Low Molecular Weight Antioxidants Research Articles

Investigation of biological-rhythm patterns: physiological and biochemical effects in herbaceous plants exposed to low-level chronic radiation – part 1: nonirradiated seeds

Hypothesis Because reactive oxygen species are involved in the regulation of biological rhythms, we hypothesized that intra-annual variability of seed progeny quality at low doses of ionizing radiation (LDIRs) would differ from that of background plants. Materials and methods We conducted 12 consecutive experiments using the roll culture method by germinating seeds (monthly for 3 weeks) of six herbaceous plant species (Bromus inermis, Geum aleppicum, Plantago major, Rumex confertus, Silene latifolia, and Taraxacum officinale) growing under conditions of chronic radiation in the East Ural Radioactive Trace (EURT). We assessed physiological (seed viability and abnormality frequency) and biochemical (low-molecular-weight antioxidants, LMWAs) parameters of seedlings. Results Total absorbed dose rates of maternal plants (TADRplants) and seed embryos (TADRseeds) in the EURT exceeded background levels by 1–3 and 1–2 orders of magnitude, respectively. Nonlinear dependencies on TADR were mainly characteristic of physiological and biochemical parameters. For most populations of the studied species (B. inermis, G. aleppicum, R. confertus, and S. latifolia), seedling survival and root length decreased in the autumn–winter period, while the frequency of abnormal seedlings increased. The content of LMWAs could be ranked as R. confertus > B. inermis > G. aleppicum > S. latifolia, in good agreement with the presence of anthocyanin pigmentation in the plants. The lowest synthesis of antioxidants in seedlings was observed in winter. A high LMWA content promoted growth and reduced the frequency of abnormal seedlings. Conclusions These results underscore a multistage nature of the impact of LDIRs on intra-annual biological rhythms in plants. High heterogeneity in reference group ‘wild grasses’ and diversity of their radiobiological effects should help to develop methods of radiation protection for natural ecosystems and facilitate approaches used by the International Commission on Radiological Protection. Highlights Absorbed dose rates for six plant species in the East Ural Radioactive Trace (EURT) area range from 0.11 to 73.89 µGy h−s (plants) and 0.11 to 6.88 µGy h−s (seed embryos). Intra-annual rhythms of physiological and biochemical parameters in the EURT zone differ from those in background seedlings. Plants in the EURT area exhibit a wide range of trait variability, asynchrony of the manifestation of the effects, nonlinear dose–response relations, and hormesis. A high content of low-molecular-weight antioxidants (LMWAs) is associated with low frequency of developmental abnormalities and high viability of seed progeny.

Increase in ascorbate content in leaves of Hordeum vulgare after spraying with cold atmospheric plasma-treated water in combination with waterlogging and re-aeration

Flood events are likely to increase in the near future and are one of the events most threatening to agricultural production. Barley is the fourth most important crop and the cereal most sensitive to excessive moisture stress. Improving the stress tolerance of crops to a variety of stress factors caused by a more volatile climate is an important task for the coming years. The aim of this study was to investigate the efficacy of cold atmospheric plasma-treated water (PTW) as a foliar spray to stimulate the antioxidant system of Hordeum vulgare and thereby improve plant stress tolerance. For this purpose, we analysed the components of the ascorbate-glutathione cycle in barley leaves and roots without stress and under waterlogging conditions. PTW increased the content of total and reduced ascorbate in leaves as well as the content of reduced ascorbate in roots four weeks after treatment. This was observed both, under stress free conditions and after waterlogging and re-aeration. In leaves, enzyme activities also increased after re-aeration, and in roots, total and reduced glutathione levels increased after waterlogging compared to the control. The accumulation of low molecular weight antioxidants may increase tolerance to a variety of stress factors through more efficient scavenging of ROS. Overall, treatment of plants with PTW may trigger an adaptive response that leads to mitigation of the negative effects of stress, and thus, could be used as a priming agent for protection against subsequent more severe stress factors that occur in the plants' natural environment.

Epigenetic factors of the effect of UV-C and X-ray presowing seeds radiation exposure in Matricaria chamomilla L. genotypes

In a series of experiments using both X-ray and UV-C radiation exposure a parallel study of several pharmacological characteristics of the Matricaria chamomilla L. genotype group was carried out. The data concerning the changes in the productivity of pharmacological raw materials and stimulation of the synthesis of low molecular weight antioxidants as markers of secondary metabolism induction have been published earlier. In this study, the data on the relationship between the stimulation of the synthesis of secondary metabolites under different types of irradiation and the epigenetic changes in the plant organism are presented. It was shown that DNA methylation was switched to the de novo mode in plants of all studied genotypes of M. chamomilla under both types of irradiation. That indicates changes in the epigenetic program of the plant organism. Comparison of the epigenetic pattern between control and irradiated samples, based on the difference in DNA methylation patterns in terms of a statistical indicator, shows that there is no unambiguous relationship between the epigenetic changes and increasing yield of antioxidant synthesis. This is additional evidence of the diversity of metabolic rearrangements and adaptive strategies of the plant organism under radiation exposure even within one species.

The influence of newly synthesized tellurium-containing cyanine dyes on the intensity of oxidative processes in the bodies of mammals

The purpose of this work was to study the influence of new synthesized organotellurium compounds (TOCs) on the intensity of oxidative processes in the body of mammals – in this case, the blood and liver of rats.The experiments were performed on white outbred rats, which were given a single dose of various TOC derivatives (0.01 g/kg). The next day, the animals were decapitated, blood was collected and the liver was isolated. The content of products of oxidative modification of lipids and proteins, as well as the low molecular weight antioxidant glutathione, was determined in blood plasma, erythrocytes and liver homogenate.It was found that all TOC derivatives studied significantly increase the intensity of lipid peroxidation in erythrocytes and hepatocytes, as evidenced by a multiple increase in the concentration of malondialdehyde (MDA) in them. At the same time, TOC suppresses the levels of oxidative damage to liver proteins, which is expressed in a significant decrease in the content of carbonyl groups. A study of glutathione content in the rat erythrocytes showed the absence of any significant effects of TOS on this antioxidant in erythrocytes.However, changes in its concentration were found in the liver, which depend on the nature of TOS (for TOS1 and TOS3 a decrease and for TOS2 a slight increase). Newly synthesized TOC demonstrate pronounced prooxidant properties, significantly increasing the intensity of oxidative processes in lipids, which makes them promising agents for antibacterial, antiviral and antitumor therapy.

Respiratory tract lining fluid copper content contributes to pulmonary oxidative stress in patients with systemic sclerosis

Background Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of the skin and internal organs, mostly affecting young and middle-aged women. Significant questions remain as to its pathogenesis, especially the triggers for the associated interstitial lung disease (SSc-ILD). We examined the extent to which SSc and SSc-ILD were related to oxidative stress and altered metal homeostasis at the air-lung interface. Methods In this case-control study, we recruited 20 SSc patients, of which 11 had SSc-ILD. Eighteen healthy individuals were recruited as age-matched healthy controls, for a total of 38 study participants. Low molecular weight antioxidants (ascorbate, urate and glutathione), metal transport and chelation proteins (transferrin and ferritin) and metals (Fe and Cu) concentrations, including a measure of the catalytically active metal pool, were determined in respiratory tract lining fluid (RTLF) collected by bronchoalveolar lavage from the SSc group and compared with healthy controls. Results In the SSc group, 14 individuals were of female sex (70%) and the median age was 57 years (range 35-75). We observed evidence of oxidative stress in the RTLFs of SSc patients, characterised by increased concentrations of glutathione disulphide (GSSG, P<0.01), dehydroascorbate (DHA, P<0.05) and urate (P<0.01). This was associated with elevated RTLF Fe (P=0.07) and Cu (P<0.001), and evidence of a catalytic metal pool, demonstrated by an enhanced rate of ascorbate oxidation in the recovered lavage fluid (p<0.01). Cu concentrations were significantly associated with the ascorbate depletion rate (r=0.76, P<0.001), and GSSG (r=0.38, P<0.05) and protein carbonyl (r=0.44, P<0.01) concentrations. Whilst these markers were all increased in SSc patients, we found no evidence for an association with SSc-ILD. Conclusions These data confirm the presence of oxidative stress in the airways of SSc patients and, for the first time, suggest that an underlying defect in metal homeostasis at the air-lung interface may play a role in disease progression.

The Mercury and Low Molecular-Weight Antioxidants Levels in Ungulates of the Republic of Karelia

The Mercury and Low Molecular-Weight Antioxidants Levels in Ungulates of the Republic of Karelia

Peculiarities of the effect of zinc chelate on prooxidant-antioxidant homeosta-sis in the blood of sows and their relationship with the reproductive capacity

During the last decades, research has been actively conducted to increase the reproductive capacity of sows. It was determined that during puberty, the sow’s body actively assimilates nutrients that should provide for their own needs and embryos and creates a reserve for the lactation period. The study aimed to determine the influence of zinc in the form of chelate on the state of prooxidant-antioxidant homeostasis on the reproductive capacity of sows. In the experiment, 45 heads of the Large White breed sows were used, and they were selected and divided into groups (5 heads each) according to the principle of analogs. The norms fed barren and farrowing sows according to their physiological state. The diet of the control group of sows from sexual rest to the 28th day of farrowing remained unchanged; the 1st experimental group – MD+5 % Zinc in the form of zinc chelate, the II experimental group – MD+10 % Zinc in the form of Zinc chelate. Additional feeding of biologically active compounds was stopped one day before farrowing. During the phase of sexual rest, estrus, on the 90th and 104th days of farrowing, the day of farrowing, as well as on the 5th and 28th days of the suckling period, blood was taken from sows and their piglets to determine the state of PAH. It has been determined that in the blood of sows, the periods of the reproductive cycle determine the peculiarities of the formation of prooxidant-antioxidant homeostasis. In particular, during estrus, there is an intensification of peroxide oxidation processes – the content of diene conjugates increases by 56.9 %, TBC-active compounds by 12.3 %, and the level of low molecular weight antioxidants – reduced glutathione decreases (Р < 0.001). This is accompanied by a significant increase in the activities of antioxidant enzymes – superoxide dismutase (Р < 0.05) and catalase (Р < 0.05). It was found that the intensification of peroxide oxidation processes is intensified on the day of farrowing of sows – the content of diene conjugates increases by 26.6 % and TBC-active compounds by 31.8 % with a further decrease during lactation to the level of sexual rest. Animals that received zinc in the form of zinc chelate 5 % above the norm were characterized by a lower intensity of peroxide oxidation processes. Additional feeding of zinc in the form of zinc chelate to sows by 10 % more than the norm is accompanied by a decrease in fertility (Р < 0.05), the number of live piglets (Р < 0.05), litter weight at birth by 10.0 % and litter weight at weaning – 11.6 %. Sows that received this feed supplement of microelement 5 % above the norm are characterized by higher fertility by 4 % and litter weight at birth by 4.2 %.

Antioxidative Strategy in Traumatic Brain Injury: Role of Low-Molecular-Weight Antioxidants

Objective: Traumatic brain injury (TBI) is a major cause of mortality and disability worldwide. This study was designed to investigate the beneficial and neuroprotective role of some Low-Molecular-Weight antioxidants (LMWA) in the treatment of TBI in albino rats.
 Methods: TBI was induced in adult albino rats using the weight-drop method. A total of 70 Rats was used and were divided into 12 treatment groups, a traumatized non-treated group (TNT) and a Non-traumatized non-treated group (NTNT). There were 5 rats per group. Each of the treatment groups received 22.5 or 45 mg/kg of dimethyl sulfoxide (DMSO), Alpha Lipoic acid (ALA), Uric acid (UA), vitamin C (VC), vitamin E (VE), or Mannitol. Treatment was started 30 min after the trauma and continued for 21 days. To evaluate the functional outcomes, the modified neurological severity score (mNSS) was calculated. The antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)], and malondialdehyde (MDA) were assayed to evaluate oxidative stress (OS). 
 Results: At 7 days post-TBI, the antioxidant-treated groups exhibited significant (p

Synthesis of macromolecular antioxidants containing thioether and aromatic secondary amine to improve the anti-oxidation properties of EPDM

A macromolecular antioxidant PM containing thioether and aromatic secondary amine was synthesized by the thiol-ene click reaction between the antioxidant N-(4-aminophenyl)maleimide (MC) and pentaerythritol tetra(3-mercapto propionate) (PETPM). Then, the curing properties and anti-oxidation properties of PM in EPDM were investigated. The results showed that PM reduced the negative effect of the coexisted of PETPM and MC (PETPM+MC) on rubber curing and improved the crosslinking density of the rubber. PM also exhibited high anti-volatility and anti-migration properties due to its high molecular mass. Moreover, the aromatic secondary amine group in PM was able to capture aging radicals and inhibit the occurrence of oxidation reactions, while the thioether group effectively decomposed hydroperoxides and inhibited the occurrence of autocatalytic oxidation reactions. The combination of these two groups improved the anti-oxidation properties of EPDM. As a result, PM/EPDM demonstrated the lowest crosslinking density change rate and carbonyl index, as well as the largest aging coefficient K when compared to the EPDM containing low molecular weight antioxidants (PETPM/EPDM, MC/EPDM, MC+PETPM/EPDM).

The Adaptive Role of Carotenoids and Anthocyanins in Solanum lycopersicum Pigment Mutants under High Irradiance.

The effects of high-intensity light on the pigment content, photosynthetic rate, and fluorescence parameters of photosystem II in high-pigment tomato mutants (hp 3005) and low-pigment mutants (lp 3617) were investigated. This study also evaluated the dry weight percentage of low molecular weight antioxidant capacity, expression patterns of some photoreceptor-regulated genes, and structural aspects of leaf mesophyll cells. The 3005 mutant displayed increased levels of photosynthetic pigments and anthocyanins, whereas the 3617 mutant demonstrated a heightened content of ultraviolet-absorbing pigments. The photosynthetic rate, photosystem II activity, antioxidant capacity, and carotenoid content were most pronounced in the high-pigment mutant after 72 h exposure to intense light. This mutant also exhibited an increase in leaf thickness and water content when exposed to high-intensity light, suggesting superior physiological adaptability and reduced photoinhibition. Our findings indicate that the enhanced adaptability of the high-pigment mutant might be attributed to increased flavonoid and carotenoid contents, leading to augmented expression of key genes associated with pigment synthesis and light regulation.

Structural features and antioxidant behavior of lignin polymers isolated from various woody plants

This article presents results of our study of the structural organization of macromolecules of natural lignins isolated from some coniferous and deciduous plants. The main feature of lignin as a polymer is the polyvariability at all levels of structural organization. The study showed that the studied samples were very individual and differed in the content of functional groups, elemental composition, and structural units of the guaiacyl, syringyl, and p-hydroxyphenyl types. Acacia lignin has the most interesting chemical structure, since p-hydroxyphenyl structures are absent in the macromolecule of this biopolymer. The molecular properties of the acacia and spruce lignins are investigated by the methods of high-speed sedimentation, translational diffusion and viscosimetry. It were determined the molecular weight of fractions, the scaling coefficients of the Mark-Kuhn-Houwink equation, fractal dimension df and the value of the Tsvetkov-Klenin hydrodynamic invariant. Based on the analysis of the hydrodynamic behavior and topological structure of macromolecules, it was concluded that acacia lignin was a star-shaped polymer, and spruce lignin was a randomly branched polymer. The studied lignins have interesting and promising biomedical properties. The main feature of lignins is their high antioxidant activity (AOA), which is comparable with the activity of well-known low molecular weight antioxidants. It was shown that lignins from acacia and walnut wood were characterized by the highest AOA. In addition, lignins have excellent sorption properties against the extremely toxic aflatoxin B1 produced by the so-called "yellow mold"(fungi of the genus Aspergillus flavus). The lignin from walnut wood with the index of irreversible adsorption of AF reaching 68.4% should be considered the most effective.

Impact of varying light spectral compositions on photosynthesis, morphology, chloroplast ultrastructure, and expression of light-responsive genes in Marchantia polymorpha

Marchantia polymorpha is a convenient model for studying light of different spectral compositions on various physiological and biochemical processes because its photoreceptor system is vastly simplified. The influence of red light (RL, 660 nm), far-red light (FRL, 730 nm), blue light (BL, 450 nm), and green light (GL, 525 nm) compared to white light (high-pressure sodium light (HPSL), white LEDs (WL 450 + 580 nm) and white fluorescent light (WFL) on photosynthetic and transpiration rates, photosystem II (PSII) activity, photomorphogenesis, and the expression of light and hormonal signaling genes was studied. The ultrastructure of the chloroplasts in different tissues of the gametophyte M. polymorpha was examined. FRL led to the formation of agranal chloroplasts (in the epidermis and the chlorenchyma) with a high starch content (in the parenchyma), which led to a reduced intensity of photosynthesis. BL increased the transcription of genes for the biosynthesis of secondary metabolites - chalcone synthase (CHS), cellulose synthase (CELL), and L-ascorbate peroxidase (APOX3), which is consistent with the increased activity of low-molecular weight antioxidants. FRL increased the expression of phytochrome apoprotein (PHY) and cytokinin oxidase (CYTox) genes, but the expression of the phytochrome interacting factor (PIF) gene decreased, which was accompanied by a significant change in gametophyte morphology. Analysis of crosstalk gene expression, and changes in morphology and photosynthetic activity was carried out.

Oxidative Stress in Healthy and Pathological Red Blood Cells.

Red cell diseases encompass a group of inherited or acquired erythrocyte disorders that affect the structure, function, or production of red blood cells (RBCs). These disorders can lead to various clinical manifestations, including anemia, hemolysis, inflammation, and impaired oxygen-carrying capacity. Oxidative stress, characterized by an imbalance between the production of reactive oxygen species (ROS) and the antioxidant defense mechanisms, plays a significant role in the pathophysiology of red cell diseases. In this review, we discuss the most relevant oxidant species involved in RBC damage, the enzymatic and low molecular weight antioxidant systems that protect RBCs against oxidative injury, and finally, the role of oxidative stress in different red cell diseases, including sickle cell disease, glucose 6-phosphate dehydrogenase deficiency, and pyruvate kinase deficiency, highlighting the underlying mechanisms leading to pathological RBC phenotypes.

Effect of the biofertilizer on biomass and content of low molecular weight antioxidants in Brassica oleracea within copper biofortification

Effect of the biofertilizer on biomass and content of low molecular weight antioxidants in Brassica oleracea within copper biofortification

Acetylsalicylic acid as the only pharmacological method for the prevention of preeclampsia: A retrospective study

Background. Preeclampsia (PE) complicates 28% of pregnancies worldwide, negatively impacting the pregnant woman and the fetus. Therefore, its prevention remains relevant. It is believed that the cause of PE, especially early PE, is a placentation disorder. It warrants studying drugs that can improve placenta development. The leadership in this matter is maintained by acetylsalicylic acid, which, according to the ASPRE study, reduced the incidence of PE at 34 weeks of pregnancy by 82%. The use of low molecular weight heparins (LMWH), dipyridamole, and antioxidants for PE prevention remains controversial and continues to be studied by foreign and Russian scientists.
 Aim. To assess the efficacy of acetylsalicylic acid, LMWH, dipyridamole (Curantyl), and bovine blood derivates (Actovegin) in the Russian population of pregnant women at high risk for PE prevention.
 Materials and methods. The study included 244 patients. We reviewed the archived case records of 103 patients diagnosed with severe PE, who delivered in 2019 at the State Clinical Hospital №24, and 141 pregnant women from the Maternity clinic №3 at the Veresaev Moscow State Clinical Hospital, where the risk of PE was assessed as high, according to the results of extended combined screening of the first trimester of pregnancy. Eighty-nine pregnant women received acetylsalicylic acid at a dose of 75 mg and 54 at a dose of 150 mg. In addition, 22 patients received LMWH, 6 dipyridamole, and 3 Actovegin. The absolute risks, the risk ratio, and statistical significance when taking drugs in each risk group were calculated to assess the efficacy of acetylsalicylic acid and other drugs for PE prevention in the above risk groups.
 Results. The resulting weak inverse correlation (r=-0.31) between the PE severity at delivery and the dose of acetylsalicylic acid indicates that an increase in the acetylsalicylic acid dose was associated with a decrease in the PE severity. The effectiveness of combinations of various drugs for PE prevention was assessed by analyzing factor correspondences. Two-dimensional scaling of the most likely combinations showed that most patients received acetylsalicylic acid in the high-risk group with no PE. Additional use of LMWH, Curantyl, and Actovegin did not reduce the risk of PE.
 Conclusion. Acetylsalicylic acid is the only pharmaceutical method for preventing PE in high-risk groups. Higher doses of acetylsalicylic acid are associated with lower PE severity.

Survival rates and pro-oxidant-antioxidant systems of germinated Yakutian plant seeds pretreated with super-weak constant magnetic fields of different flux densities

The aim of this study was to identify physiological and biochemical changes in seedlings of wild plants of Yakutia, grown from seeds, which have received a pre-sowing, super-weak constant magnetic field treatment of different magnetic flux densities. Review of literature sources allows us to conclude that the weak effects of low-intensity fields (nonthermal character) have not been studied sufficiently so far. The study was conducted on seeds from 14 different species of wild plants native to Yakutia. The seeds were subjected to different magnetic flux strengths of 0.2–4.0 mT for 24 hours and then were germinated on filter paper. The criterion for evaluating the effect of the super-weak constant magnetic field was the formation of a true leaf in seedlings (survival rate). The intensity of lipid peroxidation processes was recorded as a pro-oxidant reaction. The total content of low molecular weight antioxidants was determined as an example of the non-enzymatic antioxidant system. The activity of an antioxidant enzyme, superoxide dismutase, was determined. The effects of the super-weak constant magnetic fields were evaluated using regression and statistical methods. Based on the working hypothesis is that the formation of the present leaf is dependent on changes in the pro-oxidant-antioxidant equilibrium in the cells of the seedlings as a result of the action on them by the super-weak constant magnetic field as a function of the magnetic flux density. We showed that the survival rate of seedlings grown from the seeds pre-treated by super-weak constant magnetic fields of different magnetic flux density for 24 hours leads to the activation of lipid peroxidation and depends on the adaptation processes of antioxidant systems (the sum of low-molecular antioxidants and superoxide dismutase activity): simple compensation or hypercompensation. In the second case, the action of super-weak constant magnetic fields leads to an increase in the survival rate of seedlings by the criterion of the formation of the true leaf. The study is of significance for specialists in magneto-biology and researchers of plant antioxidant systems.

Investigating the Physiological and Molecular Responses of Solanum lycopersicum hp Mutants to Light of Different Quality for Biotechnological Applications.

The effect of the light of different spectral compositions, white fluorescent light (WFL), red light (RL, 660 nm), blue light (BL, 450 nm), green light (GL, 525 nm), and white LED light (WL, 450 + 580 nm), on the physiological parameters of Solanum lycopersicum 3005 hp-2 (defective for a DET1 gene) and 4012 hp-1w; 3538 hp-1; 0279 hp-1.2 (defective for a DDB1a gene) photomorphogenetic mutants was studied. The parameters of the primary photochemical processes of photosynthesis, photosynthetic and transpiration rates, the antioxidant capacity of low-molecular weight antioxidants, the content of the total phenolic compounds, including flavonoids, and the expression of the genes involved in light signaling and biosynthesis of secondary metabolites were determined. Under BL, the 3005 hp-2 mutant showed the highest nonenzymatic antioxidant activity, which occurred to a greater extent due to the increase in flavonoid content. At the same time, under BL, the number of secretory trichomes on the surface of the leaves of all mutants increased equally. This suggests the accumulation of flavonoids inside leaf cells rather than in trichomes on the leaf surface. The data obtained indicate the possibility of using the hp-2 mutant for biotechnology to increase its nutritional value by enhancing the content of flavonoids and other antioxidants by modulating the spectral composition of light.

The Impact of Convection Drying Temperature on Content of Selected Phytochemicals in Dried Wild Garlic Leaves (Allium ursinum L.)

Abstract Wild garlic is a well-known and highly valued herbal plant. It is used fresh, unprocessed, and in the form of dried plants. The paper presents the results of the impact of the applied convection drying conditions at 30, 40 and 60°C on the parameters of the drying process as well as selected properties and composition of dried garlic obtained from wild garlic. It has been unequivocally shown that the increase in drying temperature significantly affects the content of thermally labile compounds, especially low-molecular weight antioxidants, including polyphenols and vitamin C. The analysis of the results clearly indicates that the dried plants obtained at 30°C contain relatively the highest amounts of antioxidant components and show the most volatile compounds profile similar to fresh wild garlic. However, the analysis of the parameters of drying process revealed that the temperature of the process significantly affects the time needed for the completion of drying process. The recommended of the most favourable process conditions should be based on an extended analysis and optimization of the entire process, taking into account not only the quality parameters of the dried material, but other parameters such as energy inputs and labour costs.

Design of a new self-assembling antioxidant nanomedicine to ameliorate oxidative stress in zebrafish embryos.

Oxidative stress, which is a persistent state of elevated reactive oxygen species (ROS), is implicated in the pathogeneses of several diseases, making antioxidant-based therapeutics the aptest intervention. Nevertheless, the clinical failure of conventional low-molecular-weight (LMW) antioxidants in oxidative stress-related diseases to yield favorable therapeutic outcomes and an increased mortality rate attributable to their poor pharmacokinetic characteristics, necessitates the development of alternative therapeutics. In light of this, we designed and synthesized a new amphiphilic polymer functionalized with a clinically safe base polymer of poly(styrene-co-maleic anhydride) copolymer conjugated with the LMW pleiotropic antioxidant TEMPO (a potent antioxidant) and biocompatible poly(ethylene glycol) (TEMPO-installed PSMA-g-PEG), which self-assembles into nano-sized micelles (SMAPoTN) under physiological conditions. We investigated its safety and antioxidant ability using zebrafish models. Common LMW antioxidants, such as 4-hydroxy-TEMPO (TEMPOL), vitamin C, N-acetyl-L-cysteine, and edaravone exposure induced phenotypic distortions, a manifestation of developmental toxicity, and resulted in high lethality in zebrafish larvae. LMW TEMPOL also adversely affected embryo hatchability, induced arrhythmia and cardiac edema, and failed to protect against oxidative stress. In contrast, exposure of zebrafish embryos to SMAPoTN increased the hatchability, protected embryos against various inducers of oxidative stress, and did not induce any phenotypic alterations or discernible toxicity. Taken together, we conclude that SMAPoTN surpasses LMW TEMPOL in terms of the ability to protect zebrafish, attributable to efficient ROS scavenging without perturbing normal redox homeostasis. These results imply that SMAPoTN can be used as a therapeutic intervention against various oxidative stress-induced diseases. STATEMENT OF SIGNIFICANCE: Failure of low molecular weight (LMW) antioxidants to improve therapeutic index in various oxidative stress-related pathogenesis, attributable to their poor pharmacokinetic characteristics, greatly limits their clinical translation. To overcome this limitation, we developed a self-assembling antioxidant nanoparticle (SMAPoTN) comprised of amphiphilic polymer; poly(styrene-co-maleic anhydride) conjugated with TEMPO as an antioxidant and biocompatible poly(ethylene glycol). Preliminary studies carried out in the in vivo models of zebrafish embryos confirmed that exposure of LMW antioxidant resulted in acute developmental toxicity, high lethality, and failure to rescue embryos against oxidative stress inducers. In contrast, SMAPoTN did not exert discernible toxicity and significantly improved their survival under oxidative stress. Our finding establishes antioxidant nanoparticles as more suitable therapeutic intervention for oxidative stress-induced diseases than LMW antioxidants.

The Effect of Short-Term Heating on Photosynthetic Activity, Pigment Content, and Pro-/Antioxidant Balance of A. thaliana Phytochrome Mutants.

The effects of heating (40 °C, 1 and 2 h) in dark and light conditions on the photosynthetic activity (photosynthesis rate and photosystem II activity), content of photosynthetic pigments, activity of antioxidant enzymes, content of thiobarbituric acid reactive substances (TBARs), and expression of a number of key genes of antioxidant enzymes and photosynthetic proteins were studied. It was shown that, in darkness, heating reduced CO2 gas exchange, photosystem II activity, and the content of photosynthetic pigments to a greater extent in the phyB mutant than in the wild type (WT). The content of TBARs increased only in the phyB mutant, which is apparently associated with a sharp increase in the total peroxidase activity in WT and its decrease in the phyB mutant, which is consistent with a noticeable decrease in photosynthetic activity and the content of photosynthetic pigments in the mutant. No differences were indicated in all heated samples under light. It is assumed that the resistance of the photosynthetic apparatus to a short-term elevated temperature depends on the content of PHYB active form and is probably determined by the effect of phytochrome on the content of low-molecular weight antioxidants and the activity of antioxidant enzymes.