N-acetylcysteine Reduces Inflammasome Activation Induced by SARS-CoV-2 Proteins In Vitro

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.

Clinical efficacy of N-acetylcysteine for COVID-19: A systematic review and meta-analysis of randomized controlled trials

Background

The association between N-acetylcysteine (NAC) and COVID-19 remains undetermined; therefore, this meta-analysis assessed the clinical efficacy of NAC in the treatment of patients with COVID-19.

Methods

This study searched PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov for studies published from their inception to December 17, 2022. Only randomized controlled trials (RCTs) that assessed the clinical efficacy of NAC for patients with COVID-19 were included.

Results

Five RCTs involving 651 patients were included. There was no significant difference in mortality between the study group receiving NAC and the control group (15.6 % [50/320] vs. 32.3 %, [107/331]; risk ratio [RR]: 0.58; 95 % confidence interval [CI]: 0.24-1.40). In addition, the two groups did not differ with respect to the incidence of invasive mechanical ventilation (RR: 0.93; 95 % CI: 0.65-1.33), the risk of intensive care unit (ICU) admission (RR: 0.86; 95 % CI: 0.62-1.21), the length of hospital stay (mean difference [MD]: 0.17 days; 95 % CI: -0.67-1.01), and the length of ICU stay (MD: -0.77 days; 95 % CI: -2.97-1.42).

Conclusions

The administration of NAC did not improve the clinical outcomes of patients with COVID-19; its routine use is not recommended for patients with SARS-CoV-2 infections.

Evaluation of the efficacy of N-acetylcysteine and bromhexine compared with standard care in preventing hospitalization of outpatients with COVID-19: a double blind randomized clinical trial

INTRODUCTION AND AIM

Since its emergence in December 2019, the coronavirus disease caused by the severe acute respiratory syndrome coronavirus 2 has become a global emergency, spreading rapidly worldwide. In response to the early referral of these patients to outpatient health centers, we decided to seek more effective treatments in the early stages of their referral. This study aims to prevent both the progression and deterioration of the physical conditions of COVID-19 patients, reduce the rate of referrals, and mitigate the risks of hospitalization and death.

MATERIAL AND METHODS

Conducted at Dibaj Therapeutic Center, Hamadan City, Iran, a double-blind randomized controlled trial encompassed 225 COVID-19 patients from April to September 2022. Ethical approval was obtained from Hamadan University of Medical Sciences (Approval No.: IR.UMSHA.REC.1400.957), with the protocol registered in the Iranian Registry of Clinical Trials (Registration No. : IRCT20220302054167N1). In this study, we included patients who tested positive for COVID-19- PCR and were symptomatic, excluding those who were pregnant or had received a COVID-19 vaccine. Patients with oxygen saturation above 92% were allocated to three groups: Group A received N-acetylcysteine, Group B received Bromhexine, and Group C received standard care. Follow-ups on oxygen levels, symptoms, and hospitalization needs were conducted on days 7 and 14, with hospitalized patients monitored for one month post-hospitalization.

RESULTS

The study found that both N-acetylcysteine and Bromhexine can effectively reduce hospitalization rates and mortality and shorten the duration of hospitalization. The third visit of patients who received N-acetylcysteine showed an increase of 1.33% in oxygen saturation compared to their first visit, and in patients who received Bromhexine, this increase was 1.19%. The mortality rate was 9.33% in the control group and zero in both groups of patients who received medication.

CONCLUSION

In conclusion, the results of this study indicate that NAC and bromhexine may be effective in the treatment of patients with positive COVID-19, with a lower hospitalization rate, shorter hospitalization, faster recovery time, and reduced mortality compared to the control group.

Role of NLRP3 inflammasome in diabetes and COVID-19 role of NLRP3 inflammasome in the pathogenesis and treatment of COVID-19 and diabetes NLRP3 inflammasome in diabetes and COVID-19 intervention

2019 Coronavirus Disease (COVID-19) is a global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). A "cytokine storm", i.e., elevated levels of pro-inflammatory cytokines in the bloodstream, has been observed in severe cases of COVID-19. Normally, activation of the nucleotide-binding oligomeric domain-like receptor containing pyrin domain 3 (NLRP3) inflammatory vesicles induces cytokine production as an inflammatory response to viral infection. Recent studies have found an increased severity of necrobiosis infection in diabetic patients, and data from several countries have shown higher morbidity and mortality of necrobiosis in people with chronic metabolic diseases such as diabetes. In addition, COVID-19 may also predispose infected individuals to hyperglycemia. Therefore, in this review, we explore the potential relationship between NLRP3 inflammatory vesicles in diabetes and COVID-19. In contrast, we review the cellular/molecular mechanisms by which SARS-CoV-2 infection activates NLRP3 inflammatory vesicles. Finally, we propose several promising targeted NLRP3 inflammatory vesicle inhibitors with the aim of providing a basis for NLRP3-targeted drugs in diabetes combined with noncoronary pneumonia in the clinical management of patients.

Impact of N-Acetylcysteine in the mortality of patients hospitalized with COVID-19: a retrospective cohort study

INTRODUCTION AND AIM

N-Acetylcysteine has been proposed for the treatment of COVID-19 thanks to its mucolytic, antioxidant and anti-inflammatory effects. Our aim is to evaluate its effect on patients admitted with COVID-19 in mortality terms.

MATERIAL AND METHODS

Retrospective single-center cohort study. All patients admitted to our hospital for COVID-19 from March to April 2020 have been considered.

RESULTS

A total of 378 patients were included, being 196 (51.9%) men, with an average age of 73.3±14.5 years. 52.6% (199) received treatment with N-Acetylcysteine. More than 70% presented coughs, fever, and/or dyspnea. The global hospital mortality was 26.7%. A multivariate analysis through logistic regression identified the age of patients [older than 80; OR: 8.4 (CI95%:3-23.4)], a moderate or severe radiologic affectation measured by the RALE score [OR:7.3 (CI95%:3.2-16.9)], the tobacco consumption [OR:2.8 (CI95%:1.3-6.1)] and previous arrhythmia [OR 2.8 (CI95%: 1.3-6.2)] as risk factor that were independently associated with mortality during the admission. The treatment with N-Acetylcysteine was identified as a protective factor [OR: 0.57 (CI95%: 0.31-0.99)]. Asthma also seems to have a certain protective factor although it was not statistically significant in our study [OR: 0.19 (CI95%: 0.03-1.06)].

CONCLUSIONS

Patients with COVID-19 treated with N-acetylcysteine have presented a lower mortality and a better evolution in this study. Future prospective studies or randomized clinical trials must confirm the impact of N-Acetylcysteine on COVID-19 patients.

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.

The role of N-acetylcysteine in decreasing neutrophil-lymphocyte ratio in COVID-19 patients: A double-blind, randomized controlled trial

N-acetylcysteine has antioxidant and anti-inflammatory activities that could potentially improve the clinical outcomes of coronavirus disease 2019 (COVID-19) patients. N-acetylcysteine potentially inhibits NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome and results in control oxidative stress and cytokine release in COVID-19 patients. The aim of this study was to assess the effect of N-acetylcysteine in reducing the neutrophil-lymphocyte ratio (NLR) in COVID-19 patients. A randomized controlled clinical trial was conducted among severe and moderate COVID-19 patients. The treatment group received oral 1200 mg daily of N-acetylcysteine (three times a day) and the standard care for COVID-19, while the control group received standard care for COVID-19 and a placebo. The NLR was determined on the first day of admission and after the seventh day of treatment. A paired Student t-test was used to compare the NLR before and after treatment while independent Student t-test was used to compare the NLR between treatment and control groups. A total of 40 severe and moderate COVID-19 were enrolled, 20 people in each group, with a mean age was 44.68±13.24 years old. The mean NLR on the first day was 9.44 in the treatment group and 8.84 in the control group. After the seventh day, the mean NLR was 4.27 and 11.54 in the treatment group and control group, respectively. The mean changes of NLR (the pre-treatment compared to post-treatment) in the treatment and control group were reduced 4.05 and increased 3.34, respectively. The NLR in treatment group significantly decreased compared to the control group (p<0.001). In conclusion, N-acetylcysteine 1200 mg daily could reduce the NLR in severe and moderate COVID-19 patients.

Inflammasomes: a rising star on the horizon of COVID-19 pathophysiology

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a contagious respiratory virus that is the cause of the coronavirus disease 2019 (COVID-19) pandemic which has posed a serious threat to public health. COVID-19 is characterized by a wide spectrum of clinical manifestations, ranging from asymptomatic infection to mild cold-like symptoms, severe pneumonia or even death. Inflammasomes are supramolecular signaling platforms that assemble in response to danger or microbial signals. Upon activation, inflammasomes mediate innate immune defense by favoring the release of proinflammatory cytokines and triggering pyroptotic cell death. Nevertheless, abnormalities in inflammasome functioning can result in a variety of human diseases such as autoimmune disorders and cancer. A growing body of evidence has showed that SARS-CoV-2 infection can induce inflammasome assembly. Dysregulated inflammasome activation and consequent cytokine burst have been associated with COVID-19 severity, alluding to the implication of inflammasomes in COVID-19 pathophysiology. Accordingly, an improved understanding of inflammasome-mediated inflammatory cascades in COVID-19 is essential to uncover the immunological mechanisms of COVID-19 pathology and identify effective therapeutic approaches for this devastating disease. In this review, we summarize the most recent findings on the interplay between SARS-CoV-2 and inflammasomes and the contribution of activated inflammasomes to COVID-19 progression. We dissect the mechanisms involving the inflammasome machinery in COVID-19 immunopathogenesis. In addition, we provide an overview of inflammasome-targeted therapies or antagonists that have potential clinical utility in COVID-19 treatment.

Identifying key genes related to inflammasome in severe COVID-19 patients based on a joint model with random forest and artificial neural network

Background

The coronavirus disease 2019 (COVID-19) has been spreading astonishingly and caused catastrophic losses worldwide. The high mortality of severe COVID-19 patients is an serious problem that needs to be solved urgently. However, the biomarkers and fundamental pathological mechanisms of severe COVID-19 are poorly understood. The aims of this study was to explore key genes related to inflammasome in severe COVID-19 and their potential molecular mechanisms using random forest and artificial neural network modeling.

Methods

Differentially expressed genes (DEGs) in severe COVID-19 were screened from GSE151764 and GSE183533 via comprehensive transcriptome Meta-analysis. Protein-protein interaction (PPI) networks and functional analyses were conducted to identify molecular mechanisms related to DEGs or DEGs associated with inflammasome (IADEGs), respectively. Five the most important IADEGs in severe COVID-19 were explored using random forest. Then, we put these five IADEGs into an artificial neural network to construct a novel diagnostic model for severe COVID-19 and verified its diagnostic efficacy in GSE205099.

Results

Using combining P value < 0.05, we obtained 192 DEGs, 40 of which are IADEGs. The GO enrichment analysis results indicated that 192 DEGs were mainly involved in T cell activation, MHC protein complex and immune receptor activity. The KEGG enrichment analysis results indicated that 192 GEGs were mainly involved in Th17 cell differentiation, IL-17 signaling pathway, mTOR signaling pathway and NOD-like receptor signaling pathway. In addition, the top GO terms of 40 IADEGs were involved in T cell activation, immune response-activating signal transduction, external side of plasma membrane and phosphatase binding. The KEGG enrichment analysis results indicated that IADEGs were mainly involved in FoxO signaling pathway, Toll-like receptor, JAK-STAT signaling pathway and Apoptosis. Then, five important IADEGs (AXL, MKI67, CDKN3, BCL2 and PTGS2) for severe COVID-19 were screened by random forest analysis. By building an artificial neural network model, we found that the AUC values of 5 important IADEGs were 0.972 and 0.844 in the train group (GSE151764 and GSE183533) and test group (GSE205099), respectively.

Conclusion

The five genes related to inflammasome, including AXL, MKI67, CDKN3, BCL2 and PTGS2, are important for severe COVID-19 patients, and these molecules are related to the activation of NLRP3 inflammasome. Furthermore, AXL, MKI67, CDKN3, BCL2 and PTGS2 as a marker combination could be used as potential markers to identify severe COVID-19 patients.