The chemistry and biological activities of N-acetylcysteine

Successful Recovery of Cardiac Function Following 20 min of a No-touch Period in a Donation After Circulatory Death: A Case Report

BACKGROUND

Withdrawal of life-sustaining therapy (WLST) performed in the circulatory determination of death (DCD) donors leads to cardiac arrest, challenging the utilization of the myocardium for transplantation. The rapid initiation of normothermic regional perfusion or extracorporeal membrane oxygenation after death helps to optimize organs before implantation. However, additional strategies to mitigate the effects of stress response during WLST, hypoxic/ischemic injury, and reperfusion injury are required to allow myocardium recovery.

METHODS

To this aim, our team routinely used a preconditioning protocol for each DCD donation before and during the WLST and after normothermic regional perfusion/extracorporeal membrane oxygenation. The protocol includes pharmacological treatments combined to reduce oxidative stress (melatonin, N -acetylcysteine, and ascorbic acid), improve microcirculation (statins), and mitigate organ's ischemic injury (steroids) and organ ischemia/reperfusion injury (remifentanil and sevoflurane when the heart is available for transplantation).

RESULTS

This report presents the first case of recovery of cardiac function, with the only support of normothermic regional reperfusion, following 20 min of a no-touch period and 41 min of functional warm ischemic time in a DCD donor after the preconditioning protocol.

CONCLUSIONS

Our protocol seems to be effective in abolishing the stress response during WLST and, on the other hand, particularly organ protective (and heart protective), giving a chance to donate organs less impaired from ischemia/reperfusion injury.

Intrinsic antimicrobial resistance: Molecular biomaterials to combat microbial biofilms and bacterial persisters

The escalating rise in antimicrobial resistance (AMR) coupled with a declining arsenal of new antibiotics is imposing serious threats to global public health. A pervasive aspect of many acquired AMR infections is that the pathogenic microorganisms exist as biofilms, which are equipped with superior survival strategies. In addition, persistent and recalcitrant infections are seeded with bacterial persister cells at infection sites. Together, conventional antibiotic therapeutics often fail in the complete treatment of infections associated with bacterial persisters and biofilms. Novel therapeutics have been attempted to tackle AMR, biofilms, and persister-associated complex infections. This review focuses on the progress in designing molecular biomaterials and therapeutics to address acquired and intrinsic AMR, and the fundamental microbiology behind biofilms and persisters. Starting with a brief introduction of AMR basics and approaches to tackling acquired AMR, the emphasis is placed on various biomaterial approaches to combating intrinsic AMR, including (1) semi-synthetic antibiotics; (2) macromolecular or polymeric biomaterials mimicking antimicrobial peptides; (3) adjuvant effects in synergy; (4) nano-therapeutics; (5) nitric oxide-releasing antimicrobials; (6) antimicrobial hydrogels; (7) antimicrobial coatings. Particularly, the structure-activity relationship is elucidated in each category of these biomaterials. Finally, illuminating perspectives are provided for the future design of molecular biomaterials to bypass AMR and cure chronic multi-drug resistant (MDR) infections.

Prophylactic Effects of n-Acethylcysteine on Inflammation-induced Depression-like Behaviors in Mice

Depression, affecting individuals worldwide, is a prevalent mental disease, with an increasing incidence. Numerous studies have been conducted on depression, yet its pathogenesis remains elusive. Recent advancements in research indicate that disturbances in synaptic transmission, synaptic plasticity, and reduced neurotrophic factor expression significantly contribute to depression's pathogenesis. In our study, we utilized adult male C57BL/6J mice. Lipopolysaccharide (LPS) can induce both chronic and acute depression-like symptoms in mice, a widely used model for studying depression associated with inflammation. N-acetylcysteine (NAC) exhibits anti-inflammatory and ameliorative effects on depressive symptoms. This study sought to determine whether NAC use could mitigate inflammatory depressive behavior through the enhancement of synaptic transmission, synaptic plasticity, and increasing levels of brain-derived neurotrophic factor (BDNF). In this study, we discovered that in mice modeled with depression-like symptoms, the expression levels of dendrites, BDNF, and miniature excitatory postsynaptic potential (mEPSC) in glutamatergic neurons, as well as the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid glutamate receptors (AMPARs) GluA1 and GluA2 subunits, were significantly decreased. These findings suggest an impairment in the synaptic transmission of glutamatergic neurons. Following treatment with NAC, the previously mentioned levels improved, indicating an enhancement in both synaptic transmission and synaptic plasticity. Our results suggest that NAC exerts a protective effect on mouse models of inflammatory depression, potentially through the enhancement of synaptic transmission and plasticity, as well as the restoration of neurotrophic factor expression. These findings offer vital animal experimental evidence supporting NAC's role in mitigating inflammatory depressive behaviors.

The effect of N-acetylcysteine on the neurotoxicity of sevoflurane in developing hippocampus cells

Sevoflurane, a common pediatric anesthetic, has been linked to neurodegeneration, raising safety concerns. This study explored N-acetylcysteine's protective potential against sevoflurane-induced neurotoxicity in rat hippocampi. Four groups were examined: Control: Received 6 hours of 3 l/min gas (air and 30 % O2) and intraperitoneal saline. NAC: Received 6 hours of 3 l/min gas and 150 mg/kg NAC intraperitoneally. Sev: Exposed to 6 hours of 3 l/min gas and 3 % sevoflurane. Sev+NAC: Received 6 hours of 3 l/min gas, 3 % sevoflurane, and 150 mg/kg NAC. Protein levels of NRF-2, NLRP3, IL-1β, caspase-1, Beclin 1, p62, LC3A, and apoptosis markers were assessed. Sevoflurane and NAC alone reduced autophagy, while Sev+NAC group maintained autophagy levels. Sev group had elevated NRF-2, NLRP3, pNRF2, Caspase-1, and IL-1β, which were reduced in Sev+NAC. Apoptosis was higher in Sev, but Sev+NAC showed reduced apoptosis compared to the control. In summary, sevoflurane induced neurotoxicity in developing hippocampus, which was mitigated by N-acetylcysteine administration.

Oxidative Stress, Endothelial Dysfunction, and N-Acetylcysteine in Type 2 Diabetes Mellitus

Significance: Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality globally. Endothelial dysfunction is closely associated with the development and progression of CVDs. Patients with diabetes mellitus (DM) especially type 2 DM (T2DM) exhibit a significant endothelial cell (EC) dysfunction with substantially increased risk for CVDs. Recent Advances: Excessive reactive oxygen species (ROS) and oxidative stress are important contributing factors to EC dysfunction and subsequent CVDs. ROS production is significantly increased in DM and is critically involved in the development of endothelial dysfunction in diabetic patients. In this review, efforts are made to discuss the role of excessive ROS and oxidative stress in the pathogenesis of endothelial dysfunction and the mechanisms for excessive ROS production and oxidative stress in T2DM. Critical Issues: Although studies with diabetic animal models have shown that targeting ROS with traditional antioxidant vitamins C and E or other antioxidant supplements provides promising beneficial effects on endothelial function, the cardiovascular outcomes of clinical studies with these antioxidant supplements have been inconsistent in diabetic patients. Future Directions: Preclinical and limited clinical data suggest that N-acetylcysteine (NAC) treatment may improve endothelial function in diabetic patients. However, well-designed clinical studies are needed to determine if NAC supplementation would effectively preserve endothelial function and improve the clinical outcomes of diabetic patients with reduced cardiovascular morbidity and mortality. With better understanding on the mechanisms of ROS generation and ROS-mediated endothelial damages/dysfunction, it is anticipated that new selective ROS-modulating agents and effective personalized strategies will be developed for the management of endothelial dysfunction in DM.

Understanding the biofilm development of Acinetobacter baumannii and novel strategies to combat infection

Acinetobacter baumannii (A. baumannii) is a Gram-negative, nonmotile, and aerobic bacillus emerged as a superbug, due to increasing the possibility of infection and accelerating rates of antimicrobial agents. It is recognized as a nosocomial pathogen due to its ability to form biofilms. These biofilms serve as a defensive barrier, increase antibiotic resistance, and make treatment more difficult. As a result, the current situation necessitates the rapid emergence of novel therapeutic approaches to ensure successful treatment outcomes. This review explores the intricate relationship between biofilm formation and antibiotic resistance in A. baumannii, emphasizing the role of key virulence factors and quorum sensing (QS) mechanisms that will lead to infections and facilitate insight into developing innovative method to control A. baumannii infections. Furthermore, the review article looks into promising approaches for preventing biofilm formation on medically important surfaces and potential therapeutic methods for eliminating preformed biofilms, which can address biofilm-associated A. baumannii infections. Modern advances in emerging therapeutic options such as antimicrobial peptide (AMPs), nanoparticles (NPs), bacteriophage therapy, photodynamic therapy (PDT), and other biofilm inhibitors can assist readers understand the current landscape and future prospects for effectively treating A. baumannii biofilm infections.

Mitofilin in cardiovascular diseases: Insights into the pathogenesis and potential pharmacological interventions

The impact of mitochondrial dysfunction on the pathogenesis of cardiovascular disease is increasing. However, the precise underlying mechanism remains unclear. Mitochondria produce cellular energy through oxidative phosphorylation while regulating calcium homeostasis, cellular respiration, and the production of biosynthetic chemicals. Nevertheless, problems related to cardiac energy metabolism, defective mitochondrial proteins, mitophagy, and structural changes in mitochondrial membranes can cause cardiovascular diseases via mitochondrial dysfunction. Mitofilin is a critical inner mitochondrial membrane protein that maintains cristae structure and facilitates protein transport while linking the inner mitochondrial membrane, outer mitochondrial membrane, and mitochondrial DNA transcription. Researchers believe that mitofilin may be a therapeutic target for treating cardiovascular diseases, particularly cardiac mitochondrial dysfunctions. In this review, we highlight current findings regarding the role of mitofilin in the pathogenesis of cardiovascular diseases and potential therapeutic compounds targeting mitofilin.

N-acetylcysteine absorption and its potential dual effect improve fitness and fruit yield in Xylella fastidiosa infected plants

BACKGROUND

Xylella fastidiosa is a multi-host bacterium that can be detected in hundreds of plant species including several crops. Diseases caused by X. fastidiosa are considered a threat to global food production. The primary method for managing diseases caused by X. fastidiosa involves using insecticides to control the vector. Hence, it is necessary to adopt new and sustainable disease management technologies to control not only the insect but also the bacteria and plant health. We demonstrated that N-acetylcysteine (NAC), a low-cost cysteine analogue, is a sustainable molecule that can be used in agriculture to decrease the damage caused by X. fastidiosa and improve plant health.

RESULTS

Using 15N-NAC we proved that this analogue was absorbed by the roots and transported to different parts of the plant. Inside the plant, NAC reduced the bacterial population by 60-fold and the number of xylem vessels blocked by bacterial biofilms. This reflected in a recovery of 0.28-fold of the daily sap flow compared to health plants. In addition, NAC-treated citrus variegated chlorosis (CVC) plants decreased the oxidative stress by improving the activity of detoxifying enzymes. Moreover, the use of NAC in field conditions positively contributed to the increase in fruit yield of CVC-diseased plants.

CONCLUSION

Our research not only advances the understanding of NAC absorption in plants, but also indicates its dual effect as an antimicrobial and antioxidant molecule. This, in turn, negatively affects bacterial survival while improving plant health by decreasing oxidative stress. Overall, the positive field-based evidence supports the viability of NAC as a sustainable agricultural application. © 2024 Society of Chemical Industry.

N-Acetylcysteine Attenuates Sepsis-Induced Muscle Atrophy by Downregulating Endoplasmic Reticulum Stress

(1) Background: Sepsis-induced muscle atrophy is characterized by a loss of muscle mass and function which leads to decreased quality of life and worsens the long-term prognosis of patients. N-acetylcysteine (NAC) has powerful antioxidant and anti-inflammatory properties, and it relieves muscle wasting caused by several diseases, whereas its effect on sepsis-induced muscle atrophy has not been reported. The present study investigated the effect of NAC on sepsis-induced muscle atrophy and its possible mechanisms. (2) Methods: The effect of NAC on sepsis-induced muscle atrophy was assessed in vivo and in vitro using cecal ligation and puncture-operated (CLP) C57BL/6 mice and LPS-treated C2C12 myotubes. We used immunofluorescence staining to analyze changes in the cross-sectional area (CSA) of myofibers in mice and the myotube diameter of C2C12. Protein expressions were analyzed by Western blotting. (3) Results: In the septic mice, the atrophic response manifested as a reduction in skeletal muscle weight and myofiber cross-sectional area, which is mediated by muscle-specific ubiquitin ligases-muscle atrophy F-box (MAFbx)/Atrogin-1 and muscle ring finger 1 (MuRF1). NAC alleviated sepsis-induced skeletal muscle wasting and LPS-induced C2C12 myotube atrophy. Meanwhile, NAC inhibited the sepsis-induced activation of the endoplasmic reticulum (ER) stress signaling pathway. Furthermore, using 4-Phenylbutyric acid (4-PBA) to inhibit ER stress in LPS-treated C2C12 myotubes could partly abrogate the anti-muscle-atrophy effect of NAC. Finally, NAC alleviated myotube atrophy induced by the ER stress agonist Thapsigargin (Thap). (4) Conclusions: NAC can attenuate sepsis-induced muscle atrophy, which may be related to downregulating ER stress.

Acute rotenone poisoning: A scoping review

Context

Rotenone is a toxic chemical found in various plants, including some used as food. Rotenone poisoning can be fatal and there is no antidote. Mechanistically, rotenone inhibits mitochondrial complex I, leading to reduced ATP production, compensatory glycolytic upregulation and secondary lactate production, and oxidative stress. Our literature review examined acute rotenone poisoning in humans, including exposure scenarios, clinical presentations, and treatments.

Methods

We searched five databases for relevant literature from database inception through the search date: July 12, 2022, pairing controlled vocabulary and keywords for "rotenone" with terms relating to human exposures and outcomes, such as "ingestion," "exposure," and "poisoning." We included all peer-reviewed reports found using the search terms where the full English text was available. Data abstracted included the number, age, weight, and sex of the exposed person(s), country where exposure happened, exposure scenario, ingestion context, estimated dose, clinical features, whether hospitalization occurred, treatments, and outcomes.

Results

After removing non-qualifying sources from 2,631 publications, we identified 11 case reports describing 18 victims, 15 of whom were hospitalized and five died. Most cases occurred in private quarters where victims unknowingly consumed rotenone-containing plants. Vomiting and metabolic acidosis occurred most commonly. Some patients exhibited impaired cardiopulmonary function. Supportive treatment addressed symptoms and included gastric lavage and/or activated charcoal to remove rotenone from the stomach, vasopressors for hypotension, mechanical ventilation for respiratory insufficiency, and sodium bicarbonate for acidosis. Some patients received N-acetylcysteine to counter oxidative stress.

Conclusions

Rotenone poisoning, though rare, can be fatal. Exposure prevention is impractical since rotenone is found in some plants used as food or pesticides. Cases may be under-diagnosed because symptoms are non-specific and under-reported in English-language journals since most cases occurred in non-English speaking countries. Treatments are supportive. Exploring antioxidant therapy in animal models of rotenone poisoning may be indicated considering rotenone's mechanism of toxicity.

Clinical Management in Traumatic Brain Injury

Traumatic brain injury is one of the leading causes of morbidity and mortality worldwide and is one of the major public healthcare burdens in the US, with millions of patients suffering from the traumatic brain injury itself (approximately 1.6 million/year) or its repercussions (2-6 million patients with disabilities). The severity of traumatic brain injury can range from mild transient neurological dysfunction or impairment to severe profound disability that leaves patients completely non-functional. Indications for treatment differ based on the injury's severity, but one of the goals of early treatment is to prevent secondary brain injury. Hemodynamic stability, monitoring and treatment of intracranial pressure, maintenance of cerebral perfusion pressure, support of adequate oxygenation and ventilation, administration of hyperosmolar agents and/or sedatives, nutritional support, and seizure prophylaxis are the mainstays of medical treatment for severe traumatic brain injury. Surgical management options include decompressive craniectomy or cerebrospinal fluid drainage via the insertion of an external ventricular drain. Several emerging treatment modalities are being investigated, such as anti-excitotoxic agents, anti-ischemic and cerebral dysregulation agents, S100B protein, erythropoietin, endogenous neuroprotectors, anti-inflammatory agents, and stem cell and neuronal restoration agents, among others.

AI-assisted literature exploration of innovative Chinese medicine formulas

Objective: Our study provides an innovative approach to exploring herbal formulas that contribute to the promotion of sustainability and biodiversity conservation. We employ data mining, integrating keyword extraction, association rules, and LSTM-based generative models to analyze classical Traditional Chinese Medicine (TCM) texts. We systematically decode classical Chinese medical literature, conduct statistical analyses, and link these historical texts with modern pharmacogenomic references to explore potential alternatives. Methods: We present a novel iterative keyword extraction approach for discerning diverse herbs in historical TCM texts from the Pu-Ji Fang copies. Utilizing association rules, we uncover previously unexplored herb pairs. To bridge classical TCM herbal pairs with modern genetic relationships, we conduct gene-herb searches in PubMed and statistically validate this genetic literature as supporting evidence. We have expanded on the present work by developing a generative language model for suggesting innovative TCM formulations based on textual herb combinations. Results: We collected associations with 7,664 PubMed cross-search entries for gene-herb and 934 for Shenqifuzheng Injection as a positive control. We analyzed 16,384 keyword combinations from Pu-Ji Fang's 426 volumes, employing statistical methods to probe gene-herb associations, focusing on examining differences among the target genes and Pu-Ji Fang herbs. Conclusion: Analyzing Pu-Ji Fang reveals a historical focus on flavor over medicinal aspects in TCM. We extend our work on developing a generative model from classical textual keywords to rapidly produces novel herbal compositions or TCM formulations. This integrated approach enhances our comprehension of TCM by merging ancient text analysis, modern genetic research, and generative modeling.

N-Acetylcysteine Alleviates D-Galactose-Induced Injury of Ovarian Granulosa Cells in Female Rabbits by Regulating the PI3K/Akt/mTOR Signaling Pathway

The ovary plays a crucial role in the reproductive system of female animals. Ovarian problems such as ovarian insufficiency, premature aging, polycystic ovary syndrome, and ovarian cysts may lead to ovulation disorders, abnormal hormone secretion, or luteal dysfunction, thereby increasing the risk of infertility and abortion. Only when the ovarian function and other organs in the reproductive system remain healthy and work normally can female animals be ensured to carry out reproductive activities regularly, improve the pregnancy rate and litter size, promote the healthy development of the fetus, and then improve their economic value. The follicle, as the functional unit of the ovary, is composed of theca cells, granulosa cells (GCs), and oocytes. GCs are the largest cell population and main functional unit in follicles and provide the necessary nutrients for the growth and development of follicles. N-acetylcysteine (NAC) is a prevalent and cell-permeable antioxidant molecule that effectively prevents apoptosis and promotes cellular survival. Over the past few years, its function in boosting reproductive performance in animals at the cellular level has been widely acknowledged. However, its specific role and mechanism in influencing GCs is yet to be fully understood. The objective of this study was to examine the effects of NAC on ovarian damage in female rabbits. For this purpose, D-galactose (D-gal) was first used to establish a model of damaged GCs, with exposure to 1.5 mg/mL of D-gal leading to substantial damage. Subsequently, varying concentrations of NAC were introduced to determine the precise mechanism through which it influences cell damage. Based on the results of the Cell Counting Kit-8 assay, flow cytometry, and Western blotting, it was found that 0.5 mg/mL of NAC could significantly suppress cell apoptosis and promote proliferation. In particular, it decreased the expression levels of Bax, p53, and Caspase-9 genes, while concurrently upregulating the expression of the BCL-2 gene. Moreover, NAC was found to alleviate intracellular oxidative stress, suppress the discharge of mitochondrial Cytochrome c, and boost the enzymatic activities of CAT (Catalase), GSH (Glutathione), and SOD (Superoxide dismutase). RNA sequencing analysis subsequently underscored the critical role of the PI3K/Akt/mTOR pathway in governing proliferation and apoptosis within GCs. These findings demonstrated that NAC could significantly influence gene expression within this pathway, thereby clarifying the exact relationship between the PI3K/Akt/mTOR signaling cascade and the underlying cellular processes controlling proliferation and apoptosis. In conclusion, NAC can reduce the expression of Bax, p53, and Caspase-9 genes, inhibit the apoptosis of GCs, improve cell viability, and resist D-gal-induced oxidative stress by increasing the activity of CAT, GSH, and SOD. The molecular mechanism of NAC in alleviating D-gal-induced ovarian GC injury in female rabbits by regulating the PI3K/Akt/mTOR signaling pathway provides experimental evidence for the effect of NAC on animal reproductive function at the cellular level.

Enteral N-acetylcysteine to reduce serum cobalt concentrations secondary to prosthetic knee-associated metallosis: A case report

PURPOSE

Cobalt metallosis is a rare but dangerous complication of total joint arthroplasty resulting from deterioration of the joint leading to metal-on-metal friction and breakdown. Potential manifestations vary in severity and include dilated cardiomyopathy, thyroid dysfunction, cognitive disturbances, neuropathy, fatigue, and weakness. The therapeutic role of N-acetylcysteine in metallosis has been investigated due to its ability to chelate with heavy metal ions, such as cobalt and chromium.

SUMMARY

Here we report the case of a 71-year-old female who presented with suspected metallosis diagnosed in the outpatient setting due to symptoms of significant weight loss and failure to thrive. This metallosis was secondary to the hardware breakdown of a left knee revision roughly 6 years previously. The patient was not a surgical candidate due to her poor nutrition status and was started on nasojejunal tube feeds along with N-acetylcysteine 600 mg by mouth twice daily for 45 days. The patient's serum cobalt levels decreased from 61.7 µg/L on admission to 16.2 µg/L prior to her undergoing proper revision of the left knee roughly 2 months after admission to the hospital. The patient tolerated treatment well and was able to be discharged the day after surgery, with no further complaints or complications.

CONCLUSION

This case report contributes to the body of literature suggesting that administration of N-acetylcysteine can reduce serum cobalt concentrations, without notable adverse effects, in the context of prosthetic knee-associated metallosis.

Ferroptosis and oxidative stress in endometriosis: A systematic review of the literature

BACKGROUND

Endometriosis (EMT) a common gynecological condition in women, an inflammatory disease characterized by the presence of endometrial tissue on organs and tissues in the pelvis, and is mainly associated with chronic pelvic pain and infertility. As the etiology has not been fully elucidated, current treatment is limited to surgery, hormones and painkillers, with more side effects and difficulty in achieving long-term relief. Oxidative stress manifests itself as an overproduction of reactive oxygen species, which has an integral impact in the pathology of female reproductive disorders. In this review, we evaluate the mechanisms of iron overload-induced oxidative stress and ferroptosis in EMT and their pathophysiological implications.

METHODS

Because the etiology has not been fully elucidated, current treatments are limited to surgery, hormones, and painkillers, which have many side effects and are difficult to achieve long-term relief.

RESULTS

We interpreted that antioxidants as well as ferroptosis inducers show promising results in the treatment of EMT, but their application in this population needs to be further investigated.

CONCLUSION

In combination with the interpretation of previous studies, it was shown that iron overload is present in the peritoneal fluid, endometriotic lesions, peritoneum and macrophages in the abdominal cavity. However, the programmed cellular ferroptosis associated with iron overload is resisted by endometriotic foci, which is critical to the pathophysiology of EMT with local iron overload and inflammation.

N-Acetylcysteine Alters Disease Progression and Increases Janus Kinase Mutation Frequency in a Mouse Model of Precursor B-Cell Acute Lymphoblastic Leukemia

B-cell acute lymphoblastic leukemia (B-ALL) is the most prevalent type of cancer in young children and is associated with high levels of reactive oxygen species (ROS). The antioxidant N-acetylcysteine (NAC) was tested for its ability to alter disease progression in a mouse model of B-ALL. Mb1-CreΔPB mice have deletions in genes encoding PU.1 and Spi-B in B cells and develop B-ALL at 100% incidence. Treatment of Mb1-CreΔPB mice with NAC in drinking water significantly reduced the frequency of CD19+ pre-B-ALL cells infiltrating the thymus at 11 weeks of age. However, treatment with NAC did not reduce leukemia progression or increase survival by a median 16 weeks of age. NAC significantly altered gene expression in leukemias in treated mice. Mice treated with NAC had increased frequencies of activating mutations in genes encoding Janus kinases 1 and 3. In particular, frequencies of Jak3 R653H mutations were increased in mice treated with NAC compared with control drinking water. NAC opposed oxidization of PTEN protein ROS in cultured leukemia cells. These results show that NAC alters leukemia progression in this mouse model, ultimately selecting for leukemias with high Jak3 R653H mutation frequencies. SIGNIFICANCE STATEMENT: In a mouse model of precursor B-cell acute lymphoblastic leukemia associated with high levels of reactive oxygen species, treatment with N-acetylcysteine did not delay disease progression but instead selected for leukemic clones with activating R653H mutations in Janus kinase 3.

The Combined Antioxidant Effects of N-Acetylcysteine, Vitamin D3, and Glutathione from the Intestinal-Neuronal In Vitro Model

Chronic oxidative stress has been consistently linked to age-related diseases, conditions, and degenerative syndromes. Specifically, the brain is the organ that significantly contributes to declining quality of life in ageing. Since the body cannot completely counteract the detrimental effects of oxidative stress, nutraceuticals' antioxidant properties have received significant attention in recent years. This study assesses the potential health benefits of a novel combination of glutathione, vitamin D3, and N-acetylcysteine. To examine the combination's absorption and biodistribution and confirm that it has no harmful effects, the bioavailability of the mixture was first evaluated in a 3D model that mimicked the intestinal barrier. Further analyses on the blood-brain barrier was conducted to determine the antioxidant effects of the combination in the nervous system. The results show that the combination reaches the target and successfully crosses the blood-brain and intestinal barriers, demonstrating enhanced advantages on the neurological system, such as a reduction (about 10.5%) in inflammation and enhancement in cell myelination (about 20.4%) and brain tropism (about 18.1%) compared to the control. The results support the cooperative effect of N-acetylcysteine, vitamin D3, and glutathione to achieve multiple health benefits, outlining the possibility of an alternative nutraceutical approach.

N-Acetyl Cysteine Prevents Arterial Thrombosis in a Dose-Dependent Manner In Vitro and in Mice

BACKGROUND

Platelet-rich thrombi occlude arteries causing fatal infarcts like heart attacks and strokes. Prevention of thrombi by current antiplatelet agents can cause major bleeding. Instead, we propose using N-acetyl cysteine (NAC) to act against the protein VWF (von Willebrand factor), and not platelets, to prevent arterial thrombi from forming.

METHODS

NAC was assessed for its ability to prevent arterial thrombosis by measuring platelet accumulation rate and occlusion time using a microfluidic model of arterial thrombosis with human blood. Acute clot formation, clot stability, and tail bleeding were measured in vivo with the murine modified Folts model. The effect of NAC in the murine model after 6 hours was also measured to determine any persistent effects of NAC after it has been cleared from the blood.

RESULTS

We demonstrate reduction of thrombi formation following treatment with NAC in vitro and in vivo. Human whole blood treated with 3 or 5 mmol/L NAC showed delayed thrombus formation 2.0× and 3.7× longer than control, respectively (P<0.001). Blood treated with 10 mmol/L NAC did not form an occlusive clot, and no macroscopic platelet aggregation was visible (P<0.001). In vivo, a 400-mg/kg dose of NAC prevented occlusive clots from forming in mice without significantly affecting tail bleeding times. A lower dose of NAC significantly reduced clot stability. Mice given multiple injections showed that NAC has a lasting and cumulative effect on clot stability, even after being cleared from the blood (P<0.001).

CONCLUSIONS

Both preclinical models demonstrate that NAC prevents thrombus formation in a dose-dependent manner without significantly affecting bleeding time. This work highlights a new pathway for preventing arterial thrombosis, different from antiplatelet agents, using an amino acid derivative as an antithrombotic therapeutic.

Distinguishing Molecular Mechanical Action from Photothermal and Photodynamic Behavior

Molecular motors (MM) are molecular machines, or nanomachines, that rotate unidirectionally upon photostimulation and perform mechanical work on their environment. In the last several years, it has been shown that the photomechanical action of MM can be used to permeabilize lipid bilayers, thereby killing cancer cells and pathogenic microorganisms and controlling cell signaling. The work contributes to a growing acknowledgement that the molecular actuation characteristic of these systems is useful for various applications in biology. However, the mechanical effects of molecular motion on biological materials are difficult to disentangle from photodynamic and photothermal action, which are also present when a light-absorbing fluorophore is irradiated with light. Here, an overview of the key methods used by various research groups to distinguish the effects of photomechanical, photodynamic, and photothermal action is provided. It is anticipated that this discussion will be helpful to the community seeking to use MM to develop new and distinctive medical technologies that result from mechanical disruption of biological materials.

Akt Signaling and Nitric Oxide Synthase as Possible Mediators of the Protective Effect of N-acetyl-L-cysteine in Prediabetes Induced by Sucrose

The aim of this work was to evaluate possible mechanisms involved in the protective effect of N-acetyl-L-cysteine (NAC) on hepatic endocrine-metabolic, oxidative stress, and inflammatory changes in prediabetic rats. For that, normal male Wistar rats (60 days old) were fed for 21 days with 10% sucrose in their drinking water and 5 days of NAC administration (50 mg/kg, i.p.) and thereafter, we determined: serum glucose, insulin, transaminases, uric acid, and triglyceride levels; hepatic fructokinase and glucokinase activities, glycogen content, lipogenic gene expression; enzymatic and non-enzymatic oxidative stress, insulin signaling pathway, and inflammatory markers. Results showed that alterations evinced in sucrose-fed rats (hypertriglyceridemia, hyperinsulinemia, and high liver fructokinase activity together with increased liver lipogenic gene expression and oxidative stress and inflammatory markers) were prevented by NAC administration. P-endothelial nitric oxide synthase (P-eNOS)/eNOS and pAKT/AKT ratios, decreased by sucrose ingestion, were restored after NAC treatment. In conclusion, the results suggest that NAC administration improves glucose homeostasis, oxidative stress, and inflammation in prediabetic rats probably mediated by modulation of the AKT/NOS pathway. Administration of NAC may be an effective complementary strategy to alleviate or prevent oxidative stress and inflammatory responses observed in type 2 diabetes at early stages of its development (prediabetes).

Effect of N-Acetylcysteine on Cisplatin Toxicity: A Review of the Literature

N-acetylcysteine (NAC) is a membrane-permeable cysteine precursor capable of enhancing the intracellular cysteine pool, enhancing cellular glutathione (GSH) synthesis, and thus potentiating the endogenous antioxidant mechanism. Late administration of NAC after cisplatin has been shown in different in vivo studies to reduce the side effects caused by various toxicities at different levels without affecting the antitumor efficacy of platinum, improving total and enzymatic antioxidant capacity and decreasing oxidative stress markers. These characteristics provide NAC with a rationale as a potentially effective chemo protectant in cisplatin-based therapeutic cycles. NAC represents a potential candidate as a chemoprotective agent to decrease toxicities secondary to cisplatin treatment. It suggests that it could be used in clinical trials, whereby the effective dose, timing, and route should be adjusted to optimize chemoprotection. This review provides an overview of the effect of NAC on cisplatin toxicity, a drug widely used in the clinic in adults and children.

Unlocking the link: how hippocampal glutathione-glutamate coupling predicts cognitive impairment in multiple sclerosis patients

Cognitive impairment is a common symptom of multiple sclerosis and profoundly impacts quality of life. Glutathione (GSH) and glutamate (Glu) are tightly linked in the brain, participating in cognitive function. However, GSH-Glu couplings in cognitive brain regions and their relationship with cognitive impairment in relapsing-remitting multiple sclerosis (RRMS) remains unclear. Forty-one RRMS patients and 43 healthy controls underwent magnetic resonance spectroscopy to measure GSH and Glu levels in the posterior cingulate cortex, medial prefrontal cortex and left hippocampus. Neuropsychological tests were used to evaluate the cognitive function. The Glu/GSH ratio was used to indicate the coupling between GSH and Glu and was tested as a predictor of cognitive performance. The results show that RRMS patients exhibited reduced hippocampal GSH and Glu levels, which were found to be significant predictors of worse verbal and visuospatial memory, respectively. Moreover, GSH levels were dissociated from Glu levels in the left hippocampus of RRMS patients. Hippocampal Glu/GSH ratio is significantly correlated with processing speed and has a greater predictive effect. Here we show the hippocampal Glu/GSH ratio could serve as a new potential marker for characterizing cognitive impairment in RRMS, providing a new direction for clinical detection of cognitive impairment.

Gastropod Slime-Based Gel as an Adjustable Synthetic Model for Human Airway Mucus

Airway mucus works as a protective barrier in the human body, as it entraps pathogens that will be later cleared from the airways by ciliary transport or by coughing, thus featuring the rheological properties of a highly stretchable gel. Nonetheless, the study of these physical barrier as well as transport properties remains limited due to the restricted and invasive access to lungs and bronchi to retrieve mucus and to the poor repeatability inherent to native mucus samples. To overcome these limits, we report on a biobased synthetic mucus prepared from snail slime and multibranched thiol cross-linker, which are able to establish disulfide bonds, in analogy with the disulfide bonding of mucins, and therefore build viscoelastoplastic hydrogels. The gel macroscopic properties are tuned by modifying the cross-linker and slime concentrations and can quantitatively match those of native sputum from donors with cystic fibrosis (CF) or non-cystic fibrosis bronchiectasis (NCFB) both in the small- and large-deformation regimes. Heterogeneous regimes were locally found in the mucus model by passive microrheology, in which both diffusive and non-diffusive motion are present, similar to what is observed in sputa. The biobased synthetic approach proposed in the present study thus allows to produce, with commercially available components, a promising model to native respiratory mucus regarding both mechanical and, to a lesser extent, physicochemical aspects.

Oxidative stress and antioxidants in cataract development

PURPOSE OF REVIEW

Oxidative stress plays a central role in cataract pathogenesis, a leading cause of global blindness. This review delves into the role of oxidative stress in cataract development and key biomarkers - glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), and 4-hydroxynonenal (4-HNE) - to clarify their functions and potential applications in predictive diagnostics and therapies.

RECENT FINDINGS

Antioxidants serve as pivotal markers in cataract pathogenesis. GSH affects the central lens due to factors such as enzyme depletion and altered connexin expression, impairing GSH diffusion. Age-related oxidative stress may hinder GSH transport via connexin channels or an internal microcirculation system. N-acetylcysteine, a GSH precursor, shows promise in mitigating lens opacity when applied topically. Additionally, SOD, particularly SOD1, correlates with increased cataract development and gel formulations have exhibited protective effects against posterior subscapular cataracts. Lastly, markers of lipid peroxidation, MDA and 4-HNE, have been shown to reflect disease severity. Studies suggest a potential link between 4-HNE and connexin channel modification, possibly contributing to reduced GSH levels.

SUMMARY

Oxidative stress is a significant contributor to cataract development, underscoring the importance of antioxidants in diagnosis and treatment. Notably, GSH depletion, SOD decline, and lipid peroxidation markers are pivotal factors in cataract pathogenesis, offering promising avenues for both diagnosis and therapeutic intervention.

N-Acetylcysteine and Atherosclerosis: Promises and Challenges

Atherosclerosis remains a leading cause of cardiovascular diseases. Although the mechanism for atherosclerosis is complex and has not been fully understood, inflammation and oxidative stress play a critical role in the development and progression of atherosclerosis. N-acetylcysteine (NAC) has been used as a mucolytic agent and an antidote for acetaminophen overdose with a well-established safety profile. NAC has antioxidant and anti-inflammatory effects through multiple mechanisms, including an increase in the intracellular glutathione level and an attenuation of the nuclear factor kappa-B mediated production of inflammatory cytokines like tumor necrosis factor-alpha and interleukins. Numerous animal studies have demonstrated that NAC significantly decreases the development and progression of atherosclerosis. However, the data on the outcomes of clinical studies in patients with atherosclerosis have been limited and inconsistent. The purpose of this review is to summarize the data on the effect of NAC on atherosclerosis from both pre-clinical and clinical studies and discuss the potential mechanisms of action of NAC on atherosclerosis, as well as challenges in the field.

N-acetyl-L-cysteine improves the performance of chronic cyclic heat-stressed finisher broilers but has no effect on tissue glutathione levels

1. It was hypothesised that dietary N-acetyl-L-cysteine (NAC) in feed, as a source of cysteine, could improve the performance of heat-stressed finisher broilers by fostering glutathione (GSH) synthesis. GSH is the most abundant intracellular antioxidant for which the sulphur amino acid cysteine is rate limiting for its synthesis.2. In the first experiment, four levels of NAC: 0, 500, 1000 and 2000 mg/kg were added to a diet with a suboptimal level of sulphur amino acids in the finisher phase. In the second experiment, NAC was compared to other sulphur amino acid sources at equal molar amounts of digestible sulphur amino acids. Birds were allocated to four groups: control, 2000 mg/kg NAC, 1479 mg/kg L-cystine, and 2168 mg/kg Ca-salt of 2-hydroxy-4-(methylthio)butanoic acid. A chronic cyclic heat stress model (temperature was increased to 34°C for 7 h daily) was initiated at 28 d of age.3. In the first experiment, growth performance and feed efficiency in the finisher phase were significantly improved by graded NAC. ADG was 88.9, 92.2, 93.7 and 97.7 g/d, and the feed-to-gain ratio was 2.18, 1.91, 1.85 and 1.81 for the 0, 500, 1000 and 2000 mg/kg NAC treatments, respectively. However, liver and heart GSH levels were not affected by NAC. On d 29, liver gene transcript of cystathionine-beta-synthase like was reduced by NAC, which suggested reduced trans-sulphuration activity. The second experiment showed that L-cystine and Ca-salt of 2-hydroxy-4-(methylthio) butanoic acid were more effective in improving performance than NAC.4. In conclusion, N-acetyl-L-cysteine improved dose-dependently growth and feed efficiency in heat-stressed finishing broilers. However, this was not associated with changes in tissue GSH levels, but more likely worked by sparing methionine and/or NAC's and cysteine's direct antioxidant properties.

Modulation of Kynurenic Acid Production by N-acetylcysteine Prevents Cognitive Impairment in Adulthood Induced by Lead Exposure during Lactation in Mice

Lead (Pb2+) exposure during early life induces cognitive impairment, which was recently associated with an increase in brain kynurenic acid (KYNA), an antagonist of NMDA and alpha-7 nicotinic receptors. It has been described that N-acetylcysteine (NAC) favors an antioxidant environment and inhibits kynurenine aminotransferase II activity (KAT II, the main enzyme of KYNA production), leading to brain KYNA levels decrease and cognitive improvement. This study aimed to investigate whether the NAC modulation of the brain KYNA levels in mice ameliorated Pb2+-induced cognitive impairment. The dams were divided into four groups: Control, Pb2+, NAC, and Pb2++NAC, which were given drinking water or 500 ppm lead acetate in the drinking water ad libitum, from 0 to 23 postnatal days (PNDs). The NAC and Pb2++NAC groups were simultaneously fed NAC (350 mg/day) in their chow from 0 to 23 PNDs. At PND 60, the effect of the treatment with Pb2+ and in combination with NAC on learning and memory performance was evaluated. Immediately after behavioral evaluation, brain tissues were collected to assess the redox environment; KYNA and glutamate levels; and KAT II activity. The NAC treatment prevented the long-term memory deficit exhibited in the Pb2+ group. As expected, Pb2+ group showed redox environment alterations, fluctuations in glutamate levels, and an increase in KYNA levels, which were partially avoided by NAC co-administration. These results confirmed that the excessive KYNA levels induced by Pb2+ were involved in the onset of cognitive impairment and could be successfully prevented by NAC treatment. NAC could be a tool for testing in scenarios in which KYNA levels are associated with the induction of cognitive impairment.

Reactive Oxygen Species and Strategies for Antioxidant Intervention in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a life-threatening pulmonary condition characterized by the sudden onset of respiratory failure, pulmonary edema, dysfunction of endothelial and epithelial barriers, and the activation of inflammatory cascades. Despite the increasing number of deaths attributed to ARDS, a comprehensive therapeutic approach for managing patients with ARDS remains elusive. To elucidate the pathological mechanisms underlying ARDS, numerous studies have employed various preclinical models, often utilizing lipopolysaccharide as the ARDS inducer. Accumulating evidence emphasizes the pivotal role of reactive oxygen species (ROS) in the pathophysiology of ARDS. Both preclinical and clinical investigations have asserted the potential of antioxidants in ameliorating ARDS. This review focuses on various sources of ROS, including NADPH oxidase, uncoupled endothelial nitric oxide synthase, cytochrome P450, and xanthine oxidase, and provides a comprehensive overview of their roles in ARDS. Additionally, we discuss the potential of using antioxidants as a strategy for treating ARDS.

N-acetyl cysteine mitigates lung damage and inflammation after chlorine exposure in vivo and ex vivo

The objective of this study was to explore the effects of antioxidant treatments, specifically N-acetylcysteine (NAC) and N-acetylcysteine amide (NACA), in a mouse model of chlorine (Cl2)-induced lung injury. Additionally, the study aimed to investigate the utility of pig precision-cut lung slices (PCLS) as an ex vivo alternative for studying the short-term effects of Cl2 exposure and evaluating antioxidant treatments. The toxicological responses were analyzed in Cl2-exposed mice (inflammation, airway hyperresponsiveness (AHR)) and PCLS (viability, cytotoxicity, inflammatory mediators). Airways contractions were assessed using a small ventilator for mice and electric-field stimulation (EFS) for PCLS. Antioxidant treatments were administered to evaluate their effects. In Cl2-exposed mice, NAC treatment did not alleviate AHR, but it did reduce the number of neutrophils in bronchoalveolar lavage fluid and inflammatory mediators in lung tissue. In PCLS, exposure to Cl2 resulted in concentration-dependent toxicity, impairing the lung tissue's ability to respond to EFS-stimulation. NAC treatment increased viability, mitigated the toxic responses caused by Cl2 exposure, and maintained contractility comparable to unexposed controls. Interestingly, NACA did not provide any additional treatment effect beyond NAC in both models. In conclusion, the establishment of a pig model for Cl2-induced lung damage supports further investigation of NAC as a potential treatment. However, the lack of protective effects on AHR after NAC treatment in mice suggests that NAC alone may not be sufficient as a complete treatment for Cl2 injuries. Optimization of existing medications with a polypharmacy approach may be more successful in addressing the complex sequelae of Cl2-induced lung injury.

The influence of redox modulation on hypoxic endothelial cell metabolic and proteomic profiles through a small thiol-based compound tuning glutathione and thioredoxin systems

Reduction in oxygen levels is a key feature in the physiology of the bone marrow (BM) niche where hematopoiesis occurs. The BM niche is a highly vascularized tissue and endothelial cells (ECs) support and regulate blood cell formation from hematopoietic stem cells (HSCs). While in vivo studies are limited, ECs when cultured in vitro at low O2 (<5%), fail to support functional HSC maintenance due to oxidative environment. Therefore, changes in EC redox status induced by antioxidant molecules may lead to alterations in the cellular response to hypoxia likely favoring HSC self-renewal. To evaluate the impact of redox regulation, HUVEC, exposed for 1, 6, and 24 h to 3% O2 were treated with N-(N-acetyl-l-cysteinyl)-S-acetylcysteamine (I-152). Metabolomic analyses revealed that I-152 increased glutathione levels and influenced the metabolic profiles interconnected with the glutathione system and the redox couples NAD(P)+/NAD(P)H. mRNA analysis showed a lowered gene expression of HIF-1α and VEGF following I-152 treatment whereas TRX1 and 2 were stimulated. Accordingly, the proteomic study revealed the redox-dependent upregulation of thioredoxin and peroxiredoxins that, together with the glutathione system, are the main regulators of intracellular ROS. Indeed, a time-dependent ROS production under hypoxia and a quenching effect of the molecule were evidenced. At the secretome level, the molecule downregulated IL-6, MCP-1, and PDGF-bb. These results suggest that redox modulation by I-152 reduces oxidative stress and ROS level in hypoxic ECs and may be a strategy to fine-tune the environment of an in vitro BM niche able to support functional HSC maintenance.

Targeting biophysical microenvironment for improved treatment of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is responsible for high disability rates, high death rates, and significant cost to health systems. Growing evidence in recent decades shows significant biophysical microenvironment changes in COPD, impacting lung tissues, cells, and treatment response. Furthermore, such biophysical changes have shown great potential as novel targets for improved therapeutic strategy of COPD, where both pharmacological and non-pharmacological therapies focusing on repairing the biophysical microenvironment of the lung have emerged. We present the first comprehensive review of four distinct biophysical hallmarks [i.e., extracellular matrix (ECM) microarchitecture, stiffness, fluid shear stress, and mechanical stretch] in COPD, the possible involvement of pathological changes, possible effects, and correlated in vitro models and sum up the emerging COPD treatments targeting these biophysical hallmarks.

Schizophrenia and Glutathione: A Challenging Story

Schizophrenia (SZ) is a devastating mental illness with a complex and heterogeneous clinical state. Several conditions like symptoms, stage and severity of the disease are only some of the variables that have to be considered to define the disorder and its phenotypes. SZ pathophysiology is still unclear, and the diagnosis is currently relegated to the analysis of clinical symptoms; therefore, the search for biomarkers with diagnostic relevance is a major challenge in the field, especially in the era of personalized medicine. Though the mechanisms implicated in SZ are not fully understood, some processes are beginning to be elucidated. Oxidative stress, and in particular glutathione (GSH) dysregulation, has been demonstrated to play a crucial role in SZ pathophysiology. In fact, glutathione is a leading actor of oxidative-stress-mediated damage in SZ and appears to reflect the heterogeneity of the disease. The literature reports differing results regarding the levels of glutathione in SZ patients. However, each GSH state may be a sign of specific symptoms or groups of symptoms, candidating glutathione as a biomarker useful for discriminating SZ phenotypes. Here, we summarize the literature about the levels of glutathione in SZ and analyze the role of this molecule and its potential use as a biomarker.

Biochemical Changes in Cardiopulmonary Bypass in Cardiac Surgery: New Insights

Patients undergoing coronary revascularization with extracorporeal circulation or cardiopulmonary bypass (CPB) may develop several biochemical changes in the microcirculation that lead to a systemic inflammatory response. Surgical incision, post-CPB reperfusion injury and blood contact with non-endothelial membranes can activate inflammatory signaling pathways that lead to the production and activation of inflammatory cells, with cytokine production and oxidative stress. This inflammatory storm can cause damage to vital organs, especially the heart, and thus lead to complications in the postoperative period. In addition to the organic pathophysiology during and after the period of exposure to extracorporeal circulation, this review addresses new perspectives for intraoperative treatment and management that may lead to a reduction in this inflammatory storm and thereby improve the prognosis and possibly reduce the mortality of these patients.

N-Acetylcysteine and Its Immunomodulatory Properties in Humans and Domesticated Animals

N-acetylcysteine (NAC), an acetylated derivative of the amino acid L-cysteine, has been widely used as a mucolytic agent and antidote for acetaminophen overdose since the 1960s and the 1980s, respectively. NAC possesses antioxidant, cytoprotective, anti-inflammatory, antimicrobial, and mucolytic properties, making it a promising therapeutic agent for a wide range of diseases in both humans and domesticated animals. Oxidative stress and inflammation play a major role in the onset and progression of all these diseases. NAC's primary role is to replenish glutathione (GSH) stores, the master antioxidant in all tissues; however, it can also reduce levels of pro-inflammatory tumor necrosis factor-alpha (TNF-∝) and interleukins (IL-6 and IL-1β), inhibit the formation of microbial biofilms and destroy biofilms, and break down disulfide bonds between mucin molecules. Many experimental studies have been conducted on the use of NAC to address a wide range of pathological conditions; however, its effectiveness in clinical trials remains limited and studies often have conflicting results. The purpose of this review is to provide a concise overview of promising NAC usages for the treatment of different human and domestic animal disorders.

N-Acetylcysteine and Probenecid Adjuvant Therapy for Traumatic Brain Injury

N-Acetylcysteine (NAC) has shown promise as a putative neurotherapeutic for traumatic brain injury (TBI). Yet, many such promising compounds have limited ability to cross the blood-brain barrier (BBB), achieve therapeutic concentrations in brain, demonstrate target engagement, among other things, that have hampered successful translation. A pharmacologic strategy for overcoming poor BBB permeability and/or efflux out of the brain of organic acid-based, small molecule therapeutics such as NAC is co-administration with a targeted or nonselective membrane transporter inhibitor. Probenecid is a classic ATP-binding cassette and solute carrier inhibitor that blocks transport of organic acids, including NAC. Accordingly, combination therapy using probenecid as an adjuvant with NAC represents a logical neurotherapeutic strategy for treatment of TBI (and other CNS diseases). We have completed a proof-of-concept pilot study using this drug combination in children with severe TBI-the Pro-NAC Trial (ClinicalTrials.gov NCT01322009). In this review, we will discuss the background and rationale for combination therapy with probenecid and NAC in TBI, providing justification for further clinical investigation.

N-Acetylcysteine Displaces Glutathionyl-Moieties from Hg2+ and MeHg+ to Form More Hydrophobic Complexes at Near-Physiological Conditions

The anthropogenic release of Hg is associated with an increased human exposure risk. Since Hg2+ and MeHg+ have a high affinity for thiols, their interaction with L-glutathione (GSH) within mammalian cells is fundamentally involved in their toxicological chemistry and excretion. To gain insight into the interaction of these mercurials with multiple small molecular weight thiols, we have investigated their competitive interactions with GSH and N-acetylcysteine (NAC) at near-physiological conditions, using a liquid chromatographic approach. This approach involved the injection of each mercurial onto a reversed-phase (RP)-HPLC column (37 °C) using a PBS buffer mobile phase containing 5.0 mM GSH to simulate cytosolic conditions with Hg being detected in the column effluent by an inductively coupled plasma atomic emission spectrometer (ICP-AES). When the 5.0 mM GSH mobile phase was amended with up to 10 mM NAC, gradually increasing retention times of both mercurials were observed. To explain this behavior, the experiment with 5.0 mM NAC and 5.0 mM GSH was replicated using 50 mM Tris buffer (pH 7.4), and the Hg-containing fractions were analyzed by electrospray ionization mass spectrometry. The results revealed the presence of Hg(GS)(NAC) and Hg(NAC)2 for Hg2+ and MeHg(GS) and MeHg(NAC) for MeHg+, which suggests that the coordination/displacement of GS-moieties from each mercurial by the more hydrophobic NAC can explain their retention behavior. Since the biotransformations of both mercurials were observed at near-physiological conditions, they are of toxicological relevance as they provide a biomolecular explanation for some results that were obtained when animals were administered with each mercurial and NAC.

Advances in the Use of N-Acetylcysteine in Chronic Respiratory Diseases

N-acetylcysteine (NAC) is widely used because of its mucolytic effects, taking part in the therapeutic protocols of cystic fibrosis. NAC is also administered as an antidote in acetaminophen (paracetamol) overdosing. Thanks to its wide antioxidative and anti-inflammatory effects, NAC may also be of benefit in other chronic inflammatory and fibrotizing respiratory diseases, such as chronic obstructive pulmonary disease, bronchial asthma, idiopathic lung fibrosis, or lung silicosis. In addition, NAC exerts low toxicity and rare adverse effects even in combination with other treatments, and it is cheap and easily accessible. This article brings a review of information on the mechanisms of inflammation and oxidative stress in selected chronic respiratory diseases and discusses the use of NAC in these disorders.

N-Acetylcysteine amide (NACA) and diNACA inhibit H2O2-induced cataract formation ex vivo in pig and rat lenses

Oxidative stress plays a central role in cataract formation suggesting that antioxidants might slow cataract progression. The anticataract activity of N-acetylcysteine amide (NACA) and (2 R, 2 R')-3,3'-disulfanediyl bis(2-acetamidopropanamide) (diNACA) and/or N-acetylcysteine (NAC), were evaluated in porcine and rat lens models. Cataractogenesis via oxidation was induced with H2O2 and/or glucose oxidase (GO). Porcine lenses were incubated in 0.1 mM, 1 mM, or 10 mM NAC, NACA or diNACA for 24 h. Lenses were then transferred to media containing 0.75 mM H2O2 and 4.63U of GO in order to maintain a constant H2O2 level for an additional 8 h. At the end of incubation, lenses were imaged under darkfield microscopy. Separately, rat lenses were extracted from 3-week-old Wistar rats and incubated with either 10 mM NACA or 10 mM diNACA for 24 h prior to treatment with 0.2U GO to generate a steady source of ∼0.6 mM H2O2. Rat lenses were analyzed by LC-MS/MS to quantify changes in cysteine, cystine, glutathione (GSH) or oxidised glutathione (GSSG) levels in the lens epithelium, cortex or core. Pre-treatment with NACA or diNACA followed by oxidation with H2O2 and/or GO to stimulate cataract formation afforded rapid assessment in ex vivo porcine (32 h) and rat (48 h) lens models. Pre-treatment of isolated porcine lenses with 0.1 mM, 1 mM or 10 mM of either NAC, NACA or diNACA followed by H2O2/GO treatment resulted in reduced lens opacity relative to the lenses exposed to H2O2/GO, with NACA and diNACA reducing opacities to a greater extent than NAC. Rat lenses incubated with 10 mM NACA or 10 mM diNACA without exposure to H2O2 showed no signs of opacities. Pre-treatment of rat lenses with 10 mM NACA or 10 mM diNACA, followed by GO cataract induction resulted in reduced opacities compared to control (GO alone). LC-MS/MS analyses revealed that NACA, but not diNACA, increased cysteine, cystine and GSH levels in rat lens epithelium and cortex regions. Taken together, both NACA and diNACA inhibited cataract formation to a greater extent than NAC (all at 1-10 mM) in an ex vivo porcine lens model. Both NACA and diNACA (both at 10 mM) reduced cataract formation in rat lenses. Based on LC-MS/MS analyses, NACA-induced reduction in opacity observed in rat lenses was attributed to enhanced cysteine and GSH levels while the diNACA-induced reduction in opacity induced did not consistently increase cysteine, cystine and GSH levels and, therefore, appears to involve a different antioxidant mechanism. These screening studies warrant further testing of NACA and diNACA as anticataract agents.

Antibacterial activity of menadione alone and in combination with oxacillin against methicillin-resistant Staphylococcus aureus and its impact on biofilms

Introduction. Antibiotic resistance is a major threat to public health, particularly with methicillin-resistant Staphylococcus aureus (MRSA) being a leading cause of antimicrobial resistance. To combat this problem, drug repurposing offers a promising solution for the discovery of new antibacterial agents.Hypothesis. Menadione exhibits antibacterial activity against methicillin-sensitive and methicillin-resistant S. aureus strains, both alone and in combination with oxacillin. Its primary mechanism of action involves inducing oxidative stress.Methodology. Sensitivity assays were performed using broth microdilution. The interaction between menadione, oxacillin, and antioxidants was assessed using checkerboard technique. Mechanism of action was evaluated using flow cytometry, fluorescence microscopy, and in silico analysis.Aim. The aim of this study was to evaluate the in vitro antibacterial potential of menadione against planktonic and biofilm forms of methicillin-sensitive and resistant S. aureus strains. It also examined its role as a modulator of oxacillin activity and investigated the mechanism of action involved in its activity.Results. Menadione showed antibacterial activity against planktonic cells at concentrations ranging from 2 to 32 µg ml-1, with bacteriostatic action. When combined with oxacillin, it exhibited an additive and synergistic effect against the tested strains. Menadione also demonstrated antibiofilm activity at subinhibitory concentrations and effectively combated biofilms with reduced sensitivity to oxacillin alone. Its mechanism of action involves the production of reactive oxygen species (ROS) and DNA damage. It also showed interactions with important targets, such as DNA gyrase and dehydroesqualene synthase. The presence of ascorbic acid reversed its effects.Conclusion. Menadione exhibited antibacterial and antibiofilm activity against MRSA strains, suggesting its potential as an adjunct in the treatment of S. aureus infections. The main mechanism of action involves the production of ROS, which subsequently leads to DNA damage. Additionally, the activity of menadione can be complemented by its interaction with important virulence targets.

Effects of N-acetylcysteine on oxidative stress biomarkers, depression, and anxiety symptoms in patients with multiple sclerosis

AIM

N-acetylcysteine (NAC), a thiol-containing antioxidant and glutathione (GSH) precursor, attenuates oxidative stress, and possibly improves psychiatric disorders. This study aimed to evaluate the effects of oral NAC on oxidative stress, depression, and anxiety symptoms in patients with multiple sclerosis (MS).

METHODS

This clinical trial was conducted on 42 MS patients randomly assigned to intervention (n = 21) and control (n = 21) groups. The intervention group received 600 mg of NAC twice daily for 8 weeks, and the control group received a placebo with the same prescription form. An analysis of serum malondialdehyde (MDA), serum nitric oxide (NO), and erythrocyte GSH was carried out on both groups, along with a complete blood count. The Hospital Anxiety and Depression Scale (HADS) was used to assess symptoms of depression (HADS-D) and anxiety (HADS-A).

RESULTS

Compared to the control group, NAC consumption significantly decreased serum MDA concentrations (-0.33 [-5.85-2.50] vs. 2.75 [-0.25-5.22] μmol/L; p = 0.03) and HADS-A scores (-1.6 ± 2.67 vs. 0.33 ± 2.83; p = 0.02). No significant changes were observed in serum NO concentrations, erythrocyte GSH levels, and HADS-D scores (p > 0.05).

CONCLUSIONS

Based on the findings of the present study, NAC supplementation for 8 weeks decreased lipid peroxidation and improved anxiety symptoms in MS patients. The aforementioned results suggest that adjunctive therapy with NAC can be considered an effective strategy for MS management. Further randomized controlled studies are warranted.

Hydrogen Peroxide Inhibits Hepatitis B Virus Replication by Downregulating HBx Levels via Siah-1-Mediated Proteasomal Degradation in Human Hepatoma Cells

The hepatitis B virus (HBV) is constantly exposed to significant oxidative stress characterized by elevated levels of reactive oxygen species (ROS), such as H2O2, during infection in hepatocytes of patients. In this study, we demonstrated that H2O2 inhibits HBV replication in a p53-dependent fashion in human hepatoma cell lines expressing sodium taurocholate cotransporting polypeptide. Interestingly, H2O2 failed to inhibit the replication of an HBV X protein (HBx)-null HBV mutant, but this defect was successfully complemented by ectopic expression of HBx. Additionally, H2O2 upregulated p53 levels, leading to increased expression of seven in absentia homolog 1 (Siah-1) levels. Siah-1, an E3 ligase, induced the ubiquitination-dependent proteasomal degradation of HBx. The inhibitory effect of H2O2 was nearly abolished not only by treatment with a representative antioxidant, N-acetyl-L-cysteine but also by knockdown of either p53 or Siah-1 using specific short hairpin RNA, confirming the role of p53 and Siah-1 in the inhibition of HBV replication by H2O2. The present study provides insights into the mechanism that regulates HBV replication under conditions of oxidative stress in patients.

Effect of MetioNac® in patients with metabolic syndrome who are at risk of metabolic dysfunction associated fatty liver disease: a randomized controlled trial

Introduction

Introduction: metabolic syndrome comprises a combination of diabetes, high blood pressure, and obesity, and metabolic associated fatty liver disease (MAFLD) is associated with it. Objective: to evaluate the effect of supplementation with S-adenosyl-L-methionine + N-acetylcysteine + thioctic acid + vitamin B6 (MetioNac®) for 3 months on lipidic and biochemical parameters in subjects with metabolic syndrome and at risk of MAFLD. The reduction in body weight and the oxidative stress markers malondialdehyde (MDA) and superoxide dismutase (SOD) were also evaluated. Methods: patients with metabolic syndrome, at risk of MAFLD (FIB-4 < 1.30), and with an indication for weight reduction were recruited (n = 15). Control group followed a semipersonalized Mediterranean diet (MD) for weight reduction, according to the recommendations of the Spanish Society for the Study of Obesity (SEEDO). Experimental group, in addition to the MD, took three capsules of MetioNac® supplement per day. Results: compared with the control group, subjects taking MetioNac® showed significant (p < 0.05) reductions in the levels of TG and VLDL-c, as well as in total cholesterol, LDL-c, and glucose levels. They also showed increased levels of HDL-c. Levels of AST and ALT decreased after the intervention with MetioNac®, but this decrease did not reach statistical significance. Weight loss was observed in both groups. Conclusion: supplementation with MetioNac® may be protective against hyperlipidemia, insulin resistance, and overweight among metabolic syndrome patients. Further studies on this issue are needed in a larger population.

Beyond Stereoisomeric Effects: Exploring the Importance of Intermolecular Electron Spin Interactions in Biorecognition

This work shows that electron spin polarization and stereoisomeric effects make comparable contributions to the enantioselective binding of amino acids. Magneto-electrochemical quartz crystal microbalance methods are used to study the adsorption of chiral amino acids onto a monolayer film of chiral molecules that are spin polarized by an underlying ferromagnetic substrate. The direction of the electron spin polarization affects both the kinetics and thermodynamics of the enantiospecific adsorption of the amino acids. Comparison of these data with the circular dichroism (CD) spectra of the amino acid adsorbates shows that the CD spectrum of the interacting group provides a good figure-of-merit for predicting the contributions of electron spin to the intermolecular interaction. These findings demonstrate the importance of electron spin in enantioselective intermolecular interactions between chiral amino acids and represent a paradigm shift for how selectivity should be viewed in biorecognition.

Comparison of Reactive Sites in 2(1H)-Quinolone Derivatives for the Detection of Biologically Important Sulfur Compounds

Novel fluorescent probes based on 2(1H)-quinolone skeleton containing a malonate group (Q1-Q3) were synthesized and proposed for biothiols detection. Their chemical reactivity toward thiols was compared to the reactivity of derivative having a dicyanovinyl group (Q4) as a reactive site. The detailed photophysical properties of these compounds were assessed through the determination of absorption and fluorescence spectra, fluorescence quantum yield, and fluorescence lifetime. In the presence of biothiols, an increase in the fluorescence intensity of compounds Q1-Q3 and a hypsochromic shift in their emission bands were observed. In contrast, the compound with the dicyanovinyl group (Q4) in the presence of biothiols and cyanide ion showed the quenching of fluorescence, while a fluorescence "turn on" effect was observed toward reactive sulfur species.

Non-Invasive Vaccines: Challenges in Formulation and Vaccine Adjuvants

Given the limitations of conventional invasive vaccines, such as the requirement for a cold chain system and trained personnel, needle-based injuries, and limited immunogenicity, non-invasive vaccines have gained significant attention. Although numerous approaches for formulating and administrating non-invasive vaccines have emerged, each of them faces its own challenges associated with vaccine bioavailability, toxicity, and other issues. To overcome such limitations, researchers have created novel supplementary materials and delivery systems. The goal of this review article is to provide vaccine formulation researchers with the most up-to-date information on vaccine formulation and the immunological mechanisms available, to identify the technical challenges associated with the commercialization of non-invasive vaccines, and to guide future research and development efforts.

Extraintestinal Manifestations in Induced Colitis: Controversial Effects of N-Acetylcysteine on Colon, Liver, and Kidney

Ulcerative colitis (UC) is a chronic and recurrent inflammatory bowel disease (IBD) characterized by continuous inflammation in the colonic mucosa. Extraintestinal manifestations (EIM) occur due to the disruption of the intestinal barrier and increased permeability caused by redox imbalance, dysbiosis, and inflammation originating from the intestine and contribute to morbidity and mortality. The aim of this study is to investigate the effects of oral N-acetylcysteine (NAC) on colonic, hepatic, and renal tissues in mice with colitis induced by dextran sulfate sodium (DSS). Male Swiss mice received NAC (150 mg/kg/day) in the drinking water for 30 days before and during (DSS 5% v/v; for 7 days) colitis induction. On the 38th day, colon, liver, and kidney were collected and adequately prepared for the analysis of oxidative stress (superoxide dismutase (SOD), catalase (CAT), glutathione reduced (GSH), glutathione oxidized (GSSG), malondialdehyde (MDA), and hydrogen peroxide (H2O2)) and inflammatory biomarkers (myeloperoxidase (MPO) -, tumor necrosis factor alpha - (TNF-α, and interleukin-10 (IL-10)). In colon, NAC protected the histological architecture. However, NAC did not level up SOD, in contrast, it increased MDA and pro-inflammatory effect (increased of TNF-α and decreased of IL-10). In liver, colitis caused both oxidative (MDA, SOD, and GSH) and inflammatory damage (IL-10). NAC was able only to increase GSH and GSH/GSSG ratio. Kidney was not affected by colitis; however, NAC despite increasing CAT, GSH, and GSH/GSSG ratio promoted lipid peroxidation (increased MDA) and pro-inflammatory action (decreased IL-10). Despite some beneficial antioxidant effects of NAC, the negative outcomes concerning irreversible oxidative and inflammatory damage in the colon, liver, and kidney confirm the nonsafety of the prophylactic use of this antioxidant in models of induced colitis, suggesting that additional studies are needed, and its use in humans not yet recommended for the therapeutic routine of this disease.

Ticlopidine induces embryonic development toxicity and hepatotoxicity in zebrafish by upregulating the oxidative stress signaling pathway

Ticlopidine exerts its anti-platelet effects mainly by antagonizing platelet p2y12 receptors. Previously, a few studies have shown that ticlopidine can induce liver injury, but the exact mechanism of hepatotoxicity remains unclear. Oxidative stress, metabolic disorders, hepatocyte apoptosis, lipid peroxidation, and inflammatory responses can all lead to hepatic liver damage, which can cause hepatotoxicity. In this study, in order to deeply explore the potential molecular mechanisms of ticlopidine -induced hepatotoxicity, we used zebrafish as a model organism to comprehensively evaluate the hepatotoxicity of ticlopidine and its associated mechanism. Three days post-fertilization, zebrafish larvae were exposed to varying concentrations (1.5, 1.75 and 2 μg/mL) of ticlopidine for 72 h, in contrast, adult zebrafish were exposed exposure to 4 μg/mL of ticlopidine for 28 days. Ticlopidine-exposed zebrafish larvae showed changes in liver morphology, shortened body length, and delayed development of the swim bladder development. Liver tissues of ticlopidine-exposed zebrafish larvae and adults stained with Hematoxylin & Eosin revealed vacuolization and increased cellular interstitial spaces in liver tissues. Furthermore, using Oil Red O and periodic acid-Schiff staining methods and evaluating different metabolic enzymes of ticlopidine-exposed zebrafish larvae and adults suggested abnormal liver metabolism and liver injury in both ticlopidine-exposed zebrafish larvae and adults. Ticlopidine also significantly elevated inflammation and oxidative stress and reduced hepatocyte proliferation. During the rescue intervention using N-acetylcysteine, we observed significant improvement in ticlopidine-induced morphological changes in the liver, shortened body length, delayed swim bladder development, and proliferation of liver tissues showed significant improvement. In conclusion, ticlopidine might inhibit normal development and liver proliferation in zebrafish by upregulation of oxidative stress levels, thus leading to embryonic developmental toxicity and hepatotoxicity. In this study, we used zebrafish as a model organism to elucidate the developmental toxicity and hepatotoxicity induced by ticlopidine upregulation of oxidative stress signaling pathway in zebrafish, providing a theoretical basis for clinical application.

Antiplatelet Action of Chloramine Derivatives of Adenosine Phosphates and Their Chemical Activity in Relation to Sulfur-Containing Compounds

We studied the properties of N6-chloroadenosine phosphates (ATP, ADP, and AMP chloramines) as compounds with potentially increased antiplatelet efficacy determined by their binding to the plasma membrane of platelets. Chloramine derivatives of ATP, ADP, and AMP do not differ in their optical absorption characteristics: their absorption spectra are in the range of 220-340 nm with a maximum at 264 nm. Chloramines of adenosine phosphates are characterized by high reactivity with respect to thiol compounds. In particular, the rate constants of the reaction of N6-chloroadenosine-5'-diphosphate with N-acetylcysteine, reduced glutathione, dithiothreitol, and cysteine reach 59,000, 250,000, 340,000, and 1,250,000 M^-1×sec^-1, respectively, and only 1.10±0.02 M^-1×sec^-1 with methionine. It has been found that N6-chloradenosine-5'-triphosphate is a strong inhibitor of platelet functions: it effectively suppresses ADP-induced cell aggregation (IC₅₀ in the whole blood is 5 μM) and inhibits aggregation of preactivated platelets and induces dissociation of their aggregates.

N-acetylcysteine Amide AD4/NACA and Thioredoxin Mimetic Peptides Inhibit Platelet Aggregation and Protect against Oxidative Stress

In the present study, we tested the effect of small-molecular-weight redox molecules on collagen-induced platelet aggregation. We used N-acetylcysteine amide (AD4/NACA), the amide form of N-acetylcysteine (NAC), a thiol antioxidant with improved lipophilicity and bioavailability compared to NAC, and the thioredoxin-mimetic (TXM) peptides, TXM-CB3, TXM-CB13, and TXM-CB30. All compounds significantly inhibited platelet aggregation induced by collagen, with TXM-peptides and AD4 being more effective than NAC. The levels of TxB₂ and 12-HETE, the main metabolites derived from the cyclooxygenase and lipoxygenase pathways following platelet activation, were significantly reduced in the presence of AD4, TXM peptides, or NAC, when tested at the highest concentration (0.6 mM). The effects of AD4, TXM-peptides, and NAC were also tested on the clotting time (CT) of whole blood. TXM-CB3 and TXM-CB30 showed the greatest increase in CT. Furthermore, two representative compounds, TXM-CB3 and NAC, showed an increase in the anti-oxidant free sulfhydryl groups of plasma detected via Ellman's method, suggesting a contribution of plasma factors to the antiaggregating effects. Our results suggest that these small-molecular-weight redox peptides might become useful for the prevention and/or treatment of oxidative stress conditions associated with platelet activation.

Selenium supplementation provides potent neuroprotection following cerebral ischemia in mice

Despite progress in reperfusion therapy, functional recovery remains suboptimal in many stroke patients, with oxidative stress, inflammation, dysbiosis, and secondary neurodegeneration constituting the major hurdles to recovery. The essential trace element selenium is emerging as a promising therapeutic agent for stroke. However, although several rodent studies have shown that selenium can protect against cell loss following cerebral ischemia, no study has yet examined whether selenium can enhance long-term functional recovery. Moreover, published studies have typically reported a single mechanism of action underlying selenium-mediated stroke recovery. However, we propose that selenium is more likely to have multifaceted actions. Here, we show that selenomethionine confers a potent neuroprotective effect in a canonical filament-induced transient middle cerebral artery occlusion (tMCAO) mouse model. Post-tMCAO selenium treatment significantly reduces the cerebral infarct volume, oxidative stress, and ferroptosis and enhances post-tMCAO motor performance in the acute phase after stroke. Moreover, analysis of the gut microbiota reveals that acute selenium treatment reverses stroke-induced gut dysbiosis. Longer-term selenium supplementation activates intrinsic neuroprotective mechanisms, prevents secondary neurodegeneration, alleviates systemic inflammation, and diminishes gut microbe-derived circulating trimethylamine N-oxide. These findings demonstrate that selenium treatment even after cerebral ischemia has long-term and multifaceted neuroprotective effects, highlighting its clinical potential.