Increase In Peroxidation Levels Research Articles

2-iodohexadecanal induces autophagy during goiter involution

BackgroundIodine plays an important role in thyroid physiology and biochemistry. The thyroid is capable of producing different iodolipids such as 2-iodohexadecanal (2-IHDA). Data from different laboratories have shown that 2-IHDA inhibits several thyroid parameters and it has been postulated as intermediary on the action of iodide function. ObjectiveTo explore different mechanisms involved during the involution of the hyperplastic thyroid gland of Wistar rats towards normality induced by 2-IHDA. Methods: Goiter was induced by the administration of MMI for 10 days, then the treatment was discontinued and Wistar rats were injected with 2-IHDA or KI. ResultsDuring involution, 2-IHDA treatment reduced PCNA expression compared to spontaneous involution. KI treatment caused an increase of Caspase-3 activity and TUNEL-positive cells. In contrast, 2-IHDA failed to alter this value but induced an increase of LC3B expression. KI but not 2-IHDA led to an increase in peroxides levels, catalase and glutathione peroxidase activity. ConclusionsWe demonstrated that 2-IHDA, in contrast to iodide, did not lead to an increase in oxidative stress or apoptosis induction, indicating that the involution triggered by 2-IHDA in Wistar rats, is primarily due to the inhibition of cell proliferation and the induction of autophagy.

Nitro-oxidative response to internalized multi-walled carbon nanotubes in Brassica napus and Solanum lycopersicum

In addition to their beneficial effects on plant physiology, multi-walled carbon nanotubes (MWCNTs) are harmful to plants in elevated concentrations. This study compared the effects of two doses of MWCNT (10 and 80 mg/L) in Brassica napus and Solanum lycopersicum seedlings focusing on nitro-oxidative processes. The presence of MWCNTs was detectable in the root and hypocotyl of both species. Additionally, transmission electron microscopy analysis revealed that MWCNTs are heavily transformed within the root cells forming large aggregates. The uptake of MWCNTs negatively affected root viability and root cell proliferation of both species, but more intense toxicity was observed in S. lycopersicum compared to B. napus. The presence of MWCNT triggered more intense protein carbonylation in the relative sensitive S. lycopersicum, where increased hydrogen peroxide levels were observed. Moreover, MWCNT exposure increased the level of physiological protein tyrosine nitration which was more intense in S. lycopersicum where notable peroxynitrite accumulation occurred. These suggest for the first time that MWCNT triggers secondary nitro-oxidative stress which contributes to its toxicity. Moreover, the results indicate that the extent of the nitro-oxidative processes is associated with the extent of MWCNT toxicity.

The primary neurotoxic factor, Lansamide I, from Clausena lansium fruits and metabolic dysfunction invoked

Wampee (Clausena lansium) is a common fruit in South Asia. The pulp is a tasty food, and the seed is a typical traditional herb in China. However, we identified a primary toxic compound, Lansamide I, by NMR and X-ray diffraction of single-crystal. The compound occurred at 4.17 ± 0.16 mg/kg of dried seed and 0.08 ± 0.01 g/kg of fresh fruit. In our phenotype-based toxicity investigation, the compound caused decreased hatchability of zebrafish eggs, increased malformations such as enlarged yolk sacs and pericardial edema, and delayed body length development. Moreover, the compound also caused nerve cell damage and decreased locomotor activity. The compound caused an increase in peroxidation levels in vivo, with increases in both malondialdehyde and superoxide dismutase levels, but did not interfere with acetylcholinesterase levels. Metabolomic studies found that the compound caused significant up-regulation of 16 metabolites, mainly amino acids and peptides, which were involved in the nucleotide metabolism pathway and the betaine biosynthesis module. The qRT-PCR revealed that the substance interfered with the mRNA expression of tat and dctpp. These discoveries offer fresh perspectives on the toxicity mechanisms and metabolic response to the primary harmful molecules in wampee, which could inform the rational usage of wampee resources.

Nickel chloride generates cytotoxic ROS that cause oxidative damage in human erythrocytes

BackgroundNickel is a heavy metal that is regarded as a possible hazard to living organisms due to its toxicity and carcinogenicity. Nickel chloride (NiCl2), an inorganic divalent Ni compound, has been shown to cause oxidative stress in cells by altering the redox equilibrium. We have investigated the effect of NiCl2 on isolated human erythrocytes under in vitro condition. MethodsIsolated erythrocytes were treated with different concentrations of NiCl2 (25–500 µM) for 24 h at 37 ºC. Hemolysates were prepared and several biochemical parameters were analyzed in them. ResultsTreatment of erythrocytes with NiCl2 enhanced the intracellular generation of reactive oxygen species (ROS). A significant increase in hydrogen peroxide levels and oxidation of proteins and lipids was also seen. This was accompanied by a reduction in levels of nitric oxide, glutathione, free amino groups and total sulfhydryl groups. NiCl2 treatment impaired both enzymatic and non-enzymatic defense systems, resulting in lowered antioxidant capacity and diminished ability of cells to quench free radicals and reduce metal ions. NiCl2 exposure also had an inhibitory effect on the activity of enzymes involved in pathways of glucose metabolism (glycolytic and pentose phosphate shunt pathways). Increased level of methemoglobin, which is inactive in oxygen transport, was also seen. The rate of heme breakdown increased resulting in the release of free iron. Exposure to NiCl2 led to considerable cell lysis, indicating damage to the erythrocyte membrane. This was supported by the inhibition of membrane bound enzymes and increase in the osmotic fragility of NiCl2 treated cells. NiCl2 treatment caused severe morphological alterations with the conversion of normal discocytes to echinocytes. All changes were seen in a NiCl2 concentration-dependent manner. ConclusionNiCl2 generates cytotoxic ROS in human erythrocytes which cause oxidative damage that can decrease the oxygen carrying capacity of blood and also lead to anemia.

Redox status of juvenile Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), fed diets supplemented with poultry liver protein hydrolysate as feed aditive

Plant ingredients, when used as substitutes for animal protein ingredients, can negatively influence fish growth. Thus, feed additives have been used to enhance feed consumption, nutrient utilization efficiency and stress tolerance under intensive management conditions. One such potential feed additive in aquafeeds is poultry liver protein hydrolysate (PLPH), which is rich in essential amino acids and has in vitro antioxidant and antibacterial properties. In this study, we aimed to evaluate the effect of poultry liver protein hydrolysate as feed additive on the productive performance of Nile tilapia reared in a water recirculation system and investigate stress responses and redox status after an air exposure challenge. Nile tilapia juveniles were randomly distributed in 24 aquariums and fed plant-based diets supplemented with increasing levels of PLPH (0, 10, 20, and 40 g/kg) over a 45-day period. At the end of the experiment, we did not observe a significant effect of PLPH on productive performance variables or body indices (P > 0.05). Air exposure triggered stress responses in fish, as evidenced by an increase in blood glucose (P < 0.05). However, PLPH supplementation did not mitigate this effect (P > 0.05). Regarding redox status, a quadratic effect of PLPH supplementation was observed on malondialdehyde (P = 0.003) levels, as well as the activities of superoxide dismutase (P = 0.015), catalase (P = 0.015), and glutathione S-transferase (P = 0.001). Optimum PLPH supplementation levels were estimated at 25.14, 25.91, 22.57, and 18.83 g/kg, respectively, for these redox parameters. Increasing PLPH levels decreased carbonylated protein contents (P = 0.001) but increased hydrogen peroxide levels in the gills (P = 0.006). Although PLPH supplementation improved antioxidant enzyme activity, and attenuated protein damage, it concurrently increased reactive oxygen species production and lipid peroxidation. Further studies are necessary to elucidate the underlying mechanisms of action by which protein hydrolysates influence the redox status of fish reared under intensive management.

Constitutive knock-in of MnSODK68R causes dilated cardiomyopathy and senescence in mice

The mitochondrial superoxide dismutase (SOD2 or MnSOD) is an essential enzyme for managing oxidative stress, particularly by removing the highly reactive superoxide generated during the normal functioning of the electron transport chain. The activity of MnSOD is regulated post-translationally by acetylation, specifically at lysine 68. The deacetylated form of MnSOD is catalytically active, and it has been shown that the deacetylation mimic, MnSOD K68R in which lysine 68 has been replaced with arginine, has upregulated dismutase activity in MCF7 and T47D human breast cancer cells. Overexpression of MnSOD has been shown to increase lifespan and protect against oxidative stress in the aging heart. We investigated a MnSOD K68R knock-in mouse with ubiquitous expression of the mutant enzyme and expected similar effects as the MnSOD overexpressing mice. However, we have found that MnSOD K68R homozygous knock-in mice develop dilated cardiomyopathy and have significantly decreased ejection fraction as evidenced by echocardiography at a young age. These mice also exhibit lower blood pressure compared to wild-type mice. Strikingly, these mice exhibit higher body weight, with increased lean mass and food consumption. Mitochondria isolated from MnSOD K68R knock-in mouse hearts showed higher respiratory capacity than WT counterparts. Biochemical analysis revealed increased lipid peroxidation, oxidized peroxiredoxin and senescence markers, possibly indicative of a premature aging phenotype. We conclude that MnSOD constitutive function upregulation may produce a sustained increase in hydrogen peroxide levels that could cause senescence and lead to dilated cardiomyopathy. This research was funded by NCI grant R01CA152601 and, R01CA214025, and the Cancer Prevention and Research Institute of Texas grant number RR20012. JS is supported by T32 AG 021890. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

An aqueous olive leaf extract (OLE) ameliorates parameters of oxidative stress associated with lipid accumulation and induces lipophagy in human hepatic cells.

Fatty liver is a disease characterized by a buildup of lipids in the liver, often resulting from excessive consumption of high-fat-containing foods. Fatty liver can degenerate, over time, into more severe forms of liver diseases, especially when oxidative stress occurs. Olive leaf extract (OLE) is a reliable source of polyphenols with antioxidant and hypolipidemic properties that have been successfully used in medicine, cosmetics, and pharmaceutical products. Using "green" solvents with minimal impact on the environment and human health, which simultaneously preserves the extract's beneficial properties, represents one of the major challenges of biomedical research. In the present study, we assayed the potential antioxidant and lipid-lowering effect of a "green" OLE obtained by a water ultrasound-assisted extraction procedure, on the human hepatic HuH7 cell line, treated with a high concentration of free fatty acids (FFA). We found that high FFA concentration induced lipid accumulation and oxidative stress, as measured by increased hydrogen peroxide levels. Moreover, the activity of antioxidant enzymes, catalase, superoxide dismutase, and glutathione peroxidase, was reduced upon FFA treatment. Coincubation of high FFA with OLE reduced lipid and H2O2 accumulation and increased the activity of peroxide-detoxifying enzymes. OLE ameliorated mitochondrial membrane potential, and hepatic parameters by restoring the expression of enzymes involved in insulin signaling and lipid metabolism. Electron microscopy revealed an increased autophagosome formation in both FFA- and FFA + OLE-treated cells. The study of the autophagic pathway indicated OLE's probable role in activating lipophagy.

Identification of the Citrus Superoxide Dismutase Family and Their Roles in Response to Phytohormones and Citrus Bacterial Canker

Superoxide dismutases (SODs) play critical roles in plants, especially in the maintenance of redox homeostasis. The response of SODs in Citrus (Citrus sinensis (L.) Osbeck) to citrus bacterial canker (CBC) infection were investigated. The CsSODs were identified, and their gene structures, phylogeny, conserved domains and motifs, predicted interactions, and chromosomal distribution were analyzed. CsSOD expression in response to stress-related plant hormones (salicylic acid, SA; methyl jasmonate, MeJA; and abscisic acid, ABA) and Xanthomonas citri subsp. citri (Xcc) infection were also investigated. Thirteen CsSODs were identified in C. sinensis, including four Fe/MnSODs and nine Cu/ZnSODs with typical functional domains. The CsSODs were distributed on chromosomes 3, 5, 7, and 8. Specific hormone-response motifs were identified in the gene promoter regions. Ten genes were induced by MeJA treatment, as shown by qRT-PCR, and were upregulated in the CBC-susceptible Wanjincheng citrus variety, while CsSOD06 and CsSOD08 were upregulated by ABA in both the Wanjincheng and the CBC-resistant Kumquat varieties. Xcc infection significantly altered the levels of most CsSODs. The overexpression of CsSOD06 and CsSOD08 resulted in increased hydrogen peroxide levels and SOD activity. Our findings highlight the significance of SOD enzymes in the plant response to pathogen infection and have a potential application for breeding CBC-tolerant citrus varieties.

Exogenous seed treatment with proline and its consequences to Norway spruce (Picea abies (L.) H. Karst) seedling establishment

Accumulation of proline is a defense mechanism against external stress conditions, preventing damage to the structure and function of cells and improving plant development processes, such as germination. The purpose of this study was to investigate proline treatment as a means of improving the germination and development of Norway spruce seedlings. The effect of exogenous proline has been studied in three stages of initial plant development. The collected seeds were soaked in water or 8 mM proline solution and placed on the germinators. The germination capacity and the mean germination time were determined. Seedlings with radicles &gt;10 mm were transferred to the sand-peat substrate at a constant temperature of 20 °C. Seedlings at 3 subsequent developmental stages (S1 – germinated seeds with radicles &gt; 3 mm; S2 – seedlings with radicles &gt;10 mm; S3 – established seedlings grown for 90 days) were examined for the oxygen consumption rate, total antioxidant capacity, hydrogen peroxide level, malondialdehyde level and intracellular proline content. Proline treatment was conducive to lowering the levels of hydrogen peroxide and malondialdehyde at stage S1. At the subsequent stages of development, the levels of hydrogen peroxide and malondialdehyde increased, and at the S3 stage, there was also a marked increase in total antioxidant capacity. At stage S3, the seedlings of the proline treatment were characterized by a lower total mass, and the response to exogenous proline was stronger in the root tissues than in the leaves. The oxygen consumption rate was higher for the proline treatment at all stages of development. Seedlings at the analyzed stages of establishment differed in response to proline treatment. Exogenous proline had some beneficial effects during the first phase of germination by reducing the level of hydrogen peroxide and improving the condition of lipid membranes. In the subsequent stages of seedling development, in response to the same concentration of proline solution, undesirable effects, such as an increase in hydrogen peroxide levels and damage to cytoplasmic membranes, were observed. Optimal concentrations of exogenous proline should be determined prior to commercial use of proline treatment to improve plant stress tolerance.

The RelB-BLNK Axis Determines Cellular Response to a Novel Redox-Active Agent Betamethasone during Radiation Therapy in Prostate Cancer.

Aberrant levels of reactive oxygen species (ROS) are potential mechanisms that contribute to both cancer therapy efficacy and the side effects of cancer treatment. Upregulation of the non-canonical redox-sensitive NF-kB family member, RelB, confers radioresistance in prostate cancer (PCa). We screened FDA-approved compounds and identified betamethasone (BET) as a drug that increases hydrogen peroxide levels in vitro and protects non-PCa tissues/cells while also enhancing radiation killing of PCa tissues/cells, both in vitro and in vivo. Significantly, BET increases ROS levels and exerts different effects on RelB expression in normal cells and PCa cells. BET induces protein expression of RelB and RelB target genes, including the primary antioxidant enzyme, manganese superoxide dismutase (MnSOD), in normal cells, while it suppresses protein expression of RelB and MnSOD in LNCaP cells and PC3 cells. RNA sequencing analysis identifies B-cell linker protein (BLNK) as a novel RelB complementary partner that BET differentially regulates in normal cells and PCa cells. RelB and BLNK are upregulated and correlate with the aggressiveness of PCa in human samples. The RelB-BLNK axis translocates to the nuclear compartment to activate MnSOD protein expression. BET promotes the RelB-BLNK axis in normal cells but suppresses the RelB-BLNK axis in PCa cells. Targeted disruptions of RelB-BLNK expressions mitigate the radioprotective effect of BET on normal cells and the radiosensitizing effect of BET on PCa cells. Our study identified a novel RelB complementary partner and reveals a complex redox-mediated mechanism showing that the RelB-BLNK axis, at least in part, triggers differential responses to the redox-active agent BET by stimulating adaptive responses in normal cells but pushing PCa cells into oxidative stress overload.

No-ozone cold plasma can kill oral pathogenic microbes in H2O2-dependent and independent manner

To apply the sterilisation effect of low-temperature plasma to the oral cavity, the issue of ozone from plasma must be addressed. In this study, a new technology for generating cold plasma with almost no ozone is developed and is named Nozone (no-ozone) Cold Plasma (NCP) technology. The antimicrobial efficacy of the NCP against four oral pathogens is tested, and its specific mechanism is elucidated. The treatment of NCP on oral pathogenic microbes on a solid medium generated a growth inhibition zone. When NCP is applied to oral pathogens in a liquid medium, the growth of microbes decreased by more than 105 colony forming units, and the bactericidal effect of NCP remained after the installation of dental tips. The bactericidal effect of NCP in the liquid medium is due to the increase in hydrogen peroxide levels in the medium. However, the bactericidal effect of NCP in the solid medium depends on the charged elements of the NCP. Furthermore, the surface bactericidal efficiency of the dental-tip-installed NCP is proportional to the pore size of the tips and inversely proportional to the length of the tips. Overall, we expect this NCP device to be widely used in dentistry in the near future.

SARS-CoV-2 induces mitochondrial dysfunction and cell death by oxidative stress/inflammation in leukocytes of COVID-19 patients

The inflammation and activation of the immune system induced by SARS-CoV-2 are mediated by a pro-oxidant microenvironment that can induce cytotoxic effects that enhance tissue damage, favoring organic deterioration. We investigated whether the induction of oxidative stress and inflammation by COVID-19 infection could inhibit mitochondrial function and cause cellular damage in leukocytes. We evaluated levels of oxidative/inflammation markers and their correlation with mitochondrial function and leukocyte cell death in COVID-19 patients at two moments: viremia and severe sepsis with multi-organ failure. COVID-19 induces increased oxidative stress and inflammation markers that activate cellular damage processes. In the viremia stage, an increase in peroxide, nitric oxide, carbonylated proteins, and IL-6 was observed, which was correlated with a marked inhibition of mitochondrial function, decreased cell viability, early apoptosis, necrosis, and leukocytes-reactivity. The severe sepsis stage with multi-organ failure also showed a further increase in levels of peroxide, carbonylated proteins, and IL-6, with a slight decrease in nitric oxide. This oxidative process and inflammation were correlated with less inhibition of mitochondrial function, decreased cell viability and an increase in late apoptosis, and morphology changes evidencing damage in the leukocytes. SARS-CoV-2 induced damage promotes levels of oxidative stress and inflammation markers and mitochondrial dysfunction that potentiate morphological changes and cell death in leukocytes. These processes explain the rapid changes in the immune system, and that present an initial over-activation and early massive death due to SARS-CoV-2 infection, promoting endothelial-alveolar damage that would cause multi-organ failure, sustained by oxidative stress and inflammation.

Cellular antioxidant mechanisms control immunoglobulin light chain-mediated proximal tubule injury

A major cause of morbidity and mortality in multiple myeloma is kidney injury from overproduction of monoclonal immunoglobulin light chains (FLC). FLC can induce damage through the production of hydrogen peroxide, which activates pro-inflammatory and pro-apoptotic pathways. The present study focused on catalase, a highly conserved antioxidant enzyme that degrades hydrogen peroxide. Initial findings were that FLC increased hydrogen peroxide levels but also decreased catalase levels and activity in proximal tubule epithelium. In order to clarify, we showed that the phosphatidylinositol 3-kinase inhibitor, LY294002, inhibited FLC-induced Akt-mediated deactivation of Forkhead box O class 3a (FoxO3a) and increased catalase activity in proximal tubule cells. Augmented catalase activity decreased FLC-mediated production of hydrogen peroxide as well as the associated increase in High Mobility Group Box 1 (HMGB1) protein release and caspase-3 activity. Coincubation of cells with FLC and an allosteric activator of Sirtuin 1 (SIRT1) was also sufficient to increase catalase activity and promote similar cytoprotective effects. Our studies confirmed that the mechanism of downregulation of catalase by FLC involved deactivation of FoxO3a and inhibition of SIRT1. Mechanistic understanding of catalase regulation allows for future treatments that target pathways that increase catalase in the setting of proximal tubule injury from FLC.

Role of TRPA1 expressed in bone tissue and the antinociceptive effect of the TRPA1 antagonist repeated administration in a breast cancer pain model

AimsBreast cancer-induced chronic pain is usually treated with opioids, but these compounds cause various adverse effects. Transient receptor potential ankyrin 1 (TRPA1) is involved in cancer pain; also, endogenous TRPA1 agonists are associated with cancer pain development. The aim of this study was to observe the antinociceptive effect of a repeated-dose TRPA1 antagonist administration and the production of endogenous TRPA1 agonists and TRPA1 expression in bone tissue in a model of breast cancer pain in mice. Second, we used a sequence reading archive (SRA) strategy to observe the presence of this channel in the mouse bone and in mouse bone cell lines. Main methodsWe used BALB/c mice for experiments. The animals were subjected to the tumor cell inoculation (4 T1 strain). HC-030031 (a TRPA1 antagonist) treatment was done from day 11 to day 20 after tumor inoculation. TRPA1 expression and biochemical tests of oxidative stress were performed in the bone of mice (femur). SRA strategy was used to detect the TRPA1 presence. Key findingsRepeated treatment with the TRPA1 antagonist produced an antinociceptive effect. There was an increase in hydrogen peroxide levels, NADPH oxidase and superoxide dismutase activities, but the expression of TRPA1 in the bone tissue was not altered. SRA did not show TRPA1 residual transcription in the osteoblast and osteoclast cell lines, as well as for mice cranial tissue and in mouse osteoclast precursors. SignificanceThe TRPA1 receptor is a potential target for the development of new painkillers for the treatment of bone cancer pain.

Impaired F1Fo-ATP-Synthase Dimerization Leads to the Induction of Cyclophilin D-Mediated Autophagy-Dependent Cell Death and Accelerated Aging.

Mitochondrial F1Fo-ATP-synthase dimers play a critical role in shaping and maintenance of mitochondrial ultrastructure. Previous studies have revealed that ablation of the F1Fo-ATP-synthase assembly factor PaATPE of the ascomycete Podospora anserina strongly affects cristae formation, increases hydrogen peroxide levels, impairs mitochondrial function and leads to premature cell death. In the present study, we investigated the underlying mechanistic basis. Compared to the wild type, we observed a slight increase in non-selective and a pronounced increase in mitophagy, the selective vacuolar degradation of mitochondria. This effect depends on the availability of functional cyclophilin D (PaCYPD), the regulator of the mitochondrial permeability transition pore (mPTP). Simultaneous deletion of PaAtpe and PaAtg1, encoding a key component of the autophagy machinery or of PaCypD, led to a reduction of mitophagy and a partial restoration of the wild-type specific lifespan. The same effect was observed in the PaAtpe deletion strain after inhibition of PaCYPD by its specific inhibitor, cyclosporin A. Overall, our data identify autophagy-dependent cell death (ADCD) as part of the cellular response to impaired F1Fo-ATP-synthase dimerization, and emphasize the crucial role of functional mitochondria in aging.

Eugenol attenuates TiO2 nanoparticles-induced oxidative damage, biochemical toxicity and DNA damage in Wistar rats: an in vivo study.

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in food, edible dyes, and other commercial products. Human exposure to TiO2 NPs has raised concerns regarding their toxic potential. Various studies have evaluated the TiO2 NPs-induced toxicity, oxidative damage to the cellular components, and genotoxicity. In the present study, we examined whether co-treatment with the dietary antioxidant eugenol can attenuate or protect against TiO2 NPs-induced toxicity. We exposed the adult male Wistar rats to TiO2 NPs (150 mg/kg body weight) by intraperitoneal injection (i.p.) either alone or as co-treatment with eugenol (1-10 mg/kg body weight) once a day for 14 days. The untreated rats were supplied saline and served as control. Titanium (Ti) accumulation in various tissues was analyzed by inductively coupled plasma mass spectrometry. Serum levels of liver and kidney biomarkers and oxidative stress markers in the liver, kidney, and spleen were determined. A significant increase in hydrogen peroxide level confirmed that oxidative stress occurred in these tissues. TiO2 NPs induced oxidation of lipids, and decreased glutathione level and antioxidant enzyme activity in the kidney, liver, and spleen of treated rats. TiO2 NPs also increased the serum levels of alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, albumin, and total cholesterol and decreased the blood urea nitrogen, uric acid, and total bilirubin in serum, which indicates oxidative damage to the liver and kidney. In eugenol and TiO2 NPs co-treated rats, all these changes were mitigated. Single-cell gel electrophoresis (comet assay) of lymphocytes showed longer comet tail length in TiO2 NPs-treated groups, indicating DNA damage while tail length was reduced in eugenol and TiO2 NPs co-treated groups. Thus, it seems that eugenol can be used as a chemoprotective agent against TiO2 NPs-induced toxicity.

Hydroalcoholic extract of Pfaffia glomerata alters the organization of the seminiferous tubules by modulating the oxidative state and the microstructural reorganization of the mice testes

Ethnopharmacological usagesLeaves and roots of Pfaffia glomerata areused as aphrodisiacs, tranquilizers and antirheumatics. Due to the lack of experimental scientific data, studies are necessary to identify its medicinal properties. AimsThe present study aimed to evaluate the effect of hydroalcoholic root extract of P. glomerata (Brazilian ginseng extract - BGE) on testicular parenchyma, and evaluate possible harmful effects through testicular oxidative stress analysis. Materials and methodsAdult mice were divided into 6 groups: control (water), sildenafil citrate, BGE (100, 200 and 400 mg/kg/day), and BGE (200 mg/kg every three days). ResultsThe treatment reduced the volumetric proportions of seminiferous tubules and epithelium, the number of Sertoli cells, and increased hydrogen peroxide levels, without affecting sperm production. It also caused cell death and changes in the frequency of stages of the seminiferous epithelium cycles. The 100 mg/kg dose responds in a similar way to sildenafil citrate, promoting changes in the gonadal structure, but with efficient response to contain the damage. ConclusionsDoses of 200 mg/kg, continuous or discontinuous, induced an increase in testicular nitric oxide, as well as sildenafil citrate, showing be efficient as aphrodisiac, but promotes cell death regardless of the form of administration.

Separate and combined effects of glyphosate and copper on growth and antioxidative enzymes in Salvinia natans (L.) All

The coexistence of glyphosate and copper is widely found in bodies of water and terrestrial ecosystems due to widespread application of herbicides and heavy metal. However, their joint ecotoxicological risks in aquatic environments remain unknown. The experiment investigated the individual and combined effects of glyphosate and copper on the growth and physiological response in Salvinia natans (L.) All. The results showed that their joint toxicity is related to concentration. Antagonistic effects were induced when plants were exposed to low concentrations of glyphosate and copper (≤1 + 0.2 mg l−1). Synergistic effects were elicited at higher doses (≥5 + 1 mg l−1). In addition, increased hydrogen peroxide levels indicated the occurrence of oxidative stress at individual or combined exposures. To cope with oxidative stress, S. natans can activate the antioxidant defense systems, including increased superoxide dismutase and changes in peroxidase, ascorbate peroxidase and catalase. High concentrations of combined pollution exceed the oxidative defense capabilities of plants, and therefore, malondialdehyde content increased significantly. Our results indicated that the ecotoxicity of glyphosate or copper may be exacerbated in aquatic environments and caused obvious damage to S. natans.

Acute renal toxicity of sodium chlorate: Redox imbalance, enhanced DNA damage, metabolic alterations and inhibition of brush border membrane enzymes in rats.

Sodium chlorate (NaClO3 ) is widely used in paper and pulp industries and as a non-selective herbicide. Humans can be exposed to NaClO3 through contaminated drinking water due to its improper and unchecked usage in industries and as herbicide. NaClO3 is also present as a major stable by-product in drinking water that has been disinfected with chlorine dioxide. In this study, we have investigated the effect of a single acute oral dose of NaClO3 on rat kidney. Adult male Wistar rats were divided into one control and four NaClO3 treated groups that were orally given different doses of NaClO3 and euthanized 24 hr after the treatment. Oral administration of NaClO3 resulted in increased hydrogen peroxide levels, lipid, and protein oxidation while thiol and glutathione content and activities of brush border membrane enzymes were decreased in kidney in a NaClO3 dose-dependent manner. Significant alterations in the activities of enzymes involved in carbohydrate metabolism and antioxidant defense were also observed. Administration of NaClO3 induced DNA fragmentation and increased DNA-protein cross-linking. Histological studies showed marked damage in kidney from NaClO3 treated animals. These results strongly suggest that NaClO3 induces nephrotoxicity via redox imbalance that results in DNA and membrane damage, metabolic alterations and brush border membrane enzyme dysfunction.

Cell cycle regulation in different leaves of Arabidopsis thaliana plants grown under control and cadmium-exposed conditions

Cadmium (Cd) is well known to inhibit vegetative plant growth. However, knowledge regarding its influence on the cell cycle is scarce and mainly limited to cell cultures and root tissue. Therefore, the main aim of this study was to investigate the effects of Cd exposure on cell division and endoreduplication in Arabidopsis thaliana leaves. In order to do so, we first investigated whether different leaves of the same rosette harvested at one time point (i.e. leaf position) could be used as an alternative for leaf age when investigating the cell cycle. To this end, wild-type A. thaliana plants were grown hydroponically with or without the addition of 5 μM CdSO4. Leaf growth and development, cell division, endoreduplication and the expression of cell cycle-related genes were investigated in separate leaves. The results show that different leaf positions constitute a developmental series that can be used to deduce the development of a single leaf over time. Furthermore, our data indicate that the concentration of nuclei in leaf extracts measured via flow cytometry can be used as a proxy to determine the effects of stress factors on the extent of cell division in A. thaliana leaves, reducing the need to perform time consuming microscopic analyses. Finally, we show that Cd exposure significantly reduces cell number, cell size and nuclear DNA content, implying an inhibition of both cell division and endoreduplication. These effects accumulate over time and contribute to the Cd-induced disturbance of leaf growth and development. At the molecular and cellular level, Cd increases hydrogen peroxide levels and induces the expression of marker genes for oxidative stress and DNA damage and genes encoding CDK inhibitors of the SIAMESE-RELATED family, suggesting that the Cd-induced inhibition of cell cycle progression is intertwined with oxidative stress and subsequent DNA damage.