Hydroxyl Radical Content Research Articles

Maillard reaction products inhibit lipid oxidation by regulating myoglobin stability in washed muscle model.

Lipid oxidation significantly contributes to muscle deterioration, with heme protein oxidation playing a crucial role in this process. This study investigated the inhibition of heme protein oxidation by Maillard reaction products (MRPs) using a washed muscle model combining washed carp with myoglobin (Mb). Protein oxidation products, protein texture, and lipid oxidation levels were assessed. Results showed that metmyoglobin (MetMb) is a primary driver of lipid oxidation in meat, likely due to Mb oxidation, exposing hydrophobic groups that bind to lipids. MRPs at concentrations of 0.5% and 1% effectively inhibited Mb oxidation. Specifically, treatment with 1% MRPs reduced MetMb formation by 15.38%, protein carbonyl content by 6.53%, hydroxyl radical content by 20.37%, protein aggregation by 40.81%, and particle size by 36.95% during later storage stages, thereby preserving Mb stability. In the Mb-mediated oxidation model, 1% MRPs inhibited the formation of primary and secondary oxidative metabolites by 59.47% and 68.19%, respectively, while maintaining muscle tissue texture integrity. PRACTICAL APPLICATION: The antioxidation of Maillard reaction products (MRPs) improves the stability of common carp. By inhibiting the autoxidation of myoglobin and lipid, MRPs help preserve the texture and color of fish muscle while extending its shelf life. This study provides a valuable reference for effectively controlling lipid oxidation in refrigerated fish products and enhancing their overall quality.

Effects of erythromycin on biofilm formation and resistance mutation of Escherichia coli on pristine and UV-aged polystyrene microplastics

Microplastics (MPs) and antibiotics co-occur widely in the environment and pose combined risk to microbial communities. The present study investigated the effects of erythromycin on biofilm formation and resistance mutation of a model bacterium, E. coli, on the surface of pristine and UV-aged polystyrene (PS) MPs sized 1–2 mm. The properties of UV-aged PS were significantly altered compared to pristine PS, with notable increases in specific surface area, carbonyl index, hydrophilicity, and hydroxyl radical content. Importantly, the adsorption capacity of UV-aged PS towards erythromycin was approximately 8-fold higher than that of pristine PS. Biofilms colonizing on UV-aged PS had a greater cell count (5.6 × 108 CFU mg−1) and a higher frequency of resistance mutation (1.0 × 10−7) than those on pristine PS (1.4 × 108 CFU mg−1 and 1.4 × 10−8, respectively). Moreover, erythromycin at 0.1 and 1.0 mg L−1 significantly (p < 0.05) promoted the formation and resistance mutation of biofilm on both pristine and UV-aged PS. DNA sequencing results confirmed that the biofilm resistance was attributed to point mutations in rpoB segment of the bacterial genome. qPCR results demonstrated that both UV aging and erythromycin repressed the expression levels of a global regulator rpoS in biofilm bacteria, as well as two DNA mismatch repair genes mutS and uvrD, which was likely to contribute to increased resistance mutation frequency.

Heat Shock Protein HSP27 and the Status of the Glutathione System in Dexamethasone-Induced Apoptosis of Jurkat Tumor Cells.

We studied the effect of the HSP27 inhibitor, 5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl)-isoxazole, at a final concentration of 0.1 μM and/or the apoptosis inducer dexamethasone at a final concentration of 10 μM on the content of hydroxyl radical, reduced and oxidized glutathione, HSP27, activity of glutathione reductase, glutathione peroxidase, caspase-3, and the number of Annexin+ Jurkat tumor cells. The involvement of HSP27 in apoptosis of Jurkat tumor cells was demonstrated. Simultaneous exposure to the HSP27 inhibitor and dexamethasone resulted in an increase in the level of HSP27 against the background of developing oxidative stress (increase in the concentration of hydroxyl radicals and changes in the state of the glutathione system).

The role of ubiquitin and heat shock proteins 27 and 70 in the oxidative modification of proteins and the implementation of dexamethasone-induced apoptosis of tumor cells

BACKGROUND: Experimental studies of molecular control of the tumor cell’s redox status, which influences the implementation of apoptosis, are relevant for studying the pathogenesis of tumor growth.&#x0D; AIM: Studying the molecular mechanisms of the participation of ubiquitin and heat shock proteins 27 and 70 in the oxidative modification of proteins, amino acids and the implementation of dexamethasone-induced apoptosis of Jurkat tumor cells in conditions of decreased antioxidant protection by blocking the synthesis of reduced glutathione.&#x0D; MATERIAL AND METHODS: The effect of the inhibitor of de novo glutathione synthesis buthionine sulfoximine at a final concentration of 1 mM and/or the apoptosis inducer dexamethasone at a final concentration of 10 μM on the content of hydroxyl radical, protein-bound glutathione, carbonyl derivatives of proteins, oxidized tryptophan and bityrosine, ubiquitin, heat shock proteins 27 and 70, number of annexin V-positive cells and caspase-3 activity in Jurkat tumor cells was studied. Using the Shapiro–Wilk test, the normality of the distribution of indicators was assessed. Statistical hypotheses about the differences between the study groups were tested using the nonparametric Mann–Whitney test with a Bonferroni correction; correlation analysis was performed using the Spearman method at a significance level of p 0.05.&#x0D; RESULTS: In tumor cells of the Jurkat line, exposure to buthionine sulfoximine and dexamethasone was accompanied by a statistically significant decrease in the content of ubiquitin by 24% (p=0.004), protein-bound glutathione by 93% (p=0.003), oxidized tryptophan by 57% (p=0.003), and heat protein shock 70 by 56% (p=0.004), as well as an increase in the concentration of carbonyl derivatives of proteins by 53% (p=0.004), heat shock protein 27 by 104% (p=0.004), associated with an increase in the number of annexin-positive cells by 1296% (p=0.006) and caspase-3 activity by 258% relative to the values in intact cells. The relationship between an increase in the number of annexin-positive cells and caspase-3 activity with changes in the content of protein-bound glutathione, carbonylated proteins, oxidized tryptophan, ubiquitin and heat shock proteins 27 and 70 in tumor cells with simultaneous exposure to both buthionine sulfoximine and dexamethasone has been proven.&#x0D; CONCLUSION: Blocking de novo glutathione synthesis and stimulating apoptosis causes activation of reversible and irreversible oxidative modification of proteins and amino acids against the background of increased oxidative stress in Jurkat tumor cells.

Bactericidal Effect and Associated Properties of Non-Electrolytic Hypochlorite Water on Foodborne Pathogenic Bacteria.

This study investigated the broad-spectrum bactericidal activity of non-electrolytic hypochlorite water (NEHW) and detected its hydroxyl radical content compared with that of slightly acidic electrolytic water (SAEW). Based on the results of UV scanning and storage stability, higher hypochlorite content and stronger oxidation were found to be responsible for the stronger bactericidal effect of NEHW. NEHW can achieve 99% bacterial disinfection effect by treating with 10 mg/L available chlorine concentration for more than 5 minutes. At the same time, the storage stability of NEHW was higher than that of SAEW. After 20 days of storage under sealed and dark conditions, the pH value only increased by 7.9%, and the effective chlorine concentration remained nearly 80%. The results showed that NEHW had higher germicidal efficacy and storage stability than SAEW.

Mesoporous MoS2 incorporated zirconia nanocomposites: Simple synthesis, characterization and photocatalytic desulfurization of thiophene under visible light

The petroleum sector has focused its efforts on developing low-sulfur fuels because of rigorous regulatory requirements enforced by various countries. In this context, mesoporous MoS2/ZrO2 nanostructures were simply manufactured and subsequently adopted under visible light for photocatalytic desulfurization of thiophene (PDT). Actually, PDT was extensively upgraded upon the application of MoS2/ZrO2 nanostructures especially when the results compared to pure ZrO2. The pseudo-first-order model was the best model that was found to properly fit such a reaction. Amongst all manufactured specimens, the photocatalytic efficiency of the 1.5 wt% MoS2/ZrO2 nanostructured material was the maximum. The reaction rate of PDT upon utilizing optimized material was 0.01577 min−1 whiles that upon the application of pure ZrO2 was 0.000513 min−1. And so, PDT rate was 30.5 times greater over 1.5 wt% MoS2/ZrO2 nanostructured material than over pure ZrO2. The photocatalytic oxidation of thiophene over the manufactured materials yielded SO3 and CO2. The distinct photocatalytic effectiveness of MoS2/ZrO2 might be associated with the competent absorption of visible light, fast movement of thiophene molecules to active centres, expanded hydroxyl radical content and diminished light scattering. The recyclability test acknowledged that MoS2/ZrO2 nanostructured material was remarkably stable against PDT under visible light. The mechanism of the PDT reaction utilizing the photo-created charges was discussed.

α-(Fe, Cu)OOH/RGO nanocomposites for heterogeneous photo-Fenton-like degradation of ciprofloxacin under visible light irradiation.

Ciprofloxacin (CIP) is a third-generation fluoroquinolones (FQs) antibiotic, and the occurrence of CIP in the water environment has raised growing concerns owning to its environmental toxicity. In this paper, a novel α-(Fe, Cu)OOH/RGO nanocomposite was synthesized via a one-step reflux method for CIP degradation through a photo-Fenton-like process. When the RGO content was 1 wt%, CIP degradation ratio by the α-(Fe, Cu)OOH/RGO nanocomposite reached 100% under visible light irradiation within 120 min, and total organic carbon (TOC) removal ratio reached 60% within 180 min. The result of molecular fluorescence spectra highlighted that the loading of RGO on the α-(Fe, Cu)OOH significantly increased the content of hydroxyl radicals (·OH) in the heterogeneous photo-Fenton-like system and simultaneously inhibited the recombination of photogenerated electron and hole, which played critical roles in the enhancement of CIP degradation. In addition, 11 main intermediates were identified as the degradation products of CIP in the α-(Fe, Cu)OOH/RGO/H2O2/visible light reaction systems using liquid chromatograph-mass spectrometer (LC-MS) analyses. The results demonstrated that three degradation pathways for CIP removal by α-(Fe, Cu)OOH/RGO nanocomposite occurred, including (i) oxidation on the piperazine ring and dealkylation, (ii) defluorination and decarboxylation, and (iii) hydroxylation on the quinolone ring. This work would provide a novel insight of CIP degradation pathways in photo-Fenton-like processes.

Potential health risks of the interaction of microplastics and lung surfactant

Microplastics (MPs), as pollutants of environmental concern, are correlated with increased risk of various respiratory diseases. Nevertheless, whether or not MPs have adverse influences on the interfacial properties of lung surfactant (LS), and its effect on the generation of reactive oxygen species are poorly understood. In the present study, natural LS extracted from porcine lungs was used to investigate the interaction with polystyrene as a representative MPs. The results showed that the phase behavior, surface tension, and membrane structure of the LS were altered in the presence of polystyrene. Adsorption experiments demonstrated that in the mixed system of polystyrene and LS (the main active ingredients are phospholipids and proteins), adsorption of phospholipid components by polystyrene was notably higher than that of proteins. Moreover, polystyrene can accelerate the conversion between ascorbic acid and deoxyascorbic acid, thereby producing hydrogen peroxide (HOOH) in simulated lung fluid (containing LS) and further giving rise to an increase in the content of hydroxyl radicals (•OH). This work provides new insight into the potential hazard of MPs in human respiratory system, which is helpful for deeply understanding the unfavorable physicochemical effects of MPs exposure and the role of inhaled MPs on lung health.

Medicinal Plants Extracts Impact on Oxidative Stress in Mice Brain Under the Physiological Conditions: the Effects of Corn Silk, Parsley, and Bearberry.

This study was performed to examine the effects of medicinal plant extracts of corn silk (Stigma maydis), parsley leaf (Petroselini folium), and bearberry leaf (Uvae ursi folium) on antioxidant status of the brain of experimental animals (mice) under the physiological conditions. Biological properties of these plants are insufficiently investigated and the aim was to explore their possible antioxidant effects that can alleviate oxidative damage of the brain tissue. Corn silk extract showed positive effect on activities of antioxidant enzymes in mice brain tissue. Parsley extract induced the increase in glutathione content and decrease of lipid peroxidation. Bearberry leaf extract induced catalase activity and decrease of hydroxyl radical content, while malonyldialdehide accumulation was maintained at the control level. Results obtained in this study support the use of corn silk, parsley and bearberry leaves as natural antioxidant sources in the prevention and treatment of brain tissue damages and different diseases caused by oxidative stress.

An underlying softening mechanism in pale, soft and exudative – Like rabbit meat: The role of reactive oxygen species – Generating systems

This work investigated the role of reactive oxygen species (ROS) - generating systems on the softening of the pale, soft and exudative-like (PSE-like) rabbit meat during aging. PSE-like meat was induced by incubation of post-mortem rabbit Longissimus thoracis et lumborum at 37 °C for 3 h. During aging, PSE-like meat samples had higher values in peroxides value, thiobarbituric acid-reactive substances, metmyoglobin percentage, ferrylmyoglobin content, non-heme iron content, hydroxyl radical content and ROS concentration compared with the normal ones, suggesting that PSE-like incubation could activate lipid-oxidizing system, myoglobin-mediated oxidation system, together with metal-catalyzed oxidation system. Additionally, higher protein carbonyl content was observed in PSE-like meat, along with a significant loss in sulfhydryl group. The results of SDS-PAGE suggested that more serious protein degradation occurred in PSE-like meat. It is plausible that the activated ROS-generating system played an underlying role in the softening texture during the aging period of PSE-like meat.

Preparation of Antarctic Krill Oil Emulsion and Its Stability under Catalase Treatment.

Making Antarctic krill oil into emulsion is a good way to utilize Antarctic krill, but proliferation of microorganisms cannot be ignored. H2O2 is widely used in the sterilization of liquid food since its decomposition products are environmentally friendly, although residual H2O2 should be removed for food safety. Adding catalase (CAT) is an effective means to do this. However, the enzyme activity center of CAT is the iron porphyrin group, which has the risk of accelerating lipid oxidation in the oil emulsion. Therefore, we hypothesized that CAT might not be suitable for the removal of H2O2 in Antarctic krill oil emulsion. In this paper, Antarctic krill oil emulsion was prepared, and then the effect of CAT on the emulsion was studied through visual observation, microscopic morphology observation, turbidity and stability, particle size, and ζ-potential; finally, the mechanism of CAT destroying the emulsion was explored from the perspective of lipid oxidation. The results showed that a stable Antarctic krill emulsion was prepared using Tween-80 as the emulsifier, with the oil concentration of 1% (v/v) and the ratio of surfactant to oil phase of 1:5 (v/v). The emulsion treated with CAT had undergone demulsification, stratification, and coagulation after 2 days of incubation, while the emulsion treated with superoxide dismutase (SOD) and bovine serum albumin (BSA) changed little. In addition, the thiobarbituric acid reactive substances (TBARS) value and the content of hydroxyl radicals in the CAT group increased significantly. The preliminary research results indicated that the effect of CAT on the emulsion related to the lipid oxidation caused by the iron porphyrin group at the center of the enzyme activity. All these results indicated that CAT was not suitable for the removal of residual H2O2 in Antarctic krill oil emulsion. Moreover, it is helpful to avoid the contact of Antarctic krill oil emulsion and CAT during the processing of the krill.

DNA hypermethylation associated with the development of temperature-dependent postharvest chilling injury in peach fruit

Peach fruit is often subjected to postharvest chilling injury (CI) during long-term cold storage and the degree of CI is related to the storage temperature. Analysis of the data on softening, ethylene production and internal browning (IB) showed that CI occurred in fruit stored at or below 12 °C. Impairment of ethylene production and softening was greater in fruit stored at 0 and 5 °C and was consistent with lower expression of related critical genes. Lower malondialdehyde and hydrogen peroxide contents and enhanced hydroxyl radical contents were observed in fruit stored at 0 and 5 °C. These changes were associated with higher transcript levels of polyphenol oxidases and peroxidase, but lower expression levels of lipoxygenase, superoxide dismutase and catalase. To investigate whether DNA methylation is involved in the CI development in peach fruit, single-base resolution DNA methylome and transcriptome analysis was carried out. The DNA methylation level was higher in CI fruit and a close positive correlation was observed between the methylation level and IB index. Furthermore, for most genes involved in softening, ethylene biosynthesis and signal transduction, IB and reactive oxygen species metabolism, the expression level was found to be well correlated with low temperature-induced DNA hyper- or hypo-methylation in promoter, genebody or downstream regions. It was concluded that changes in DNA methylation in different genomic regions regulate CI associated gene expression and contribute to the development of temperature-dependent CI in postharvest peach fruit.

Exogenous methyl salicylate alleviates senescent spotting by enhancing the activity of antioxidative ascorbate-glutathione cycle in harvested ‘Sucrier’ bananas

Senescent peel spotting, a physiological disorder, develops during the latter stage of ripening which coincides with the best eating quality of ‘Sucrier’ banana fruit. It is a major constraint for banana growers and traders. The aims of this study were to evaluate the regulatory roles of methyl salicylate (MeSA) on the senescent spotting and the activity of antioxidative ascorbate glutathione (ASA-GSH) cycle in ‘Sucrier’ banana during storage. ‘Sucrier’ bananas (ripening stage 3–4) were immersed in 0 (control) and 2 mM MeSA for 30 min, then air dried and stored at 25 ± 1 °C for 6 d. After treatment, peel spotting, reactive oxygen species (ROS) production (hydrogen peroxide and hydroxyl radical contents), oxidative membrane damage (malondialdehyde and protein carbonyl contents and electrolyte leakage), enzymatic and non-enzymatic components of ASA-GSH cycle were determined. It was shown that the symptoms of peel spotting in the control group was observed on day 2 and the severity increased continuously throughout storage. The occurrence of peel spotting coincided with the marked increase in the ROS production and oxidative membrane damage. The activities of ASA-GSH cycle including ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase and glutathione reductase activities as well as ascorbate (ASA) and reduced glutathione (GSH) contents declined with an increase in the severity of peel spotting. However, MeSA treatment caused an overall increase in the activities of enzymatic and non-enzymatic antioxidants as well as ASA/dehydroascorbate and GSH/oxidized glutathione ratios for up to 5–6 d of storage. The increased activity of ASA-GSH cycle was also associated with the decreases in ROS levels, oxidative membrane damage and senescent spotting development, indicating that MeSA treatment could reduce senescent spotting of ‘Sucrier’ bananas during storage by enhancing the activity of ASA-GSH cycle leading to the induction of antioxidant defense system to overcome ROS production, oxidative damage and fruit senescence.

Study of the effect of surfactants on hydroxyl radicals in Ag–Ce–ZnO nanocomposites

In this paper, Ag–Ce–ZnO nanocomposites with average particle size of about 50 nm were prepared by direct precipitation method. In order to solve the problem of agglomeration, the nanocomposites with the average particle size of about 30 nm were obtained by treating the nanocomposites with surfactant sodium polyacrylate (PAAS). The effect of surfactant PAAS on the content of hydroxyl radicals produced by nanocomposites was determined by UV spectrophotometry and fluorescence spectrophotometry, and the effect of PAAS on the dispersion effect was obtained indirectly. The experimental results showed that the addition of surfactants’ PAAS effectively reduced the average particle size of nanocomposites, increased the content of hydroxyl radicals, and made the nanocomposites have good dispersing effect.

Вплив цистеїл-гістидил-тирозил-гістидил-ізолейцину на вміст продуктів пероксидного окиснення ліпідів та активних форм Оксигену в щурів різного віку за дії важких металів і гліфосату

Introduction. Oxidative stress plays a critical role in the pathophysiology of several diseases: liver cirrhosis, atherosclerosis, diabetes mellitus, ischemic heart disease, carcinogenesis, etc. The main mechanism of oxidative stress induced is the disturbance oxidation and reduction processes by various factors such as toxic substances, radiation, temperature, drugs. Ions of heavy metals (transition metals) lead to the production of reactive oxygen species (ROS), causing a lipid peroxidation and other main biomolecules (proteins, nucleic acids).The aim of the study – to learn the influence of peptid: cisteil-histidil-tyrosil-histidil-isoleucine on generation of active forms of oxygen the content of products of free lipid peroxidation.Research Methods. The experiment was carried out on lab nonlinear white rats – males three age periods: puberty, mature and old aging animals. The rats received the lead acetate, copper sulfate, glyphosate (in herbicide Roundup) in combined and peptide as correction agent. Subhronic lesions in rats was modelled by intragastric administration of water solution of Lead Acetate at a dose of 11 mg/kg, Copper Sulfate at a dose of 13 mg / kg, Glyphosate at a dose of 250 mg / kg. Dehlorinated drinking tap water to intact animals was added. The correction effect was research by the during 10 days intragastric administration of water solution of peptide cisteil-histidil-tyrosil- histidil-isoleucine in a dose of 9 mg / kg at 21th day of the experiment after 6 hours after toxins. The degree of lipid peroxidation was assayed by estimating the thiobarbituric acid reactive substances (TBARS) and diene conjugates (DK) in blood serum and liver homogenates by spectrophotometric method. The superoxide anion-radical content was determined by test with Nitrobluetetrazolium, hydroxyl radical content was determined by the product of oxidation of 2-deoxyribose.Results and Discussion. It was established that the production of reactive oxygen species and lipid peroxidation increase by the combined effect of glyphosate (in Roundup form herbicide), lead acetate, copper sulfate in different age rats. There was a significant increase in concentration of TBARS, diene conjugates, superoxide anionradical and hydroxyl radical. One of the most probable mechanisms of peptide: cisteil-histidil-tyrosil-histidil-isoleucine corrective activity is based on its ability to antioxidantion activity that decrease concentration of a production of reactive oxygen species and a lipid peroxidation.Conclusion. The protective effect of peptide: tsysteil-histidil-tyrosil-histidil-isoleucine on liver damages rats induced by toxicity is administration induced loss to the production of reactive oxygen species, causing a lipid peroxidation

Catalysts based on Fenton reaction for SiC wafer in chemical magnetorheological finishing

Aiming at the chemical magnetorheological finishing (CMRF) of single crystal silicon carbide (SiC) based on the Fenton reaction, concentration of hydroxyl radical produced in Fenton reaction and its influence on chemical reaction rate of SiC were detected by visible spectrophotometry, and catalytic ability of different particles was detected by the method of immersion corrosion test. The experimental results showed that surface roughness is better when the carbonyl iron powder (CIP) is used as catalyst. The lower value of pH, the higher content of hydroxyl radicals. The hydroxyl radical can react with SiC surface to form a softer SiO 2 oxide layer. The acid environment can promote Fenton reaction and the polishing effect is better, while the oxidation layer of SiC surface is converted to silicate in the alkaline environmental. The SiC after CMRF can obtain the smooth surface of the surface roughness Ra 0.0817 nm when the pH value is 9.

SDBS-assisted hydrothermal treatment of TiO2 with improved photocatalytic activity

To meet the practical application, it is still a challenge to prepare TiO2 with excellent photocatalytic performance. Therefore, in this work, TiO2 photocatalyst with enhanced sunlight-driven photocatalytic activity was facilely obtained after hydrothermal treatment of TiO2 with the assistance of sodium dodecyl benzene sulfonate (SDBS). TiO2 and SDBS-TiO2 were characterized by Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), UV–Vis diffuse reflectance spectra (DRS), scanning electron microscopy (SEM), surface photovoltage (SPV) spectroscopy and X-ray photoelectron spectroscopy (XPS), respectively. The photocatalytic performance of the photocatalysts toward Rhodamine B (RhB) discolorization was evaluated. The results display that a much higher photo-induced charge separation rate, active free radicals and surface hydroxyl radical content were produced in the SDBS-TiO2 photocatalytic system. The results further reveal that the photocatalytic performance of SDBS-TiO2 is more than two times of that of the reference TiO2.

Influence of sodium nitrite exposure on sulfhemoglobin and hydroxyl radicals in mice

Objective: To investigate the influence of sodium nitrite exposure on sulfhemoglobin and hydroxyl radicals in mice. Methods: A total of 60 mice were randomly divided into low-, middle-, and high-dose groups (the concentrations of sodium nitrite were 0.055 mg/ml, 0.110 mg/ml, and 0.220 mg/ml, respectively) and control group (treated with distilled water) , with 15 mice in each group (male/female ratio=1: 1) . A free-drink model was applied and the duration of exposure was 2 weeks. The body weight of all mice was recorded before exposure and at weeks 1 and 2 of exposure. At the end of exposure, the mice were treated with intraperitoneally injected sodium salicylate to capture the hydroxyl radicals and produce 2, 5-dihydroxybenzoic acid and 2, 3-dihydroxybenzoic acid, and high-performance liquid chromatography was used to measure their content. Spectrophotometry was used to measure the relative content of sulfhemoglobin. Results: At week 2 of exposure, the low-, middle-, and high-dose groups had significantly lower body weight than the control group (22.8±2.8 g/21.6±2.8 g/21.2±3.0 g vs 25.6±2.2 g, P<0.05) . The low-, middle-, and high-dose groups had a significantly higher total content of hydroxyl radicals than the control group[ (0.015 3±0.006 5) μg/ml, (0.016 4±0.017 2) μg/ml, and (0.062 7±0.091 0) μg/ml vs (0.009 ±0.007 3) μg/ml, P<0.05]. The relative content of sulfhemoglobin was 1.54%±0.73%, 2.22%±0.44%, and 2.80%±0.69%, respectively, in the low-, middle-, and high-dose groups, and the middle- and high-dose groups had a significant increase in the relative content of sulfhemoglobin compared with the control group (2.22%±0.44%/2.80%±0.69% vs 1.76%±0.60%, P<0.05) . The content of hydroxyl radicals was positively correlated with the relative content of sulfhemoglobin (r=0.837, P<0.05) . Conclusion: Sodium nitrite exposure can increase the content of sulfhemoglobin and hydroxyl radicals in blood, and there is a positive correlation between them.

Zinc-alleviating effects on iron-induced phytotoxicity in roots of Triticum aestivum

The mechanisms of growth inhibition and antioxidative response were investigated in wheat roots exposed to 300 μM iron together with different zinc concentrations (0, 50, and 250 μM). All Zn concentrations decreased Fe content but increased Zn content in the roots and leaves of Fe-treated seedlings. Compared with Fe stress alone, 50 or 250 μM Zn + Fe treatment stimulated root growth, and increased cell viability but decreased malondialdehyde content, which were correlated with the decreases of total and apoplastic hydrogen peroxide and superoxide anion radical (O2 ·−) content along with apoplastic hydroxyl radical content. Generation of O2 ·− in response to 10 μM diphenylene iodonium suggested that NADPH oxidase activity was lower in Zn + Fe-treated roots than in other roots. In addition, cell wallbound peroxidase, diamine oxidase, and polyamine oxidase in Fe-treated roots were insensitive to Zn addition. Further study showed the stimulation of total superoxide dismutase and glutathione reductase (GR) activities as well as apoplastic catalase, ascorbate peroxidase, and GR in Zn + Fe-stressed roots in comparison with Fe-alone-treated ones. Taken together, Zn could alleviate iron-inhibitory effect on root growth, which might be associated with the decrease of lipid peroxidation, the increase of cell viability and the reductions of reactive oxygen species generation.

DISRUPTION OF EXPRESSION OF MRNA HSP27 AND UBIQUITIN AS A MECHANISM OF ESCAPING OF JURKAT LINE TUMOR CELLS FROM APOTOSIS

The research objective is to establish the link between heat shock protein 27 and ubiquitin mRNA expression as well as Jukart tumor cell apoptosis.The method of flow cytofluorometry has been used to evaluate apoptosis realization using FITC-labeled annexin V and propidium iodide along with the amount of reactive oxygen species. Spectrofluorimetry has been applied to register the caspase-3 activity. The content of hydroxyl radicals has been determined by spectrophotometry. The level of ubiquitin and heat shock protein 27 mRNA expression has been identified using real-time PCR. Intact Jukart tumor cells and blood lymphocytes of healthy donors served the material for the research.Following the carried out research it has been found out that the fall in the amount of annexin V positive cells and the reduced caspase-3 activity were accompanied by the rise in the content of hydroxyl radicals and reactive oxygen species against the backdrop of the increased heat shock protein 27 and ubiquitin mRNA expression in Jukart tumor cells.