Increased Lipid Hydroperoxide Levels Research Articles

GPX4 allosteric activators inhibit ferroptosis and exert myocardial protection in doxorubicin-induced myocardial injury mouse model

Ferroptosis is a unique type of non-apoptotic form of cell death characterized by increased lipid hydroperoxide levels. It has relevance for a number of pathological conditions including multiple organ injuries and degenerative diseases. GPX4 plays an important role in ferroptosis by repairing lipid hydroperoxides. Based on the reported allosteric sites, we obtained the GPX4 allosteric activator hit compound A9 through virtual screening. A9 can bind to GPX4 and prevent RSL3-induced lipid peroxidation production in HT-1080 cells. In addition, A9 can specifically rescue erastin-induced cell death. Further chemical modification and structure-activity relationship studies afforded the optimized compound C3. C3 showed the activity of alleviating myocardial injury in the doxorubicin-induced myocardial injury mouse model. This study demonstrated that inhibiting ferroptosis by activating GPX4 is expected to be a potential solution to treat myocardial injury.

Effects of vitamin D administration on nociception and spinal cord pro-oxidant and antioxidant markers in a rat model of neuropathic pain.

Reactive oxygen species (ROS) are involved in neuropathic pain, a complicated condition after nerve tissue lesion. Vitamin D appears to improve symptoms of pain and exhibits antioxidant properties. We investigated the effects of oral administration of vitamin D3, the active form of vitamin D, on nociception, the sciatic functional index (SFI), and spinal cord pro-oxidant and antioxidant markers in rats with chronic constriction injury (CCI) of the sciatic nerve, a model of neuropathic pain. Vitamin D3 (500 IU/kg per day) attenuated the CCI-induced decrease in mechanical withdrawal threshold and thermal withdrawal latency (indicators of antinociception) and SFI. The vitamin prevented increased lipid hydroperoxide levels in injured sciatic nerve without change to total antioxidant capacity (TAC). Vitamin D3 prevented increased lipid hydroperoxide, superoxide anion generation (SAG), and hydrogen peroxide (H2O2) levels in the spinal cord, which were found in rats without treatment at 7 and 28 days post-CCI. A significant negative correlation was found between mechanical threshold and SAG and between mechanical threshold and H2O2 at day 7. Vitamin D3 also prevented decreased spinal cord total thiols content. There was an increase in TAC in the spinal cord of vitamin-treated CCI rats, compared to CCI rats without treatment only at 28 days. No significant changes were found in body weight and blood parameters of hepatic and renal function. These findings demonstrated, for first time, that vitamin D modulated pro-oxidant and antioxidant markers in the spinal cord. Since antinociception occurred in parallel with oxidative changes in the spinal cord, the oxidative changes may have contributed to vitamin D-induced antinociception.

Remote organs respond differently to curcumin treatment after intestinal ischemia/reperfusion injury

We aimed investigate the effects of 45 min of ischemia followed by 72 h of intestinal reperfusion (IR) in the ileum, liver, lungs, and kidneys in Wistar rats and the responses of these organs to curcumin treatment. Ischemia was induced by occluding the superior mesenteric artery. Rats were treated orally with 40 mg/kg curcumin. We analyzed oxidative stress and inflammation in the ileum, liver, lungs, and kidneys. Intestinal IR led to a reduction of reduced glutathione levels in the intestine, lungs, and kidneys and increased lipid hydroperoxide levels in all organs. An increase in the enzymatic activity of catalase was observed in all organs, and an increase in superoxide dismutase activity was observed in the ileum and lungs. Glutathione s-transferase levels increased only in the kidneys. Myeloperoxidase increased in all four organs, and n-acetyl-glycosaminidase increased only in the ileum and lungs. Curcumin prevented all of the changes in the ileum and liver. In the lungs, curcumin had no effect on n-acetyl-glycosaminidase. Curcumin did not prevent the changes in reduced glutathione, lipid hydroperoxides, or myeloperoxidase in the kidneys. Intestinal IR caused oxidative stress and inflammation in the ileum, lungs, and kidneys and to a lesser degree in the liver. Because of its systemic distribution, curcumin prevented changes mainly in the ileum, lungs, and liver and to a lesser degree in the kidneys.

Effects of a glyphosate-based herbicide on survival and oxidative status of a non-target herbivore, the Colorado potato beetle (Leptinotarsa decemlineata)

Glyphosate is the globally most used herbicide against a wide range of weeds. Glyphosate has been considered safe to animals as it mainly targets physiological pathways in plants. However, recent toxicological studies have revealed that glyphosate can cause various toxic effects also on animals. In this study, we investigated the direct toxic effects of a glyphosate-based herbicide (GBH, Roundup® Bio) on 1) survival and 2) oxidative status of a non-target herbivore by using Colorado potato beetles (Leptinotarsa decemlineata), originating from Poland and USA, as model species. Larvae were randomly divided into three groups: 1) high concentration (100% Roundup Bio, 360 g/l), 2) low concentration (1.5% Roundup Bio) and 3) control group (water). Larvae were exposed to Roundup for different time periods: 2 h, 24 h, 48 h, 72 h and 96 h. Larval survival decreased in the group treated with high concentration of GBH compared to controls, whereas the low concentration group did not differ from the control group. GBH treatment had no association with oxidative status biomarkers (i.e. catalase, superoxide dismutase, glutathione-S-transferase, glutathione and glutathione related enzymes), but increased lipid hydroperoxide levels after 2 h exposure, suggesting increased oxidative damage soon after the exposure. Larvae of different origin also differed in their oxidative status, indicating population-dependent differences in antioxidant defence system. Environmentally relevant concentrations of GBH are not likely to affect larval survival, but high concentrations can reduce survival and increase oxidative damage of non-target herbivores. Also, populations of different origin and pesticide usage history can differ in their tolerance to GBH.

Cell growth potential drives ferroptosis susceptibility in rhabdomyosarcoma and myoblast cell lines.

Ferroptosis is a programmed form of iron-dependent cell death caused by lipid hydroperoxide accumulation, which can be prevented by glutathione peroxidase 4 (GPx4) activity. Here we investigated the effects of ferroptosis inducers called erastin and RSL3, which act by glutathione depletion and GPx4 inactivation, respectively, on muscle-derived cell lines of embryonal and alveolar rhabdomyosarcoma (RMS), and mouse normal skeletal C2C12 myoblasts. Myogenic lines were exposed to stepwise increasing concentrations of ferroptosis inducers either alone or in combination with iron supplementation, iron chelating agents (bathophenanthrolinedisulfonic acid, BPS), antioxidant molecules (glutathione, N-acetylcysteine), lipid peroxidation inhibitors (ferrostatin-1), and chemotherapeutic agents (doxorubicin and actinomycin D). Drug susceptibility was quantified by measuring cell viability, proliferation and differentiation via neutral red assay, crystal violet assay and Giemsa staining, respectively. The detection of lipid hydroperoxide and protein levels was performed by immunofluorescence and Western blot analysis, respectively. Erastin and RSL3 increased lipid hydroperoxide levels preferentially in the embryonal U57810 and myoblast C2C12 lines, leading to ferroptosis that was accentuated by iron supplementation or prevented by co-treatment with BPS, glutathione, N-acetylcysteine and ferrostatin-1. The inhibition of extracellular regulated kinases (ERK) pathway prevented ferroptosis in U57810 and C2C12 cells, whereas its increased activation in the embryonal RD cells mediated by caveolin-1 (Cav-1) overexpression led to augmented ferroptosis susceptibility. Finally, we observed the combination of erastin or RSL3 with chemotherapeutic doxorubicin and actinomycin D agents to be effective in increasing cell death in all RMS lines. Erastin and RSL3 triggerferroptosis in highly proliferatingmyogenic lines through a ERK pathway-dependent fashion.

Spermidine rescues proximal tubular cells from oxidative stress and necrosis after ischemic acute kidney injury.

Kidney ischemia and reperfusion injury (IRI) is associated with a high mortality rate, which is attributed to tubular oxidative stress and necrosis; however, an effective approach to limit IRI remains elusive. Spermidine, a naturally occurring polyamine, protects yeast cells against aging through the inhibition of oxidative stress and necrosis. In the present study, spermidine supplementation markedly attenuated increases in plasma creatinine concentration and tubular injury score after IRI. In addition, exogenous spermidine potently inhibited oxidative stress, especially lipid peroxidation after IRI in kidneys and exposure to hydrogen peroxide in kidney proximal tubular cells, suppressing plasma membrane disruption and necrosis. Consistent with spermidine supplementation, upregulation of ornithine decarboxylase (ODC) in human kidney proximal tubular cells significantly diminished lipid peroxidation and necrosis induced by hydrogen peroxide-induced injury. Conversely, ODC deficiency significantly enhanced lipid peroxidation and necrosis after exposure to hydrogen peroxide. Finally, small interfering RNA-mediated ODC inhibition induced functional and histological damage in kidneys as well as it increased lipid hydroperoxide levels after IRI. In conclusion, these data suggest that spermidine level determines kidney proximal tubular damage through oxidative stress and necrosis induced by IRI, and this finding provides a novel target for prevention of tubular damage induced by IRI.

Acetaminophen intoxication is associated with decreased serum paraoxonase and arylesterase activities and increased lipid hydroperoxide levels

Acetaminophen is at present one of the most commonly used analgesics and antipyretics. Recent evidence has suggested that oxidative stress is involved in the mechanism of acetaminophen intoxication. Paraoxonase-1 (PON1) plays an important role as an endogenous free-radical scavenging molecule. The aim of this study was to evaluate the influence of serum PON1 activity and oxidative stress in patients with acetaminophen intoxication. A total of 20 patients with acetaminophen intoxication and 25 healthy controls were enrolled. Serum total antioxidant capacity (TAC), lipid hydroperoxide (LOOH) levels, and paraoxonase and arylesterase activities were measured spectrophotometrically. The serum TAC levels and the paraoxonase and arylesterase activities were significantly lower in patients with acetaminophen intoxication compared with controls (all, p < 0.001), while the serum LOOH levels were significantly higher (p < 0.001). Our results suggest that decreased PON1 activity seems to be associated with increased oxidative stress in patients with acetaminophen intoxication. Measuring serum PON1 activity may be useful in assessing the development of toxicity risk in acetaminophen toxicity. It would be useful to recommend vitamins with antioxidant effects such as vitamins C and E along with medical treatments.

Reduced PON1 enzymatic activity and increased lipid hydroperoxide levels that point out oxidative stress in generalized anxiety disorder

In recent years, there has been an increasing focus on generalized anxiety disorder (GAD) which is one of the most prevalent mental disorders in general population. Psychological, genetic, neurobiological, and neurochemical factors are believed to play role in the etiopathogenesis of GAD. The role of oxidative stress, as a neurochemical cause, in various anxiety disorders has been studied in recent years; however, it has not been thoroughly studied in GAD, yet. In this paper, we aimed to evaluate the serum levels of lipid hydroperoxide (LOOH), paraoxonase, and arylesterase in GAD patients without any co-morbid psychiatric disorders and investigate their diagnostic performance.Blood samples were collected from 40 GAD patients and 40 healthy control subjects to measure their serum LOOH levels, arylesterase and paraoxonase activities. Obtained results have been compared between groups and receiver operating characteristic (ROC) curve has been drawn for diagnostic performance of measured biochemical markers. Positive and negative predictive values have been estimated where appropriate.Mean LOOH level of the GAD patients was significantly higher than that of control subjects (t=−5.49, p<0.001), whereas, mean paraoxonase activity was lower in these patients (t=3.056, p=0.03). GAD could be predicted for LOOH level over 7.740μmol/l with 92.5% positive predictive value and 92% negative predictive value.Increased LOOH level and decreased paraoxonase activity of GAD patients may suggest increased lipid peroxidation and oxidative stress in these patients. LOOH levels may be a state marker for diagnosing GAD.

Serum paraoxonase and arylesterase activities in iron deficiency anemia during pregnancy

To investigate serum paraoxonase and arylesterase activities, and lipid hydroperoxide levels in pregnant women with iron deficiency anemia. Materials and methods: Paraoxonase and arylesterase activities, and lipid hydroperoxide levels were assessed for pregnant women with iron deficiency anemia (n = 50) and controls (n = 70). Serum basal and salt-stimulated paraoxonase, and arylesterase activities were measured spectrophotometrically. The lipid hydroperoxide levels were measured by ferrous ion oxidation xylenol orange assay. In addition, lipid parameters were determined by routine laboratory methods. Results: Basal and salt-stimulated paraoxonase, and arylesterase activities were significantly lower (P = 0.026, P = 0.031, and P = 0.018, respectively) in pregnant women with iron deficiency anemia when compared to the controls, while lipid hydroperoxide levels were significantly higher (P = 0.004). A significant positive correlation was found between paraoxonase activity and hemoglobin levels (r = 0.329, P = 0.020), while there was inverse correlation between lipid hydroperoxide and hemoglobin levels (r = -0.457, P = 0.001). Among iron deficiency anemia, serum paraoxonase activity was inversely correlated with lipid hydroperoxide levels (r = -0.535, P < 0.001). Conclusion: The findings of the present study have shown that diminished serum paraoxonase and arylesterase activities, and increased lipid hydroperoxide levels may play a role in the early pathogenesis of atherosclerotic heart disease in pregnant women with iron deficiency anemia.

Oxidant Stress in Healthy Normal‐weight, Overweight, and Obese Individuals

This study was undertaken to investigate the association among BMI and lipid hydroperoxide (LH), total antioxidant status (TAS), superoxide dismutase (SOD), and reduced glutathione (GSH). Ninety (n = 90) healthy males and females (n = 23/67) (29 normal weight (BMI: 22.74 +/- 0.25 kg/m(2)), 36 overweight (BMI: 27.18 +/- 0.23 kg/m(2)), and 25 obese (33.78 +/- 0.48 kg/m(2))) participated in the study. Data collected included anthropometric measures, fasting blood glucose, lipid profile, LH, TAS, and enzymatic antioxidants (SOD, and reduced GSH). The results of the study showed that obese individuals had significantly increased LH levels compared to normal-weight individuals (obese vs. normal weight (0.88 +/- 0.05 vs. 0.67 +/- 0.03 micromol/l, P < 0.01)) but the increased levels were not significantly different when compared to the overweight group (obese vs. overweight (0.88 +/- 0.05 vs. 0.79 +/- 0.05 micromol/l)). No other consistent significant differences in TAS, SOD, and GSH were identified between groups. This study concluded that only obesity and not moderate overweight elevates LH levels. Furthermore, the levels of TAS, SOD, and GSH in obesity do not explain the increased LH levels observed in obesity.

Lipid Hydroperoxide Stimulates Leukocyte–Endothelium Interaction in the Retinal Microcirculation

Leukocyte dynamics were evaluatyed in vivo in rat retinal microcirculation following exposure to lipid hydroperoxide (LHP) in the vitreous.Various amounts (1, 5, 10 or 100 μg) of LHP (18:2) dissolved in 5 μl of sodium borate buffer (SBB, 0.02M) were injected into the vitreous of Brown-Norway rats. As a comparative study, 10 μg of linoleic acid (LA) dissolved in 5 μl of SBB was injected in the same way. Rats that did not undergo injection were evaluated as un-treated. At 2 to 48 hr after LHP exposure, the following were examined: (1) the flux of rolling leukocytes along the major retinal veins, (2) the number of leukocytes that accumulated in the retinal microvasculature using acridine orange digital fluorography and (3) the diameter of major retinal vessels.In the LHP-treated eyes, leukocyte rolling along the major retinal veins was observed and the number increased in a dose-dependent manner ( 1 to 10 μg). The flux of rolling leukocytes peaked at 6 hr after LHP (10–100 μg) injection. No rolling leukocytes were observed in LA-treated or un-treated eyes. The number of accumulated leukocytes started to increase at 4 hr and peaked at 24 hr after LHP (10 μg) injection. This number was significantly higher than that in LA-treated and un-treated eyes. Venous dilation was seen from 4 hr after LHP (10 μg) injection and became significant at 6 and 24 hr as compared with LA-treated and un-treated eyes..The results indicate that increased LHP levels in the vitreous due to oxidative stress enhance leukocyte–enothelium interaction in the retinal microcirculation.

Total antioxidant capacity is reduced in Crohn’s disease

In previous work we identified depletion of the micronutrient glutathione in colon from patients with Crohn’s disease. Since there are several linked intestinal antioxidant systems, we hypothesized that there would be global alteration of the tissue content of antioxidants in Crohn’s disease. We therefore examined total antioxidant capacity and lipid hydroperoxide levels in colon from non-obstructed neoplasia and acquired megacolon as non-inflammatory controls and in colon from Crohn’s disease. Total antioxidant capacity in the mucosal-submucosal layer was decreased in Crohn’s disease (pANOVA = .02) and there was a strong trend toward decreased total antioxidant capacity in the muscularis externa layer from Crohn’s disease ( p = .06). There were trends toward increased lipid hydroperoxide levels in Crohn’s disease. This study supports the presence of a generalized consumption of tissue antioxidants in Crohn’s disease. The clinical response to nutritional therapy in patients with Crohn’s disease may be related to repletion of tissue antioxidants.

α‐tocopherol and γ‐tocopherol attenuate ethanol‐induced changes in membrane fatty acid composition in embryonic chick brains

Background This project investigated whether or not EtOH-induced reductions in the levels of long-chain polyunsaturated membrane fatty acids could be attenuated by exogenous exposure to either α-tocopherol, γ-tocopherol, or diallyl sulfide (DAS). Methods At 0 days of development, fertile chicken eggs were injected with a single dose of either saline supplemented with various concentrations of EtOH, α- or γ-tocopherol and EtOH, or DAS and EtOH. At 18 days of development, brains were isolated and subjected to membrane analyses. Results When exposed to EtOH, concentrations ranging from 0–60.50 μm/Kg egg, dose-dependent decreases in the levels of brain 18:0, 18:1 (n-9), 18:2 (n-6), 18:3 (n-3), and 20:4 (n-6) were observed. These ethanol–induced changes in membrane fatty acid composition correlated with ethanol-induced reductions in brain mass, brain protein levels, acetylcholine esterase (AChE) activities and correlated with increased lipid hydroperoxide levels. Exposure to either 2.5 μm α-tocopherol/Kg egg and 6.050 mm EtOH/Kg egg, or 2.5 μm α-tocopherol/ Kg egg and 6.050 mm EtOH/Kg egg attenuated EtOH-induced changes in membrane fatty acid composition, brain mass, brain protein levels, AChE activities, and lipid hydroperoxide levels. Embryonic exposure to the cytochrome p450-2E1 inhibitor, diallyl sulfide (DAS), also attenuated EtOH-induced decreases in long-chain, unsaturated membrane fatty acids. However, embryonic exposure to DAS promoted abnormally low brain mass. Conclusion EtOH-induced reductions in the levels of brain long-chain polyunsaturated fatty acid are caused by lipid peroxidation. Teratology 62:26–35, 2000. © 2000 Wiley-Liss, Inc.