation in experimental periodontitis

Aim. To study the effect of a new complex compound LHT-2-20 (2-ethyl-6-methyl-3-hydroxypyridine-2-(3benzoyl phenyl)-propanoate) on free radical oxidation in experimental periodontitis.Materials and methods. The experimental study was performed on 195 white mongrel mice weighing 19–23 g and 137 white mongrel rats weighing 180–220 g. The effect of a new complex compound LHT-2-20 (2-ethyl-6methyl-3-hydroxypyridine-2-(3-benzoyl phenyl)-propanoate) on the intensity of free radical oxidation and the local state of periodontal tissues during a course of intragastric administration was studied on the experimental model of periodontitis. Statistical processing of the results was carried out using the SPSS Statistics 20.0 software package with the analysis of variance (ANOVA) and the parametric Tukey’s test.Results. The LHT-2-20 compound reduced elevated levels of primary and secondary lipoperoxidation products (conjugated dienes, malondialdehyde in plasma and in erythrocytes during spontaneous and iron-induced oxidation) already at the early stages of the experiment, bringing the studied parameters closer to the reference values by the end of the course of treatment. The use of the compound LHT-2-20 contributed to an increase in the activity of the main antioxidant enzymes (catalase and superoxide dismutase), normalizing them to baseline values by the end of the experiment. With the correction of free radical processes, the use of LHT-2-20 limited the local inflammatory response in periodontal tissues, which was confirmed by a decrease in gingival edema and hyperemia, bleeding, depth of periodontal pockets, and tooth mobility.Conclusion. The results of this study confirm the anti-inflammatory potential of the compound and the multiplicity of its effects due to the impact on the mechanisms of oxidative stress. The expediency of further study of the drug is justified by the prospect of creating a new drug and its subsequent wide clinical application as part of the complex therapy of periodontal inflammation.

In silico assessment of antioxidant activity and toxicity profiling of bioactive molecules from Murraya koenigii

The antioxidant activity of curry leaves is of interest because oxidative stress is implicated in a variety of diseases, including cancer, heart disease, and neurodegenerative disorders. By scavenging free radicals and inhibiting lipid peroxidation, antioxidants can help protect cells from damage and reduce the risk of these diseases. Overall, in-silico studies suggest that curry leaves and their bioactive compounds have potent antioxidant activity. The objective of the study was to assess the antioxidant activity of the bioactive molecules from Murraya koenigii and anticipate the toxicity by in-silico research. iGEMDOCK software was used to assess the antioxidant activity. ProTox II software was used to conduct the toxicity investigations. Osthol (− 81.4863, − 81.9046 kcal/mol), mukoenineA (− 81.0417, − 78.9941 kcal/mol), murrayone(− 80.0731, − 78.9453 kcal/mol), kaempferol (− 97.0774, − 89.3534 kcal/mol), and apigenin (− 89.5291, − 108.704 kcal/mol) were found to have the highest binding energies with SOD and GPx proteins, respectively, when compared with standard (ascorbic acid; − 81.132, − 98.917 kcal/mol). All the mentioned compounds have low levels of hepatotoxicity, carcinogenicity, immunotoxicity, mutagenicity, and cytotoxicity. The bioactive molecules of Murraya koenigii have a potent antioxidant effect and low level of toxicity that gives valuable insight for optimizing lead molecules to combat free radical generation or oxidation.

Effect of chloride ions on the reactive species change pathway and removal performance in the MW/Co2+/PMS process

Efficient removal of refractory organic matter is the focus of research in the treatment of actual wastewater with Peroxymonosulfate-based advanced oxidation processes(PMS-AOPs). However, the high concentration of chloride ions (Cl−) ubiquitously present in wastewater changes the reactive species (RS) present in the process, and the mechanism of this change is still not clear. This study investigated the effects of Cl− on the transformation behavior of RS and treatment performance under microwave (MW) combined with cobalt ions (Co2+)-activated PMS. The results showed that increasing the Cl− concentration can enhance the removal performance of the MW/Co2+/PMS process for ammonia (NH4+-N), accompanied by the production of nitrate nitrogen (NO3-N), monochloramine (NH2Cl) and dichloramine (NHCl2), which was related to the transformation of existing reactive oxygen species (ROS, •OH and SO4•−) into reactive chlorine species (RCS), with hypochlorous acid (HClO) as an important intermediate. Cl− can generate HClO through free radical oxidation (•OH and SO4•−) dominance and non-free radical oxidation (PMS and Co3+) promotion, and the heat transferred by MW can further trigger conversion between HClO and PMS, thereby changing the distribution of RS. Increasing the dosage of PMS and the dosage of Co2+ promoted the transformation of Cl− to reactive species in the MW/Co2+/PMS process. At MW power=160W, [Co2+]=17.5μM,[PMS]=10mM, and [Cl−]=17mM, the maximum cumulative [HClO] reached 1910.97μM, and the decay rate was 0.1815 min-1.The macromolecular organic matter in aqueous environment competes with ammonia for the RCS. Through regulating [Cl−] in mature leachate, RCS has a certain oxidation effect to organic matter, but its limited oxidation ability leads to a decrease in the mineralization effect.

Oxygen vacancy and boron dual sites enable efficient oxygen activation for emerging contaminant degradation: Boosted exciton dissociation via built-in electric field modulation

Two-dimensional (2D) layered materials are promising photocatalysts for environmental remediation through O2 activation. However, the inherent robust excitonic effects from the confined-layer structure hinder the generation of highly oxidative free radicals from the preferred charge transfer pathway. Taking 2D BiOBr as a prototype, we implemented a superficial surface boronizing method to incorporate oxygen vacancy (OV)-boron (B) dual sites onto the surface. The OV-B dual sites disorder the surface atomic arrangement of BiOBr and induce strong built-in electric field (BEF). This effectively weakens exciton binding energy, boosts exciton dissociation into free charges, and facilities the transfer and separation of free charges, which collectively enables charge transfer to surpass excitonic effects as the dominant O2 activation pathway. Consequently, BiOBr with OV-B dual sites outperforms pristine and mono-OV modified BiOBr in both O2 activation and emerging contaminant degradation. This work offers insightful strategies for modulating 2D photocatalysts to optimize O2 activation towards efficient contaminant removal.

Возможности метода биохемилюминисценции с модельной средой из сыворотки крови в оценке антиоксидантной активности растительного сырья

Antioxidant activity (AOA) is an important indicator of the evaluation of plant raw materials (RM), which are widely used in medicine to obtain various medicines. The use of RM at the present stage of the pharmaceutical industry development allows avoiding large-scale production of synthetic medicines, accompanied by a negative impact on the environment. For an objective assessment of AOA, it is necessary to apply methods that allow determining not only the content of the active substance, but also generally characterizing the functional activity of RM. The article presents data on the AOA of aqueous extracts from the leaves and fruits of Hippophae rhamnoides L., Aronia melanocarpa L. The determination of antioxidant activity was performed by biochemiluminiscence (BСHL) using serum from white mongrel rats as a model environment (MЕ). The evaluation criteria were the maximum intensity (Imax) and the light sum of the glow (S). The results obtained were compared with the data of the analysis of BCHL without ME, as well as with the data of alternative methods for quantifying the antioxidant potential of RM (coulometric titration, direct titration, spectrophotometry). According to the criteria for assessing the intensity of free radical oxidation (Imax) using the BCHL method without ME, it was found that aqueous extracts from the leaves and fruits of A. melanocarpa, as well as H. rhamnoides leaves, have a high antioxidant potential (343, 274 and 268 mV, respectively), and from H. rhamnoides fruits – more short. BCHL results showed that the amount of radicals in blood serum decreased upon contact with extracts from vegetable raw materials. Among the studied samples, extracts from the fruits of A. melanocarpa were characterized by the highest AOA (S=2006±137 mV·s). At the same time, according to alternative methods, they occupy an intermediate position in terms of the quantitative content of biologically active substances (BAS) with antioxidant properties. Based on the weak correlation between the data of the BСHL method and alternative methods for determining AOA, it is concluded that it is necessary to take into account the possibility of an indirect relationship between the content of BAS in RM and the effect manifested in conditions as close as possible to biological systems. The measurement of AOA by the BСHL method is actually an assessment of the function, as well as the effectiveness of BAS, and complements quantitative methods for assessing the antioxidant activity of ME.

Treatment of high-concentration semi-coke wastewater by phenolic condensation and persulfate oxidation

In this study, the combined process of phenolic condensation-persulfate(PS) advanced oxidation was adopted to treat semi-coking wastewater. Using the phenolic condensation method as a pretreatment unit to remove phenolic substances for the preparation of phenol-formaldehyde resins, and using an aerated/PS/pyrite oxidation system as a deep treatment unit to remove chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) from the wastewater. Analysis and characterization of phenol-formaldehyde resin, organic compounds in wastewater, and pyrite using FT-IR, TG-DTG, GC-MS, and XPS techniques. The results showed that under the conditions of adding 1.8vt % formaldehyde, pH 10.5, reaction temperature 95 ℃ and reaction time 3 h, the removal rates of volatile phenol, COD and NH3-N in semi-coke wastewater were 97.54 %, 41.14 % and 56.50 %, and the yield of phenolic resin was 6.62 g/L. Subsequently, treated with an aerated/PS/pyrite system, the PS concentration 0.4 mol/L, the pyrite dosage 15 g/L, the pH 3, the temperature 65 ℃, and the aeration 3 h, the removal rates of COD and NH3-N are 99.20 % and 86.80 %. In the phenolic condensation process, phenolic substances in semi-coke wastewater generate phenoxy anions under the influence of OH-, which undergo addition reactions with formaldehyde to produce hydroxymethyl phenol. Hydroxymethyl phenol further undergoes condensation reactions with other phenolic substances and itself to form phenolic resin, while amide compounds are generated through reactions between ammonia nitrogen and carboxylic acid substances. In the aeration/PS/pyrite system, Fe2+ released from pyrite oxidation activates PS to produce SO4•− and O2•−. The contribution of free radical oxidation and decomposition of pollutants such as phenols, amides, and NH3-N in wastewater is 84.60 %. Specifically, SO4•− oxidation contributes 61.54 %, while O2•− accounts for 22.21 %. Amide compounds and phenolic substances in the wastewater are oxidized, leading to ring opening and chain scission, resulting in the formation of alkane compounds.

Investigating In Silico and In Vitro Therapeutic Potential of Diosmetin as the Anti-Parkinson Agent.

This study aimed to investigate how diosmetin interacts with seven target receptors associated with oxidative stress (OS) and validate its antioxidant properties for the potential management of Parkinson's disease (PD). In PD, the degeneration of dopaminergic cells is strongly influenced by OS. This stressor is intricately connected to various mechanisms involved in neurodegeneration, such as mitochondrial dysfunction, neuroinflammation, and excitotoxicity induced by nitric oxide. The aim of this research was to establish a molecular connection between diosmetin and OS-associated target receptors was the goal, and it investigated how this interaction can lessen PD. Seven molecular targets - Adenosine A2A (AA2A), Peroxisome Proliferator- Activated Receptor Gamma (PPARγ), Protein Kinase AKT1, Nucleolar Receptor NURR1, Liver - X Receptor Beta (LXRβ), Monoamine Oxidase - B (MAO-B) and Tropomyosin receptor kinase B (TrkB) were obtained from RCSB. Molecular docking software was employed to determine molecular interactions, while antioxidant activity was assessed through in-vitro assays against various free radicals. Diosmetin exhibited interactions with all seven target receptors at their binding sites. Notably, it showed superior interaction with AA2A and NURR1 compared to native ligands, with binding energies of -7.55, and -6.34 kcal/mol, respectively. Additionally, significant interactions were observed with PPARγ, AKT1, LXRβ, MAO-B, and TrkB with binding energies of -8.34, -5.42, -7.66, -8.82, -8.45 kcal/mol, respectively. Diosmetin also demonstrated antioxidant activity against various free radicals, particularly against hypochlorous acid (HOCl) and nitric oxide (NO) free radicals. Diosmetin possibly acts on several target receptors linked to the pathophysiology of PD, demonstrating promise as an OS inhibitor and scavenger.

Preparation of Composite Hydrogels Based on Cysteine-Silver Sol and Methylene Blue as Promising Systems for Anticancer Photodynamic Therapy.

In this study, a novel supramolecular composite, "photogels", was synthesized by mixing of cysteine-silver sol (CSS) and methylene blue (MB). A complex of modern physico-chemical methods of analysis such as viscosimetry, UV spectroscopy, dynamic and electrophoretic light scattering, scanning electron microscopy and energy-dispersive X-ray spectroscopy showed that MB molecules are uniformly localized mainly in the space between fibers of the gel-network formed by CSS particles. Molecules of the dye also bind with the surface of CSS particles by non-covalent interactions. This fact is reflected in the appearance of a synergistic anticancer effect of gels against human squamous cell carcinoma even in the absence of light irradiation. A mild toxic influence of hydrogels was observed in normal keratinocyte cells. Photodynamic exposure significantly increased gel activity, and there remained a synergistic effect. The study of free-radical oxidation in cells has shown that gels are not only capable of generating reactive oxygen species, but also have other targets of action. Flow cytometric analysis allowed us to find out that obtained hydrogels caused cell cycle arrest both without irradiation and with light exposure. The obtained gels are of considerable interest both from the point of view of academics and applied science, for example, in the photodynamic therapy of superficial neoplasms.

Корекція пробіотиком пародонтального синдрому у тварин за умов ожиріння і хронічного стресу

The aim of this study was to investigate the effect of obesity and chronic stress on periodontal tissues, both separately and in the combined comorbidity of these conditions in rats, and the role of the probiotic Lactobacillus casei in the correction of periodontal syndrome under these conditions. Methods. The development of periodontal syndrome and the effectiveness of the probiotic Lactobacillus casei IMV B-7280, administered to rats from one month of age intragastrically in a volume of 1 mL (5 · 108 CFU) in two-week courses with breaks of 2 weeks, were studied in a model of glutamate-induced obesity and chronic stress - in combination and separately. In periodontal tissues, the total proteolytic and antitryptic activity, free fucose and glycosaminoglycans (GAG) content, catalase activity, thiobarbiturate active products (TBA reagents), and the content of oxidatively modified proteins (OMP) and molecules of average mass (AMM) were determined; in bone tissue, the molar root exposure coefficient was calculated. The anthropometric parameters of the animals and the Selye triad were studied. Results. We have substantiated the development of periodontal syndrome in animals with glutamate-induced obesity against the background of chronic stress, as evidenced by the activation of free radical oxidation of lipids and proteins, depolymerization of fucoproteins and proteoglycans of periodontal connective tissue, which causes exposure of molar roots by almost 65%. The administration of the probiotic Lactobacillus casei in two-week courses with intervals of 2 weeks to obese rats with chronic stress prevented the development of obesity, as evidenced by a significant decrease in visceral fat mass, Li index, and BMI, as well as the severity of stress syndrome, as evidenced by a decrease in ulcer formation, thymus involution, and adrenal hypertrophy. The periodontoprotective effect of Lactobacillus casei under the combined influence of obesity and chronic stress was proved by significant changes in oxidative stress, free fucose, and GAG content and a 1.5-times decrease in the molar root exposure ratio. Conclusions. Periodic administration of Lactobacillus casei to rats treated with sodium glutamate in the neonatal period against the background of chronic stress prevented the development of obesity, the severity of stress syndromeб and damage to periodontal tissues, as evidenced by the prevention of oxidative stress, increased catabolism of extracellular connective tissue proteins and antiresorptive effect.

Investigating the Antioxidant Capacity of Newly Synthesized Flavonoids via DPPH Assay.

Numerous naturally occurring and artificially synthesized flavonoids have garnered attention for their impressive ability to combat oxidative stress and scavenge free radicals when evaluated in laboratory settings. The core aim of our investigation revolved around assessing the antioxidant potential of a diverse range of synthesized flavonoids through in vitro experiments. We crafted 29 distinct flavonoids using the aldol condensation mechanism via a chalcone intermediate to accomplish this. We meticulously characterized these newly formed compounds using a variety of spectroscopic techniques. We employed the widely recognized DPPH free radical method for the crucial antioxidant evaluation, a benchmark in such studies. The radical scavenging efficacy of our synthesized flavonoids was then meticulously compared to that of the positive control, ascorbic acid, renowned for its antioxidant prowess, and the IC50 values for each compound were calculated and examined. Surprisingly, our results showed that the flavonoids we tested had a wide range of antioxidant activity, with IC50 values that ranged from 75.8 ± 8.30 to 397 ± 25.10 μg/mL. Intriguingly, compounds US5, US13, US16, US17, US18, and US21 outshone even ascorbic acid in their antioxidant potential, displaying remarkable scavenging abilities against free radicals. This discovery holds promise for further exploration of these compounds as potential antioxidants with potential applications in health and wellness.

EFFECT OF MONOAMINE OXIDASE INHIBITOR ON FREE RADICAL OXIDATION IN RAT KIDNEYS WITH ALLOXAN-INDUCED HYPERGLYCEMIA

Introduction. One of the most severe and dangerous complications of diabetes mellitus (DM) is diabetic nephropathy, the leading pathogenetic factor of which is considered to be prolonged hyperglycemia with the development of oxidative stress. Several leading redox-dependent mechanisms of diabetic nephropathy have been described, among which an important role is played by oxidases, as a key link in the redox balance in podocytes. The kidneys are characterized by high activity of monoamine oxidases (MAO), which are active producers of hydrogen peroxide. Meanwhile, the contribution of monoamine oxidases to the development of oxidative stress in the kidneys under conditions of prolonged hyperglycemia remains unexplored. Purpose of the study – to assess the contribution of monoamine oxidases to the development of oxidative stress in the kidneys under conditions of long-term hyperglycemia induced by alloxan. Material and methods. The study was conducted on 111 Wistar rats of both sexes, weighing 180–250 grams. Diabetes mellitus was modeled by intraperitoneal administration of alloxan monohydrate at a dose of 163 mg/kg. To assess the contribution of MAO-B to the development of oxidative stress, the selective MAO-B inhibitor selegiline was used at a dose of 5 mg/kg. Throughout the experiment, glycemia and body weight of the animals were monitored. Animals were removed from the experiment on the seventeenth day. The levels of oxidative modification of proteins, lipid peroxidation products, as well as the activity of monoamine oxidases A and B in kidney homogenates were determined by spectrophotometric methods. Results. It was found that on the fourteenth day from the moment of alloxan administration, signs of oxidative stress (increased oxidative modification of proteins) are revealed in the kidneys. The results of the correlation analysis demonstrate direct correlations in the "Alloxan" group of animals between the level of blood glucose on the 14th day of the experiment and the levels of products of oxidative modification of proteins, as well as the activity of MAO-B and the levels of products of oxidative modification of proteins and primary heptane-soluble lipid peroxidation products in kidneys. The absence of this kind of relationship in the group of animals that additionally received a MAO-B inhibitor ("Alloxan + selegiline"). Conclusions. The results of the study confirms the contribution of the intensification of free radical oxidation to the development of diabetic nephropathy during prolonged hyperglycemia, on the one hand, and the prooxidant effect of MAO-B on the other

A step to microplastic formation: Microcracking and associated surface transformations of recycled LDPE, LLDPE, HDPE, and PP plastics exposed to UV radiation

Plastics when exposed to UV radiation start to degrade via photooxidative aging including free radical formation, oxidation, chain scission and/or crosslinking reactions. These chemical changes can cause loss in mechanical strength, surface embrittlement, and eventually surface erosion. The eroded particles are microplastics (MPs), which have been identified as a potentially serious threat to the environment and its inhabitants. In general, photodegradation of virgin plastics has been studied extensively, but there is not much literature on the degradation of recycled plastics. The goal of the study was to investigate the changes caused by photodegradation in recycled plastics and assess the potential risks of MPs formation. And eventually, knowing the chemical and physical transformations occurring on the surface understand the mechanism behind surface microcracking, which is the first step of MPs formation. Pellets of five industrially recycled plastics (low-density polyethylene (rLDPE), linear low-density polyethylene (rLLDPE), high-density polyethylene (rHDPE), and two polypropylenes (rPP)) from different waste sources were analysed. UV irradiation was performed in an accelerated weathering chamber for milled (< 400 µm) plastic powder to ensure homogeneous changes throughout the sample. The properties were investigated by ATR-FTIR, HT-SEC, XPS and DSC. Formation of microcracks was studied on plastic pellets by SEM. The results showed that the degradation significantly differed between the recycled plastics, and the waste source was more important than the plastic type. rLDPE and one of the rPP samples showed a significant increase in carbonyl index as well as decrease in molar mass during the first 500 h of UV exposure. The other rPP and rHDPE samples showed first considerable signs of degradation only after 1000 h of UV exposure. Minor changes were observed for the rLLDPE sample during the whole test. The SEM revealed microcracking on the surface of all samples, which also had noticeable degradation identified by other methods. These recycled plastics can be considered the ones with the highest potential of MPs formation. From the chemical and physical transformations identified on the surface, the mechanism leading to microcracking, which is the first step in the formation of MPs, is proposed.

Free radical fragmentation and oxidation in the polar part of lysophospholipids: Results of the study of blood serum of healthy donors and patients with acute surgical pathology

The interaction of reactive oxygen species with cell membrane lipids is usually considered in the context of lipid peroxidation in the nonpolar component of the membrane. In this work, for the first time, data were obtained indicating that damage to human cell membranes can occur in the polar part of lysophospholipids at the interface with the aqueous environment due to free radical fragmentation (FRF) processes. FRF products, namely 1-hexadecanoyloxyacetone (PAc) and 1-octadecanoyloxyacetone (SAc), were identified in human serum, and a GC-MS method was developed to quantify PAc and SAc.The content of FRF products in serum samples of 52 healthy donors was found to be in the range of 1.98–4.75 μmol/L. A linear regression equation, CPAc&SAc (μmol/L) = 0.51 + 0.064 × years, was derived to describe the relationship between age and content of FRF products. In 70 patients with acute surgical pathology in comparison with the control group of healthy donors, two distinct clusters with different concentration levels of FRF products were revealed. The first cluster: groups of 43 patients with various localized inflammatory-destructive lesions of hollow organ walls and bacterial translocation (septic inflammation) of abdominal cavity organs. These patients showed a 1.5–1.9-fold (p = 0.012) decrease in the total concentration of PAc and SAc in serum. In the second cluster: groups of 27 patients with ischemia-reperfusion tissue damage (aseptic inflammation), – a statistically significant increase in the concentration of FRF products was observed: in 2.2–4.0 times (p = 0.0001).The obtained data allow us to further understand the role of free-radical processes in the damage of lipid molecules. FRF products can potentially be used as markers of the degree of free-radical damage of hydroxyl containing phospholipids.