N-acetylcysteine Solution Research Articles

Impact of Thermo-Responsive N-Acetylcysteine Hydrogel on Dermal Wound Healing and Oral Ulcer Regeneration.

This study investigates the efficacy of a thermo-responsive N-acetylcysteine (NAC) hydrogel on wound healing and oral ulcer recovery. Formulated by combining NAC with methylcellulose, the hydrogel's properties were assessed for temperature-induced gelation and cell viability using human fibroblast cells. In vivo experiments on Sprague Dawley rats compared the hydrogel's effects against saline, NAC solution, and a commercial NAC product. Results show that a 5% NAC and 1% methylcellulose solution exhibited optimal outcomes. While modest improvements in wound healing were observed, significant enhancements were noted in oral ulcer recovery, with histological analyses indicating fully regenerated mucosal tissue. The study concludes that modifying viscosity enhances NAC retention, facilitating tissue regeneration. These findings support previous research on the beneficial effects of antioxidant application on damaged tissues, suggesting the potential of NAC hydrogels in improving wound care and oral ulcer treatment.

Stability Study of Parenteral N-Acetylcysteine, and Chemical Inhibition of Its Dimerization

Parenteral N-acetylcysteine has a wide variety of clinical applications, but its use can be limited by a poor chemical stability. We managed to control parenteral N-acetylcysteine stability, and to study the influence of additives on the decrease of N-acetylcysteine degradation. First, an HPLC-UV dosing method of N-acetylcysteine and its main degradation product, a dimer, was validated and the stability without additive was studied. Then, the influence of several additives (ascorbic acid, sodium edetate, tocopherol and zinc) and of temperature on N-acetylcysteine dimerization was evaluated. Finally, the influence of zinc gluconate at different concentrations (administrable to patients) was investigated. Zinc gluconate at 62.5 µg·mL-1 allows the stabilization of 25 mg·mL-1 N-acetylcysteine solution for at least 8 days when stored at 5 ± 3 °C.

N-acetylcysteine acts as a potent anti-inflammatory agent altering the eicosanoid profile in the development of simple steatosis and its progression to hepatitis.

We aimed to examine the influence of N-acetylcysteine (NAC) on the development of metabolic dysfunction-associated steatotic liver disease (MASLD) in rats with a specific focus on the eicosanoid pathway. The experiment was conducted on male Wistar rats fed a standard diet or a high-fat diet (HFD) for eight weeks. In the entire experiment, half of rats from both groups received intragastrically NAC solution prepared in normal saline. H + E staining was used for the histological assessment of liver tissue. The gas-liquid chromatography (GLC) technique was used for the assessment of the activity of n-3 and n-6 polyunsaturated fatty acid (PUFA) pathways and arachidonic acid concentration. ELISA and multiplex immunoassay kits were applied for the measurement of eicosanoid, cytokine, and chemokine levels. The Western blot technique was applied to determine the expression of proteins involved in the inflammation pathway. NAC decreased hepatic n-6 PUFA activity in all examined lipid pools and decreased the hepatic content of arachidonic acid as a pro-inflammatory precursor in each lipid pool, especially in the phospholipid fraction in rats with fatty lipid disease. NAC administration abolished 5-LOX expression, leading to a decrease in the content of pro-inflammatory leukotriene B4 and leukotriene C4. In rats with steatosis, NAC weakened NF-κB expression and raised Nrf-2 expression, inhibiting the synthesis of pro-inflammatory cytokines and chemokines. NAC treatment significantly rate-limited the progression of simple hepatic steatosis to hepatitis in a rat model of MASLD.

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

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

Comparison of Effectiveness of Nebulized N-Acetylcysteine Solution (Mucolytic Therapy), Nebulized Salbutamol and Nebulized Ipratropium Bromide In Treatment of Children with Acute Bronchiolitis

Background: Bronchiolitis is a viral mediated disease that results in acute inflammation in the lower respiratory tract. It occurs in infants and children under 2 years of age. The vast majority of infants’ experience at least 01 episode of bronchiolitis and 2-3% of all infants can be hospitalized for bronchiolitis in the 1st year. With an increasing rate having risen by an average of 1.8% annually in European country and a small percentage even need critical care. Children who are hospitalized for bronchiolitis currently only receive fluid replacement, additional oxygen and respiratory support. Bronchiolitis is most common motivator for hospital admissions in many nations. Respiratory syncytial virus (RSV) is most common virus causes bronchiolitis, and also causes infections during the winter months. Objective: To determine the comparison of effectiveness of nebulized N-acetylcysteine solution (mucolytic therapy), nebulized salbutamol and nebulized ipratropium bromide in treatment of children with acute bronchiolitis at a tertiary care hospital. Materials & Methods: All patients who fulfilled the inclusion criteria and visited to Baqai Medical University Hospital, Karachi from April 17, 2019 to October 16, 2019 were included in this Prospective Randomized Control Trial (lottery method). Informed consent was taken after explaining the procedure, risks and advantages of the study. Children from either gender having provisional diagnosis of acute bronchiolitis between 2 to 24 months of age were included and divided in three groups in our study. Each group obtained three treatments every day, introduced at intervals of eight hours for three days. Patients had been tested on admission, at 8 hours and every morning for severity of disease. For assessing improvement, scientific severity score turned into used to peer the effectiveness of nebulized N-acetylcysteine solution (mucolytic therapy), nebulized salbutamol and nebulized ipratropium bromide in bronchiolitis. All the collected data were entered into the proforma attached at the end and used electronically for research purpose. Results: 81 study cases of these, 44 (54.3%) were males while 37 (45.7%) were females. Our study cases mean age in Nebulized N-acetylcysteine was 9.4±6.3, in Nebulized Salbutamol and Ipratropium Bromide was 10.8±6.7 and 12.0±6.6 months, respectively. In group wise comparison of clinical severity score at baseline, 8, 24 and 72 hours, highly significant difference was found among the group at baseline, 8, 24 and 72 hours i.e., P ≤ (0.05) within the groups while on the other hand non-significant difference i.e., (0.633) was showed between the group at baseline among nebulized N-acetylcysteine, nebulized salbutamol and ipratropium bromide group respectively. Conclusion: In the lights of our findings, it is to be concluded that nebulized salbutamol was more effective in improvement of clinical severity score with shorter duration of hospital stay. Furthermore, it is to be concluded that there is a need to have further studies with larger sample size in different centers in Pakistan to validate the findings of current study. Keywords: N-acetylcysteine Solution, Nebulized Salbutamol, Nebulized Ipratropium Bromide, Acute Bronchiolitis

MRI Detection of Hepatic N-Acetylcysteine Uptake in Mice.

This proof-of-concept study looked at the feasibility of using a thiol–water proton exchange (i.e., CEST) MRI contrast to detect in vivo hepatic N-acetylcysteine (NAC) uptake. The feasibility of detecting NAC-induced glutathione (GSH) biosynthesis using CEST MRI was also investigated. The detectability of the GSH amide and NAC thiol CEST effect at B0 = 7 T was determined in phantom experiments and simulations. C57BL/6 mice were injected intravenously (IV) with 50 g L−1 NAC in PBS (pH 7) during MRI acquisition. The dynamic magnetisation transfer ratio (MTR) and partial Z-spectral data were generated from the acquisition of measurements of the upfield NAC thiol and downfield GSH amide CEST effects in the liver. The 1H-NMR spectroscopy on aqueous mouse liver extracts, post-NAC-injection, was performed to verify hepatic NAC uptake. The dynamic MTR and partial Z-spectral data revealed a significant attenuation of the mouse liver MR signal when a saturation pulse was applied at −2.7 ppm (i.e., NAC thiol proton resonance) after the IV injection of the NAC solution. The 1H-NMR data revealed the presence of hepatic NAC, which coincided strongly with the increased upfield MTR in the dynamic CEST data, providing strong evidence that hepatic NAC uptake was detected. However, this MTR enhancement was attributed to a combination of NAC thiol CEST and some other upfield MT-generating mechanism(s) to be identified in future studies. The detection of hepatic GSH via its amide CEST MRI contrast was inconclusive based on the current results.

Evaluation of Cellular and Systemic Toxicity of Dielectric Barrier Discharge Plasma-Treated N-Acetylcysteine as Potential Antimicrobial Catheter Lock Solution

Intravenous catheter-related bloodstream infections are a cause of remarkable problems. Catheter lock solutions are used to keep catheter patency and prevent catheter-related bloodstream infections. The leakage of catheter lock solution to the bloodstream raises toxicity concerns. Plasma-treated liquids carry the potential to act as catheter lock solutions by virtue of their strong antimicrobial effects. The present study investigates the tolerance of the proposed solution in vitro and in vivo. N-acetylcysteine (NAC) solution was treated with atmospheric-air DBD plasma and antimicrobial assays were performed. The cytotoxicity of the plasma-treated NAC solution was evaluated on an EA.hy926 cell line. Intravenous administration of plasma-treated NAC solution in different doses was given to Sprague Dawley rats. One week after infusion with plasma-treated NAC solution, first, the blood samples were collected, and then liver, kidney, tail vein, heart, and lung tissue samples were collected from euthanized rats for histopathological examination. The cytotoxicity of plasma-treated NAC solution depended on plasma treatment time, contact time, and cell number. A strong antimicrobial effect with no cytotoxicity of plasma-treated NAC solution was observed in endothelial cells. Based on blood tests and histopathological examination, no signs of systemic toxicity were observed that can be correlated to the plasma-treated-NAC solution. This solution has the potential to be used as a catheter lock solution with strong antimicrobial properties, keeping catheter patency.

Stability of N-Acetylcysteine 60 mg/mL in Extemporaneously Compounded Injectable Solutions.

N-Acetylcysteine (NAC) administered by the IV route is the current treatment of choice for acetaminophen overdose. However, the protocol approved by health authorities in most countries has a complex dosing regimen, which leads to dosage errors in one-third of cases. Therefore, the Canadian Antidote Guide in Acute Care Toxicology and individual poison centres have begun to recommend a simplified regimen using continuous IV infusion. Unfortunately, no study has demonstrated the stability of IV solutions of NAC at concentrations above 30 mg/mL or in solutions other than 5% dextrose. To evaluate the stability of solutions of NAC 60 mg/mL in 0.9% sodium chloride, 0.45% sodium chloride, or 5% dextrose, stored for up to 72 hours in polyvinyl chloride (PVC) bags at 25°C. Solutions of the desired concentration were prepared from a commercial solution of NAC 200 mg/mL, with dilution in 0.9% sodium chloride, 0.45% sodium chloride, or 5% dextrose, and were then stored at room temperature in PVC bags for up to 72 hours. At predetermined time points (0, 16, 24, 40, 48 and 72 h), samples were collected and analyzed using a stability-indicating high-performance liquid chromatography method. A solution was considered stable if it maintained at least 90.0% of its initial concentration. Particulate matter count was also evaluated to confirm chemical stability. Finally, organoleptic properties, such as odour and colour, were evaluated to assess the stability of the solutions. All solutions maintained at least 98.7% of their initial concentration. No obvious changes in odour or colour were observed. Moreover, particle counts remained acceptable throughout the study, according to the criteria specified in United States Pharmacopeia (USP) General Chapter <788>. NAC 60 mg/mL, diluted in 0.9% sodium chloride, 0.45% sodium chloride, or 5% dextrose and stored in PVC bags at 25°C, was chemically and physically stable for a period of at least 72 hours.

Comparing N-acetylcysteine with sodium thiosulfate for relieving symptoms caused by Lugol’s iodine chromoendoscopy: a randomized, double-blind trial

Lugol's iodine chromoendoscopy is an important method to detect esophageal squamous cell carcinoma. Sodium thiosulfate solution (STS) has been used to neutralize iodine after Lugol's chromoendoscopy; however, it is not available in many medical centers. The aim of the current study was to assess the efficacy of N-acetylcysteine solution (NAC) for relieving symptoms caused by Lugol's iodine chromoendoscopy. Patients were randomized to receive either STS or NAC after spraying Lugol's iodine solution on the esophagus. The neutralizing effects for residual iodine in the esophagus and gastric mucous pool were observed. The primary endpoint was the intensity of retrosternal pain and/or heartburn measured by a visual analog scale (VAS) score 30 minutes after chromoendoscopy. Secondary endpoints were the rate of patients with any adverse symptom, rate of moderate to severe retrosternal discomfort occurring, and heart rate variability between time points before and after chromoendoscopy. The neutralization rates for residual iodine between the NAC and STS groups were not significantly different (P > .999). The difference of median VAS scores between the NAC and STS groups 30 minutes after chromoendoscopy was .0 (P= .719; 95% confidence interval, .0-.0), and the 95% confidence interval higher limit was .0, which was less than our prespecified margin of .5, concluding an noninferiority of NAC with regard to STS. There was no significant difference between the 2 groups regarding the rate of patients with any adverse symptom, rate of moderate to severe retrosternal discomfort, or heart rate variability at 5 minutes or 30 minutes after chromoendoscopy. As a very easily accessible reagent in clinical circumstances, NAC can also alleviate mucosal irritation symptoms induced by Lugol's chromoendoscopy at similar efficacy as STS and can be routinely recommended. (Clinical trial registration number: NCT04764643.).

Application of thiol compounds to reduce acrylamide levels and increase antioxidant activity of French fries

The aim of this study was to examine the effects of thiol compounds, glutathione (GSH), cysteine (CYS) and N-acetylcysteine (NAC), on the color, antioxidant activity, total phenolic, ascorbic acid and acrylamide content of French fries which were fried at 180 °C for 6 min. Three different concentrations (0.5%, 1.0%, 2.0%) of each thiol compound were tested. Sulphite solution was used as a benchmark. According to the results, CYS and NAC solutions increased the antioxidant activity but GSH solution did not affect. The amount of ascorbic acid was highest in CYS (1.0%, 2.0%) and GSH (2.0%) treated samples. Although all pre-treatments decreased the acrylamide content, GSH2.0%, NAC2.0%, CYS (0.5%, 1.0%, 2.0%) provided 62–70% reduction. In addition, acrylamide showed a high correlation with L* (r=-0.82), a* (r=0.84), b* (r=0.77), ΔE (r=0.66), ascorbic acid (r=-0.79) and weak correlation with thiol content (r=-0.45). On the other hand, antioxidant activities had lack of correlation with acrylamide.

Bioinspired zwitterionic polyphosphoester modified porous silicon nanoparticles for efficient oral insulin delivery.

The intestinal epithelial and mucus barriers on the gastrointestinal tract limit the bioavailability of oral protein or peptide drugs. Therefore, efficient mucus permeability and cellular internalization are required properties for oral delivery systems. To overcome these two obstacles, porous silicon nanoparticles were modified with poly (pyridyl disulfide ethylene phosphate/sulfobetaine) polymers to make P(PyEP-g-SBm)n-AmPSiNPs (m = 0.1, 0.2, 0.3 and n = 10, 20, 30) nanoparticles (NPs). The insulin-loaded P(PyEP-g-SB)-AmPSiNPs showed favorable stability and good biocompatibility in vitro. The zwitterionic dodecyl sulfobetaine (SB) coated nanoparticles improved the mucus permeability. P(PyEP-g-SBm)20 with the optimal conjugated ratio (m = 0.3) of SB units was determined by evaluating the mucus diffusion rate of NPs. The cellular uptake of P(PyEP-g-SB0.3)n-AmPSiNPs (n = 10, 20, 30) was much higher than AmPSiNPs in the presence of inhibitors (N-acetylcysteine solution and sodium chlorate) (p < 0.01) due to the enhanced charge shielding effect of P(PyEP-g-SB) modification. The P(PyEP-g-SB0.3)20-AmPSiNPs showed about 1.4-1.7 fold increase in the apparent permeability of insulin across Caco-2/HT-29-MTX cell monolayers, compared to AmPSiNPs (p < 0.01). Finally, the in vivo study showed that insulin-loaded P(PyEP-g-SB0.3)20-AmPSiNPs generated 20% reduction of the blood glucose level with an 2-fold increase in oral bioavailability. These suggested that zwitterionic polyphosphoester modified porous silicon nanoparticles, which were of enhanced mucus permeability and cellular internalization, represent a promising carrier for oral delivery of peptide and protein.

The effect of N-acetyl cysteine on biofilm layers in an experimental model of chronic otitis media.

SUMMARYObjectıveThe aim of this study was to investigate the efficacy of N-acetylcysteine (NAC) on biofilm layers and on the course of disease in chronic otitis media.MethodsTwenty-five rats that were induced with chronic otitis media (COM) were separated into three groups. In Group 1 (N = 18), 0.2% ciprofloxacin + 0.1% dexamethasone sodium phosphate + 0.5 mg/ml NAC solution was locally injected to the right ear of the rats; in Group 2, (N=18) 0.2% ciprofloxacin + 0.1% dexamethasone sodium phosphate was locally injected to the left ear of the rats. No treatment was applied to either ear of rats in Group 3 (N = 5). Histopathological and scanning electron microscope (SEM) evaluations were performed in all groups.ResultsSEM revealed biofilm formation in all COM induced groups. No significant difference was seen between groups 1 and 2 in terms of suppuration levels, fibrosis, inner ear involvement, infection staging and biofilm formation (p > 0.05).ConclusıonsIn this study, while histopathological and SEM evaluation revealed no effect of 0.5 mg/ml NAC on the biofilm layer in COM-induced rats, further studies with NAC at different concentrations are still needed on different types of experimental animals.

Inactivation of biofilms in endotracheal tube by cold atmospheric plasma treatment for control and prevention of ventilator‐associated pneumonia

AbstractVentilator‐associated pneumonia (VAP) is a type of hospital‐acquired infection with high mortality and morbidity rates that is seen in critically ill patients who are connected to mechanical ventilators in intensive care units. Conventional infection control measures may remain insufficient for control and prevention of VAP. In the present study, biofilms of most common pathogens, which are responsible for VAP, namely Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, and Candida albicans, were grown in the lumen of endotracheal tubes (ETs) under low shear to mimic the biofilm formation in clinical settings using the drip flow reactor system. Antibiofilm efficacies of two different plasma treatment methods were tested on the biofilms that were grown in ETs. In the first method, deionized water (DIW), phosphate‐buffered saline (PBS) solution, and N‐acetylcysteine (NAC) solution were treated with air dielectric barrier discharge (DBD) plasma and then nebulized on the biofilms. In the second method, air plasma afterglow (APA), which was generated using a DBD jet electrode, was flown through the lumen of ETs. Effects of two different plasma treatment methods on biofilms were evaluated using colony‐counting and XTT assays. The quantity of extracellular polymeric substance (EPS) was evaluated with the safranin assay. Scanning electron microscopy (SEM) was used to visualize the effect of various plasma treatment methods on biofilms. Cytotoxic effects of two different plasma treatment methods were tested on the human tracheal epithelial cell line. Our results suggest that the nebulized plasma‐treated NAC solution had a superior antibiofilm effect as compared with DIW and PBS. Two different plasma treatment methods used effectively inactivated biofilms and significantly reduced the quantity of EPS without a significant damage to the human tracheal epithelial cell line. Furthermore, SEM images showed the inactivation of microbial cells mainly through membrane damage.

N-acetylcysteine alleviates liver injury by suppressing macrophage-mediated inflammatory response post microwave ablation

ObjectTo investigate N-acetyl-cysteine (NAC) would able to alleviate liver injury and systemic inflammatory response caused by microwave ablation (MWA) in rats. Materials and methodsMale Sprague-Dawley rats weighing 150–200 g were randomly divided into sham group (only anesthesia and laparotomy except MWA but with intraperitoneal PBS or NAC solution injection according to different situations), control group (intraperitoneal PBS injection for comparation 2 h prior to MWA), and NAC-treated group (intraperitoneal N-acetyl-cysteine (300 mg/kg) injection 2 h prior to MWA). Experimental rats were sacrificed at 4 h following operation in line with the liver injury severity curve. Liver tissue and serum samples were collected for determination of pathology, apoptosis, macrophages contents and protein expression. ResultsThe elevated serum level of liver enzymes, Myeloperoxidase (MPO) and inflammatory factors (TNF-α and CXCL1) in MWA-treated rats revealed injurious and pro- inflammatory effect of MVA. Macrophages aggregation was detected in MWA exposure rats similarly. and NAC pre-conditioning mitigate liver damage and hepatocyte apoptosis, besides macrophages accumulation and following inflammatory response in liver tissue. ConclusionOur results demonstrated that N-acetyl-cysteine application alleviate macrophages aggregation and inflammatory response in liver suffering microwave ablation, and mitigating liver injury and cell apoptosis.

Intratympanic application of poloxamer 407 hydrogels results in sustained N-acetylcysteine delivery to the inner ear

N-acetylcysteine is a thiol-containing antioxidant, which has shown otoprotective effects in in vitro as well as in vivo models of cisplatin-induced hearing loss. Systemic administration of antioxidants, however, is associated with the major potential drawback of interference with the tumoricidal effect of cisplatin. This therapeutic limitation can be overcome by local intratympanic injection of the antioxidant N-acetylcysteine, which results in very restricted systemic uptake of the drug, whilst intracochlear drug levels are substantially higher. Furthermore, osmolality and pH properties of formulations for intratympanic injection need to be controlled, as they impact the fraction of drug crossing the barriers of the inner ear and could potentially damage middle and inner ear structures. This study focused on (i) the evaluation of concentration–time profiles of N-acetylcysteine in perilymph, cerebrospinal fluid and plasma after intratympanic administration, (ii) the influence of the dosage form, i.e. a thermoreversible poloxamer 407 hydrogel versus a solution, on N-acetylcysteine pharmacokinetics, and (iii) the development of a pH- and osmolality-adjusted formulation for intratympanic N-acetylcysteine delivery.49 female albino guinea pigs were randomized into two treatment groups, receiving either a single intratympanic injection of a 4% N-acetylcysteine poloxamer 407 hydrogel or a 4% N-acetylcysteine solution. 8 animals served as untreated controls. N-acetylcysteine levels in perilymph, cerebrospinal fluid and plasma were monitored over a period of 24 h. Samples were taken at 1, 3, 6, 12 and 24 h (poloxamer 407 hydrogel group) and 1, 6 and 24 h (solution group) post injection, and analysed by high performance liquid chromatography-tandem mass spectrometry. Intratympanic application of the 4% N-acetylcysteine poloxamer 407 hydrogel resulted in a 4-fold larger perilymph area under the concentration–time curve (0–24 h) than topical administration of the equally concentrated N-acetylcysteine solution but in similar plasma N-acetylcysteine levels. N-acetylcysteine concentrations in the cerebrospinal fluid were below the level of detection (5 ng/ml) in both treatment groups. N-acetylcysteine-containing formulations applied to the middle ear were isohydric and osmolality was reduced by up to 200 mosmol/kg compared to equally concentrated formulations used in previous studies.In summary, we were able to demonstrate that the intratympanic injection of thermoreversible poloxamer 407 hydrogels increases and sustains N-acetylcysteine delivery to the inner ear. Given the low plasma N-acetylcysteine levels after topical application and the physiological pH and osmolality of the hydrogel, the risk of compromising the antineoplastic effects of cisplatin therapy and of local side effects is minimal.

Vitachelox: Protection of the Skin Against Blue Light-Induced Protein Carbonylation

Protein carbonylation (PC) is a marker of reactive oxygen species-mediated alterations induced by external stimuli such as UV and blue light irradiation. In this study, we investigated the protective effect of Vitachelox®, a mixture of three standardized natural extracts rich in polyphenols, against PC induced by blue light irradiation in human keratinocytes. We tested eight experimental conditions, including Vitachelox® 0.01% and 0.005% w/v, used for 6 or 24 h before irradiation, and a solution of N-acetylcysteine (NAC) as positive control of protection. PC was evaluated by fluorescence microscopy in situ and by absolute quantification (Carbonyl Score) upon protein extraction and separation. Both the in situ visualization study and the carbonyl score showed a considerable increase in protein oxidative damage upon blue light irradiation, and a decrease in PC in the presence of Vitachelox®. In particular, Vitachelox® 0.005% showed superior results compared to NAC in terms of carbonyl score and protein quality, and it was estimated to exert a protective action against blue-light irradiation ranging from 72% (24 h) to 82% (6 h). The protective antioxidant effect of Vitachelox®, together with the anti-inflammatory and anti-microbial properties previously reported, make this natural active ingredient a valuable tool in the maintenance of healthy skin.

Mo1040 RETENTION OF N-ACETYLCYSTEINE CAPSULE IN PATIENTS UNDERGOING UPPER GASTROINTESTINAL ENDOSCOPY

N-acetylcysteine (NAC) is a mucolytic agent, and NAC solution has been used to improve visibility during upper gastrointestinal (UGI) endoscopy. On the other hand, NAC capsule may leave a residue in the esophagus and interfere clear mucosal visualization (Figure 1,2). This study aimed to assess the frequency of esophageal retention of residue from NAC capsule during UGI endoscopy.

Escherichia coli cellular responses to exposure to atmospheric-pressure dielectric barrier discharge plasma-treated N-acetylcysteine solution.

To understand the underlying cellular mechanisms during inactivation of Escherichia coli in response to antimicrobial solution of nonthermal plasma-activated N-acetylcysteine (NAC). The recommended techniques were used to demonstrate E.coli cellular and transcriptomic changes caused associated with peroxynitrite and compared with plasma-treated NAC solution. The findings demonstrate that E.coli cells respond to plasma-treated NAC and undergo severe oxidative and nitrosative stress, and leading to stress-induced damages to different components of bacterial cells, which includes loss of membrane potential, formation of oxidized glutathione (GSSG), formation of nitrotyrosine (a known marker of nitrosative stress), DNA damage, and generated a prominent pool of peroxynitrite. Reverse-transcriptase (RT)-polymerase chain reaction analysis of reactive nitrogen species (RNS) responsive genes indicated their differential expressions. For the first time, we report that the plasma-treated NAC solution activates predominantly nitrosative stress-responsive genes in E.coli and is responsible for cell death. The reactive species generated in solutions by nonthermal plasma treatment depends on the type of solution or solvent used. The plasma-treated NAC solution rapidly inactivates E.coli, mostly involving highly RNS generated in NAC solution, and has high potential as disinfectant.

Effects of chitosan and chitosan N-acetylcysteine solutions on conjunctival epithelial cells

# Aim of the study Chitosan, a partially deacetylated polysaccharide derived from chitin, and chitosan-N-acetylcysteine (C-NAC), a thiolated chitosan, both show enhanced retention times on the ocular surface when compared to other polymers commonly used in eye drops. To evaluate these compounds as adjuvants for ocular drug delivery or uptake of topically administered conjunctival vaccines, biochemical characteristics of both polymers were investigated in vitro and in vivo. # Methods Human conjunctival epithelial (HCjE) cells were used to investigate biocompatibility of buffered chitosan and C-NAC containing formulations. Cellular uptake was studied using fluorescein-isothiocyanate (FITC)-labelled polymers. Transepithelial electrical resistance (TEER) measurements were performed to determine effects of chitosan on tight junctions of stratified HCjE cells in vitro. In vivo uptake of topically applied chitosan into conjunctival epithelial cells was investigated in guinea pigs. # Results Minimal effects on cell viability were seen with both compounds after application for 30 min in a concentration of 0.1%. In vitro uptake into HCjE cells was only observed with the chitosan containing solution. An effect on tight junctions was demonstrated by significantly (P < .05) decreasing TEER levels 60 min after incubation with chitosan. In vivo, FITC-labelled chitosan was detected within guinea pig conjunctival epithelial cells 120 min after topical administration. No adverse effects were observed. # Conclusions Results demonstrated that chitosan is taken up into conjunctival epithelial cells in vitro and in vivo, therefore fulfilling some of the requirements of an adjuvant for conjunctival mucosal vaccines. C-NAC is also well tolerated but not taken up by cells, making it a good candidate for ocular formulations supposed to persist on the ocular surface for an extended period of time.

К вопросу диагностики диабетической макроангиопатии нижних конечностей у пациентов с сахарным диабетом 2-го типа и способы коррекции выявленных нарушений

Diabetes mellitus remains one of the most pressing problems in the 21st century. The research objective was to study the level of glycotoxins and oxidation-reduction potential of a serum/cell at the complicated and uncomplicated course of diabetes mellitus type 2 was and find the ways to correct the disorder. Materials and methods. There were three groups of patients aged from 55 up to 70 years, a total of 80 people. The main group (group No. 3) was presented by 40 men suffering from a diabetes mellitus type 2 with a macrovascular disease of the lower extremities. Depending on the chosen remedy and the carried-out therapy, patients of the first group were sectioned into subgroups on 20 people, in the 2nd subgroup additionally N-acetylcysteine solution was introduced in a daily dose of 600 mg once, intravenously, within 7 days. Definition of the studied indicators was made by HPLS methods, prior to therapy, for the third and seventh day. Results. Obtained data confirm activation of polyol pathway of glucose disintegration. Antioxidant potential of the serum and cells decreases. Using N-acetylcysteini in complex therapy reduces implications of carbonyl and oxidative stresses, due to multiple decrease of the final products of glycation. Conclusions. When identifying the presented indicators in patients with diabetic macroangiopathy of the lower extremities, the administration of N-acetylcysteine, intravenously in a daily dose of 600 mg (7 days course) is recommended.