Cellular Lipid Peroxidation Research Articles

In vivo protective effect of late embryogenesis abundant protein (ApSK3 dehydrin) on Agapanthus praecox to promote post-cryopreservation survival

Dehydrins (DHNs), as members of the late embryogenesis abundant protein family, play critical roles in the protection of seeds from dehydration and plant adaptation to multiple abiotic stresses. Vitrification is a basic method in plant cryopreservation and is characterized by forming a glassy state to prevent lethal ice crystals produced during cryogenic storage. In this study, ApSK3 type DHN was genetically transformed into embryogenic calluses (EC) of Agapanthus praecox by overexpression (OE) and RNA interference (RNAi) techniques to evaluate the in vivo protective effect of DHNs during cryopreservation. The cell viability showed a completely opposite trend in OE and RNAi cell lines, the cell relative death ratio was decreased by 20.0% in ApSK3-OE EC and significantly increased by 66.15% in ApSK3-RNAi cells after cryopreservation. Overexpression of ApSK3 increased the content of non-enzymatic antioxidants (AsA and GSH) and up-regulated the expression of CAT, SOD, POD, and GPX genes, while ApSK3-RNAi cells decreased antioxidant enzyme activities and FeSOD, POD, and APX genes expression during cryopreservation. These findings suggest that ApSK3 affects ROS metabolism through chelating metal ions (Cu2+ and Fe3+), alleviates H2O2 and OH· excessive generation, activates the antioxidant system, and improves cellular REDOX balance and membrane lipid peroxidation damage of plant cells during cryopreservation. DHNs can effectively improve cell stress tolerance and have great potential for in vivo or in vitro applications in plant cryopreservation.

Iron-mediated epigenetic activation of NRF2 targets

The toxic effects of excess dietary iron within the colonic lumen are well documented, particularly in the context of Inflammatory Bowel Disease (IBD) and Colorectal Cancer (CRC). Proposed mechanisms that underpin iron-associated intestinal disease include: (1) the pro-inflammatory and ROS-promoting nature of iron, (2) gene-expression alterations, and (3) intestinal microbial dysbiosis. However, to date no studies have examined the effect of iron on the colonic epigenome. Here we demonstrate that chronic iron exposure of colonocytes leads to significant hypomethylation of the epigenome. Bioinformatic analysis highlights a significant epigenetic effect on NRF2 (nuclear factor erythroid 2-related factor 2) pathway targets (including NAD(P)H Quinone Dehydrogenase 1 [NQO1] and Glutathione peroxidase 2 [GPX2]); this demethylating effect was validated and subsequent gene and protein expression quantified. These epigenetic modifications were not observed upon the diminishment of cellular lipid peroxidation with endogenous glutathione and the subsequent removal of iron. Additionally, the induction of TET1 expression was found post-iron treatment, highlighting the possibility of an oxidative-stress induction of TET1 and subsequent hypomethylation of NRF2 targets. In addition, a strong time dependence on the establishment of iron-orchestrated hypomethylation was found which was concurrent with the increase in the intracellular labile iron pool (LIP) and lipid peroxidation levels. These epigenetic changes were further validated in murine intestinal mucosa in models administered a chronic iron diet, providing evidence for the likelihood of dietary-iron mediated epigenetic alterations in vivo. Furthermore, significant correlations were found between NQO1 and GPX2 demethylation and human intestinal tissue iron-status, thus suggesting that these iron-mediated epigenetic modifications are likely in iron-replete enterocytes. Together, these data describe a novel mechanism by which excess dietary iron is able to alter the intestinal phenotype, which could have implications in iron-mediated intestinal disease and the regulation of ferroptosis.

Ferrostatin-1-loaded liposome for treatment of corneal alkali burn via targeting ferroptosis.

Alkali burn is a potentially blinding corneal injury. During the progression of alkali burn‐induced injury, overwhelmed oxidative stress in the cornea triggers cell damage, including oxidative changes in cellular macromolecules and lipid peroxidation in membranes, leading to impaired corneal transparency, decreased vision, or even blindness. In this study, we identified that ferroptosis, a type of lipid peroxidation‐dependent cell death, mediated alkali burn‐induced corneal injury. Ferroptosis‐targeting therapy protected the cornea from cell damage and neovascularization. However, the specific ferroptosis inhibitor ferrostatin‐1 (Fer‐1) is hydrophobic and cannot be directly applied in the clinic. Therefore, we developed Fer‐1‐loaded liposomes (Fer‐1‐NPs) to improve the bioavailability of Fer‐1. Our study demonstrated that Fer‐1‐NPs exerted remarkable curative effects regarding corneal opacity and neovascularization in vivo. The efficacy was comparable to that of dexamethasone, but without appreciable side effects. The significant suppression of ferroptosis (induced by lipid peroxidation and mitochondria disruption), inflammation, and neovascularization might be the mechanisms underlying the therapeutic effect of Fer‐1‐NPs. Moreover, the Fer‐1‐NPs treatment showed no signs of cytotoxicity, hematologic toxicity, or visceral organ damage, which further confirmed the biocompatibility. Overall, Fer‐1‐NPs provide a new prospect for safe and effective therapy for corneal alkali burn.

Mannose Metabolism Is a Metabolic Vulnerability Unveiled By Standard and Novel Therapies in Acute Myeloid Leukemia

IntroductionThe development of resistance to standard and novel therapies remains the main obstacle to cure in acute myeloid leukemia (AML). Metabolic rewiring has emerged as a therapeutically actionable vulnerability in AML, where specific metabolic adaptations arising as a result of driver mutations or in response to therapy have been reported. Mannose phosphoisomerase (MPI) is the first enzyme in the mannose metabolism (MM) pathway, that leads to the production of GDP-Mannose, a key sugar donor for N-glycosylation reactions. MPI was amongst the top drop-out genes in our published CRISPR-Cas9 screen aiming to identify sensitizers to FLT3 tyrosine kinase inhibitors (TKI) in AML carrying activating FLT3 internal tandem duplication (ITD) mutations (Gallipoli et al., Blood 2018). Moreover, analysis of published genomic datasets indicates that MPI expression levels are higher in AML compared to normal samples, correlate with patient outcome (A) and further increase in paired relapsed to diagnosis samples. We therefore hypothesized that MM and MPI inhibition sensitize AML cells to both FLT3-TKI and standard chemotherapy and tested this in preclinical models.MethodsExperiments were performed in human AML cell lines, primary AML mononuclear cells and normal CD34 + stem/progenitor cells. Liquid chromatography coupled to mass spectrometry and oxygen consumption/extracellular acidification rate as measured by a Seahorse analyser were employed to assess metabolic changes. Gene-expression was measured by RNA-sequencing and confirmed by RT-qPCR. Viability, surface protein expression and lipid peroxidation were assessed by flow-cytometry. Protein expression and localisation was measured by western blot and immunofluorescence. Gene silencing was performed using CRISPR-Cas9 gene editing and inducible short hairpin RNA interference.ResultsWe show that genetic and chemical MPI inhibition sensitizes FLT3 WT and FLT3 ITD AML cell lines in vitro to standard cytarabine chemotherapy and FLT3-TKI respectively and these effects are rescued by the addition of MPI downstream product mannose. We validate these findings in vivo using MPI knock-out (KO) cell line xenografts and in vitro using primary AML samples following MPI knock-down (B). We also demonstrate a lack of toxicity to normal CD34 + cells.Surprisingly, global metabolomic analysis show that MPI KO cells accumulate fatty acids and particularly polyunsaturated fatty acids (PUFA) (C), due to both increased uptake and reduced fatty acid oxidation (FAO). MPI KO cells downregulate several FAO metabolism genes and this is corroborated by the strong positive correlation of MPI expression levels with multiple genes involved in FAO across multiple primary AML datasets. Metabolic profiling demonstrates that MPI KO cells have reduced oxidative phosphorylation metabolism and in particular are unable to oxidise palmitate, an effect rescued by mannose or the FAO activator fenofibrate (D).We link this metabolic defect to the specific activation of the ATF6 arm of the unfolded protein response (UPR) due to a reduction in protein glycosylation in MPI KO cells. We validate this by demonstrating that activating or inhibiting ATF6 respectively phenocopies or rescues the effects of MPI KO (E) and show this to be secondary to ATF6 driving FAO inhibition, via transcriptional downregulation of PPARα, a master regulator of lipid catabolism.Finally, we show that accumulation of PUFA in MPI KO cells is accompanied by reduced cysteine levels and increased markers of oxidative stress and lipid peroxidation, such as 4-hydroxynonenal (4-HNE), all features associated with ferroptosis (F). We validate this by showing that combining FLT3-TKI with MPI KO leads to ferroptotic cell death in AML cells, which can be rescued by the radical-trapping antioxidant ferrostatin.ConclusionsWe provide further evidence to support the role of metabolic rewiring in driving therapy resistance in AML and show for the first time that targeting MPI and MM sensitizes AML cells to cytarabine and FLT3-TKI. Mechanistically we unveil a novel connection between MM and fatty acid metabolism, via activation of the ATF6 arm of the UPR, leading to cellular PUFA accumulation, lipid peroxidation and ferroptotic cell death. Finally, our findings also suggest that triggering ferroptosis can be leveraged as a therapeutically actionable mechanism driving cell death in therapy-resistant AML cells. [Display omitted] DisclosuresVassiliou: Kymab Ltd: Divested equity in a private or publicly-traded company in the past 24 months; STRM.BIO: Consultancy; Astrazeneca: Consultancy.

Genotoxicity of Momordica cymbalaria on Bone marrow cells of Swiss Albino mice

Genotoxicity is described as the property of the agent to cause changes in the genetic material leading to damage in the genetic information, such agents are called as genotoxins. This property is much seen in drugs that are used in the treatment of cancer. Cyclophosphamide is an anticancer drug that lead to gene toxicity through formation of its metabolites and generation of reactive oxygen species and free radicals that damage the genetic material. The main objectives of this research is to evaluate the effect of Momordica cymbalaria (10mg/kg and 50mg/ kg) on cyclophosphamide induced genotoxicity and also to study the genotoxic effect of Momordica cymbalaria (50mg/kg) without Cyclophosphamide treatment. The dose selection was made based on previous acute toxicity report. Animals were treated with Momordica cymbalaria and bone marrow cells were been isolated to observe the effect of drugs on the chromosomes and cellular division through chromosomal aberration assay and micronuclei assay respectively. Effect of drugs on the anti-oxidant enzymes such as glutathione and cellular lipid peroxidation was studied using the liver homogenate. The test drug Momordica cymbalaria showed significant genoprotective effect in dose dependent manner against the chromosomal aberrations and micronuclei formation induced by Cyclophosphamide. And also there was significant inhibition of lipid peroxidation and rise in GSH levels indicating the anti-oxidant property of the test drugs. The drugs Momordica cymbalaria has significant gene protecting effect in cells from Cyclophosphamide induced genotoxicity

Silica Nanoparticles as a Probable Anti-Oomycete Compound Against Downy Mildew, and Yield and Quality Enhancer in Grapevines: Field Evaluation, Molecular, Physiological, Ultrastructural, and Toxicity Investigations.

Downy mildew is the most destructive disease of grapevines in the regions of relatively warm and humid climate causing up to 50% yield losses. Application of silicon- (Si-) based products have been extensively studied against various oomycete, fungal, bacterial, and viral plant diseases, but studies on Si application in their nanosize are limited. In this study, the field application of silica nanoparticles (SiNPs) on Thompson Seedless grapevines (H4 strain) infected with downy mildew was evaluated. In addition, molecular, physiological, ultrastructural, and toxicity investigations were also conducted. The obtained results revealed that spraying of grapevines with SiNPs at 150 ppm significantly overexpressed the transcription factor jasmonate and ethylene-responsive factor 3 recording 8.7-fold, and the defense-related genes β-1,3-glucanase (11-fold), peroxidase (10.7-fold) pathogenesis-related-protein 1 (10.6-fold), and chitinase (6.5-fold). Moreover, a reduction up to 81.5% in the disease severity was achieved in response to this treatment. Shoot length and yield per grapevine were considerably enhanced recording up to 26.3 and 23.7% increase, respectively. The berries quality was also improved. Furthermore, this treatment led to an enhancement in the photosynthetic pigments, induction of phenolic and ascorbic acid contents, an increase in the activity of peroxidase and polyphenol oxidase enzymes, and a reduction in the cellular electrolyte leakage, lipid peroxidation, and H2O2 content. Scanning electron microscopy observations showed an increase up to 86.6% in the number of closed stomata and a reduction up to 55% in the average stomatal pore area in response to this treatment. Observations of the transmission electron microscopy showed ultrastructural alterations in the cells of a grapevine leaf due to the infection with downy mildew, including plasmolysis and disruption of the cellular components, abnormal chloroplasts, and thickening of the cell wall and cell membrane. These abnormal alterations were reduced in response to SiNPs spray. In contrast, this study also showed that this treatment had considerable cytotoxic and genotoxic effects at this direct dose/concentration. So, additional investigations to determine the SiNPs residue in the produced edible plant parts are urgently needed. In addition, the pre-harvest interval, toxicity index, and risk assessment should be evaluated before any recommendation for use.

Acyl Peptide Enzyme Hydrolase (APEH) activity is inhibited by lipid metabolites and peroxidation products

Acyl Peptide Enzyme Hydrolase (APEH) activity is decreased in certain diseases but the mechanism and impact behind this loss in activity is not well understood. We hypothesized that lipid metabolites and lipid peroxidation products produced in inflammatory diseases may bind to and inhibit APEH activity. In vitro studies carried out in mammalian cell lysates, as well as with purified APEH protein, support our hypothesis that cellular lipid metabolites and lipid peroxidation products significantly decrease APEH activity. Enzymatic assays and molecular docking in silico analysis suggest that larger lipid metabolites are the best APEH inhibitors. APEH activity was measured in vivo in mice exposed to chronic e-cigarette vapor, as e-cigarettes are known to increase reactive oxygen species and lipid peroxidation products. In support of our in vitro findings, APEH activity in our mouse model demonstrates decreased APEH activity in the brains of mice exposed to e-cigarette vapor. These results provide a novel mechanism by which APEH activity may be inhibited in disease states. Furthermore, APEH inhibition may contribute to disease development and progression in pathologies associated with redox imbalances and can potentially act as biomarker for oxidative stress in disease.

Mevalonate kinase of Leishmania donovani protects parasite against oxidative stress by modulating ergosterol biosynthesis

Leishmaniasis comprises of a wide variety of diseases, caused by protozoan parasite belonging to the genus Leishmania. Leishmania parasites undergo different types of stress during their lifetime and have developed strategies to overcome this damage. Identifying the mechanistic approach used by the parasite in dealing with the stress is of immense importance for unfolding the survival strategy adopted by the parasite. Mevalonate kinase (MVK) is an important regulatory factor in the mevalonate pathway in both bacteria and eukaryotes. In this study, we explored the role of Leishmania donovani mevalonate kinase (LdMVK) in parasite survival under stress condition. Hydrogen peroxide (H2O2) and menadione, the two known oxidants were used to carry out the experiments. The MVK expression was found to be up regulated ∼2.1 fold and ∼2.3 fold under oxidative stress condition and under the effect of anti-Leishmania drug, AmBisome respectively. The cell viability declined under the effect of MVK inhibitor viz: vanadyl sulfate (VS). The level of intracellular ROS was also found to be increased under the effect of MVK inhibitor. To confirm the findings, LdMVK over expression (LdMVK OE) and LdMVK knockdown (LdMVK KD) parasites were generated. The level of ergosterol, an important component of plasma membrane in L. donovani, was observed and found to be reduced by nearly 60 % in LdMVK KD parasite and increased by nearly 30 % in LdMVK OE parasites as compared to wild type. However, the ergosterol content was found to be elevated under oxidative stress. Furthermore, LdMVK was also found to be associated with maintaining the plasma membrane integrity and also in preventing the peroxidation of cellular lipids when exposed to oxidative stress.The above data clearly suggests that MVK has a vital role in protecting the parasite from oxidative stress. These findings may also explore the contribution of LdMVK in drug unresponsiveness which may help in future rational drug designing for leishmaniasis.

Molecular Mechanism Involved in Carotenoid Metabolism in Post-Smolt Atlantic Salmon: Astaxanthin Metabolism During Flesh Pigmentation and Its Antioxidant Properties

A better understanding of carotenoid dynamics (transport, absorption, metabolism, and deposition) is essential to develop a better strategy to improve astaxanthin (Ax) retention in muscle of Atlantic salmon. To achieve that, a comparison of post-smolt salmon with (+ Ax) or without (- Ax) dietary Ax supplementation was established based on a transcriptomic approach targeting pyloric, hepatic, and muscular tissues. Results in post-smolts showed that the pyloric caeca transcriptome is more sensitive to dietary Ax supplementation compared to the other tissues. Key genes sensitive to Ax supplementation could be identified, such as cd36 in pylorus, agr2 in liver, or fbp1 in muscle. The most modulated genes in pylorus were related to absorption but also metabolism of Ax. Additionally, genes linked to upstream regulation of the ferroptosis pathway were significantly modulated in liver, evoking the involvement of Ax as an antioxidant in this process. Finally, the muscle seemed to be less impacted by dietary Ax supplementation, except for genes related to actin remodelling and glucose homeostasis. In conclusion, the transcriptome data generated from this study showed that Ax dynamics in Atlantic salmon is characterized by a high metabolism during absorption at pyloric caeca level. In liver, a link with a potential of ferroptosis process appears likely via cellular lipid peroxidation. Our data provide insights into a better understanding of molecular mechanisms involved in dietary Ax supplementation, as well as its beneficial effects in preventing oxidative stress and related inflammation in muscle.

Cellular Total Lipid Peroxidation, and Glutathione S Transferase Levels in Larvae and Pupae of Aedes Aegypti with Catalysts Preparation of Mg-doped tio2 Nanoparticles.

Aim: synthesis, characterization, and application of modifying nanocomposite TiO2 doped with Magnesium for photodegradation of antioxidant system Larvae and Pupae of Aedes Aegypti Catalysts Preparation of Mg-doped TiO2 to determine activity of oxidative stress (MDA) and glutathione S Transferase, were known as a parameter of defense system resistance and immune maintained. This study was undertaken to assess the potential role of growth of stages of Aedes Aegypti correspondence with oxidant and antioxidant balance triggered by nanoparticle exposure. The amounts of these parameters in cellular samples were investigated using the following materials and procedures, intake 100 larvae and 100 pupae as subjects with (study subjects) and 3-9 days’ age-matched with healthy subjects as controls. at the second of the admission, as a marker of lipid peroxidation, and therefore an indicator of the activity of standard free radicals Nanoparticles Photo Catalysts, TiO2 doped with Mg, the standard prepared Nanopowder changes from the forbidden band TiO2 standard doping with atoms of Mg ،Mg) using the sol-gel method, for Mg-doped TiO2 nanoparticles, the estimated band gap energy is 2.92 eV. Tissue MDA was used to estimate thiobarbituric acid reactive substances (TBARS), and liquid glutathione reductase activity was assessed using Goldberg DM’s method. Results: When compared to controls, there was a dramatic rise in MDA content and glutathione s transferase efficiency in larvae and pupae populations exposed to photo catalyst modified nanoparticles. Conclusion: Increased MDA support to oxidative stress in larvae and pupae samples supports enhanced oxygen-free radical generation, as indicated by our findings. Increased antioxidant enzyme activity could be a compensatory mechanism in response to increased oxidative stress. The findings point to glutathione s transferase’s antioxidant activity in response to increasing oxidative stress in the treated group.

Selenium intake is not associated with the metabolic syndrome in Brazilian adolescents: an analysis of the Study of Cardiovascular Risk Factors in Adolescents.

Se reduces cellular inflammation and lipid peroxides; therefore, its association with CVD and the metabolic syndrome (MetS) has been studied. We aimed to investigate the association between Se intake and the MetS and its parameters (high waist circumference, hyperglycaemia, high blood pressure, high TAG and low HDL-cholesterol) in Brazilian adolescents between 12 and 17 years old. This research is part of the Study of Cardiovascular Risks in Adolescents (ERICA), a Brazilian nationwide school-based study with regional and national relevance. We assessed: (1) socio-demographic data (sex, age, type of school and maternal education) using a self-administered questionnaire; (2) dietary intake using a 24-h recall applied for the whole sample and a second one applied to a subsample to allow within-person variability adjustment; (3) anthropometric data (weight, height, waist circumference) and blood pressure using standardised procedures; and (4) biochemical analyses (fasting glucose, TAG and HDL-cholesterol). Logistic regression was applied, basing the analysis on a theoretical model. Median Se intake was 98·3 µg/d. Hypertension and hyperglycaemia were more prevalent among boys, while a high waist circumference was more frequent in girls, and low HDL-cholesterol levels were higher among private school students. The prevalence of the MetS was 2·6 %. No association between the MetS and its parameters and Se intake was found. This lack of association could be due to an adequate Se intake in the studied population.

Protective Effect of Borassus flabellifer Haustorium Extract against Alkoxyl Radical-Induced Cytotoxicity by Improving Glutathione Metabolism by Modulating Nrf2/Haeme Oxygenase-1 Expression

Aim The study was aimed to assess the ability of Borassus flabellifer haustorium methanolic extract (BHE) on de novo glutathione biosynthesis in normal and pro-oxidant exposed cells via Nuclear factor erythroid 2-related factor 2 (Nrf2) and haeme oxygenase-1 (HO1) signaling in 2,2′-Azobis(2-methylpropionamidine) di-hydrochloride (AAPH) induced cytotoxicity in normal intestinal epithelial cells (IEC-6 cells). Methods The in vitro antioxidant activity was determined in terms of radical scavenging and ex vivo hemolysis. The cytoprotective effect was studied using AAP H as the alkoxyl radical inducer in IEC-6 cell model. The mechanistic basis of protection is determined by Nrf2/HO1 expression using qPCR. Results In vitro screening observed DPPH, hydrogen peroxide and ABTS radical scavenging activity for the BHE; further, BHE also protected the oxidative hemolysis in the erythrocytes induced by AAPH. In IEC-6 cells, AAPH treatment significantly reduced the cell viability (p < 0.001) by inducing lipid peroxidation. Further, there observed a significant reduction in the activities of enzymes involved in the de novo glutathione biosynthesis (p < 0.01) and glutathione reductase in these cells. However, pretreatment with BHE (10, 25 and 50 µg/mL) dose-dependently protected from the cytotoxicity of AAPH-derived alkoxyl radicals (p < 0.05); besides, the de novo glutathione biosynthesis and regeneration of GSH from oxidized form was also increased in these cells. In corroboration with the biochemical parameters, the Nrf2/HO1 expression was upregulated by the BHE pretreatment concomitantly reducing the cellular lipid peroxidation products. The improvement glutathione biosynthesis was also observed in BHE alone treated cells. Conclusion The study indicated the potential of methanolic extract of Borassus flabellifer haustorium in enhancing the de novo glutathione biosynthesis in normal and pro-oxidant exposed cells by Nrf2/HO1 dependent manner, concomitantly mitigating the toxicity of AAPH-derived alkoxyl radicals in intestinal epithelial cells.

SLC7A11 Reduces Laser-Induced Choroidal Neovascularization by Inhibiting RPE Ferroptosis and VEGF Production.

In age-related macular degeneration (AMD), one of the principal sources of vascular endothelial growth factor (VEGF) is retinal pigment epithelium (RPE) cells under hypoxia or oxidative stress. Solute carrier family 7 member 11 (SLC7A11), a key component of cystine/glutamate transporter, regulates the level of cellular lipid peroxidation, and restrains ferroptosis. In our study, we assessed the role of SLC7A11 in laser-induced choroidal neovascularization (CNV) and explored the underlying mechanism. We established a mouse model of CNV to detect the expression level of SLC7A11 and VEGF during disease progression. We found the expression of the SLC7A11 protein in RPE cells peaked at 3 days after laser treatment, which was correlated with the expression of VEGF. Intraperitoneal injection of SLC7A11 inhibitor expanded the area of CNV. We examined functional proteins related to oxidative stress and Fe2+ and found laser-induced ferroptosis accompanied by increased Fe2+ content and GPX4 expression in the RPE-choroidal complex after laser treatment. We verified the expression of SLC7A11 in the ARPE19 cell line and the effects of its inhibitors on cell viability and lipid peroxidation in vitro. Application of SLC7A11 inhibitor and SLC7A11 knockdown increased the level of lipid peroxidation and reduced the cell viability of ARPE19 which can be rescued by ferroptosis inhibitors ferrostatin-1 (Fer-1) and liproxstatin-1 (Lip-1). Conversely, SLC7A11 overexpression induced resistance to erastin or RSL3-induced ferroptosis. Moreover, we tested the possible regulatory transcription factor NF-E2-related factor 2 (NRF2) of SLC7A11 by Western blot. Knock-down of NRF2 decreased the expression of SLC7A11. Our study suggests that SLC7A11 plays a key role in the laser-induced CNV model by protecting RPE cells from ferroptosis. SLC7A11 provides a new therapeutic target for neovascular AMD patients.

Pink Cedar (Acrocarpus fraxinifolius): its prophylactic role vs APAP–induced toxicity in rats and its antiviral activity vs HSV-1

APAP (N-acetyl-p-aminophenol) overdose induced cellular damage has been linked to oxidative assault by free radicals. Otherwise, constant emergence of resistant virus strains worldwide calls for an urgent need to develop therapeutic agents to improve the treatment of virus infection especially vs Herpes Simplex Virus-type 1 (HSV-1) which is a widespread/ repeated virus with no medical cure. Acrocarpus is a genus in family Fabaceae which is considered as a large economical & medicinal family. Here, we investigated the antioxidant activity of aqueous methanol extract of A. fraxinifolius leaves (AMEAFL) in vitro & in vivo vs APAP-induced organ toxicity & their antiviral/virucidal activity vs HSV 1 in vitro. In vivo, AMEAFL reduced serum cellular toxicity & cellular lipid peroxidation. It enhanced cellular antioxidants in a dose-dependent manner. In vitro, its total phenolic reached 392.4 mg/100 g with 85.3% of its antioxidant activity. It gave strong radical scavenging abilities (DPPH, 90.72%; •NO: 68.16% & O2 •−, 79.84%). It was non-toxic to VERO cells & the inhibitory activity to HSV1 was dose dependent. Their MIC, EC50 & SI were 72.6, 51.9, & 2.09 µg/ml. Direct contact between the AMEAFL & virus resulted in varying levels of virucidal action relying on its polyphenolic content. AFL has a dual effect. It has a prophylactic effect on APAP toxicity by increasing the endogenous antioxidant, as well as anti-HSV-1 activity by limiting virus attachment & viral multiplication at the early stages.

The Protective Effects of Carvacrol on Diphenhydramine-Induced Genotoxicity in Human Peripheral Blood Lymphocytes

Background and Objectives: Carvacrol is a natural antioxidant possessing various biological properties. Diphenhydramine is a first-generation antihistamine prescribed for allergies and the common cold. Recently, investigations have shown that diphenhydramine might cause genotoxicity. Antioxidants significantly act in defending cells against oxidative induced genotoxicity. Here, we assessed the protective effect of carvacrol, as a potent antioxidant, on diphenhydramine induced oxidative genotoxicity on human peripheral blood lymphocytes. Methods: Peripheral lymphocytes were treated as followed groups: diphenhydramine concentrations (200, 500 and 1000 µg/mL), diphenhydramine in combination with carvacrol (5 µg/mL), cisplatin (0.05 µg/mL) and cisplatin in combination with carvacrol. We evaluated the formation of micronucleus (MN), known as genotoxicity occurrence indicator, to demonstrate the possibility of diphenhydramine-induced genotoxicity. Furthermore, the level of oxidative stress was assumed by cellular glutathione oxidation and lipid peroxidation. Results: The results showed that high concentrations of diphenhydramine could cause oxidative stress damages by elevating the lipid peroxidation and glutathione oxidation. The frequency of micronucleus increased after diphenhydramine exposure (p < 0.05). Interestingly, carvacrol significantly decreased frequency of micronucleus and lipid peroxidation in lymphocytes exposed to high concentration of diphenhydramine. Conclusion: Our results further support the idea that carvacrol has beneficial effects in protecting cells against oxidative stress damages and diphenhydramine-induced genotoxicity.

Fermented Wheat Germ Extract as a Redox Modulator: Alleviating Endotoxin-Triggered Oxidative Stress in Primary Cultured Rat Hepatocytes.

Bioactive compounds such as benzoquinone derivates presented in fermented wheat germ extract (FWGE) have several positive effects on overall health status of humans and animals alike. Since available data regarding the antioxidant activity of FWGE are limited, the aim of our study was to investigate its effects on the cellular redox homeostasis applying primary hepatocyte cell cultures of rat origin. Cultures were challenged to lipopolysaccharide (LPS) treatment for 2 or 8 hours to trigger inflammatory response. Further, culture media were concomitantly supplemented with or without FWGE (Immunovet®, 0.1% and 1%). In order to monitor the metabolic activity of the cell cultures, CCK-8 test was applied, while reactive oxygen species (ROS) production was measured using Amplex Red method. Malondialdehyde concentration of culture media as a specific marker of lipid peroxidation and the activity of glutathione peroxidase in cell lysates were also determined to monitor the redox status of the cultures. Based on our findings, it can be concluded that FWGE did not show cytotoxic effects in any applied concentration in cell cultures. Furthermore, FWGE efficiently decreased cellular ROS production and lipid peroxidation rate in case of LPS-induced inflammatory response. However, without LPS treatment, higher concentration of FWGE increased the rate of both ROS and malondialdehyde synthesis. This observation may refer to the prooxidant activity of high dose FWGE, which is an important beneficial effect regarding tumor cells. However, in case of noninflamed hepatocytes, considering the results of glutathione peroxidase activity, the application of the product did not result in severe oxidative distress. In accordance with the abovementioned findings, FWGE as a redox modulator, applied in the appropriate concentration, can serve as a promising candidate in the supplementary therapy of patients suffering from various inflammatory diseases, decreasing the free radical generation, thus avoiding the occurrence of cytotoxic effects.

Up-regulated 2-alkenal reductase expression improves low-nitrogen tolerance in maize by alleviating oxidative stress.

In plants, cellular lipid peroxidation is enhanced under low nitrogen (LN) stress; this increases the lipid-derived reactive carbonyl species (RCS) levels. The cellular toxicity of RCS can be reduced by various RCS-scavenging enzymes. However, the roles of these enzymes in alleviating oxidative stress and improving nutrient use efficiency (NUE) under nutrient stress remain unknown. Here, we overexpressed maize endogenous NADPH-dependent 2-alkenal reductase (ZmAER) in maize; it significantly increased the tolerance of transgenic plants (OX-AER) to LN stress. Under LN condition, the biomass, nitrogen accumulation, NUE, and leaf photosynthesis of the OX-AER plants were significantly higher than those of the wild-type (WT) plants. The leaf and root malondialdehyde and H2 O2 levels in the transgenic plants were significantly lower than those in WT. The expression of antioxidant enzyme-related genes ZmCAT3, ZmPOD5 and ZmPOD13 was significantly higher in the transgenic lines than in WT. Under LN stress, the nitrate reductase activity in the OX-AER leaves was significantly increased compared with that in the WT leaves. Furthermore, under LN stress, ZmNRT1.1 and ZmNRT2.5 expression was upregulated in the OX-AER plants compared with that in WT. Overall, up-regulated ZmAER expression could enhance maize's tolerance to LN stress by alleviating oxidative stress and improve NUE.

Idebenone Ameliorates Rotenone-Induced Parkinson's Disease in Rats Through Decreasing Lipid Peroxidation.

Oxidative stress is considered one of the mechanisms responsible for neurodegenerative diseases, especially for Parkinson's disease. Since oxidative stress causes pathological changes in neuronal structures antioxidant compounds gained significant attention the last decades. Although several antioxidant compounds showed neuroprotective actions in Parkinson's disease models, only a few of them demonstrated protective effects against loss of striatal dopaminergic neurons. Idebenone is an analog of the well-known antioxidant compound coenzyme Q10 (CoQ10). Clinical safety of idebenone is well described, and due to its high antioxidant capacity currently used to treat Freidrich's ataxia and Alzheimer's disease. Like Parkinson's disease, these diseases are characterized by oxidative stress and impaired mitochondrial balance in neurons. However, knowledge about the effects of idebenone on Parkinson's disease is limited. Therefore, in this study we aimed to investigate and delineate the possible effects of idebenone in rotenone-induced Parkinson's disease models. Idebenone (200mg/kg, p.o.) inhibited the decrease of striatal expression of NAD(P)H dehydrogenase[quinone]-1, which is an essential element for mitochondrial respiration. Idebenone decreased the striatal levels of the lipid peroxidation products and increased the expression of glutathione peroxidase-4 (GPx-4), which is primarily known for lipid peroxidation and ferroptosis. Furthermore, idebenone mitigated motor impairment and increased tyrosine hydroxylase-positive neuron survival. Together our results thus indicate that that idebenone has protective effects against a rotenone insult with pleiotropic actions on the cellular oxidative enzymes and lipid peroxidation.

Effect of Vitamin C Administration 24 Hours After 5-Fluorouracil Versus its Concomitant Administration on Cellular Proliferation, Cell Death and Lipid Peroxidation in WI-38 Human Fibroblast Cell Line

Abstract:5-Fluorouracil (5-FU) is a routine anticancer agent for several cancer types, its short half-life requires continuous administration in high doses. This results in toxic side-effects to the normal tissues in the body. Vitamin C is an antioxidant which believed to impart cyto-protection to normal tissues in cancer patients treated with chemotherapeutic drugs.Aim of the study: to assess the potential benefit of vitamin C administration 24 hours after 5-FU treatment compared to its immediate supplementation on normal fibroblast cell line.Materials and methods: fibroblast cell line (WI-38) was divided into 5 groups. Group I not treated (control group), group II treated with 5-FU only and group III received vitamin C only. Groups IV and V received 5-FU with vitamin C simultaneously and after 24 hours of 5-FU administration, respectively. The viability of cells in all groups was determined using MTT assay. MDA Quantification Assay was used to determine lipid peroxidation. Flow cytometry was used for evaluation of the cell cycle and cell death. All recorded data was statistically analyzed.Results: Cells in group IV seems like group II fewer and rounded while in group V some of them adherent spindle and the others rounded non-adherent. The least viability was noted in group II. MDA levels were significantly lower in groups III compared to all the other groups. Cell cycle analysis revealed the presence of statistically significant differences between groups in different phases of the cycle. Flowcytometry analysis showed the highest apoptosis in groups II and IV. Conclusion: Co-treatment of normal fibroblasts with vitamin C along with 5-FU reduces cell death and lipid peroxidation while enhancing viability and proliferation in treated fibroblasts, indicating healing and repair. Vitamin C administration 24 hours after 5-FU is more effective in reducing cell death and lipid peroxidation compared to its concomitant administration with 5-FU.

ACADSB regulates ferroptosis and affects the migration, invasion, and proliferation of colorectal cancer cells.

Colorectal cancer (CRC) is one of the most pressing health issues in today's society. As such, it is imperative that the scientific community devise effective methods to inhibit the proliferation and metastasis of CRC cells. Ferroptosis is a recently discovered regulatory cell death mode mainly manifested by dysregulation of cellular iron metabolism and mitochondrial lipid peroxidation. ACADSB is a member of the acyl-CoA dehydrogenase. This study finds that ACADSB is lowly expressed in CRC tissues. Its expression is negatively correlated with N- and M-stage CRC but positively correlated with the overall survival rate of CRC patients. In addition, it finds that ACADSB is found in the mitochondria of cells. Overexpression of ACADSB inhibits CRC cell migration, invasion, and proliferation, while ACADSB knockdown has the opposite effect. More importantly, the study finds that ACADSB negatively regulates expression of glutathione reductase and glutathione peroxidase 4, the two main enzymes responsible for clearing glutathione (GSH) in CRC cells. ACADSB overexpression enhances the concentration of malondialdehyde, Fe+ , superoxide dismutase, and lipid peroxidation in CRC cells, but reduces the concentration of GSH. This is significant, as all of these are important indicators of ferroptosis. Evaluating the data as a whole, this paper speculates that ACADSB affects CRC cell migration, invasion, and proliferation by regulating CRC cell ferroptosis.