Maximum Protective Effect Research Articles

New progress in the treatment of chronic wound of diabetic foot

Diabetic foot is one of the serious complications of diabetic patients. It is caused by diabetes combined with different degrees of lower extremity vascular lesions and neuropathy, and the wound can not heal for a long time. The serious results can cause bone marrow infection, bone destruction, and have high disability and death rate. At present, there are various treatment methods for diabetic foot chronic wound. On the basis of internal medicine controlling blood sugar, anti infection, lowering blood lipid, improving microcirculation and nourishment nerve, the surgical method is adopted, including the debridement of the necrosis in a short time to prevent the infection from spreading; maggot biological debridement and ozone chemical debridement will promote the growth of granulation tissue while controlling infection. Skin grafting, skin flap transplantation, skin distraction closure can be used to repair soft tissue defects, or fat transplantation, platelet-rich plasma, and rich blood are used for the refractory wound after infection control. In patients with diabetic foot, the reconstruction of lower limb blood supply is beneficial to the recovery of chronic ischemic wounds. It is feasible to improve the blood supply of the lower extremities, improve the blood supply of the lower extremity artery bypass grafting, and improve the microcirculation of the peripheral vessels around the lower extremities. Lower extremity vascular bypass pressure perfusion therapy for vascular network expansion, tibia lateral moving technique for lower limb microcirculation reconstruction. For diabetic foot ulcer caused by peripheral neuropathy, such as Charcot foot, while the application of external fixator, total contact cast technology of affected foot for reducing treatment to promote wound healing; the preparation of orthopedic shoes can play a maximum protective effect on the healing of diabetic foot wound healing.

Research on the Influence of Temperature on Beech Crops Raised in Nurseries

Abstract A particularly important determining factor for the installation and development of seedlings during the early years is their ability to withstand deviations from the normal regime of the climatic elements. Beech seedlings have poor resistance to extreme climate changes. The development of seedlings during the first years can be strongly affected by extreme temperatures. During the research, it was noticed that the frosts which may occur during the second half of April and in early May, before foliation, can cause significant injuries to the plantlets. A large part of the beech seedlings appear in early spring, approximately 7 - 10 days before the foliation of beech trees. The effects of these frosts have also been felt in the nurseries located in the area of the Sovata Forestry, in the case of crops sown in the autumn of the previous year in the Isuica Nursery, situated at an altitude of 520 - 530 m, in the vicinity of Săcădat Creek, and in the case of Solar II Nursery, situated in the village Câmpul Cetaţii, at an altitude of 610 m. The latter nursery is neighbored by the trout farm from Câmpul Cetăţii to the south, by the secondary school to the west, by private residences and estates to the east and by the village road of Câmpul Cetăţii to the north. In both nurseries the emergence percentage of the crops at the end of April was over 90%. Based on the average number of seedlings emerged per area unit, the losses recorded as a result of the frosts from 3-4 May were, in the case of the Isuica Nursery, 89% on 10 May, reaching 97% towards the end of the month. Unlike in the Isuica Nursery, in the Solar II Nursery the losses due to the frost of 3 May were not uniform. The area that was least affected by frost was situated in the immediate proximity of the larch curtain and the secondary school building, where the percentage of losses did not exceed 2%. Moving away from the larch curtain, the percentage increased progressively, reaching, at about 24 m (on the diagonal of the plot), as high as 87%. This percentage was close to that of the (uniform) losses registered in the Isuica Nursery. Thus, the maximum protective effect was recorded up to a distance of about 9 km (0.75 H), where H represents the height of the larch curtain). From this distance, the protective effect exerted by the larch curtain (and the secondary school building with a height of 8 m) started to decrease. While at a distance of about 1 H, the percentage of losses was 17 %, at 1.5 H it reached 61 %, and at approx. 2 H it neared 90 %.

The synthesis of polyhydroxy sterone 2β,3α,5-trihydroxy-5α-androst-6-one and its neuroprotection

Neuroactive steroids exhibit better neuroprotective properties in vitro and in vivo, and will be a potential neuroprotective effect. In this study, polyhydroxy sterone 2β,3α,5-trihydroxy-5α- androst-6-one (YC-10) was designed and synthesized from androst-5-en-3-ol by 6 steps reactions. Its absolute structure was characterized by X-SRD and its structure was characterized by NMR, IR, and MS. Its neuroprotective action was determined by MTT assay with two models of neurotoxicity. The maximum protective effect was at a concentration of 40μM for neurotoxicity induced by glutamate, and showing better cell viability in a dose-dependent manner; Moreover it cloud significantly protect the cerebellar granule neurons against neuronal death mediated by low K + , its effective protective concentration was 50μM.

Sports in Patients with Heart Disease: What Should Be Recommended?

Sports in Patients with Heart Disease: What Should Be Recommended? Abstract. Sports is recommended in the European guidelines for the prevention and initial treatment of many cardiovascular diseases as well as the metabolic syndrome. However, the individually recommended intensity and duration of physical activity that unfolds the maximal protective effects in terms of prevention, largely differs. Indeed, a J-curve relationship with regard to exercise training has been postulated, with the assumption that too much sports is equally harmful or potentially even more harmful than too little sports. In this review, we try to answer the question of how much and which sports is optimal for cardiac patients.

A single-molecule assessment of the protective effect of DMSO against DNA double-strand breaks induced by photo-and \u03b3-ray-irradiation, and freezing

Dimethyl sulfoxide (DMSO) is widely used as a cryoprotectant for organs, tissues, and cell suspension in storage. In addition, DMSO is known to be a useful free radical scavenger and a radio-protectant. To date, many in vitro assays using cultured cells have been performed for analysing the protective effect of DMSO against genomic DNA damage; however, currently it has been rather difficult to detect DNA double strand breaks (DSBs) in a quantitative manner. In the present study, we aimed to observe the extent of DNA damage by use of single molecular observation with a fluorescence microscope to evaluate DSBs induced by photo- and γ-ray-irradiation, or freeze/thawing in variable concentrations of DMSO. As a result, we found that 2% DMSO conferred the maximum protective effect against all of the injury sources tested, and these effects were maintained at higher concentrations. Further, DMSO showed a significantly higher protective effect against freezing-induced damage than against photo- and γ-ray-irradiation-induced damage. Our study provides significant data for the optimization of DNA cryopreservation with DMSO, as well as for the usage of DNA as the protective agent against the injuries caused by active oxygen and radiations.

ADSORPTION OF IONS OF NICKEL (II) FROM WATER SOLUTIONS WITH CARBON ADSORBENTS

For citation:Dudarev V.I., Irinchinova N.V., Filatova E.G. Adsorption of ions of nickel (II) from water solutions with carbon adsorbents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 75-80.Adsorption methods of cleaning remains beyond comparison for deep extraction of heavy metal ions from dilute solutions. Their practical application allows achieving the high efficiency of wastewater treatment with minimal impact on the environment. It is known that nickel is one of carcinogenic elements. Thus, free nickel ions (II) are twice toxic than complex compounds. The maximum content of nickel ion (II) at the production of spent electroplating solutions is 50 mg/l, in washing waters – from 2 to 5 mg/l. In this paper we studied the adsorption capacity of carbon adsorbents IPI-T, synthesized from waste phenol-formaldehyde resin with respect to the nickel ions (II). Carbon аdsorbents IPI-T are black granules of irregular shape with an average particle size from 2 to 5 mm, and a surface area of 480 m2/g. Adsorption equilibrium time in static conditions corresponding to the constancy of the concentration of heavy metal ions in solution was four hours. A study of the adsorption capacity of carbon adsorbents IPI-T was performed at pH of 9.5. The adsorption process accompanied by the slight decrease in pH. Isotherms were build according to the results of research of adsorption at different temperatures. The shape of the isotherms obtained corresponds to poly-molecular adsorption. The resulting isotherms were processed using adsorption models of BET and Dubinin-Radushkevich. It was shown that the adsorption process model is best described by BET. Model Dubinin-Radushkevich was used to calculate the free energy of adsorption. The value of the free energy of adsorption indicates that the binding of nickel ion (II) has a physical nature. It was found that with the temperature increasing the adsorption capacity of carbon adsorbents IPI-T decreases. The dynamic activity of the adsorbent was characterized by the time of beginning of pass of the adsorbate till «breakthrough». Maximum protective effect of the adsorbent was 5 hours, and it was recovered 150 mg of nickel ions (II). The effectiveness of wastewater treatment of galvanic production from heavy metal ions was not less than 98%.

Protective Role of Postbiotic Mediators Secreted by Lactobacillus rhamnosus GG Versus Lipopolysaccharide-induced Damage in Human Colonic Smooth Muscle Cells.

Some beneficial effects of probiotics may be due to secreted probiotic-derived factors, identified as "postbiotic" mediators. The aim of this study was to evaluate whether supernatants harvested from Lactobacillus rhamnosus GG (LGG) cultures (ATCC53103 strain) protect colonic human smooth muscle cells (HSMCs) from lipopolysaccharide (LPS)-induced myogenic damage. LGG was grown in de Man, Rogosa, Share medium at 37°C and samples were collected in middle and late exponential, stationary, and overnight phases. Supernatants were recovered by centrifugation, filtered, and stored at -20°C. The primary HSMCs culture was exposed for 24 hours to purified LPS of a pathogen strain of Escherichia coli (O111:B4) (1 μg/mL) with and without supernatants. Postbiotic effects were evaluated on the basis of HSMCs morphofunctional alterations and interleukin-6 (IL-6) production. Data are expressed as mean±SE (P<0.05 significant). LPS induced persistent, significant, 20.5%±0.7% cell shortening and 34.5%±2.2% decrease in acetylcholine-induced contraction of human HSMCs. These morphofunctional alterations were paralleled to a 365.65%±203.13% increase in IL-6 production. All these effects were dose-dependently reduced by LGG supernatants. Supernatants of the middle exponential phase already partially restored LPS-induced cell shortening by 57.34%±12.7% and IL-6 increase by 145.8%±4.3% but had no effect on LPS-induced inhibition of contraction. Maximal protective effects were obtained with supernatants of the late stationary phase with LPS-induced cell shortening restored by 84.1%±4.7%, inhibition of contraction by 85.5%±6.4%, and IL-6 basal production by 92.7%±1.2%. LGG-derived products are able to protect human SMCs from LPS-induced myogenic damage. Novel insights have been provided for the possibility that LGG-derived products could reduce the risk of progression to postinfective motor disorders.

Comparison of the effects of lipoic acid and glutathione against cisplatin-induced ototoxicity in auditory cells

ObjectivesThe aims of this study were to examine lipoic acid (LA)- or glutathione (GSH)-mediated protection against cytotoxicity following cisplatin exposure in HEI-OC1 auditory cells and measure the potential of LA and GSH to scavenge reactive oxygen species (ROS). This study also compares their protective effects and discusses the determination of a preventive or therapeutic dose. MethodsHEI-OC1 cells were pretreated with LA or GSH for 24 h and then exposed to 15 μM cisplatin for 48 h. The resulting cytotoxicity was measured using a cell counting kit-8, and intracellular ROS level was measured using flow cytometry. The protective or anti-ROS effects of LA and GSH were compared. Measurement of caspase 3, 8, 9 activity and Western blot analysis of PARP were performed. ResultsPretreatment with LA at 300 μM and GSH at 3 mM protected HEI-OC1 cells against cisplatin-induced cytotoxicity and significantly reduced the cisplatin-induced increase in ROS. LA showed a significantly more effective protection against cisplatin-induced ototoxicity compared to that shown by GSH (85.4% vs. 73.1% cell viability). Both LA and GSH showed the maximal protective effect at different concentrations in normal or cisplatin-induced cytotoxic conditions. The preventive or therapeutic dose for harmful conditions is quite different for the two drugs and needs careful adjustments. ConclusionThis comparative study on the protective effects of LA and GSH against cisplatin-induced ototoxicity in an auditory cell line posed many challenges. Although LA and GSH showed a significant protective effect against cisplatin, the LA's effect was superior. The concentration at which the maximal protective effect of LA or GSH was noted was 3 times higher in cytotoxic conditions than in normal conditions, which suggests the need for drug dose adjustments based on the purpose (preventive or therapeutic).

Trehalose protects Mn-depleted photosystem 2 preparations against the donor-side photoinhibition

Recently, it has been shown that the addition of 1M trehalose leads to the increase of the rate of oxygen photoconsumption associated with activation of electron transport in the reaction center of photosystem 2 (PS2) in Mn-depleted PS2 membranes (apo-WOC-PS2) [37]. In the present work the effect of trehalose on photoinhibition of apo-WOC-PS2 preparations (which are characterized by a high sensitivity to the donor side photoinhibition of PS2) was investigated. The degree of photoinhibition was estimated by the loss of the capability of exogenous electron donor (sodium ascorbate) to reactivate the electron transport (measured by light-induced changes of chlorophyll fluorescence yield (∆F)) in apo-WOC-PS2. It was found that 1M trehalose enhanced the Mn2+-dependent suppression of photoinhibition of apo-WOC-PS2: in the presence of trehalose the addition of 0.2μM Mn2+ (corresponding to 2 Mn2+ per one reaction center) was sufficient for an almost complete suppression of the donor side photoinhibition of the complex. In the absence of trehalose it was necessary to add 100μM Mn2+ to achieve a similar result. The effect of trehalose was observed during photoinhibition of apo-WOC-PS2 at low (15μmolphotons−1m−2) and high (200μmolphotons−1m−2) light intensity. When Mn2+ was replaced by other PS2 electron donors (ferrocyanide, DPC) as well as by Ca2+ the protective effect of trehalose was not observed. It was also found that 1M trehalose decreased photoinhibition of apo-WOC-PS2 if the samples contained endogenous manganese (1–2 Mn ions per one RC was enough for the maximum protection effect). It is concluded that structural changes in PS2 caused by the addition of trehalose enhance the capability of photochemical reaction centers of apo-WOC-PS2 to accept electrons from manganese (both exogenous and endogenous), which in turn leads to a considerable suppression of the donor side photoinhibition of PS2.

Immunization Against Specific Fragments of Neurotrophin p75 Receptor Protects Forebrain Cholinergic Neurons in the Olfactory Bulbectomized Mice

Alzheimer’s disease (AD) is characterized by progressive cognitive impairment associated with marked cholinergic neuron loss and amyloid-β (Aβ) peptide accumulation in the brain. The cytotoxicity in AD is mediated, at least in part, by Aβ binding with the extracellular domain of the p75 neurotrophin receptor (p75NTR), localized predominantly in the membranes of acetylcholine-producing neurons in the basal forebrain. Hypothesizing that an open unstructured loop of p75NTR might be the effective site for Aβ binding, we have immunized both olfactory bulbectomized (OBX) and sham-operated (SO) mice (n = 82 and 49, respectively) with synthetic peptides, structurally similar to different parts of the loops, aiming to block them by specific antibodies. OBX-mice have been shown in previous studies, and confirmed in the present one, to be characterized by typical behavioral, morphological, and biochemical AD hallmarks, including cholinergic deficits in forebrain neurons. Immunization of OBX- or SO-mice with KLH conjugated fragments of p75NTR induced high titers of specific serum antibodies for each of nine chosen fragments. However, maximal protective effects on spatial memory, evaluated in a Morris water maze, and on activity of choline acetyltransferase in forebrain neurons, detected by immunoreactivity to specific antibodies, were revealed only for peptides with amino acid residue sequences of 155–164 and 167–176. We conclude that the approach based on immunological blockade of specific p75NTR sites, linked with the cytotoxicity, is a useful and effective tool for study of AD-associated mechanisms and for development of highly selective therapy of cholinergic malfunctioning in AD patients.

Assessment of Protective Properties of the Recombinant Complex of the Outer Membrane Protein F and the Toxoid of Pseudomonas aeruginosa

Pseudomonas aeruginosa induces the complications after burns, injuries, surgical interventions and appears to be one of the main causative agents of nosocomial infections. This pathogen has the high resistance to the antibacterial preparations, therefore the immunoprophylaxis is considered as one of the major approaches to reduce Pseudomonas infection. Objective: The aim of our investigation is to study the protective properties of the recombinant complex of the outer membrane protein F (OprF) and a non-toxic variant of the exotoxin A (toxoid) against Pseudomonas infection. Methods: The recombinant proteins which contained the additional histidine residues were synthesized into Escherichia coli with isopropyl-βD-thyogalactopyranoside (IPTG). The recombinant proteins were purified by affinity chromatography on Ni-Sepharose. The preparations of recombinant proteins were injected intraperitoneally into the mice. Aluminum hydroxide was used as an adjuvant. For an experimental infection in mice, animals were challenged intraperitoneally by a live virulent culture of P. aeruginosa (PA-103 strain). Results: The best protective effect for the complex containing 25 μg OprF and 50 μg toxoid was identified when we used the double immunization of mice (Index of efficiency of the protective properties in this case was 4.0). Indexes of efficiency of separated recombinant proteins which were injected twice in the same doses were 2.0 for OprF и 2.3 for toxoid. The triple immunization of animals was inefficient for separated recombinant proteins in the same doses. The injection of doses which were lowered twice (12.5 μg for OprF and 25 μg for toxoid) resulted in increased survival of mice immunized by individual proteins (indexes of efficiency: 3 for OprF and и 3,5 for toxoid). However when we administered to the complex of proteins with the same doses Index of efficiency was 2.8. Conclusion: It was shown that the maximum protective effect in a short time is achieved by the combination of double immunization and the mixture of the recombinant proteins OprF and the 25 and 50 μg doses of recombinant toxoid .

Qualitative and quantitative changes of potato tuber proteome under the influence of signal molecules and infection with Phytophthora infestans

The influence of signal molecules (jasmonic acid, phytoprostanoid oxylipins, lipopeptides of the Bacillus subtilis 26D bacterium) on the Solanum tuberosum L. potato tuber proteome was studied upon infection with the Phytophtora infestans (Mont.) de Bary phytophthorosis causative agent. Processing by signaling molecules decreased the degree of oomycete development on potato discs and caused changes in the total spectrum of soluble proteins in a pH range of 6.0–7.0 and 7.5–8.7. Differences in the differential expression of 39 polypeptides under the influence of signal molecules and infection with a pathogen were detected. It was demonstrated that the maximal protective effect upon the potato tuber infection with a pathogen is caused by the induction of protective proteins in tissues with the following values of the molecular weight/pI ratio: 24/5.8, 75/6.45, 68/6.45, 19/6.5, 69/6.3. The presence of qualitative and quantitative changes in the expression of individual proteins indicated a differential mechanism of the effect of signal molecules on the protective potential of plant cells.

Chemical modification of iron particles in mechanical activation with polydienes

Ultrafine iron particles prepared via mechanical activation in a planetary ball mill in polydiene solutions with surface-active substances (SASs) are studied in this work. It is shown that carbides are disposed in the particle bulk, whereas an organic layer with modified (oxidized) polymer molecules and SASs is formed at the surface of particles. Adsorption of polydienes on the particle surface is due to alcohol and carboxyl groups. It is established that modification of iron particles with polybutadiene leads to the formation of a polymeric film with a maximum protective effect.

&amp;lt;i&amp;gt;In Vitro&amp;lt;/i&amp;gt; Antioxidant Properties of Phloretin—An Important Phytocompound

Reactive oxygen species [ROS] cause oxidative damage to the tissues and protection from such damages is provided by endogenous and exogenous antioxidants. Much research work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. So, this study was aimed to evaluate the in vitro antioxidant capacity of one of the phenolic compounds phloretin. Phloretin was used at four different concentrations like 20, 40, 60 and 80 μg/ml to determine the antioxidant activity by different methods such as total antioxidant capacity, reducing power, DPPH radical scavenging, superoxide anion radical scavenging and metal chelating assays. In addition to that the ascorbic acid was used as reference compound. The results showed that the phloretin displayed potent in vitro antioxidant capacity. It was able to scavenge different in vitro free radicals in all tested concentrations. Among the different concentrations, 80 μg of phloretin has maximum activity when compared to other concentrations in all in vitro antioxidant assays. High antioxidant property and maximum protective effect of phloretin were observed in a concentration dependent manner. The results were expressed as IC50 value. The lowest IC50 value indicates the highest scavenging activity. The reducing power of the phloretin was also found in concentration dependent. According to the results of this study, we concluded that the phloretin possesses antioxidant property. Therefore, phloretin is a powerful antioxidant phytocompound which can protect biological systems against the oxidative stress. From this study, we suggest that the phloretin may be used as a dietary natural antioxidant supplement for preventing free radical related diseases.

Mitigating effect of Indian propolis against mitomycin C induced bone marrow toxicity.

A major drawback with cancer chemotherapy is its severe toxic effects on non-target tissues. Assessment of natural products for their protective effect against anticancer drugs-induced toxicity is gaining importance in cancer biology. The present study was aimed at assessing the protective effect of hydroethanolic extract of Indian propolis (HEIP) against mitomycin C (MMC)-induced genotoxicity and cytotoxicity. Swiss albino mice were injected with various doses of HEIP (100, 200, 300, 400, 600 and 800mg/kg b. wt., i.p) 1h prior to MMC (8mg/kg, i.p.) injection. The geno- and cyto-toxicities were evaluated in mice by performing bone marrow micronucleus and TUNEL assays. In vitro antioxidant and lipid peroxidation inhibitory assays were carried out to understand the mechanism of the protective effects. The significant increase in the frequency of micronculeated cells (12.51±0.48), apoptotic cells (23.43±1.86) and reduction in P/N ratio (0.69±0.04) compared with control indicated the potential geno- and cytotoxic effects of MMC in bone marrow. Pretreatment with HEIP resulted in the significant recovery of the toxic effects induced by MMC. HEIP at 400mg/kgb. wt. was found to be the optimum dose imparting the maximum protective effects. The in vitro antioxidant and lipid peroxidation inhibitory assays suggest that the extract possesses substantial free radical scavenging activities. In conclusion, HEIP possesses substantial geno- and cyto-protective properties against MMC, which could be mediated through efficient free radical scavenging and inhibitory effect on lipid peroxidation.

OP‐3 THE PROTECTIVE ROLE OF LACTOBACILLUS RHAMNOSUS GG‐DERIVED FACTORS AGAINST LPS‐INDUCED DAMAGE OF HUMAN COLONIC SMOOTH MUSCLE CELLS.

Impaired gut barrier function has been reported in some functional gastrointestinal (GI) disorders.Evidences suggest that gut microbiota affects GI motility in particular Lactobacillus species elicits anti‐inflammatory activity and exerts protective effects on damage induced by pathogen Gram negative‐derived lipopolysaccharide(LPS). LPS produced an oxidative imbalance in human colonic smooth muscle cells (SMC) that persists after LPS‐washout and contributes to SMC morphofunctional alterations. Aim: evaluate if supernatants harvested from LGG cultures protect SMC from LPS‐induced myogenic damage.Methods:L. rhamnosus GG (ATCC 53103 strain) was grown in MRS medium and samples were collected from bacterial cultures in middle exponential phase, in early, in middle and late stationary phase (overnight).Supernatants were recovered, filtered and stored at ‐20 °C. Highly pure human SMC culture was then exposed for 24 h to highly purified LPS (1 μg/ml) of E.coli (O111:B4) in the absence and presence of the supernatants.Their effects were evaluated on LPS‐induced SMC morphofunctional alterations and pro‐inflammatory IL‐6 production. Data are expressed as mean ± SE (p &lt; 0.05 significant).Results:LPS induced persistent significant 20.7% ± 1.2 cell shortening and 35.2% ± 2.6 decrease in contraction of human colonic SMC. These alterations were paralleled to a 238.5% ± 82.5 increase in IL‐6 production.These effects disappeared in the presence of LGG‐supernatants, following a progression related to LGG growth curve phases. Supernatants collected in the middle exponential phase already significantly partially restored LPS‐induced cell shortening by 43.4% ± 10.2 and IL6 increase by 47.6% ± 13.1 but had no effect on LPS‐induced inhibition of contraction. Supernatants collected later, in the early and middle stationary phase, further counteract LPS‐induced damage, including inhibition of contraction. Maximal protective effects were observed with supernatants of the late stationary phase where LPS‐induced cell shortening was reversed by 86% ± 4.7, inhibition of contraction by 98.2% ± 1.8 and IL6 basal production by 91.3% ± 0.6.Conclusions: LGG secreted products are substances/byproducts able to directly protect human SMC from LPS‐induced myogenic damage. Novel insights are then provided about the possibility that LGG‐derived products could reduce the risk of progression to a post‐infective motor disorder.

PP48 - Prevention of peroxynitrite-induced nitration and oxidation by nitroxides

Peroxynitrite, formed in vivo in a reaction between nitric oxide and superoxide radical anion, is a compound of profound pathophysiological importance. The formation of peroxynitrite is intensified in many diseases, including neurodegenerative ones, and its reactions appear to contribute to the development of these diseases. Therefore, prevention of reactions of peroxynitrite may be useful in disease prevention and treatment. The aim of this study was to study the ability of nitroxides of various structures to prevent reactions of nitration and oxidation of model compounds and bovine serum albumin. Eleven nitroxides were used: 2,2,6,6-tetramethylpiperidine (TEMPO), 4-hydroxy-TEMPO, 4-amino-TEMPO, 4-oxo-TEMPO, 4-carboxy-TEMPO, 4-cyano-TEMPO, 4-methoxy-TEMPO, 4-acetamido-TEMPO, 4-nonylamido-TEMPO, 3-carbamoyl-PROXYL and 3-carbamoyl-dehydroPROXYL. Nitroxides were most effective in preventing peroxynitrite-induced decay of fluorescein (2 µM), conditioned by fluorescein nitration (IC50 of 40.0 ± 0.4 nM, 59.8 ± 0.6 nM and 64.4 ± 1,2 nM for the most effective nitroxides, viz. 4-hydroxy-TEMPO, 4-acetamido-TEMPO and 4-amino-TEMPO, respectively, and 3.72 ± 0.05 µM for the least effective 4-nonylamido-TEMPO). Nitroxides had a biphasic effect on the oxidation of dihydrorhodamine 123 (1 µM) by peroxynitrite, both low and high concentrations having a prooxidant effect. A protection window was observed for micromolar concentrations of nitroxides (maximal protective effect at 17.3 ± 2.3, 40 and 50.3 ± 20.7 µM for TEMPO, 4-hydroxy-TEMPO and 4-amino-TEMPO, respectively and > 400 for Pirolin and 4-nonylamido-TEMPO, the extent of maximal protection being 38-90%. Nitroxides (5 nM – 500 µM) were totally ineffective in preventing peroxynitrite-induced thiol oxidation of bovine serum albumin. These results demonstrate that nitroxides are more effective in preventing nitration than oxidation reactions.

Изучение промышленных композиций серии СОНКОР в качестве ингибиторов коррозии малоуглеродистой стали в нейтральных сероводородсодержащих средах

Electrochemical and corrosion behavior of mild steel in neutral media containing hydrogen sulfide has been investigated by weight-loss and electrochemical methods and protective effect of industrial compositions SONKOR has been determined. It has been shown that in 3% NaCl compositions SONKOR have weak protective effect but it increases greatly in presence of hydrogen sulfide in the solution. At concentration of H2S = 0,6 gram per liter maximal protective effect has SONKOR 9801 (85,57%) and SONKOR 9920А (81,97%). Inhibitors SONKOR 9021С (70,82%), 9510А(73,11%) and 9701(67,87%) show less protective effect.

The ability of cells to adapt to low-oxygen conditions is associated with glutathionylation of Na,K-ATPase

The decrease in the oxygen content of tissues, which is observed in a number of pathological processes, inevitably leads to damage. One of the main causes of cell damage and death in hypoxia is the failure of the systems that maintain the ionic balance. Na,K-ATPase is the main ion-transporting protein in the plasma membrane of animal cells, and its inhibition at low concentrations of oxygen is one of the earliest and most critical events for cell viability. Scientists are currently conducting an active search for regulators of Na,K-ATPase activity. Cardiac glycosides traditionally used for this purpose induce severe side effects, which necessitates the search for alternative inhibitors of Na,K-ATPase. We have previously found that glutathionylation of the Na,K-ATPase catalytic subunit leads to a complete inhibition of the enzyme. The present study demonstrates that the substances that increase the level of glutathionylation in Na,K-ATPase, namely, ethyl glutathione (et-GSH), oxidized glutathione (GSSG), and N-acetylcysteine (NAC), enhance cell survival under low-oxygen conditions, prevent ATP depletion, and normalize the redox status of the cells. The following concentration range in which these substances have the maximum protective effect and no pronounced cytotoxic properties was determined to be as follows: 0.2–0.5 mM et-GSH, 0.2–1 mM GSSG, and 10–15 mM NAC. These results demonstrate the prospects of developing methods of protecting tissues from damage under low-oxygen conditions that are based on changes in Na,K-ATPase glutathionylation.

PCramoll and rCramoll as New Preventive Agents against the Oxidative Dysfunction Induced by Hydrogen Peroxide.

Oxidative stress plays an important role in the induction of cell death and is associated with various pathologic disorders; therefore, the search for natural products that attenuate the effects produced by oxidant agents is greatly increased. Here, the protective effects of native lectin from Cratylia mollis seeds (pCramoll) and recombinant Cramoll 1 (rCramoll) against H2O2-induced oxidative stress in Vero cells were evaluated. Both lectins significantly attenuated the H2O2-induced cytotoxicity in a concentration-dependent way. The maximum protective effects were 96.85 ± 15.59% (rCramoll) and 59.48 ± 23.44% (pCramoll). The Live/Dead analysis showed a reduction in the percentage of dead cells from 65.04 ± 3.29% (H2O2) to 39.77 ± 2.93% (pCramoll) and 13.90 ± 9.01% (rCramoll). The deleterious effects of H2O2 on cell proliferation were reduced to 10.83% (pCramoll) and 24.17% (rCramoll). Lectins treatment attenuated the excessive superoxide production, the collapse of the mitochondrial membrane potential, and the lysosomal and DNA damage in H2O2-treated cells. In conclusion, our results suggest that pCramoll and rCramoll blocked H2O2-induced cytotoxicity through decreasing reactive oxygen species, restoring the mitochondrial potential, preventing the lysosomal damage and DNA fragmentation, and thus promoting cell survival and proliferation.