Existing and potential therapeutic uses for N-acetylcysteine: the need for conversion to intracellular glutathione for antioxidant benefits. Pharmacol Ther. 2014;141:150-159. [PMID: 24080471 DOI: 10.1016/j.pharmthera.2013.09.006]

Durable cellulose paper by grafting thiol groups and controlling silver deposition for ultrahigh electromagnetic interference shielding

Electromagnetic interference (EMI) shielding paper with durability and high effectiveness is of significant importance to long-term service for preventing EMI pollution. Herein, we report a practical method for preparing cellulose paper/Ag composite with outstanding durable and ultrahigh EMI shielding performance by electroless silver plating. The silver deposition process, the surface morphology, the silver content and conductivity of the composite can be controlled by varying the amount of N-acetyl-L-cysteine (NAC) grafted onto the cellulose fibers and ammonia amount for silver-ammonia complex formation. Moreover, the grafted NAC with thiol groups on cellulose can enhance the adhesion between silver and cellulose paper, meanwhile, NAC as the reducing agent can result in a more complete flower-shaped silver structure and reducing the reflection of electromagnetic waves in silver layer. The composite exhibited excellent conductivity, EMI shielding effectiveness (SE) up to 106 dB and outstanding durability. After 10,000 bending times and 60 abrasion cycles respectively, the electrical resistance of the composite only increased from 0.030 Ω/sq. to 0.041 Ω/sq. and 0.050 Ω/sq., and the EMI SE decreased to 102 dB and 105 dB.

Endogenous and Exogenous Antioxidants as Agents Preventing the Negative Effects of Contrast Media (Contrast-Induced Nephropathy)

The use of conventional contrast media for diagnostic purposes (in particular, Gd-containing and iodinated agents) causes a large number of complications, the most common of which is contrast-induced nephropathy. It has been shown that after exposure to contrast agents, oxidative stress often occurs in patients, especially in people suffering from various diseases. Antioxidants in the human body can diminish the pathological consequences of the use of contrast media by suppressing oxidative stress. This review considers the research studies on the role of antioxidants in preventing the negative consequences of the use of contrast agents in diagnostics (mainly contrast-induced nephropathy) and the clinical trials of different antioxidant drugs against contrast-induced nephropathy. Composite antioxidant/contrast systems as theranostic agents are also considered.

Free Radical and Viral Infection: A Review from the Perspective of Ferroptosis

Free radicals, including reactive oxygen species (ROS) and reactive nitrogen species (RNS), play critical roles in various physiological activities such as cell differentiation, apoptosis, and vascular tension when existing in cells at low levels. However, excessive amounts of free radicals are harmful, causing DNA damage, lipid peroxidation, protein degeneration, and abnormal cell death. Certain viral infections induce cells to produce excessive free radicals, which in multiple ways help the virus to replicate, mature, and exit. Iron is a necessary element for many intracellular enzymes, involved in both cellular activities and viral replication. Ferroptosis, a programmed cell death mode distinct from apoptosis, necrosis, and pyroptosis, is characterized by lipid peroxide accumulation and damage to the antioxidant system, affecting many cellular processes. Viral infection commonly manifests as decreased glutathione (GSH) content and down-regulated glutathione peroxidase 4 (GPX4) activity, similar to ferroptosis. Recent studies have suggested a possible relationship among free radicals, viral infections and ferroptosis. This review aims to elucidate the molecular mechanism linking free radicals and ferroptosis during viral infections and provide a new theoretical basis for studying viral pathogenesis and control.

ROS inhibition increases KDM6A-mediated NOX2 transcription and promotes macrophages oxidative stress and M1 polarization

Reactive oxygen species (ROS) play an essential role in macrophage polarization. However, the adverse effects of ROS reduction by influencing epigenetics are often ignored. In this study, lipopolysaccharide (LPS) was used to stimulate macrophages to increase the ROS in cells, and N-acetylcysteine (NAC) was used to reduce ROS. Inflammatory factors such as interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were used to evaluate the M1 polarization level of macrophages. Chip was used to detect the tri-methylation at lysine 27 of histone H3 (H3K27me3) level at the promoter site. It was found that the decrease of ROS in macrophages would also cause the increase of the H3K27me3 demethylase KDM6A and lead to the reduction of H3K27me3 in the NOX2 promoter, which would increase the transcription level of NOX2 and the production of ROS and ultimately promote the production of inflammatory factors. Knockout of KDM6A can reduce the transcription of NOX2 and the production of ROS of macrophages, thus preventing the M1 polarization of macrophages. The elimination of ROS in macrophages will affect macrophages by increasing KDM6A and making them produce more ROS, thus inducing oxidative stress. In comparison, direct inhibition of KDM6A can reduce ROS production and inhibit macrophage M1 polarization more effectively.

Copper in cancer: from limiting nutrient to therapeutic target

As an essential nutrient, copper's redox properties are both beneficial and toxic to cells. Therefore, leveraging the characteristics of copper-dependent diseases or using copper toxicity to treat copper-sensitive diseases may offer new strategies for specific disease treatments. In particular, copper concentration is typically higher in cancer cells, making copper a critical limiting nutrient for cancer cell growth and proliferation. Hence, intervening in copper metabolism specific to cancer cells may become a potential tumor treatment strategy, directly impacting tumor growth and metastasis. In this review, we discuss the metabolism of copper in the body and summarize research progress on the role of copper in promoting tumor cell growth or inducing programmed cell death in tumor cells. Additionally, we elucidate the role of copper-related drugs in cancer treatment, intending to provide new perspectives for cancer treatment.

The Role of Glutathione in Selected Viral Diseases

During inflammatory processes, immunocompetent cells are exposed to substantial amounts of free radicals and toxic compounds. Glutathione is a cysteine-containing tripeptide that is an important and ubiquitous antioxidant molecule produced in human organs. The intracellular content of GSH regulates the detoxifying capacity of cells, as well as the inflammatory and immune response. GSH is particularly important in the liver, where it serves as the major non-protein thiol involved in cellular antioxidant defense. There are numerous causes of hepatitis. The inflammation of the liver can be caused by a variety of infectious viruses. The relationship between oxidative stress and the hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis E virus (HEV) infection is not fully known. The aim of this study was to examine the relationship between hepatotropic viruses and glutathione status, including reduced glutathione (GSH) and oxidized glutathione (GSSG), as well as antioxidant enzymes, e.g., glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) in liver diseases.

N-Acetylcysteine Treatment May Compensate Motor Impairments through Dopaminergic Transmission Modulation in a Striatal 6-Hydroxydopamine Parkinson's Disease Rat Model

Preventing degeneration and the loss of dopaminergic neurons (DAn) in the brain while mitigating motor symptoms remains a challenge in Parkinson's Disease (PD) treatment development. In light of this, developing or repositioning potential disease-modifying approaches is imperative to achieve meaningful translational gains in PD research. Under this concept, N-acetylcysteine (NAC) has revealed promising perspectives in preserving the dopaminergic system capability and modulating PD mechanisms. Although NAC has been shown to act as an antioxidant and (neuro)protector of the brain, it has yet to be acknowledged how this repurposed drug can improve motor symptomatology and provide disease-modifying properties in PD. Therefore, in the present work, we assessed the impact of NAC on motor and histological deficits in a striatal 6-hydroxydopamine (6-OHDA) rat model of PD. The results revealed that NAC enhanced DAn viability, as we found that it could restore dopamine transporter (DAT) levels compared to the untreated 6-OHDA group. Such findings were positively correlated with a significant amelioration in the motor outcomes of the 6-OHDA-treated animals, demonstrating that NAC may, somehow, be a modulator of PD degenerative mechanisms. Overall, we postulated a proof-of-concept milestone concerning the therapeutic application of NAC. Nevertheless, it is extremely important to understand the complexity of this drug and how its therapeutical properties interact with the cellular and molecular PD mechanisms.

Schistosomicidal, hepatoprotective and antioxidant activities of the N-acetyl-L-cysteine and/or praziquantel in experimental acute mansonic schistosomiasis

Schistosomiasis is a tropical parasitic disease, in which the major clinical manifestation includes hepatosplenomegaly, portal hypertension, and organs fibrosis. Clinically, treatment of schistosomiasis involves the use of praziquantel (PZQ) and supportive care, which does not improve the patient's outcome as liver injuries persist. Here, we report for the first time the effect of N-acetyl-L-cysteine (NAC) and/or praziquantel (PQZ) on S. mansoni, hepatic granuloma, serum markers for liver function and oxidative damage in acute schistosomiasis. Infected mice were divided into control, NAC, PZQ and NAC+PZQ groups and uninfected into control and NAC groups. After infection, NAC (200 mg/kg/day) was administrated until the 60th day and PZQ (100 mg/kg/day) from the 45th to the 49th day, both orally. On day 61, the mice were euthanized for serum markers for liver function. Worms were recovered, fragments of intestine employed to ascertain the oviposition pattern, and the liver was used for histopathological analysis, histomorphometry, egg and granuloma counting and oxidative stress marker assays. NAC reduced the burden of worms and eggs and increased the dead eggs in intestinal tissue. NAC+PZQ brought about reduction in granulomatous infiltration and NAC and/or PZQ reduced levels of ALT, AST, and alkaline phosphatase and increased albumin. NAC, PZQ or NAC+PZQ reduced levels of the superoxide anion, lipid peroxidation and protein carbonyl and increased sulfhydryl groups. The reduction in parasitological parameters, granulomatous inflammation and oxy-redox imbalance suggests NAC acts as a adjuvant in treatment of acute experimental schistosomiasis.

Effect of N-Acetylcysteine on Sleep: Impacts of Sex and Time of Day

Non-rapid eye movement sleep (NREMS) is accompanied by a decrease in cerebral metabolism, which reduces the consumption of glucose as a fuel source and decreases the overall accumulation of oxidative stress in neural and peripheral tissues. Enabling this metabolic shift towards a reductive redox environment may be a central function of sleep. Therefore, biochemical manipulations that potentiate cellular antioxidant pathways may facilitate this function of sleep. N-acetylcysteine increases cellular antioxidant capacity by serving as a precursor to glutathione. In mice, we observed that intraperitoneal administration of N-acetylcysteine at a time of day when sleep drive is naturally high accelerated the onset of sleep and reduced NREMS delta power. Additionally, N-acetylcysteine administration suppressed slow and beta electroencephalographic (EEG) activities during quiet wake, further demonstrating the fatigue-inducing properties of antioxidants and the impact of redox balance on cortical circuit properties related to sleep drive. These results implicate redox reactions in the homeostatic dynamics of cortical network events across sleep/wake cycles, illustrating the value of timing antioxidant administration relative to sleep/wake cycles. A systematic review of the relevant literature, summarized herein, indicates that this "chronotherapeutic hypothesis" is unaddressed within the clinical literature on antioxidant therapy for brain disorders such as schizophrenia. We, therefore, advocate for studies that systematically address the relationship between the time of day at which an antioxidant therapy is administered relative to sleep/wake cycles and the therapeutic benefit of that antioxidant treatment in brain disorders.

Acute alcohol-associated hepatitis: Latest findings in non-invasive biomarkers and treatment

Acute alcohol-associated hepatitis (AH) is a syndrome that occurs in heavy and long-term drinkers and results in severe jaundice and liver failure. The mortality rate in severe cases is 20%-50% at 28 days, and in cases that do not improve despite appropriately timed corticosteroid therapy, the mortality rate reaches 70% at 6 months. The only curative treatment is early liver transplantation, but less than 2% of patients with severe AH are eligible. In order to improve the prognosis, diagnostic tools are needed to detect appropriate cases at risk of severe conditions, and new therapies need to be developed that can replace corticosteroids. Recent research has revealed that the pathogenesis of AH involves a complex of factors, including changes in the gut microbiota, inflammatory and cytokine signalling, oxidative stress and mitochondrial dysfunction, and abnormalities in the hepatic regenerative capacity. Non-invasive diagnostic tools focusing on these specific pathologies have been reported in recent years. In addition, several novel agents targeting specific pathways are currently being developed and tested in clinical trials. This review will provide an overview of alcohol-associated hepatitis and focus on the latest diagnostic tools, particularly non-invasive biomarkers, and novel therapies.

Response to Intravenous N-Acetylcysteine Supplementation in Critically Ill Patients with COVID-19

Administering N-acetylcysteine (NAC) could counteract the effect of free radicals, improving the clinical evolution of patients admitted to the Intensive Care Unit (ICU). This study aimed to investigate the clinical and biochemical effects of administering NAC to critically ill patients with COVID-19. A randomized controlled clinical trial was conducted on ICU patients (n = 140) with COVID-19 and divided into two groups: patients treated with NAC (NAC-treated group) and patients without NAC treatment (control group). NAC was administered as a continuous infusion with a loading dose and a maintenance dose during the study period (from admission until the third day of ICU stay). NAC-treated patients showed higher PaO₂/FiO₂ (p ≤ 0.014) after 3 days in ICU than their control group counterparts. Moreover, C-reactive protein (p ≤ 0.001), D-dimer (p ≤ 0.042), and lactate dehydrogenase (p ≤ 0.001) levels decreased on the third day in NAC-treated patients. Glutathione concentrations decreased in both NAC-treated (p ≤ 0.004) and control (p ≤ 0.047) groups after 3 days in ICU; whereas glutathione peroxidase did not change during the ICU stay. The administration of NAC manages to improve the clinical and analytical response of seriously ill patients with COVID-19 compared to the control group. NAC is able to stop the decrease in glutathione concentrations.

Influence of dose and exposition time in the effectiveness of N-Acetyl-l-cysteine treatment in A549 human epithelial cells

N-Acetyl-l-cysteine (NAC) acts as a precursor of the tripeptide glutathione (GSH), one of the principal cell mechanisms for reactive oxygen species (ROS) detoxification. Chronic obstructive pulmonary disease (COPD) is associated with enhanced inflammatory response and oxidative stress and NAC has been used to suppress various pathogenic processes in this disease. Studies show that the effects of NAC are dose-dependent, and it appears that the efficient doses in vitro are usually higher than the achieved in vivo plasma concentrations. However, to date, the inconsistencies between the in vitro NAC antioxidant and anti-inflammatory in vitro effects, by reproducing the in vivo NAC plasma concentrations as well as high NAC concentrations. To do so, A549 were transfected with polyinosinic-polycytidylic acid (Poly (I:C)) and treated with NAC at different treatment periods. Oxidative stress, release of proinflammatory mediators and NFkB activation were analyzed. Results suggest that NAC at low doses in chronic administration has sustained antioxidant and anti-inflammatory effects, while acute treatment with high dose NAC exerts a strong antioxidant and anti-inflammatory response.

Ferroptotic mechanisms and therapeutic targeting of iron metabolism and lipid peroxidation in the kidney

Ferroptosis is a mechanism of regulated necrotic cell death characterized by iron-dependent, lipid peroxidation-driven membrane destruction that can be inhibited by glutathione peroxidase 4. Morphologically, it is characterized by cellular, organelle and cytoplasmic swelling and the loss of plasma membrane integrity, with the release of intracellular components. Ferroptosis is triggered in cells with dysregulated iron and thiol redox metabolism, whereby the initial robust but selective accumulation of hydroperoxy polyunsaturated fatty acid-containing phospholipids is further propagated through enzymatic and non-enzymatic secondary mechanisms, leading to formation of oxidatively truncated electrophilic species and their adducts with proteins. Thus, ferroptosis is dependent on the convergence of iron, thiol and lipid metabolic pathways. The kidney is particularly susceptible to redox imbalance. A growing body of evidence has linked ferroptosis to acute kidney injury in the context of diverse stimuli, such as ischaemia-reperfusion, sepsis or toxins, and to chronic kidney disease, suggesting that ferroptosis may represent a novel therapeutic target for kidney disease. However, further work is needed to address gaps in our understanding of the triggers, execution and spreading mechanisms of ferroptosis.

Reproductive toxicity of enrofloxacin in Caenorhabditis elegans involves oxidative stress-induced cell apoptosis

Fluoroquinolone antibiotics (FQs) that persist and bioaccumulate in the environment have aroused people's great concern. Here, we studied the adverse effects of FQs in soil animals of Caenorhabditis elegans via food-chronically exposure. The result shows C. elegans exposed to FQs exhibited reproductive toxicity with small-brood size and low-egg hatchability. To study the underlying mechanism, we conduct a deep investigation of enrofloxacin (ENR), one of the most frequently detected FQs, on nematodes which is one of commonly used animal indicator of soil sustainability. The concentration-effect curves simulated by the Hill model showed that the half effect concentrations (EC₅₀) of ENR were (494.3 ± 272.9) µmol/kg and (107.4 ± 30.9) µmol/kg for the brood size and the hatchability, respectively. Differential gene expression between the control and the ENR-exposure group enriched with the oxidative stress and cell apoptosis pathways. The results together with the enzyme activity in oxidative stress and the cell corpses suggested that ENR-induced reproductive toxicity was related to germ cell apoptosis under oxidative stress. The risk quotients of some soil and livestock samples were calculated based on the threshold value of EC₁₀ for the egg hatchability (2.65 µmol/kg). The results indicated that there was possible reproductive toxicity on the nematodes in certain agricultural soils for the FQs. This study suggested that chronic exposure to FQs at certain levels in environment would induce reproductive toxicity to the nematodes and might reduce the soil sustainability, alarming the environment risks of antibiotics abuse.

N-acetylcysteine modulates redox imbalance and inflammation in macrophages and mice exposed to formaldehyde

This study aimed to evaluate the protective role of N-acetylcysteine (NAC) in cells and mice exposed to formaldehyde. For the in vitro study, J774A.1 macrophages cells were incubated for 8, 16 and 24 h with formaldehyde or NAC to assess cell viability and reactive oxygen species (ROS). In the in vivo study, C57BL/6 mice (n = 48) were divided into 6 groups: control (CG), vehicle (VG) that received saline by orogastric gavage, a group exposed to formaldehyde 1% (FG) and formaldehyde exposed groups that received NAC at doses of 100, 150 and 200 mg/Kg (FN100, FN150 and FN200) for a period of 5 days. In vitro, formaldehyde promoted a decrease in cell viability and increased ROS, while NAC reduced formaldehyde-induced ROS production. Animals exposed to formaldehyde presented higher leukocyte counts in the blood and in the bronchoalveolar lavage fluid, and promoted secretion of inflammatory markers IL-6, IL-15, and IL-10. The exposure to formaldehyde also promoted redox imbalance and oxidative damage characterized by increased activities of superoxide dismutase, catalase, decreased GSH/GSSG ratio, as well as it increased levels of protein carbonyls and lipid peroxidation. NAC administration after formaldehyde exposure attenuated oxidative stress markers, secretion of inflammatory mediators and lung inflammation. In conclusion, both in in vitro and in vivo models, NAC administration exerted protective effects, which modulated the inflammatory response and redox imbalance, thus preventing the development airway injury induced by formaldehyde exposure.

Oxidative Stress in Diabetic Peripheral Neuropathy: Pathway and Mechanism-Based Treatment

Diabetic peripheral neuropathy (DPN) is a major complication of diabetes mellitus with a high incidence. Oxidative stress, which is a crucial pathophysiological pathway of DPN, has attracted much attention. The distortion in the redox balance due to the overproduction of reactive oxygen species (ROS) and the deregulation of antioxidant defense systems promotes oxidative damage in DPN. Therefore, we have focused on the role of oxidative stress in the pathogenesis of DPN and elucidated its interaction with other physiological pathways, such as the glycolytic pathway, polyol pathway, advanced glycosylation end products, protein kinase C pathway, inflammation, and non-coding RNAs. These interactions provide novel therapeutic options targeting oxidative stress for DPN. Furthermore, our review addresses the latest therapeutic strategies targeting oxidative stress for the rehabilitation of DPN. Antioxidant supplements and exercise have been proposed as fundamental therapeutic strategies for diabetic patients through ROS-mediated mechanisms. In addition, several novel drug delivery systems can improve the bioavailability of antioxidants and the efficacy of DPN.

Nuciferine Effectively Protects Mice against Acetaminophen-Induced Liver Injury

Acetaminophen (APAP) overdose still poses a major clinical challenge and is a leading cause of acute liver injury (ALI). N-acetylcysteine (NAC) is the only approved antidote to treat APAP toxicity while NAC therapy can trigger side effects including severe vomiting and even shock. Thus, new insights in developing novel therapeutic drugs may pave the way for better treatment of APAP poisoning. Previous research has reported that nuciferine (Nuci) possesses anti-inflammatory and antioxidant properties. Therefore, the objective of this study was proposed to investigate the hepatoprotective effects of Nuci and explore its underlying mechanisms. Mice were intraperitoneally (i.p.) administered with APAP (300 mg/kg) and subsequently injected with Nuci (25, 50, and 100 mg/kg, i.p.) at 30 min after APAP overdose. Then, all mice were sacrificed at 12 h after APAP challenge for further analysis. Nuci-treated mice did not show any side effects and our results revealed that treating Nuci significantly attenuated APAP-induced ALI, as confirmed by histopathological examinations, biochemical analysis, and diminished hepatic oxidative stress and inflammation. The in silico prediction and mRNA-sequencing analysis were performed to explore the underlying mechanisms of Nuci. GO and KEGG enrichment of the predicted target proteins of Nuci includes reactive oxygen species, drug metabolism of cytochrome P450 (CYP450) enzymes, and autophagy. Furthermore, the mRNA-sequencing analyses indicated that Nuci can regulate glutathione metabolic processes and anti-inflammatory responses. Consistently, we found that Nuci increased the hepatic glutathione restoration but decreased APAP protein adducts in damaged livers. Western blot analysis further confirmed that Nuci effectively promoted hepatic autophagy in APAP-treated mice. However, Nuci could not affect the expression levels of the main CYP450 enzymes (CYP1A2, CYP2E1, and CYP3A11). These results demonstrated that Nuci may be a potential therapeutic drug for APAP-induced ALI via amelioration of the inflammatory response and oxidative stress, regulation of APAP metabolism, and activation of autophagy.

Evaluation of cigarette smoke-induced oxidative stress and inflammation in BEAS-2B cells based on a lung microfluidic chip

Oxidative stress and inflammation induced by cigarette smoking are associated with the pathology process of various chronic respiratory diseases, including asthma, emphysema, chronic obstructive pulmonary disease and cancer. Compared with conventional cell culture techniques, microfluidic chips can provide a continuous nutrient supply, mimic the in vivo physiological microenvironment of the cells, and conduct an integrated and flexible analysis of cell status and functions. Here, we designed and fabricated a bionic-lung chip, which was applied to perform cigarette smoke exposure of BEAS-2B cells cultured at the gas-liquid interface. The oxidative stress and inflammation in the cells exposed to cigarette smoke were investigated on chip. The results showed that cellular damage, oxidative stress and inflammatory response induced by cigarette smoke in the chip were dependent on smoke concentration and time after smoke exposure. N-Acetylcysteine (NAC) significantly inhibited these effects of cigarette smoke exposure on the cells at the gas-liquid interface within the chip.

Simultaneous Elimination of Reactive Oxygen Species and Activation of Nrf2 by Ultrasmall Nanoparticles to Relieve Acute Kidney Injury

Excess reactive oxygen species (ROS) can induce serious acute kidney injury (AKI) to result in numerous deaths annually in clinical practice. Elimination of excess ROS by advanced nanotechnology is a very promising AKI therapy. In this Article, we report that PVP-stabilized and quercetin-functionalized ultrasmall Cu_2-xSe nanoparticles (abbreviated as CSPQ NPs) can efficiently scavenge ROS and increase the expression of intracellular antioxidative enzymes by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) protein, which drastically alleviates the cellular oxidative stress. Our ultrasmall nanoparticles exhibit excellent biocompatibility. They can be rapidly accumulated into the injured kidney to simultaneously eliminate ROS and activate Nrf2 to improve the renal function. This work demonstrates the great potential of simultaneous elimination of ROS and activation of intracellular Nrf2 in treatment of AKI. It also highlights the potential of CSPQ NPs in protection and prevention of AKI.

Human hair proteins as natural reactive oxygen species scavengers for in vitro applications

Human hair proteins are recognized for their intrinsically high cysteine content. They can be solubilized while preserving their highly reductive thiol groups for free radical scavenging applications. The presence of aromatic and nucleophilic amino acids such as methionine, serine, phenylalanine, and threonine further contribute to the antioxidative potential of this material. Herein, utilizing the DPPH (2,2-diphenyl-1-picrylhydrazyl) and acellular 2',7'-dichlorodihydrofluorescein diacetate (H₂ DCFDA) assays, keratins are demonstrated to possess the highest radical scavenging activity among the studied hair proteins. Consequently, protection against hydrogen peroxide-induced oxidative stress in human dermal fibroblasts (HDFs) cultured in human hair keratin supplemented media is demonstrated. Quenching of reactive oxygen species in the HDF is observed using the CellROX Green dye and the expression levels of antioxidant (HMOX1, SOD2, GPX1) and tumor suppressor (TP53) genes is analyzed using qPCR. Collectively, this study presents further evidence and demonstrates the in vitro application potential of hair proteins, especially keratins, as an antioxidizing supplement.

Nanodrugs alleviate acute kidney injury: Manipulate RONS at kidney

Currently, there are no clinical drugs available to treat acute kidney injury (AKI). Given the high prevalence and high mortality rate of AKI, the development of drugs to effectively treat AKI is a huge unmet medical need and a research hotspot. Although existing evidence fully demonstrates that reactive oxygen and nitrogen species (RONS) burst at the AKI site is a major contributor to AKI progression, the heterogeneity, complexity, and unique physiological structure of the kidney make most antioxidant and anti-inflammatory small molecule drugs ineffective because of the lack of kidney targeting and side effects. Recently, nanodrugs with intrinsic kidney targeting through the control of size, shape, and surface properties have opened exciting prospects for the treatment of AKI. Many antioxidant nanodrugs have emerged to address the limitations of current AKI treatments. In this review, we systematically summarized for the first time about the emerging nanodrugs that exploit the pathological and physiological features of the kidney to overcome the limitations of traditional small-molecule drugs to achieve high AKI efficacy. First, we analyzed the pathological structural characteristics of AKI and the main pathological mechanism of AKI: hypoxia, harmful substance accumulation-induced RONS burst at the renal site despite the multifactorial initiation and heterogeneity of AKI. Subsequently, we introduced the strategies used to improve renal targeting and reviewed advances of nanodrugs for AKI: nano-RONS-sacrificial agents, antioxidant nanozymes, and nanocarriers for antioxidants and anti-inflammatory drugs. These nanodrugs have demonstrated excellent therapeutic effects, such as greatly reducing oxidative stress damage, restoring renal function, and low side effects. Finally, we discussed the challenges and future directions for translating nanodrugs into clinical AKI treatment.

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AKI is a common clinical acute syndrome with high morbidity and mortality but without effective clinical drug available.

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Hypoxia and accumulation of toxic substances are key pathological features of various heterogeneous AKI.

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Excessive RONS is the core of the pathological mechanism of AKI.

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The development of nanodrugs is expected to achieve successful treatment in AKI.

Development of Dipeptide N–acetyl–L–cysteine Loaded Nanostructured Carriers Based on Inorganic Layered Hydroxides

N–acetyl–L–cysteine (NAC), a derivative of the L–cysteine amino acid, presents antioxidant and mucolytic properties of pharmaceutical interest. This work reports the preparation of organic-inorganic nanophases aiming for the development of drug delivery systems based on NAC intercalation into layered double hydroxides (LDH) of zinc–aluminum (Zn2Al–NAC) and magnesium–aluminum (Mg2Al–NAC) compositions. A detailed characterization of the synthesized hybrid materials was performed, including X-ray diffraction (XRD) and pair distribution function (PDF) analysis, infrared and Raman spectroscopies, solid-state 13carbon and 27aluminum nuclear magnetic resonance (NMR), simultaneous thermogravimetric and differential scanning calorimetry coupled to mass spectrometry (TG/DSC–MS), scanning electron microscopy (SEM), and elemental chemical analysis to assess both chemical composition and structure of the samples. The experimental conditions allowed to isolate Zn2Al–NAC nanomaterial with good crystallinity and a loading capacity of 27.3 (m/m)%. On the other hand, NAC intercalation was not successful into Mg2Al–LDH, being oxidized instead. In vitro drug delivery kinetic studies were performed using cylindrical tablets of Zn2Al–NAC in a simulated physiological solution (extracellular matrix) to investigate the release profile. After 96 h, the tablet was analyzed by micro-Raman spectroscopy. NAC was replaced by anions such as hydrogen phosphate by a slow diffusion-controlled ion exchange process. Zn2Al–NAC fulfil basic requirements to be employed as a drug delivery system with a defined microscopic structure, appreciable loading capacity, and allowing a controlled release of NAC.

Neuroinflammation and Oxidative Stress in the Pathogenesis of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder (NDD) characterized by impairments in social communication, repetitive behaviors, restricted interests, and hyperesthesia/hypesthesia caused by genetic and/or environmental factors. In recent years, inflammation and oxidative stress have been implicated in the pathogenesis of ASD. In this review, we discuss the inflammation and oxidative stress in the pathophysiology of ASD, particularly focusing on maternal immune activation (MIA). MIA is a one of the common environmental risk factors for the onset of ASD during pregnancy. It induces an immune reaction in the pregnant mother’s body, resulting in further inflammation and oxidative stress in the placenta and fetal brain. These negative factors cause neurodevelopmental impairments in the developing fetal brain and subsequently cause behavioral symptoms in the offspring. In addition, we also discuss the effects of anti-inflammatory drugs and antioxidants in basic studies on animals and clinical studies of ASD. Our review provides the latest findings and new insights into the involvements of inflammation and oxidative stress in the pathogenesis of ASD.

Deoxyshikonin inhibited rotavirus replication by regulating autophagy and oxidative stress through SIRT1/FoxO1/Rab7 axis

BACKGROUND

Rotavirus (RV) is a double-stranded RNA virus. RV prevention and treatment remain a major public health problem due to the lack of clinically specific drugs. Deoxyshikonin is a natural compound isolated from the root of Lithospermum erythrorhizon and one of the shikonin derivatives which owns remarkable therapeutic effects on multiple diseases. The purpose of this research was to inquire Deoxyshikonin's role and mechanism in RV infection.

METHODS

Deoxyshikonin's function in RV was estimated using Cell Counting Kit-8 analysis, cytopathic effect inhibition assay, virus titer determination, quantitative real-time PCR, enzyme linked-immunosorbent assay, Western blot, immunofluorescence, and glutathione levels detection. Also, Deoxyshikonin's mechanism in RV was appraised with Western blot, virus titer determination, and glutathione levels detection. Moreover, Deoxyshikonin's function in RV in vivo was determined using animal models, and diarrhea score analysis.

RESULTS

Deoxyshikonin owned anti-RV activity and repressed RV replication in Caco-2 cells. Furthermore, Deoxyshikonin reduced autophagy and oxidative stress caused by RV. Mechanistically, Deoxyshikonin induced low protein levels of SIRT1, ac-Foxo1, Rab7, VP6, low levels of RV titers, low autophagy and oxidative stress. SIRT1 overexpression abolished the effects of Deoxyshikonin on RV-treated Caco-2 cells. Meanwhile, in vivo research affirmed that Deoxyshikonin also possessed anti-RV function, and this was reflected in increased survival rate, body weight, GSH levels, and decreased diarrhea score, RV virus antigen, LC-3II/LC3-I.

CONCLUSION

Deoxyshikonin reduced RV replication through mediating autophagy and oxidative stress via SIRT1/FoxO1/Rab7 pathway.

Reactive oxygen species and ovarian diseases: Antioxidant strategies

Reactive oxygen species (ROS) are mainly produced in mitochondria and are involved in various physiological activities of the ovary through signaling and are critical for regulating the ovarian cycle. Notably, the imbalance between ROS generation and the antioxidant defense system contributes to the development of ovarian diseases. These contradictory effects have critical implications for potential antioxidant strategies that aim to scavenge excessive ROS. However, much remains to be learned about how ROS causes various ovarian diseases to the application of antioxidant therapy for ovarian diseases. Here, we review the mechanisms of ROS generation and maintenance of homeostasis in the ovary and its associated physiological effects. Additionally, we have highlighted the pathological mechanisms of ROS in ovarian diseases and potential antioxidant strategies for treatment.

Serum free thiols in recently diagnosed patients with schizophrenia spectrum disorder: A potentially useful biomarker of oxidative stress

Schizophrenia spectrum disorders (SSD) have been linked to oxidative stress (OS). Recent findings from our group show that serum free thiols (R-SH, sulfhydryl groups) can function as an accurate biomarker of systemic OS, since they are readily oxidized by reactive species (ROS), thereby serving as potent antioxidants. The aim of this study is to investigate if reduced R-SH levels can be demonstrated in recently diagnosed patients with SSD compared to healthy controls (HC). In this study, 102 patients with recently diagnosed SSD (< three years), and 42 HC were included. Levels of R-SH were quantified and studied for correlations with age, C-reactive protein (CRP) as proxy of inflammation as well as body mass index (BMI) and total cholesterol as indices of metabolic health. R-SH levels were significantly lower in patients when compared to HC. When correcting for age the difference was borderline significant (p=0.05). Moreover, R-SH correlated significantly with age (r = -0.29) and CRP (r = -0.29) in patients with SSD, but not in the HC. R-SH levels are reduced in SSD as compared to HC and correlate negatively with CRP and age in SSD. Future studies are required to further investigate R-SH and its role in SSD.

Glutathione system enhancement for cardiac protection: pharmacological options against oxidative stress and ferroptosis

The glutathione (GSH) system is considered to be one of the most powerful endogenous antioxidant systems in the cardiovascular system due to its key contribution to detoxifying xenobiotics and scavenging overreactive oxygen species (ROS). Numerous investigations have suggested that disruption of the GSH system is a critical element in the pathogenesis of myocardial injury. Meanwhile, a newly proposed type of cell death, ferroptosis, has been demonstrated to be closely related to the GSH system, which affects the process and outcome of myocardial injury. Moreover, in facing various pathological challenges, the mammalian heart, which possesses high levels of mitochondria and weak antioxidant capacity, is susceptible to oxidant production and oxidative damage. Therefore, targeted enhancement of the GSH system along with prevention of ferroptosis in the myocardium is a promising therapeutic strategy. In this review, we first systematically describe the physiological functions and anabolism of the GSH system, as well as its effects on cardiac injury. Then, we discuss the relationship between the GSH system and ferroptosis in myocardial injury. Moreover, a comprehensive summary of the activation strategies of the GSH system is presented, where we mainly identify several promising herbal monomers, which may provide valuable guidelines for the exploration of new therapeutic approaches.

The effect of co-administration of artemisinin and N-acetyl cysteine on antioxidant status, spermatological parameters and histopathology of testis in adult male mice

OBJECTIVES

This in vivo study aimed to evaluate the effect of various concentrations of artemisinin (Art) alone or together with N-acetyl cysteine (NAC) on spermatological indices, antioxidant status, and histopathological parameters of testicular tissue in adult male mice.

METHODS

Six groups of five healthy male mice (25-30 g) were randomly assigned to different experimental groups. These groups received DMSO and corn oil (0.1%) as an Art solvent (Control), 50 mg kg^-1 Art (Art-50), 250 mg kg^-1 Art (Art-250), 50 mg kg^-1 Art + 150 mg kg^-1 NAC (Art-50+NAC-150), 250 mg kg^-1 Art + 150 mg kg^-1 NAC (Art-250+NAC-150) and 150 mg kg^-1 NAC (NAC-150) for a period of 7 days. Testes and epididymis were prepared to evaluate the malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), spermatological indices, and histological parameters.

RESULTS

We showed that the high dose of Art (Art-250) significantly reduced the sperm count, motility, viability, and the activity of CAT and increased the levels of MDA compared to the control group. Also, the overdose of Art caused adverse changes in testicular tissue. Co-administration of NAC with Art (Art-250+NAC-150) corrected the adverse effects of Art.

CONCLUSIONS

The current study reports that a high dose of Art affects, spermatological parameters, antioxidant/stress oxidative status of the male reproductive system, and NAC is capable neutralize all adverse effects caused by Art.

Potential Role of Superoxide Dismutase 3 (SOD3) in Resistance to Influenza A Virus Infection

Influenza A virus infection induces the production of excessive reactive oxygen species (ROS). Overproduction of ROS can overwhelm the antioxidant defense system, leading to increasing intensive oxidative stress. However, antioxidant defense against oxidative damage induced by influenza A virus infection, and in particular the significance of the SOD3 response in the pathogenesis of influenza virus infection, has not been well characterized. Here, we investigated the potential role of SOD3 in resistance to influenza A virus infection. In this study, SOD3, as an important antioxidant enzyme, was shown to be highly elevated in A549 cells following influenza A virus infection. Furthermore, inhibition of SOD3 impacted viral replication and virulence. We found that SOD3 disrupts IAV replication by impairing the synthesis of vRNA, whereas it did not affect viral ribonucleoprotein nuclear export. In addition, overexpression of SOD3 greatly reduced the levels of ROS caused by influenza A virus infection, regulated the inflammatory response to virus infection by inhibiting the phosphorylation of p65 of the NF-κB signaling pathway, and inhibited virus-induced apoptosis to a certain extent. Taken together, these findings indicate that SOD3 is actively involved in influenza A virus replication. Pharmacological modulation or targeting of SOD3 may pave the way for a novel therapeutic approach to combating influenza A virus infection.

Ferroptosis is critical for phthalates driving the blood-testis barrier dysfunction via targeting transferrin receptor

The global rate of human male infertility is rising at an alarming rate owing to environmental and lifestyle changes. Phthalates are the most hazardous chemical additives in plastics and have an apparently negative impact on the function of male reproductive system. Ferroptosis is a recently described form of iron-dependent cell death and has been linked to several diseases. Transferrin receptor (TfRC), a specific ferroptosis marker, is a universal iron importer for all cells using extracellular transferrin. We aim to investigate the potential involvement of ferroptosis during male reproductive toxicity, and provide means for drawing conclusions on the effect of ferroptosis in phthalates-induced male reproductive disease. In this study, we found that di (2-ethylhexyl) phthalate (DEHP) triggered blood-testis barrier (BTB) dysfunction in the mouse testicular tissues. DEHP also induced mitochondrial morphological changes and lipid peroxidation, which are manifestations of ferroptosis. As the primary metabolite of DEHP, mono-2-ethylhexyl phthalate (MEHP) induced ferroptosis by inhibiting glutathione defense network and increasing lipid peroxidation. TfRC knockdown blocked MEHP-induced ferroptosis by decreasing mitochondrial and intracellular levels of Fe²⁺. Our findings indicate that TfRC can regulate Sertoli cell ferroptosis and therefore is a novel therapeutic molecule for reproductive disorders in male patients with infertility.

Development of spray-dried N-acetylcysteine dry powder for inhalation

N-acetylcysteine (NAC) has both antioxidant and immunomodulatory activities and has been used as adjuvant therapy in several viral infections. Recently, NAC attracted attention for its possible role in reducing the affinity of the spike protein receptor binding domain to angiotensin-converting enzyme (ACE2) receptors. Since only NAC solutions are available for inhalation, the purpose of the work was to develop a NAC dry powder for inhalation using mannitol or leucine as excipient. The powder was successfully produced using co-spray-drying with leucine. ATR-FTIR analyses evidenced spectral variations ascribed to the formation of specific interactions between NAC and leucine. This effect on the NAC environment was not evident for NAC-mannitol powders, but mannitol was in a different polymorphic form compared to the supplied material. Both the feedstock concentration and the leucine content have an impact on the powder aerodynamic features. In particular, to maximize the respirable fraction, it is preferable to produce the powder starting from a 0.5 % w/v feedstock solution using 33 to 50 % w/w leucine content. The NAC-leucine powder was stable for ten months maintaining NAC content of 50 % (w/w) and about 200 μg of NAC was able to deposit on a transwell insert, useful for future in vitro studies.

Effects of NAC assisted insulin on cholesterol metabolism disorders in canine type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is a metabolic disease characterized by insulin deficiency and often accompanied by hypercholesterolemia. NAC is an effective antioxidative drug, but its application in the treatment of diabetes is still rare. A total of forty beagles were randomly divided into five groups: control group, DM group, INS group, INS with NAC group, and NAC group. The experiment lasted for 120 days. Results revealed that biochemical criterion increased in the DM group, while the indicators significantly decreased on the INS combined with NAC treatment group. Moreover, the insulin released test demonstrated that the model of T1DM was successfully constructed. The result of B ultrasound of gallbladder showed remarkable cholestasis in DM group. The cholesterol metabolism-related enzyme activity (HMGCR and SQLE) was evidently increased in DM group, but decreased in INS and NAC group. The content of TG, LDL-c, and HDL-c in liver was detected by the kit, and it was found that the content of TG, LDL-c, and HDL-c in DM group were reduced. Histopathological observation revealed that the cholestasis of liver cells and hepatic cords were disordered in DM group, the symptoms were alleviated under INS and NAC treatment. Additionally, the protein and mRNA expression of HMGCR and LDLR were obviously increased in DM group, but down regulated in INS and NAC treatment group. Overall, the liver function injury and secondary hypercholesterolemia can be found in T1DM canines, and NAC can relieve cholesterol metabolism disorder in the treatment of canine T1DM.

A Multifunctional Dental Resin Composite with Sr-N-Doped TiO2 and n-HA Fillers for Antibacterial and Mineralization Effects

Dental caries, particularly secondary caries, which is the main contributor to dental repair failure, has been the subject of extensive research due to its biofilm-mediated, sugar-driven, multifactorial, and dynamic characteristics. The clinical utility of restorations is improved by cleaning bacteria nearby and remineralizing marginal crevices. In this study, a novel multifunctional dental resin composite (DRC) composed of Sr-N-co-doped titanium dioxide (Sr-N-TiO2) nanoparticles and nano-hydroxyapatite (n-HA) reinforcing fillers with improved antibacterial and mineralization properties is proposed. The experimental results showed that the anatase-phase Sr-N-TiO2 nanoparticles were synthesized successfully. After this, the curing depth (CD) of the DRC was measured from 4.36 ± 0.18 mm to 5.10 ± 0.19 mm, which met the clinical treatment needs. The maximum antibacterial rate against Streptococcus mutans (S. mutans) was 98.96%, showing significant inhibition effects (p < 0.0001), which was experimentally verified to be derived from reactive oxygen species (ROS). Meanwhile, the resin exhibited excellent self-remineralization behavior in an SBF solution, and the molar ratio of Ca/P was close to that of HA. Moreover, the relative growth rate (RGR) of mouse fibroblast L929 indicated a high biocompatibility, with the cytotoxicity level being 0 or I. Therefore, our research provides a suitable approach for improving the antibacterial and mineralization properties of DRCs.

N-Acetylcysteine: more than preventing contrast-induced nephropathy in uremic patients-focus on the antioxidant and anti-inflammatory properties

Oxidative stress (OS) has been recognized as a pathophysiologic mechanism underlying the development and progression of chronic kidney disease (CKD). OS, which results from the disturbance of balance among pro-oxidants and antioxidants favoring the pro-oxidants, is present even in early CKD and increases progressively along with deterioration of kidney function to end-stage kidney disease (ESKD). In ESKD, OS is further exacerbated mainly due to dialysis procedures per se and predisposes to increased cardiovascular morbidity and mortality. Therefore, since OS plays a pivotal role in the pathogenesis and progression of atherosclerosis in uremic patients, several strategies aiming to ameliorate OS in these patients have been proposed. Among those, N-acetylcysteine (NAC), a thiol-containing antioxidant agent, has attracted special attention due to its pleiotropic functions and beneficial effect in various OS-related entities including paracetamol overdose and prevention of contrast-induced nephropathy. In this review, we present the currently available literature on the antioxidant and anti-inflammatory properties of NAC in CKD, including hemodialysis and peritoneal dialysis.

Large paracetamol overdose-Higher dose acetylcysteine is required

Paracetamol poisoning continues to be a worldwide problem and, despite the availability of an effective antidote, acetylcysteine (NAC), the optimal way to use this antidote, particularly following very large doses of paracetamol, has not been established. Recent case series have shown an increased toxicity from high doses of paracetamol, even in those receiving prompt NAC therapy, particularly in patients above the 300 mg/L nomogram treatment line. Clinical trial evidence supporting shorter NAC dosing now allows the possibility for intensifying treatment without the risk of very high rates of ADRs. New biomarkers also show the possibility of early identification of patients at risk of liver injury who might also benefit from increased intensity treatment. This article discusses these data and proposes a logical therapy for increasing NAC dosing which now requires clinical trial testing.

Sexually concordant and dimorphic transcriptional responses to maternal trichloroethylene and/or N-acetyl cysteine exposure in Wistar rat placental tissue

Numerous Superfund sites are contaminated with the volatile organic chemical trichloroethylene (TCE). In women, exposure to TCE in pregnancy is associated with reduced birth weight. Our previous study reported that TCE exposure in pregnant rats decreased fetal weight and elevated oxidative stress biomarkers in placentae, suggesting placental injury as a potential mechanism of TCE-induced adverse birth outcomes. In this study, we investigated if co-exposure with the antioxidant N-acetylcysteine (NAC) attenuates TCE exposure effects on RNA expression. Timed-pregnant Wistar rats were exposed orally to 480 mg TCE/kg/day on gestation days 6-16. Exposure of 200 mg NAC/kg/day alone or as a pre/co-exposure with TCE occurred on gestation days 5-16 to stimulate antioxidant genes prior to TCE exposure. Tissue was collected on gestation day 16. In male and female placentae, we evaluated TCE- and/or NAC-induced changes to gene expression and pathway enrichment analyses using false discovery rate (FDR) and fold-change criteria. In female placentae, exposure to TCE caused significant differential expression 129 genes while the TCE+NAC altered 125 genes, compared with controls (FDR< 0.05 + fold-change >1). In contrast, in male placentae TCE exposure differentially expressed 9 genes and TCE+NAC differentially expressed 35 genes, compared with controls (FDR< 0.05 + fold-change >1). NAC alone did not significantly alter gene expression in either sex. Differentially expressed genes observed with TCE exposure were enriched in mitochondrial biogenesis and oxidative phosphorylation pathways in females whereas immune system pathways and endoplasmic reticulum stress pathways were differentially expressed in both sexes (FDR<0.05). TCE treatment was differentially enriched for genes regulated by the transcription factors ATF6 (both sexes) and ATF4 (males only), indicating a cellular condition triggered by misfolded proteins during endoplasmic reticulum stress. This study demonstrates novel genes and pathways involved in TCE-induced placental injury and showed antioxidant co-treatment largely did not attenuate TCE exposure effects.

Design and rationale for the prospective treatment efficacy in IPF using genotype for NAC selection (PRECISIONS) clinical trial

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with few treatment options. N-acetylcysteine (NAC) is a well-tolerated, inexpensive treatment with antioxidant and anti-fibrotic properties. The National Heart, Lung, and Blood Institute (NHLBI)-sponsored PANTHER (Prednisone Azathioprine and NAC therapy in IPF) trial confirmed the harmful effects of immunosuppression in IPF, and did not show a benefit to treatment with NAC. However, a post hoc analysis revealed a potential beneficial effect of NAC in a subgroup of individuals carrying a specific genetic variant, TOLLIP rs3750920 TT genotype, present in about 25% of patients with IPF. Here, we present the design and rationale for the Phase III, multi-center, randomized, double-blind, placebo-controlled Prospective Treatment Efficacy in IPF Using Genotype for NAC Selection (PRECISIONS) clinical trial.

METHODS

The PRECISIONS trial will randomize 200 patients with IPF and the TOLLIP rs3750920 TT genotype 1:1 to oral N-acetylcysteine (600 mg tablets taken three times a day) or placebo for a 24-month duration. The primary endpoint is the composite of time to 10% relative decline in forced vital capacity (FVC), first respiratory hospitalization, lung transplantation, or death from any cause. Secondary endpoints include change in patient-reported outcome scores and proportion of participants with treatment-emergent adverse events. Biospecimens, including blood, buccal, and fecal will be collected longitudinally for future research purposes. Study participants will be offered enrollment in a home spirometry substudy, which explores time to 10% relative FVC decline measured at home, and its comparison with study visit FVC.

DISCUSSION

The sentinel observation of a potential pharmacogenetic interaction between NAC and TOLLIP polymorphism highlights the urgent, unmet need for better, molecularly focused, and precise therapeutic strategies in IPF. The PRECISIONS clinical trial is the first study to use molecularly-focused techniques to identify patients with IPF most likely to benefit from treatment. PRECISIONS has the potential to shift the paradigm in how trials in this condition are designed and executed, and is the first step toward personalized medicine for patients with IPF. Trial Registration ClinicalTrials.gov identifier: NCT04300920. Registered March 9, 2020. https://clinicaltrials.gov/ct2/show/NCT04300920.

Metabolic enhancement of the one carbon metabolism (OCM) in bovine oocytes IVM increases the blastocyst rate: evidences for a OCM checkpoint

The one carbon metabolism (OCM) has a primary role in the process of oocyte maturation. In this study bovine oocytes were cultured for 24 h, up to MII stage, with standard medium supplemented or not with 8 metabolic enhancers of the OCM and the MII and blastocyst rate were compared. Additional analyses were performed on matured oocytes, cumulus cells, zygotes and blastocysts. The OCM supplementation increased the blastocyst rate derived from in vitro fertilization. The mitochondrial mass and DNMT3a protein expression were increased whereas DNA fragmentation decreased in matured oocytes. DNA methylation in female pronucleus of zygotes was increased. The supplementation did not directly affect the redox balance as ROS and GSH in matured oocytes and homocysteine in the spent medium were unchanged. The supplementation of the oocytes with metabolic enhancers of the OCM may increase the yield from the culture, likely due to improved DNA methylation and epigenetic programming. The lack of effects on MII rate with huge differences appearing at the blastocyst stage suggest the existence of a OCM metabolic check point that hampers oocytes progression to blastocyst post-fertilization, if they were not properly primed at the time of maturation.

High-Altitude Hypoxia Exposure Induces Iron Overload and Ferroptosis in Adipose Tissue

High altitude (HA) has become one of the most challenging environments featuring hypobaric hypoxia, which seriously threatens public health, hence its gradual attraction of public attention over the past decade. The purpose of this study is to investigate the effect of HA hypoxia on iron levels, redox state, inflammation, and ferroptosis in adipose tissue. Here, 40 mice were randomly divided into two groups: the sea-level group and HA hypoxia group (altitude of 5000 m, treatment for 4 weeks). Total iron contents, ferrous iron contents, ROS generation, lipid peroxidation, the oxidative enzyme system, proinflammatory factor secretion, and ferroptosis-related biomarkers were examined, respectively. According to the results, HA exposure increases total iron and ferrous iron levels in both WAT and BAT. Meanwhile, ROS release, MDA, 4-HNE elevation, GSH depletion, as well as the decrease in SOD, CAT, and GSH-Px activities further evidenced a phenotype of redox imbalance in adipose tissue during HA exposure. Additionally, the secretion of inflammatory factors was also significantly enhanced in HA mice. Moreover, the remarkably changed expression of ferroptosis-related markers suggested that HA exposure increased ferroptosis sensitivity in adipose tissue. Overall, this study reveals that HA exposure is capable of inducing adipose tissue redox imbalance, inflammatory response, and ferroptosis, driven in part by changes in iron overload, which is expected to provide novel preventive targets for HA-related illness.

Identification of Canine Pyometra-Associated Metabolites Using Untargeted Metabolomics

Canine pyometra frequently occurs in middle-aged to older intact bitches, which seriously affects the life of dogs and brings an economic loss to their owners. Hence, finding a key metabolite is very important for the diagnosis and development of a new safe and effective therapy for the disease. In this study, dogs with pyometra were identified by blood examinations, laboratory analyses and diagnostic imaging, and fifteen endometrium tissues of sick dogs with pyometra and fifteen controls were collected and their metabolites were identified utilizing a UHPLC-qTOF-MS-based untargeted metabolomics approach. The results indicated that the elevated inflammatory cells were observed in dogs with pyometra, suggesting that sick dogs suffered systemic inflammation. In the untargeted metabolic profile, 705 ion features in the positive polarity mode and 414 ion features in the negative polarity mode were obtained in endometrium tissues of sick dogs with pyometra, with a total of 275 differential metabolites (173 in positive and 102 in negative polarity modes). Moreover, the multivariate statistical analyses such as PCA and PLS-DA also showed that the metabolites were significantly different between the two groups. Then, these differential metabolites were subjected to pathway analysis using Metaboanalyst 4.0, and Galactose metabolism, cAMP signaling pathway and Glycerophospholipid metabolism were enriched, proving some insights into the metabolic changes during pyometra. Moreover, the receiver operating characteristic curves further confirmed kynurenic acid was expected to be a candidate biomarker of canine pyometra. In conclusion, this study provided a new idea for exploring early diagnosis methods and a safe and effective therapy for canine pyometra.

The Renin-Angiotensin-Aldosterone System, Nitric Oxide, and Hydrogen Sulfide at the Crossroads of Hypertension and COVID-19: Racial Disparities and Outcomes

Coronavirus disease 2019 is caused by SARS-CoV-2 and is more severe in the elderly, racial minorities, and those with comorbidities such as hypertension and diabetes. These pathologies are often controlled with medications involving the renin-angiotensin-aldosterone system (RAAS). RAAS is an endocrine system involved in maintaining blood pressure and blood volume through components of the system. SARS-CoV-2 enters the cells through ACE2, a membrane-bound protein related to RAAS. Therefore, the use of RAAS inhibitors could worsen the severity of COVID-19's symptoms, especially amongst those with pre-existing comorbidities. Although a vaccine is currently available to prevent and reduce the symptom severity of COVID-19, other options, such as nitric oxide and hydrogen sulfide, may also have utility to prevent and treat this virus.

Lpcat3 deficiency promotes palmitic acid-induced 3T3-L1 mature adipocyte inflammation through enhanced ROS generation

Phosphatidylcholines (PCs) are major phospholipids in the mammalian cell membrane. Structural remodeling of PCs is associated with many biological processes. Lysophosphatidylcholine acyltransferase 3 (Lpcat3), which catalyzes the incorporation of polyunsaturated fatty acyl chains into the sn-2 site of PCs, plays an important role in maintaining plasma membrane fluidity. Adipose tissue is one of the main distribution organs of Lpcat3, while the relationship between Lpcat3 and adipose tissue dysfunction during overexpansion remains unknown. In this study, we reveal that both polyunsaturated PC content and Lpcat3 expression are increased in abdominal adipose tissues of high-fat diet-fed mice when compared with chow-diet-fed mice, indicating that Lpcat3 is involved in adipose tissue overexpansion and dysfunction. Our experiments in 3T3-L1 adipocytes show that inhibition of Lpcat3 does not change triglyceride accumulation but increases palmitic acid-induced inflammation and lipolysis. Conversely, Lpcat3 overexpression exhibits anti-inflammatory and anti-lipolytic effects. Furthermore, mechanistic studies demonstrate that Lpcat3 deficiency promotes reactive oxygen species (ROS) generation by increasing NOX enzyme activity by facilitating the translocation of NOX4 to lipid rafts, thereby aggregating 3T3-L1 adipocyte inflammation induced by palmitic acid. Moreover, overexpression of Lpcat3 exhibits the opposite effects. These findings suggest that Lpcat3 protects adipocytes from inflammation during adipose tissue overexpansion by reducing ROS generation. In conclusion, our study demonstrates that Lpcat3 deficiency promotes palmitic acid-induced inflammation in 3T3-L1 adipocytes by enhancing ROS generation.

Ultrasmall iron-quercetin metal natural product nanocomplex with antioxidant and macrophage regulation in rheumatoid arthritis

Oxidative stress, due to the disruption of the balance between reactive oxygen species (ROS) generation and the antioxidant defense system, plays an important role in the pathogenesis of rheumatoid arthritis (RA). Excessive ROS leads to the loss of biological molecules and cellular functions, release of many inflammatory mediators, stimulate the polarization of macrophages, and aggravate the inflammatory response, thus promoting osteoclasts and bone damage. Therefore, foreign antioxidants would effectively treat RA. Herein, ultrasmall iron-quercetin natural coordination nanoparticles (Fe-Qur NCNs) with excellent anti-inflammatory and antioxidant properties were constructed to effectively treat RA. Fe-Qur NCNs obtained by simple mixing retain the inherent ability to remove ROS of quercetin and have a better water-solubility and biocompatibility. In vitro experiments showed that Fe-Qur NCNs could effectively remove excess ROS, avoid cell apoptosis, and inhibit the polarization of inflammatory macrophages by reducing the activation of the nuclear factor-κ-gene binding (NF-κB) pathways. In vivo experiments showed that the swollen joints of mice with rheumatoid arthritis treated with Fe-Qur NCNs significantly improved, with Fe-Qur NCNs largely reducing inflammatory cell infiltration, increasing anti-inflammatory macrophage phenotypes, and thus inhibiting osteoclasts, which led to bone erosion. This study demonstrated that the new metal-natural coordination nanoparticles could be an effective therapeutic agent for the prevention of RA and other diseases associated with oxidative stress.

Cardiac and respiratory muscle responses to dietary N-acetylcysteine in rats consuming a high-saturated fat, high-sucrose diet

NEW FINDINGS

What is the central question of this study? This study addresses whether a high-fat, high-sucrose diet causes cardiac and diaphragm muscle abnormalities in male rats and whether supplementation with the antioxidant N-acetylcysteine reverses diet-induced dysfunction. What is the main finding and its importance? N-Acetylcysteine attenuated the effects of high-fat, high-sucrose diet on markers of cardiac hypertrophy and diastolic dysfunction, but neither high-fat, high-sucrose diet nor N-acetylcysteine affected the diaphragm. These results support the use of N-acetylcysteine to attenuate cardiovascular dysfunction induced by a 'Western' diet.

ABSTRACT

Individuals with overweight or obesity display respiratory and cardiovascular dysfunction, and oxidative stress is a causative factor in the general aetiology of obesity and of skeletal and cardiac muscle pathology. Thus, this preclinical study aimed to define diaphragmatic and cardiac morphological and functional alterations in response to an obesogenic diet in rats and the therapeutic potential of an antioxidant supplement, N-acetylcysteine (NAC). Young male Wistar rats consumed ad libitum a 'lean' or high-saturated fat, high-sucrose (HFHS) diet for ∼22 weeks and were randomized to control or NAC (2 mg/ml in the drinking water) for the last 8 weeks of the dietary intervention. We then evaluated diaphragmatic and cardiac morphology and function. Neither HFHS diet nor NAC supplementation affected diaphragm-specific force, peak power or morphology. Right ventricular weight normalized to estimated body surface area, left ventricular fractional shortening and posterior wall maximal shortening velocity were higher in HFHS compared with lean control animals and not restored by NAC. In HFHS rats, the elevated deceleration rate of early transmitral diastolic velocity was prevented by NAC. Our data showed that the HFHS diet did not compromise diaphragmatic muscle morphology or in vitro function, suggesting other possible contributors to breathing abnormalities in obesity (e.g., abnormalities of neuromuscular transmission). However, the HFHS diet resulted in cardiac functional and morphological changes suggestive of hypercontractility and diastolic dysfunction. Supplementation with NAC did not affect diaphragm morphology or function but attenuated some of the cardiac abnormalities in the rats receiving the HFHS diet.

Hydrogenated Germanene Nanosheets as an Antioxidative Defense Agent for Acute Kidney Injury Treatment

Acute kidney injury (AKI) is a sudden kidney dysfunction caused by aberrant reactive oxygen species (ROS) metabolism that results in high clinical mortality. The rapid development of ROS scavengers provides new opportunities for AKI treatment. Herein, the use of hydrogen-terminated germanene (H-germanene) nanosheets is reported as an antioxidative defense nanoplatform against AKI in mice. The simulation results show that 2D H-germanene can effectively scavenge ROS through free radical adsorption and subsequent redox reactions. In particular, the H-germanene exhibits high accumulation in injured kidneys, thereby offering a favorable opportunity for treating renal diseases. In the glycerol-induced murine AKI model, H-germanene delivers robust antioxidative protection against ROS attack to maintain normal kidney function indicators without negative influence in vivo. This positive in vivo antioxidative defense in living animals demonstrates that the present H-germanene nanoplatform is a powerful antioxidant against AKI and various anti-inflammatory diseases.

Hydrogenated Germanene Nanosheets as an Antioxidative Defense Agent for Acute Kidney Injury Treatment

Acute kidney injury (AKI) is a sudden kidney dysfunction caused by aberrant reactive oxygen species (ROS) metabolism that results in high clinical mortality. The rapid development of ROS scavengers provides new opportunities for AKI treatment. Herein, the use of hydrogen‐terminated germanene (H‐germanene) nanosheets is reported as an antioxidative defense nanoplatform against AKI in mice. The simulation results show that 2D H‐germanene can effectively scavenge ROS through free radical adsorption and subsequent redox reactions. In particular, the H‐germanene exhibits high accumulation in injured kidneys, thereby offering a favorable opportunity for treating renal diseases. In the glycerol‐induced murine AKI model, H‐germanene delivers robust antioxidative protection against ROS attack to maintain normal kidney function indicators without negative influence in vivo. This positive in vivo antioxidative defense in living animals demonstrates that the present H‐germanene nanoplatform is a powerful antioxidant against AKI and various anti‐inflammatory diseases.

Glutathione deficiency in the pathogenesis of SARS-CoV-2 infection and its effects upon the host immune response in severe COVID-19 disease

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 19 (COVID-19) has numerous risk factors leading to severe disease with high mortality rate. Oxidative stress with excessive production of reactive oxygen species (ROS) that lower glutathione (GSH) levels seems to be a common pathway associated with the high COVID-19 mortality. GSH is a unique small but powerful molecule paramount for life. It sustains adequate redox cell signaling since a physiologic level of oxidative stress is fundamental for controlling life processes via redox signaling, but excessive oxidation causes cell and tissue damage. The water-soluble GSH tripeptide (γ-L-glutamyl-L-cysteinyl-glycine) is present in the cytoplasm of all cells. GSH is at 1–10 mM concentrations in all mammalian tissues (highest concentration in liver) as the most abundant non-protein thiol that protects against excessive oxidative stress. Oxidative stress also activates the Kelch-like ECH-associated protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) redox regulator pathway, releasing Nrf2 to regulate the expression of genes that control antioxidant, inflammatory and immune system responses, facilitating GSH activity. GSH exists in the thiol-reduced and disulfide-oxidized (GSSG) forms. Reduced GSH is the prevailing form accounting for >98% of total GSH. The concentrations of GSH and GSSG and their molar ratio are indicators of the functionality of the cell and its alteration is related to various human pathological processes including COVID-19. Oxidative stress plays a prominent role in SARS-CoV-2 infection following recognition of the viral S-protein by angiotensin converting enzyme-2 receptor and pattern recognition receptors like toll-like receptors 2 and 4, and activation of transcription factors like nuclear factor kappa B, that subsequently activate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) expression succeeded by ROS production. GSH depletion may have a fundamental role in COVID-19 pathophysiology, host immune response and disease severity and mortality. Therapies enhancing GSH could become a cornerstone to reduce severity and fatal outcomes of COVID-19 disease and increasing GSH levels may prevent and subdue the disease. The life value of GSH makes for a paramount research field in biology and medicine and may be key against SARS-CoV-2 infection and COVID-19 disease.

Vascular Calcification: In Vitro Models under the Magnifying Glass

Vascular calcification is a systemic disease contributing to cardiovascular morbidity and mortality. The pathophysiology of vascular calcification involves calcium salt deposition by vascular smooth muscle cells that exhibit an osteoblast-like phenotype. Multiple conditions drive the phenotypic switch and calcium deposition in the vascular wall; however, the exact molecular mechanisms and the connection between vascular smooth muscle cells and other cell types are not fully elucidated. In this hazy landscape, effective treatment options are lacking. Due to the pathophysiological complexity, several research models are available to evaluate different aspects of the calcification process. This review gives an overview of the in vitro cell models used so far to study the molecular processes underlying vascular calcification. In addition, relevant natural and synthetic compounds that exerted anticalcifying properties in in vitro systems are discussed.