Low Concentrations Of Hydrogen Peroxide Research Articles

Oxidative stress induces tau hyperphosphorylation via MARK activation in neuroblastoma N1E-115 cells.

Reactive oxygen species are considered a cause of neuronal cell death in Alzheimer's disease (AD). Abnormal tau phosphorylation is a proven pathological hallmark of AD. Microtubule affinity-regulating kinases (MARKs) regulate tau-microtubule binding and play a crucial role in neuronal survival. In this study, we hypothesized that oxidative stress increases the phosphorylation of Ser262 of tau protein through activation of MARKs, which is the main reason for the development of AD. We investigated the relationship between tau hyperphosphorylation on Ser262 and MARKs in N1E-115 cells subjected to oxidative stress by exposure to a low concentration of hydrogen peroxide. This work builds on the observation that hyperphosphorylation of tau is significantly increased by oxidative stress. MARKs activation correlated with tau hyperphosphorylation at Ser262, a site that is essential to maintain microtubule stability and is the initial phosphorylation site in AD. These results indicated that MARKs inhibitors might serve a role as therapeutic tools for the treatment of AD.

页岩气田回注水中低浓度过氧化氢安全风险研究

页岩气田回注水中低浓度过氧化氢安全风险研究

Multifunctional tadpole-like bimetallic nanoparticles realizes synergistic sterilization with chemical kinetics and photothermal therapy

Bacterial infection has become a global health issue. The misuse of antibiotics has been resulting in increased drug resistance and bioaccumulation. Therefore, developing a highly safe antibacterial agent, with high antibacterial performance is demanding. Inspired by the natural motors performing automated tasks in complicated living environments, we demonstrate tadpole-like nanoparticles (TNPs) with several functions, including high photothermal conversion efficiency, peroxidase-like catalytic activity, glutathione peroxidase-like activity, and catalase-like activity. TNPs produce hydroxyl radical (•OH) at an extremely low concentration of hydrogen peroxide of 0.006%, which can damage bacterial cell membranes, proteins, and DNA. Moreover, the glutathione peroxidase-like activity disrupts the anti-oxidative mechanism of bacteria and improves the permeability of the cell membranes, consequently enhancing the killing effect of ROS. In addition, TNPs possess tadpole-like asymmetry to overcome Brownian motion, demonstrating strong directional motion propelled by O2. The in vivo experiments indicate that TNPs could also shorten the inflammatory period and promote angiogenesis, making them a very promising antibacterial agent.

Effectiveness of Hydrogen Peroxide Concentrations on Bleaching and Tooth Sensitivity - A Systematic Review

Background In this study, the literature was systematically reviewed to investigate the effect of hydrogen peroxide concentrations on bleaching effect and tooth sensitivity.Data Sources: Electronic databases were screened, and hand searched. Searched electronic databases are PubMed, Scopus, Cochrane Library, Ovid Medline, Elsevier science direct, Wiley online library, Grey literature, Embase.Materials and Methods: A systematic review on controlled clinical trials MeSH terms used are (hydrogen peroxide) AND (bleaching) AND (tooth sensitivity). A trial on the bleaching effect and tooth sensitivity with various hydrogen peroxide concentrations were included. PRISMA guidelines were followed, and the PICO model was used. Cochrane risk assessment tool for randomized controlled trials was used.Results: A total of 5 articles fulfilled the inclusion criteria. The analysis showed that high hydrogen peroxide concentration has a better bleaching effect accompanied by tooth sensitivity. Low hydrogen peroxide concentration also has a bleaching effect slightly minimal from the former, followed by less tooth sensitivity.Conclusion: This study concludes that the hydrogen peroxide with higher concentration is effective in bleaching and with lower concentration is less likely to produce tooth sensitivity

Integration of Photo‐Fenton Reaction and Membrane Filtration using Lignin@t‐FeC2O4/g‐C3N4 Nanofibers Toward Accelerated Fe(III)/Fe(II) Cycling and Sustainability

AbstractPhotocatalysis water treatment without artificial energy is cost‐effective, waste‐free and sustainable. Coventional powder photocatalysts have tiny contact surfaces, low catalytic efficiency, and are difficult to recycle and reuse, restricting their usage. Herein, a Lignin@t‐FeC2O4/g‐C3N4 material is developed by engineering hollow quadrangle t‐FeC2O4 and g‐C3N4 nanosheets on lignin membranes through facile impregnation coating and precipitation reaction. Fast mass transport, catalytic activity and accessibility characterize hollow tetragonal FeC2O4·2H2O. TEM, SEM and FTIR show that lignin binds t‐FeC2O4 and g‐C3N4. The g‐C3N4 nanosheets are uniformly wrapped on the surface of lignin fibers, and t‐FeC2O4 is loaded between them. This structure increases visible light absorption and active site‐contaminant contact. The chain reaction produces extremely active hydroxyl radicals from hydrogen peroxide because the Lignin@t‐FeC2O4/g‐C3N4 modules are rich inFeII, according to XPS. Transient photocurrent response curves and electrochemical impedance spectroscopy suggest a promoted charge migration and isolation at the redox reaction interface in the Lignin@t‐FeC2O4/g‐C3N4 system. As a result, Lignin@t‐FeC2O4/g‐C3N4 degrades 99% Rhodamine B within 40 minutes, and this performance is stable even under difficult conditions, such as low hydrogen peroxide concentration and high pH. This study combines lignin membranes with the photo‐Fenton reaction, and thus provides new concept for the development and application of membranes and photocatalysis.

Conditioned medium of mesenchymal stem cells pretreated with H2O2 promotes intestinal mucosal repair in acute experimental colitis

Mesenchymal stem cells (MSCs) are a new therapeutic strategy for inflammatory bowel disease (IBD), and their efficacy has been widely recognized. However, there are still some challenges in cell therapy, including stable cell passage, laboratory conditions for cell culture, high-cost burden, and poor transplantation. The conditioned medium (CM) of MSCs is considered be an excellent alternative to cell transplantation, but the paracrine group in MSC-CM is limited in variety and low in concentration, which cannot meet the therapeutic needs of injured tissues and needs to be optimized. Pretreatment with low concentration of hydrogen peroxide (H2O2) can not only protect cells from oxidative damage, but also play a role similar to growth factors and regulate the physiological function of stem cells, to obtain an improved conditioned medium. To determine the optimal protocol for pretreatment of MSCs with H2O2, and to study the efficacy and potential mechanism of MSC-CM pretreated with H2O2 on Dextran Sulfate Sodium (DSS)-induced acute experimental colitis. MSCs were exposed to different concentrations of H2O2, and the optimal H2O2 pretreatment conditions were determined by evaluating their critical cell functional properties. H2O2-pretreated MSC-CM was transplanted into experimental mouse colitis by enema at 2, 4, and 6 days in modeling, and the changes of colonic tissue structure, the levels of inflammation and oxidative stress, the molecular changes of Nrf2/Keap1/ARE axis, and the related indicators of apoptosis in colonic epithelial cells were observed in each group. In vitro, Pretreated MSCs with 25 μM H2O2 significantly enhanced cell proliferation, migration, and survival, but had no effect on apoptosis. In vivo, MSC-CM treatment decreased apoptosis and extracellular matrix deposition, and maintained the mechanical barrier and permeability of colonic epithelial cells in experimental mouse colitis. Mechanistically, H2O2-pretreated MSC-CM against reactive oxygen species (ROS) production and MDA generation, accompanied by increases in components of the enzymatic antioxidant system includes SOD, CAT, GSH-PX, and T-AOC, which is through the up-regulation of the Nrf2, HO-1, and NQO-1 antioxidant genes. Our data confirmed that 25 μM H2O2 pretreated MSC-CM treatment could effectively improve intestinal mucosal repair in experimental colitis, which may be achieved by activating Nrf2/Keap1/ARE pathway.

A novel eco-friendly foaming technique for developing sustainable glass foams from the waste glass

The complex waste glass (WG) coming from the automotive vehicle industry has very low recycling potential and goes mainly to landfills. This research aims to develop a sustainable and eco-friendly method to prepare lightweight glass foams using this waste. Glass foams are porous, lightweight materials and are extensively used in various industry sectors. Gel-casting technique is known as an eco-friendly method for making glass foams by vigorous mechanical foaming. In gel-casting, the pore structure of the foam is initially stabilized by gelation of alkali-activated precursors and then strengthened by viscous flow sintering. However, the gelation process requires a prolonged activation and precuring processes of precursors at a raised temperature which is not energy-efficient. Therefore, this research aimed to reduce the gelation time and improve the pore characteristics in glass foams by a novel combined mechanical and chemical foaming technique. After quick alkali-activation of precursors and foaming, the hardened glass foams were sintered at 700–800°C temperatures. It is concluded that the lengthy gelation process can be replaced by quick activation and combined foaming technique to develop desirable pore characteristics. The low-speed mechanical foaming imposes low shearing stress on the activated paste, which reduces pore coalescing. Additionally, chemical foaming by low-concentration hydrogen peroxide reduces anisotropic pore formation. Consequently, the pore structure in glass foam improves. The proposed eco-friendly foaming method is useful for producing glass foams in large scale with desirable density (300–400 kg/m3), thermal conductivity (<0.10 W/(mK)) and compressive strength (∼2 MPa).

Yap1-mediated Flr1 expression reveals crosstalk between oxidative stress signaling and caffeine resistance in Saccharomyces cerevisiae.

Caffeine, a methylxanthine derivative, affects various physiological conditions such as cell growth, proliferation, and energy metabolism. A genome-wide screening for genes required for caffeine resistance in Schizosaccharomyces pombe revealed several candidates, including Pap1 and downstream target genes involved in caffeine efflux. We found that Yap1, a budding yeast AP-1 homolog required for oxidative stress response, has a caffeine tolerance function. Although the Yap1 mutant is not sensitive to caffeine, overexpression of Yap1 renders cells resistant to high concentrations of caffeine. Caffeine sensitivity of mutants lacking two multidrug transporters, Pdr5 or Snq2, is completely recovered by Yap1 overexpression. Among Yap1-dependent target genes, FLR1, a fluconazole-resistant gene, is necessary but not sufficient for caffeine tolerance. Low concentrations of hydrogen peroxide induce Yap1 activation, which restores cell viability against caffeine toxicity. Intriguingly, oxidative stress-mediated cellular adaptation to caffeine toxicity requires Yap1, but not Flr1. Moreover, caffeine is involved in reduction of intracellular reactive oxygen species (ROS), as well as mutation rate and Rad52 foci formation. Altogether, we identified novel reciprocal crosstalk between ROS signaling and caffeine resistance.

A protocol for efficient micropropagation of rare orchid Vanda brunnea Rchb.f.

• The first effective micropropagation protocol for the rare orchid Vanda brunnea. • ORCHIMAX multiplication medium has a subsequent effect on the acclimatization stage. • Brassinolide (BL) can relieve the damaging effects of stress during acclimatization. Orchids are one of the most popular groups of ornamental plants, and growing demand for them forces the horticultural industry to increase their production. This can be effectively done by in vitro propagation. This study focued on the development of an efficient protocol for in vitro propagation of a rare orchid species, Vanda brunnea (syn. Vanda henryi Schltr.). Two media, ORCHIMAX and Murashige and Skoog (MS) were tested, with or without 0.5 mg·L −1 benzyladenine (BA). Acclimatization of microplants to ex vitro conditions was done using water, 0.05% brassinolide (BL), or 1% abscisic acid (ABA). The best regeneration (100%, 6 microplants/explant) was observed on the ORCHIMAX medium (regardless of the BA presence). At the acclimatization stage, a lower stomatal conductance was observed in microplants regenerating on ORCHIMAX medium and treated with 0.05% BL. Plants regenerating on ORCHIMAX had a lower hydrogen peroxide content and a higher catalase activity than regenerants from the MS. In general, the lowest peroxide level and the highest catalase activity were found in microplants treated with BL which evidently contributed to the reduction of the oxidative stress at the acclimation stage. This resulted in 100% survival rate and a highlly efficient method for micropagation of this species.

Stress-related expression of the chloroplast EGY3 pseudoprotease and its possible impact on chloroplasts’ proteome composition

The EGY3 is a pseudoprotease, located in the thylakoid membrane, that shares homology with the family of site-2-proteases (S2P). Although S2P proteases are present in the cells of all living organisms, the EGY3 was found only in plant cells. The sequence of the pseudoprotease is highly conserved in the plant kingdom; however, little is known about its physiological importance. Results obtained with real-time PCR indicated that the expression of the EGY3 gene is dramatically induced during the first few hours of exposure to high light and high-temperature stress. The observed increase in transcript abundance correlates with protein accumulation level, which indicates that EGY3 participates in response to both high-temperature and high light stresses. The lack of the pseudoprotease leads, in both stresses, to lower concentrations of hydrogen peroxide. However, the decrease of chloroplast copper/zinc superoxide dismutase 2 level was observed only during the high light stress. In both analyzed stressful conditions, proteins related to RubisCO folding, glycine metabolism, and photosystem I were identified as differently accumulating in egy3 mutant lines and WT plants; however, the functional status of PSII during analyzed stressful conditions remains very similar. Our results lead to a conclusion that EGY3 pseudoprotease participates in response to high light and high-temperature stress; however, its role is associated rather with photosystem I and light-independent reactions of photosynthesis.

Whitening efficacy of low concentration hydrogen peroxide photoactivated with blue or violet LED

BackgroundBleaching protocols using low concentration hydrogen peroxide (HP) photoactivated with LED sources have been widely discussed. Herein, we evaluated the whitening efficacy of 15% HP photoactivated with blue or violet LED compared to 35% HP. MethodsThirty bovine crowns were sectioned into 5 × 5 × 2 mm specimens. After staining in black tea, the specimens were randomized into three groups (n = 10): 35% HP, 15% HP + blue LED and 15% HP + violet LED. Two bleaching sessions were performed and the color assessment (∆L*, ∆a*, ∆b*, ∆Eab [CIELab], ∆E00 [CIEDE2000] and WID) was performed before, 24h after each session, 7 days and 1 month after the last session. Data were evaluated by two-way repeated measures ANOVA and Bonferroni post-test at a significance level of 5%. ResultsAll groups showed effective and similar results over 1 month of follow-up (p > 0.05), with only intragroup differences among the time intervals (p < 0.05). ConclusionsThe use of 15% HP photoactivated with blue or violet LED showed similar whitening efficacy compared to 35% HP. Thus, the association of low concentration bleaching gels with blue or violet LED sources can provide successful and less-aggressive treatment in terms of color change.

Enhanced photocatalytic degradation of methylene blue by nanocomposites prepared by laser ablation of Bi on CNT-α-Fe2O3 nanoparticles

The low conductivity and high combination rate of photogenerated electrons (e-) and photogenerated holes (h+) are the real challenges of photocatalysis. These problems could be mitigated by the synthesis of heterostructured nanocomposites (NCs). In this study, Bi@CNT-Fe2O3 nanocomposite was fabricated via pulsed laser ablation in liquid and characterized by UV–Vis spectroscopy, photoluminescence (PL), X-ray diffraction (PXRD) and field scanning electron microscopy (FESEM). These techniques revealed successfully the formation of CNT-α-Fe2O3 and Bi@CNT-α-Fe2O3 nanocomposites. The photocatalytic activities of the Fe2O3, CNT-α-Fe2O3, and Bi@CNT-Fe2O3 photocatalysts were evaluated by the degradation of methylene blue (MB) dye under ultraviolet (UV) light irradiation in the presence of a very low concentration of hydrogen peroxide (H2O2) as an oxidizing agent. The results show that the Bi@CNT-α-Fe2O3 NC has the highest photocatalytic degradation efficiency of MB which completes in 20 min of UV light irradiation. In addition, the obtained rate constants (min−1) of Bi@CNT-α-Fe2O3 NC were 1.3 and 3.4 times higher than those of CNT-α-Fe2O3 and α-Fe2O3. nanocatalysts, respectively.

Photocatalytic degradation of acetamiprid in a rotating photoreactor - Determination of reactive species

In this work, the photocatalytic degradation of acetamiprid under UV-A light was studied in a rotating photoreactor operating in recirculated batch mode and using an immobilized layer of a modified TiO2 photocatalyst. The aim of the study was to determine the reactive oxygen radicals and to investigate the influence of interfering compounds, which are crucial for the successful photocatalytic degradation of acetamiprid.Superoxide anion radicals and singlet oxygen play a crucial role in the photocatalytic degradation mechanism of acetamiprid. In the presence of low concentrations of hydrogen peroxide, the degradation of acetamiprid is significantly enhanced.

Effects of spermidine on germination of Salix spp. after storage under controlled conditions

Willows produce fast germinating and short-lived seeds, difficult to store in the long-term under controlled conditions. The aim of this study was to examine the feasibility of storage of three Salix spp. at controlled temperatures (3°, −10°, −196 °C). We also analyzed the effect of spermidine (Spd) as an antioxidant factor in desiccated seeds. Collected seeds were either desiccated or hydrated to obtain 10 levels of moisture content (between app. 4% and 2%) and subjected to storage at temperatures 3°, −10°, or −196 °C (liquid nitrogen; LN). After two months, seeds were germinated on the light at 20 °C. Seeds desiccated below a safe range of moisture content were further tested and germinated on filter paper with additions of 0.25 mM Spd solution. After 7 days seedlings were examined for hydrogen peroxide content (H2O2) and total antioxidant capacity (TAC). Fresh seeds of three Salix species: Persian willow (S. aegyptiaca L.), heartleaf willow (S. cordata Michx.) and crack willow (S. ×fragilis L.) were successfully stored at temperature −10° and −196 °C for two months. After cryopreservation seed of S. aegyptiaca, S. cordata, and S. ×fragilis germinated without viability loss in moisture content ranging from 4.4–15.9%, 6.4–18.5%, and 7.1–11.5% respectively. The addition of Spd during germination of desiccated seed did not affect germination capacity. However, seedlings of S. aegyptiaca had lower hydrogen peroxide content in comparison with control (germination on water). Seedlings of S. cordata showed an increase in hydrogen peroxide content in control after storing in LN. In seedlings of Crack willow Spd increased hydrogen peroxide content. Seeds of tested species differ in response to storage conditions. Salix seeds can be stored successfully for two months at −10° or −196 °C without losing viability in the safe range of moisture content. Storing at 3 °C can be used for storage in the narrower range of seeds’ moisture content, however, seedlings stored at this temperature produce a higher level of reactive oxygen species. Germinating seeds in Spd did not increase their germination, however in S. aegyptiaca and S. cordata decreased hydrogen peroxide content

PERÓXIDO DE HIDROGÊNIO COMO ATENUANTE DO ESTRESSE SALINO EM MARACUJAZEIRO-AZEDO

ABSTRACT Sour passion fruit is a fruit crop widely cultivated throughout Brazil, due to its adaptation to the tropical climate. However, in semi-arid regions its development is limited by the high concentration of soluble salts in the waters commonly used in irrigation. In this context, exogenous application of low concentrations of hydrogen peroxide can attenuate the damage caused by salt stress. The objective of this study was to evaluate electrolyte leakage, photosynthetic pigments and photochemical efficiency in sour passion fruit cv. BRS Rubi do Cerrado under irrigation with saline waters and foliar application of hydrogen peroxide. A completely randomized design was used, with treatments arranged in split plots, corresponding to five levels of irrigation water salinity - ECw (0.6; 1.2; 1.8; 2.4 and 3.0 dS m−1) and four concentrations of hydrogen peroxide - H2O2 (0; 15; 30 and 45 μM of H2O2) in plots and subplots, respectively. Irrigation with saline water reduced chlorophyll a and total chlorophyll contents of sour passion fruit plants cv. BRS Rubi do Cerrado, at 240 days after transplanting. Hydrogen peroxide at concentration of 15 μM stimulated chlorophyll a and total chlorophyll biosynthesis and, at 45 μM, relieved the effect of 3.0 dS m−1 water salinity on electrolyte leakage in the leaf blade of sour passion fruit. Salt stress did not affect the initial, maximum, variable fluorescence and quantum efficiency of photosystem II of sour passion fruit cv. BRS Rubi do Cerrado.

Chitosan oxidative scission in self‐neutralizing biocompatible solution of peroxycarbonic acid under high‐pressure CO2

AbstractAn important scientific task is the search for inexpensive and environmentally friendly methods for the production of chitosan oligomers. In the present work, the possibility of chitosan decomposition in the presence of peroxycarbonic acid solutions under high CO2 pressure was investigated. This medium contains self‐neutralizing carbonic acid used here to dissolve chitosan as well as peroxycarbonic acid formed from aqueous hydrogen peroxide, which acts as an oxidizing agent strong enough to break the glycosidic bonds of chitosan. The resulting chitosan decomposition product was analyzed by a number of analytical methods, such as IR spectroscopy, UV–vis spectroscopy, X‐ray photoelectron spectroscopy, high resolution mass spectrometry, and X‐ray diffraction. It was found that even with relatively low concentrations of hydrogen peroxide and short processing times, it is possible to obtain chitosan oligomers with a molecular weight of about 14 kDa. The obtained polymer was examined by SEM and TG. It showed a good ability to form porous matrices, while its thermal stability somewhat decreased.

Leaching of Electric Arc Furnace Slag for Selective Recovery of Iron: Effect of Temperature, H2SO4/HCl Acid, and Oxidant Concentration

A significant amount of electric arc furnace slag (EAFS) is generated as a by-product from the steelmaking industry. Acid leaching was carried out with both the presence and absence of oxidants to intensify the iron recovery from EAFS in the final product. Oxidative leaching refers to the process whereby the oxidant helps in removing one or more electrons in a chemical reaction. In contrast, non-oxidative leaching means there is no transfer of electrons during the process. In this study, hydrogen peroxide and potassium permanganate were used as the oxidants in the leaching process. The influences of the leaching factors, such as the concentration of leaching reagent (0.5–8 M), leaching temperature (323–363 K), EAFS particle size (50–300 μm) and concentration of the oxidants (0.5–2 M), were also studied. The findings revealed that the particle size, acid dosage and type of oxidants significantly influenced iron recovery. Smaller particle sizes greatly improved the recovery of iron. İn the non-oxidative leaching environment, sulphuric acid exhibited a higher iron recovery than hydrochloric acid. The recovery efficiency was 21.47% higher. For oxidative leaching, the leaching efficiency of iron was more favourable at lower concentrations of hydrogen peroxide in both sulphuric and hydrochloric acid, and the opposite was the case for potassium permanganate. An overdose of hydrogen peroxide can cause radical quenching, which will reduce oxidant utilisation. Oxidative leaching resulted in better iron recovery at optimum leaching conditions with a temperature of 50°C, 5 M H2SO4, 1 M hydrogen peroxide, a leaching time of 60 minutes, a solid to liquid ratio of 1:20 and a stirring rate of 300 rpm.

Postharvest quality comparison of six blackberry cultivars under two storage conditions

The fruit of six blackberry cultivars “Ningzhi 3,” “Arapaho,” “Kiowa,” “Hull,” “Shuofeng,” and “Triple Crown” were stored under different storage conditions 25°C (RT) and 4°C (LT). Compared to RT treatment, LT treatment-restricted deterioration and nutritional loss, and maintained antioxidant capacity of samples. Among LT samples, color of “Ningzhi 3,” “Hull,” and “Shuofeng” changed fewer than other cultivars, and the decay rate of “Shuofeng” and weight loss of “Hull” were lower than others. At the end of LT, total soluble solid and soluble sugar content of “Arapaho,” soluble protein content of “Shuofeng” were the highest. During the storage period, “Arapaho,” “Hull”, and “Shuofeng” maintained higher antioxidant enzyme activity and lower hydrogen peroxide content. The storage stability of “Arapaho,” “Hull,” and “Shuofeng” was better than the other three blackberry cultivars because of their better postharvest quality. This study provides a comprehensive insight into the postharvest treatment to maintain the quality of blackberry.

Effect of various factors on ejaculate fertility in vitro

Introduction. Current demographic situation in Russia is characterized by decreasing birth rate. According to the World Health Organization, percentage of child-free marriages in various countries is 10–15 %. In Russia, the National Medical Research Center for Obstetrics, Gynecology, and Perinatology named after Academician V.I. Kulakov states that this number is 17 %. More than 4 million men suffer from infertility of various types. In recent years, pathologies of male reproductive function have achieved medical and social significance due to progressively decreasing sperm fertility. Fertility disorders are considered multi-factor conditions caused by internal and external factors and leading to pathological changes in sex organs. Correction of pathologies of male fertility does not always lead to positive results. Therefore, it is important to develop and study effective pharmaceuticals affecting the main fertility parameters.The study objective is to investigate the effect of various biological pharmaceuticals, physical and chemical factors on parameters of ejaculate fertility in vitro.Materials and methods. Experiments with a protein-peptide complex (PPC), methylene blue, and hydrogen peroxide were performed on human semen. After semen dilution, the sample was studied under the microscope and sperm motility and other ejaculate parameters were evaluated per the 5th edition WHO standard. Experiments were performed at 20–22 ºС. Statistical data analysis was performed using the Student’s t-test. Differences were considered statistically significant at р &lt;0.05.Results. The results show increased motility in the fraction of active motile sperm in first 30 minutes after incubation with methylene blue. In case of initial asthenospermia, active motility increased by 72 %, in case of normospermia by 89 %. After 2 hours, all motility fractions were at the baseline level.The experiments also showed significant changes in sperm motility in the presence of PPC preparation in the ejaculate: increase in sperm motility was observed beginning at 30-minute mark and this level persisted through 3 hours of observation. A more pronounced change, by 60 %, was observed in the active motile sperm; total motility increased by up to 30 %. After 24 hours, sperm motility remained close to the baseline level, the number of normal sperm forms and live cells did not change. Dependence of the motility change on the preparation concentration should be noted: the highest increase was observed at PPC concentration with total protein level of 10–12 mg/mL. Higher concentrations did not have a positive effect on sperm motility. In experiments with low hydrogen peroxide concentration, a positive effect on sperm motility was observed.Conclusions. Sperm motility is supported by glycolysis energy, and one of the glycolysis enzymes glyceraldehyde 3-phosphate dehydrogenase is tightly bound to the fibrous layer of the flagellum, activation of metabolic pathways leading to increased enzyme activity, increased sperm motility. The mechanism of the observed effect is not entirely clear, however, the obtained data demonstrate potential benefits of further studies on use of pharmaceuticals in andrological and reproductive practice, assisted reproductive technologies, as well as for stimulation of sperm motility in further experimental studies.

Arbuscular Mycorrhizal Fungi and Endophytic Fungi Activate Leaf Antioxidant Defense System of Lane Late Navel Orange.

Arbuscular mycorrhizal (AM) fungi and endophytic fungi collectively symbiose well with plants and, thus, stimulate plant growth; however, it is not clear whether field inoculation of the fungi enhances the resistance potential of plants, particularly in citrus. In the present study, we inoculated AM fungi (Acaulospora scrobiculata, Diversispora spurca, and D. versiformis) and endophytic fungi (Piriformospora indica) on an eight-year-old lane late navel orange (Citrus sinensis (L.) Osb) trees grafted on Poncirus trifoliata in a field, and we analyzed the response of the leaf antioxidant defense system. Approximately 2 years after inoculation, the root fungal colonization rate and soil hyphal length significantly increased. Fungal inoculation significantly increased the activity of leaf antioxidant enzymes, such as superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, and the content of non-enzymatic antioxidants, such as reduced ascorbic acid and reduced glutathione. As a result, fungi-inoculated plants maintained lower concentrations of hydrogen peroxide and superoxide anion radicals and lower levels of membrane lipid peroxidation (according to malondialdehyde level) in leaves than uninoculated plants. Among them, inoculation of D. spurca and A. scrobiculata showed relatively higher effects in enhancing the antioxidant defense system than the other fungi. Furthermore, inoculation of D. spurca induced expressions of CsFe-SOD, CsMn-SOD, CsPOD, CsCAT1, and CsPRR7; inoculation of A. scrobiculata and D. versiformis induced expressions of CsCAT1; CsCAT1 and CsPOD were also induced by inoculation of P. indica. All four inoculations almost upregulated expressions of CsFAD6. AM fungi had superior effects than endophytic fungi (e.g., P. indica). According to our findings, inoculation with beneficial fungi, specifically mycorrhizal fungus D. spurca, activated the antioxidant defense system of field citrus trees, thus, having potentially superior resistance in inoculated plants.