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

Management of Chronic Heart Failure in Dialysis Patients: A Challenging but Rewarding Path

Chronic heart failure (CHF) is a common complication and cause of death in dialysis patients. Although several clinical guidelines and expert consensus on heart failure (HF) in the general population have been issued in China and abroad, due to abnormal renal function or even no residual renal function (RRF) in dialysis patients, the high number of chronic complications, as well as the specificity, variability, and limitations of hemodialysis (HD) and peritoneal dialysis (PD) treatments, there are significant differences between dialysis patients and the general population in terms of the treatment and management of HF. The current studies are not relevant to all dialysis-combined HF populations, and there is an urgent need for high-quality studies on managing HF in dialysis patients to guide and standardize treatment. After reviewing the existing guidelines and literature, we focused on the staging and diagnosis of HF, management of risk factors, pharmacotherapy, and dialysis treatment in patients on dialysis. Based on evidence-based medicine and clinical trial data, this report reflects new perspectives and future trends in the diagnosis and treatment of HF in dialysis patients, which will further enhance the clinicians' understanding of HF in dialysis patients.

N-Acetylcysteine to Reduce Mortality for Patients Requiring Cardiac Catheterization or Cardiac Surgery: A Systematic Review and Meta-analysis

ABSTRACT

Multimers of von Willebrand factor play a critical role in various processes inducing morbidity and mortality in cardiovascular-risk patients. With the ability to reduce von Willebrand factor multimers, N-acetylcysteine (NAC) could reduce mortality in patients undergoing coronary catheterization or cardiac surgery. However, its impact in perioperative period has never been studied so far in regard of its potential cardiovascular benefits. Then, 4 databases were searched for randomized controlled trials that compared in-hospital mortality between an experimental group, with NAC, and a control group without NAC, in patients undergoing coronary catheterization or cardiac surgery. The primary efficacy outcome was in-hospital mortality. Secondary outcomes were the occurrence of thrombotic events, major cardiovascular events, myocardial infarction, and contrast-induced nephropathy. The safety outcome was occurrence of hemorrhagic events. Nineteen studies totaling 3718 patients were included. Pooled analysis demonstrated a reduction of in-hospital mortality associated with NAC: odds ratio, 0.60; 95% confidence interval, 0.39-0.92; P = 0.02. The occurrence of secondary outcomes was not significantly reduced with NAC except for contrast-induced nephropathy. No difference was reported for hemorrhagic events. Subgroup analyses revealed a life-saving effect of NAC in a dose-dependent manner with reduction of in-hospital mortality for the NAC high-dose group, but not for the NAC standard-dose (<3500-mg) group. In conclusion, without being able to conclude on the nature of the mechanism involved, our review suggests a benefit of NAC in cardiovascular-risk patients in perioperative period in terms of mortality and supports prospective confirmatory studies.

LC-MS/MS determination of N-acetyl-l-cysteine in chicken plasma

N-acetyl-l-cysteine (NAC) shows beneficial effects in cases of aflatoxicosis and heat stress in poultry but little is known about its pharmacokinetics in chickens. Therefore, the study aimed to develop and validate a sensitive LC-MS/MS analytical method for quantitative analysis of NAC in chicken plasma. A split calibration curve approach was used for determination of NAC in chicken plasma. Standard curves for low (0.05-2.5 μg/ml) and high (2.5-100 μg/ml) ranges of concentrations were prepared. The standard curves for low (r2 = 0.9987) and high (r2 = 0.9899) concentrations were linear within the tested range. The limits of detection (LOD) and of quantification (LOQ) for the standard at low concentrations were 0.093 and 0.28 μg/ml, respectively. The accuracy was from 97.35 to 101.33%. The values of LOD and LOQ for the standard at high concentrations were 0.76 and 2.30 μg/ml, respectively. The accuracy was between 99.77 and 112.14%. The intra- and inter-day precisions for all concentrations from both standards did not exceed 8.57% and 10.69%, respectively. The recovery for all concentrations was between 92.45 and 105.52%. The validated method for determination of NAC in chicken plasma can be applied in future pharmacokinetic studies in chickens without dilution of samples and their repeated analysis.

Metabolic Communication by SGLT2 Inhibition

BACKGROUND

SGLT2 (sodium-glucose cotransporter 2) inhibitors (SGLT2i) can protect the kidneys and heart, but the underlying mechanism remains poorly understood.

METHODS

To gain insights on primary effects of SGLT2i that are not confounded by pathophysiologic processes or are secondary to improvement by SGLT2i, we performed an in-depth proteomics, phosphoproteomics, and metabolomics analysis by integrating signatures from multiple metabolic organs and body fluids after 1 week of SGLT2i treatment of nondiabetic as well as diabetic mice with early and uncomplicated hyperglycemia.

RESULTS

Kidneys of nondiabetic mice reacted most strongly to SGLT2i in terms of proteomic reconfiguration, including evidence for less early proximal tubule glucotoxicity and a broad downregulation of the apical uptake transport machinery (including sodium, glucose, urate, purine bases, and amino acids), supported by mouse and human SGLT2 interactome studies. SGLT2i affected heart and liver signaling, but more reactive organs included the white adipose tissue, showing more lipolysis, and, particularly, the gut microbiome, with a lower relative abundance of bacteria taxa capable of fermenting phenylalanine and tryptophan to cardiovascular uremic toxins, resulting in lower plasma levels of these compounds (including p-cresol sulfate). SGLT2i was detectable in murine stool samples and its addition to human stool microbiota fermentation recapitulated some murine microbiome findings, suggesting direct inhibition of fermentation of aromatic amino acids and tryptophan. In mice lacking SGLT2 and in patients with decompensated heart failure or diabetes, the SGLT2i likewise reduced circulating p-cresol sulfate, and p-cresol impaired contractility and rhythm in human induced pluripotent stem cell-derived engineered heart tissue.

CONCLUSIONS

SGLT2i reduced microbiome formation of uremic toxins such as p-cresol sulfate and thereby their body exposure and need for renal detoxification, which, combined with direct kidney effects of SGLT2i, including less proximal tubule glucotoxicity and a broad downregulation of apical transporters (including sodium, amino acid, and urate uptake), provides a metabolic foundation for kidney and cardiovascular protection.

Effects of N-acetyl-L-cysteine against apical periodontitis in rats with adriamycin-induced cardiomyopathy and nephropathy

AIM

This study aimed to investigate the potential protective effects of N-acetyl-L-cysteine (NAC) against apical periodontitis (AP) in rats with adriamycin (ADR)-induced kidney and heart diseases.

METHODOLOGY

Fourty-eight Wistar albino rats were divided into six groups: (1) Control group, (2) ADR group (1 mg/kg/day ip for 10 days), (3) AP Group (1st mandibular molar tooth), (4) AP + ADR Group, (5) AP + NAC group (150 mg/kg/day ip), and (6) AP + ADR + NAC group. After 3 weeks, the rats were decapitated and blood and tissue samples (heart, kidney, and jaw) were collected. Tissue samples were evaluated by biochemical (inflammatory cytokines and hemodynamic parameters) and radiological analyses. One-way anova with Tukey post hoc tests was used to compare data, considering p < .05 as statistically significant.

RESULTS

The serum levels of TNF-α, IL-1β, BUN, Creatinine, CK, and LDH were elevated in the test groups compared with the control group, and treatment with NAC reduced these levels (p < .05). Heart and kidney tissue analysis showed a higher heart-to-body weight ratio (HW/BW) and kidney-to-body weight ratio (KW/BW) in the test groups compared with the control group (p < .05). No significant differences in HW/BW and KW/BW were found between the control and AP + NAC groups. Volumetric apical bone resorption analysis showed an increase in periapical radiolucencies in AP-induced groups indicating apical periodontitis. NAC treatment reduced the total area and volume of resorption cavities (p < .05).

CONCLUSIONS

The results suggest that NAC's antioxidant and anti-inflammatory effects can reduce adriamycin-mediated heart and kidney damage and may have a positive effect on apical periodontitis in individuals with nephropathy and cardiomyopathy.

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

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