Isoflurane preconditioning protects against renal ischemia/reperfusion injury in diabetes via activation of the Brg1/Nrf2/HO-1 signaling pathway.

PURPOSE: To examine whether isoflurane preconditioning (IsoP) has a protective effect against renal ischemia/reperfusion injury (I/RI) in diabetic conditions and to further clarify the underlying mechanisms. METHODS: Control and streptozotocin-induced diabetic rats were randomly assigned to five groups, as follows: normal sham, normal I/R, diabetic sham, diabetic I/R, and diabetic I/R + isoflurane. Renal I/RI was induced by clamping renal pedicle for 45 min followed by reperfusion for 24 h. IsoP was achieved by exposing the rats to 2% isoflurane for 30 min before vascular occlusion. Kidneys and blood were collected after reperfusion for further analysis. Renal histology, blood urea nitrogen, serum creatinine, oxidative stress, inflammatory cytokines, and renal cell apoptosis were assessed. Furthermore, the expression of brahma related gene 1 (Brg1), nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and nuclear factor-κB (NF-κB) were determined. RESULTS: Compared with control, diabetic rats undergoing I/R presented more severe renal injury, oxidative stress, inflammatory reaction, and apoptosis with the impairment of Brg1/Nrf2/HO-1 signaling. All these alterations were significantly attenuated by pretreatment with isoflurane. CONCLUSIONS: These findings suggest that isoflurane could alleviate renal I/RI in diabetes, possibly through improving Brg1/Nrf2/HO-1 signaling.

Ozone therapy mitigates parthanatos after ischemic stroke.

BACKGROUND: Stroke is a leading cause of death worldwide, with oxidative stress and calcium overload playing significant roles in the pathophysiology of the disease. Ozone, renowned for its potent antioxidant properties, is commonly employed as an adjuvant therapy in clinical settings. Nevertheless, it remains unclear whether ozone therapy on parthanatos in cerebral ischemia-reperfusion injury (CIRI). This study aims to investigate the impact of ozone therapy on reducing parthanatos during CIRI and to elucidate the underlying mechanism. METHODS: Hydrogen peroxide (H2O2) was utilized to mimic the generation of reactive oxygen species (ROS) in SH-SY5Y cell reperfusion injury in vitro, and an in vivo ischemic stroke model was established. Ozone saline was introduced for co-culture or intravenously administered to mice. Apoptosis and oxidative stress were assessed using flow cytometry and immunofluorescence. Western blotting was utilized to examine the expression of parthanatos signature proteins. The mechanism by which ozone inhibits parthanatos was elucidated through inhibiting PPARg or Nrf2 activity. RESULTS: The findings demonstrated that ozone mitigated H2O2-induced parthanatos by either upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) or activating peroxisome proliferator-activated receptorg (PPARg). Furthermore, through the use of calcium chelators and ROS inhibitors, it was discovered that ROS directly induced parthanatos and facilitated intracellular calcium elevation. Notably, a malignant feedback loop between ROS and calcium was identified, further amplifying the induction of parthanatos. Ozone therapy exhibited its efficacy by increasing PPARg activity or enhancing the Nrf2 translation, thereby inhibiting ROS production induced by H2O2. Concurrently, our study demonstrated that ozone treatment markedly inhibited parthanatos in stroke-afflicted mice. Additionally, ozone therapy demonstrated significant neuroprotective effects on cortical neurons, effectively suppressing parthanatos. CONCLUSIONS: These findings contribute valuable insights into the potential of ozone therapy as a therapeutic strategy for reducing parthanatos during CIRI, highlighting its impact on key molecular pathways associated with oxidative stress and calcium regulation.

Endothelin-1 down-regulates nuclear factor erythroid 2-related factor-2 and contributes to perivascular adipose tissue dysfunction in obesity.

Perivascular adipose tissue (PVAT) negatively regulates vascular muscle contraction. However, in the context of obesity, the PVAT releases vasoconstrictor substances that detrimentally affect vascular function. A pivotal player in this scenario is the peptide endothelin-1 (ET-1), which induces oxidative stress and disrupts vascular function. The present study postulates that obesity augments ET-1 production in the PVAT, decreases the function of the nuclear factor erythroid 2-related factor-2 (Nrf2) transcription factor, further increasing reactive oxygen species (ROS) generation, culminating in PVAT dysfunction. Male C57BL/6 mice were fed either a standard or a high-fat diet for 16 weeks. Mice were also treated with saline or a daily dose of 100 mg·kg-1 of the ETA and ETB receptor antagonist Bosentan, for 7 days. Vascular function was evaluated in thoracic aortic rings, with and without PVAT. Mechanistic studies utilized PVAT from all groups and cultured WT-1 mouse brown adipocytes. PVAT from obese mice exhibited increased ET-1 production, increased ECE1 and ETA gene expression, loss of the anticontractile effect, as well as increased ROS production, decreased Nrf2 activity, and downregulated expression of Nrf2-targeted antioxidant genes. PVAT of obese mice also exhibited increased expression of Tyr216-phosphorylated-GSK3ß and KEAP1, but not BACH1 - negative Nrf2 regulators. Bosentan treatment reversed all these effects. Similarly, ET-1 increased ROS generation and decreased Nrf2 activity in brown adipocytes, events mitigated by BQ123 (ETA receptor antagonist). These findings place ET-1 as a major contributor to PVAT dysfunction in obesity and highlight that pharmacological control of ET-1 effects restores PVAT's cardiovascular protective role.

Protective function of albiflorin against ferroptosis in exhaustive exerciseinduced myocardial injury via the AKT/Nrf2/HO-1 signaling.

PURPOSE: It has been reported that exhaustive exercise (EE) causes myocyte injury, and eventually damages the function of the myocardia. Albiflorin (AF) has anti-inflammatory, antioxidant, and anti-apoptosis effects. In this study, we determined whether AF could mitigate the EE-induced myocardial injury and research the potential mechanisms. METHODS: The rat model of EE was built by forced treadmill running method. Rats were intraperitoneally injected with AF before EE once daily for one week. The relative factors levels were examined by commercial kits. The apoptosis was appraised using a TdT-mediated dUTP nick end labeling assay kit. The ACSL4, GPX4, Nrf2, pAKT/AKT, and HO-1 contents were assessed by western blot. RESULTS: AF lessened EE-induced cardiac myocytes ischemic/hypoxic injury and reduced the contents of myocardial injury biomarkers in the serum. AF lessened EE-induced cardiac myocyte apoptosis, inflammatory response, oxidative stress, and ferroptosis in myocardial tissues. However, the influences of AF were overturned by the co-treatment of AF and LY294002. AF activated the AKT/Nrf2/HO-1 signaling pathway in myocardial tissues in vivo. CONCLUSIONS: AF could curb cardiac myocytes ferroptosis, thus diminishing the EE-induced myocardial injury through activating the AKT/Nrf2/HO-1 cascade.

Nebulized Glutathione as a Key Antioxidant for the Treatment of Oxidative Stress in Neurodegenerative Conditions.

Glutathione (GSH), a tripeptide synthesized intracellularly, serves as a pivotal antioxidant, neutralizing reactive oxygen species (ROS) and reactive nitrogen species (RNS) while maintaining redox homeostasis and detoxifying xenobiotics. Its potent antioxidant properties, particularly attributed to the sulfhydryl group (-SH) in cysteine, are crucial for cellular health across various organelles. The glutathione-glutathione disulfide (GSH-GSSG) cycle is facilitated by enzymes like glutathione peroxidase (GPx) and glutathione reductase (GR), thus aiding in detoxification processes and mitigating oxidative damage and inflammation. Mitochondria, being primary sources of reactive oxygen species, benefit significantly from GSH, which regulates metal homeostasis and supports autophagy, apoptosis, and ferroptosis, playing a fundamental role in neuroprotection. The vulnerability of the brain to oxidative stress underscores the importance of GSH in neurological disorders and regenerative medicine. Nebulization of glutathione presents a novel and promising approach to delivering this antioxidant directly to the central nervous system (CNS), potentially enhancing its bioavailability and therapeutic efficacy. This method may offer significant advantages in mitigating neurodegeneration by enhancing nuclear factor erythroid 2-related factor 2 (NRF2) pathway signaling and mitochondrial function, thereby providing direct neuroprotection. By addressing oxidative stress and its detrimental effects on neuronal health, nebulized GSH could play a crucial role in managing and potentially ameliorating conditions such as Parkinson's Disease (PD) and Alzheimer's Disease (AD). Further clinical research is warranted to elucidate the therapeutic potential of nebulized GSH in preserving mitochondrial health, enhancing CNS function, and combating neurodegenerative conditions, aiming to improve outcomes for individuals affected by brain diseases characterized by oxidative stress and neuroinflammation.

Iron chelation mitigates mitochondrial dysfunction and oxidative stress by enhancing nrf2-mediated antioxidant responses in the renal cortex of a murine model of type 2 diabetes.

Renal iron overload is a common complication of diabetes that leads to oxidative stress and mitochondrial dysfunction in the kidneys. This study investigated the effects of iron chelation using deferiprone on mitochondrial dysfunction and oxidative stress in the renal cortex of a murine model of type 2 diabetes. Diabetic rats were treated with deferiprone (50 mg/kg BW) for 16 weeks. Our results show that iron chelation with deferiprone significantly increased the nuclear accumulation of Nrf2, a transcription factor that regulates the expression of antioxidant enzymes. This led to enhanced antioxidant capacity, reduced production of reactive oxygen species, and improved mitochondrial bioenergetic function in diabetic rats. However, chronic iron chelation led to altered mitochondrial respiration and increased oxidative stress in non-diabetic rats. In conclusion, our findings suggest that iron chelation with deferiprone protects mitochondrial bioenergetics and mitigates oxidative stress in the renal cortex, involving the NRF2 pathway in type 2 diabetes.

Mechanisms Mediating the Combined Toxicity of Paraquat and Maneb in SH-SY5Y Neuroblastoma Cells.

Epidemiological and experimental studies have demonstrated that combined exposure to the pesticides paraquat (PQ) and maneb (MB) increases the risk of developing Parkinson's disease. However, the mechanisms mediating the toxicity induced by combined exposure to these pesticides are not well understood. The aim of this study was to investigate the mechanism(s) of neurotoxicity induced by exposure to the pesticides PQ and MB isolated or in association (PQ + MB) in SH-SY5Y neuroblastoma cells. PQ + MB exposure for 24 and 48 h decreased cell viability and disrupted cell membrane integrity. In addition, PQ + MB exposure for 12 h decreased the mitochondrial membrane potential. PQ alone increased reactive oxygen species (ROS) and superoxide anion generation and decreased the activity of mitochondrial complexes I and II at 12 h of exposure. MB alone increased ROS generation and depleted intracellular glutathione (GSH) within 6 h of exposure. In contrast, MB exposure for 12 h increased the GSH levels, the glutamate cysteine ligase (GCL, the rate-limiting enzyme in the GSH synthesis pathway) activity, and increased nuclear Nrf2 staining. Pretreatment with buthionine sulfoximine (BSO, a GCL inhibitor) abolished the MB-mediated GSH increase, indicating that MB increases GSH synthesis by upregulating GCL, probably by the activation of the Nrf2/ARE pathway. BSO pretreatment, which did not modify cell viability per se, rendered cells more sensitive to MB-induced toxicity. In contrast, treatment with the antioxidant N-acetylcysteine protected cells from MB-induced toxicity. These findings show that the combined exposure of SH-SY5Y cells to PQ and MB induced a cytotoxic effect higher than that observed when cells were subjected to individual exposures. Such a higher effect seems to be related to additive toxic events resulting from PQ and MB exposures. Thus, our study contributes to a better understanding of the toxicity of PQ and MB in combined exposures.

Photobiomodulation improves cell survival and death parameters in cardiomyocytes exposed to hypoxia/reoxygenation.

INTRODUCTION: Cardiovascular diseases are the leading cause of morbidity and mortality worldwide. Ischemic heart disease is one of the most harmful conditions to cellular structure and function. After reperfusion treatment, a spectrum of adverse effects becomes evident, encompassing altered cell viability, heightened oxidative stress, activated autophagy, and increased apoptosis. Photobiomodulation (PBM) has been utilized in experimental models of cardiac hypoxia to enhance mitochondrial response and ameliorate biochemical changes in injured tissue. However, the effects of PBM on cultured cardiomyocytes subjected to hypoxia/reoxygenation are not yet well established. METHOD: H9C2 cardiomyocytes were exposed to hypoxia with concentrations of 300 µM CoCl2 for 24 h, followed by 16 h of reoxygenation through incubation in a normoxic medium. Treatment was conducted using GaAIAs Laser (850 nm) after hypoxia at an intensity of 1 J/cm2. Cells were divided into three groups: Group CT (cells maintained under normoxic conditions), Group HR (cells maintained in hypoxia and reoxygenation conditions without treatment), Group HR + PBM (cells maintained in hypoxia and reoxygenation conditions that underwent PBM treatment). Cell viability was analyzed using MTT, and protein expression was assessed by western blot. One-way ANOVA with the Tukey post hoc test was used for data analysis. Differences were significant when p < 0.05. RESULTS: PBM at an intensity of 1 J/cm2 mitigated the alterations in cell survival caused by hypoxia/reoxygenation. Additionally, it significantly increased the expression of proteins Nrf2, HSP70, mTOR, LC3II, LC3II/I, and Caspase-9, while reducing the expression of PGC-1α, SOD2, xanthine oxidase, Beclin-1, LC3I, and Bax. CONCLUSION: PBM at intensities of 1 J/cm2 reverses the changes related to oxidative stress, mitochondrial biogenesis, autophagy, and apoptosis caused by hypoxia and reoxygenation in a culture of cardiomyocytes.

Keap1/Nrf2 signaling pathway participating in the progression of epilepsy via regulation of oxidative stress and ferroptosis in neurons.

OBJECTIVE: This study aims to analyze the relationship between the Kelch-like ECH-associated protein 1 (Keap1)/Nuclear factor-erythroid 2-related factor 2 (Nrf2) and Epilepsy (EP), as well as its mechanism of action. METHODS: Thirty Wistar rats were divided into a control group (without treatment), a model group (EP modeling), and an inhibition group (EP modeling + intervention by Keap1/Nrf2 signaling pathway inhibitor ATRA) and subject to Morris water maze experiment. Then, the expression of Oxidative Stress (OS) markers, ferroptosis-associated proteins and Keap1/Nrf2 pathway in rat hippocampus was measured. In addition, rat hippocampal neuronal cell HT22 was purchased and treated accordingly based on the results of grouping, and cell proliferation and apoptosis in the three groups were determined. RESULTS: Compared with rats in the model group, those in the inhibition group showed shorter escape latency and an increased number of platform crossings (p < 0.05). Significant OS and neuron ferroptosis, increased apoptosis rate, elevated Keap1 expression, and decreased Nrf2 expression were observed in the model group compared to the control group (p < 0.05). The inhibition group exhibited notably improved OS and ferroptosis, as well as enhanced neuronal viability (p < 0.05). CONCLUSION: Inhibition of the Keap1/Nrf2 pathway can reverse the OS and neuron viability in EP rats.

Antiviral, anti-inflammatory and antioxidant effects of curcumin and curcuminoids in SH-SY5Y cells infected by SARS-CoV-2.

COVID-19, caused by SARS-CoV-2, affects neuronal cells, causing several symptoms such as memory loss, anosmia and brain inflammation. Curcuminoids (Me08 e Me23) and curcumin (CUR) are derived from Curcuma Longa extract (EXT). Many therapeutic actions have been linked to these compounds, including antiviral action. Given the severe implications of COVID-19, especially within the central nervous system, our study aims to shed light on the therapeutic potential of curcuminoids against SARS-CoV-2 infection, particularly in neuronal cells. Here, we investigated the effects of CUR, EXT, Me08 and Me23 in human neuroblastoma SH-SY5Y. We observed that Me23 significantly decreased the expression of plasma membrane-associated transmembrane protease serine 2 (TMPRSS2) and TMPRSS11D, consequently mitigating the elevated ROS levels induced by SARS-CoV-2. Furthermore, Me23 exhibited antioxidative properties by increasing NRF2 gene expression and restoring NQO1 activity following SARS-CoV-2 infection. Both Me08 and Me23 effectively reduced SARS-CoV-2 replication in SH-SY5Y cells overexpressing ACE2 (SH-ACE2). Additionally, all of these compounds demonstrated the ability to decrease proinflammatory cytokines such as IL-6, TNF-α, and IL-17, while Me08 specifically reduced INF-γ levels. Our findings suggest that curcuminoid Me23 could serve as a potential agent for mitigating the impact of COVID-19, particularly within the context of central nervous system involvement.

Sulforaphane upregulates the mRNA expression of NRF2 and NQO1 in non-dialysis patients with chronic kidney disease.

Sulforaphane (SFN), found in cruciferous vegetables, is a known activator of NRF2 (master regulator of cellular antioxidant responses). Patients with chronic kidney disease (CKD) present an imbalance in the redox state, presenting reduced expression of NRF2 and increased expression of NF-κB. Therefore, this study aimed to evaluate the effects of SFN on the mRNA expression of NRF2, NF-κB and markers of oxidative stress in patients with CKD. Here, we observed a significant increase in the mRNA expression of NRF2 (p = 0.02) and NQO1 (p = 0.04) in the group that received 400 µg/day of SFN for 1 month. Furthermore, we observed an improvement in the levels of phosphate (p = 0.02), glucose (p = 0.05) and triglycerides (p = 0.02) also in this group. On the other hand, plasma levels of LDL-c (p = 0.04) and total cholesterol (p = 0.03) increased in the placebo group during the study period. In conclusion, 400 µg/day of SFN for one month improves the antioxidant system and serum glucose and phosphate levels in non-dialysis CKD patients.

Mild hyperhomocysteinemia alters oxidative stress profile via Nrf2, inflammation and cholinesterases in cardiovascular system of aged male rats.

Homocysteine (Hcy) is an independent cardiovascular disease (CVD) risk factor, whose mechanisms are poorly understood. We aimed to explore mild hyperhomocysteinemia (HHcy) effects on oxidative status, inflammatory, and cholinesterase parameters in aged male Wistar rats (365 days old). Rats received subcutaneous Hcy (0.03 µmol/g body weight) twice daily for 30 days, followed by euthanasia, blood collection and heart dissection 12 h after the last injection. Results revealed increased dichlorofluorescein (DCF) levels in the heart and serum, alongside decreased antioxidant enzyme activities (superoxide dismutase, catalase, glutathione peroxidase), reduced glutathione (GSH) content, and diminished acetylcholinesterase (AChE) activity in the heart. Serum butyrylcholinesterase (BuChE) levels also decreased. Furthermore, nuclear factor erythroid 2-related factor 2 (Nrf2) protein content decreased in both cytosolic and nuclear fractions, while cytosolic nuclear factor kappa B (NFκB) p65 increased in the heart. Additionally, interleukins IL-1ß, IL-6 and IL-10 showed elevated expression levels in the heart. These findings could suggest a connection between aging and HHcy in CVD. Reduced Nrf2 protein content and impaired antioxidant defenses, combined with inflammatory factors and altered cholinesterases activity, may contribute to understanding the impact of Hcy on cardiovascular dynamics. This study sheds light on the complex interplay between HHcy, oxidative stress, inflammation, and cholinesterases in CVD, providing valuable insights for future research.

The Role of Oxidative Stress in Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Preclinical Studies.

Alcoholic Fatty Liver Disease (AFLD) is characterized by the accumulation of lipids in liver cells owing to the metabolism of ethanol. This process leads to a decrease in the NAD+/NADH ratio and the generation of reactive oxygen species. A systematic review and meta-analysis were conducted to investigate the role of oxidative stress in AFLD. A total of 201 eligible manuscripts were included, which revealed that animals with AFLD exhibited elevated expression of CYP2E1, decreased enzymatic activity of antioxidant enzymes, and reduced levels of the transcription factor Nrf2, which plays a pivotal role in the synthesis of antioxidant enzymes. Furthermore, animals with AFLD exhibited increased levels of lipid peroxidation markers and carbonylated proteins, collectively contributing to a weakened antioxidant defense and increased oxidative damage. The liver damage in AFLD was supported by significantly higher activity of alanine and aspartate aminotransferase enzymes. Moreover, animals with AFLD had increased levels of triacylglycerol in the serum and liver, likely due to reduced fatty acid metabolism caused by decreased PPAR-α expression, which is responsible for fatty acid oxidation, and increased expression of SREBP-1c, which is involved in fatty acid synthesis. With regard to inflammation, animals with AFLD exhibited elevated levels of pro-inflammatory cytokines, including TNF-a, IL-1ß, and IL-6. The heightened oxidative stress, along with inflammation, led to an upregulation of cell death markers, such as caspase-3, and an increased Bax/Bcl-2 ratio. Overall, the findings of the review and meta-analysis indicate that ethanol metabolism reduces important markers of antioxidant defense while increasing inflammatory and apoptotic markers, thereby contributing to the development of AFLD.

High-fat diet elicits sex-based differences in liver inflammatory cytokines and redox homeostasis.

Sex differences in metabolic dysfunction-associated steatotic liver disease (MASLD) have been reported. Oxidative stress and inflammation are involved in the progression of MASLD. Thus, we aimed to evaluate liver redox homeostasis and inflammation in male and female rats fed a high-fat diet (HFD). Male and female Wistar rats were divided into the following groups: standard chow diet (SCD) or HFD during 12 weeks. HFD groups of both sexes had higher hepatocyte injury, with no differences between the sexes. Portal space liver inflammation was higher in females-HFD compared to females-SCD, whereas no differences were observed in males. Lobular inflammation and overall liver inflammation were higher in HFD groups, regardless of sex. TNF-α, IL-6, and IL-1ß levels were higher in males-HFD compared to males-SCD, but no differences were observed in females. Catalase activity was higher in males compared to females, with no differences between the SCD and HFD groups of both sexes. Glutathione peroxidase activity was higher in females compared to males, with no differences between the SCD and HFD groups in both sexes. Lipid peroxidation was higher in female-SCD when compared to male-SCD, and in both male- and female-HFD compared to SCD groups. Furthermore, both cytoplasmic and nuclear NRF2 staining were lower in the HFD group compared to the SCD group in males. However, female-HFD exhibited reduced nuclear NRF2 staining compared to the female-SCD group. In conclusion, our study demonstrated that while both male and female rats developed metabolic dysfunction-associated steatohepatitis after 12 weeks of HFD, the alterations in inflammatory cytokines and redox balance were sexually dimorphic.

Post-treatment with maropitant reduces oxidative stress, endoplasmic reticulum stress and neuroinflammation on peripheral nerve injury in rats.

OBJECTIVE: To determine the effective dose and therapeutic potential of maropitant using through expression of mediators of oxidative stress, inflammatory and of the unfolded protein response (UPR) (bio) markers on spinal cord using a model of neuropathic pain induced through chronic constriction injury (CCI) in rats. STUDY DESIGN: Randomized, blinded, prospective experimental study. ANIMALS: 98 male Wistar rats. METHODS: Rats were anesthetized with sevoflurane and after CCI, they were randomly assigned to the following groups that received: vehicle, 3, 6, 15, 30 e 50 mg/kg/24q of maropitant. The effect on inflammatory mediators (IL10, TNFα), oxidative stress (GPx, CAT, SOD), microglial (IBA-1) and neuronal (NeuN, TACR1) markers was evaluated though immunohistochemistry and expression levels of markers of hypoxia (HIF1α, Nrf2), antioxidant enzymes (Catalse, Sod1 and GPx1), and endoplasmic reticulum stress mediators (GRP78, CHOP and PERK) through qRT-PCR. RESULTS: Intraperitoneal injection (IP) of maropitant inhibited nociception with ID50 values of 4,1 mg/kg (5,85-19,36) in a neuropathic pain model through CCI. A dose of 30 mg/kg/24q was significantly effective in reducing mechanical allodynia 1 to 4h after treatment with nociception inhibition (145,83%). A reduction in the expression of hypoxia factors (HIF1α, Nrf2) was observed, along with an increase in antioxidant activity (CAT, SOD and GPX). Additionally, there was a reduction in inflammatory markes (IL10, TNFα), microglial (IBA-1), and neuronal markers (NeuN, TACR1). CONCLUSION AND CLINICAL RELEVANCE: These findings demonstrate that the determined dose, administered daily for seven days, had an antinociceptive effect, as well as anti-inflammatory and antioxidant activity.

Interactions Between the Ubiquitin-Proteasome System, Nrf2, and the Cannabinoidome as Protective Strategies to Combat Neurodegeneration: Review on Experimental Evidence.

Neurodegenerative disorders are chronic brain diseases that affect humans worldwide. Although many different factors are thought to be involved in the pathogenesis of these disorders, alterations in several key elements such as the ubiquitin-proteasome system (UPS), the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, and the endocannabinoid system (ECS or endocannabinoidome) have been implicated in their etiology. Impairment of these elements has been linked to the origin and progression of neurodegenerative disorders, while their potentiation is thought to promote neuronal survival and overall neuroprotection, as proved with several experimental models. These key neuroprotective pathways can interact and indirectly activate each other. In this review, we summarize the neuroprotective potential of the UPS, ECS, and Nrf2 signaling, both separately and combined, pinpointing their role as a potential therapeutic approach against several hallmarks of neurodegeneration.

Nrf2 activation by hydroxytyrosol and dimethyl fumarate ameliorates skin tissue repair in high-fat diet-fed mice by promoting M2 macrophage polarization and normalizing inflammatory response and oxidative damage.

Hydroxytyrosol (HT) or dimethyl fumarate (DMF), activators of nuclear factor erythroid 2-related factor 2 (Nrf2), may reduce obesity in high-fat diet (HFD)-fed animals; nevertheless, the role of these activators on skin tissue repair of HFD-fed animals was not reported. This study investigated whether HT or DMF could improve skin wound healing of HFD-fed obese animals. Mice were fed with an HFD, treated with HT or DMF, and full-thickness skin wounds were created. Macrophages isolated from control and obese animals were treated in vitro with HT. DMF, but not HT, reduced the body weight of HFD-fed mice. Collagen deposition and wound closure were improved by HT or DMF in HFD-fed animals. HT or DMF increased anti-inflammatory macrophage phenotype and protein Nrf2 levels in wounds of HFD-fed mice. Lipid peroxidation and protein tumor necrosis factor-α levels were reduced by HT or DMF in wounds of HFD-fed animals. In in vitro, HT stimulated Nrf2 activation in mouse macrophages isolated from obese animals. In conclusion, HT or DMF improves skin wound healing of HFD-fed mice by reducing oxidative damage and inflammatory response. HT or DMF may be used as a therapeutic strategy to improve the skin healing process in individuals with obesity.

Can curcumin supplementation break the vicious cycle of inflammation, oxidative stress, and uremia in patients undergoing peritoneal dialysis?

BACKGROUND & AIMS: Turmeric (a source of curcumin) is an excellent food to modulate oxidative stress, inflammation, and gut dysbiosis in patients with chronic kidney disease (CKD). However, no studies report the benefits of curcumin in patients undergoing peritoneal dialysis (PD). This study aims to evaluate the effects of curcuminoid supplementation on oxidative stress, inflammatory markers, and uremic toxins originating from gut microbiota in patients with CKD undergoing PD. METHODS: This longitudinal, randomized, single-blind, placebo-controlled trial evaluated 48 patients who were randomized into two groups: Curcumin (three capsules of 500 mg of Curcuma longa extract, with 98.42 % total curcuminoids) or placebo (three capsules of 500 mg of starch) for twelve weeks. In the peripheral blood mononuclear cells (PBMCs), the transcriptional expression levels of Nrf2, HOX-1 and NF-κB were evaluated by quantitative real-time PCR. Oxidative stress was evaluated by malondialdehyde (MDA) and total Thiol (T-SH). TNF-α and IL-6 plasma levels were measured by ELISA. P-cresyl sulphate plasma level, a uremic toxin, was evaluated by high-performance liquid chromatography (HPLC) with fluorescent detection. RESULTS: Twenty-four patients finished the study: 10 in the curcumin group (57.5 ± 11.6 years) and 14 in the placebo group (56.5 ± 10.0 years). The plasma levels of MDA were reduced after 12 weeks in the curcumin group (p = 0.01), while the placebo group remained unchanged. However, regarding the difference between the groups at the endpoint, no change was observed in MDA. Still, there was a trend to reduce the p-CS plasma levels in the curcumin group compared to the placebo group (p = 0.07). Likewise, the concentrations of protein thiols, mRNA expression of Nrf2, HOX-1, NF-κB, and cytokines plasma levels did not show significant changes. CONCLUSION: Curcuminoid supplementation for twelve weeks attenuates lipid peroxidation and might reduce uremic toxin in patients with CKD undergoing PD. This study was registered on Clinicaltrials.gov as NCT04413266.

Sulforaphane Supplementation Did Not Modulate NRF2 and NF-kB mRNA Expressions in Hemodialysis Patients.

BACKGROUND: Patients with chronic kidney disease (CKD) have reduced expression of erythroid nuclear factor-related factor 2 (NRF2) and increased nuclear factor κB (NF-κB). "Food as medicine" has been proposed as an adjuvant therapeutic alternative in modulating these factors. No studies have investigated the effects of sulforaphane (SFN) in cruciferous vegetables on the expression of these genes in patients with CKD. OBJECTIVE: The study aimed to evaluate the effects of SFN on the expression of NRF2 and NF-κB in patients on hemodialysis (HD). DESIGN AND METHODS: A randomized, double-blind, crossover study was performed on 30 patients on regular HD. Fourteen patients were randomly allocated to the intervention group (1 sachet/day of 2.5 g containing 1% SFN extract with 0.5% myrosinase) and 16 patients to the placebo group (1 sachet/day of 2.5 g containing corn starch colored with chlorophyll) for 2 months. After a washout period of 2 months, the groups were switched. NRF2 and NF-κB mRNA expression was evaluated by real-time quantitative polymerase chain reaction, and tumor necrosis factor alpha and interleukin-6 levels were quantified by enzyme-linked immunosorbent assay. Malondialdehyde was evaluated as a marker of lipid peroxidation. RESULTS: Twenty-five patients (17 women, 55 [interquartile range = 19] years and 55 [interquartile range = 74] months on HD) completed the study. There was no significant difference concerning the expression of mRNA NRF2 (P = .915) and mRNA NF-κB (P = .806) after supplementation with SFN. There was no difference in pro-inflammatory and oxidative stress biomarkers. CONCLUSION: 150 µmol of SFN for 2 months had no antioxidant and anti-inflammatory effect in patients with CKD undergoing HD.

Selenium bioavailability modulates the sensitivity of thyroid cells to iodide excess.

INTRODUCTION: Iodide is an essential micronutrient for the synthesis of thyroid hormones and its imbalance is involved in the origin of different thyroid pathological processes. Selenium (Se) is another essential trace element that contributes to thyroid preservation through the control of the redox homeostasis. Different studies have demonstrated that sodium-iodide-symporter (NIS) is downregulated in the presence of iodide excess and Se supplementation reverses this effect. We also demonstrated that NOX4-derived ROS are involved in NIS repression induced by iodide excess. The aim of this study was to investigate how Se bioavailability is decisive in the sensitivity to iodide excess on a differentiated rat thyroid cell line (FRTL-5). RESULTS: We demonstrated that siRNA-mediated silencing of Nox4 suppressed AKT phosphorylation induced by iodide excess. Iodide increases TGF-ß1 mRNA expression, AKT phosphorylation, ROS levels and decreases GPX1 and TXRND1 mRNAs expression while Se reversed these effects. Furthermore, iodide induced Nrf2 transcriptional activity only in Se-supplemented cultures, suggesting that Se positively influences Nrf2 activation and selenoenzyme response in FRTL-5. Se, also inhibited NF-κB phosphorylation induced by iodide excess. In addition, we found that iodide excess decreased total phosphatase activity and PTP1B and PTEN mRNA expression. Se supply restored only PTEN mRNA expression. Finally, we studied the 2-α-iodohexadecanal (2-IHD) effects since it has been proposed as intermediary of iodide action on thyroid autoregulation. 2-IHD stimulated PI3K/AKT activity and reduced NIS expression by a ROS-independent mechanism. Also, we found that 2-IHD increased TGF-ß1 mRNA and TGF-ß inhibitor (SB431542) reverses the 2-IHD inhibitory effect on NIS mRNA expression, suggesting that TGF-ß1 signaling pathway could be involved. Although Se reduced 2-IHD-induced TGFB1 levels, it could not reverse its inhibitory effect on NIS expression. CONCLUSION: Our study suggests that Se bioavailability may improve the expression of antioxidant genes through the activation of Nrf2, interfere in PI3K/AKT signaling and NIS expression by redox modulation.