Lipid Peroxidation In Rats Research Articles

Lipid peroxidation and sphingolipid alterations in the cerebral cortex and hypothalamus of rats fed a high-protein diet

ObjectivesHigh-protein diets (HPDs) are widely accepted to enhance satiety and energy expenditure and thus have become a popular strategy to lose weight and facilitate muscle protein synthesis. However, long-term high-protein consumption could be linked with metabolic and clinical problems such as renal and liver dysfunctions. This study verified the effects of 8-wk high-protein ingestion on lipid peroxidation and sphingolipid metabolism in the plasma, cerebral cortex, and hypothalamus in rats. MethodsImmunoenzymatic and spectrophotometric methods were applied to assess oxidation-reduction (redox) biomarkers and neutral sphingomyelinase activity, whereas gas-liquid chromatography and high-performance liquid chromatography were used to examine sphingolipid levels. ResultsThe vast majority of HPD-related alterations was restricted to the hypothalamus. Specifically, an increased rate of lipid peroxidation (increased lipid hydroperoxides, 8-isoprostanes, and thiobarbituric acid reactive substances) associated with ceramide accumulation via the activation of de novo synthesis (decreased sphinganine), salvage pathway (decreased sphingosine), and sphingomyelin hydrolysis (decreased sphingomyelin and increased neutral sphingomyelinase activity) was noted. ConclusionsThis study showed that HPD substantially affected hypothalamic metabolic pathways, which potentially alter cerebral output signals to the peripheral tissues.

A Medicago truncatula calcineurin B-like protein, MtCBL13 confers drought sensitivity in Arabidopsis through ABA-dependent pathway

The Ca2+-CBL-CIPK complex is a crucial plant-specific signaling pathway involved in plant growth, development, and stress responses. However, the functions of the CBL/CIPK protein families from Medicago truncatula remain largely unknown. Here, we characterized a novel drought-responsive calcineurin B-like protein (CBL) gene, MtCBL13, in response to drought stress. MtCBL13 is a plasma membrane-localized protein predominantly expressed in roots. The transcript level of MtCBL13 was increased at the early stage of drought stress but sharply decreased with increasing exposure time. Transgenic Arabidopsis plants overexpressing MtCBL13 were sensitive to mannitol and ABA treatments at seed germination and seedling stages. Overexpression of MtCBL13 increased drought sensitivity in Arabidopsis, as evidenced by higher ROS accumulation, electrolyte leakage, lipid peroxidation, and water loss rate compared to the WT. Moreover, overexpression of MtCBL13 dramatically decreased the contents of proline, soluble sugar, soluble protein, and relative leaf water and inhibited photosynthetic efficiency and activities of CAT and SOD enzymes. The expression levels of stress marker genes, such as RD22 and DREB2A, were significantly reduced in MtCBL13 transgenic plants. Additionally, overexpression of MtCBL13 significantly upregulated ABI1/2 but inhibited ABI4/5 under drought stress. Our results indicate that MtCBL13 could negatively influence drought tolerance through the ABA-dependent pathway. The study provides novel insights into the understanding of the underlying mechanisms of CBL-mediated drought stress response in M. truncatula and could facilitate the genetic improvement of legumes through molecular breeding.

An assessment of the ameliorative role of hesperidin in Drosophila melanogaster model of cadmium chloride-induced toxicity

Cadmium chloride (CdCl2) is an important heavy metal widely regarded as an environmental contaminant. Hesperidin, a flavanone glycoside found in citrus fruits, has an established properties against free radicals, apoptosis, and inflammation. The present study investigated the protective actions of hesperidin on CdCl2-induced oxidative damage and inflammation in Drosophila melanogaster. For 7 consecutive days via their diet regimen, the flies were exposed to CdCl2 alone (0.05 mM) or in combination with hesperidin (50 and 100 μM). Exposure to CdCl2 significantly (p < 0.05) increased mortality rate of flies, whereas the survived flies demonstrated significant oxidative toxicity from decreased activities of catalase and Glutathione S-transferase (GST) and Total Thiol (T-SH) and Non-Protein Thiols (NPSH) levels as well as accumulation of Nitric Oxide (NO (nitrite/nitrate)), protein carbonyl and Hydrogen Peroxide (H2O2). However, hesperidin-supplemented diet improved Acetylcholinesterase (AChE) activity, mitochondrial metabolic rate (cell viability), locomotor activity, and amelioration of oxidative damage and lipid peroxidation induced by CdCl2. The hesperidin diet supplement boosted the antioxidant milieu and ameliorated the oxidative damage in the treated flies. Overall, the findings revealed that hesperidin improved antioxidative protective capacity in Drosophila melanogaster model of CdCl2-induced toxicity. This suggests hesperidin as a potential therapeutic agent against oxidative stress disorders due to exposure to CdCl2 and or related toxicants.

Effects of 1−MCP on Storage Quality and Enzyme Activity of Petals of Edible Rose Cultivar ‘Dianhong’ at Low Temperatures

To explore the effect of 1-methylcyclopropene (1−MCP) on the storage quality of edible roses, flowers of the edible rose variety ‘Dianhong’ were used as materials to study the effect of post-harvest 1−MCP fumigation (concentration of 30 μL/L). The measures included respiration intensity, water loss rate, antioxidant-related substance content (soluble sugar, crude fibre, AsA, anthocyanin, total phenols and MDA), enzyme activity (SOD, CAT, APX, PAL and PPO) and petal appearance quality in different storage periods, which could provide a theoretical reference for research and development on storage and preservation technology for edible rose petals. The results showed that, compared with the control, 1−MCP treatment reduced the initial respiration intensity of petals by more than 80%, slowed the water loss rate, increased the crude fibre content and effectively maintained the contents of soluble sugars, AsA, anthocyanins and total phenols. For the petals in the treatment group at the end of storage, the rate of water loss was 3.73%, the content of soluble sugar was only 17% (62.27 μg/g)—lower than that of fresh petals—and the content of AsA (0.33 mg/g) was the same as that of pre-storage (0.34 mg/g). The contents of total phenols and anthocyanins were 30.60% and 11.63% higher than those of the control group, respectively. In addition, 1−MCP treatment increased the activity of SOD, CAT, APX and PAL and inhibited the activity of PPO. The MDA content at the end of storage was 14.36% lower than that of the control, which reduced the rate of membrane lipid peroxidation. Correlation analysis showed that sensory quality of petals in the 1−MCP treatment group was positively correlated with respiratory intensity and soluble sugar content and negatively correlated with water loss rate, MDA and crude fibre content (p &lt; 0.05) among the four antioxidant enzymes. APX and PAL were positively correlated with anthocyanin content and total phenols content, respectively. These results confirmed that 1−MCP could effectively maintain the storage quality of edible rose petals by increasing the antioxidant capacity of petals and prolong the storage period of fresh petals to 49 days.

Adverse Effects of Organochlorine Pesticide Residues on Biochemical Parameters and Oxidative Stress in Libyan Agricultural Workers

Agricultural workers are in danger of being exposed to toxic substances such as pesticides. To estimate the individual danger of handling pesticides, the bio-monitoring of effects on agricultural workers is required. There has been no such research previously conducted among Libyan agricultural workers. This research was designed to study the biochemical parameters impacts of the pesticide contamination among Libyan agricultural workers at Aljebal Alakhtar, Libya. 45 blood samples were taken from male agriculture workers at Aljebal Alakhtar who had been exposed to pesticides in crop fields for a long time, while 25 blood samples were taken from a group of people who had not been exposed to pesticides (control). Kits were used to assess plasma ALT, AST, ALP, GST, SOD, total protein, albumin, globulin, total bilirubin, total cholesterol, triglycerides, HDL-C, LDL-C, VLDL-C, urea, and creatinine. The thiobarbituric acid reactive substances (TBARS) assay was used to evaluate lipid peroxidation in serum. Using a gas chromatography-electron capture detector, the blood samples were tested for organochlorine pesticide residues (GC-ECD). In comparison to controls, workers had significantly higher SOD, GST, ALP, AST, and ALT activities, as well as higher levels of lipid profile, total bilirubin, creatinine, and urea, as well as significantly higher TBARS concentrations. Furthermore, long-term pesticide exposure was also related to reduceing total protein, albumin, and globulin, as well as reduced HDL-C levels. Pesticide exposure seems to influence various biochemical markers in general. These biomarkers appear to be indicative of pesticide-related deleterious effects in agricultural workers, indicating that they should be used for routine monitoring of impacts.

Evaluation of Malondialdehyde Levels, Oxidative Stress and Host-Bacteria Interactions: Escherichia coli and Salmonella Derby.

Either extracts, cell-free suspensions or bacterial suspensions are used to study bacterial lipid peroxidation processes. Along with gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, and several other strategies, the thiobarbituric acid test is used for the determination of malondialdehyde (MDA) as the basis for the commercial test kits and the colorimetric detection of lipid peroxidation. The aim of the current study was to evaluate lipid peroxidation processes levels in the suspensions, extracts and culture supernatants of Escherichia coli and Salmonella Derby strains. The dependence of the formation of thiobarbituric acid-reactive substances levels in the cell extracts, the suspensions and cell-free supernatants on bacterial species, and their concentration and growth phase were revealed. The effect of bacterial concentrations on MDA formation was also found to be more pronounced in bacterial suspensions than in extracts, probably due to the dynamics of MDA release into the intercellular space. This study highlights the possible importance of MDA determination in both cell-free suspensions and extracts, as well as in bacterial suspensions to elucidate the role of lipid peroxidation processes in bacterial physiology, bacteria–host interactions, as well as in host physiology.

Filtration techniques are advantageous over colloidal centrifugation in improving freezability of low-quality buffalo bull (Bubalus bubalis) ejaculates

The study compared efficacy of three sperm selection techniques in improving freezability of low-quality Murrah buffalo bull ejaculates. Sephadex (SEP), Sephadex ion-exchange filtration (SIE), and 40/80% BoviPure ™ (BP) gradient centrifugation protocols were standardized (ejaculates, n = 24). In Experiment-I, Sephadex G-75, G-100, and combined Sephadex G (75–100) column filtrates were compared. In Experiment-II, BP protocols: 200 g-10 min, 250 g-5, and 10 min, 300 g-10, and 15 min were compared. In fresh semen, Sephadex G (75–100) filtration and 250 g-5 min BP protocol improved sperm functions and were used in Experiment-III, where SEP G (75–100), SIE G (75–100), and 250 g-5 min BP processed ejaculates (n = 48) were cryopreserved and compared at post-thaw stage. The mean recovery rate differed in order: SEP > SIE > BP. SIE filtration significantly improved progressive motility, livability, membrane integrity, bovine cervical mucus penetration and live non-apoptotic sperm. Compared with control, all three techniques equally reduced post-dilution and post-thaw lipid peroxidation (LPO) rate. SEP post-thaw filtrates observed lower cryocapacitation-like changes, LPO (C11‐BODIPY581/591), and higher active mitochondria than other treatments. SIE and SEP equally improved post-thaw acrosome-intact sperm over BP. Filtration techniques, preferably, Sephadex ion-exchange filtration can most efficiently process low-quality buffalo bull ejaculates for cryopreservation and improve freezability.

Curcumin improves the ability of donepezil to ameliorate memory impairment in Drosophila melanogaster: involvement of cholinergic and cnc/Nrf2-redox systems

One of the well-established models for examining neurodegeneration and neurotoxicity is the Drosophila melanogaster model of aluminum-induced toxicity. Anti-cholinesterase drugs have been combined with other neuroprotective agents to improve Alzheimer’s disease management, but there is not much information on the combination of anti-cholinesterases with dietary polyphenols to combat memory impairment. Here, we assess how curcumin influences some of the critical therapeutic effects of donepezil (a cholinesterase inhibitor) in AlCl3-treated Drosophila melanogaster. Harwich strain flies were exposed to 40 mM AlCl3 – alone or in combination with curcumin (1 mg/g) and/or donepezil (12.5 µg/g and 25 µg/g) – for seven days. The flies’ behavioral evaluations (memory index and locomotor performance) were analyzed. Thereafter, the flies were processed into homogenates for the quantification of acetylcholinesterase (AChE), catalase, total thiol, and rate of lipid peroxidation, as well as the mRNA levels of acetylcholinesterase (ACE1) and cnc/NRF2. Results showed that AlCl3-treated flies presented impaired memory and increased activities of acetylcholinesterase and lipid peroxidation, while there were decrease in total thiol levels and catalase activity when compared to the control. Also, the expression of ACE1 was significantly increased while that of cnc/NRF2 was significantly decreased. However, combinations of curcumin and donepezil, especially at lower dose of donepezil, significantly improved the memory index and biochemical parameters compared to donepezil alone. Thus, curcumin plus donepezil offers unique therapeutic effects during memory impairment in the D. melanogaster model of neurotoxicity.

Molecular mechanisms of Gupi Xiaoji decoction inducing apoptosis of human hepatoma HepG2 cells

Objective: To investigate the molecular mechanisms of Gupi Xiaoji decoction on apoptosis of human hepatoma cells HepG2. Methods: HepG2 cells were divided into 4 groups: control group (Control), blank serum group (Blank), Gupi Xiaoji Yin serum group (GPXJY) and cisplatin group (Positive). Eight duplicate holes were set in each group. After treated with Gupi Xiaoji Decoction-containing serum or cisplatin for 24 hours, the cell viability, the number of viable cells, the state of apoptosis, the cell cycle and the mitochondrial membrane potential were detected, and the level of lipid peroxidation (MDA) and glycolysis rate of the cells were detected. The expressions of apoptotic Bax, Bcl-2, and Caspase-3 proteins, and the contents of triacylglycerol (TG), cholesterol (TC), pyruvate and glucose in the cell supernatant were detected. Results: Compared with the control group, in the GPXJY group, the inhibition rate was increased (P＜0.05), the number of cells was decreased, the number of apoptosis-positive cells was increased (P＜0.01), the number of cells in the G1 phase was increased significantly (P＜0.05), and the cell membrane potential was decreased (P＜0.05,P＜0.01), the glycolytic function was inhibited significantly, the MDA level was increased, the expressions of Bax and Caspase-3 in the GPXJY group were increased, and the expression of Bcl-2 was decreased (P＜0.05, P＜0.01). In cell supernatant, the TC, TG and glucose contents were decreased significantly, and the pyruvate content was increased significantly (P＜0.05,P＜0.01). Conclusion: Gupi Xiaoji Decoction can induce apoptosis of HepG2 cells and may play a role in energy metabolism.

Kinetics of lipid radical formation in lipoproteins from β-thalassemia: Implication of cholesteryl esters and α-tocopherol

Vascular complications in β-thalassemia are associated with oxidative modification of lipoproteins under high oxidative stress. The lipid components of lipoproteins are oxidized via lipid peroxidation and produce lipid radicals (L•) as the key initial intermediates. Modification of lipid components, therefore, might result in alterations in the rate and products of lipid peroxidation. In this study, the kinetics of L• formation during the 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH)- and hemin-induced oxidation of low-density and high-density lipoproteins (LDL and HDL) from β-thalassemia patients and healthy volunteers were investigated using a specific and sensitive fluorescence probe for L•. Kinetic parameters, including initial lag time, propagation rate and total L• production, were calculated by monitoring a fluorescence-active NBD-Pen-L• adduct. Oxidation of thalassemia lipoproteins exhibited a significantly shorter lag time but a slower propagation rate of L• formation when compared with healthy lipoproteins. LDL showed higher resistance to oxidation during the initiation phase but higher L• formation than HDL. Our results indicated that the levels of α-tocopherol determined the initial lag time, whereas the levels of core lipids and cholesteryl esters, especially cholesteryl linoleate (CL), determined the propagation rate and total L• production. The difference in potency of AAPH and hemin supported that hemin preferentially targeted core lipids. Moreover, analysis of 13-hydroxyoctadecadienoic acid cholesteryl ester (13-HODE-CE)/CE ratio indicated that thalassemia lipoproteins have higher susceptibility to oxidation than healthy lipoproteins. In conclusion, our findings suggested that CL and α-tocopherol were implicated in the susceptibility of lipoproteins to lipid peroxidation in physiological and pathological conditions of β-thalassemia.

The Implications of Smoking on Lipid Peroxidation and Serum Antioxidant Status in Young Smokers with Coronary Heart Disease

Cigarette smoking is one of the leading causes of heart disease. Cigarette smoke contains oxidants playing a major role in oxidative stress by lowering antioxidant capacity and by increasing the level of lipid peroxidation. The study aims to estimate the total antioxidant capacity levels, lipid peroxidation and its relation to cardiovascular disease in young smokers. The study contains three groups. Group1 includes 120 healthy controls as nonsmokers, group2 includes 120 young active smokers with coronary heart disease (CHD) and group3 includes 120 young active smokers with diabetic CHD subjects who were attending the SRM Medical College Hospital in Tamil Nadu for cardiology and medicine. The Total Antioxidant Capacity and lipid peroxidation especially measured as malondialdehyde (MDA) was determined using a spectrophotometric technique. Enzyme-linked Immune Sorbent Assay was used to measure oxidized LDL (ox- LDL)" and "high-sensitivity CRP (hs-CRP). The total antioxidant capacity of smokers was found to be significantly lower than those of healthy controls p&lt;0.0001. On the other hand, MDA, ox-LDL and hs-CRP concentrations were considerably higher in smokers than healthy controls p&lt;0.0001. Interestingly smoking burden and smoking intensity also show a significant correlation with antioxidant capacity, lipid peroxidation (MDA) as well as with ox-LDL. The study concludes that cigarette smoking reduces the concentration of total antioxidant required for free radical scavenging which enhances the rate of lipid peroxidation and is one of the risk factors for CHD observed in smokers.

Post-harvest chitosan treatment suppresses oxidative stress by regulating reactive oxygen species metabolism in wounded apples.

Mechanical wound on fruit triggers the formation of reactive oxygen species (ROS) that weaken cell walls, resulting in post-harvest losses. This mechanism can be controlled by using fruit preservatives to stimulate fruit antioxidant enzyme activities for the detoxification of ROS. Chitosan is a safe and environmentally friendly preservative that modulates ROS in whole fruits and plant cells, but the effects of chitosan on the ROS metabolism of mechanically wounded apples during storage are unknown. Our study focused on exploring the effects of post-harvest chitosan treatment on ROS production, cell membrane integrity, and enzymatic and non-enzymatic antioxidant systems at fruit wounds during storage. Apple fruits (cv. Fuji) were artificially wounded, treated with 2.5% (w/v) chitosan, and stored at room temperature (21–25°C, RH = 81–85%) for 7 days. Non-wounded apples were used as healthy controls. The results showed that chitosan treatment stimulated the activities of NADPH oxidase and superoxide dismutase and increased the formation of superoxide anions and hydrogen peroxide in fruit wounds. However, malondialdehyde, lipoxygenase, and membrane permeability, which are direct biomarkers to evaluate lipid peroxidation and membrane integrity, were significantly decreased in the wounded fruits after chitosan treatment compared to the wounded control fruits. Antioxidant enzymes, such as peroxidase and catalase activities, were induced by chitosan at fruit wounds. In addition, ascorbate-glutathione cycle-related enzymes; ascorbate peroxide, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase and the content of substrates, mainly ascorbic acid, dehydroascorbate, reduced glutathione, and glutathione, were increased at fruit wounds by chitosan compared to the wounded control fruits. Our results show that wounding stimulated the production of ROS or oxidative stress. However, treatment with chitosan triggered antioxidant systems to scavenge ROS and prevent loss of fruit membrane integrity. Therefore, chitosan promises to be a favorable preservative in inducing tolerance to stress and maintaining fruit quality.

Robust and reliable detection of malondialdehyde in biological samples via microprobe-triggered surface-enhanced Raman spectroscopy

Malondialdehyde (MDA) is an endogenous genotoxic product of lipid peroxidation and its accumulation in the human body is associated with various diseases. To accurately understand the role of MDA in physiological and pathological processes, it is of great significance to develop a robust and reliable method for rapid detection of MDA. Hence, we proposed a surface-enhanced Raman spectroscopy (SERS) based method for MDA analysis, which employed 4-aminophenylthiophenol (PATP) as a SERS microprobe to recognize and quantify MDA. Qualitative analysis of MDA was performed using the fingerprint Raman spectrum of MDA adducts, and quantitative analysis of MDA was conducted using the characteristic peak of PATP at 1083 cm−1 as the internal standard. MDA detection can be performed in a mild reaction environment and the detection limit was below 0.50 μM. The proposed method successfully detected MDA in fresh blood samples and found satisfactory recovery rates in spiked samples. The proposed method allows reliable detection of endogenous toxic compounds in blood plasma, which is of great significance for monitoring oxidative stress indicators, such as lipid peroxidation rate and intensity, potential antioxidant capacity, and the degree of tissue peroxidation damage.

Effects of pramipexole on beta-amyloid1–42 memory deficits and evaluation of oxidative stress and mitochondrial function markers in the hippocampus of Wistar rat

Oxidative damage and mitochondrial dysfunction are two prominent pathological features and gradually understood as important pathogenic events for neurodegenerative diseases, including aging and Alzheimer’s disease (AD). The present study was aimed to explore the prolonged treatment of pramipexole (PPX) following amyloid beta (Aβ1–42)-induced cognitive impairments , oxidative stress, and mitochondrial dysfunction in a Wistar rat model. We have found that PPX (1.0 mg/kg, b.wt.) improves cognitive impairments of Aβ1–42-infused rats in Morris water maze. At the same time, PPX attenuated Aβ1–42-induced oxidative damage and increased reduced-glutathione content level, decreased lipid peroxidation rate and suppressed the activity of acetylcholinesterase and shows antioxidant effects. Additionally, PPX treatment has shown inhibition of mitochondrial reactive oxygen species production and restored mitochondrial membrane potential, oxidative phosphorylation, and enhanced ATP levels in Aβ1–42 rats. Furthermore, PPX treatment reduced bioenergetics loss and dynamics alterations by upregulating PGC-1α protein level and mitigating translocation of Bax and Drp-1 to mitochondria and cytochrome-c release into the cytoplasm. PPX also increased mitofusin-2 protein expression, a basic element of mitochondrial fusion process. We conclude that remedial role of PPX in mitigating oxidative damage and mitochondrial perturbation that are modulated in Aβ1–42 rats may have the propensity in AD pathogenesis.

YAP knockdown in combination with ferroptosis induction increases the sensitivity of HOS human osteosarcoma cells to pyropheophorbide-α methyl ester-mediated photodynamic therapy

Background and aims: This study was designed to explore the effects of Yes-associated protein (YAP) knockdown on human osteosarcoma (HOS) cell sensitivity to Pyropheophorbide-α methyl ester-mediated photodynamic therapy (MPPa-PDT), and to assess how YAP silencing in combination with treatment with the ferroptosis inducer Erastin improves HOS cell sensitivity to MPPa-PDT in an effort to better clarify the molecular mechanisms underlying these phenotypes.Methods: At 12 h post-MPPa-PDT, Hoechst staining and flow cytometry were conducted to evaluate the apoptotic death of HOS cells. The expression of YAP in these cells at 12 h post-MPPa-PDT treatment was assessed via Western blotting and immunofluorescent staining. BODIPY581/591-C11 was used to evaluate lipid peroxidation. Following shYAP lentiviral transduction, Western blotting was conducted to assess the expression of proteins associated with proliferation, apoptosis, and ferroptosis. EdU assays and clonogenic assays were performed to analyze cellular proliferation. Erastin-treated HOS cells were used to establish a ferroptosis model. Western blotting was used to measure ferroptosis-associated protein levels following shYAP and erastin treatment, while changes in proliferation and MDA levels in each group were examined using an MDA kit.Results: At 12 h post-MPPa-PDT, HOS cells exhibited apoptotic characteristics including nuclear fragmentation and pyknosis, with concomitant increases in apoptosis-associated proteins as detected via Western blotting and apoptotic induction as measured via flow cytometry. Phosphorylated YAP levels fell and non-phosphorylated YAP levels rose following such treatment. Transfection with shYAP was successful as a means of generating stable HOS cell lines, and Western blotting analyses of these cells revealed reductions in proteins associated with cellular proliferation together with the upregulation of apoptosis-related proteins. MDA assays indicated that erastin combined with YAP knockdown enhanced the sensitivity of HOS cells to MPPa-PDT treatment.Conclusions: These data indicate that ferroptosis and YAP knockdown can enhance osteosarcoma cell sensitivity to MPPa-PDT therapy.

Preliminary study of the ameliorative effects of melatonin on cadmium-induced morphological and biochemical alterations in the rat Harderian gland.

Herein is reported, for the first time in the rat Harderian gland (HG), the counteractive action of melatonin (Mlt), a well-known antioxidant radical scavenger, on the increased oxidative stress damages induced by a pro-oxidant substance, cadmium (Cd), an environmental pollutant also considered as endocrine disruptor. HG, an infraorbital gland present in almost all terrestrial vertebrates, produces a lipid secretion to lubricate the eyeball, as well as porphyrin/Mlt as light transducers. Moreover, HG is an extra-gonadal source of steroid sex hormones. Via ex vivo experiments lasting for 24 h, we verified the increased lipid peroxidation in Cd-treated glands, producing morphological alteration of the glandular epithelium, as well as an increased porphyrins accumulation. Moreover, Cd also induced a decreased protein level of the steroidogenic enzymes steroidogenic acute regulatory (StAR) and 3βHSD, and an increased mast cell number. Results obtained with Mlt cotreatment demonstrated that it decreased the levels of Cd-induced oxidative damage, with reversal of all the observed modification. Furthermore, the TUNEL assay showed that the increased number of apoptotic cells in Cd-treated HG was counteracted by the contemporaneous Mlt administration. Results confirmed that Mlt treatment restored the levels of two autophagy markers, LC3 and p62, counteracting the autophagy Cd-induced. Interestingly, the positive effects of Mlt alone were highlighted by the decreased rate of lipid peroxidation as compared with the control, confirming its antioxidant action. Combined data further confirmed the antioxidant action of Mlt in counteracting the degeneration provoked by reactive oxygen species (ROS) in the rat HG, a tissue extremely susceptible to oxidative stress condition.

Folic Acid Confers Tolerance against Salt Stress-Induced Oxidative Damages in Snap Beans through Regulation Growth, Metabolites, Antioxidant Machinery and Gene Expression.

Although the effect of folic acid (FA) and its derivatives (folates) have been extensively studied in humans and animals, their effects are still unclear in most plant species, specifically under various abiotic stress conditions. Here, the impact of FA as a foliar application at 0, 0.1, and 0.2 mM was studied on snap bean seedlings grown under non-saline and salinity stress (50 mM NaCl) conditions. The results indicated that under salinity stress, FA-treated plants revealed a significant (p ≤ 0.05) increase in growth parameters (fresh and dry weight of shoot and root). A similar trend was observed in chlorophyll (Chl b), total chlorophyll, carotenoids, leaf relative water content (RWC), proline, free amino acids (FAA), soluble sugars, cell membrane stability index (CMSI), and K, Ca, and K/Na ratio compared to the untreated plants. In contrast, a significant decrease was observed in Na and salinity-induced oxidative damage as indicated by reduced H2O2 production (using biochemical and histochemical detection methods) and rate of lipid peroxidation (malondialdehyde; MDA). This enhancement was correlated by increasing the activities of antioxidant enzymes, i.e., superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (G-POX), and ascorbate peroxidase (APX). Gene expression analyses conducted using qRT-PCR demonstrated that genes coding for the Na+/H+ antiporter protein Salt Overly Sensitive 1 (SOS1), the tonoplast-localized Na+/H+ antiporter protein (NHX1), and the multifunctional osmotic protective protein (Osmotin) were significantly up-regulated in the FA-treated plants under both saline and non-saline treatments. Generally, treatment with 0.2 mM FA was more potent than 0.1 mM and can be recommended to improve snap bean tolerance to salinity stress.

Hyperammonaemia induces mitochondrial dysfunction and neuronal cell death

Background & AimsIn cirrhosis, astrocytic swelling is believed to be the principal mechanism of ammonia neurotoxicity leading to hepatic encephalopathy (HE). The role of neuronal dysfunction in HE is not clear. We aimed to explore the impact of hyperammonaemia on mitochondrial function in primary co-cultures of neurons and astrocytes and in acute brain slices of cirrhotic rats using live cell imaging.MethodsTo primary cocultures of astrocytes and neurons, low concentrations (1 and 5 μM) of NH4Cl were applied. In rats with bile duct ligation (BDL)-induced cirrhosis, a model known to induce hyperammonaemia and minimal HE, acute brain slices were studied. One group of BDL rats was treated twice daily with the ammonia scavenger ornithine phenylacetate (OP; 0.3 g/kg). Fluorescence measurements of changes in mitochondrial membrane potential (Δψm), cytosolic and mitochondrial reactive oxygen species (ROS) production, lipid peroxidation (LP) rates, and cell viability were performed using confocal microscopy.ResultsNeuronal cultures treated with NH4Cl exhibited mitochondrial dysfunction, ROS overproduction, and reduced cell viability (27.8 ± 2.3% and 41.5 ± 3.7%, respectively) compared with untreated cultures (15.7 ± 1.0%, both p <0.0001). BDL led to increased cerebral LP (p = 0.0003) and cytosolic ROS generation (p <0.0001), which was restored by OP (both p <0.0001). Mitochondrial function was severely compromised in BDL, resulting in hyperpolarisation of Δψm with consequent overconsumption of adenosine triphosphate and augmentation of mitochondrial ROS production. Administration of OP restored Δψm. In BDL animals, neuronal loss was observed in hippocampal areas, which was partially prevented by OP.ConclusionsOur results elucidate that low-grade hyperammonaemia in cirrhosis can severely impact on brain mitochondrial function. Profound neuronal injury was observed in hyperammonaemic conditions, which was partially reversible by OP. This points towards a novel mechanism of HE development.Lay summaryThe impact of hyperammonaemia, a common finding in patients with liver cirrhosis, on brain mitochondrial function was investigated in this study. The results show that ammonia in concentrations commonly seen in patients induces severe mitochondrial dysfunction, overproduction of damaging oxygen molecules, and profound injury and death of neurons in rat brain cells. These findings point towards a novel mechanism of ammonia-induced brain injury in liver failure and potential novel therapeutic targets.

Iminodisuccinic acid enhances antioxidant and mineral element accumulation in young leaves ofZiziphus jujuba

AbstractJujube leaf tea, which is made from the young leaves ofZiziphus jujuba, is a novel functional herb tea or infusion that inhibits the central nervous system. In the current study, the effects of iminodisuccinic acid (IDS), as a metal complexing agent, on mineral element content, oxidative damage, antioxidant enzyme activities, and antioxidant accumulation in the young and mature leaves ofZ. jujubawere investigated. Results demonstrated that foliar fertilization with ionic (FeCl2and ZnCl2) and chelated (Fe-IDS and Zn-IDS) fertilizers could drastically enhance iron and zinc contents, coupled with increased vitamin C level, glutathione accumulation, total phenolic content, and total antioxidant capacity (evaluated based on the Fe3+reducing power of leaf extracts), compared with the control, particularly in young leaves. However, chelated fertilizers considerably reduced the chlorophyll level, H2O2content, and lipid peroxidation rate than ionic fertilizers, particularly in young leaves. Compared with the control, chelated fertilizers induced greater superoxide dismutase and catalase activities, particularly in young leaves. Moreover, decreased enzyme activities were observed in the ionic fertilizer-treated leaves compared with the control-treated leaves. Thus, using a chelating agent could improve the accumulation of mineral elements and antioxidants in young leaves by reducing metal-mediated reactive oxygen species toxicity.

Early oxidative burst and anthocyanin-mediated antioxidant defense mechanism impart resistance against Sclerotinia sclerotiorum in Indian mustard

The current study builds on our prior findings that anthocyanin buildup around the pathogen inoculation site confers resistance to S. sclerotiorum resistance in Indian mustard. However, the mechanism by which anthocyanin accumulation confers resistance is largely unknown. To better understand this mechanism, we compared the disease responses and biochemical profiling of two contrasting and wild type genotypes of Indian mustard [Sclerotinia stem rot-resistant RH 1222–28 (WR) and susceptible Varuna (WS)], as well as two anthocyanin contrasting mutants [anthocyanin-more (PM) and anthocyanin-devoid (AM) mutant] during different infection phases. Regardless of the inoculation time, disease examination revealed that WR and PM had considerably (P ≤ 0.05) lower mean lesion length (MLL) and rate of lesion expansion than WS and AM. Compared to WS and AM, biochemical results showed that WR and PM responses to infection were earlier, more timely regulated, and more robust. In the resistant WR and PM, hydrogen peroxide (H2O2) and superoxide anions (O2−1) accumulated rapidly and peaked during the early infection stage (2 days after inoculation; DAI), whereas in the susceptible WS and AM, accumulation was stronger and more intense in the later infection stage (8 DAI). Compared to the susceptible genotype (WS), the resistant genotype (WR) had significantly higher anthocyanin accumulation, a lower rate of lipid peroxidation, and a strong, efficient, and timely regulated antioxidant system that limited pathogen colonization and disease development. The anthocyanin-rich mutant (PM) is more resistant to ROS-induced oxidative damage. It has a slower rate of lesion development than the anthocyanin-deficient (AM) mutant, which has lower anthocyanin accumulation and higher oxidative stress with weak antioxidative potential, resulting in significantly (P ≤ 0.05) longer stem lesion length and rate of lesion expansion. These findings imply that during distinct infection phases of S. sclerotiorum, a well-coordinated oxidants/antioxidants system in terms of intensity and timing regulates Sclerotinia stem rot resistance/susceptibility. Overall, anthocyanin accumulation around the pathogen infection site appears to play a critical role in altering the ROS producing and scavenging machinery in Indian mustard, which contributes to resistance to S. sclerotiorum.