Lipid peroxidation: a review of causes, consequences, measurement and dietary influences

Daphnia stress response to environmental concentrations of chloramphenicol-multi-omics approach

Commonly used medicines, when discarded or improperly disposed of, are known to contaminate freshwater ecosystems. Pharmaceuticals can be toxic and mutagenic, and can modify freshwater organisms, even at environmentally relevant concentrations. Chloramphenicol (CAP) is an antibiotic banned in Europe. However, it is still found in surface waters around the world. The aim of this study was to evaluate the impact of chloramphenicol contamination in freshwater on the model organism Daphnia magna. Specific life history parameters, proteome, and host-associated microbiome of four D. magna clones were analyzed during a three-generation exposure to CAP at environmental concentrations (32 ng L-1). In the first generation, no statistically significant CAP effect at the individual level was detected. After three generations, exposed animals were smaller at first reproduction and on average produced fewer offspring. The differences in D. magna's life history after CAP treatment were in accordance with proteome changes. D. magna's response to CAP presence indicates the high stress that the tested organisms are under, e.g., male production, upregulation of ubiquitin-conjugating enzyme E2 and calcium-binding protein, and downregulation of glutathione transferase. The CAP-exposed D. magna proteome profile confirms that CAP, being reactive oxygen species (ROS)-inducing compounds, contributes to structural changes in mitochondria. Microbiome analysis showed a significant difference in the Shannon index between control and CAP-exposed animals, the latter having a more diverse microbiome. Multilevel analyses, together with long exposure in the laboratory imitating conditions in a polluted environment, allow us to obtain a more complete picture of the impact of CAP on D. magna.

A new photoionization-induced substitution reaction chemical ionization time-of-flight mass spectrometry for highly sensitive detection of trace exhaled ethylene

Highly sensitive and rapid detection of ethylene, the smallest alkene of great significance in human physiological metabolism remains a great challenge. In this study, we developed a new photoionization-induced substitution reaction chemical ionization time-of-flight mass spectrometry (PSCI-TOFMS) for trace exhaled ethylene detection. An intriguing ionization phenomenon involving a substitution reaction between the CH2Br2+ reactant ion and ethylene molecule was discovered and studied for the first time. The formation of readily identifiable [CH2Br·C2H4]+ product ion greatly enhanced the ionization efficiency of ethylene, which led to approximately 800-fold improvement of signal intensity over that in single photon ionization mode. The CH2Br2+ reactant ion intensity and ion-molecule reaction time were optimized, and a Nafion tube was employed to eliminate the influence of humidity on the ionization of ethylene. Consequently, a limit of detection (LOD) as low as 0.1 ppbv for ethylene was attained within 30 s at 100 % relative humidity. The application of PSCI-TOFMS on the rapid detection of trace amounts of exhaled ethylene from healthy smoker and non-smoker volunteers demonstrated the satisfactory performance and potential of this system for trace ethylene measurement in clinical diagnosis, atmospheric measurement, and process monitoring.

Effect of vitamin E, D-limonene, and their combination on nulliparous rabbit reproductive performance

Oxidative status is important in reproductive performance and using two natural antioxidants is more beneficial than one in nulliparous rabbits. The goal, effect of vitamin E (VitE), D-limonene (DL), and VitE+DL on maternal LBW (MLBW), conception (CR), pregnancy (PR), and kindling rates (KR), gestation length (GL), total litter size at birth (TLSB) and weaning (TLSW), live kits at birth (LKB) and weaning (LKW), dead kits at birth (DKB) and weaning (DKW), kits mortality rate at weaning (KMRW), Kit weight at birth (KWB) and weaning (KWW), total kit weight at birth (TKWB) and weaning (TKWW), and concentrations of progesterone (P4) and Malondialdehyde (MDA), during first two pregnancies. A total of 24 healthy female WNZ rabbits were randomly selected and assigned into four groups (6/each). Control (animals injected with 1.0 mL propylene glycol), VitE (60 mg IM injection/animal, 2X/week pre-mating and 3X post-mating until mid-pregnancy, DL (20 mg IM injection/animal, 2X/week pre-mating and 1X at mating, and VitE+DL (IM injection/animal with the same doses and times applied in VitE and DL groups. All animals were treated during 1st pregnancy only. The results confirmed that animals treated with VitE+DL gained significant maternal LBW in 1st pregnancy, reduced dead kit number at birth and kit mortality rate at weaning, increased live kits and total kit weight at birth and weaning in the two pregnancies, and also increased significantly kit weight at birth and weaning in the treatments than controls in the two pregnancies, and DL was greater in 1st pregnancy. Progesterone concentrations in mid-pregnancy rose significantly in VitE+DL during 1st pregnancy and DL in 2nd pregnancy. Malondialdehyde concentrations dropped significantly in VitE and VitE+DL in mid-pregnancy in the two pregnancies. Eventually, the integration of VitE and DL displayed their unique properties for improving productive and reproductive performance in nulliparous rabbits.

Effect of Kinins on the Hepatic Oxidative Stress in Mice Treated with a Methionine-Choline Deficient Diet

Non-alcoholic fatty liver is the leading cause of hepatic disease worldwide and ranges from simple steatosis to non-alcoholic steatohepatitis (NASH) due to cell injury, oxidative stress, and apoptosis. The kinins' role in the liver has been studied in experimental fibrosis, partial hepatectomy, and ischemia-reperfusion and is related to cell death and regeneration. We investigated its role in experimental NASH induced by a methionine-choline deficient diet for 4 weeks. After that, liver perfusion was performed, and bradykinin (BK) or des-Arg9-BK was infused. Cell death was evaluated by cathepsin-B and caspase-3 activity and oxidative stress by catalase (CAT), glutathione S-transferase, and superoxide dismutase (SOD) activities, as well as malondialdehyde and carbonylated proteins. In control livers, DABK increased CAT activity, which was reversed by antagonist DALBK. In the NASH group, kinins tend to decrease antioxidant activity, with SOD activity being significantly reduced by BK and DABK. Malondialdehyde levels increased in all NASH groups, but carbonylated protein did not. DABK significantly decreased cathepsin-B in the NASH group, while caspase-3 was increased by BK in control animals. Our results suggest that B1R and/or B2R activation did not induce oxidative stress but affected the antioxidant system, reducing SOD in the NASH group.

Variation of the genes encoding antioxidant enzymes SOD2 (rs4880), GPX1 (rs1050450), and CAT (rs1001179) and susceptibility to male infertility: a genetic association study and in silico analysis

Enzymatic factors including superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) are among the most important protective antioxidant systems in human semen. This study was conducted to investigate the association between the activities of the mentioned enzymes in semen and also the association between SOD2 rs4880, GPX1 rs1050450, and CAT rs1001179 polymorphisms with male infertility, which was followed by a bioinformatics approach. In a case-control study, 223 infertile men and 154 healthy fertile men were included in the study. After extracting genomic DNA from semen samples, the genotype of rs1001179, rs1050450, and rs4880 polymorphisms was determined using the PCR-RFLP. Next, the activities of SOD, CAT, and GPX enzymes were also measured in semen. Bioinformatics software was used to investigate the effect of polymorphisms on the function of genes. Data analysis indicated that rs1001179 polymorphisms were not associated with male infertility. But our data revealed that the rs1050450 polymorphism is associated with a reduced risk of male infertility as well as asthenozoospermia and teratozoospermia. In addition, rs4880 polymorphism was associated with an increased risk of male infertility as well as teratozoospermia. Further analysis showed that the activity of the CAT enzyme in the infertile group is significantly higher than in the fertile group, but the activity of GPX and SOD enzymes in the infertile group is significantly lower than in the fertile group. Bioinformatic analysis showed that rs1001179 polymorphism affects the transcription factors binding site upstream of the gene, while rs1050450 and rs4880 polymorphisms had an essential role in protein structure and function. On the other hand, rs1050450 (T allele) was exposed to a reduced risk of male infertility and may be a protective factor. And SOD2 rs4880 (C allele) is associated with an increased risk of male infertility, and it is considered a risk factor for male infertility. To reach accurate results, we recommend that the study of SOD2 rs4880 and GPX1 rs1050450 polymorphism effects in the different populations with a larger sample size and meta-analysis are needed.

The role of lipid oxidation on electrical properties of planar lipid bilayers and its importance for understanding electroporation

Electroporation is a useful tool for the manipulation with the cell membrane permeability. Underlying physicochemical processes taking place at the molecular level during electroporation are relatively well studied. However, various processes remain unknown, one of them is lipid oxidation, a chain reaction that causes degradation of lipids, and might explain the long-lasting membrane permeability after the electric field has ceased. The aim of our study was to observe the differences in the electrical properties of planar lipid bilayers, as in vitro cell membrane models, due to lipid oxidation. Phospholipids were chemically oxidized and oxidation products were analysed using mass spectrometry. Electrical properties, resistance R (Ω) and capacitance C (F) were measured using an LCR meter. Using a previously developed measuring device, a linear increasing signal was applied to a stable bilayer in order to measure its breakdown voltage U_br (V) and lifetime t_br (µs). We observed an increase in conductance and capacitance of the oxidized planar lipid bilayers when compared to their non-oxidized counterparts. With increasing lipid oxidation, the core of the bilayer becomes more polar, and consequently more permeable. Our findings can explain the long-lasting permeability of the cell membrane after electroporation.

Effects of N-Acetylcysteine Supplementation on Oxidative Stress and Expression of Apoptosis-Related Genes in Testicular Tissue of Rats Exposed to Lead

BACKGROUND

Lead occupational exposure is now a main concern in the modern world. Lead is a non-biodegradable element with multi-devastating effects on different organs. Acute or chronic exposure to lead is reported to be one of the most important causes of infertility both in males and females basically by inducing oxidative stress and apoptosis.

OBJECTIVES

The current study scrutinized the mitigating effects of N-acetylcysteine (NAC) on lead toxicity, oxidative stress, and apoptotic/anti-apoptotic genes in the testis tissues of male rats.

METHODS

Rats were randomly divided into a control group (G1) and four study groups treated with single and continuous doses of lead with and without NAC administration. Malondialdehyde (MDA), total antioxidant capacity (TAC), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were analyzed as oxidative stress biomarkers and the expression of apoptosis-related genes was studied using RT-PCR.

RESULTS

Continuous exposure to lead caused a significant decrease in sperm count, motility, viability, and morphology (P < 0.001). Number of germinal cells, Leydig cells, spermatocytes, and the diameter of seminiferous tubule were significantly decreased (P < 0.001) in G3 group. Continuous exposure to lead significantly decreased TAC content, but increased the levels of MDA and 8-OHdG (P < 0.001). Administration of continuous dose of lead dramatically increased expression of Bax, Caspase-3, Caspase-8, Cytochrome-C, MMP2, and MMP9 genes in testicular tissue. NAC treatments not only improved morphological changes and sperm quality, but also enhanced antioxidant balance and modulated apoptosis process in testicular tissue of rats.

CONCLUSION

Lead exposure strongly motivated testicular cells towards apoptosis, caused an oxidant/antioxidant imbalance, and decreased sperm quality along with morphological changes in testis cells. NAC treatments was associated with protective effects on testicular tissue mainly by rebalancing of the antioxidants capacity, as well as downregulation of apoptosis-related genes.

Nature-Inspired Bioactive Compounds: A Promising Approach for Ferroptosis-Linked Human Diseases?

Ferroptosis is a type of cell death driven by iron overload and lipid peroxidation. It is considered a key mechanism in the development of various diseases such as atherosclerosis, Alzheimer, diabetes, cancer, and renal failure. The redox status of cells, such as the balance between intracellular oxidants (lipid peroxides, reactive oxygen species, free iron ions) and antioxidants (glutathione, glutathione Peroxidase 4), plays a major role in ferroptosis regulation and constitutes its principal biomarkers. Therefore, the induction and inhibition of ferroptosis are promising strategies for disease treatments such as cancer or neurodegenerative and cardiovascular diseases, respectively. Many drugs have been developed to exert ferroptosis-inducing and/or inhibiting reactions, such as erastin and iron-chelating compounds, respectively. In addition, many natural bioactive compounds have significantly contributed to regulating ferroptosis and ferroptosis-induced oxidative stress. Natural bioactive compounds are largely abundant in food and plants and have been for a long time, inspiring the development of various low-toxic therapeutic drugs. Currently, functional bioactive peptides are widely reported for their antioxidant properties and application in human disease treatment. The scientific evidence from biochemical and in vitro tests of these peptides strongly supports the existence of a relationship between their antioxidant properties (such as iron chelation) and ferroptosis regulation. In this review, we answer questions concerning ferroptosis milestones, its importance in physiopathology mechanisms, and its downstream regulatory mechanisms. We also address ferroptosis regulatory natural compounds as well as provide promising thoughts about bioactive peptides.

The therapeutic effect of co-administration of pentoxifylline and zinc in men with idiopathic infertility

Pentoxifylline is a derivative of methylxanthine that affects sperm motility. Also, zinc is an antioxidant that is involved in the activation of antioxidant enzymes. This study aimed to evaluate the effect of co-administration of pentoxifylline, and zinc in men with idiopathic infertility. In the present study, men with idiopathic infertility were identified and randomly divided into four groups: pentoxifylline, zinc, pentoxifylline + zinc, and placebo. According to the grouping, the patients received pentoxifylline and zinc for 3 months. Then, sperm parameters, biochemical factors, reproductive hormones, inflammatory factors, and DNA damage were evaluated before and after intervention. Data analysis was performed using SPSS software. Pentoxifylline and zinc were significantly effective in improving biochemical parameters, inflammatory factors, concentration, and motility of sperm. Pentoxifylline did not affect sperm morphology and reproductive hormones. However, in the zinc and zinc + pentoxifylline groups, a significant increase in normal morphology and reproductive hormones was observed. In the pentoxifylline group, sperm DNA fragmentation increased significantly, while in the zinc and zinc + pentoxifylline group, DNA fragmentation reduced significantly. Because of the role of zinc in protecting sperm chromatin, it is recommended that zinc and pentoxifyllinebe prescribed simultaneously. Clinical trial code: NCT05156684.

Empagliflozin enhances neuroplasticity in rotenone-induced parkinsonism: Role of BDNF, CREB and Npas4

AIMS

Parkinsonism is characterized by degeneration of dopaminergic neurons and impairment in neuroplasticity. Empagliflozin (EMPA) is an anti-diabetic drug that has been shown to improve cognitive dysfunctions and exerted antioxidant and anti-inflammatory effects in different models. This study aimed to determine the neuroprotective effects of EMPA against rotenone (ROT)-induced parkinsonism.

MAIN METHODS

ROT (1.5 mg/kg) was injected subcutaneously three times per week for two successive weeks. Mice were treated with EMPA (3 and 10 mg/kg, orally) for one week prior ROT administration and for another two weeks along with ROT. After that, motor functions and histopathological changes were assessed, and brains were isolated for biochemical analyses and immunohistochemical investigation.

KEY FINDINGS

Results indicated that, in a dose dependent manner, EMPA improved motor functions and histopathological changes induced by ROT, increased brain content of reduced glutathione (GSH), dopamine (DA), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), nuclear factor erythroid 2-related factor 2 (Nrf2), inositol trisphosphate (IP3), calcium (Ca²⁺), calcium/calmodulin-dependent protein kinase type IV (CaMKIV) and phospho-Protein kinase B (p-Akt) levels compared to ROT group. Additionally, EMPA decreased the levels of malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α), and inactivated glycogen synthase kinase-3 beta (GSK-3β). Improvement in neuroplasticity was also observed indicated by elevation in brain derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), and neuronal PAS domain Protein 4 (Npas4).

SIGNIFICANCE

EMPA improved motor functions possibly through improving neuroplasticity markers and antioxidant, anti-inflammatory, and neuroprotective effects in a dose dependent manner.

Role of Oxidative Stress and Lipid Peroxidation in the Pathophysiology of NAFLD

Non-alcoholic fatty liver disease (NAFLD) is characterised by an excess of hepatic fat that can progress to steatohepatitis, fibrosis, cirrhosis and hepatocarcinoma. The imbalance between lipid uptake/lipogenesis and lipid oxidation/secretion in the liver is a major feature of NAFLD. Given the lack of a non-invasive and reliable methods for the diagnosis of non-alcoholic steatohepatitis (NASH), it is important to find serum markers that are capable of discriminating or defining patients with this stage of NASH. Blood samples were obtained from 152 Caucasian subjects with biopsy-proven NAFLD due to persistently elevated liver enzyme levels. Metabolites representative of oxidative stress were assessed. The findings derived from this work revealed that NAFLD patients with a NASH score of ≥ 4 showed significantly higher levels of lipid peroxidation (LPO). Indeed, LPO levels above the optimal operating point (OOP) of 315.39 μM are an independent risk factor for presenting a NASH score of ≥ 4 (OR: 4.71; 95% CI: 1.68−13.19; p = 0.003). The area under the curve (AUC = 0.81, 95% CI = 0.73−0.89, p < 0.001) shows a good discrimination ability of the model. Therefore, understanding the molecular mechanisms underlying the basal inflammation present in these patients is postulated as a possible source of biomarkers and therapeutic targets in NASH.

Protecting Effects of N-acetyl Cysteine Supplementation Against Lead and Cadmium-Induced Brain Toxicity in Rat Models

We aimed to investigate mitigating effects of N-acetylcysteine (NAC) on the oxidative stress, apoptosis and Parkinson's disease (PD)-related genes in the brain tissue of male rats exposed to continuous doses of cadmium and lead. Rats were randomly divided into five groups, including G1 (control), G2 (continuous dose of Cd), G3 (continuous dose of Pb), G4 (continuous dose of Cd + NAC), and G5 (continuous dose of Pb + NAC). Biomarkers of oxidative stress, malondialdehyde (MDA), and total antioxidant capacity (TAC) were measured. Expression of PD- and apoptosis-related genes was considered using RT-PCR. Chronic exposure to these heavy metals was associated with accumulation of Pb and Cd in the brain and blood and caused severe morphological changes in the brain, as well as decreased body and brain weights. Continuous exposure to Cd and Pb significantly decreased TAC content and SOD expression but increased MDA level in the brain tissues (P < 0.001). A significant increase was observed in expression of PD-related genes, Parkin, Pink1, LRRK2, SNCA, and Caspase-3 in the brain tissues following exposure to Cd and Pb. Pb exhibited stronger toxicity on the brain tissue compared to Cd. NAC supplementation not only improved morphological changes, but also compensated antioxidant capacity and expression of apoptosis- and PD-related genes in the brain tissues when compared to rats exposed to Pb and Cd alone. Chronic exposure to Pb and Cd is strongly associated with accumulation of these heavy metals in the brain, morphological changes, antioxidants depletion, oxidative stress, and brain cells apoptosis. Changes in expression of PD-related genes indicate the higher risk of PD among individuals who are chronically exposed to these heavy metals. NAC can protect brain tissue against Pb and Cd toxicity by elevating antioxidants capacity, mitigating oxidative stress, apoptosis, and down-regulating of PD-related genes.

The Effect of Dietary Inclusion of Microalgae Schizochytrium spp. on Ewes’ Milk Quality and Oxidative Status

An unprecedented challenge for nutritionists arises during the 21st century in order to produce highly nutritious and functional food which promotes human health. Polyunsaturated fatty acids (PUFA) that are highly contained in microalgae have broadly been confirmed for preventing cardiovascular diseases and regulating immune-oxidative status. However, their optimum dietary inclusion level needs to be defined since PUFA are prone to oxidation. For this purpose, 24 cross-bred dairy ewes, were separated into four groups (n = 6) and were fed with different levels of microalgae Schizochytrium spp. [0 (CON, no microalgae), 20 (SC20), 30 (SC30) and 40 (SC40) g/ewe/day] for 60 days. The results showed that although the production parameters were not impaired, milk fat content was decreased in medium and high-level supplemented groups while protein content was suppressed only for the medium one. Concerning the fatty acids (FA) profile, the proportions of C_14:0, trans C_18:1, trans-11 C_18:1, cis-9, trans-11 C_18:2, trans-10, cis-12 C_18:2, C_20:5 (EPA), C_22:5n-6 (DPA), C_22:6n-3 (DHA), the total ω3 FA and PUFA were significantly increased, while those of C_18:0, cis-9 C_18:1 and C_18:2n-6c were decreased in the milk of treated ewes. Additionally, in the S40 group an oxidative response was induced, observed by the increased malondialdehyde (MDA) levels in milk and blood plasma. In conclusion, the dietary inclusion of 20 g Schizochytrium spp./ewe/day, improves milks’ fatty acid profile and seems to be a promising way for producing ω3 fatty acid-enriched dairy products.

The effect of vitamin E on the lipid environment of rat hepatocyte membranes

Tocopherol is one of the known beneficial natural antioxidants ensuring the optimal level of functioning of mammalian organisms. Numerous in vitro and in vivo experiments have shown that the biological role of vitamin E is to prevent the development of pathologies caused by oxidative stress. In particular, the role of enzymatic factors of lipid peroxidation and related inflammation as a result of eicosanoid synthesis was clearly shown. We studied changes in the structural and functional state of hepatocyte membranes in the classical model of E-hypovitaminosis caused by long-term (70 days) insufficient intake of vitamin E in the diet of rats. The test components were determined spectrophotometrically after appropriate chromatographic procedures. The amount of total and individual leukotrienes was determined by ELISA. Prolonged tocopherol deficiency in rats caused a 49.4% decrease in tocopherol, more than 27.0% – in cholesterol. Of the 8 individual phospholipids studied, 6 showed significant changes: a decrease in cardiolipin and phosphatidylserine, and an increase in phosphatidylethanolamine by 3.24 times, an increse in lysophosphatidylcholine by 86.9%, in phospha­tidylcholine by 52.8%, and in sphingomyelin by 30.6%, relative to control. There were changes in the levels of unsaturated fatty acids playing a significant role in the development of functional disorders in cells and affecting the metabolism of ecosanoids derived from arachidonic acid by the 5-lipoxygenase oxidation pathway. Changes in the levels of total and individual cysteinyl leukotrienes in the state of E-hypovitaminosis were revealed. Restoration of vitamin E intake returns most of the studied indicators such as tocopherol, cholesterol, polyunsaturated fatty acids to the control levels and activates the processes of sequential conversion of leukotrienes in the body of rats. The obtained results indicate the potentiating effect of vitamin E on metabolic processes in the body as a whole and in hepatocytes and eicosanoid metabolism. The degree of tocopherol intake allows one to influence the course of inflammatory processes associated with eicosanoids, not only through the impact on precursors, but also on the utilization of metabolites, including leukotrienes.

Effects of Sulfur amino acid supplementation on Broiler Chickens Exposed to Acute and Chronic Cyclic Heat Stress

Chronic heat stress can result in oxidative damage from increased reactive oxygen species. One proposed method to alleviate the chronic effects of HS is the supplementation of sulfur amino acids (SAA) which can be metabolized to glutathione, an important antioxidant. Therefore, the objective of this experiment was to determine the effects of dietary SAA content on broiler chickens exposed to HS from 28 to 35 d on broiler performance, body temperature, intestinal permeability, and oxidative status. Four experimental treatments were arranged as a 2 × 2 factorial consisting of HS (6 h at 33.3°C followed by 18 h at 27.8°C from 28 to 35 d of age) and Thermoneutral (TN- 22.2°C continuously from 28 to 35 d) and 2 dietary concentrations of SAA formulated at 100% (0.95, 0.87, and 0.80% for starter, grower, and finisher diets) or 130% SAA (1.24, 1.13, and 1.04% for starter, grower, and finisher diets). A total of 648-day-old, male Ross 708 chicks were placed in 36 pens with 18 chicks/pen and 9 replicates per treatment. Data were analyzed as a 2 × 2 factorial in JMP 14 (P ≤ 0.05). No interaction effects were observed on broiler live performance (P > 0.05). As expected, HS reduced BWG by 92 g and increased FCR by 11 points from 28 to 35 d of age compared to TN, respectively (P ≤ 0.05). The supplementation of SAA had no effect on live performance (P > 0.05). Cloacal temperatures were increased by 1.7, 1.4, and 1.2°C with HS at 28, 31, and 35 d compared to TN, respectively (P ≤ 0.05) and dietary SAA did not alter cloacal temperatures. At 28 d of age, supplementation of SAA to birds exposed to HS interacted as serum FITC-dextran (an indicator of intestinal permeability) was reduced to that of the TN group (P ≤ 0.05). The interaction was lost at 31 d, but HS still increased intestinal permeability (P ≤ 0.05). By 35 d, broilers were able to adapt to the HS conditions and intestinal permeability was unaffected (P > 0.05). Potential oxidative damage was reduced by increased SAA supplementation as indicated by an improvement in the reduced glutathione to oxidized glutathione ratio of 5 and 45 % at 28 (P = 0.08) and 35 d (P ≤ 0.05). These data suggest that intestinal permeability is compromised initially and to at least three d of heat exposure before the bird can adjust. However, oxidative damage in the liver of broilers exposed to HS is more chronic, building over the entire 7 d HS period and increased dietary SAA might have some protective effects on both broiler intestinal permeability and oxidative stress responses to HS.

Integrated analysis of fish intestine biomarkers: Complementary tools for pollution assessment

The gastrointestinal tract and its enteric nervous system are the first routes of food and xenobiotics uptake. Considering the importance of this organ, this study evaluated intestinal biomarkers of Sphoeroides testudineus integrating the data to generate tools for pollution assessment. The fish were collected in three sites of São Paulo Coast and their intestines were analyzed for biochemical, histology, and neuronal density and morphometry biomarkers. To evaluate the differences among the data, a PERMANOVA was applied, followed by a FA/PCA. The PERMANOVA indicated differences (P < 0.001) between the regions (RA, A1, and A2). Four factors were extracted from the FA/PCA (62% cumulative), showing that the animals from A2 presented severe alterations, mainly in intestinal morphometry and neuronal density. A1 alterations refer mainly to the increase of neuronal metabolism. Our results also evidence a gradient of environmental quality related to the protection level (AR > A1 > A2).

RNA-seq analysis of gene expression profiles in posttraumatic stress disorder, Parkinson's disease and schizophrenia identifies roles for common and distinct biological pathways

Evidence suggests that shared pathophysiological mechanisms in neuropsychiatric disorders (NPDs) may contribute to risk and resilience. We used single-gene and network-level transcriptomic approaches to investigate shared and disorder-specific processes underlying posttraumatic stress disorder (PTSD), Parkinson's disease (PD) and schizophrenia in a South African sample. RNA-seq was performed on blood obtained from cases and controls from each cohort. Gene expression and weighted gene correlation network analyses (WGCNA) were performed using DESeq2 and CEMiTool, respectively. Significant differences in gene expression were limited to the PTSD cohort. However, WGCNA implicated, amongst others, ribosomal expression, inflammation and ubiquitination as key players in the NPDs under investigation. Differential expression in ribosomal-related pathways was observed in the PTSD and PD cohorts, and focal adhesion and extracellular matrix pathways were implicated in PD and schizophrenia. We propose that, despite different phenotypic presentations, core transdiagnostic mechanisms may play important roles in the molecular aetiology of NPDs.

Effects of N-Acetyl Cysteine on Genes Expression of c-myc, and Ask-1, Histopathological, Oxidative Stress, Inflammation, and Apoptosis in the Liver of Male Rats Exposed to Cadmium

This study aimed to consider the oxidative damage induced by cadmium (Cd) and apoptosis and the role of N-acetylcysteine (NAC) in preserving hepatic cells against Cd toxicity. Male rats were randomly divided into seven groups including G1 (control), G2 (single dose of Cd), G3 (continuous dose of Cd), G4 (single dose of Cd + continuous dose of NAC), and G5 (continuous dose of Cd + continuous dose of NAC). Hepatic cells apoptosis was measured using TUNEL assay method. Levels of malondialdehyde (MDA), TNF-α, IL-10, and total antioxidant capacity (TAC) were measured by specific kits. Expression of c-myc and Ask-1 genes was considered using RT-PCR. NAC treatments significantly improved TAC and IL-10, but decreased MDA and TNF-α values in rats that were exposed to a single and continuous dose of Cd (p < 0.05). Exposure to a single and continuous dose of Cd caused a significant increase in c-myc expression by 3.76-fold (p < 0.001) and 8.17-fold (p < 0.0001), respectively. Single and continuous dose treatment of Cd led to a significant increase in Ask1 expression by 4.38-fold (p < 0.001) and 13.52-fold (p < 0.001), respectively. NAC treatments significantly decreased the expression of c-myc, and Ask-1 in rats exposed to single or continuous Cd. Cd exposure is strongly associated with oxidative stress, inflammation, antioxidant depletion, and liver cells apoptosis. NAC can protect liver tissue against Cd by elevating antioxidants capacity, mitigating oxidative stress and inflammation, as well as down-regulating of apoptotic genes.

Biomarkers of Oxidative Stress and Antioxidant Defense

A number of reactive oxygen and nitrogen species are produced during normal metabolism in human body. These species can be both radical and non-radical and have varying degrees of reactivity. Although they have some important functions in the human body, such as contributing to signal transmission and the immune system, their presence must be balanced by the antioxidant defense system. The human body has an excellent intrinsic enzymatic antioxidant system in addition to different non-enzymatic antioxidants having small molecular masses. An extrinsic source of antioxidants are foodstuffs such as fruits, vegetables, herbs and spices, mostly rich in polyphenols. When the delicate biochemical balance between oxidants and antioxidants is disturbed in favor of oxidants, "oxidative stress" conditions emerge, under which reactive species can cause oxidative damage to biomacromolecules such as proteins, carbohydrates, lipids and DNA. This oxidative damage is often associated with cancer, aging, and neurodegenerative disorders. Because reactive species are extremely short-lived, it is almost impossible to measure their concentrations directly. Although there are certain methods such as ESR / EPR that serve this purpose, they have some disadvantages and are quite costly systems. Therefore, products generated from oxidative damage of proteins, lipids and DNA are often used to quantify the extent of oxidative damage rather than direct measurement of reactive species. These oxidative damage products are usually known as biomarkers. Determination of the concentrations of these biomarkers and changes in the concentration of protective antioxidants can provide useful information for avoiding certain diseases and keep healthy conditions.

N-Acetyl cysteine mitigates histopathological changes and inflammatory genes expressions in the liver of cadmium exposed rats

This study aimed to consider the expression of Nrf2, NLRP3 and caspase 1 genes, as well as oxidative stress, and the protective role of N-acetyl cysteine (NAC) in the liver of rats treated with cadmium (Cd). Male rats were randomly divided into five groups including G1 (control), G2 (single dose of Cd), G3 (continuous dose of Cd), G4 (single dose of Cd + NAC), and G5 (continuous dose of Cd + NAC). Levels of malondialdehyde (MDA) and total antioxidant capacity (TAC) were measured. Expression of Nrf2, NLRP3 and caspase 1 genes was considered using RT-PCR. NAC treatments significantly improved TAC, but decreased MDA values in rats that exposed to continuous dose of Cd (p<0.05). Exposure to continuous dose of Cd caused a significant decrease in Nrf2 expression by 2.46-fold (p<0.001), but enhanced expression of NLRP3 and Caspase 1 genes by 3.13-fold and 3.16-fold), respectively (p<0.001). Compared to rats that treated to continuous dose of Cd, NAC supplementation enhanced the expression of Nrf2 by 1.67-fold (p<0.001) and reduced the expression of NLRP3 and Caspase 1 genes by 1.39-fold (p<0.001) and 1.58-fold (p<0.001), respectively. Down-regulation of Nrf2 and overexpression of NLRP3 and caspase 1 seems to be one of the main mechanisms of Cd toxicity on liver tissue. NAC protects liver tissue against Cd-induced oxidative injuries via enhancement of Nrf2 expression and reduction of NLRP3 and caspase 1 genes.

Biochemical Evaluation of the Effects of Hydroxyurea in Vitro on Red Blood Cells

Hydroxyurea (HU) is a low-cost, low-toxicity drug that is often used in diseases, such as sickle cell anemia and different types of cancer. Its effects on the red blood cells (RBC) are still not fully understood. The in vitro effects of HU were evaluated on the biochemical parameters of the RBC from healthy individuals that were treated with 0.6 mM or 0.8 mM HU for 30 min and 1 h. After 30 min, there was a significant increase in almost all of the parameters analyzed in the two concentrations of HU, except for the pyruvate kinase (PK) activity. A treatment with 0.8 mM HU for 1 h resulted in a reduction of the levels of lipid peroxidation, Fe³⁺, and in the activities of some of the enzymes, such as glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), and PK. After the incubation for 1 h, the levels of H₂O₂, lipid peroxidation, reduced glutathione (GSH), enzymatic activity (hexokinase, G6PD, and superoxide dismutase (SOD) were reduced with the treatment of 0.8 mM HU when compared with 0.6 mM. The results have suggested that a treatment with HU at a concentration of 0.8 mM seemed to be more efficient in protecting against the free radicals, as well as in treating diseases, such as sickle cell anemia. HU appears to preferentially stimulate the pentose pathway over the glycolytic pathway. Although this study was carried out with the RBC from healthy individuals, the changes described in this study may help to elucidate the mechanisms of action of HU when administered for therapeutic purposes.

Transcriptional Profiling of Aflatoxin B1-Induced Oxidative Stress and Inflammatory Response in Macrophages

Aflatoxin B1 (AFB1) is a highly toxic mycotoxin that causes severe suppression of the immune system of humans and animals, as well as enhances reactive oxygen species (ROS) formation, causing oxidative damage. However, the mechanisms underlying the ROS formation and immunotoxicity of AFB1 are poorly understood. This study used the mouse macrophage RAW264.7 cell line and whole-transcriptome sequencing (RNA-Seq) technology to address this knowledge-gap. The results show that AFB1 induced the decrease of cell viability in a dose- and time-dependent manner. AFB1 also significantly increased intracellular productions of ROS and malondialdehyde and decreased glutathione levels. These changes correlated with increased mRNA expression of NOS2, TNF-α and CXCL2 and decreased expression of CD86. In total, 783 differentially expressed genes (DEGs) were identified via RNA-Seq technology. KEGG analysis of the oxidative phosphorylation pathway revealed that mRNA levels of ND1, ND2, ND3, ND4, ND4L, ND5, ND6, Cyt b, COX2, ATPeF0A and ATPeF08 were higher in AFB1-treated cells than control cells, whereas 14 DEGs were downregulated in the AFB1 group. Furthermore, seven immune regulatory pathways mediated by oxidative stress were identified by KEGG analysis. Altogether, these data suggest that AFB1 induces oxidative stress in macrophages via affecting the respiratory chain, which leads to the activation of several signaling pathways related to the inflammatory response.

Omega-3 fats in pregnancy: could a targeted approach lead to better metabolic health for children?

The prevalence of childhood obesity is increasing worldwide, and the children of women who are obese during pregnancy are at greatest risk. This risk may be mediated by exaggeration of the normal insulin resistance of pregnancy. Omega-3 (n-3) fats are insulin sensitizing. Supplementation during pregnancy may reduce metabolic risk and adiposity in the children. Though results from animal studies are encouraging, completed clinical trials have not demonstrated this benefit. However, to our knowledge, previous studies have not targeted women who are overweight or obese while pregnant-the group at greatest risk for insulin resistance and most likely to benefit from n-3. In this narrative review, the importance of performing clinical trials restricted to women who are overweight or obese is discussed, as is the potential importance of n-3 dose, oil source and quality, and the timing of the intervention.

Targeting programmed cell death in metabolic dysfunction-associated fatty liver disease (MAFLD): a promising new therapy

Most currently recommended therapies for metabolic dysfunction-associated fatty liver disease (MAFLD) involve diet control and exercise therapy. We searched PubMed and compiled the most recent research into possible forms of programmed cell death in MAFLD, including apoptosis, necroptosis, autophagy, pyroptosis and ferroptosis. Here, we summarize the state of knowledge on the signaling mechanisms for each type and, based on their characteristics, discuss how they might be relevant in MAFLD-related pathological mechanisms. Although significant challenges exist in the translation of fundamental science into clinical therapy, this review should provide a theoretical basis for innovative MAFLD clinical treatment plans that target programmed cell death.

Baltetin: a new C-type lectin-like isolated from Bothrops alternatus snake venom which act as a platelet aggregation inhibiting

C-type lectin-like proteins found in snake venom, known as snaclecs, have important effects on hemostasis through targeting membrane receptors, coagulation factors and other hemostatic proteins. Here, we present the isolation and functional characterization of a snaclec isolated from Bothrops alternatus venom, designated as Baltetin. We purified the protein in three chromatographic steps (anion-exchange, affinity and reversed-phase chromatography). Baltetin is a dimeric snaclec that is approximately 15 and 25 kDa under reducing and non-reducing conditions, respectively, as estimated by SDS-PAGE. Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry and Edman degradation sequencing revealed that Baltetin is a heterodimer. The first 40 amino acid residues of the N-terminal region of Baltetin subunits share a high degree of sequence identity with other snaclecs. Baltetin had a specific, dose-dependent inhibitory effect on epinephrine-induced platelet aggregation in human platelet-rich plasma, inhibiting up to 69% of platelet aggregation. Analysis of the infrared spectra suggested that the interaction between Baltetin and platelets can be attributed to the formation of hydrogen bonds between the PO32- groups in the protein and PO2- groups in the platelet membrane. This interaction may lead to membrane lipid peroxidation, which prevents epinephrine from binding to its receptor. The present work suggests that Baltetin, a new C-type lectin-like protein isolated from B. alternatus venom, is the first snaclec to inhibit epinephrine-induced platelet aggregation. This could be of medical interest as a new tool for the development of novel therapeutic agents for the prevention and treatment of thrombotic disorders.

The effect of N-Acetyl cysteine on the expression of Fxr (Nr1h4), LXRα (Nr1h3) and Sirt1 genes, oxidative stress, and apoptosis in the liver of rats exposed to different doses of cadmium

The aim of this study was to consider the expression of farnesoid X receptor (Fxr), liver X receptor (LXRα) and sirtuin 1 (Sirt1), oxidative stress, inflammation, apoptosis, and the protective role of N-acetylcysteine (NAC) in the liver of rats treated with cadmium (Cd). 30 Wistar rats were divided into 5 groups: G1 (control), G2 (single dose of Cd), G3 (continuous dose of Cd), G4 (single dose of Cd + continuous dose of NAC), and G5 (continuous dose of Cd + continuous dose of NAC). The apoptosis of hepatic cells was measured using the TUNEL assay. Levels of malondialdehyde (MDA), IL-10, TNF-α, and total antioxidant capacity (TAC) were measured by specific kits. The expression of Fxr, LXRα, and Sirt1 genes and ratio of Bax/Bcl2 was considered using RT-PCR. While NAC treatment improved TAC and IL-10 values, it decreased MDA and TNF-α levels in the liver of rats exposed to Cd (P < 0.001). NAC decreased Bax/Bcl2 in the liver of G4 and G5 groups (P < 0.001). Exposure to a continuous dose of Cd decreased Fxr, LXRα, and Sirt1 expression by 36.65- (P < 0.001), 12.52- (P < 0.001) and 11.34-fold (P < 0.001) compared to control, respectively. NAC increased Fxr, LXRα, and Sirt1 expression (P < 0.01) and decreased Cd concentrations in both serum and tissue samples in G4 and G5 groups. Our results suggested that NAC protects liver tissue against Cd toxicity by elevating antioxidant capacity, mitigating oxidative stress, inflammation, apoptosis and up-regulation of FXR, LXR, and SIRT1 genes.

The effect of N-acetyl cysteine on oxidative stress and apoptosis in the liver tissue of rats exposed to cadmium

We considered the oxidative damage induced by cadmium (Cd) and apoptosis, and the role of N-acetylcysteine (NAC) in preserving cells against Cd toxicity in the liver of male rats. NAC significantly improved total antioxidant capacity (TAC) and decreased malondialdehyde (MDA) in rats exposed to single and continuous dose of Cd. Single and continuous exposure to Cd caused a significant increase in Bax expression (by 1.5-fold and 3.61-fold, respectively) and significant decrease in expression of Bcl2 compared to control (by 9.14-fold and 2.36-fold, respectively). The expression of Caspase 3 and 8 in rats exposed to Cd was significantly higher than control group (P < 0.05). NAC protects liver tissue against Cd by elevating antioxidants capacity, mitigating oxidative stress, as well as down-regulating of apoptotic factors.

Free-Radical-Initiated Phospholipid Oxidations at the Air-Water Interface: The Oxidation of Unsaturated and Saturated Fatty Acid Chains

Lipid oxidations initiated by free radicals are usually considered to undergo peroxidation, a chain process starting with hydrogen abstraction by an initiator, followed by O₂ uptake. While this peroxidation mechanism is widely accepted and sometimes taken for granted, here we provide evidence of the oxidation of both of the unsaturated and saturated fatty acid chains in phospholipids initiated by photoinitiator 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TMDPO) at the air-water interface, and no peroxidation products are observed in these reactions. A unique field-induced droplet ionization mass spectrometry (FIDI-MS) methodology which is capable of the selective online sampling of monolayers of molecules that reside at the air-water interface is employed to detect the products. We have shown that the double bonds on the oleyl chains of the lipids are first oxidized into epoxides, after which other saturated carbon atoms are oxidized into carbonyl groups. We anticipate that this work will draw more attention to the complexity of the lipid oxidation chemistry initiated by free radicals.

Fish oil supplements, oxidative status, and compliance behaviour: Regulatory challenges and opportunities

BACKGROUND

Fish oil supplements that are rich in omega-3 long-chain polyunsaturated fatty acids (n-3 PUFAs). PUFAs are among the most widely-used dietary supplements globally, and millions of people consume them regularly. There have always been public concerns that these products should be guaranteed to be safe and of good quality, especially as these types of fish oil supplements are extremely susceptible to oxidative degradation.

OBJECTIVES

The aim of the current study is to investigate and examine the oxidation status of dietary supplements containing fish oils and to identify important factors related to the oxidation status of such supplements available in the United Arab Emirates (UAE).

METHODS

A total of 44 fish oil supplements were analysed in this study. For each product, the oxidative parameters peroxide value (PV), anisidine value (AV), and total oxidation (TOTOX) were calculated, and comparisons were made with the guidelines supplied by the Global Organization for EPA and DHA Omega-3s (GOED). Median values for each of the above oxidative parameters were tested using the Kruskal-Wallis and Mann-Whitney U tests. P values < 0.05 were chosen as the statistically significant boundary.

RESULTS

The estimate for the average PV value was 6.4 with a 95% confidence interval (CI) [4.2-8.7] compared to the maximum allowable limit of 5 meq/kg. The estimate for the average P-AV was 11 with a 95% CI [7.8-14.2] compared to the maximum allowable limit of 20. The estimate for the average TOTOX value was 23.8 meq/kg with a 95% CI [17.4-30.3] compared to the maximum allowable limit of 26 according to the GOED standards.

CONCLUSION

This research shows that most, although not all, of the fish oil supplements tested are compliant with the GOED oxidative quality standards. Nevertheless, it is clear that there should be a high level of inspection and control regarding authenticity, purity, quality, and safety in the processes of production and supply of dietary supplements containing fish oils.

Adipose-derived mesenchymal stem cells ameliorate lung epithelial injury through mitigating of oxidative stress in mustard lung

Aim: We investigated potential efficacy of autologous adipose-derived mesenchymal stem cell (MSC) on oxidative stress (OS) and airway remodeling in patients with chronic mustard lung. Patients & methods: Ten patients received 100 × 106 cells every 20 days for 4 injections over a 2-month period. Results: A gradual improvement was observed for 6 min walk test scores, pulmonary function tests and respiratory quality after MSCs therapy. A significant decrease was found for the mean levels of Mucin-1 protein (KL-6; p = 0.022) and Clara cell protein 16 (CC16; p = 0.005). Antioxidants had a tendency to be higher after each injection. Conclusion: Our findings revealed that MSCs therapy can be safely used for improvement of lung injury and regeneration in these patients without adverse effects. Trial registration number: NCT02749448 (ClinicalTrials.gov).

Phytochemical Analysis, Antioxidant Activity, Antimicrobial Activity, and Cytotoxicity of Chaptalia nutans Leaves

Objective

This work was to evaluate the chemical constitution of the hydromethanolic (30/70 methanol-water) macerating extract obtained from the leaves of C. nutans, as well as to study the antioxidant, antimicrobial, cytotoxic, and genotoxic activity of the species. Materials and methods. Phytochemical screening, antioxidant activity (total phenolic, total flavonoid, condensed tannins content, DPPH radical, and FRAP), antibacterial activity (P. aeruginosa, B. cereus, E. epidermidis, E. coli, S. aureus, E. faecalis, P. mirabilis, Candida glabrata (clinical isolate), Candida tropicalis (clinical isolate), C. krusei (clinical isolate), and C. albicans (clinical isolate)), and oxidative stress parameters (TBARS, carbonyl protein, and DCFH) were analyzed according to the literature. Toxicity of C. nutans was evaluated using an alternative method, D. melanogaster, as well as a locomotor assay.

Results

The phytochemical screening test of methanolic leaves extract revealed the presence of alkaloids, coumarins, quaternary bases, phenolics, flavonoids, tannins, and free steroids. A quantitative phytochemical study indicated the total phenol (30.17 ± 1.44 mg/g), flavonoid (21.64 ± 0.66 mg/g), and condensed tannins (9.58 ± 0.99 mg/g). DPPH (345.41 ± 5.35 μg/mL) and FRAP (379.98 ± 39.25 μM FeSO4/mg sample) show to extract of C. nutans leaves an intermediate value, indicating moderate antioxidant activity of the extract. Antibacterial results revealed only a positive result (antimicrobial activity) for the hexane fraction which significantly inhibited the microorganisms E. epidermidis, C. tropicalis, C. glabrata, and C. krusei at a concentration of 1000 μg/mL. TBARS, carbonyl protein, and DCFH demonstrate that the extract has the ability to protect the cell from protein and lipid damage, as well as the inhibition of oxygen-derived radicals at the three concentrations tested: 0.1, 1, and 10 mg/mL. Regarding the toxicity of C. nutans extract against D. melanogaster, it was found that until the concentration of 15 mg/mL, the extract showed no toxicity and that the LC₅₀ obtained was 24 mg/mL. Results show that the C. nutans extract leaves used to prevent PQ damage were effective in reducing flies' mortality and improving locomotor capacity.

Conclusion

Our studies demonstrated for the first time that C. nutans crude leaf extract has high antioxidant capacity both in vitro and in vivo through different analysis techniques. These results make it possible to infer future applications in the pharmacological area, evidenced by the low toxicity observed in D. melanogatser, as well as the ability to neutralize different sources of RONS.

Integrative assessment of low-dose gamma radiation effects on Daphnia magna reproduction: Toxicity pathway assembly and AOP development

High energy gamma radiation is potentially hazardous to organisms, including aquatic invertebrates. Although extensively studied in a number of invertebrate species, knowledge on effects induced by gamma radiation is to a large extent limited to the induction of oxidative stress and DNA damage at the molecular/cellular level, or survival, growth and reproduction at the organismal level. As the knowledge of causal relationships between effects occurring at different levels of biological organization is scarce, the ability to provide mechanistic explanation for observed adverse effects is limited, and thus development of Adverse Outcome Pathways (AOPs) and larger scale implementation into next generation hazard and risk predictions is restricted. The present study was therefore conducted to assess the effects of high-energy gamma radiation from cobalt-60 across multiple levels of biological organization (i.e., molecular, cellular, tissue, organ and individual) and characterize the major toxicity pathways leading to impaired reproduction in the model freshwater crustacean Daphnia magna (water flea). Following gamma exposure, a number of bioassays were integrated to measure relevant toxicological endpoints such as gene expression, reactive oxygen species (ROS), lipid peroxidation (LPO), neutral lipid storage, adenosine triphosphate (ATP) content, apoptosis, ovary histology and reproduction. A non-monotonic pattern was consistently observed across the levels of biological organization, albeit with some variation at the lower end of the dose-rate scale, indicating a complex response to radiation doses. By integrating results from different bioassays, a novel pathway network describing the key toxicity pathways involved in the reproductive effects of gamma radiation were proposed, such as DNA damage-oocyte apoptosis pathway, LPO-ATP depletion pathway, calcium influx-endocrine disruption pathway and DNA hypermethylation pathway. Three novel AOPs were proposed for oxidative stressor-mediated excessive ROS formation leading to reproductive effect, and thus introducing the world's first AOPs for non-chemical stressors in aquatic invertebrates.

Puerarin protects against iron overload-induced retinal injury through regulation of iron-handling proteins

Excess iron content can build up in the retina and lead to iron-mediated retinal injury. An important isoflavone C-glucoside, puerarin, has been reported to be involved in retinal protection. In this experiment, we studied the effects and potential mechanisms of puerarin on retinal injury in vivo and in vitro. We found that puerarin reduced serum and retinal iron content, attenuated the pathophysiological changes and retinal iron deposition, and partially prevented the decrease of rhodopsin and retinal pigment epithelium-specific 65 kDa protein expression in retinas of iron-overload mice. Puerarin rescued the abnormal expression of iron-handling proteins in the mouse retina and suppressed the oxidative stress induced by iron overload, as evident from the enhanced activity of superoxide dismutase, catalase, and glutathione peroxidase and decreased content of malondialdehyde. Moreover, puerarin inhibited the phosphorylation of p38 and ERK mitogen-activated protein kinases (MAPKs) and signal transducer and activator of transcription 3 (STAT3), thereby protecting the retinal cells from apoptosis by suppressing cytochrome c release, caspase activation, and poly (ADP-ribose) polymerase cleavage in vivo. Also, the ability of puerarin to regulate iron-handling proteins, decrease intracellular Fe²⁺, and inhibit cell apoptosis was further confirmed in ARPE-19 cells. The experimental data verify the protective role of puerarin in the treatment of retinal injury caused by iron overload; its possible mechanisms might be associated with regulation of iron-handling proteins, enhancement of the antioxidant capacity, and the inhibition of MAPK and STAT3 activation and the apoptotic pathways under iron overload conditions.

Exploring the use of essential fatty acids in veterinary dermatology

BACKGROUND

The aim of the study was to discover the extent of use of essential fatty acids (EFAs) in veterinary practice, conditions used in, preparation of EFA supplement used and rationale for their use and to investigate the awareness of the oxidation of some commercial fish oil supplement preparations.

METHODS

A web-based questionnaire was distributed via email to a dermatology list server and posted to veterinary Facebook groups with questions relating to the use of EFAs, supplement choice, conditions used in, the level of importance of various factors regarding their use and awareness of their oxidation.

RESULTS

There were 309 responses from 32 countries. EFA supplements were used by 92.2 per cent of respondents. The most commonly used preparation of EFA supplementation was veterinary oral supplements (75.1 per cent), followed by veterinary diets (14.4 per cent), shop bought fish oil supplements (7.7 per cent), enhancing the diet with oily fish (2.5 per cent) and finally using a commercial pet food (0.3 per cent). Only 46.3 per cent of respondents who used them were aware of the oxidation of EFAs. Veterinary oral supplements were perceived to be the best preserved, followed by veterinary diets and lastly commercial fish oil supplements.

CONCLUSION

A large number of respondents advised the use of EFAs for veterinary dermatological conditions but less than 50 per cent were aware of the potential for EFAs to oxidise.

On the magnetosensitivity of lipid peroxidation: two- versus three-radical dynamics

We present a theoretical analysis of the putative magnetosensitivity of lipid peroxidation. We focus on the widely accepted radical pair mechanism (RPM) and a recently suggested idea based on spin dynamics induced in three-radical systems by the mutual electron-electron dipolar coupling (D3M). We show that, contrary to claims in the literature, lipid peroxides, the dominant chain carriers of the autoxidation process, have associated non-zero hyperfine coupling interactions. This suggests that their recombination could, in principle, be magnetosensitive due to the RPM. While the RPM indeed goes a long way to explaining magnetosensitivity in these systems, we show that the simultaneous interaction of three peroxyl radicals via the D3M can achieve larger magnetic field effects (MFE), even if the third radical is remote from the recombining radical pair. For randomly oriented three-radical systems, the D3M induces a low-field effect comparable to that of the RPM. The mechanism furthermore immunizes the spin dynamics to the presence of large exchange coupling interactions in the recombining radical pair, thereby permitting much larger MFE at magnetic field intensities comparable to the geomagnetic field than would be expected for the RPM. Based on these characteristics, we suggest that the D3M could be particularly relevant for MFE at low fields, provided that the local radical concentration is sufficient to allow for three-spin radical correlations. Eventually, our observations suggest that MFEs could intricately depend on radical concentration and larger effects could ensue under conditions of oxidative stress.

Effects of thermally oxidized canola oil and tannic acid supplementation on nutrient digestibility and microbial metabolites in finishing pigs1

The present study investigated the effects of oxidized canola oil and tannic acid (TA) supplementation on nutrient digestibility and microbial metabolites in finishing pigs. Four experimental diets were formulated to include 5% of either fresh canola oil (0 mEq/kg of peroxide value) or oxidized canola oil (180 mEq/kg of peroxide value). An equal portion of each diet was supplemented with 0.1% TA. Eight pigs (initial body weight of 82.89 ± 2.26 kg) were surgically fitted with a T-cannula at the distal ileum. At the beginning of the experiments, all pigs were fed a nitrogen-free diet for 7 d. Then, they were assigned to 4 dietary treatments according to an incomplete replicated 4 × 3 Latin square design with 3 periods to give 6 replicates per treatment. Each experimental period lasted for 9 d, starting with a 5-d adaptation period followed by 2 consecutive 2-d periods for fecal (day 6 and day 7) and ileal digesta (day 8 and day 9) collection. The inclusion of oxidized oil reduced (P < 0.05) the standardized ileal digestibility (SID) of Pro and the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of NDF. Also, pigs fed the oxidized oil tended to have lower (P ≤ 0.10) lactate and ammonia-nitrogen concentrations in the ileum and lower (P ≤ 0.10) acetate and propionate concentrations in the feces than those fed the fresh oil. The supplementation of 0.1% TA reduced (P < 0.05) the AID of NDF and the ATTD of gross energy, crude protein, and NDF. Additionally, the TA-supplemented diet tended to have a lower (P ≤ 0.10) digestible energy content than the nonsupplemented diet. Pigs fed the TA-supplemented diet showed reduced (P < 0.05) AID and SID of His, Cys, and Pro compared with those fed the nonsupplemented diet. There were interactive effects (P < 0.05) of oxidized oil and TA supplementation on acetate, isovalerate, total short chain fatty acids, and pH level in the ileum. In conclusion, the results indicated that the effects of oxidized oil are greater on microbial activities rather than nutrient digestibility. Although negative effects of dietary TA supplementation were observed in relation to nutrient digestibility, TA supplementation was found to ameliorate these negative effects of oxidized oil on microbial metabolites. Therefore, further studies are required to investigate the interaction between dietary oxidized oil and TA in relation with the gut microbiota in pigs.

Peripheral Oxidative Stress Markers in Patients with Bipolar Disorder during Euthymia and in Siblings

AIMS

Oxidative stress is increased during the acute phases of bipolar disorder (BD). Our aim here was to analyze oxidative stress biomarkers in patients with BD during euthymia and their siblings.

METHOD

A cross-sectional study was performed in euthymic patients with BD-I (n=48), unaffected siblings (n=23) and genetically unrelated healthy controls (n=21). Protein carbonyl content (PCC), total antioxidant capacity (TRAP), lipid peroxidation (TBARS) and uric acid were measured as biomarkers of oxidative stress in blood.

RESULTS

The antioxidant capacity (TRAP) was lower (p<0.001) in patients with BD compared to their siblings and controls, whereas no differences were observed in PCC, TBARS or uric acid. In patients, the concentrations of TRAP and TBARS were positively associated with the dose of valproic acid (p<0.05 and p<0.001, respectively). The concentrations of these biomarkers were not significantly associated with any of socio-demographic and clinical variables.

CONCLUSION

A selective reduction in antioxidant capacity is present in BD during euthymia state, whereas other markers of oxidative stress are unaltered during euthymia. Siblings did not show any alterations in oxidative stress biomarkers. Oxidative stress might represent a state-dependent marker in BD. The association between treatment with valproic acid and oxidative stress markers in euthymia deserves further studies.

Comparative Efficacy of Synthetic and Natural Tenderizers on Quality Characteristics of Restructured Spent Hen Meat Slices (RSHS)

In the present study, comparative efficacy of natural as well as synthetic tenderizers on the quality characteristics of restructured spent hen meat slices (RSHS) was studied. Four different batches of RSHS viz. Control (without any tenderizer), T1 (1.25% calcium chloride replacing salt in formulation), T2 and T3 (1.5% each of pineapple rind and fig powder, replacing binder in the formulation) were developed in pre-standardized formulation. Vacuum tumbling was performed for 2.5 h and cooked product (RSHS) was assayed for quality attributes. Samples were packaged in aerobic conditions, stored for 21 days under refrigeration (4±1°C) and were evaluated for pH, oxidative and microbial quality parameters at regular interval of 7 days. Water holding capacity of T2 was recorded the highest and significantly higher (p<0.05) than all other samples. The textural attributes of T2 were comparable to T1 but significantly higher (p<0.05) than C and T3. The colour attributes (L*, a*, and b* value) of T2 and T3 were improved due to use of natural tenderizers. During sensory evaluation, tenderness scores for T2 samples were recorded the highest. Throughout storage period, thiobarbituric acid reactive substances (TBARS), free fatty acids (FFA) and peroxide value (PV) followed an increasing trend for control as well as treated products; however, T2 showed a significantly (p<0.05) lower value than control and other treated samples. It can be concluded that good quality RSHS with better storage stability could be prepared by utilizing 1.5% pineapple rind powder as natural tenderizer.

Heme oxygenase-1 induction by hemin prevents oxidative stress-induced acute cholestasis in the rat

We previously demonstrated in in vitro and ex vivo models that physiological concentrations of unconjugated bilirubin (BR) prevent oxidative stress (OS)-induced hepatocanalicular dysfunction and cholestasis. Here, we aimed to ascertain, in the whole rat, whether a similar cholestatic OS injury can be counteracted by heme oxygenase-1 (HO-1) induction that consequently elevates endogenous BR levels. This was achieved through the administration of hemin, an inducer of HO-1, the rate-limiting step in BR generation. We found that BR peaked between 6 and 8 h after hemin administration. During this time period, HO-1 induction fully prevented the pro-oxidant tert-butylhydroperoxide (tBuOOH)-induced drop in bile flow, and in the biliary excretion of bile salts and glutathione, the two main driving forces of bile flow; this was associated with preservation of the membrane localization of their respective canalicular transporters, bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2), which are otherwise endocytosed by OS. HO-1 induction counteracted the oxidation of intracellular proteins and membrane lipids induced by tBuOOH, and fully prevented the increase in the oxidized-to-total glutathione (GSHt) ratio, a sensitive parameter of hepatocellular OS. Compensatory elevations of the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) were also prevented. We conclude that in vivo HO-1 induction protects the liver from acute oxidative injury, thus preventing consequent cholestasis. This reveals an important role for the induction of HO-1 and the consequently elevated levels of BR in preserving biliary secretory function under OS conditions, thus representing a novel therapeutic tool to limit the cholestatic injury that bears an oxidative background.

The effects of Trolox on the quality of sperm from captive squirrel monkey during liquefaction in the extender ACP-118™

The aim of this study was to evaluate the effect of incubating semen for different periods (90, 270 or 450 min) with or without Trolox® (100 or 150 µM) on the quality of sperm from Saimiri collinsi. Sperm motility, vigour, and plasma membrane integrity (PMI) were evaluated in both fresh semen and semen incubated for different time periods, i.e. 90, 270 or 450 min of incubation. Supplementation of semen extender with Trolox® 100 µM improved sperm motility, vigour and PMI for up to 270 min of incubation.

Antioxidant Enzyme Activities in Rabbits Under Oxidative Stress Induced By High Fat Diet

INTRODUCTION

The aim of this study was to investigate whether the type and form of oil (raw/non-oxidised (N) or post-frying/oxidised (O)) consumed in high-fat diets affect the oxidative status of an organism, as observed by malondialdehyde (MDA) concentration as an oxidative factor and antioxidant enzyme activity.

MATERIAL AND METHODS

Fats in the diet came from rapeseed oil (R) and olive oil (O).

RESULTS

The applied diet caused a decrease in MDA concentration (μmol/L) in serum in group RN from 2.94 ± 0.87 to 1.76 ± 0.13, in group ON from 2.45 ± 0.62 to 1.50 ± 0.10, and in group OO from 2.70 ± 1.16 to 1.84 ± 0.36. Meanwhile, MDA concentration (mmol/L) increased in blood haemolysate in group RO from 0.15 ± 0.07 to 0.22 ± 0.03 and in group OO from 0.17 ± 0.02 to 0.22 ± 0.02. The observed changes caused a response of the enzymatic antioxidant system in both models, especially followed by an increase in activities of total superoxide dismutase and its mitochondrial isoenzyme in all experimental groups, while its cytosolic isoenzyme activity increased only in ON and OO groups. Increased activity of glutathione peroxidase (GPX) in groups RN and RO and of catalase (CAT) in groups ON and OO was observed. Significant differences in responses to the different types and forms of oils were probably caused by the different oxidative stability of the studied oils.

CONCLUSION

This diet disturbed the body's oxidative status; however, during the six-month study the enzymatic antioxidant system remained effective.

The hepcidin-ferroportin axis controls the iron content of Salmonella-containing vacuoles in macrophages

Macrophages release iron into the bloodstream via a membrane-bound iron export protein, ferroportin (FPN). The hepatic iron-regulatory hormone hepcidin controls FPN internalization and degradation in response to bacterial infection. Salmonella typhimurium can invade macrophages and proliferate in the Salmonella-containing vacuole (SCV). Hepcidin is reported to increase the mortality of Salmonella-infected animals by increasing the bacterial load in macrophages. Here we assess the iron levels and find that hepcidin increases iron content in the cytosol but decreases it in the SCV through FPN on the SCV membrane. Loss-of-FPN from the SCV via the action of hepcidin impairs the generation of bactericidal reactive oxygen species (ROS) as the iron content decreases. We conclude that FPN is required to provide sufficient iron to the SCV, where iron serves as a cofactor for the generation of antimicrobial ROS rather than as a nutrient for Salmonella.

The effects of iron on vacuole-resident Salmonella in macrophages are unclear. Here the authors show that the bacteria are not subject to nutritional inhibition by iron deprivation, but that iron depletion in the vacuole, via the hepcidin-ferroportin axis, inhibits the bactericidal effect of oxidative burst.

Sulfur mustard triggers oxidative stress through glutathione depletion and altered expression of glutathione-related enzymes in human airways

CONTEXT

Sulfur mustard (SM) is a lipophilic and reactive chemical compound that targets human airway system.

OBJECTIVE

Glutathione (GSH) depletion, oxidative stress (OS) status, and changes in expression of GSH-dependent antioxidant enzymes were considered in human mustard lungs.

MATERIALS AND METHODS

Lung biopsies and bronchoalveolar lavage (BAL) were collected from non-exposed (n = 10) individuals and SM-exposed patients (n = 12). Alterations in expression of GSH-dependent enzymes were studied using RT² Profiler™ PCR array. OS was evaluated by determining BAL fluid levels of total antioxidant capacity (TAC), malondialdehyde (MDA), and GSH.

RESULTS

Mean TAC (0.142 ± 0.027 µmol/l) and GSH (4.98 ± 1.02 nmol/l) in BAL fluids of control group was significantly higher (p < .05) than those in SM-exposed patients (TAC = 0.095 ± 0.018 µmol/l and GSH= 3.09 ± 1.02 nmol/l), while MDA level in BAL fluids of these patients (0.71 ± 0.06 nmol/l) was significantly (p = .001) higher than that in controls (0.49 ± 0.048 nmol/l). Glutathione peroxidases (GPXs), glutathione-s-transferases (GSTs), and glutathione synthetase (GSS) enzymes were overexpressed in mustard lung biopsies, while glutathione reductase (GSR) was significantly downregulated (14.95-fold).

CONCLUSIONS

GSH depletion induced by GSR downregulation may be a major mechanism of SM toxicity on human lung. Despite overexpression of GSTs and GPXs genes, GSH depletion may decline the productivity of these enzymes and total antioxidants capacity, which is associated with OS.