Molecular targets of oxidative stress

Antioxidant Systems of Plant Pathogenic Fungi: Functions in Oxidative Stress Response and Their Regulatory Mechanisms

During the infection process, plant pathogenic fungi encounter plant-derived oxidative stress, and an appropriate response to this stress is crucial to their survival and establishment of the disease. Plant pathogenic fungi have evolved several mechanisms to eliminate oxidants from the external environment and maintain cellular redox homeostasis. When oxidative stress is perceived, various signaling transduction pathways are triggered and activate the downstream genes responsible for the oxidative stress response. Despite extensive research on antioxidant systems and their regulatory mechanisms in plant pathogenic fungi, the specific functions of individual antioxidants and their impacts on pathogenicity have not recently been systematically summarized. Therefore, our objective is to consolidate previous research on the antioxidant systems of plant pathogenic fungi. In this review, we explore the plant immune responses during fungal infection, with a focus on the generation and function of reactive oxygen species. Furthermore, we delve into the three antioxidant systems, summarizing their functions and regulatory mechanisms involved in oxidative stress response. This comprehensive review provides an integrated overview of the antioxidant mechanisms within plant pathogenic fungi, revealing how the oxidative stress response contributes to their pathogenicity.

Natural Antioxidants: An Effective Strategy for the Treatment of Alzheimer's Disease at the Early Stage

The critical role of oxidative stress in Alzheimer's disease (AD) has been recognized by researchers recently, and natural antioxidants have been demonstrated to have anti-AD activity in animal models, such as Ginkgo biloba extract, soy isoflavones, lycopene, and so on. This paper summarized these natural antioxidants and points out that natural antioxidants always have multiple advantages which are help to deal with AD, such as clearing free radicals, regulating signal transduction, protecting mitochondrial function, and synaptic plasticity. Based on the available data, we have created a relatively complete pathway map of reactive oxygen species (ROS) and AD-related targets and concluded that oxidative stress caused by ROS is the core of AD pathogenesis. In the prospect, we introduced the concept of a combined therapeutic strategy, termed "Antioxidant-Promoting Synaptic Remodeling," highlighting the integration of antioxidant interventions with synaptic remodeling approaches as a novel avenue for therapeutic exploration.

Antioxidant and Anti-Inflammatory Properties of Hydrolyzed Royal Jelly Peptide in Human Dermal Fibroblasts: Implications for Skin Health and Care Applications

Hydrolyzed royal jelly peptide (RJP) has garnered attention for its health-promoting functions. However, the potential applications of RJP in skincare have not been fully explored. In this study, we prepared RJP through the enzymatic hydrolysis of royal jelly protein with trypsin and investigated its antioxidant and anti-inflammatory properties on primary human dermal fibroblasts (HDFs). Our results demonstrate that RJP effectively inhibits oxidative damage induced by H2O2 and lipid peroxidation triggered by AAPH and t-BuOOH in HDFs. This effect may be attributed to the ability of RJP to enhance the level of glutathione and the activities of catalase and glutathione peroxidase 4, as well as its excellent iron chelating capacity. Furthermore, RJP modulates the NLRP3 inflammasome-mediated inflammatory response in HDFs, suppressing the mRNA expressions of NLRP3 and IL-1β in the primer stage induced by LPS and the release of mature IL-1β induced by ATP, monosodium urate, or nigericin in the activation stage. RJP also represses the expressions of COX2 and iNOS induced by LPS. Finally, we reveal that RJP exhibits superior antioxidant and anti-inflammatory properties over unhydrolyzed royal jelly protein. These findings suggest that RJP exerts protective effects on skin cells through antioxidative and anti-inflammatory mechanisms, indicating its promise for potential therapeutic avenues for managing oxidative stress and inflammation-related skin disorders.

Potential New Therapies "ROS-Based" in CLL: An Innovative Paradigm in the Induction of Tumor Cell Apoptosis

Chronic lymphocytic leukemia, in spite of recent advancements, is still an incurable disease; the majority of patients eventually acquire resistance to treatment through relapses. In all subtypes of chronic lymphocytic leukemia, the disruption of normal B-cell homeostasis is thought to be mostly caused by the absence of apoptosis. Consequently, apoptosis induction is crucial to the management of this illness. Damaged biological components can accumulate as a result of the oxidation of intracellular lipids, proteins, and DNA by reactive oxygen species. It is possible that cancer cells are more susceptible to apoptosis because of their increased production of reactive oxygen species. An excess of reactive oxygen species can lead to oxidative stress, which can harm biological elements like DNA and trigger apoptotic pathways that cause planned cell death. In order to upset the balance of oxidative stress in cells, recent therapeutic treatments in chronic lymphocytic leukemia have focused on either producing reactive oxygen species or inhibiting it. Examples include targets created in the field of nanomedicine, natural extracts and nutraceuticals, tailored therapy using biomarkers, and metabolic targets. Current developments in the complex connection between apoptosis, particularly ferroptosis and its involvement in epigenomics and alterations, have created a new paradigm.

The protective effects of naringenin, a citrus flavonoid, non-complexed or complexed with hydroxypropyl-β-cyclodextrin against multiorgan damage caused by neonatal endotoxemia

BACKGROUND

Endotoxemia is a severe and dangerous clinical syndrome that results in elevated morbidity, especially in intensive care units. Neonates are particularly susceptible to endotoxemia due to their immature immune systems. There are few effective treatments for neonatal endotoxemia. One group of compounds with potential in the treatment of neonatal inflammatory diseases such as endotoxemia is the flavonoids, mainly due to their antioxidant and anti-inflammatory properties. Among these, naringenin (NGN) is a citrus flavonoid which has already been reported to have anti-inflammatory, antioxidant, anti-nociceptive and anti-cancer effects. Unfortunately, its clinical application is limited by its low solubility and bioavailability. However, cyclodextrins (CDs) have been widely used to improve the solubility of nonpolar drugs and enhance the bioavailability of these natural products.

OBJECTIVE

We, therefore, aimed to investigate the effects of NGN non-complexed and complexed with hydroxypropyl-β-cyclodextrin (HPβCD) on neonatal endotoxemia injuries in a rodent model and describe the probable molecular mechanisms involved in NGN activities.

METHOD

We used exposure to a bacterial lipopolysaccharide (LPS) to induce neonatal endotoxemia in the mice.

RESULTS

It was found that NGN (100 mg/kg i.p.) exposure during the neonatal period reduced leukocyte migration and decreased pro-inflammatory cytokine (TNF-α, IL-1β and IL-6) levels in the lungs, heart, kidneys or cerebral cortex. In addition, NGN upregulated IL-10 production in the lungs and kidneys of neonate mice. The administration of NGN also enhanced antioxidant enzyme catalase and SOD activity, reduced lipid peroxidation and protein carbonylation and increased the reduced sulfhydryl groups in an organ-dependent manner, attenuating the oxidative damage caused by LPS exposure. NGN decreased ERK1/2, p38MAPK and COX-2 activation in the lungs of neonate mice. Moreover, NGN complexed with HPβCD was able to increase the animal survival rate.

CONCLUSION

NGN attenuated inflammatory and oxidative damage in the lungs, heart and kidneys caused by neonatal endotoxemia through the MAPK signaling pathways regulation. Our results show that NGN has beneficial effects against neonatal endotoxemia and could be useful in the treatment of neonatal inflammatory injuries.

Identification of crucial roles of transcription factor IhfA on high production of free fatty acids in Escherichia coli

Transcription factor engineering has unique advantages in improving the performance of microbial cell factories due to the global regulation of gene transcription. Omics analyses and reverse engineering enable learning and subsequent incorporation of novel design strategies for further engineering. Here, we identify the role of the global regulator IhfA for overproduction of free fatty acids (FFAs) using CRISPRi-facilitated reverse engineering and cellular physiological characterization. From the differentially expressed genes in the ihfAL- strain, a total of 14 beneficial targets that enhance FFAs production by above 20 % are identified, which involve membrane function, oxidative stress, and others. For membrane-related genes, the engineered strains obtain lower cell surface hydrophobicity and increased average length of membrane lipid tails. For oxidative stress-related genes, the engineered strains present decreased reactive oxygen species (ROS) levels. These gene modulations enhance cellular robustness and save cellular resources, contributing to FFAs production. This study provides novel targets and strategies for engineering microbial cell factories with improved FFAs bioproduction.

Glyphosate is Harmful to Early Life Stages of the Viviparous Fish Jenynsia Multidentata: Biochemical and Locomotor Effects

Glyphosate is the most widely used herbicide worldwide due to its efficacy in weed control in agriculture. This herbicide has been consistently detected in the aquatic environment, causing harmful consequences to nontarget organisms residing in agricultural regions. In this study, we assessed the effects of environmentally relevant concentrations of glyphosate (30-100 µg/L) on the early life stages of the viviparous fish Jenynsia multidentata through biochemical and locomotor endpoints. At 96 h of exposure, 30 and 65 µg/L glyphosate caused an increase in acetylcholinesterase (AChE) activity, and 65 µg/L glyphosate also augmented the levels of lipid peroxidation. Glyphosate at 100 µg/L did not alter the activity of acetylcholinesterase or the levels of lipid peroxidation, but it stimulated the activity of the cellular detoxification enzyme glutathione S-transferase. In addition, all concentrations affected the swimming of the fish. Under light conditions, glyphosate caused hypolocomotion at all concentrations tested, whereas under dark conditions, this was observed at 30 and 100 µg/L. Hyperlocomotion was observed at 65 µg/L glyphosate. These findings are alarming for the health of fish, such as J. multidentata that inhabit streams that pass through agricultural areas, especially for the early life stages of these fish. Research studying the effects of pollutants on native species is relevant to improve regulation that protects aquatic ecosystems.

Crucial aspects of metabolism and cell biology relating to industrial production and processing of Saccharomyces biomass

The multitude of applications to which Saccharomyces spp. are put makes these yeasts the most prolific of industrial microorganisms. This review considers biological aspects pertaining to the manufacture of industrial yeast biomass. It is proposed that the production of yeast biomass can be considered in two distinct but interdependent phases. Firstly, there is a cell replication phase that involves reproduction of cells by their transitions through multiple budding and metabolic cycles. Secondly, there needs to be a cell conditioning phase that enables the accrued biomass to withstand the physicochemical challenges associated with downstream processing and storage. The production of yeast biomass is not simply a case of providing sugar, nutrients, and other growth conditions to enable multiple budding cycles to occur. In the latter stages of culturing, it is important that all cells are induced to complete their current budding cycle and subsequently enter into a quiescent state engendering robustness. Both the cell replication and conditioning phases need to be optimized and considered in concert to ensure good biomass production economics, and optimum performance of industrial yeasts in food and fermentation applications. Key features of metabolism and cell biology affecting replication and conditioning of industrial Saccharomyces are presented. Alternatives for growth substrates are discussed, along with the challenges and prospects associated with defining the genetic bases of industrially important phenotypes, and the generation of new yeast strains."I must be cruel only to be kind: Thus bad begins, and worse remains behind." William Shakespeare: Hamlet, Act 3, Scene 4.

Evaluation of the effect of direct-acting antiviral agents on melatonin level and lipid peroxidation in chronic hepatitis C patients

Background: Oxidative stress and its end products, such as malondialdehyde (MDA) play a leading role in the pathogenesis of hepatitis C. Melatonin is a hormone that helps regulate circadian rhythms, which likely play a role in infectious diseases in terms of susceptibility, clinical expression, and outcome. Objective: The present study was conducted to assess serum malondialdehyde and melatonin levels in patients with chronic hepatitis C infection before and after the intake of direct-acting antivirals. Method: Forty hepatitis C patients were the subjects of this study. While ten healthy volunteers who matched in age and socioeconomic status served as the control subjects. Malondialdehyde and melatonin were assayed in the serum of the three groups, and the results were statistically analyzed. Results: Hepatitis C patients had significantly higher malondialdehyde (p < 0.001) but significantly lower melatonin (p < 0.001) as compared to the healthy controls. After 12 weeks of treatment with direct-acting antivirals, the malondialdehyde level decreased significantly (p < 0.001) and the melatonin level increased significantly (p < 0.001). A significant negative correlation between malondialdehyde and melatonin was observed. Conclusion: The present findings suggest that treatment of hepatitis C patients with Direct-acting antivirals improves liver function parameters and antioxidant profiles.

The effect of metalation on antimicrobial piscidins imbedded in normal and oxidized lipid bilayers

Metalation of the N-terminal Amino Terminal Cu(ii)- and Ni(ii)-binding (ATCUN) motif may enhance the antimicrobial properties of piscidins. Molecular dynamics simulations of free and nickelated piscidins 1 and 3 (P1 and P3) were performed in 3 : 1 POPC/POPG and 2.6 : 1 : 0.4 POPC/POPG/aldo-PC bilayers (POPC, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine: POPG, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol; aldo-PC, 1-palmitoyl-2-(9'-oxo-nonanoyl)-sn-glycero-3-phosphocholine) bilayer models. Nickel(ii) binding decreases the conformation dynamics of the ATCUN motif and lowers the charge of the N-terminus to allow it to embed deeper in the bilayer without significantly changing the overall depth due to interactions of the charged half-helix of the peptide with the headgroups. Phe1⋯Ni2+ cation-π and Phe2-Phe1 CH-π interactions contribute to a small fraction of structures within the nickelated P1 simulations and may partially protect a bound metal from metal-centered chemical activity. The substitution of Phe2 for Ile2 in P3 sterically blocks conformations with cation-π interactions offering less protection to the metal. This difference between metalated P1 and P3 may indicate a mechanism by which peptide sequence can influence antimicrobial properties. Any loss of bilayer integrity due to chain reversal of the oxidized phospholipid chains of aldo-PC may be enhanced in the presence of metalated piscidins.

Therapeutic Applications of Plant-Derived Extracellular Vesicles as Antioxidants for Oxidative Stress-Related Diseases

Extracellular vesicles (EVs) composed of a lipid bilayer are released from various cell types, including animals, plants, and microorganisms, and serve as important mediators of cell-to-cell communication. EVs can perform a variety of biological functions through the delivery of bioactive molecules, such as nucleic acids, lipids, and proteins, and can also be utilized as carriers for drug delivery. However, the low productivity and high cost of mammalian-derived EVs (MDEVs) are major barriers to their practical clinical application where large-scale production is essential. Recently, there has been growing interest in plant-derived EVs (PDEVs) that can produce large amounts of electricity at a low cost. In particular, PDEVs contain plant-derived bioactive molecules such as antioxidants, which are used as therapeutic agents to treat various diseases. In this review, we discuss the composition and characteristics of PDEVs and the appropriate methods for their isolation. We also discuss the potential use of PDEVs containing various plant-derived antioxidants as replacements for conventional antioxidants.

Genotoxic effects of polycyclic aromatic hydrocarbons (PAHs) present in vehicle-wash wastewater on grass carp (Ctenopharyngodon idella) and freshwater mussels (Anodonta cygnea)

Vehicle-wash wastewater (VWW) contains high levels of various petrochemicals such as polycyclic aromatic hydrocarbons (PAHs), a carcinogenic category of organic substances. However, the genotoxic effects of PAHs present in VWW remain largely unknown. We explored the genotoxic effects of PAHs present in VWW on fish grass carp (Ctenopharyngodon idella) and freshwater mussels (Anodonta cygnea). Fish and freshwater mussels were divided into control and exposed groups, the prior groups were treated at weekly intervals with clean water, and the latter with Σ16PAHs contaminated VWW for up to four weeks. The samples of blood from fish and haemolymph from freshwater mussels were collected and analyzed using the comet assay technique. Results exhibited that in control fish and freshwater mussel groups the genotoxicity decreased with every week passing following the order of W1 > W2 > W3 > W4, ranging from 8.33 ± 3.06 to 25.3 ± 4.62 and from 46.0 ± 6.93 to 7.67 ± 3.79, respectively. The exposed fish and freshwater mussel groups indicated an increase in genotoxicity with increasing week intervals with an order of W4 > W3 > W2 > W1, ranging from 55.7 ± 11.9 to 128.3 ± 10.0 and from 112.7 ± 8.50 to 183.3 ± 10.1, respectively. The genotoxic effect of Σ16PAHs on fish was comparatively lower than on freshwater mussels. This study elucidates that VWW is highly genotoxic and should be treated before discharging into aquatic ecosystems.

Reuse of treated urban wastewater on the growth and physiology of Medicago sativa L. cv. Gea and Petroselinum crispum L. cv. Commun: correlation with oxydative stress and DNA damage

The freshwater scarcity is one of the major environmental problems, which is why the water reuse has become a possible remedy to cope with the shortage of water needed for agriculture irrigation. This study focuses on the evaluation of the irrigation effect with treated effluent from wastewater treatment plant in Tunisia on parsley (Petroselinum crispum L. cv. Commun) used as human food and alfalfa (Medicago sativa L. cv. Gea) as animal food. In vitro germination test was conducted at different dilution levels of wastewater as rejected into the environment (25, 50, and 100%) and wastewater with further treatment (TWW). Results have shown that wastewater with dilution of 25% as well as TWW positively affected the physiological parameters in comparison with the dilutions 50 and 100%. However, the tap water (TW) applied as control treatment has shown the best effects. Oxidative stress evaluated by malondialdehyde (MDA) content was in agreement with the physiological results and showed that the most stressed seeds were those treated with the dilutions 50 and 100%. A pot trial was also conducted to evaluate the suitability of WW and TWW in comparison to TW. Results have shown that TWW is more adapted than WW for irrigation as an improvement of growth and physiological parameters was recorded. Oxidative stress assessed with MDA and proline content has shown that plants irrigated with WW significantly accumulate MDA and proline compared to TWW. The TW has shown the lowest values. DNA damage was evaluated by extraction and agarose gel electrophoresis. It has revealed degradation of DNA for plants irrigated with WW. According to these results, it can be concluded that TWW can be used for irrigation of plants destined for human or animal foods. So, it can be a hydric alternative to resolve the problem of water deficit in semi-arid countries.

Selenium Alleviates Ammonia-Induced Splenic Cell Apoptosis and Inflammation by Regulating the Interleukin Family/Death Receptor Axis and Nrf2 Signaling Pathway

Ammonia (NH₃) is a harmful gas in livestock houses. So far, many researchers have demonstrated that NH₃ is detrimental to animal and human organs. Selenium (Se) is one of the essential trace elements in the body and has a good antioxidant effect. However, there was little conclusive evidence that Se alleviated NH₃ poisoning. To investigate the toxic mechanism of NH₃ on pig spleen and the antagonistic effect of L-selenomethionine, a porcine NH₃-poisoning model and an L-selenomethionine intervention model were established in this study. Our results showed that NH₃ exposure increased the apoptosis rate, while L-selenomethionine supplementation alleviated the process of excessive apoptosis. Immunofluorescence staining, real-time quantitative polymerase chain reaction (qRT-PCR), and western blot results confirmed that exposure to NH₃ changed the expression levels of interleukin family factors, apoptosis, death receptor, and oxidative stress factors. Our study further confirmed that excessive NH₃ induced inflammatory response and mediated necroptosis leading to cell apoptosis by activating the Nrf2 signaling pathway. Excessive NH₃ could mediate spleen injury through oxidative stress-induced mitochondrial dynamics disorder. L-Selenomethionine could alleviate inflammation and abnormal apoptosis by inhibiting the IL-17/TNF-α/FADD axis. Our study would pave the way for comparative medicine and environmental toxicology.

Carbonylated Proteins as Key Regulators in the Progression of Metabolic Syndrome

Based on the known role of oxidative stress in the pathogenesis and progression of metabolic syndrome, we used two-dimensional gel electrophoresis with immunochemical detection of protein carbonyls (2D-Oxyblot) to characterize the carbonylated proteins induced by oxidative stress in spontaneously hypertensive rats/NDmcr-cp (CP), an animal model of metabolic syndrome. We also profiled the proteins that showed change of expression levels in their epididymal adipose tissue at the pre-symptomatic (6-week-old) and the symptomatic (25-week-old) stages of the metabolic syndrome. Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS) was used to analyze proteins extracted from the epididymal adipose tissue. The up-regulated proteins identified at the pre-symptomatic stage were mainly associated with ATP production and redox reaction, while the down-regulated proteins found at the symptomatic stage were involved in antioxidant activity and the tricarboxylic acid (TCA) cycle. Further analysis using the 2D-Oxyblot showed significantly high carbonylation levels of gelsolin and glycerol-3-phosphate dehydrogenase [NAD+] at the symptomatic stage. These results suggest that reduced antioxidant capacity underlies the increased oxidative stress state in the metabolic syndrome. The identified carbonylated proteins, including gelsolin, are potential targets that may act as key regulators in the progression of the metabolic syndrome.

Dysfunctional mitochondria accumulate in a skeletal muscle knockout model of Smn1, the causal gene of spinal muscular atrophy

The approved gene therapies for spinal muscular atrophy (SMA), caused by loss of survival motor neuron 1 (SMN1), greatly ameliorate SMA natural history but are not curative. These therapies primarily target motor neurons, but SMN1 loss has detrimental effects beyond motor neurons and especially in muscle. Here we show that SMN loss in mouse skeletal muscle leads to accumulation of dysfunctional mitochondria. Expression profiling of single myofibers from a muscle specific Smn1 knockout mouse model revealed down-regulation of mitochondrial and lysosomal genes. Albeit levels of proteins that mark mitochondria for mitophagy were increased, morphologically deranged mitochondria with impaired complex I and IV activity and respiration and that produced excess reactive oxygen species accumulated in Smn1 knockout muscles, because of the lysosomal dysfunction highlighted by the transcriptional profiling. Amniotic fluid stem cells transplantation that corrects the SMN knockout mouse myopathic phenotype restored mitochondrial morphology and expression of mitochondrial genes. Thus, targeting muscle mitochondrial dysfunction in SMA may complement the current gene therapy.

Antioxidant Activity of Different Tissues from Rabbits Fed Dietary Bovine Colostrum Supplementation

Recent advances in animal nutrition have indicated that bovine colostrum (BC), due to its content of macronutrients, micronutrients and bioactive compounds, is an excellent health supplement. To the best of our knowledge, no studies on the effect of BC on antioxidant status have been performed in rabbits. This study aimed to investigate the effect of two BC concentrations on antioxidant status and gene expression of antioxidant enzymes in some tissues of rabbits. Thirty New Zealand White male rabbits were randomly divided into three experimental diets, containing 0% (CON), 2.5%, and 5% of BC (BC-2.5 and BC-5, respectively). The activity of antioxidant enzymes in plasma (catalase: CAT; glutathione peroxidase: GPx; superoxide dismutase: SOD), and the enzymes' gene expression in the liver and longissimus dorsi muscle, were determined. Results showed no significant differences, neither in plasma nor in tissues. A significant tissue-related effect has been observed regarding the mRNA levels of SOD and GPx, which were higher in the LD (p = 0.022) and liver (p = 0.001), respectively. Further studies, considering modifications of the length and dosage of dietary BC supplementation, are required to update the current state of knowledge in rabbits, as well as to fully understand the potential value of BC for possible application in farming use.

Effect of total glycosides of Cistanche deserticola on the energy metabolism of human HepG2 cells

To study the anti-tumor effect of Cistanche deserticola Y. Ma, HepG2 cells were treated with 0, 3.5, 10.5, 21, 31.5, and 42 μg/ml of total glycosides (TG) from Cistanche deserticola. The HepG2 cell survival rate and 50% inhibition concentration (IC₅₀) were detected using the CCK-8 method, and the level of reactive oxygen species (ROS) was detected by using a DCFH-DA fluorescence probe. Finally, a Seahorse XFe24 energy analyzer (Agilent, United States) was used to detect cell mitochondrial pressure and glycolytic pressure. The results showed that TG could reduce the survival rate of HepG2 cells and that the IC₅₀ level was 35.28 μg/ml. With increasing TG concentration, the level of ROS showed a concentration-dependent upward trend. Energy metabolism showed that each dose group of TG could significantly decline the mitochondrial respiratory and glycolytic functions of HepG2 cells. In conclusion, TG could significantly inhibit the mitochondrial respiration and glycolysis functions of HepG2 cells, increase the level of ROS, and inhibit cell proliferation. Thus, this experiment pointed out that Cistanche deserticola can be used as a source of anti-cancer foods or drugs in the future. However, further studies on its mechanisms and clinical applications are needed.

Volatile and Non-Volatile Content Determination and Biological Activity Evaluation of Fresh Humulus lupulus L. (cv. Chinook) Leaves and Inflorescences

In this work, the fresh leaves and inflorescences of Humulus lupulus L. cv. Chinook hops were investigated in order to describe their chemical composition and evaluate their biological activities. The analyses were carried out first on fresh untreated samples and then on pulverized ones using the SPME-GC-MS technique. In total, forty-two molecules belonging to different chemical classes were identified, and among these, twenty-three were terpene compounds. In order to carry out the activity assays, the powders were subjected to extraction with two different solvents (methanol and distilled water) by stirring and subsequent sonication at room temperature. To chemically characterize the extracts, the methanolic ones were analyzed by direct injection into the GC-MS apparatus, while the aqueous ones were analyzed by DI-SPME-GC-MS. In addition, with the aim to obtain information on the non-volatile content of the methanolic extracts, they were also subjected to derivatization, and the silylated derivatives were analyzed by GC-MS. The antioxidant activity was then evaluated by means of DPPH and ABTS assays after the determination of the total content of polyphenols and flavonoids. The greatest effects were observed on the methanolic extracts rather than on the aqueous ones. Furthermore, a preliminary study on the cytotoxic power of the methanolic extracts was also conducted on three different human cancer cell lines, such as non-small cell lung cancer (H1299), melanoma (A375) and breast cancer (MCF7). The obtained results showed that the two extracts induced a marginal effect on reducing breast tumor, melanoma and non-small cell lung cancer cell proliferation.

Curcumin and cinnamon mitigates lead acetate-induced oxidative damage in the spleen of rats

Lead toxicity is a common occupational and environmental health hazard that exerts many toxic effects on animals and humans, including immunotoxicity. Curcumin (CUR) and cinnamon (CIN) are common medicinal herbs with immunostimulatory and antioxidant properties. Therefore, this study investigated the protective effect of curcumin and cinnamon against lead acetate (LA)-induced splenotoxicity in rats via hemato-biochemical, immunological, oxidative stress marker, CYP-2E1 expression, histological, and immunohistological evaluations. Four groups of seven rats each were used: the control group received corn oil as a vehicle; the lead acetate group received (100 mg/kg), the CUR + LA group received curcumin (400 mg/kg) plus lead acetate, and the CIN + LA group received cinnamon (200 mg/kg) plus lead acetate orally for 1 month. LA exposure induced macrocytic hypochromic anemia, leukocytosis, neutrophilia, monocytosis, and lymphopenia. Additionally, significant elevations in serum iron, ferritin levels, and transferrin saturation percentage with significant decline of total and unsaturated iron binding capacities (TIBC and UIBC), transferrin, and immunoglobulin G and M levels were recorded. In addition, lead acetate significantly upregulated splenic CYP-2E1 expression, that was evident by significant depletion of reduced glutathione (GSH) activity and elevation of malondihyde (MDA), nitric oxide (NO), and protein carbonyl (PC) concentrations in the spleen. Histologically, hyperplasia of lymphoid follicles, hemosiderin deposition, and disturbance of CD3 and CD68 immuno-expressions were evident in the spleen from the lead acetate group. However, curcumin and cinnamon administration restored the hemato-biochemical, immunological, and oxidative stress parameters as well as histological and immunohistological pictures toward normalcy. In conclusion, curcumin and cinnamon can partially ameliorate LA-induced oxidative damage in the spleen, possibly through their antioxidant, immunomodulatory, and gene-regulating activities.

Metabolomic Study of Urine from Workers Exposed to Low Concentrations of Benzene by UHPLC-ESI-QToF-MS Reveals Potential Biomarkers Associated with Oxidative Stress and Genotoxicity

Benzene is a human carcinogen whose exposure to concentrations below 1 ppm (3.19 mg·m^-3) is associated with myelotoxic effects. The determination of biomarkers such as trans-trans muconic acid (AttM) and S-phenylmercapturic acid (SPMA) show exposure without reflecting the toxic effects of benzene. For this reason, in this study, the urinary metabolome of individuals exposed to low concentrations of benzene was investigated, with the aim of understanding the biological response to exposure to this xenobiotic and identifying metabolites correlated with the toxic effects induced by it. Ultra-efficient liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometer (UHPLC-ESI-Q-ToF-MS) was used to identify metabolites in the urine of environmentally (n = 28) and occupationally exposed (n = 32) to benzene (mean of 22.1 μg·m^-3 and 31.8 μg·m^-3, respectively). Non-targeted metabolomics analysis by PLS-DA revealed nine urinary metabolites discriminating between groups and statistically correlated with oxidative damage (MDA, thiol) and genetic material (chromosomal aberrations) induced by the hydrocarbon. The analysis of metabolic pathways revealed important alterations in lipid metabolism. These results point to the involvement of alterations in lipid metabolism in the mechanisms of cytotoxic and genotoxic action of benzene. Furthermore, this study proves the potential of metabolomics to provide relevant information to understand the biological response to exposure to xenobiotics and identify early effect biomarkers.

Impaired energy metabolism and altered functional activity of alveolar type II epithelial cells following exposure of rats to nitrogen mustard

Nitrogen mustard (NM) is a cytotoxic vesicant known to cause acute lung injury which progresses to fibrosis. Alveolar Type II cells are primarily responsible for surfactant production; they also play a key role in lung repair following injury. Herein, we assessed the effects of NM on Type II cell activity. Male Wistar rats were administered NM (0.125 mg/kg) or PBS control intratracheally. Type II cells, lung tissue and BAL were collected 3 d later. NM exposure resulted in double strand DNA breaks in Type II cells, as assessed by expression of γH2AX; this was associated with decreased expression of the DNA repair protein, PARP1. Expression of HO-1 was upregulated and nitrotyrosine residues were noted in Type II cells after NM exposure indicating oxidative stress. NM also caused alterations in Type II cell energy metabolism; thus, both glycolysis and oxidative phosphorylation were reduced; there was also a shift from a reliance on oxidative phosphorylation to glycolysis for ATP production. This was associated with increased expression of pro-apoptotic proteins activated caspase-3 and -9, and decreases in survival proteins, β-catenin, Nur77, HMGB1 and SOCS2. Intracellular signaling molecules important in Type II cell activity including PI3K, Akt2, phospho-p38 MAPK and phospho-ERK were reduced after NM exposure. This was correlated with dysregulation of surfactant protein production and impaired pulmonary functioning. These data demonstrate that Type II cells are targets of NM-induced DNA damage and oxidative stress. Impaired functioning of these cells may contribute to pulmonary toxicity caused by mustards.

Scavenging Reactive Oxygen Species Decreases Amyloid-β Levels via Activation of PI3K/Akt/GLUT1 Pathway in N2a/APP695swe Cells

Background: Dysregulated glucose metabolism in the brain is considered to be one of the key causes of Alzheimer’s disease (AD). Abnormal glucose uptake in AD is tightly associated with decreased levels of glucose transporter 1 (GLUT1) and GLUT3 in the brain, but the underlying mechanisms remain unclear. Objective: We aimed to explore the cause and mechanism of impaired glucose uptake in AD. Methods: N2a/WT and N2a/APP695swe cells were cultured in vitro, and cellular glucose uptake and ATP content, as well as the expression of GLUT1, GLUT3, and PI3K/Akt pathway members, were detected. Intracellular reactive oxygen species (ROS) levels were detected by flow cytometry. After treatment with the ROS scavenger N-acetyl-L-cysteine (NAC), the above indicators were detected again. Results: GLUT1 expression was significantly decreased (p = 0.0138) in N2a/APP695swe cells, while GLUT3 expression was no statistical difference (p >  0.05). After NAC treatment, PI3K and Akt phosphorylation levels, GLUT1 expression, glucose uptake and ATP levels were remarkably increased (p = 0.0006, p = 0.0008, p = 0.0009, p = 0.0001, p = 0.0013), while Aβ levels were significantly decreased (p = 0.0058, p = 0.0066). After addition of the PI3K inhibitor LY29004, GLUT1 expression was reduced (p = 0.0008), and Aβ levels were increased (p = 0.0009, p = 0.0117). In addition, increases in glucose uptake and ATP levels induced by the Akt activator SC79 were hindered by the GLUT1 inhibitor WZB117 (p = 0.0002, p = 0.0005). Aβ levels were decreased after SC79 treatment and increased after WZB117 treatment (p = 0.0212, p = 0.0006). Conclusion: Taken together, scavenging of ROS prevents from Aβ deposition via activation of the PI3K/Akt/GLUT1 pathway, and improved the impaired glucose uptake in N2a/APP695swe cells.

- Amphotericin B: A drug of choice for Visceral Leishmaniasis

Visceral leishmaniasis or Kala-azar is a vector-borne disease caused by an intracellular parasite of the genus leishmania. In India, Amphotericin B (AmB) is a first-line medication for treating leishmaniasis. After a large-scale resistance to pentavalent antimony therapy developed in Bihar state, it was rediscovered as an effective treatment for Leishmania donovani infection. AmB which binds to the ergosterol of protozoan cells causes a change in membrane integrity resulting in ions leakage, and ultimately leading to cell death. The treatment effect of liposomal AmB can be seen more quickly than deoxycholate AmB because, it has some toxic effects, but liposomal AmB is significantly less toxic. Evidence from studies suggested that ABLC (Abelcet) and ABCD (Amphotec) are as effective as L-AmB but Liposomal form (Ambisome) is a more widely accepted treatment option than conventional ones. Nevertheless, the world needs some way more efficient antileishmanial drugs that are less toxic and less expensive for people living with parasitic infections caused by Leishmania. So, academics, researchers, and sponsors need to focus on finding such drugs. This review provides a summary of the chemical, pharmacokinetic, drug-target interactions, stability, dose efficacy, and many other characteristics of the AmB and their various formulations. We have also highlighted the clinically significant aspects of PKDL and VL co-infection with HIV/TB.

The mitochondrial unfolded protein response (UPRmt): shielding against toxicity to mitochondria in cancer

Mitochondria are essential for tumor growth and progression. However, the heavy demand for mitochondrial activity in cancer leads to increased production of mitochondrial reactive oxygen species (mtROS), accumulation of mutations in mitochondrial DNA, and development of mitochondrial dysfunction. If left unchecked, excessive mtROS can damage and unfold proteins in the mitochondria to an extent that becomes lethal to the tumor. Cellular systems have evolved to combat mtROS and alleviate mitochondrial stress through a quality control mechanism called the mitochondrial unfolded protein response (UPR^mt). The UPR^mt system is composed of chaperones and proteases, which promote protein folding or eliminate mitochondrial proteins damaged by mtROS, respectively. UPR^mt is conserved and activated in cancer in response to mitochondrial stress to maintain mitochondrial integrity and support tumor growth. In this review, we discuss how mitochondria become dysfunctional in cancer and highlight the tumor-promoting functions of key components of the UPR^mt.

Unique thiol metabolism in trypanosomatids: Redox homeostasis and drug resistance

Trypanosomatids are mainly responsible for heterogeneous parasitic diseases: Leishmaniasis, Sleeping sickness, and Chagas disease and control of these diseases implicates serious challenges due to the emergence of drug resistance. Redox-active biomolecules are the endogenous substances in organisms, which play important role in the regulation of redox homeostasis. The redox-active substances like glutathione, trypanothione, cysteine, cysteine persulfides, etc., and other inorganic intermediates (hydrogen peroxide, nitric oxide) are very useful as defence mechanism. In the present review, the suitability of trypanothione and other essential thiol molecules of trypanosomatids as drug targets are described in Leishmania and Trypanosoma. We have explored the role of tryparedoxin, tryparedoxin peroxidase, ascorbate peroxidase, superoxide dismutase, and glutaredoxins in the anti-oxidant mechanism and drug resistance. Up-regulation of some proteins in trypanothione metabolism helps the parasites in survival against drug pressure (sodium stibogluconate, Amphotericin B, etc.) and oxidative stress. These molecules accept electrons from the reduced trypanothione and donate their electrons to other proteins, and these proteins reduce toxic molecules, neutralize reactive oxygen, or nitrogen species; and help parasites to cope with oxidative stress. Thus, a better understanding of the role of these molecules in drug resistance and redox homeostasis will help to target metabolic pathway proteins to combat Leishmaniasis and trypanosomiases.

Tigecycline and Gentamicin-Combined Treatment Enhances Renal Damage: Oxidative Stress, Inflammatory Reaction, and Apoptosis Interplay

Although the combination of antibiotics is generally well-tolerated, they may have nephrotoxic effects. This study investigated whether tigecycline (TG) and gentamicin (GM) co-administration could accelerate renal damage. Male Wistar rats were randomly divided into six experimental groups: the control, TG7 (tigecycline, 7 mg/kg), TG14 (tigecycline, 14 mg/kg), GM (gentamicin, 80 mg/kg), TG7+GM, and TG14+GM groups. The combination of TG and GM evoked renal damage seen by the disruption of kidney function tests. The perturbation of renal tissue was mainly confounded to the TG and GM-induced oxidative damage, which was exhibited by marked increases in renal MDA (malondialdehyde) along with a drastic reduction in GSH (reduced-glutathione) content and CAT (catalase) activity compared to their individual treatments. More obvious apoptotic events and inflammation were also revealed by elevating the annexin-V and interleukin-6 (IL-6) levels, aside from the upregulation of renal PCNA (proliferating cell nuclear antigen) expression in the TG and GM concurrent treatment. The principal component analysis indicated that creatinine, urea, annexin-V, IL-6, and MDA all played a role in discriminating the TG and GM combined toxicity. Oxidative stress, inflammatory response, and apoptosis were the key mechanisms involved in this potentiated toxicity.

An Overview of Oxidative Stress, Neuroinflammation, and Neurodegenerative Diseases

Oxidative stress has been linked with a variety of diseases, being involved in the debut and/or progress of several neurodegenerative disorders. This review intends to summarize some of the findings that correlate the overproduction of reactive oxygen species with the pathophysiology of Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis. Oxidative stress was also noted to modify the inflammatory response. Even though oxidative stress and neuroinflammation are two totally different pathological events, they are linked and affect one another. Nonetheless, there are still several mechanisms that need to be understood regarding the onset and the progress of neurodegenerative diseases in order to develop efficient therapies. As antioxidants are a means to alter oxidative stress and slow down the symptoms of these neurodegenerative diseases, the most common antioxidants, enzymatic as well as non-enzymatic, have been mentioned in this paper as therapeutic options for the discussed disorders.

Liquid Crystal Nanoparticle Conjugates for Scavenging Reactive Oxygen Species in Live Cells

The elevated intracellular production of or extracellular exposure to reactive oxygen species (ROS) causes oxidative stress to cells, resulting in deleterious irreversible biomolecular reactions (e.g., lipid peroxidation) and disease progression. The use of low-molecular weight antioxidants, such as 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), as ROS scavengers fails to achieve the desired efficacy because of their poor or uncontrolled cellular uptake and off-target effects, such as dysfunction of essential redox homeostasis. In this study, we fabricated a liquid crystal nanoparticle (LCNP) conjugate system with the fluorescent dye perylene (PY) loaded in the interior and poly (ethylene glycol) (PEG) decorated on the surface along with multiple molecules of TEMPO (PY-LCNP-PEG/TEMPO). PY-LCNP-PEG/TEMPO exhibit enhanced cellular uptake, and efficient ROS-scavenging activity in live cells. On average, the 120 nm diameter PY-LCNPs were conjugated with >1800 molecules of TEMPO moieties on their surface. PY-LCNP-PEG/TEMPO showed significantly greater reduction in ROS activity and lipid peroxidation compared to free TEMPO when the cells were challenged with ROS generating agents, such as hydrogen peroxide (H2O2). We suggest that this is due to the increased local concentration of TEMPO molecules on the surface of the PY-LCNP-PEG/TEMPO NPs, which efficiently bind to the plasma membrane and enter cells. Overall, these results demonstrate the enhanced capability of TEMPO-conjugated LCNPs to protect live cells from oxidative stress by effectively scavenging ROS and reducing lipid peroxidation.

Micronized Curcumin Causes Hyperlocomotion in Zebrafish Larvae

Zebrafish larvae have been widely used in neuroscience and drug research and development. In the larval stage, zebrafish present a broad behavioral repertoire and physiological responses similar to adults. Curcumin (CUR), a major component of Curcuma longa L. (Zingiberaceae), has demonstrated the ability to modulate several neurobiological processes relevant to mental disorders in animal models. However, the low bioavailability of this compound can compromise its in vivo biological potential. Interestingly, it has been shown that micronization can increase the biological effects of several compounds. Thus, in this study, we compared the effects of acute exposure for 30 min to the following solutions: water (control), 0.1% DMSO (vehicle), 1 μM CUR, or 1 μM micronized curcumin (MC) in zebrafish larvae 7 days post-fertilization (dpf). We analyzed locomotor activity (open tank test), anxiety (light/dark test), and avoidance behavior (aversive stimulus test). Moreover, we evaluated parameters of oxidative status (thiobarbituric acid reactive substances and non-protein thiols levels). MC increased the total distance traveled and absolute turn angle in the open tank test. There were no significant differences in the other behavioral or neurochemical outcomes. The increase in locomotion induced by MC may be associated with a stimulant effect on the central nervous system, which was evidenced by the micronization process.

Thymol protects against 6-hydroxydopamine-induced neurotoxicity in in vivo and in vitro model of Parkinson's disease via inhibiting oxidative stress

Background

Parkinson’s disease (PD) is a multifactorial movement disorder with the progressive degeneration of the nigrostriatal system that impairs patients’ movement ability. Oxidative stress has been found to affect the etiology and pathogenesis of PD. Thymol, a monoterpenic phenol, is one of the most important dietary constituents in thyme species. It has been used in traditional medicine and possesses some properties including antioxidant, free radical scavenging, anti-inflammatory. In this study, in vitro and in vivo experiments were performed with the thymol in order to investigate its potential neuroprotective effects in models of PD.

Methods

The present study aimed to evaluate the therapeutic potential of thymol in 6-hydroxydopamine (6-OHDA)-induced cellular and animal models of PD. 

Results

Post-treatment with thymol in vitro was found to protect PC12 cells from toxicity induced by 6-OHDA administration in a dose-dependent manner by (1) increasing cell viability and (2) reduction in intracellular reactive oxygen species, intracellular lipid peroxidation, and annexin-positive cells. In vivo, post-treatment with thymol was protective against neurodegenerative phenotypes associated with systemic administration of 6-OHDA. Results indicated that thymol improved the locomotor activity, catalepsy, akinesia, bradykinesia, and motor coordination and reduced the apomorphine-caused rotation in 6-OHDA-stimulated rats. Increased level of reduced glutathione content and a decreased level of MDA (malondialdehyde) in striatum were observed in the 6-OHDA rats post-treated with thymol.

Conclusions

Collectively, our findings suggest that thymol exerts protective effects, possibly related to an anti-oxidation mechanism, in these in vitro and in vivo models of Parkinson’s disease.

Autophagy and Oxidative Balance Mediate the Effect of Carvedilol and Glibenclamide in a Rat Model of Renal Ischemia-Reperfusion Injury

BACKGROUND: Reactive oxygen species and cytokines are the main players in the development of renal ischemia-reperfusion (I/R) injury. AIM: The current study aimed to evaluate the effects of carvedilol and/or glibenclamide and the interaction between autophagy and oxidative stress. METHODS: 50 male rats were divided into five groups: Control, IR injury (IRI), carvedilol pretreated, glibenclamide pretreated, and combined carvedilol and glibenclamide pretreated. Measurements of renal blood flow (RBF), creatinine clearance, serum blood urea nitrogen (BUN), histopathological, and immunohistochemical evaluation of autophagy marker Becl-1 in the rat kidney were performed. Beclin-1and light chain 3 (LC3) Mrna expression was detected by real time polymerase chain reaction. RESULTS: IRI was associated with significant increases in BUN, tumor necrosis factor-alpha, nuclear factor κB, and histo (H) score value of Becl-1. However, there was a significant decrease in RBF, creatinine clearance, and glutathione peroxidase compared to the control group. There was significant increase in Beclin-1 and LC3 mRNA gene expression in carvedilol, glibenclamide, and combined treatment groups as compared to IRI and control groups. Combination of carvedilol and glibenclamide significantly restored IRI changes when compared with the other pretreated groups. CONCLUSION: This study suggests that carvedilol and glibenclamide are promising reno-protective drugs to reduce renal injury induced by I/R through their antioxidant and autophagy stimulation.

The crucial role of oxidative stress in non-alcoholic fatty liver disease-induced male reproductive toxicity: the ameliorative effects of Iranian indigenous probiotics

Several studies have focused on the high potential effects of probiotics on the reproductive system. However, there is a paucity of information regarding the ameliorative intracellular roles of indigenous Iranian yogurt-extracted/cultured probiotics on animals' reproductive health suffering from obesity and/or fatty liver disease, such as non-alcoholic fatty liver disease (NAFLD). For this purpose, simultaneously with the consumption of D-fructose (200 g/1000 mL water, induction of NAFLD model), all pubertal animals were also gavaged every day for 63 consecutive days with extracted probiotics, including 1 × 109 CFU/mL of Lactobacillus acidophilus (LA), Bifidobacterium spp. (BIF), Bacillus coagulans (BC), Lactobacillus rhamnosus (LR), and a mixture form (LA + BIF + BC + LR). At the end of the ninth week, the indices of epididymal sperm, and oxidative stress, as well as histopathological changes, were assessed. The results show that NAFLD could induce robust oxidative stress, highlighted as considerable increments in ROS level, TBARS content, total oxidized protein levels, along with severe decrements in reduced glutathione reservoirs, total antioxidant capacity in the hepatic and testicular tissues, as well as testicular and hepatic histopathological alterations. Moreover, a significant decrease in the percentage of sperm progressive motility, sperm count, and membrane integrity along with an increment in the percentage of sperm abnormality was detected in NAFLD animals. The observed adverse effects were significantly reversed upon probiotics treatment, especially in the group challenged with a mixture of all probiotics. Taken together, these findings indicate that the indigenous yogurt-isolated/cultured probiotics had a high potential antioxidant activity and the ameliorative effect against reprotoxicity and blood biochemical alterations induced by the NAFLD model. Highlights: 1. Reproductive indices could be reversely affected by xenobiotics and diseases. 2. NAFLD and cholestasis considerably affect the reproductive system in both genders. 3. NAFLD induced hepatic and testicular oxidative stress (OS). 4. NAFLD induced histopathological alterations and spermatotoxicity through OS. 5. The adverse effects were significantly reversed upon exposure to probiotics.

Microstructure, morphology and physicochemical properties of nanocomposites containing hydroxyapatite/vivianite/graphene oxide for biomedical applications

Designing a nanocomposite that accumulates biocompatibility and antimicrobial behaviour is an essential requirement for biomedical applications. Hydroxyapatite (HAP), graphene oxide, and vivianite in one ternary nanocomposite with three phases and shapes led to an increase in cell viability to 97.6% ± 4 for the osteoblast cells in vitro. The obtained nanocomposites were investigated for their structural features using X-ray diffraction, while the microstructure features were analyzed using a scanning electron microscope (SEM) and a transmission electron microscope. The analysis showed a decrease in the crystal size to 13 nm, while the HAP grains reached 30 nm. The elongated shape of vivianite reached 200 nm on SEM micrographs. The monoclinic and hexagonal crystal systems of HAP and vivianite were presented in the ternary nanocomposite. The maximum roughness peak height reached 236.1 nm for the ternary nanocomposite from 203.3 nm, while the maximum height of the roughness parameter reached 440.7 nm for the di-nanocomposite of HAP/graphene oxide from 419.7 nm. The corrosion current density reached 0.004 μA/cm² . The ferrous (Fe²⁺ ) and calcium (Ca²⁺ ) ions released were measured and confirmed. Therefore, the morphology of the nanocomposites affected bacterial activity. This was estimated as an inhibition zone and reached 14.5 ± 0.9 and 13.4 ± 1.1 mm for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) after 24 h. The increase in viability and the antibacterial activity refer to the compatibility of the nanocomposite in different medical applications.

Salt stress improves thermotolerance and high-temperature bioethanol production of multi-stress-tolerant Pichia kudriavzevii by stimulating intracellular metabolism and inhibiting oxidative damage

BACKGROUND

High-temperature bioethanol production benefits from yeast thermotolerance. Salt stress could induce obvious cross-protection against heat stress of Pichia kudriavzevii, contributing to the improvement of its thermotolerance and bioethanol fermentation. However, the underlying mechanisms of the cross-protection remain poorly understood.

RESULTS

Salt stress showed obvious cross-protection for thermotolerance and high-temperature ethanol production of P. kudriavzevii observed by biomass, cell morphology and bioethanol production capacity. The biomass and ethanol production of P. kudriavzevii at 45 °C were, respectively, improved by 2.6 and 3.9 times by 300 mmol/L NaCl. Metabolic network map showed that salt stress obviously improved the key enzymes and intermediates in carbohydrate metabolism, contributing to the synthesis of bioethanol, ATP, amino acids, nucleotides, and unsaturated fatty acids, as well as subsequent intracellular metabolisms. The increasing trehalose, glycerol, HSPs, and ergosterol helped maintain the normal function of cell components. Heat stress induced serious oxidative stress that the ROS-positive cell rate and dead cell rate, respectively, rose from 0.5% and 2.4% to 28.2% and 69.2%, with the incubation temperature increasing from 30 to 45 °C. The heat-induced ROS outburst, oxidative damage, and cell death were obviously inhibited by salt stress, especially the dead cell rate which fell to only 20.3% at 300 mmol/L NaCl. The inhibiting oxidative damage mainly resulted from the abundant synthesis of GSH and GST, which, respectively, increased by 4.8 and 76.1 times after addition of 300 mmol/L NaCl. The improved bioethanol production was not only due to the improved thermotolerance, but resulted from the up-regulated alcohol dehydrogenases and down-regulated aldehyde dehydrogenases by salt stress.

CONCLUSION

The results provide a first insight into the mechanisms of the improved thermotolerance and high-temperature bioethanol production of P. kudriavzevii by salt stress, and provide important information to construct genetic engineering yeasts for high-temperature bioethanol production.

Overview of the Cellular Stress Responses Involved in Fatty Acid Overproduction in E. coli

Research on microbial fatty acid metabolism started in the late 1960s, and till date, various developments have aided in elucidating the fatty acid metabolism in great depth. Over the years, synthesis of microbial fatty acid has drawn industrial attention due to its diverse applications. However, fatty acid overproduction imparts various stresses on its metabolic pathways causing a bottleneck to further increase the fatty acid yields. Numerous strategies to increase fatty acid titres in Escherichia coli by pathway modulation have already been published, but the stress generated during fatty acid overproduction is relatively less studied. Stresses like pH, osmolarity and oxidative stress, not only lower fatty acid titres, but also alter the cell membrane composition, protein expression and membrane fluidity. This review discusses an overview of fatty acid synthesis pathway and presents a panoramic view of various stresses caused due to fatty acid overproduction in E. coli. It also addresses how certain stresses like high temperature and nitrogen limitation can boost fatty acid production. This review paper also highlights the interconnections that exist between these stresses.

Copper Tolerance Mechanism of the Novel Marine Multi-Stress Tolerant Yeast Meyerozyma guilliermondii GXDK6 as Revealed by Integrated Omics Analysis

Various agricultural products used in food fermentation are polluted by heavy metals, especially copper, which seriously endangers human health. Methods to remove copper with microbial strategies have gained interests. A novel Meyerozyma guilliermondii GXDK6 could survive independently under high stress of copper (1400 ppm). The copper tolerance mechanism of GXDK6 was revealed by integrated omics in this work. Whole-genome analysis showed that nine genes (i.e., CCC2, CTR3, FRE2, GGT, GST, CAT, SOD2, PXMP4, and HSP82) were related to GXDK6 copper tolerance. Copper stress elevated glutathione metabolism-related gene expression, glutathione content, and glutathione sulfur transferase activity, suggesting enhanced copper conjugation and detoxification in cells. The inhibited copper uptake by Ctr3 and enhanced copper efflux by Ccc2 contributed to the decrease in intracellular copper concentration. The improved expression of antioxidant enzyme genes (PXMP4, SOD2, and CAT), accompanied by the enhanced activities of antioxidant enzymes (peroxidase, superoxide dismutase, and catalase), decreased copper-induced reactive oxygen species production, protein carbonylation, lipid peroxidation, and cell death. The metabolite D-mannose against harsh stress conditions was beneficial to improving copper tolerance. This study contributed to understanding the copper tolerance mechanism of M. guilliermondii and its application in removing copper during fermentation.

L-amino acid oxidase from snake venom: Biotransformation and induction of apoptosis in human colon cancer cells

This study evaluated the potential of antitumor activity of snake venom from Vipera ammodytes and L-amino acid oxidase from Crotalus adamanteus on different colorectal cancer cell lines through determination of cytotoxic activity by MTT assay, pro-apoptotic activity by acridine orange/ethidium bromide staining, and concentrations of redox status parameters (superoxide, reduced glutathione, lipid peroxidation) by colorimetric methods. The expression of genes involved in the biotransformation process and metabolite efflux was determined by qPCR method, while protein expression of glutathione synthetase and P-glycoprotein were analysed by immunocytochemistry. The analysis of cell death shows that snake venom dominantly leads cells to necrosis. Induction of apoptosis by L-amino acid oxidase was in correlation with oxidative disbalance in cancer cells. Gene expression profile of membrane transporters and CYP genes were different in each cell line and in correlation with their sensitivity of treatment. Our results show that L-amino acid oxidase from snake venom is a potent cytotoxic substance with pronounced pro-apoptotic activity. The inhibition of P-glycoprotein suggests that L-amino acid oxidase is a good substance for furter research of antitumor effect, with unexpressed potential for occurrence of drug resistance in vitro.

Salicylic acid: A key regulator of redox signalling and plant immunity

In plants, the reactive oxygen species (ROS) formed during normal conditions are essential in regulating several processes, like stomatal physiology, pathogen immunity and developmental signaling. However, biotic and abiotic stresses can cause ROS over-accumulation leading to oxidative stress. Therefore, a suitable equilibrium is vital for redox homeostasis in plants, and there have been major advances in this research arena. Salicylic acid (SA) is known as a chief regulator of ROS; however, the underlying mechanisms remain largely unexplored. SA plays an important role in establishing the hypersensitive response (HR) and systemic acquired resistance (SAR). This is underpinned by a robust and complex network of SA with Non-Expressor of Pathogenesis Related protein-1 (NPR1), ROS, calcium ions (Ca²⁺), nitric oxide (NO) and mitogen-activated protein kinase (MAPK) cascades. In this review, we summarize the recent advances in the regulation of ROS and antioxidant defense system signalling by SA at the physiological and molecular levels. Understanding the molecular mechanisms of how SA controls redox homeostasis would provide a fundamental framework to develop approaches that will improve plant growth and fitness, in order to meet the increasing global demand for food and bioenergy.

Histochrome Attenuates Myocardial Ischemia-Reperfusion Injury by Inhibiting Ferroptosis-Induced Cardiomyocyte Death

Reactive oxygen species (ROS) and intracellular iron levels are critical modulators of lipid peroxidation that trigger iron-dependent non-apoptotic ferroptosis in myocardial ischemia-reperfusion (I/R) injury. Histochrome (HC), with a potent antioxidant moiety and iron-chelating capacity, is now available in clinical practice. However, limited data are available about the protective effects of HC on ferroptotic cell death in myocardial I/R injury. In this study, we investigated whether the intravenous administration of HC (1 mg/kg) prior to reperfusion could decrease myocardial damage by reducing ferroptosis. Rats undergoing 60 min of ischemia and reperfusion were randomly divided into three groups as follows: (1) Sham, (2) I/R control, and (3) I/R + HC. Serial echocardiography up to four weeks after I/R injury showed that intravenous injection of HC significantly improved cardiac function compared to the I/R controls. In addition, the hearts of rats who received intravenous injection of HC exhibited significantly lower cardiac fibrosis and higher capillary density. HC treatment decreased intracellular and mitochondrial ROS levels by upregulating the expression of nuclear factor erythroid 2-related factor (Nrf2) and its downstream genes. HC also inhibited erastin- and RSL3-induced ferroptosis in rat neonatal cardiomyocytes by maintaining the intracellular glutathione level and through upregulated activity of glutathione peroxidase 4. These findings suggest that early intervention with HC before reperfusion rescued myocardium from I/R injury by preventing ferroptotic cell death. Therefore, HC is a promising therapeutic option to provide secondary cardioprotection in patients who undergo coronary reperfusion therapy.

Inhibition of γH2AX, COX-2 and regulation of antioxidant enzymes in MPP+-exposed SH-SY5Y cells pre-treated with rutin

Many plant-derived bioactive compounds such as rutin are reportedly effective in attenuating neuronal death in most neurodegenerative disorders. Parkinson's disease (PD) is characterized by the gradual degeneration of dopaminergic neurons in the substantia nigra of the midbrain, and has previously been modelled in-vitro through the specific neurotoxic activity of 1-methyl-4-phenylpyridinium (MPP⁺) on dopaminergic neurons. Rutin is a bioflavonoid with multiple pharmacological effects, and this study investigated the neuroprotective effects of rutin in the human dopaminergic SH-SY5Y cell line using the neurotoxin MPP⁺. SH-SY5Y cells pretreated with rutin, were exposed to MPP⁺ and evaluated for cell viability, nitric oxide (NO), reactive oxygen species (ROS) and antioxidant enzymes activities. In addition, western blot techniques were used to determine the protein expression levels of γH2AX and COX-2. Rutin significantly attenuated MPP⁺-induced loss of cell viability, mitigated ROS and NO production and inhibited the disruption of antioxidant enzymes activity. It was also observed that rutin significantly reduced protein expression levels of γH2AX and COX-2 in SH-SY5Y cells treated with MPP⁺. Taken together, findings from this study tend to suggest that rutin is a promising neuroprotective compound for the treatment of PD through its effects on some of the mechanisms that characterize this neurodegenerative disease.

Impact of cisplatin administration on cerebellar cortical structure and locomotor activity of infantile and juvenile albino rats: the role of oxidative stress

The central neurotoxicity of cisplatin (CisPt) has always raised questions especially during development, but few studies are available. Hence, this work was designed to assess the CisPt's impacts on the postnatal rat cerebellum via evaluation of locomotor activity, histological and immunohistochemical studies, and to focus on cerebellar oxidative stress-related alterations. Eighty newborn pups were divided into 2 equal experimental groups: the control group was kept without any treatment and CisPt-treated group received a single subcutaneous injection of CisPt (5 μg /g b.w.) in their nape at PD10. Ten rats at PD11, PD17, and PD30 ages were weighed, then deeply anesthetized and sacrificed. For locomotor assessment, 20 pups were divided equally into control and CisPt-treated groups and tested at PD11-13, PD15-17, and PD28-30 ages. CisPt-treated rats suffered from decreased motor activity and showed decreased body and cerebellar weights, reduced levels of enzymatic antioxidants (SOD and CAT), and non-enzymatic antioxidant defense (GSH), and increase of lipid peroxidation marker (MDA). Histopathologically, CisPt sowed deleterious changes within cerebellar cortical layers in the form of vacuolations, decreased thickness, and hemorrhage (in PD17), while Purkinje cells exhibited profound degenerative changes in the form of swelling, disrupted arrangement, distortion, and nuclear shrinkage. In CisPt-treated rats, GFAP demonstrated upregulated, hypertrophied, and branched Bergmann glial fibers and reactive astrogliosis. Immuno-localization of Ki-67-positive cells revealed defective migration associated with decreased proliferation in early ages in addition to glial proliferation in PD30. In conclusion, CisPt causes oxidative stress-related deleterious effects on structure of developing cerebellar cortex and affects locomotor activity.

Does membrane curvature elastic energy play a role in mediating oxidative stress in lipid membranes?

The effects of oxidative stress on cells are associated with a wide range of pathologies. Oxidative stress is predominantly initiated by the action of reactive oxygen species and/or lipoxygenases on polyunsaturated fatty acid containing lipids. The downstream products are oxidised phospholipids, bioactive aldehydes and a range of Schiff base by-products between aldehydes and lipids, or other biomacromolecules. In this review we assess the impact of oxidative stress on lipid membranes, focusing on the changes that occur to the curvature preference (lipid spontaneous curvature) and elastic properties of membranes, since these biophysical properties modulate phospholipid homeostasis. Studies show that the lipid products of oxidative stress reduce stored curvature elastic energy in membranes. Based upon this observation, we hypothesize that the effects of oxidative stress on lipid membranes will be reduced by compounds that increase stored curvature elastic energy. We find a strong correlation appears across literature studies that we have reviewed, such that many compounds like vitamin E, Curcumin, Coenzyme Q10 and vitamin A show behaviour consistent with this hypothesis. Finally, we consider whether age-related changes in lipid composition represent the homeostatic response of cells to compensate for the accumulation of in vivo lipid oxidation products.

Dynamic posttranslational modifications of cytoskeletal proteins unveil hot spots under nitroxidative stress

The cytoskeleton is a supramolecular structure consisting of interacting protein networks that support cell dynamics in essential processes such as migration and division, as well as in responses to stress. Fast cytoskeletal remodeling is achieved with the participation of regulatory proteins and posttranslational modifications (PTMs). Redox-related PTMs are emerging as critical players in cytoskeletal regulation. Here we used a cellular model of mild nitroxidative stress in which a peroxynitrite donor induced transient changes in the organization of three key cytoskeletal proteins, i.e., vimentin, actin and tubulin. Nitroxidative stress-induced reconfiguration of intermediate filaments, microtubules and actin structures were further correlated with their PTM profiles and dynamics of the PTM landscape. Using high-resolution mass spectrometry, 62 different PTMs were identified and relatively quantified in vimentin, actin and tubulin, including 12 enzymatic, 13 oxidative and 2 nitric oxide-derived modifications as well as 35 modifications by carbonylated lipid peroxidation products, thus evidencing the occurrence of a chain reaction with formation of numerous reactive species and activation of multiple signaling pathways. Our results unveil the presence of certain modifications under basal conditions and their modulation in response to stress in a target-, residue- and reactive species-dependent manner. Thus, some modifications accumulated during the experiment whereas others varied transiently. Moreover, we identified protein PTM "hot spots", such as the single cysteine residue of vimentin, which was detected in seven modified forms, thus, supporting its role in PTM crosstalk and redox sensing. Finally, identification of novel PTMs in these proteins paves the way for unveiling new cytoskeleton regulatory mechanisms.

MicroRNA-137-3p Protects PC12 Cells Against Oxidative Stress by Downregulation of Calpain-2 and nNOS

The imbalance between excess reactive oxygen species (ROS) generation and insufficient antioxidant defenses contribute to a range of neurodegenerative diseases. High ROS levels damage cellular macromolecules such as DNA, proteins and lipids, leading to neuron vulnerability and eventual death. However, the underlying molecular mechanism of the ROS regulation is not fully elucidated. Recently, an increasing number of studies suggest that microRNAs (miRNAs) emerge as the targets in regulating oxidative stress. We recently reported the neuroprotective effect of miR-137-3p for brachial plexus avulsion-induced motoneuron death. The present study is sought to investigate whether miR-137-3p also could protect PC12 cells against hydrogen peroxide (H2O2) induced neurotoxicity. By using cell viability assay, ROS assay, gene and protein expression assay, we found that PC-12 cells exposed to H2O2 exhibited decreased cell viability, increased expression levels of calpain-2 and neuronal nitric oxide synthase (nNOS), whereas a decreased miR-137-3p expression. Importantly, restoring the miR-137-3p levels in H2O2 exposure robustly inhibited the elevated nNOS, calpain-2 and ROS expression levels, which subsequently improved the cell viability. Furthermore, the suppressive effect of miR-137-3p on the elevated ROS level under oxidative stress was considerably blunted when we mutated the binding site of calpain-2 targted by miR-137-3p, suggesting the critical role of calpain-2 involving the neuroprotective effect of miR-137-3p. Collectively, these findings highlight the neuroprotective role of miR-137-3p through down-regulating calpain and NOS activity, suggesting its potential role for combating oxidative stress insults in the neurodegenerative diseases.

Oxidative Stress in Non-Dialysis-Dependent Chronic Kidney Disease Patients

Background: Cardiovascular complications are the leading cause of morbidity and mortality at any stage of chronic kidney disease (CKD). Moreover, the high rate of cardiovascular mortality observed in these patients is associated with an accelerated atherosclerosis process that likely starts at the early stages of CKD. Thus, traditional and non-traditional or uremic-related factors represent a link between CKD and cardiovascular risk. Among non-conventional risk factors, particular focus has been placed on anaemia, mineral and bone disorders, inflammation, malnutrition and oxidative stress and, in this regard, connections have been reported between oxidative stress and cardiovascular disease in dialysis patients. Methods: We evaluated the oxidation process in different molecular lines (proteins, lipids and genetic material) in 155 non-dialysis patients at different stages of CKD and 45 healthy controls. To assess oxidative stress status, we analyzed oxidized glutathione (GSSG), reduced glutathione (GSH) and the oxidized/reduced glutathione ratio (GSSG/GSH) and other oxidation indicators, including malondialdehyde (MDA) and 8-oxo-2’-deoxyguanosine (8-oxo-dG). Results: An active grade of oxidative stress was found from the early stages of CKD onwards, which affected all of the molecular lines studied. We observed a heightened oxidative state (indicated by a higher level of oxidized molecules together with decreased levels of antioxidant molecules) as kidney function declined. Furthermore, oxidative stress-related alterations were significantly greater in CKD patients than in the control group. Conclusions: CKD patients exhibit significantly higher oxidative stress than healthy individuals, and these alterations intensify as eGFR declines, showing significant differences between CKD stages. Thus, future research is warranted to provide clearer results in this area.