acetylcysteine

The conversion of solar energy (SEC) to storable chemical energy by photosynthesis has been performed by photosynthetic organisms, including oxygenic cyanobacteria for over 3 billion years. We have previously shown that crude thylakoid membranes from the cyanobacterium Synechocytis sp. PCC 6803 can reduce the electron transfer (ET) protein cytochrome c even in the presence of the PSII inhibitor DCMU. Mutation of lysine 238 of the Photosystem II D1 protein to glutamic acid increased the cytochrome reduction rates, indicating the possible position of this unknown ET pathway. In this contribution, we show that D1-K238E is rather unique, as other mutations to K238, or to other residues in the same vicinity, are not as successful in cytochrome c reduction. This observation indicates the sensitivity of ET reactions to minor changes. As the next step in obtaining useful SEC from biological material, we describe the use of crude Synechocystis membranes in a bio-photovoltaic cell containing ...

INTRODUCTION Delayed graft function (DGF) is a consequence of ischemia-reperfusion injuries in kidney allografts, for which no definite treatment is available. The neutrophil gelatinase-associated lipocalin (NGAL) and interleukin-18 (IL-18) are introduced as the most promising urine biomarkers to detect DGF. N-acetylcysteine (NAC) and vitamin C, well-known potent antioxidants that scavenge free radicals, may alleviate kidney injury. This study investigated the protective effects of NAC alone and in combination with vitamin C on DGF, by measuring IL-18 and NGAL in living donor kidney transplantations. MATERIALS AND METHODS Patients transplanted between January 2011 and February 2013 were randomly divided into 3 groups to receive routine anti-rejection medication only (n = 32), NAC plus routine immunosuppressive regimen (NAC group; n = 33), and NAC and vitamin C plus routine regimen (NAC and vitamin C group; n = 19). Urine samples were taken 4 hours and 24 hours after transplantation....

Objective— Phosphatidylcholine hydroxyalkenals (PC-HAs) are a class of oxidized PCs derived from lipid peroxidation of arachidonate or linoleate at the sn -2 position to form terminal γ-hydroxy, α-, and β-unsaturated aldehydes. The aim of this study was to characterize some of their biological properties, ascertain the mechanism of their action, and assess whether they have in vivo relevance. Methods and Results— Combinations of cell biological approaches with radiolabels, mass spectroscopy, and immunochemical as well as immunohistochemical techniques were used to show that PC-HAs reduce the proteolytic degradation by mouse peritoneal macrophages (MPMs) of internalized macromolecules, such as maleylated bovine serum albumin, and that the activity of the lysosomal protease, cathepsin B, in MPMs form Michael adducts with MPM proteins and with N -acetylated cysteine in vitro form pyrrole adducts with MPM proteins and reduce the maturation of Rab5a, thereby impairing phagosome-lysosome ...

Efficacy of thiol chelators viz. N-acetyl cysteine and D-penicillamine (NAC and DPA) along with nutritional supplements viz. zinc acetate, sodium selenite and magnesium sulphate (Zn, Se and Mg) in the treatment of mercury intoxication was investigated in rats. This is of particular interest since high bonding affinity between mercuric ion and the thiol group exits. The mutual antagonism of mercury and selenium is one of the strongest examples of the interaction in the trace element field. Adult rats of Sprague-Dawley strain were administered a bolus dose of dimethyl mercury (10 mg/kg) orally. A significant rise in the aspartate aminotransferase, alanine aminotransferase, serum alkaline phosphatase, lactate dehydrogenase, gamma glutamyltranspeptidase, bilirubin and creatinine were observed. Single mercury exposure also resulted in a significant increase in lipid peroxides with a concomitant decrease in reduced glutathione level in liver, kidney and brain. A decrease in the enzymatic ...

Hyperoxia-induced lung injury is well known in animal and human studies. We have previously shown that hyperoxic exposure of guinea pigs is associated with suppression of cough reflex. The goal of this study was to determine the effects of oral N-acetylcysteine (NAC) on hyperoxia-induced oxidative stress in lung tissue directed on cough reflex. The experimental group was pretreated with NAC daily for 7 days and subsequently exposed to 100% O2 for 60 h. Hyperoxic group inhaled 100% O2 only. The control group was exposed to normoxia. Cough was induced by inhalation of citric acid aerosol before and after exposure to oxygen. Cough was also induced by mechanical stimulation of airways in anesthetized animals just after the end of oxygen exposure. Our results showed a significant decrease (P=0.002) in citric acid-induced cough in hyperoxic animals and reversal of that effect in animals pretreated with NAC. In addition, there was a significant interaction between antioxidant therapy and h...

Methods and Results— We investigated the metabolic and hemodynamic effects of intravenous administration of acetylcysteine, a thiol-containing antioxidant, during a hemodialysis session in a prospective, randomized, placebo-controlled crossover study in 20 patients with end-...

N-acetylcysteine (NAC), a mucolytic and antioxidant, is speculated to cause bronchoconstriction in cats when delivered via aerosol. We hypothesized that in cats with experimental asthma, aerosol delivery of NAC (400 mg cumulative dose) via an endotracheal tube would increase airflow limitation as measured by ventilator-acquired mechanics. After endotracheal drug delivery, airway resistance and inspiratory plateau pressure (Pplat) measurements were obtained in six mechanically ventilated asthmatic cats. Results demonstrated significantly increased airway resistance ( P=0.0007) compared with aerosolized saline control; Pplats were not significantly different ( P=0.059). All cats exhibited at least one adverse effect: excessive airway secretions ( n=3), spontaneous cough ( n=2), unilateral strabismus ( n=1) and post-anesthetic death ( n=1). No adverse reactions were noted with saline aerosol; cough was noted in one cat with methacholine challenge. In conclusion, airway resistance and a...

Ischemia due to transient splanchnic vasoconstriction following major burns causes oxidative and/or nitrosative damage in intestinal tissue followed by reperfusion injury. Thus, burn injury leads to breakdown in the intestinal mucosal barrier which can induce bacterial translocation (BT). As an antioxidant and anti-inflammatory agent the protective effects of N-acetylcysteine (NAC) are documented in several studies. This study was designed to determine the effect of NAC treatment on the oxidative stress in the intestine and BT after ...

To assess the effect of high-dose N-acetylcysteine on renal function in cardiac surgery patients at higher risk of postoperative renal failure. Multiblind, placebo-controlled, randomized, phase II clinical trial. Operating rooms and intensive care units of two tertiary referral hospitals. A total of 60 cardiac surgery patients at higher risk of postoperative renal failure. Patients were allocated to either 24 hrs of high-dose N-acetylcysteine infusion (300 mg/kg body weight in 5% glucose, 1.7 L) or placebo (5% glucose, 1.7 L). The primary outcome measure was the absolute change in serum creatinine from baseline to peak value within the first five postoperative days. Secondary outcomes included the relative change in serum creatinine, peak serum creatinine level, serum cystatin C, and in urinary output. Further outcomes were needed for renal replacement therapy, length of ventilation, and length of stay in the intensive care unit and hospital. Randomization was successful and patients were well balanced for preoperative and intraoperative characteristics. There was no significant attenuation in the increase in serum creatinine from baseline to peak when comparing N-acetylcysteine with placebo (64.5 +/- 91.2 and 38.0 +/- 42.4 mumol/L, respectively; p = .15). Also, there was no attenuation in the increase in serum cystatin C from baseline to peak for N-acetylcysteine compared with placebo (0.45 +/- 0.43 and 0.30 +/- 0.33 mg/L, respectively; p = .40). Likewise, there was no evidence for differences in any other clinical outcome. In this phase II, randomized, controlled trial, high-dose N-acetylcysteine was no more effective than placebo in attenuating cardiopulmonary bypass-related acute renal failure in high-risk cardiac surgery patients.

Background Perinatal exposure to hyperhomocysteinemia might disturb neurogenesis during brain development and growth. Also, high levels of homocysteine trigger neurodegeneration in several experimental models. However, the putative mechanisms of homocysteine-induced toxicity in the developing nervous system have poorly been elucidated. This study was aimed to investigate homocysteine effects in undifferentiated neuroblastoma cells, Neuro2a. Results A 4 h exposure to homocysteine in a concentration range of 10–100 μM did not affect cell viability and ROS production in Neuro2a cell cultures. Instead, ROS levels were increased by two-three folds in cells treated with 250 μM and 500 μM homocysteine, respectively, in comparison with control cells. Also, the highest homocysteine dose significantly reduced the viable cell number by 40%. Notably, the treatment with homocysteine (250 μM–500 μM) in the presence of antioxidants, such as N-acetylcysteine and IRFI 016, a synthetic α-tocopherol a...

Apoptosis is considered to be involved in the normal regulation of the organ size, as well as in the underlying mechanism of cell death in liver diseases. The induction of oxidative stress is a key event in the intracellular pathways leading to cellular apoptosis [1]. Several free ...

Oxidative stress has a proven role in pathophysiology of acute respiratory distress syndrome. The antioxidant drugs, especially N-acetylcysteine (NAC) have been used for years to overcome oxidative stress effects in patients. In the present study we have investigated the effects of NAC treatment (IV NAC in 150mg/kg at the first day followed by 50mg/kg/day for three days) on 27 ICU patients with ALI/ARDS considering the glutathione-S-transferase genetic variations, as an important enzyme contributing in oxidative stress pathways. The results indicated that NAC improved oxygenation (increase in PaO(2)/FiO(2)) and decreased mortality rate in treated patients compared to control group (p<0.05). Evaluation of three isoforms of glutathione-S-transferase (GST M1, P1 and T1), in these patients have showed an association between GST M1 null, and GST M1 and T1 double null polymorphisms with increased mortality in control group, suggesting antioxidant therapy critical for this group of pati...

N-acetylcysteine (NAC) is an anti-oxidant drug that has been used as a mucolytic agent and a paracetamol antidote for many years. This study was designed to determine the efficacy of the adjunctive use of NAC for periodontal treatment. Thirty subjects with moderate-to-severe chronic periodontitis were randomized to surgery with NAC (600 mg; S-NAC), surgery only (S-nonNAC), and healthy control groups. Gingival crevicular fluid (GCF) samples were obtained from all patients and sRANKL levels were determined by enzyme-linked immunosorbent assay at baseline, and 1, 3, and 7 months post-surgery. Plaque and gingival indices, probing depths, and clinical attachment levels were recorded at the same time. There was a significant reduction in probing depth at 3 months in the S-NAC group when compared to the S-nonNAC group (P < 0.05). However, no statistically significant differences in plaque and gingival indices, probing depths, clinical attachment levels, and sRANKL levels in GCF were not...

Diabetes-induced glutathione (GSH) decrease is usually ascribed to GSH oxidation. Here we investigate, in streptozotocin-treated rats, if impairment of GSH synthesis contributes to GSH decrease in diabetic liver, and if antioxidant treatments can provide protection. Diabetic rats were divided into 3 groups: untreated diabetic rats (UD); N-acetyl-cysteine (NAC)-treated diabetic rats; taurine (TAU)-treated diabetic rats; a group of non-streptozotocin-treated rats was used as control (CTR). All rats were sacrificed at 40 weeks of age. Diabetes induced hepatic glutathione decrease, but oxidized glutathione (GSSG) did not increase significantly. Accumulations of cysteine and cysteinyl-glycine in UD suggest respectively decreased glutathione synthesis and increased loss through the plasma membrane with subsequent degradation. Decreased expression of γ-glutamyl-cysteine synthetase in UD is consistent with repressed GSH synthesis. Moreover, diabetes caused increase of GSSG/GSH ratio and ind...

Signal transduction in response to several growth factors that regulate oligodendrocyte development and survival involves the activation of phosphatidylinositol 3-kinase, which we detect in oligodendrocytes and their precursors. To investigate the role of this enzyme activity, we analyzed cell survival in cultures of oligodendrocytes treated with wortmannin or LY294002, two potent inhibitors of phosphatidylinositol 3-kinase. Cell survival was inhibited by 60–70% in these cultures within 24 hours, as quantitated by a tetrazolium staining assay for viable cells and by measurement of DNA content. Similar results were obtained with oligodendrocyte precursor cells. Nuclei of the dying cells contained fragmented DNA, as revealed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assays, indicating that the cells were dying by apoptosis. Moreover, a significant increase in the number of cells with fragmented nuclear DNA was detected as early as 4 hours, well be...

The goals of this study were to evaluate the effects of ionizing radiation on apical junctions in colonic epithelium and mucosal barrier function in mice in vivo. Adult mice were subjected to total body irradiation (4 Gy) with or without N-acetyl-l-cysteine (NAC) feeding for 5 days before irradiation. At 2–24 h postirradiation, the integrity of colonic epithelial tight junctions (TJ), adherens junctions (AJ), and the actin cytoskeleton was assessed by immunofluorescence microscopy and immunoblot analysis of detergent-insoluble fractions for TJ and AJ proteins. The barrier function was evaluated by measuring vascular-to-luminal flux of fluorescein isothiocyanate (FITC)-inulin in vivo and luminal-to-mucosal flux in vitro. Oxidative stress was evaluated by measuring protein thiol oxidation. Confocal microscopy showed that radiation caused redistribution of occludin, zona occludens-1, claudin-3, E-cadherin, and β-catenin, as well as the actin cytoskeleton as early as 2 h postirradiation...

The rate of reepithelialization of the rabbit cornea, receiving isotonic NaCl solution and acetylcysteine (Mucomyst) solution at 10 and 20% concentrations, following a superficial epithelial ulcer was studied by fluorescein staining, photography and light microscopy. Acetylcysteine solution does not seem to retard normal epithelial healing compared with control animals which received isotonic NaCl solution.