Butylated hydroxytoluene and N-acetylcysteine attenuates tumor necrosis factor-alpha (TNF-alpha) secretion and TNF-alpha mRNA expression in alveolar macrophages from human lung transplant recipients in vitro

Absorption of N-acetylcysteine in Healthy and Mycoplasma gallisepticum-Infected Chickens

N-acetylcysteine (NAC) is widely used as a mucolytic agent in cases with inflammation of the lungs. NAC is applied in poultry with aflatoxin B1 intoxication as an antioxidant, but its pharmacokinetics are not known. The present study was conducted to characterize the population pharmacokinetics of orally administered NAC in broilers. It included 32 chickens, divided into four groups, treated with NAC at a dose rate of 100 mg/kg/day mixed with the feed: healthy broilers (n = 6); chickens infected with Mycoplasma gallisepticum (n = 10); healthy broilers (n = 6); and diseased chickens (n = 10) treated with NAC and doxycycline (via drinking water, 20 mg/kg body weight (b.w.)). Plasma concentrations were analyzed by Liquid Chromatography –Mass Spectrometry (MS)/MS. NAC was absorbed after oral administration in all four groups of chickens. In healthy chickens treated solely with NAC, maximum plasma concentrations of 2.26 ± 0.91 µg mL⁻¹ were achieved at 2.47 ± 0.45 h after dosing. The value of absorption half-life was 1.04 ± 0.53 h. The population pharmacokinetic analysis showed that dose adjustment of NAC is not required in M. gallisepticum-infected broilers or when it is combined with doxycycline.

Comparative Metabolomics Reveals the Microenvironment of Common T-Helper Cells and Differential Immune Cells Linked to Unique Periapical Lesions

Periapical abscesses, radicular cysts, and periapical granulomas are the most frequently identified pathological lesions in the alveolar bone. While little is known about the initiation and progression of these conditions, the metabolic environment and the related immunological behaviors were examined for the first time to model the development of each pathological condition. Metabolites were extracted from each lesion and profiled using gas chromatography-mass spectrometry in comparison with healthy pulp tissue. The metabolites were clustered and linked to their related immune cell fractions. Clusters I and J in the periapical abscess upregulated the expression of MMP-9, IL-8, CYP4F3, and VEGF, while clusters L and M were related to lipophagy and apoptosis in radicular cyst, and cluster P in periapical granuloma, which contains L-(+)-lactic acid and ethylene glycol, was related to granuloma formation. Oleic acid, 17-octadecynoic acid, 1-nonadecene, and L-(+)-lactic acid were significantly the highest unique metabolites in healthy pulp tissue, periapical abscess, radicular cyst, and periapical granuloma, respectively. The correlated enriched metabolic pathways were identified, and the related active genes were predicted. Glutamatergic synapse (16–20),-hydroxyeicosatetraenoic acids, lipophagy, and retinoid X receptor coupled with vitamin D receptor were the most significantly enriched pathways in healthy control, abscess, cyst, and granuloma, respectively. Compared with the healthy control, significant upregulation in the gene expression of CYP4F3, VEGF, IL-8, TLR2 (P < 0.0001), and MMP-9 (P < 0.001) was found in the abscesses. While IL-12A was significantly upregulated in cysts (P < 0.01), IL-17A represents the highest significantly upregulated gene in granulomas (P < 0.0001). From the predicted active genes, CIBERSORT suggested the presence of natural killer cells, dendritic cells, pro-inflammatory M1 macrophages, and anti-inflammatory M2 macrophages in different proportions. In addition, the single nucleotide polymorphisms related to IL-10, IL-12A, and IL-17D genes were shown to be associated with periapical lesions and other oral lesions. Collectively, the unique metabolism and related immune response shape up an environment that initiates and maintains the existence and progression of these oral lesions, suggesting an important role in diagnosis and effective targeted therapy.

Nutritional Requirements of Lung Transplant Recipients: Challenges and Considerations

An optimal nutritional status is associated with better post-transplant outcomes and survival. Post-lung transplant nutrition management is however particularly challenging as lung recipients represent a very heterogeneous group of patients in terms of age, underlying diseases, weight status and presence of comorbidities. Furthermore, the post-transplant period encompasses several stages characterized by physiological and pathophysiological changes that affect nutritional status of patients and necessitate tailored nutrition management. We provide an overview of the current state of knowledge regarding nutritional requirements in the post-lung transplant period from the immediate post-operative phase to long-term follow-up. In the immediate post-transplantation phase, the high doses of immunosuppressants and corticosteroids, the goal of maintaining hemodynamic stability, the presence of a catabolic state, and the wound healing process increase nutritional demands and lead to metabolic perturbations that necessitate nutritional interventions. As time from transplantation increases, complications such as obesity, osteoporosis, cancer, diabetes, and kidney disease, may develop and require adjustments to nutrition management. Until specific nutritional guidelines for lung recipients are elaborated, recommendations regarding nutrient requirements are formulated to provide guidance for clinicians caring for these patients. Finally, the management of recipients with special considerations is also briefly addressed.

Effect of N-acetylcysteine on acute allograft rejection after rat lung transplantation

BACKGROUND

N-Acetylcysteine (NAC) attenuates ischemia-reperfusion injury after lung transplantation in animal models. The purpose of this study is to evaluate a protective effect of NAC against acute lung rejection.

METHODS

Rat single-lung transplantation was performed in four groups (n = 7 per group). In NAC groups, donors and recipients received NAC 150 mg/kg per day intraperitoneally before transplantation and recipients thereafter until euthanasia. Control groups (CON) received 0.5 mL of 0.9% saline solution intraperitoneally instead of NAC. Animals were euthanized on day 1 (CON1, NAC1) or day 5 (CON5, NAC5) after transplantation. Lung tissue was assessed by histology, immunohistochemistry for CD68+/CD163+ macrophages and CD3+ T cells, immunofluorescence for interleukin 4 and interleukin 12, concentration of reduced glutathione, and activated nuclear factor-kappa B.

RESULTS

CD68+ macrophages in CON5 accumulated significantly compared with NAC5 grafts (p < 0.001). No significant difference was observed for CD163+ macrophages on day 5. T cells were significantly more frequent in NAC1 (p < 0.001), but significantly less in NAC5 (p < 0.001) compared with control groups, respectively. Interleukin 4 and interleukin 12 expression did not differ between groups. Treatment with NAC significantly influenced glutathione levels (p = 0.019) and reduced nuclear factor-kappa B activation (p = 0.034) in transplanted lungs.

CONCLUSIONS

N-Acetylcysteine has the potential to attenuate acute pulmonary rejection by reduction of macrophage and T-cell infiltration, which is intimately linked to a reduced action of the nuclear factor-kappa B proinflammatory signaling pathway. In view of these observations, NAC should be considered a promising substance that could play a role in strategies for the prevention of acute rejection.

Treatment for sulfur mustard lung injuries; new therapeutic approaches from acute to chronic phase

Objective

Sulfur mustard (SM) is one of the major potent chemical warfare and attractive weapons for terrorists. It has caused deaths to hundreds of thousands of victims in World War I and more recently during the Iran-Iraq war (1980–1988). It has ability to develop severe acute and chronic damage to the respiratory tract, eyes and skin. Understanding the acute and chronic biologic consequences of SM exposure may be quite essential for developing efficient prophylactic/therapeutic measures. One of the systems majorly affected by SM is the respiratory tract that numerous clinical studies have detailed processes of injury, diagnosis and treatments of lung. The low mortality rate has been contributed to high prevalence of victims and high lifetime morbidity burden. However, there are no curative modalities available in such patients. In this review, we collected and discussed the related articles on the preventive and therapeutic approaches to SM-induced respiratory injury and summarized what is currently known about the management and therapeutic strategies of acute and long-term consequences of SM lung injuries.

Method

This review was done by reviewing all papers found by searching following key words sulfur mustard; lung; chronic; acute; COPD; treatment.

Results

Mustard lung has an ongoing pathological process and is active disorder even years after exposure to SM. Different drug classes have been studied, nevertheless there are no curative modalities for mustard lung.

Conclusion

Complementary studies on one hand regarding pharmacokinetic of drugs and molecular investigations are mandatory to obtain more effective treatments.

The role of prophylactic ibuprofen and N-acetylcysteine on the level of cytokines in periapical exudates and the post-treatment pain

Background

Periapical lesions are inflammatory diseases that result in periapical bone destruction because of host defensive–microbial disturbances.

Objective

To evaluate the role of prophylactic ibuprofen and N-acetylcysteine (NAC) on the levels of tumor necrosis factor alpha (TNF- α), interleukin- 6(IL-6) and IL-17 and post-treatment pain level in chronic periapical lesions.

Materials and methods

Eighty patients with chronic apical lesions less than 1 cm were randomly assigned to receive NAC tablets (400 mg), ibuprofen tablets (400 mg), NAC (400 mg)/ibuprofen (200 mg) combination and placebo 90 minutes prior to sampling. Periapical exudates were collected from root canals. TNF- α, IL-6 and IL-17 levels were determined by ELISA and post-treatment pain was assessed using a visual analog scale (VAS).

Results

There was a significant difference in IL-6 level between ibuprofen group and placebo (p = 0.019). Significant difference in IL-17 level was observed between NAC/ibuprofen combination group and placebo (p = 0.043). Four hours after treatment, a significant difference was observed in VAS pain score between ibuprofen group and placebo (p = 0.017). Eight hours post-treatment, VAS pain score for NAC group was statistically lower than placebo group (p = 0.033). After 12 hours VAS pain score showed a significant decrease in NAC group compared to placebo (p = 0.049).

Conclusion

The prophylactic ibuprofen and NAC failed to clearly reflect their effect on cytokines levels in exudates of chronic periapical lesions. On the other hand it seems that NAC can be a substitute for ibuprofen in the management of post endodontic pain.

Analysis of the effects of iron and vitamin C co-supplementation on oxidative damage, antioxidant response and inflammation in THP-1 macrophages

OBJECTIVES

The aims of the study were to test the susceptibility of THP-1 macrophages to develop oxidative stress and to deploy antioxidant defense mechanisms that insure the balance between the pro- and antioxidant molecules.

DESIGN AND METHODS

Differentiated THP-1 were incubated in the presence or absence of iron-ascorbate (Fe/As) (100/1000μM) and the antioxidants Trolox, BHT, α-Tocopherol and NAC.

RESULTS

Fe/As promoted the production of lipid peroxidation as reflected by the formation of malondialdehyde and H(2)O(2) along with reduced PUFA levels and elevated glutathione disulfide/total glutathione ratio, a reliable index of cellular redox status. THP-1 macrophages developed an increase in cytoplasmic SOD activity due in part to high cytoplasmic SOD1. On the other hand, a decline was noted in mRNA and protein of extra-cellular SOD3, as well as the activity of GSH-peroxidase, GSH-transferase and ATOX-1 expression.

CONCLUSIONS

Macrophages activated under conditions of oxidative stress do not adequately deploy a powerful endogenous antioxidant response, a situation that can lead to an enhanced inflammatory response.

N-acetylcysteine attenuates lung ischemia-reperfusion injury after lung transplantation

BACKGROUND

Early acute graft dysfunction continues to be a problem after lung transplantation and results in significant postoperative morbidity and mortality. This study assessed the protective effect of N-acetylcysteine (NAC) on posttransplant lung ischemia-reperfusion injury.

METHODS

Rat single-lung transplantation was performed in two experimental groups (n = 5) after 18 hours of cold (4 degrees C) ischemia. Group I was the ischemic control (IC) group. In group II (NAC), donor and recipient animals were treated with an intraperitoneal injection of 150 mg/kg NAC 15 minutes before harvest, and recipient animals were treated again before reperfusion. After 2 hours of reperfusion, oxygenation was measured. Lung tissue was assessed for lipid peroxidation, neutrophil infiltration, and reduced glutathione level. Peak airway pressure was recorded throughout the reperfusion period.

RESULTS

Rats treated with NAC showed significantly better oxygenation (184.5 +/- 83.3 mm Hg versus 67.3 +/- 16.4 mm Hg, p = 0.016) and reduced lipid peroxidation (7.34 +/- 1.9 micromol/g versus 17.46 +/- 10.6 micromol/g, p = 0.016). Lung tissue reduced glutathione levels were 6.8 +/- 0.9 microM in the IC group and 20.6 +/- 2.4 microM in the NAC group (p = 0.004). Peak airway pressure at the end of the reperfusion period was 14.4 +/- 1.6 cm H2O in the NAC group, and 19.2 +/- 2.2 cm H2O in the IC group (p = 0.008). Myeloperoxidase activity and the ratio of wet-to-dry weight did not differ between the groups.

CONCLUSIONS

In this model, exogenously administered NAC effectively protected the lungs from reperfusion injury after prolonged ischemia.

Influx of macrophages into livers of rats treated with hepatotoxicants (thioacetamide, allyl alcohol, D-galactosamine) induces expression of HSP25

Treatment of rats with a single dose of thioacetamide (TAA) provokes centrilobular inflammation and a significant expression of heat shock protein HSP25 in hepatocytes surrounding the area of inflammation. The HSP25 accumulation in hepatocytes adjacent to inflammatory regions was confirmed by identification of positive hepatocytes concentrated at periportal areas after treatment of rats with allyl alcohol (AA) or distributed diffusely throughout liver lobule after treatment with D-galactosamine (D-gal). In our model of TAA-treated rats the use of the anti-inflammatory drug-indomethacin, and the redox-regulating drug-N-acetylcysteine (NAC), significantly attenuated TAA-induced HSP25 expression and evoked morphological changes of recruited ED1+ macrophages. Treatment of rats with gadolinium chloride (GdCl(3)) decreased considerably the number of Kupffer cells (ED2+ macrophages) without affecting significantly the number and morphology of ED1+ macrophages as well as the expression pattern of TAA-induced HSP25. Our data shows for the first time that ED1+ macrophages recruited into the liver by treatment with TAA play a significant role in HSP25 induction in hepatocytes.

Induction of tumor necrosis factor-alpha by UVB: a role for reactive oxygen intermediates and eicosanoids

UVB irradiation induces nuclear factor-kappaB (NF-kappaB) activation, tumor necrosis factor-alpha (TNF-alpha) expression and reactive oxygen intermediates (ROI) in keratinocytes. We investigated whether ROI play a role in UVB-induced TNF-alpha mRNA expression. The antioxidants N-acetyl cysteine, NAC, epigallocathin gallate, EGCG, butylated hydroxyanisole (BHA) and vitamin C could reduce UVB-induced TNF-alpha mRNA levels to various degrees; vitamin E (alpha-tocopherol) had no effect. BHA was the most potent inhibitor. The oxidant tertiary butylated hydroperoxide could effectively induce TNF-alpha mRNA expression. Nordihydroguaiaretic acid (NDGA) and MK-886, inhibitors of lipoxygenase (LOX), and indometacin and quinacrine, inhibitors of cyclooxygenase (COX) and phospholipase A2, respectively, could also reduce UVB-induced TNF-alpha mRNA expression. Inhibition by NDGA was in concordance with the results for BHA. NDGA, indometacin, quinacrine and BHA could also effectively inhibit the inhibitor of NF-kappaB degradation, thereby maintaining NF-kappaB inactivity. In conclusion, we show that ROI are implicated in the induction of TNF-alpha mRNA by UVB and that not all antioxidants are equally effective inhibitors. COX products and more importantly LOX products, which themselves are products of an oxidative metabolism, are the main ROI implicated in this induction of TNF-alpha expression by UVB probably via activation of NF-kappaB.

Inhibitory effects of N-acetylcysteine on scavenger receptor class A expression in human macrophages

OBJECTIVE

The formation of foam cells from monocyte-derived macrophages involves the uptake of modified lipoproteins by scavenger receptors. Antioxidants inhibit lipoprotein oxidation and may also modulate gene expression. We investigated the effect of the antioxidant N-acetylcysteine on the expression of the class A scavenger receptor (SR-A) types I and II in human macrophages.

DESIGN

Monocytes and macrophages from healthy blood donors and plaque-derived macrophages from patients undergoing carotid endarterectomy were used for experiments. SR-A mRNA was analysed with quantitative and semiquantitative reverse transcription-polymerase chain reaction, and ligand binding and uptake were assessed with 125I-labelled acetylated low-density lipoprotein (LDL).

RESULTS

Incubation of monocytes and monocyte-derived macrophages with N-acetylcysteine decreased both SR-A I and II mRNA expression. N-Acetylcysteine also reduced SR-A mRNA in lesion-derived cells. Binding and uptake of 125I-acetylated LDL was decreased after brief incubation with N-acetylcysteine. After longer periods of incubation with N-acetylcysteine we observed an increased degradation of lipoproteins.

CONCLUSIONS

Our results imply that N-acetylcysteine leads to a decrease in SR-A mRNA and initially also to an attenuated uptake of modified lipoproteins. This adds more to the knowledge about the cellular actions of this drug.

N-acetylcysteine inhibits in vivo nitric oxide production by inducible nitric oxide synthase

This in vivo study evaluates the effect of N-acetylcysteine (NAC) administration on nitric oxide (NO) production by the inducible form of nitric oxide synthase (iNOS). NO production was induced in the rat by the ip administration of 2 mg/100 g lipopolysaccharide (LPS). This treatment caused: (1) a decrease in body temperature within 90 min, followed by a slow return to normal levels; (2) an increase in plasma levels of urea, nitrite/nitrate, and citrulline; (3) the appearance in blood of nitrosyl-hemoglobin (NO-Hb) and in liver of dinitrosyl-iron-dithiolate complexes (DNIC); and (4) increased expression of iNOS mRNA in peripheral blood mononuclear cells (PBMC). Rat treatment with 15 mg/100 g NAC ip, 30 min before LPS, resulted in a significant decrease in blood NO-Hb levels, plasma nitrite/nitrate and citrulline concentrations, and liver DNIC complexes. PBMC also showed a decreased expression of iNOS mRNA. NAC pretreatment did not modify the increased levels of plasma urea or the hypothermic effect induced by the endotoxin. The administration of NAC following LPS intoxication (15 min prior to sacrifice) did not affect NO-Hb levels. These results demonstrate that NAC administration can modulate the massive NO production induced by LPS. This can be attributed mostly to the inhibitory effect of NAC on one of the events leading to iNOS protein expression. This hypothesis is also supported by the lack of effect of late NAC administration.

Effects of antioxidants apocynin and the natural water-soluble antioxidant from spinach on cellular damage induced by lipopolysaccaride in the rat

Oxidative damage plays a key role in septic shock induced by the endotoxin lipopolysaccaride (LPS) by enhancing the formation of reactive oxygen species such as superoxide anion radicals, peroxides, and their secondary product, malondialdehyde, especially in the liver. In this study, histopathologic changes in several organs were compared among groups of male Wistar rats that had been injected with LPS following prophylactic pretreatment with either of 2 antioxidants, a group that had been injected with LPS without pretreatment with antioxidants, an untreated control group, and groups that had been injected with either of the 2 antioxidants only. The antioxidants used were a water-soluble natural antioxidant from spinach (NAO) and the NADPH oxidase inhibitor apocynin. Hematoxylin-and-eosin-stained slides were prepared, and lesions were semiquantitatively scored. Exposure to LPS alone was associated with multifocal hepatocellular necrosis and acute inflammation, thymic and splenic lymphoid necrosis, ocular retinal hemorrhage and acute endophthalmitis, adrenal medullary vacuolation and necrosis and acute inflammation, and decreased adrenal cortical cytoplasmic vacuolation (consistent with depletion of steroidal hormone contents). Results indicated that pretreatment with both antioxidants for 8 days reduced, in some organs, the necrotic and inflammatory changes associated with the LPS challenge. These findings suggest a potential therapeutic application for these antioxidants in clinical sepsis.