Antioxidant defence mechanisms: from the beginning to the end (of the beginning)

Does persistent organic pollutant PFOS (perfluorooctane sulfonate) negative impacts on the aquatic invertebrate organism, Astacus leptodactylus [Eschscholtz, 1823]

Highly persistent perfluorooctane sulfonate (PFOS) is an industrial fluorinated organic chemical with significant bioaccumulation and biomagnification properties. The purpose of this study was to determine the toxic effects of sublethal PFOS on the aquatic invertebrate organism, narrow-clawed crayfish [Astacus leptodactylus Eschscholtz, 1823]. The 96 h LC₅₀ value was determined as 48.81 mg/L (34.19-63.68 mg/L) with probit analysis. The sublethal experimental design was formed into four groups solvent control (DMSO, dimethyl sulphoxide), non-treated control group, and 1/10 (5 mg/L) and 1/100 (0.5 mg/L) of 96 h LC₅₀ of PFOS, and crayfish were exposed for 48 h, 7 d, and 21 d under laboratory conditions. Total haemocyte counts (THCs) decreased, while the haemolymph total antioxidant status (TAS) values increased (p < 0.05) after exposure to 0.5 and 5 mg/L PFOS for 48 h, 7 d, and 21 d. Haemolymph total oxidative stress (TOS) levels significantly increased at 5 mg/L PFOS concentration (p < 0.05). Catalase (CAT) activities increased at both concentrations after 48 h and 7 d and then returned to control levels after 21 d; whereas superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities did not change in muscle tissue (p > 0.05). GPX and CAT activities decreased, but SOD activity increased in hepatopancreas tissue (p < 0.05). SOD activity at both concentrations and CAT activity at 5 mg/L PFOS exposure decreased in gill tissue, while GPX activity increased at both concentrations of 48 h and 7 d and returned to control values on day 21 of exposure. Histopathological alterations were detected in hepatopancreas and gill tissues. Lamellar deformations, epithelial hyperplasia, and haemocytic infiltrations were observed in the gill tissues, whereas tubular degeneration, tubule loss, necrosis, and lesions in the hepatopancreas tissues were the major recorded alterations. As a result, the sublethal concentrations of PFOS have toxic effects on crayfish and histologically cause tissue damage. Our findings also support a better understanding of the early toxicological effects of PFOS in freshwater ecosystems. Also, it could be concluded that A. leptodactylus is a reliable model for examining histopathological alterations and differences in enzyme activities together with the haemolymph findings in toxicology studies amid aquatic species.

MitoQ alleviates carbon tetrachloride-induced liver fibrosis in mice through regulating JNK/YAP pathway

Background

Liver fibrosis is a pathological wound-healing response caused by chronic liver damage. Mitochondria regulate hepatic energy metabolism and oxidative stress. Accumulating evidence has revealed that increased mitochondrial oxidative stress contributes to the activation of fibrogenesis. However, the roles and underlying mechanisms of mitochondrial oxidative stress in liver fibrosis remain unknown.

Methods and results

In this study, C57BL/6 mice were used to establish a model of liver fibrosis via oral gavage with CCl4 treatment for 8 weeks. Furthermore, intervention experiments were achieved by CCl4 combined with the intraperitoneal injection of mitoquinone mesylate (mitoQ). We demonstrated that the chronic CCl4 exposure resulted in severe hepatic fibrogenesis and significantly promoted the production of reactive oxygen species (ROS) and mitochondrial abnormalities. Besides, JNK/YAP pathway was also activated. By contrast, the administration of mitoQ markedly inhibited the expression of pro-fibrogenic transforming growth factor-β as well as type I collagen. The antifibrotic effects of mitoQ were also confirmed by hematoxylin and eosin staining and Sirius red staining. Moreover, mitoQ substantially reduced CCl4-induced mitochondrial damage and the release of ROS. Further studies suggested that this protection against liver fibrosis was mechanistically related to the inhibition of phosphorylation of JNK and the nuclear translocation of YAP.

Conclusion

In conclusion, these findings revealed that mitoQ attenuated liver fibrosis by inhibiting ROS production and the JNK/YAP signaling pathway. Selective targeting JNK/YAP may serve as a therapeutic strategy for retarding progression of chronic liver disease.

Effects of air exposure stress on crustaceans: Histopathological changes, antioxidant and immunity of the red swamp crayfish Procambarus clarkii

Air exposure stress may result in oxidative damage and ultimately disease or death in crustaceans. Using the Procambarus clarkia, one of the main commercial aquaculture species in China, as a study model, the molecular mechanism including histopathological changes, antioxidant capacity and immunity response under the air exposure stress were firstly evaluated. Results showed that the surfaces of gill were wrinkled while the morphologies of the nuclei and mitochondria in the hepatopancreas were altered after 48 h of air exposure stress, and the damage of mitochondria was more serious after additional bacterial infection. Moreover, the activity of antioxidant enzymes increased at first and then decreased along with increasement of air exposure time. The concentration of malondialdehyde (MDA) in hepatopancreas was significantly increased under the air exposure stress, while the bacterial infection further aggravated such oxidative damage. The transcriptome analysis exhibited that the stress- and immunity-related genes in hepatopancreas altered when response to the air exposure stress. This study could help uncover the mechanisms of aerial exposure stress responses in Procambarus clarkii.

Synthesis and evaluation of the antioxidant activity of new spiro-1,2,4-triazine derivatives applying Ag/Fe3O4/CdO@MWCNT MNCs as efficient organometallic nanocatalysts

We applied the Petasites hybridus rhizome water extract as green media so that Ag/Fe₃O₄/CdO@ multi-walled carbon nanotubes magnetic nanocomposites (Ag/Fe₃O₄/CdO@MWCNTs MNCs) could be prepared. We also evaluated its activity by using in the one-pot multicomponent reaction of acetophenones, diethyl oxalate, ammonium acetate, and activated carbonyl compounds such as ninhydrin, isatin and acenaphthylene-1,2-dione, and malononitrile and hydrazoyl chlorides in an aqueous medium at room temperature for the generation of spiro-1,2,4-triazines as new derivatives with tremendous output. Moreover, reducing organic pollutants from 4-nitrophenol (4-NP) was carried out by generating Ag/Fe₃O₄/CdO@MWCNTs in water at room temperature. The results displayed that Ag/Fe₃O₄/CdO@MWCNTs reduced pollutants of organic compounds in a short time. The synthesized spiro-1,2,4-triazines have NH and OH functional groups having acidic hydrogen with high antioxidant power. Also, the spiro-1,2,4-triazines exhibited antimicrobial ability. For this purpose, the disk diffusion method was applied and two kinds of bacteria, Gram-positive and Gram-negative, were employed for the analysis. Furthermore, we applied functional theory-based quantum chemical methods in order to better understand reaction mechanism density. To generate spiro-1,2,4-triazines, the applied process showed many properties such as reactions with short time, products with good yields, and simple extraction of catalyst from a mixture of reactions.

Ability of donkey sperm to tolerate cooling: Effect of extender base and removal of seminal plasma on sperm parameters and fertility rates in mares

Artificial insemination using cooled-transported semen has marked importance in equine breeding programs around the world, and the high value of mules has generated avid interest in donkey semen biotechnology. However, donkey semen cools poorly in commercially available equine extenders. Therefore, this study aimed to develop approaches to improve the ability of donkey semen to tolerate cooling. Ejaculates of seven donkeys (n = 21) were cooled at 5°C for 48 h in three different extenders (milk-based, SM; sodium caseinate-based, SC; or egg yolk-based, EY) in the presence or absence of seminal plasma (centrifugation, C). Sperm motility, plasma membrane integrity (PMI), plasma membrane stability (PMS), mitochondrial membrane potential (HMMP), intracellular hydrogen peroxide (H₂O₂), and intracellular superoxide (O2−) were assessed before, 24 h, and 48 h post-cooling. In addition, 15 mares (163 estrous cycles) were randomly inseminated with semen from two jacks (Jack 1, n = 90; Jack 2, n = 73) previously cooled for 24 h under one of the treatments (SM, SC, EY, SM-C, SC-C, or EY-C). Groups EY, SC-C, and EY-C (P < 0.05) demonstrated superior sperm analytical parameters to SM at 24 and 48 h. Centrifugation positively affected sperm analytical parameters in cooled donkey semen extended in SM and SC (P < 0.05). Mares bred with semen extended in SC (67%, 18/27), SC-C (89%, 24/27), EY (89%, 25/28), or EY-C (74%, 20/27) had significantly greater conception rates than mares bred with SM (33%, 9/27; P < 0.05). Mares bred with SM-C had intermediate conception rates (59%, 16/27). In conclusion, SC and EY improved the cooling ability and fertility of donkey semen in horse mares, and centrifugation positively affected donkey semen extended in SM.

Six-component synthesis and biological activity of novel spiropyridoindolepyrrolidine derivatives: A combined experimental and theoretical investigation

Petasites hybridus rhizome water extract was used as green media for the preparation of Ag/Fe₃O₄/CdO@multi-walled carbon nanotubes magnetic nanocomposites (Ag/Fe₃O₄/CdO@MWCNTs MNCs), and its activity was evaluated by using in the one-pot multicomponent reaction of isatins, acetyl chloride, secondary amines, vinilidene Meldrum’s acid, primary amines, and malononitrile in an aqueous medium at room temperature for the generation of spiropyridoindolepyrrolidine as new derivatives with tremendous output. In addition, organic pollutant reduction of 4-nitrophenol (4-NP) was carried out by generated Ag/Fe₃O₄/CdO@MWCNTs in water at room temperature. The results displayed that Ag/Fe₃O₄/CdO@MWCNTs were reduced as pollutants of organic compounds in a short time. The synthesized spiropyridoindolepyrrolidine has an NH₂ functional group that has acidic hydrogen and shows high antioxidant ability. Also, the spiropyridoindolepyrrolidine exhibited antimicrobial ability, and the method that is used for this purpose is the disk diffusion method, and two kinds of bacteria, Gram-positive and Gram-negative, were employed for this analysis. Also, to better understand the reaction mechanism density, functional theory-based quantum chemical methods have been applied. For the generation of spiropyridoindolepyrrolidine, the used process has many properties such as reactions with short time, product with good yields, and simple extraction of catalyst from the mixture of reaction.

Are Dental Caries Associated with Oxidative Stress in Saliva in Children and Adolescents? A Systematic Review

Background: This systematic review aimed to assess whether dental caries is associated with oxidative salivary stress. Methods: The searches were carried out in electronic databases, including PubMed, Scopus, Web of Science, the Cochrane Library, LILACS, OpenGrey, and Google Scholar, without restrictions on the date of publication and language. The acronym PECO was used, in which the participants (P) were children and adolescents exposed (E) to dental caries compared (C) to those without dental caries, with the outcome (O) of modulation of oxidative biochemical parameters. After the search retrieval, the duplicates were removed, and the articles were evaluated by title and abstract, following the inclusion and exclusion criteria. Then, the papers were read and thoroughly assessed. After selection, the risk of bias assessment and qualitative synthesis were performed using the Newcastle-Ottawa Scale (NOS) for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the level of evidence. Results: A total of 5790 studies were found, and 30 articles were considered eligible and were included for the qualitative synthesis and the level of evidence assessment. The studies showed an imbalance of the antioxidant and pro-oxidant parameters in individuals with dental caries, with primarily increases in both total antioxidant capacity and lipid peroxidation. Most articles showed a low risk of bias, having comparability as the main issue. When exploring through GRADE, a very low level of evidence was found. Conclusions: It was possible to observe an association between oxidative stress and dental caries, showing a disbalance of antioxidants and pro-oxidants, but the evidence level was still very low.

Reactive Oxygen Species and Long Non-Coding RNAs, an Unexpected Crossroad in Cancer Cells

Long non-coding RNAs (lncRNA) have recently been identified as key regulators of oxidative stress in several malignancies. The level of reactive oxygen species (ROS) must be constantly regulated to maintain cancer cell proliferation and chemoresistance and to prevent apoptosis. This review will discuss how lncRNAs alter the ROS level in cancer cells. We will first describe the role of lncRNAs in the nuclear factor like 2 (Nrf-2) coordinated antioxidant response of cancer cells. Secondly, we show how lncRNAs can promote the Warburg effect in cancer cells, thus shifting the cancer cell’s “building blocks” towards molecules important in oxidative stress regulation. Lastly, we explain the role that lncRNAs play in ROS-induced cancer cell apoptosis and proliferation.

Role of Nitric Oxide in Postharvest Senescence of Fruits

Nitric oxide (NO) acts as a gaseous signalling molecule and is considered to be a key regulator in the postharvest storage of fruits. Postharvest senescence is one of the most serious threats affecting the usage and economic value of fruits. Most recent studies have found that exogenous NO application can effectively improve the quality and prolong the shelf life of fruit postharvest by inhibiting postharvest diseases and alleviating chilling injury. Understanding the roles of NO is essential to elucidating how NO activates the appropriate set of responses to postharvest senescence. Here, we concluded that exogenous NO treatment alleviated senescence in postharvest fruit and attributed this to the following factors: (1) ethylene biosynthesis, (2) the antioxidant system, (3) polyamine metabolism and γ-aminobutyric acid (GABA) shunting, (4) cell wall metabolism, (5) sugar metabolism, (6) energy metabolism, (7) the CRT/DRE-binding factor (CBF) pathway and (8) S-nitrosylation. Moreover, crosstalk between NO and hydrogen sulfide (H₂S), hydrogen peroxide (H₂O₂), oxalic acid (OA), arginine (Arg), GATA or plant hormone abscisic acid (ABA), melatonin (MT), and methyl jasmonate (MeJA), along with the regulation of key genes, were found to be very important in responses to postharvest senescence. In this study, we focus on the recent knowledge concerning the alleviative effect of NO on postharvest senescence, covering ethylene biosynthesis, the antioxidant system and related gene and protein expression.

The diversity and ecology of Symbiodiniaceae: A traits-based review

Among the most successful microeukaryotes to form mutualisms with animals are dinoflagellates in the family Symbiodiniaceae. These photosynthetic symbioses drive significant primary production and are responsible for the formation of coral reef ecosystems but are particularly sensitive when environmental conditions become extreme. Annual episodes of widespread coral bleaching (disassociation of the mutualistic partnership) and mortality are forecasted from the year 2060 under current trends of ocean warming. However, host cnidarians and dinoflagellate symbionts display exceptional genetic and functional diversity, and meaningful predictions of the future that embrace this biological complexity are difficult to make. A recent move to trait-based biology (and an understanding of how traits are shaped by the environment) has been adopted to move past this problem. The aim of this review is to: (1) provide an overview of the major cnidarian lineages that are symbiotic with Symbiodiniaceae; (2) summarise the symbiodiniacean genera associated with cnidarians with reference to recent changes in taxonomy and systematics; (3) examine the knowledge gaps in Symbiodiniaceae life history from a trait-based perspective; (4) review Symbiodiniaceae trait variation along three abiotic gradients (light, nutrients, and temperature); and (5) provide recommendations for future research of Symbiodiniaceae traits. We anticipate that a detailed understanding of traits will further reveal basic knowledge of the evolution and functional diversity of these mutualisms, as well as enhance future efforts to model stability and change in ecosystems dependent on cnidarian-dinoflagellate organisms.

Cellular Bioenergetics: Experimental Evidence for Alcohol-induced Adaptations

At-risk alcohol use is associated with multisystemic effects and end-organ injury, and significantly contributes to global health burden. Several alcohol-mediated mechanisms have been identified, with bioenergetic maladaptation gaining credence as an underlying pathophysiological mechanism contributing to cellular injury. This evidence-based review focuses on the current knowledge of alcohol-induced bioenergetic adaptations in metabolically active tissues: liver, cardiac and skeletal muscle, pancreas, and brain. Alcohol metabolism itself significantly interferes with bioenergetic pathways in tissues, particularly the liver. Alcohol decreases states of respiration in the electron transport chain, and activity and expression of respiratory complexes, with a net effect to decrease ATP content. In addition, alcohol dysregulates major metabolic pathways, including glycolysis, the tricarboxylic acid cycle, and fatty acid oxidation. These bioenergetic alterations are influenced by alcohol-mediated changes in mitochondrial morphology, biogenesis, and dynamics. The review highlights similarities and differences in bioenergetic adaptations according to tissue type, pattern of (acute vs. chronic) alcohol use, and energy substrate availability. The compromised bioenergetics synergizes with other critical pathophysiological mechanisms, including increased oxidative stress and accelerates cellular dysfunction, promoting senescence, programmed cell death, and end-organ injury.

Methamphetamine signals transcription of IL1β and TNFα in a reactive oxygen species-dependent manner and interacts with HIV-1 Tat to decrease antioxidant defense mechanisms

Methamphetamine (Meth) abuse is a common HIV co-morbidity that is linked to aggravated Central Nervous System (CNS) inflammation, which accentuates HIV- associated neurological disorders, triggered both directly or indirectly by the drug. We used the well-established human innate immune macrophage cell line system (THP1) to demonstrate that Reactive Oxygen Species (ROS) immediately induced by Meth play a role in the increased transcription of inflammatory genes, in interaction with HIV-1 Tat peptide. Meth and Tat, alone and together, affect early events of transcriptional activity, as indicated by changes in RNA polymerase (RNAPol) recruitment patterns throughout the genome, via ROS-dependent and -independent mechanisms. IL1β (IL1β) and TNF α (TNFα), two genes with defining roles in the inflammatory response, were both activated in a ROS-dependent manner. We found that this effect occurred via the activation of the activator protein 1 (AP-1) comprising cFOS and cJUN transcription factors and regulated by the SRC kinase. HIV-1 Tat, which was also able to induce the production of ROS, did not further impact the effects of ROS in the context of Meth, but promoted gene activity independently from ROS, via additional transcription factors. For instance, HIV-1 Tat increased NFkB activation and activated gene clusters regulated by Tata box binding peptide, ING4 and IRF2. Importantly, HIV-1 Tat decreased the expression of anti-oxidant genes, where its suppression of the detoxifying machinery may contribute to the aggravation of oxidative stress induced by ROS in the context of Meth. Our results provide evidence of effects of Meth via ROS and interactions with HIV Tat that promote the transcription of inflammatory genes such as IL1β and TNFα.

Oxidative Stress, Genomic Integrity, and Liver Diseases

Excess reactive oxygen species production and free radical formation can lead to oxidative stress that can damage cells, tissues, and organs. Cellular oxidative stress is defined as the imbalance between ROS production and antioxidants. This imbalance can lead to malfunction or structure modification of major cellular molecules such as lipids, proteins, and DNAs. During oxidative stress conditions, DNA and protein structure modifications can lead to various diseases. Various antioxidant-specific gene expression and signal transduction pathways are activated during oxidative stress to maintain homeostasis and to protect organs from oxidative injury and damage. The liver is more vulnerable to oxidative conditions than other organs. Antioxidants, antioxidant-specific enzymes, and the regulation of the antioxidant responsive element (ARE) genes can act against chronic oxidative stress in the liver. ARE-mediated genes can act as the target site for averting/preventing liver diseases caused by oxidative stress. Identification of these ARE genes as markers will enable the early detection of liver diseases caused by oxidative conditions and help develop new therapeutic interventions. This literature review is focused on antioxidant-specific gene expression upon oxidative stress, the factors responsible for hepatic oxidative stress, liver response to redox signaling, oxidative stress and redox signaling in various liver diseases, and future aspects.

Antioxidant Effects of Curcumin Gel in Experimental Induced Diabetes and Periodontitis in Rats

This study aimed to evaluate the effect of curcumin gel on antioxidant marker level in experimental induced diabetes and periodontitis (EDP) in rats. Adult Wistar rats were randomized into five groups (20 each): (1) EDP treated with scaling and root planing (SRP) + curcumin gel (CU), (2) EDP treated with CU, (3) EDP treated with SRP, (4) EDP without treatment, and (5) systemically healthy and without ligature (control). Each group was subdivided equally into 4 subgroups of 5 rats. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ), and periodontitis was induced by a ligature. Blood samples were collected by cardiac puncture at 0, 7, 14, and 21 days to assess oxidative stress of malondialdehyde (MDA) and antioxidant enzymes of glutathione peroxidase (GPx), catalase (CAT), and suproxidase dismutase (SOD) levels. The results showed a significant increase in serum MDA and antioxidant enzyme levels in the untreated EDP group compared to the control group ( $p<0.05$ ). The adjuvant use of CU to SRP resulted in a significant reduction of MDA and CAT levels as compared to the SRP group ( $p<0.05$ ); however, significant reduction of GPX and SOD levels can be found only at day 7. It can be concluded that the decreased level of antioxidant enzymes can be construed as a result of decreased oxidative stress by curcumin therapy.

Methylsulfonylmethane relieves cobalt chloride-induced hypoxic toxicity in C2C12 myoblasts

AIMS

In biology and medicine, hypoxia refers to reduced oxygen tension or oxygen starvation resulting from various environmental or pathological conditions. Prolonged hypoxia may lead to an imbalance in protein production and a loss of muscle mass in animals. The physiological response to hypoxia includes oxidative stress-induced activation of complex cell-signaling networks such as hypoxia-inducible factor (HIF), phosphoinositide 3-kinase (PI3K), and Janus kinase/signal transducer and activator of transcription (JAK-STAT). Methylsulfonylmethane (MSM) is a natural sulfur compound that regulates HIF-1α expression and provides cytoprotection from oxidative stress. In this study, we explored the anti-hypoxic activity and cytoprotective effect of MSM in cobalt chloride (CoCl₂)-induced hypoxic C2C12 mouse myoblast culture.

MATERIALS AND METHODS

We used western blotting, real time PCR, flow cytometry for molecular signaling studies and we also used MTT assay and ChIP assay along with comet assay for cellular processes.

KEY FINDINGS

MSM prevented the CoCl₂ induced cytotoxicity. Molecular markers of hypoxia, induced by CoCl₂, were normalized or reduced by MSM, which also inhibited the effect of CoCl₂-induced JAK2/STAT5b/Cyclin D1 and PI3K/AKT signaling. CoCl₂-induced oxidative stress results in activation of the NRF2/HO-1-mediated cell survival pathway and inhibition of DNA repair, both of which were prevented by MSM.

SIGNIFICANCE

We suggest MSM can be considered as a candidate drug for reducing the effects of hypoxia in both animals and humans.

Green synthesis and investigation of antioxidant and antimicrobial activity of new schiff base of pyrimidoazepine derivatives: application of Fe3O4/CuO/ZnO@MWCNT MNCs as an efficient organometallic nanocatalyst

In this study, we synthesized schiff base of pyrimidoazepine derivatives in high yields using multicomponent reactions of isatins, alkyl bromides, activated acetylenic compounds, guanidine and aldehydes in the presence of Fe₃O₄/CuO/ZnO@ Multi Walled Carbon Nanotubes (MWCNT) as a high performance catalyst in water at room temperature. The Fe₃O₄/CuO/ZnO@MWCNT synthesizes using Petasites hybridus rhizome water extract as a green media and moderate base. As well Fe₃O₄/CuO/ZnO@MWCNT magnetic nanocomposites show a good improvement in the yield of the product and displayed significant reusable activity. Investigation of antioxidant ability of synthesized compounds using radical trapping of diphenyl-picrylhydrazine and ferric reduction power experiment is another purpose in this research. Also, the antimicrobial activity of some synthesized compounds proved by employing the disk diffusion test on Gram-positive and Gram-negative bacteria. This procedure has some benefits such as short reaction time, product with excellent yields, simple catalyst and products separation.

Green novel multicomponent synthesis and biological evaluation of new oxazolopyrazoloazepines and reduction of nitrophenols in the presence of Ag/Fe3O4/ZnO@MWCNT MNCs

In this research, new derivatives of oxazolopyrazoloazepines were synthesized in high yields using multicomponent reaction of anilines, oxalylchloride, alkyl bromides, activated acetylenic compounds, hydrazine and ethyl bromopyruvate in the presence of Ag/Fe₃O₄/ZnO@MWCNT magnetic nanocomposite (MNCs) as a high-performance magnetic catalyst in ionic liquid at room temperature. The Ag/Fe₃O₄/ZnO@MWCNT magnetic nanocomposites (MNCs) were synthesized using 1-octhyl-3-methyl imidazolium bromide ([OMIM]Br) as a stabilizer and soft template. Also, the catalytic activity of the Ag/Fe₃O₄/ZnO@MWCNT MNCs was evaluated in reduction of organic pollutants such as 4-nitrophenol (4-NP) in water at mild conditions. The results indicated that the biosynthesized nanocomposites (NCs) have high catalytic activity for organic pollutants within few seconds. Because of having benzazepine nucleus in the synthesized compounds, we investigate antioxidant property of some synthesized oxazolopyrazoloazepines by diphenyl-picrylhydrazine radical trapping and power of ferric reduction experiment. Short time of reaction, high yields of product, easy separation of catalyst and products are some advantages of this procedure.

Effects of Catalase on Growth Performance, Antioxidant Capacity, Intestinal Morphology, and Microbial Composition in Yellow Broilers

The objective of this experiment was to study the effects of catalase (CAT) on growth performance, antioxidant capacity, intestinal morphology, and microbial composition of yellow broilers. Male Lingnan yellow broilers (360), aged 1 day, were randomly divided into control group (CON) (fed with a basic diet), R1 group (fed with basic diet + 150 U/kg catalase), and R2 group (fed with basic diet + 200 U/kg catalase). Each group had 8 replicates and 15 chickens in each replicate. The test is divided into the early stage (1–30 days) and the later stage (31–60 days). The results showed that compared with the control group, groups R1 and R2 significantly (p < 0.05) increased the weight gain and reduced (p < 0.05) the ratio of feed to gain in the early and the whole stages; prominently increased (p < 0.05) the concentration of total antioxidant capacity (T-AOC), the activities of CAT, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in livers, the activities of CAT and GSH-Px in serum, and CAT in the jejunum in the early and the later stages; markedly increased (p < 0.05) the villus height and the ratio of villus height to crypt depth of the duodenum in the early and the later stages, the villus height and the villus height:crypt depth ratio of the jejunum and ileum in the early stage, and significantly lowered (p < 0.05) the crypt depth of the duodenum (in the early and the later stages), jejunum, and ileum (in early stage); memorably (p < 0.05) increased the number of total bacteria and Bacteroidetes in ceca, as well as the number of Lactobacillus in the jejunum (p < 0.05) on the 30th; significantly (p < 0.05) increased the mRNA expression of junction adhesion molecule 2 (JAM2), mucin 2 (MCU2), and occlusal protein (occludin) in the duodenum in the early stage, and increased (p < 0.05) the mRNA expression of JAM2 in the jejunum in the later stage. Collectively, adding catalase (CAT) to the diet of yellow broilers can improve the growth performance and the antioxidant capacity, promoting the integrity of intestinal morphology, optimizing the composition of intestinal microorganisms, and upregulating the mRNA expression of tight junction protein.

Vitamin Supplements as a Nutritional Strategy against Chronic Alcohol Consumption? An Updated Review

Several studies have shown that blood vitamin levels are low in alcoholic patients. In effect, alcohol use abuse is considered a chronic disease that promotes the pathogenesis of many fatal diseases, such as cancer and liver cirrhosis. The alcohol effects in the liver can be prevented by antioxidant mechanisms, which induces enzymatic as well as other nonenzymatic pathways. The effectiveness of several antioxidants has been evaluated. However, these studies have been accompanied by uncertainty as mixed results were reported. Thus, the aim of the present review article was to examine the current knowledge on vitamin deficiency and its role in chronic liver disease. Our review found that deficiencies in nutritional vitamins could develop rapidly during chronic liver disease due to diminished hepatic storage and that inadequate vitamins intake and alcohol consumption may interact to deplete vitamin levels. Numerous studies have described that vitamin supplementation could reduce hepatotoxicity. However, further studies with reference to the changes in vitamin status and the nutritional management of chronic liver disease are in demand.

A Dynamic Model for Estimating the Interaction of ROS–PUFA–Antioxidants in Rabbit

Defining optimal nutrition in animals and humans remains a main scientific challenge. The objective of the work was to develop a dynamic model of reactive oxygen species (ROS)–polyunsaturated fatty acid (PUFA)–antioxidant homeostasis using the rabbit as a model. The problem entity was to evaluate the main metabolites generated from interactions between traits included in the conceptual model and identified by three main sub–models: (i) ROS generation, (ii) PUFA oxidation and (iii) antioxidant defence. A mathematical model (VENSIM software) that consisted of molecular stocks (INPUTs, OUTPUTs), exchange flows (intermediate OUTPUTs) and process rates was developed. The calibration was performed by using standard experimental data (Experiment 1), whereas the validation was carried out in Experiments 2 and 3 by using supra–nutritional dietary inputs (VIT E+ and PUFA+). The accuracy of the models was measured using 95% confidence intervals. Analytical OUTPUTs (ROS, PUFA, Vit E, Ascorbic acid, Iso–/NeuroProstanes, Aldehydes) were well described by the standard model. There was also good accuracy for the VIT E+ scenario, whereas some compensatory rates (Kc1–Kc4) were added to assess body compensation when high levels of dietary PUFA were administered (Experiment 3). In conclusion, the model can be very useful for predicting the effects of dietary treatments on the redox homeostasis of rabbits.

Alcohol-Associated Tissue Injury: Current Views on Pathophysiological Mechanisms

At-risk alcohol use is a major contributor to the global health care burden and leads to preventable deaths and diseases including alcohol addiction, alcoholic liver disease, cardiovascular disease, diabetes, traumatic injuries, gastrointestinal diseases, cancers, and fetal alcohol syndrome. Excessive and frequent alcohol consumption has increasingly been linked to alcohol-associated tissue injury and pathophysiology, which have significant adverse effects on multiple organ systems. Extensive research in animal and in vitro models has elucidated the salient mechanisms involved in alcohol-induced tissue and organ injury. In some cases, these pathophysiological mechanisms are shared across organ systems. The major alcohol- and alcohol metabolite-mediated mechanisms include oxidative stress, inflammation and immunometabolic dysregulation, gut leak and dysbiosis, cell death, extracellular matrix remodeling, endoplasmic reticulum stress, mitochondrial dysfunction, and epigenomic modifications. These mechanisms are complex and interrelated, and determining the interplay among them will make it possible to identify how they synergistically or additively interact to cause alcohol-mediated multiorgan injury. In this article, we review the current understanding of pathophysiological mechanisms involved in alcohol-induced tissue injury.

GPX7 Is Targeted by miR-29b and GPX7 Knockdown Enhances Ferroptosis Induced by Erastin in Glioma

Background

Glioma is a lethal primary tumor of central nervous system. Ferroptosis is a newly identified form of necrotic cell death. Triggering ferroptosis has shown potential to eliminate aggressive tumors. GPX7, a member of glutathione peroxidase family (GPXs), has been described to participate in oxidative stress and tumorigenesis. However, the biological functions of GPX7 in glioma are still unknown.

Methods

Bioinformatics method was used to assess the prognostic role of GPX7 in glioma. CCK8, wound healing, transwell and cell apoptosis assays were performed to explore the functions of GPX7 in glioma cells. In vivo experiment was also conducted to confirm in vitro findings. Ferroptosis-related assays were carried out to investigate the association between GPX7 and ferroptosis in glioma.

Results

GPX7 was aberrantly expressed in glioma and higher expression of GPX7 was correlated with adverse outcomes. GPX7 silencing enhanced ferroptosis-related oxidative stress in glioma cells and the loss of GXP7 sensitized glioma to ferroptosis induced by erastin. Furthermore, we found that miR-29b directly suppressed GPX7 expression post-transcriptionally. Reconstitution of miR-29b enhanced erastin sensitivity, partly via GPX7 suppression.

Conclusions

Our study clarified the prognostic role of GPX7 in glioma and preliminarily revealed the role of GPX7 in ferroptosis, which may be conducive to the exploration of therapeutic targets of glioma.

Seed priming with brassinosteroids alleviates aluminum toxicity in rice via improving antioxidant defense system and suppressing aluminum uptake

Brassinosteroids (BRs) are growth-promoting hormones that exhibit high biological activities across various plant species. BRs shield plants against various abiotic stresses. In the present study, the effect of BRs against aluminum (Al) toxicity was investigated through seed priming with 24-epibrassinolide (0.01 μM) in two different rice cultivars. BRs application was found effective in confronting plants from Al toxicity (400 μM). The rice seeds primed with BRs showed enhancement in seed germination energy, germination percentage, root and shoot length, as well as fresh and dry weight under Al-absence and Al-stressed conditions as compared to water-priming. Especially under Al stress, BRs priming promoted the growth of rice seedlings more obviously. Al toxicity significantly increased the Al contents in seedling root and shoot, as well as the MDA concentration, H₂O₂ production, and the activities of antioxidative enzymes including ascorbate peroxidase, catalase, and peroxidase. Meanwhile, the photosynthetic pigments of seedling reduced under Al stress. When compared to sensitive cultivar (CY-927), these modifications were more obvious in the tolerant variety (YLY-689). Surprisingly, BRs were able to alleviate the Al injury by lowering MDA and H₂O₂ level and increasing antioxidant activities and photosynthetic pigments under Al stress. The results on antioxidant activities were further validated by gene expression study of SOD-Cu-Zn, SOD-Fe₂, CATa, CATb, APX02, and APX08. It suggested that BRs were responsible for the mitigation of Al stress in rice seedlings by inducing antioxidant activities with an effective response to other seed growth parameters and reduced Al uptake under induced metal stress.

Antioxidant Paradox in Male Infertility: 'A Blind Eye' on Inflammation

The pathophysiology of male infertility involves various interlinked endogenous pathways. About 50% of the cases of infertility in men are idiopathic, and oxidative stress (OS) reportedly serves as a central mechanism in impairing male fertility parameters. The endogenous antioxidant system operates to conserve the seminal redox homeostasis required for normal male reproduction. OS strikes when a generation of seminal reactive oxygen species (ROS) overwhelms endogenous antioxidant capacity. Thus, antioxidant treatment finds remarkable relevance in the case of idiopathic male infertility or subfertility. However, due to lack of proper detection of OS in male infertility, use of antioxidant(s) in some cases may be arbitrary or lead to overuse and induction of 'reductive stress'. Moreover, inflammation is closely linked to OS and may establish a vicious loop that is capable of disruption to male reproductive tissues. The result is exaggeration of cellular damage and disruption of male reproductive tissues. Therefore, limitations of antioxidant therapy in treating male infertility are the failure in the selection of specific treatments targeting inflammation and OS simultaneously, two of the core mechanisms of male infertility. The present review aims to elucidate the antioxidant paradox in male infertility treatment, from the viewpoints of both induction of reductive stress as well as overlooking the inflammatory consequences.

Protective effect of Myrcia pubipetala Miq. against the alterations in oxidative stress parameters in an animal model of depression induced by corticosterone

Depression is a debilitating disorder in humans that significantly affects quality of life. As such, alternative therapies are highly sought after by patients seeking treatment for depression. Experimentally, the chronic administration of corticosterone (CORT) in rodents has been reported to promote depressive-like behaviors. Herein, animals received saline or CORT for 21 days and, during the last 7 days, they were treated with the crude hydroalcoholic extract (CHE) of Myrcia pubipetala Miq (50, 100 or 150 mg/Kg), or vehicle (distilled water), by oral route. After 24 h, animals were subjected to the open field (OFT) and forced swimming tests (FST), and then sacrificed for the removal of the hippocampus and cerebral cortex for biochemical analysis. Results showed enhanced catalase (CAT) and superoxide dismutase (SOD) activities, as well as an elevated formation of thiobarbituric acid reactive substances (TBARS), in the cerebral cortex of CORT-treated mice. The chronic administration of the CHE (100 and 150 mg/Kg) reduced TBARS and the increased total sulfhydryl content, and also reversed the increase in TBARS induced by CORT. In the hippocampus, CORT increased CAT and SOD activities and reduced glutathione peroxidase (GSH-Px) (C) activity, while Myrcia pubipetala Miq. CHE (100 and 150 mg/Kg) increased GSH-Px activity when administered alone and reversed decreased GSH-Px (100 and 150 mg/Kg) activity when given during CORT administration. Neither CORT administration nor CHE treatment significantly altered the immobility time of the animals in FST and no changes were observed in the locomotor activity of the animals in the OFT. Findings indicate that the CHE of Myrcia pubipetala Miq. exerts antioxidant effects in the cerebral cortex and hippocampus of mice induced to depression by CORT. Since phenolic compounds are reported to have antioxidant effects in this species, the effects of the CHE may be, at least in part, mediated by the presence of these compounds in Myrcia extract.

Reductive Stress and Male Infertility

Male infertility research and clinical advances had vast progress in the last few decades. Strong research evidence underpinned the concepts of oxidative stress (OS)-mediated male reproductive disruptions, which bear answers to several cases of idiopathic male infertility. Antioxidant treatment held the prime solution for OS-mediated male infertility. But excess use of antioxidants is challenged by the research breakthrough that reductive stress also predisposes to male infertility, resolutely instituting that any biological extremes of the redox spectrum are deleterious to male fertility. Superfluity of reducing agents may hinder essential oxidation mechanisms, affecting physiological homeostasis. These mechanisms need to be explicated and updated time and again to identify the fine thread between OS-mediated male infertility treatment and induction of reductive stress. This chapter thus presents the evidence-based concepts pertaining to the antioxidants actions to combat OS-induced male infertility, the mechanism of induction of reductive stress and its impact on male reproduction.

Evaluation of the effect of nonsurgical periodontal therapy on malondialdehyde and 8-hydroxy deoxyguanosine levels in chronic periodontitis

Background

Reactive oxygen species released on stimulation by periodontal pathogens cause oxidation of biomolecules and play significant role in periodontal disease pathogenesis.

Aim

This study aimed to evaluate the levels of oxidative by-products malondialdehyde (MDA) and 8-hydroxy deoxyguanosine (8-OHdG) as biomarkers in chronic periodontitis patients compared to healthy as well as before and after nonsurgical periodontal therapy. The correlation between biomarkers and clinical attachment level was also evaluated.

Settings and Design

A total of 112 subjects were included in this study. The subjects were divided into two groups (Group I included 56 healthy subjects and Group II constituted 56 chronic periodontitis patients) on the basis of clinical periodontal parameters.

Materials and Methods

Group I subjects received no treatment and were evaluated once only for clinical and oxidative stress biomarker parameters. Nonsurgical periodontal therapy was carried out in Group II patients and they were evaluated at baseline and 3 months after therapy.

Results

Both salivary and serum levels of MDA and 8-OHdG were found to be increased in chronic periodontitis patients as compared to healthy subjects. After nonsurgical periodontal therapy, the levels of MDA and 8-OHdG significantly reduced. Linear correlation between clinical attachment level and oxidative stress parameters was found to be positive and highly significant.

Conclusion

It can be concluded that periodontal therapy is effective in improving the oxidative stress condition.

Comparative Analysis of Three Trypanosomatid Catalases of Different Origin

Most trypanosomatid flagellates do not have catalase. In the evolution of this group, the gene encoding catalase has been independently acquired at least three times from three different bacterial groups. Here, we demonstrate that the catalase of Vickermania was obtained by horizontal gene transfer from Gammaproteobacteria, extending the list of known bacterial sources of this gene. Comparative biochemical analyses revealed that the enzymes of V. ingenoplastis, Leptomonas pyrrhocoris, and Blastocrithidia sp., representing the three independent catalase-bearing trypanosomatid lineages, have similar properties, except for the unique cyanide resistance in the catalase of the latter species.

Employing of Fe3O4/CuO/ZnO@MWCNT MNCs in the solvent-free synthesis of new cyanopyrroloazepine derivatives and investigation of biological activity

In this research, we synthesized the Fe₃O₄/CuO/ZnO@MWCNT magnetic nanocomposites using water extract of Petasites hybridus rhizome, and the high performance of synthesized catalyst was confirmed by using in the solvent-free multicomponent reactions of isatoic anhydride, N-methylimidazole, alkyl bromides, activated acetylenic compounds and 2-aminoacetonitrile at ambient temperature for the production of new cyanopyrroloazepine derivatives in high yields. This catalyst could be used several times in these reactions and have main role in the yield of product. The synthesized cyanopyrroloazepines have NH groups in their structure and for this reason have good antioxidant activity. Also, employing Gram-positive and Gram-negative bacteria in the disk diffusion procedure confirmed some cyanopyrroloazepines antimicrobial effect. The results showed that synthesized cyanopyrroloazepine prevented the bacterial growth. This used process for preparation of new cyanopyrroloazepine has some improvements such as low reaction time, product with high yields, simple separation of catalyst and products.