Antioxidant enzymes as redox-based biomarkers: a brief review

Neurotoxicity of Some Environmental Pollutants to Zebrafish

The aquatic environment encompasses a wide variety of pollutants, from plastics to drug residues, pesticides, food compounds, and other food by-products, and improper disposal of waste is the main cause of the accumulation of toxic substances in water. Monitoring, assessing, and attempting to control the effects of contaminants in the aquatic environment are necessary and essential to protect the environment and thus human and animal health, and the study of aquatic ecotoxicology has become topical. In this respect, zebrafish are used as model organisms to study the bioaccumulation, toxicity, and influence of environmental pollutants due to their structural, functional, and material advantages. There are many similarities between the metabolism and physiological structures of zebrafish and humans, and the nervous system structure, blood-brain barrier function, and social behavior of zebrafish are characteristics that make them an ideal animal model for studying neurotoxicity. The aim of the study was to highlight the neurotoxicity of nanoplastics, microplastics, fipronil, deltamethrin, and rotenone and to highlight the main behavioral, histological, and oxidative status changes produced in zebrafish exposed to them.

Targeting Pathways and Integrated Approaches to Treat Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic symmetrical systemic disorder that not only affects joints but also other organs such as heart, lungs, kidney, and liver. Approximately there is 0.5%-1% of the total population affected by RA. RA pathogenesis still remains unclear due to which its appropriate treatment is a challenge. Further, multitudes of factors have been reported to affect its progression i.e. genetic factor, environmental factor, immune factor, and oxidative factor. Therapeutic approaches available for the treatment of RA include NSAIDs, DMARDs, enzymatic, hormonal, and gene therapies. But most of them provide the symptomatic relief without treating the core of the disease. This makes it obligatory to explore and reach the molecular targets for cure and long-term relief from RA. Herein, we attempt to provide extensive overlay of the new targets for RA treatment such as signaling pathways, proteins, and receptors affecting the progression of the disease and its severity. Precise modification in these targets such as suppressing the notch signaling pathway, SIRT 3 protein, Sphingosine-1-phosphate receptor and stimulating the neuronal signals particularly efferent vagus nerve and SIRT 1 protein may offer long term relief and potentially diminish the chronicity. To target or alter the novel molecules and signaling pathway a specific delivery system is required such as liposome, nanoparticles and micelles and many more. Present review paper discusses in detail about novel targets and delivery systems for treating RA.

Insights into the Structure-Capacity of Food Antioxidant Compounds Assessed Using Coulometry

CDAC (coulometrically determined antioxidant capacity) involves the determination of the antioxidant capacity of individual compounds or their mixtures using constant-current coulometry, with electrogenerated Br2 as the titrant, and biamperometric detection of the endpoint via Br2 excess. CDAC is an accurate, sensitive, rapid, and cheap measurement of the mol electrons (mol e-) transferred in a redox process. In this study, the CDAC of 48 individual antioxidants commonly found in foods has been determined. The molar ratio CDAC (CDACχ, mol e- mol-1) of representative antioxidants is ranked as follows: tannic acid > malvidin-3-O-glucoside ≃ curcumin > quercetin > catechin ≃ ellagic acid > gallic acid > tyrosol > BHT ≃ hydroxytyrosol > chlorogenic acid ≃ ascorbic acid ≃ Trolox®. In many cases, the CDACχ ranking of the flavonoids did not comply with the structural motifs that promote electron or hydrogen atom transfers, known as the Bors criteria. As an accurate esteem of the stoichiometric coefficients for reactions of antioxidants with Br2, the CDACχ provides insights into the structure-activity relationships underlying (electro)chemical reactions. The electrochemical ratio (ER), defined as the antioxidant capacity of individual compounds relative to ascorbic acid, represents a dimensionless nutritional index that can be used to estimate the antioxidant power of any foods on an additive basis.

Lycopene attenuates chlorpyrifos-induced hepatotoxicity in rats via activation of Nrf2/HO-1 axis

Chlorpyrifos (CPF), is an organophosphate pesticide that is widely used for agricultural purposes. However, it has well-documented hepatotoxicity. Lycopene (LCP) is a plant-derived carotenoid with antioxidant and anti-inflammatory activities. The present work was designed to evaluate the potential hepatoprotective actions of LCP against CPF-induced hepatotoxicity in rats. Animals were assigned into five groups namely: Group I (Control), Group II (LCP), Group III (CPF), Group IV (CPF + LCP 5 mg/kg), and Group V (CPF + LCP 10 mg/kg). LCP offered protection as evidenced by inhibiting the rise in serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) induced by CPF. This was confirmed histologically as LCP-treated animals showed liver tissues with less proliferation of bile ducts and periductal fibrosis. LCP significantly prevented the rise in hepatic content of malondialdehyde (MDA), depletion of reduced glutathione (GSH), and exhaustion of glutathione-s-transferase (GST) and superoxide dismutase (SOD). Further, LCP significantly prevented hepatocyte death as it ameliorated the increase in Bax and the decrease in Bcl-2 expression induced by CPF in liver tissues as determined immunohistochemically. The observed protective effects of LCP were further confirmed by a significant enhancement in heme oxygenase-1 (HO-1) and NF-E2-related factor 2 (Nrf2) expression. In conclusion, LCP possesses protective effects against CPF-induced hepatotoxicity. These include antioxidation and activation of the Nrf2/HO-1 axis.

A non-specific lipid transfer protein, NtLTPI.38, positively mediates heat tolerance by regulating photosynthetic ability and antioxidant capacity in tobacco

Non-specific lipid transfer proteins (nsLTPs) play an important role in plant growth and stress resistance; however, their function in tobacco remains poorly understood. Therefore, to explore the function of NtLTP in response to high temperature, we identified an NtLTPI.38 from tobacco, obtained its overexpression and knockout transgenic plants, and further studied their response to heat stress (42 °C). The results showed that NtLTPI.38 overexpression in tobacco reduced chlorophyll degradation, alleviated the high temperature damage to photosynthetic organs, and enhanced the photosynthetic capacity of tobacco under heat stress. NtLTPI.38 overexpression in heat-stressed tobacco increased the contents of soluble sugar and protein, proline, and flavonoid substances, reduced the relative conductivity, and decreased H₂O₂, O₂^•-, and MDA accumulation, and increased the enzymatic antioxidant activities, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), compared to wild type (WT) and knockout mutant plants. RT-PCR confirmed that the expression levels of antioxidant enzymes and thermal stress-related genes were significantly upregulated under thermal stress in overexpression plants. Therefore, NtLTPI.38 enhanced heat tolerance in tobacco by mitigating photosynthetic damage and improving osmoregulation and antioxidant capacity. These results provided the theoretical basis and a potential resource for further breeding projects to improve heat tolerance in plants.

Behavioral, biochemical, and endocrine responses of zebrafish to 30-min exposure with environmentally relevant concentrations of imidacloprid-based insecticide

The imidacloprid-based insecticides (IBIs) are among the most used insecticides worldwide, and chronic and acute toxic effects (days exposure protocols) have been reported in several species in studies of IBIs at lethal concentrations. However, there is little information on shorter time exposures and environmentally relevant concentrations. In this study, we investigated the effect of a 30-min exposure to environmentally relevant concentrations of IBI on the behavior, redox status, and cortisol levels of zebrafish. We showed that the IBI decreased fish locomotion and social and aggressive behaviors and induced an anxiolytic-like behavior. Furthermore, IBI increased cortisol levels and protein carbonylation and decreased nitric oxide levels. These changes were mostly observed at 0.013 and 0.0013 µg·L^-1 of IBI. In an environmental context, these behavioral and physiological disbalances, which were immediately triggered by IBI, can impair the ability of fish to evade predators and, consequently, affect their survival.

Arsenic Trioxide Triggers Mitochondrial Dysfunction, Oxidative Stress, and Apoptosis via Nrf 2/Caspase 3 Signaling Pathway in Heart of Ducks

Arsenic is a common environmental pollutant and poses a serious threat to human and animal health. In this study, we used the ducks to mimic arsenic trioxide (ATO) exposure and investigated the mechanism of cardiac toxicity. The results indicated that ATO inhibited the body and organ growth of ducks, led to an increase in LDH content, and caused obvious deformity, ischemia infarction. It is found that ATO exacerbated the swell of mitochondrial and the contraction of cell nuclei in the heart of ducks through transmission electron microscopy (TEM). ATO also induced an increase in MDA content; inhibited the activation of the Nrf 2 pathway; downregulated the expression of mRNA and protein of Nrf 2, HO-1, and SOD-1; and upregulated the expression of mRNA and protein of Keap 1. At the same time, ATO induced apoptosis which not only upregulated the expression levels of mRNA and proteins (Caspase 3, Cyt-C, P53, Bax) but also decreased the mRNA and protein expression level of Bcl-2. These results indicated that ATO can lead to oxidative stress and apoptosis in the heart of ducks. In general, our research shows that ATO triggers mitochondrial dysfunction, oxidative stress, and apoptosis via Nrf 2/Caspase 3 signaling pathway in the heart of ducks.

Antioxidant Activity and Phytopathogenic Control of Extracts and Fraction from Struthanthus calophyllus A.C.Sm. (Loranthaceae)

Phytopathogenic microorganisms cause oxidative stress in host plants, thus affecting agricultural crops. Such stress could be controlled by antioxidant compounds from parasitic plants, given their antioxidant power. This article reports an evaluation of Struthanthus calophyllus antimicrobial activity and antioxidant mechanism by testing different polarity extracts. Antimicrobial activity was evaluated against phytopathogens bacteria (e. g., Erwinia, Pectobacterium, Xanthomonas) using the agar diffusion method. Pectobacterium and Xanthomonas presented growth inhibition zones similar to streptomycin control. Antioxidant activity was determined by measuring total phenol content, DPPH⋅, and ABTS⋅+ radicals-scavenging inhibition percentage (IP). Most polar extracts presented 76,9-95,9 % IP, which correlates with its phenolic content. Besides, Nuclear Magnetic Resonance in a V14-1 sub-fraction from stem ethanolic extract, chose one for highest yield percentage, highest metabolites presence, and antimicrobial activity, showed triterpenic compounds mixture (α-amyrin, β-amyrin and 24-methylenecycloartanol). Findings in this study are among the first reports for S. calophyllus, even the chemical characterization, that confirm its strong antioxidant and antibacterial activities. Further molecular composition research about parasitic plants could show how unknown compounds may combat pathogenic microorganisms.

Phytochemical Analysis and Anti-Inflammatory Potential of Acanthus mollis L. Rhizome Hexane Extract

The rhizomes of Acanthus mollis have traditionally been used for the treatment of several ailments involving inflammation. However, to the best of our knowledge, their chemical composition and pharmacological properties have not been studied until now. As a first approach, this study analyses the A. mollis rhizome hexane extract phytochemistry and its anti-inflammatory and antioxidant capacities in HepG2 and RAW 264.7 cell culture assays. Chemical profiling was performed with gas chromatography mass spectrometry without the modification of native molecules. Free phytosterols (such as β-sitosterol) account for 70% of detected compounds. The anti-inflammatory capacity of the rhizome extract of A. mollis is mediated by the decrease in the NO production in RAW 264.7 that has previously been stimulated with lipopolysaccharide in a dose-dependent manner. Furthermore, HepG2 pre-treatment with the rhizome extract prevents any damage being caused by oxidative stress, both through ROS scavenge and through the antioxidant cellular enzyme system. In this respect, the extract reduced the activity of glutathione peroxidase and reductase, which were stimulated under oxidative stress conditions. Our results suggest that the extract from the rhizomes of A. mollis may constitute a potential source of natural products with anti-inflammatory activity and could validate the traditional use of A. mollis.

Antioxidant enzyme and DNA base repair genetic risk scores' associations with systemic oxidative stress biomarker in pooled cross-sectional studies

Background: Oxidative stress is hypothesized to contribute to the pathogenesis of several chronic diseases. Numerous dietary and lifestyle factors are associated with oxidative stress; however, little is known about associations of genetic factors, individually or jointly with dietary and lifestyle factors, with oxidative stress in humans. Methods: We genotyped 22 haplotype-tagging single nucleotide polymorphisms (SNPs) in 3 antioxidant enzyme (AE) genes and 79 SNPs in 14 DNA base excision repair (BER) genes to develop oxidative stress-specific AE and BER genetic risk scores (GRS) in two pooled cross-sectional studies (n = 245) of 30-74-year-old, White, cancer- and inflammatory bowel disease-free adults. Of the genotypes, based on their associations with a systemic oxidative stress biomarker, plasma F₂-isoprostanes (FiP) concentrations, we selected 4 GSTP1 SNPs for an AE GRS, and 12 SNPs of 5 genes (XRCC1, TDG, PNKP, MUTYH, and FEN1) for a BER GRS. We also calculated a previously-reported, validated, questionnaire-based, oxidative stress biomarker-weighted oxidative balance score (OBS) comprising 17 anti- and pro-oxidant dietary and lifestyle exposures, with higher scores representing a higher predominance of antioxidant exposures. We used general linear regression to assess adjusted mean FiP concentrations across GRS and OBS tertiles, separately and jointly. Results: The adjusted mean FiP concentrations among those in the highest relative to the lowest oxidative stress-specific AE and BER GRS tertiles were, proportionately, 11.8% (p = 0.12) and 21.2% (p = 0.002) higher, respectively. In the joint AE/BER GRS analysis, the highest estimated mean FiP concentration was among those with jointly high AE/BER GRS. Mean FiP concentrations across OBS tertiles were similar across AE and BER GRS strata. Conclusion: Our pilot study findings suggest that DNA BER, and possibly AE, genotypes collectively may be associated with systemic oxidative stress in humans, and support further research in larger, general populations.

Bisphenol AF induces multiple behavioral and biochemical changes in zebrafish (Danio rerio) at different life stages

As common environmental endocrine-disrupting chemicals (EDCs), bisphenol AF (BPAF) raises potential concerns for aquatic organisms due to its widespread presence and continued release in the aquatic environment. This research aimed to use zebrafish embryos and adult fish to explore the effects of environmentally relevant concentrations (5 μg/L), 50 μg/L and 500 μg/L of BPAF on zebrafish embryonic development, behavioral alterations, and the potential mechanisms driving these effects. The results showed that 500 μg/L of BPAF severely affected the growth and development of embryos. In behavioral experiments, all concentrations of BPAF significantly inhibited the locomotor activity of larvae, 50 and 500 μg/L BPAF significantly altered the anxiety-like and aggressive behavior of adult zebrafish. Furthermore, environmentally relevant concentrations and higher concentrations of BPAF induced varying degrees of oxidative stress in both embryonic and adult fish. The most significant histopathological changes and decreased acetylcholinesterase (AChE) activity were observed in the brain at 50 and 500 μg/L of BPAF. We hypothesized that oxidative stress is an important cause of behavioral disturbances in larvae and adult fish. To our best knowledge, the present experiment is a pioneer in studying the effects of BPAF on a variety of complex behaviors (swimming performance, anxiety-like, social behavior, aggression) in zebrafish, which emphasizes the potential health risk of higher concentrations of BPAF in terms of induced neurotoxicity.

Euryale ferox, a prominent superfood: Nutritional, pharmaceutical, and its economical importance

Euryale ferox (also known as foxnut), belongs to the family Nymphaeaceae. It is mainly grown in India, China, Japan, and Korea. It is a highly nutritious food, abundant in nutritional and bioactive compounds such as carbohydrates, protein, fiber, vitamins, minerals, and polyphenols. It is considered a functional food owing to its various health benefits such as antidiabetic, antihyperlipidemic, antifatigue, hepatoprotective, cardioprotective, antimelanogenic, etc. E. ferox has immense potential in both food and non-food industries. Regardless of being recognized as a superfood packed with nutritional as well as medicinal properties, it is still neglected, and there has not been much attention given to its cultivation. Therefore, in this review, the potential of E. ferox as a superfood has been explored to enhance its utilization in the development of different foods and make it available outside its growing area. PRACTICAL APPLICATIONS: Euryale ferox is abundant in several macronutrients and micronutrients; and considered as a superfood in terms of various health benefits. E. ferox has the ability to be used in the development of different health, functional, and nutraceutical foods, which will open a new door for the food industry to combat with numerous diseases.

Evaluation of Toxic Effects Induced by Sub-Acute Exposure to Low Doses of α-Cypermethrin in Adult Male Rats

To contribute new information to the pyrethroid pesticide α-cypermethrin toxicity profile, we evaluated its effects after oral administration to Wistar rats at daily doses of 2.186, 0.015, 0.157, and 0.786 mg/kg bw for 28 days. Evaluations were performed using markers of oxidative stress, cholinesterase (ChE) activities, and levels of primary DNA damage in plasma/whole blood and liver, kidney, and brain tissue. Consecutive exposure to α-cypermethrin affected the kidney, liver, and brain weight of rats. A significant increase in concentration of the thiobarbituric acid reactive species was observed in the brain, accompanied by a significant increase in glutathione peroxidase (GPx) activity. An increase in GPx activity was also observed in the liver of all α-cypermethrin-treated groups, while GPx activity in the blood was significantly lower than in controls. A decrease in ChE activities was observed in the kidney and liver. Treatment with α-cypermethrin induced DNA damage in the studied cell types at almost all of the applied doses, indicating the highest susceptibility in the brain. The present study showed that, even at very low doses, exposure to α-cypermethrin exerts genotoxic effects and sets in motion the antioxidative mechanisms of cell defense, indicating the potential hazards posed by this insecticide.

Do Circulating Redox Biomarkers Have Diagnostic Significance in Alcohol-Intoxicated People?

The toxic properties of ethanol are inextricably linked to oxidative stress. Despite many reports on the effects of alcohol dependence on blood redox homeostasis, there are no data on the oxidative stress profile in alcohol-poisoned cases. There are also no data on the diagnostic usefulness of redox biomarkers determined post-mortem in various biological fluids. This work investigates the utility of enzymatic and non-enzymatic antioxidant barrier, redox status, and oxidative/nitrosative stress biomarkers in different biological fluids (such as blood, urine, vitreous humor, and cerebrospinal fluid) in the post-mortem study of patients with acute alcohol intoxication. The study group included those who died due to acute ethanol intoxication (n = 22). The research showed a significant increase in glutathione peroxidase activity, total antioxidant status, ferric reducing antioxidant power, and tryptophan concentration only in the study group’s urine compared to the control. In other circulating fluids, both antioxidant enzyme activities and glycoxidation product concentrations were not significantly different in individuals who died of alcohol overdose compared with those who died suddenly. We also did not observe a connection between oxidation–reduction balance and the amount of alcohol consumed before death. These unexpected observations may be caused by irreversible post-mortem changes occurring at the cellular level due to autolysis and putrefaction. In summary, the use of circulating body fluids to assess redox homeostasis is limited in the post-mortem analysis. Our results indicate the increased stability of urine collected post mortem compared to other circulating bioliquids. Further studies are needed to assess the intensity of oxidative and carbonyl stress in ethanol-damaged organs and the effects of post-mortem processes on cellular redox balance.

Redox Interactions in Chemo/Radiation Therapy-induced Lung Toxicity; Mechanisms and Therapy Perspectives

Lung toxicity is a key limiting factor for cancer therapy, especially lung, breast, and esophageal malignancies. Radiotherapy for chest and breast malignancies can cause lung injury. However, systemic cancer therapy with chemotherapy may also induce lung pneumonitis and fibrosis. Radiotherapy produces reactive oxygen species (ROS) directly via interacting with water molecules within cells. However, radiation and other therapy modalities may induce the endogenous generation of ROS and nitric oxide (NO) by immune cells and some nonimmune cells such as fibroblasts and endothelial cells. There are several ROS generating enzymes within lung tissue. NADPH Oxidase enzymes, cyclooxygenase-2 (COX-2), dual oxidases (DUOX1 and DUOX2), and the cellular respiratory system in the mitochondria are the main sources of ROS production following exposure of the lung to anticancer agents. Furthermore, inducible nitric oxide synthase (iNOS) has a key role in the generation of NO following radiotherapy or chemotherapy. Continuous generation of ROS and NO by endothelial cells, fibroblasts, macrophages, and lymphocytes causes apoptosis, necrosis, and senescence, which lead to the release of inflammatory and pro-fibrosis cytokines. This review discusses the cellular and molecular mechanisms of redox-induced lung injury following cancer therapy and proposes some targets and perspectives to alleviate lung toxicity.

Potentiation of paraquat toxicity by inhibition of the antioxidant defenses and protective effect of the natural antioxidant, 4-hydroxyisopthalic acid in Drosophila melanogaster

Exposure to pesticides such as paraquat (PQ) is known to induce oxidative stress-mediated damage, which is implicated in neurodegenerative diseases. The antioxidant enzymes are part of the endogenous defense mechanisms capable of protecting against oxidative damage, and down-regulation of these enzymes results in elevated oxidative stress. In this study, we have evaluated the protective action of 4-hydroxyisophthalic acid (DHA-I), a novel bioactive molecule from the roots of D. hamiltonii, against PQ toxicity and demonstrated the protective role of endogenous antioxidant enzymes under the condition of oxidative stress using Drosophila model. The activity of the major antioxidant enzymes, superoxide dismutase 1 (SOD1) and catalase, was suppressed either by RNAi-mediated post transcriptional gene silencing or chemical inhibition. With the decreased in vivo activity of either SOD1 or catalase, Drosophila exhibited hypersensitivity to PQ toxicity, demonstrating the essential role of antioxidant enzymes in the mechanism of defense against PQ-induced oxidative stress. Dietary supplementation of DHA-I increased the resistance of Drosophila depleted in either SOD1 or catalase to PQ toxicity. Enhanced survival of flies against PQ toxicity indicates the protective role of DHA-I against oxidative stress-mediated damage under the condition of compromised antioxidant defenses.

Oxidative Stress in Tauopathies: From Cause to Therapy

Oxidative stress (OS) is the result of an imbalance between the production of reactive oxygen species (ROS) and the antioxidant capacity of cells. Due to its high oxygen demand, the human brain is highly susceptible to OS and, thus, it is not a surprise that OS has emerged as an essential component of the pathophysiology of several neurodegenerative diseases, including tauopathies. Tauopathies are a heterogeneous group of age-related neurodegenerative disorders characterized by the deposition of abnormal tau protein in the affected neurons. With the worldwide population aging, the prevalence of tauopathies is increasing, but effective therapies have not yet been developed. Since OS seems to play a key role in tauopathies, it has been proposed that the use of antioxidants might be beneficial for tau-related neurodegenerative diseases. Although antioxidant therapies looked promising in preclinical studies performed in cellular and animal models, the antioxidant clinical trials performed in tauopathy patients have been disappointing. To develop effective antioxidant therapies, the molecular mechanisms underlying OS in tauopathies should be completely understood. Here, we review the link between OS and tauopathies, emphasizing the causes of OS in these diseases and the role of OS in tau pathogenesis. We also summarize the antioxidant therapies proposed as a potential treatment for tauopathies and discuss why they have not been completely translated to clinical trials. This review aims to provide an integrated perspective of the role of OS and antioxidant therapies in tauopathies. In doing so, we hope to enable a more comprehensive understanding of OS in tauopathies that will positively impact future studies.

Lignans from Eucommia ulmoides Oliver leaves exhibit neuroprotective effects via activation of the PI3K/Akt/GSK-3β/Nrf2 signaling pathways in H2O2-treated PC-12 cells

BACKGROUND

Neuronal apoptosis and oxidative stress have the most crucial influence on neurodegenerative diseases, including Parkinson's disease. Rat adrenal pheochromocytoma cells (PC-12) induced by H₂O₂ are one of the primary in vitro models of Parkinson's disease (PD) . Previous studies have found that E ulmoides leaf extract exerts good neuroprotective activity and has the potential to treat neurodegenerative diseases. However, the molecular pathways involved in the neuroprotective effects of its primary leaf component, lignans, have not yet been well elucidated yet.

PURPOSE

This study aimed to evaluate the neuroprotective effects of lignans in E. ulmoides leaves and to explore the underlying mechanism.

METHODS

Cell viability was measured using the CCK-8 assay. Apoptosis was assessed by calcein/PI staining. The release levels of ROS and LDH were assessed using a commercial assay kit. The enzyme activities of SOD and GPx were measured using kits. The establishment of the compound-target-pathway-disease network was performed using a database and computer software. Antioxidant proteins (HO-1, NQO-1, and Cat) and related regulatory proteins (Nrf2, GSK-3β, p-GSK 3β (Ser 9), Akt, p-Akt (Tyr326), PI3K) were detected by western blotting. Apoptosis in the zebrafish head was assessed using acridine orange (AO) staining.

RESULTS

In the present study, 12 lignans were isolated and characterized from E. ulmoides leaves, including a new compound, (-)-7‑epi-pinoresinol mr1 (1). Compounds 1-12 exerted neuroprotective effects in H₂O₂-treated PC-12 cells by increasing cell viability, improving the enzyme activity of SOD and GPx, and reducing levels of ROS and LDH. Compared to the positive control group (25 μM hesperetin), cell viability in response to 25 μM compound 1 (78.0 ± 0.8%) was highest, but its relative percent LDH release (20.1 ± 2.5%) was the lowest; 25 μM compound 4 resulted in the lowest ROS release levels (101.7 ± 2.6%) and highest SOD enzyme activity (35.9 ± 4.2 U/mg), and the GPx enzyme activity of 25 μM compound 1 was strongest (197.6 ± 0.6 U/mg). Next, the potential targets (PI3K, GSK-3β) of the test compounds' antioxidant activity were identified using pharmacological network analysis. Using DAVID software for pharmacological network analysis, potential targets (PI3K, GSK-3β, and SOD2) of 12 lignans were identified. Based on the initial screening results, biological experiments confirmed that diepoxylignans 1, 2, and 4 exerted significant neuroprotection by regulating the PI3K/AKT/GSK-3β/Nrf2 signaling pathways, increasing protein expression of HO-1, NQO-1, and CAT, and enhancing the antioxidant enzyme activity of SOD and GPx.

CONCLUSION

Our experiments first propose that the diepoxylignans from E. ulmoides leaves exert neuroprotective effects via activation of the PI3K/Akt/GSK-3β/Nrf2 signaling pathway. These findings further indicate that lignans could be the primary components of E. ulmoides Oliver as agents for the prevention and treatment of neurodegenerative diseases. Collectively, Eucommia ulmoides leaves with important research value may be a potential candidate for traditional Chinese medicine for treating oxidative stress-related neurodegenerative diseases.

Transcriptomic and targeted metabolomic analysis revealed the toxic effects of prochloraz on larval zebrafish

Prochloraz (PCZ), an imidazole fungicide, has been extensively used in horticulture and agriculture to protect against pests and diseases. To investigate the potential toxicity of PCZ on aquatic organisms, larval zebrafish, as a model, were exposed to a series of concentrations (0, 20, 100, and 500 μg/L) of PCZ for 7 days. With transcriptomic analysis, we found that exposure to high dose PCZ could produce 76 downregulated and 345 upregulated differential expression genes (DEGs). Bioinformatics analysis revealed that most of the DEGs were characterized in the pathways of glycolipid metabolism, amino acid metabolism and oxidative stress in larval zebrafish. Targeted metabolomic analysis was conducted to verify the effects of PCZ on the levels of acyl-carnitines and some amino acids in larval zebrafish. In addition, biochemical indicators related to glycolipid metabolism were affected obviously, manifested as elevated triglyceride (TG) levels and decreased glucose (Glu) levels in whole larvae. The expression levels of genes associated with glycolipid metabolism were affected in larvae after exposure to PCZ (PK, GK, PEPckc, SREBP, ACO). Interestingly, we further confirmed that PCZ could induce oxidative stress by the changing enzyme activities (T-GSH, GSSG) and upregulating several related genes levels in larval zebrafish. Generally, our results revealed that the endpoints related to glycolipid metabolism, amino acid metabolism and oxidative stress were influenced by PCZ in larval zebrafish.

Associations of DNA Base Excision Repair and Antioxidant Enzyme Genetic Risk Scores with Biomarker of Systemic Inflammation

Background: Inflammation is implicated in the etiology of various aging-related diseases. Numerous dietary and lifestyle factors contribute to chronic systemic inflammation; genetic variation may too. However, despite biological plausibility, little is known about associations of antioxidant enzyme (AE) and DNA base excision repair (BER) genotypes with human systemic inflammation. Methods: We genotyped 22 single nucleotide polymorphisms (SNPs) in 3 AE genes, and 79 SNPs in 14 BER genes to develop inflammation-specific AE and BER genetic risk scores (GRS) in two pooled cross-sectional studies (n = 333) of 30-74-year-old White adults without inflammatory bowel disease, familial adenomatous polyposis, or a history of cancer or colorectal adenoma. Of the genotypes, based on their associations with a biomarker of systemic inflammation, circulating high sensitivity C-reactive protein (hsCRP) concentrations, we selected 2 SNPs of 2 genes (CAT and MnSoD) for an AE GRS, and 7 SNPs of 5 genes (MUTYH, SMUG1, TDG, UNG, and XRCC1) for a BER GRS. A higher GRS indicates a higher balance of variant alleles directly associated with hsCRP relative to variant alleles inversely associated with hsCRP. We also calculated previously-reported, validated, questionnaire-based dietary (DIS) and lifestyle (LIS) inflammation scores. We used multivariable general linear regression to compare mean hsCRP concentrations across AE and BER GRS categories, individually and jointly with the DIS and LIS. Results: The mean hsCRP concentrations among those in the highest relative to the lowest AE and BER GRS categories were, proportionately, 13.9% (p = 0.30) and 57.4% (p = 0.009) higher. Neither GRS clearly appeared to modify the associations of the DIS or LIS with hsCRP. Conclusion: Our findings suggest that genotypes of DNA BER genes collectively may be associated with systemic inflammation in humans.

Ozone pollution, oxidative stress, synaptic plasticity, and neurodegeneration

INTRODUCTION

Overpopulation and industrial growth result in an increase in air pollution, mainly due to suspended particulate matter and the formation of ozone. Repeated exposure to low doses of ozone, such as on a day with high air pollution levels, results in a state of chronic oxidative stress, causing the loss of dendritic spines, alterations in cerebral plasticity and in learning and memory mechanisms, and neuronal death and a loss of brain repair capacity. This has a direct impact on human health, increasing the incidence of chronic and degenerative diseases.

DEVELOPMENT

We performed a search of the PubMed, Scopus, and Google Scholar databases for original articles and reviews published between 2000 and 2018 and addressing the main consequences of ozone exposure on synaptic plasticity, information processing in cognitive processes, and the alterations that may lead to the development of neurodegenerative diseases.

CONCLUSIONS

This review describes one of the pathophysiological mechanisms of the effect of repeated exposure to low doses of ozone, which causes loss of synaptic plasticity by producing a state of chronic oxidative stress. This brain function is key to both information processing and the generation of structural changes in neuronal populations. We also address the effect of chronic ozone exposure on brain tissue and the close relationship between ozone pollution and the appearance and progression of neurodegenerative diseases.

Mechanisms and Clinical Implications of Endothelial Dysfunction in Arterial Hypertension

The endothelium is composed of a monolayer of endothelial cells, lining the interior surface of blood and lymphatic vessels. Endothelial cells display important homeostatic functions, since they are able to respond to humoral and hemodynamic stimuli. Thus, endothelial dysfunction has been proposed as a key and early pathogenic mechanism in many clinical conditions. Given the relevant repercussions on cardiovascular risk, the complex interplay between endothelial dysfunction and systemic arterial hypertension has been a matter of study in recent years. Numerous articles have been published on this issue, all of which contribute to providing an interesting insight into the molecular mechanisms of endothelial dysfunction in arterial hypertension and its role as a biomarker of inflammation, oxidative stress, and vascular disease. The prognostic and therapeutic implications of endothelial dysfunction have also been analyzed in this clinical setting, with interesting new findings and potential applications in clinical practice and future research. The aim of this review is to summarize the pathophysiology of the relationship between endothelial dysfunction and systemic arterial hypertension, with a focus on the personalized pharmacological and rehabilitation strategies targeting endothelial dysfunction while treating hypertension and cardiovascular comorbidities.

Zingerone attenuates zearalenone-induced steroidogenesis impairment and apoptosis in TM3 Leydig cell line

Zingerone¹ (Zing) is one of the bioactive compounds of ginger rhizome (Zingiber officinale), whose beneficial effects have been reported previously on reproductive organ complications. The current study purposed to survey probable protective impacts of Zing against Zearalenone (ZEA)-induced changes in the TM3 Leydig cell line. Exposure of TM3 cells to ZEA (25 μM) attenuates the levels of testosterone and steroidogenesis-related genes, which was reversed by 25 μM of Zing. ZEA also induced ROS generation and apoptosis in TM3 cells. Zing treatment improved the stress oxidative and apoptosis-related changes induced by ZEA in TM3 cells by modulating autophagy-related proteins and activating PI3K-AKT-mTOR and Nrf2 pathways. The findings of this study represented a theoretical basis for Zing's protective actions against ZEA toxic effects on TM3 cells.

Mediterranean Diet: A Tool to Break the Relationship of Atrial Fibrillation with the Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease

Atrial fibrillation (AF) is the most common supraventricular arrhythmia associated with increased cardiovascular and non-cardiovascular morbidity and mortality. As multiple factors may predispose the onset of AF, the prevention of the occurrence, recurrence and complications of this arrhythmia is still challenging. In particular, a high prevalence of cardio-metabolic comorbidities such as the metabolic syndrome (MetS) and in its hepatic manifestation, the non-alcoholic fatty liver disease (NAFLD), have been described in the AF population. A common pathogenetic mechanism linking AF, MetS and NAFLD is represented by oxidative stress. For this reason, in the past decades, numerous studies have investigated the effect of different foods/nutrients with antioxidant properties for the prevention of, and their therapeutic role is still unclear. In this narrative comprehensive review, we will summarize current evidence on (1) the association between AF, MetS and NAFLD (2) the antioxidant role of Mediterranean Diet and its components for the prevention of AF and (3) the effects of Mediterranean Diet on MetS components and NAFLD.

Catechin from green tea had the potential to decrease the chlorpyrifos induced oxidative stress in larval zebrafish (Danio rerio)

Catechin is a biological compound in green tea (Camellia sinesis), which has anti-oxidant, anti-cancer, anti-apoptotic, anti-inflammatory, and attenuated effects in different experimental models. Chlorpyrifos (CPF), a broad-spectrum organophosphate insecticide, has resulted in oxidative stress, mitochondrial dysfunction, and apoptosis in zebrafish. The goal of this study is to assess whether catechin can alleviate CPF-induced oxidative damage and apoptosis in the early developmental stage of zebrafish. According to the results, we observed that 200 μg/L CPF exposure could induce oxidative stress, ROS production and changing the antioxidant-related enzymes and genes in larval zebrafish. Interestingly, catechin had the potential to reduce the oxidative damage and cell apoptosis caused by CPF exposure in larval zebrafish at different endpoints. Especially, catechin could promote the contents of GSH and activity of GST in zebrafish larvae injured by CPF, suggesting that catechin could repair oxidative damage at a certain degree by regulating the activities and gene transcription of some key enzymes related to GSH pathway in zebrafish. In addition, at transcriptional levels, a high concentration of catechin exposure reduced the expression genes of Mn-SOD, Cat, gst, and GPX induced by CPF in larval zebrafish. These genes mainly reflected the degree of oxidative damage of zebrafish, which was basically consistent with the enzyme activity. Catechin also could reduce the transcription of p53 and bax, which are tightly related to the apoptosis induced by CPF in zebrafish larvae. The expression of genes was consistent with ROS production, which proved that catechin could alleviate the apoptosis induced by CPF. This study discovered that catechin had some antioxidant effects in aquatic animals to reduce the toxicity caused by pesticides and offered the scientific basis for the utilization and development of catechin.

Evaluation of the hepatoprotective effect of curcumin-loaded solid lipid nanoparticles against paracetamol overdose toxicity: Role of inducible nitric oxide synthase

Curcumin (Cur) is a natural compound that exhibited therapeutic effects against various liver injuries however Cur showed poor water solubility and bioavailability. This study aimed to design Cur-loaded solid lipid nanoparticles (SLNs) and to evaluate the hepatoprotective and antioxidant effects in a model of acute hepatotoxicity induced by paracetamol (PCM) overdose compared to the raw Cur and N-acetylcysteine (NAC). SLNs were prepared by emulsion/solvent evaporation method and 3² factorial design was employed. Wistar rats were divided into Control, PCM, PCM + NAC, PCM + raw Cur, and PCM + Cur-SLNs groups and treated orally for 14 days before receiving a single PCM dose. The Cur-loaded SLNs showed high entrapment efficiency % ranging between 69.1 and 92.1%, particle size (PS) between 217 and 506 nm, and zeta potential values between -17.9 and -25.5 mV. The in vivo results revealed that the PCM group exhibited deterioration of liver functions, pathological lesions on the liver tissues, severe oxidative stress, and increases in both the serum and hepatic iNOS levels. Remarkably, the PCM + Cur-SLNs group showed significantly better liver functions and tissue integrity compared to the PCM group. Furthermore, higher reduced glutathione and catalase but lower malondialdehyde and iNOS levels were observed. In conclusion, Cur-loaded SLNs effectively prevented the liver damage induced by PCM overdose through alleviating the oxidative stress and inhibiting the serum and hepatic iNOS expression in an effect comparable to NAC and better than raw Cur.

In vivo neurotoxic effects of emamectin benzoate in male mice: evaluation with enzymatic and biomolecular multi-biomarkers

The study of the toxic effects of emamectin benzoate (EMB) was conducted in male mice. Mice were randomly divided into 4 groups; control group, EMB25 group (1/30 LD₅₀ = 25 mg/kg/day), EMB50 group (1/15 LD₅₀ = 50 mg/kg/day), and EMB100 group (1/7.5 LD₅₀ = 100 mg/kg/day). Control group received water (placebo), and EMB groups were administered by oral gavage for 14 days. The superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) enzyme activities, thiobarbituric acid reactive substance (TBARS) and protein carbonyl (PC) levels, and adenosine triphosphatase (ATPases) enzymes, which are ion transport enzymes (Na⁺/K⁺ ATPase, Ca⁺² ATPase, Mg⁺² ATPase), acetylcholinesterase (AChE, neurotoxicity biomarker), and myeloperoxidase (MPO) enzyme activities (inflammatory biomarker), were measured by spectrophotometric methods. 8-Hydroxy-2'-deoxyguanosine level (8-OHdG, DNA oxidation biomarker) was measured by enzyme-linked immunosorbent analysis (ELISA) technique. The results showed a decrease in SOD, CAT and GPx enzyme activities in the brain tissue and an increase in GST enzyme activity in the EMB groups compared to the control group. Meanwhile, the enzyme activities of the ion transport enzymes Na⁺/K⁺ ATPase, Ca⁺² ATPase, and Mg⁺² ATPase, and AChE enzyme activity showed significant inhibition. In addition, MPO enzyme activity, 8-OHdG, PC, and TBARS levels were increased. The results showed that dose-dependent EMB exposure induced different physiological processes with enzymatic and biomolecular multi-biomarkers in the brain tissue of male mice and caused neurotoxic effects.

Effects of common environmental endocrine-disrupting chemicals on zebrafish behavior

Environmental endocrine-disrupting chemicals (EDCs), a type of exogenous organic pollutants, are ubiquitous in natural aquatic environments. Therefor, this review focused on the use of the zebrafish as a model to explore the effect of different EDCs on behavior, as well as the molecular mechanisms that drive these effects. Furthermore, our study summarizes the current knowledge on the neuromodulatory effects of different EDCs in zebrafish. This study also reviews the current state of zebrafish behavior research, in addition to the potential mechanisms of single and mixed pollutant-driven behavioral dysregulation at the molecular level, as well as the applications of zebrafish behavior experiments for neuroscience research. This review broadens our understanding of the influence of EDCs on zebrafish behavior and provides guidance for future research.

Effects of elevated CO2 on activities of protective and detoxifying enzymes in Frankliniella occidentalis and F. intonsa under spinetoram stress

BACKGROUND

Elevated CO₂ can directly affect the toxicity of insecticides to insects and the physiological response of insects to insecticides. Frankliniella occidentalis and F. intonsa are highly destructive pests that target horticultural crops. Spinetoram is an effective pesticide against thrips. This study sought to explore the effect of elevated CO₂ on efficacy of spinetoram against F. occidentalis and F. intonsa and effect of the spinetoram on activities of protective and detoxifying enzymes under elevated CO₂ . Notably, these enzymes can be exploited in further studies to develop interventions for thrips resistance management.

RESULTS

Toxicity bioassay showed that the LC₅₀ values of F. occidentalis and F. intonsa exposed to spinetoram at elevated CO₂ (800 μL L^-1 concentration) for 48 h was 0.08 and 0.006 mg L^-1 , respectively, which is 0.62 and 0.75 times of the values at ambient CO₂ (400 μL L^-1 concentration). The findings showed that elevated CO₂ decreased activities of the superoxide dismutase and acetylcholinesterase in thrips, while increasing the activities of carboxylesterase and glutathione S-transferase. However, spinetoram increased activities of protective and detoxifying enzymes in both thrips under the two CO₂ levels. Elevated CO₂ and spinetoram affect the physiological enzyme activity in thrips synergistically, and the activities of analyzed enzymes were generally higher in F. occidentalis than in F. intonsa.

CONCLUSION

Elevated CO₂ amplifies the efficacy of spinetoram on thrips, F. intonsa is more susceptibility to spinetoram than F. occidentalis and the latter showed better adaptation to adverse conditions than the former. © 2021 Society of Chemical Industry.

Lipid peroxidation functional state changes in patients with obstructive jaundice depending on the level of bilirubin in the blood

Obstructive jaundice (OJ) is the most common syndrome among diseases of the hepatopancreatoduodenal region and is found in 12-45% of cases. OJ may be benign and malignant etiology. Despite the evidence of the participation of bilirubin in reducing the bactericidal properties of neutrophils, there are no data currently on changes in the functioning of the antioxidant defense system depending on the level of bilirubin in the blood of patients with OJ of various origins. Research in this direction reveals the possibility for the development of pathogenetic recommendations for influencing these links of the pathogenesis of the disease. The study included men with OJ of non-malignant (OJNMG) (n = 47; mean age - 52.02 ± 5.18 years) and OJ of malignant genesis (OJMG) (I-II stages of the malignant process) (n = 45; mean age - 53.02 ± 4.8 years), divided into three subgroups, depending on the level of bilirubin in the blood. The indicators of practically healthy men as a control (n = 50, average age - 48.7 ± 3.9 years) were used. Spectrophotometric and statistical research methods were used. A statistically significant decrease of superoxide dismutase, glutathione-S-transferase, glutathione-peroxidase, ceruloplasmin, an increase in the values of diene conjugates, malondialdehyde in the group of patients with OJNMG relative to the control was revealed, regardless of the level of bilirubin in the blood. The presence of malignant genesis of the disease with more intense changes in the studied parameters relative to control is accompanied. Comparison of indicators between groups of patients with OJ of different genesis showed a decrease in the values of glutathione-S-transferase and an increase in the level of diene conjugates in patients with OJMG and the level of bilirubin less than 60 μmol / L, as well as an increase in the content of diene conjugates in patients with OJNMG and a level of bilirubin 60- 200 μmol / L in comparison with the corresponding groups of patients with OJNMG. Thus, both in the groups with OJNMG and in the groups with OJMG, there is a significant decrease in the activity of the main antioxidant enzymes and an increase in lipid peroxidation products, regardless of the level of bilirubin in the blood. The presence of malignant genesis is characterized by more intense differences. The revealed changes can serve as additional criteria for optimizing the diagnosis and treatment of this cohort of patients.

Peroxiredoxins as Markers of Oxidative Stress in IgA Nephropathy, Membranous Nephropathy and Lupus Nephritis

IgA nephropathy (IgAN), membranous nephropathy (MN), and lupus nephritis (LN) represent important causes of chronic kidney disease. They belong to the immune-mediated glomerulonephritis (GNs), and have distinct pathogenesis, distinct clinical courses, and variable responses to treatment. Therefore, specific diagnostic procedures are necessary for more effective patient management. Recently, a role for oxidative stress has been proposed in various renal disorders. Thus, molecules related to oxidative stress, such as 2-Cys-peroxiredoxins (PRDXs), may represent plausible candidates for biomarkers in renal pathologies. The aim of this study was to assess whether there are differences between individual GNs and healthy controls in the context of PRDXs serum concentration. We enrolled 108 patients with biopsy-proven IgAN (47), MN (26), LN (35) and 30 healthy age- and sex-matched controls. The serum concentrations of PRDX 1-5 were measured with ELISA assays and correlated with demographic and clinical data. The PRDXs' concentration varied depending on the GN type. We also observed an association of PRDXs with lower estimated glomerular filtration rates, complement, hemoglobin, and body mass index. Our study indicates that individual PRDX can play roles in pathophysiology of selected GNs and that their serum concentrations may become useful as a new supplementary diagnostic markers in IgAN, MN as well as LN. The results of this study open a new avenue for prospective research on PRDXs in renal diseases.

Protective Effects of Sesamol against Liver Oxidative Stress and Inflammation in High-Fat Diet-Induced Hepatic Steatosis

Chronic high-fat diet (HFD) is associated with the onset and progression of hepatic steatosis, and oxidative stress is highly involved in this process. The potential role of sesamol (SEM) against oxidative stress and inflammation at the transcriptional level in a mice model of hepatic steatosis is not known. In this study, we aimed to investigate the scavenging effects of SEM towards reactive oxygen generated by lipid accumulation in the liver of obese mice and to explore the mechanisms of protection. Markers of oxidative stress, vital enzymes involved in stimulating oxidative stress or inflammation, and nuclear transcription of Nrf2 were examined. Our results showed that SEM significantly inhibited the activity of the HFD-induced hepatic enzymes CYP2E1 and NOX2, associated with oxidative stress generation. Additionally, SEM reversed HFD-induced activation of NF-κB, a redox-sensitive transcription factor, and attenuated the expression of hepatic TNF-α, a proinflammatory molecule. Moreover, SEM enhanced HFD-induced hepatic Nrf2 nuclear transcription and increased the levels of its downstream target genes Ho1 and Nqo1, which indicated antiinflammation and antioxidant properties. Our study suggests that chronic HFD led to hepatic steatosis, while SEM exhibited protective effects on the liver by counteracting the oxidative stress and inflammation induced by HFD. The underlying mechanism might involve multiple pathways at the transcriptional level; the antioxidant defense mechanism was in partly mediated by the upregulation of Nrf2.

Effects of Sub-Chronic Exposure to Imidacloprid on Reproductive Organs of Adult Male Rats: Antioxidant State, DNA Damage, and Levels of Essential Elements

Although considered a good alternative to organophosphate pesticides, there are reports indicating adverse effects of neonicotinoid insecticides on reproduction. Our aim was to assess the effects of exposure to low doses of imidacloprid on antioxidant state, DNA damage, and concentration of essential elements in the testes and epididymis using a rat model. Adult male Wistar rats were orally treated with doses comparable to currently proposed health-based reference values: 0.06 (ADI), 0.80 (10× AOEL), or 2.25 (1/200 LD50) mg/kg b.w./day for 28 consecutive days. Exposure to 2.25 mg/kg b.w./day of imidacloprid resulted in a significantly lower testis weight (1.30 ± 0.17 g compared to 1.63 ± 0.15 g in controls). Treatment with 0.06 mg/kg b.w./day increased the level of reduced glutathione in the epididymis (73%), while the activities of epididymal glutathione peroxidase and superoxide dismutase significantly increased in all treated rats (74-92% and 26-39%, respectively). Exposure to imidacloprid resulted in a low, but significant, level of DNA damage in testicular sperm cells regardless of the concentration applied (<28% compared to the negative control). Higher concentrations of Mo were measured in the testes of rats treated with 0.80 and 2.25 mg/kg b.w./day (72.9 ± 7.9 and 73.9 ± 9.1 mg/g, respectively) compared to the control animals (60.5 ± 7.8 mg/g). Higher concentrations of Na were measured in the testes of rats treated with 2.25 mg/kg b.w./day (1679 ± 82 mg/g compared to 1562 ± 56 mg/g in controls). The fact that such low doses of imidacloprid were able to produce measurable biological effects calls for the further evaluation of this widely used insecticide.

Methods to evaluate the scavenging activity of antioxidants toward reactive oxygen and nitrogen species (IUPAC Technical Report)

This project was aimed to identify the quenching chemistry of biologically important reactive oxygen and nitrogen species (ROS/RNS, including radicals), to show antioxidant action against reactive species through H‐atom and electron transfer reactions, and to evaluate the ROS/RNS scavenging activity of antioxidants with existing analytical methods while emphasizing the underlying chemical principles and advantages/disadvantages of these methods. In this report, we focused on the applications and impact of existing assays on potentiating future research and innovations to evolve better methods enabling a more comprehensive study of different aspects of antioxidants and to provide a vocabulary of terms related to antioxidants and scavengers for ROS/RNS. The main methods comprise the scavenging activity measurement of the hydroxyl radical (•OH), dioxide(•1–) (O2 •–: commonly known as the superoxide radical), dihydrogen dioxide (H2O2: commonly known as hydrogen peroxide), hydroxidochlorine (HOCl: commonly known as hypochlorous acid), dioxidooxidonitrate(1–) (ONOO−: commonly known as the peroxynitrite anion), and the peroxyl radical (ROO•). In spite of the diversity of methods, there is currently a great need to evaluate the scavenging activity of antioxidant compounds in vivo and in vitro. In addition, there are unsatisfactory methods frequently used, such as non-selective UV measurement of H2O2 scavenging, producing negative errors due to incomplete reaction of peroxide with flavonoids in the absence of transition metal ion catalysts. We also discussed the basic mechanisms of spectroscopic and electrochemical nanosensors for measuring ROS/RNS scavenging activity of antioxidants, together with leading trends and challenges and a wide range of applications. This project aids in the identification of reactive species and quantification of scavenging extents of antioxidants through various assays, makes the results comparable and more understandable, and brings a more rational basis to the evaluation of these assays and provides a critical evaluation of existing ROS/RNS scavenging assays to analytical, food chemical, and biomedical/clinical communities by emphasizing the need for developing more refined, rapid, simple, and low‐cost assays and thus opening the market for a wide range of analytical instruments, including reagent kits and sensors.

Alamandine protects against renal ischaemia-reperfusion injury in rats via inhibiting oxidative stress

OBJECTIVE

This study was to determine whether alamandine (Ala) could reduce ischaemia and reperfusion (I/R) injury of kidney in rats.

METHODS

Renal I/R was induced by an occlusion of bilateral renal arteries for 70 min and a 24-h reperfusion in vivo, and rat kidney proximal tubular epithelial cells NRK52E were exposed to 24 h of hypoxia and followed by 3-h reoxygenation (H/R) in vitro.

RESULTS

The elevated serum creatinine (Cr), blood cystatin C (CysC) and blood urea nitrogen (BUN) levels in I/R rats were inhibited by Ala treatment. Tumour necrosis factor alpha (TNF)-α, IL-1β, IL-6, cleaved caspase-3, cleaved caspase-8 and Bax were increased, and Bcl2 was reduced in the kidney of I/R rats, which were reversed by Ala administration. Ala reversed the increase of TNF-α, IL-1β, IL-6, cleaved caspase-3, cleaved caspase-8 and Bax and the decrease of Bcl2 in the H/R NRK52E cells. Ala could also inhibit the increase of oxidative stress levels in the kidney of I/R rats. NADPH oxidase 1 (Nox1) overexpression reversed the improving effects of Ala on renal function, inflammation and apoptosis of I/R rats.

CONCLUSION

These results indicated that Ala could improve renal function, attenuate inflammation and apoptosis in the kidney of I/R rats via inhibiting oxidative stress.

Transcriptomic and Metabolomic Analyses Provide Insights into the Enhancement of Torulene and Torularhodin Production in Rhodotorula glutinis ZHK under Moderate Salt Conditions

Carotenoids are a group of tetraterpene pigments widely used in the food, pharmaceutical, and cosmetic industries. Torulene, torularhodin, and β-carotene, three principal carotenoids synthesized by Rhodotorula glutinis ZHK, possess strong health-promoting properties such as antioxidant, provitamin A, and antitumor. Here, the effect of different salt conditions on carotenoids production of R. glutinisZHK was investigated. The results showed that the total carotenoids were significantly enhanced in 0.5 M (3.91 mg/L) and 0.75 M (5.41 mg/L) NaCl treatments than that in 1.0 M (0.35 mg/L) and control (1.42 mg/L) after 120 h of cultivation. Of which, the increase in torulene and torularhodin production acts as the main contributor to the enhancement of total carotenoids. Transcriptome profiling revealed that salt stress efficiently promotes the gene expression of crtI, which could explain the molecular mechanisms of the enhanced torulene and torularhodin production under salt stress. Further experiments indicated that torulene and torularhodin play an important role in quenching excrescent reactive oxygen species induced by salt stress. Together, the present study reports an effective strategy for simultaneously improving torulene and torularhodin production in R. glutinis ZHK.

Ozone pollution, oxidative stress, synaptic plasticity, and neurodegeneration

INTRODUCTION

Overpopulation and industrial growth result in an increase in air pollution, mainly due to suspended particulate matter and the formation of ozone. Repeated exposure to low doses of ozone, such as on a day with high air pollution levels, results in a state of chronic oxidative stress, causing the loss of dendritic spines, alterations in cerebral plasticity and in learning and memory mechanisms, and neuronal death and a loss of brain repair capacity. This has a direct impact on human health, increasing the incidence of chronic and degenerative diseases.

DEVELOPMENT

We performed a search of the PubMed, Scopus, and Google Scholar databases for original articles and reviews published between 2000 and 2018 and addressing the main consequences of ozone exposure on synaptic plasticity, information processing in cognitive processes, and the alterations that may lead to the development of neurodegenerative diseases.

CONCLUSIONS

This review describes one of the pathophysiological mechanisms of the effect of repeated exposure to low doses of ozone, which causes loss of synaptic plasticity by producing a state of chronic oxidative stress. This brain function is key to both information processing and the generation of structural changes in neuronal populations. We also address the effect of chronic ozone exposure on brain tissue and the close relationship between ozone pollution and the appearance and progression of neurodegenerative diseases.

Integrated non-targeted lipidomics and metabolomics analyses for fluctuations of neonicotinoids imidacloprid and acetamiprid on Neuro-2a cells

Neonicotinoid insecticides are widely used for pest control. However, they are highly water-soluble and easily ingested by organisms, posing potential health risks. In this study, cytotoxicity evaluations of imidacloprid and acetamiprid were conducted in Neuro-2a cells by obtaining their half maximal inhibitory concentration (IC₅₀ values) (1152.1 and 936.5 μM, respectively). The toxic effects at the IC₁₀ and IC₂₀ on cell metabolism were determined by integrated non-targeted lipidomics and metabolomics analyses. Changes in the concentration of acetamiprid caused the most drastic perturbations of metabolism in Neuro-2a cells. Altogether, the detected lipids were mainly attributed to triglyceride, phosphatidylcholine (PC), and diglyceride. These three categories of lipids accounted for more than 67% of the sum in Neuro-2a cells. A total of 14 lipids and other 40 metabolites were screened as differential metabolites based on multivariate data analysis, and PCs were most frequently observed with a proportion of 25.9%. The results demonstrated that lipid metabolism should be paid considerable attention after imidacloprid and acetamiprid exposure. Pathway analysis showed that the metabolisms of glycerophospholipid, sphingolipid, and glutathione were the dominant pathways that were interfered. The present study is the first to investigate the cellular toxic mechanisms after separate imidacloprid and acetamiprid exposure by using lipidomics and metabolomics simultaneously. This research also provides novel insights into the evaluation of the ecological risk of imidacloprid and acetamiprid and contribute to the study of toxicity mechanism of these neonicotinoid insecticides to animals and humans in the future.

Lactobacillus plantarum Exhibits Antioxidant and Cytoprotective Activities in Porcine Intestinal Epithelial Cells Exposed to Hydrogen Peroxide

Probiotics are widely used for protection against stress-induced intestinal dysfunction. Oxidative stress plays a critical role in gastrointestinal disorders. It is established that probiotics alleviate oxidative stress; however, the mechanism of action has not been elucidated. We developed an in vitro intestinal porcine epithelial cells (IPEC-J2) model of oxidative stress to explore the antioxidant effect and potential mode of action of Lactobacillus plantarum ZLP001. The IPEC-J2 cells were preincubated with and without L. plantarum ZLP001 for 3 h and then exposed to hydrogen peroxide (H₂O₂) for 4 h. Pretreatment with L. plantarum ZLP001 protected IPEC-J2 cells against H₂O₂-induced oxidative damage as indicated by cell viability assays and significantly alleviated apoptosis elicited by H₂O₂. L. plantarum ZLP001 pretreatment decreased reactive oxygen species production and the cellular malondialdehyde concentration and increased the mitochondrial membrane potential compared with H₂O₂ treatment alone, suggesting that L. plantarum ZLP001 promotes the maintenance of redox homeostasis in the cells. Furthermore, L. plantarum ZLP001 regulated the expression and generation of some antioxidant enzymes, thereby activating the antioxidant defense system. Treatment with L. plantarum ZLP001 led to nuclear erythroid 2-related factor 2 (Nrf2) enrichment in the nucleus compared with H₂O₂ treatment alone. Knockdown of Nrf2 significantly weakened the alleviating effect of L. plantarum ZLP001 on antioxidant stress in IPEC-J2 cells, suggesting that Nrf2 is involved in the antioxidative effect of L. plantarum ZLP001. Collectively, these results indicate that L. plantarum ZLP001 is a promising probiotic bacterium that can potentially alleviate oxidative stress.

Chemical composition, bioactive compounds extraction, and observed biological activities from jussara (Euterpe edulis): The exotic and endangered Brazilian superfruit

In this article, we reviewed studies on the fruits of the jussara palm (Euterpe edulis Martius), an endangered Brazilian Atlantic Forest palm tree, also coined as "Superfruit." We summarized the chemical components of the pulp and observed biological activities in murine and humans, as well as the best practices involving the extraction of its target compounds, bioavailability, and stability of extracts. Jussara has shown a rich phenolic profile that justifies its antioxidant properties, in addition to a considerable lipidic and energetic value. As the main feature, the fruit possesses large amounts of anthocyanins that can be commercially explored as a food additive or cosmetic colorants. Recent studies emphasized jussara's antioxidant, anti-inflammatory, and cardioprotective capabilities via reshaping of the gut microbiota. Further knowledge is needed to establish bioavailability and optimal serving size, as many of its antioxidant compounds go under chemical bioconversion in the intestinal tract. While extraction of phenolic compounds, anthocyanins, and oils have interesting results, more studies are required in order to reduce the use of conventional organic solvents and improve their stability and shelf life when added to food products, an area in which nanotechnology seems promising.

Novel arylidene malonate derivative, KM-34, showed neuroprotective effects on in vitro and in vivo models of ischemia/reperfusion

Cerebral ischemia constitutes the most frequent type of cerebrovascular disease. The reduction of blood supply to the brain initiates the ischemic cascade starting from ionic imbalance to subsequent glutamate excitotoxicity, neuroinflammation and oxidative stress, eventually causing neuronal death. Previously, the authors have demonstrated the in vitro cytoprotective and antioxidant effects of a new arylidene malonate derivative, KM-34, against oxidizing agents like hydrogen peroxide, glutamate or Fe3+/ascorbate. Here, we examined for the first time the neuroprotective effect of KM-34 on ischemia/reperfusion models. In vitro, treatment with 10 and 50 μM KM-34 reduced the cellular death (propidium iodide incorporation) induced by oxygen glucose deprivation (OGD) in rat organotypic hippocampal slices cultures. In vivo, stroke was induced in male Wistar rats through middle cerebral artery occlusion (MCAO), followed by 23 h of reperfusion. KM-34 was orally administered 105 min after MCAO onset. We noticed that 1 mg/kg KM-34 reduced infarct volume and neurological score, and increased the latency to fall in the Hanging Wire test compared to vehicle-treated ischemic animals. While ischemic and sham-operated groups showed similar horizontal locomotor activity, vertical counts decreased after MCAO, suggesting that vertical movements are more sensitive to the ischemic injury. Treatment with KM-34 also alleviated the mitochondrial impairment (ROS generation, swelling and membrane potential dissipation) induced by transient MCAO but not significant alterations were found in oxidative stress parameters. Overall, the study provides preclinical evidences confirming the neuroprotective effects of a novel synthetic molecule and paved the way for future investigations regarding its therapeutic potential against brain ischemia/reperfusion injury.

Oxidative Stress and Hypertension

A link between oxidative stress and hypertension has been firmly established in multiple animal models of hypertension but remains elusive in humans. While initial studies focused on inactivation of nitric oxide by superoxide, our understanding of relevant reactive oxygen species (superoxide, hydrogen peroxide, and peroxynitrite) and how they modify complex signaling pathways to promote hypertension has expanded significantly. In this review, we summarize recent advances in delineating the primary and secondary sources of reactive oxygen species (nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, endoplasmic reticulum, and mitochondria), the posttranslational oxidative modifications they induce on protein targets important for redox signaling, their interplay with endogenous antioxidant systems, and the role of inflammasome activation and endoplasmic reticular stress in the development of hypertension. We highlight how oxidative stress in different organ systems contributes to hypertension, describe new animal models that have clarified the importance of specific proteins, and discuss clinical studies that shed light on how these processes and pathways are altered in human hypertension. Finally, we focus on the promise of redox proteomics and systems biology to help us fully understand the relationship between ROS and hypertension and their potential for designing and evaluating novel antihypertensive therapies.

Effects of low-level imidacloprid oral exposure on cholinesterase activity, oxidative stress responses, and primary DNA damage in the blood and brain of male Wistar rats

Imidacloprid is a neonicotinoid insecticide that acts selectively as an agonist on insect nicotinic acetylcholine receptors. It is used for crop protection worldwide, as well as for non-agricultural uses. Imidacloprid systemic accumulation in food is an important source of imidacloprid exposure. Due to the undisputable need for investigations of imidacloprid toxicity in non-target species, we evaluated the effects of a 28-day oral exposure to low doses of imidacloprid (0.06 mg/kg b. w./day, 0.8 mg/kg b. w./day and 2.25 mg/kg b. w./day) on cholinesterase activity, oxidative stress responses and primary DNA damage in the blood and brain tissue of male Wistar rats. Exposure to imidacloprid did not cause significant changes in total cholinesterase, acetylcholinesterase and butyrylcholinesterase activities in plasma and brain tissue. Reactive oxygen species levels and lipid peroxidation increased significantly in the plasma of rats treated with the lowest dose of imidacloprid. Activities of glutathione-peroxidase in plasma and brain and superoxide dismutase in erythrocytes increased significantly at the highest applied dose. High performance liquid chromatography with UV diode array detector revealed the presence of imidacloprid in the plasma of all the treated animals and in the brain of the animals treated with the two higher doses. The alkaline comet assay results showed significant peripheral blood leukocyte damage at the lowest dose of imidacloprid and dose-dependent brain cell DNA damage. Oral 28-day exposure to low doses of imidacloprid in rats resulted in detectable levels of imidacloprid in plasma and brain tissue that directly induced DNA damage, particularly in brain tissue, with slight changes in plasma oxidative stress parameters.