Ameliorative effects of dimetylthiourea and N-acetylcysteine on nanoparticles induced cyto-genotoxicity in human lung cancer cells-A549

Synergistic protective effects of lycopene and N-acetylcysteine against cisplatin-induced hepatorenal toxicity in rats

Cisplatin (CP) is one of the most frequently used chemotherapy agents. The objective of this design was to determine the ameliorative effect of lycopene (LP) and/or N-acetylcysteine (NAC) in rats with hepatic and renal toxicity induced by CP. Rats were divided randomly into 7 groups (7 rats/group): control vehicle group (saline only), the LP group (10 mg/kg, orally), the NAC group (150 mg/kg, orally), the CP group (7.5 mg/kg, IP on day 27), the LP-CP group, the NAC-CP group, and the LP-NAC-CP group. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (APK), and levels of urea, creatinine, and lipids (cholesterol, triglycerides, and low-density lipoprotein-cholesterol) increased after CP injection in the serum. Moreover, CP decreased levels of protein, albumin, and HDL cholesterol. Meanwhile, malondialdehyde significantly increased with a decrease in reduced glutathione, superoxide dismutase, and catalase in the liver and kidney tissues. CP also induced some pathological lesions and increased the expression of caspase-3 in the liver and kidney tissues. Administration of LP and NAC alone or in combinations ameliorated hepatorenal toxicity and apoptosis induced by CP.

Genotoxicity Evaluation of Titanium Dioxide Nanoparticles In Vitro: a Systematic Review of the Literature and Meta-analysis

With the wide use of titanium dioxide nanoparticles (TiO₂-NPs), the genotoxicity of TiO₂-NPs, which is a factor for safety assessment, has attracted people's attention. However, their genotoxic effects in vitro remain controversial due to inconsistent reports. Therefore, a systematic review was conducted followed by a meta-analysis to reveal whether TiO₂-NPs cause genotoxicity in vitro. A total of 59 studies were identified in this review through exhaustive database retrieval and exclusion. Meta-analysis results were presented based on different evaluation methods. The results showed that TiO₂-NP exposure considerably increased the percentage of DNA in tail and olive tail moment in comet assay. Gene mutation assay revealed that TiO₂-NPs could also induce gene mutation. However, TiO₂-NP exposure had no effect on micronucleus (MN) formation in the MN assay. Subgroup analysis showed that normal cells were more vulnerable to toxicity induced by TiO₂-NPs. Moreover, mixed form and small particles of TiO₂-NPs increased the percentage of DNA in tail. In addition, short-term exposure could detect more DNA damage. The size, coating, duration, and concentration of TiO₂-NPs influenced MN formation. This study presented that TiO₂-NP exposure could cause genotoxicity in vitro. The physicochemical properties of TiO₂-NPs and experimental protocols influence the genotoxic effects in vitro. Comet and gene mutation assays may be more sensitive to the detection of TiO₂-NP genotoxic effects.

The Puzzling Potential of Carbon Nanomaterials: General Properties, Application, and Toxicity

Being a member of the nanofamily, carbon nanomaterials exhibit specific properties that mostly arise from their small size. They have proved to be very promising for application in the technical and biomedical field. A wide spectrum of use implies the inevitable presence of carbon nanomaterials in the environment, thus potentially endangering their whole nature. Although scientists worldwide have conducted research investigating the impact of these materials, it is evident that there are still significant gaps concerning the knowledge of their mechanisms, as well as the prolonged and chronic exposure and effects. This manuscript summarizes the most prominent representatives of carbon nanomaterial groups, giving a brief review of their general physico-chemical properties, the most common use, and toxicity profiles. Toxicity was presented through genotoxicity and the activation of the cell signaling pathways, both including in vitro and in vivo models, mechanisms, and the consequential outcomes. Moreover, the acute toxicity of fullerenol, as one of the most commonly investigated members, was briefly presented in the final part of this review. Thinking small can greatly help us improve our lives, but also obliges us to deeply and comprehensively investigate all the possible consequences that could arise from our pure-hearted scientific ambitions and work.

N-Acetylcysteine Nanocarriers Protect against Oxidative Stress in a Cellular Model of Parkinson's Disease

Oxidative stress is a key mediator in the development and progression of Parkinson's disease (PD). The antioxidant n-acetylcysteine (NAC) has generated interest as a disease-modifying therapy for PD but is limited due to poor bioavailability, a short half-life, and limited access to the brain. The aim of this study was to formulate and utilise mitochondria-targeted nanocarriers for delivery of NAC alone and in combination with the iron chelator deferoxamine (DFO), and assess their ability to protect against oxidative stress in a cellular rotenone PD model. Pluronic F68 (P68) and dequalinium (DQA) nanocarriers were prepared by a modified thin-film hydration method. An MTT assay assessed cell viability and iron status was measured using a ferrozine assay and ferritin immunoassay. For oxidative stress, a modified cellular antioxidant activity assay and the thiobarbituric acid-reactive substances assay and mitochondrial hydroxyl assay were utilised. Overall, this study demonstrates, for the first time, successful formulation of NAC and NAC + DFO into P68 + DQA nanocarriers for neuronal delivery. The results indicate that NAC and NAC + DFO nanocarriers have the potential characteristics to access the brain and that 1000 μM P68 + DQA NAC exhibited the strongest ability to protect against reduced cell viability (p = 0.0001), increased iron (p = 0.0033) and oxidative stress (p ≤ 0.0003). These NAC nanocarriers therefore demonstrate significant potential to be transitioned for further preclinical testing for PD.

Effect of N-acetylcysteine against Vancomycin-Induced Nephrotoxicity: A Randomized Controlled Clinical Trial

BACKGROUND

The proposed mechanism of vancomycin-induced nephrotoxicity (VIN) is indirect production of reactive oxygen species in the kidney tissue. This study aimed to investigate the effectiveness of N-acetylcysteine (NAC), an anti-oxidant agent, in the prevention of VIN.

METHODS

Patients who received vancomycin for any indication were randomly divided to drug (NAC) and control groups. The patients in the drug group received oral NAC 600 mg every 12 hours for 10 days, starting concurrently with vancomycin. Serum creatinine (SCr) levels and blood urea nitrogen (BUN) as well as creatinine clearance (CrCl) and 12-hour urine volume were recorded at baseline, every other day during the study, and 12 hours after the last dose of vancomycin on the 10th day. Furthermore, the cases of acute kidney injury (AKI; ≥ 0.5 mg/dL or at least 50% increase in serum creatinine from baseline) were recorded in the two groups.

RESULTS

Over the study period, 84 and 95 patients completed the study in drug and control groups, respectively. SCr and CrCl were significantly lower and higher, respectively, at all-time points (except for baseline) in the NAC compared to the control group. Furthermore, although not statistically significant, 12 cases of vancomycin-induced AKI were observed in the control group (12.63%), while 4 cases (4.76%) were reported from drug group (P = 0.066; relative risk [RR] = 0.377, 95% CI: 0.126-1.124).

CONCLUSION

NAC has the potential for reduction of VIN. However, more studies are necessary to confirm this effect.

Synergistic protective effect of N-acetylcysteine and taurine against cisplatin-induced nephrotoxicity in rats

Cisplatin (cis-diaminedichloroplatinum II; CDDP) is an effective anticancer drug, but it has limitations because of its nephrotoxicity. This study investigates the protective effect of N-acetylcysteine (NAC) and taurine (TAU), both individually and in combination, against CDDP nephrotoxicity in rats. For this purpose, 48 male rats were assigned into eight groups (n=6) as follows: 1) control group, 2) NAC group, 3) TAU group, 4) NAC-TAU group, 5) CDDP group, 6) CDDP-NAC group, 7) CDDP-TAU group, and 8) CDDP-NAC-TAU group. Cisplatin was administered as a single intraperitoneal injection at a concentration of 6 mg/kg. Three days after CDDP administration, NAC (50 mg/kg) and/or TAU (50 mg/kg) were administered three times weekly for four consecutive weeks. Kidney function markers in serum, urinary glucose and protein, as well as oxidant and antioxidant parameters in renal tissue were assessed. Administration of CDDP significantly elevated urinary glucose and protein, as well as serum creatinine, urea, and uric acid. Moreover, CDDP enhanced lipid peroxidation and suppressed the major enzymatic antioxidants in the kidney tissue. Treatment with NAC or TAU protected against the alterations in the serum, urine, and renal tissue when used individually along with CDDP. Furthermore, a combined therapy of both was more effective in ameliorating CDDP-induced nephrotoxicity, which points out to their synergistic effect.

Amorphous silica nanoparticles trigger vascular endothelial cell injury through apoptosis and autophagy via reactive oxygen species-mediated MAPK/Bcl-2 and PI3K/Akt/mTOR signaling

Environmental exposure to silica nanoparticles (SiNPs) is inevitable due to their widespread application in industrial, commercial, and biomedical fields. In recent years, most investigators focus on the evaluation of cardiovascular effects of SiNPs in vivo and in vitro. Endothelial injury and dysfunction is now hypothesized to be a dominant mechanism in the development of cardiovascular diseases. This study aimed to explore interaction of SiNPs with endothelial cells, and extensively investigate the exact effects of reactive oxygen species (ROS) on the signaling molecules and cytotoxicity involved in SiNPs-induced endothelial injury. Significant induction of cytotoxicity as well as oxidative stress, apoptosis, and autophagy was observed in human umbilical vein endothelial cells following the SiNPs exposure (P<0.05). The oxidative stress was induced by ROS generation, leading to redox imbalance and lipid peroxidation. SiNPs induced mitochondrial dysfunction, characterized by membrane potential collapse, and elevated Bax and declined bcl-2 expression, ultimately leading to apoptosis, and also increased number of autophagosomes and autophagy marker proteins, such as LC3 and p62. Phosphorylated ERK, PI3K, Akt, and mTOR were significantly decreased, but phosphorylated JNK and p38 MAPK were increased in SiNPs-exposed endothelial cells. In contrast, all of these stimulation phenomena were effectively inhibited by N-acetylcysteine. The N-acetylcysteine supplement attenuated SiNPs-induced endothelial toxicity through inhibition of apoptosis and autophagy via MAPK/Bcl-2 and PI3K/Akt/mTOR signaling, as well as suppression of intracellular ROS property via activating antioxidant enzyme and Nrf2 signaling. In summary, the results demonstrated that SiNPs triggered autophagy and apoptosis via ROS-mediated MAPK/Bcl-2 and PI3K/Akt/mTOR signaling in endothelial cells, and subsequently disturbed the endothelial homeostasis and impaired endothelium. Our findings may provide experimental evidence and explanation for cardiovascular diseases triggered by SiNPs. Furthermore, results hint that the application of antioxidant may provide a novel way for safer use of nanomaterials.

Cytotoxicity of Manganese (III) Complex in Human Breast Adenocarcinoma Cell Line Is Mediated by the Generation of Reactive Oxygen Species Followed by Mitochondrial Damage

Manganese (Mn) complexes are widely studied because of their important catalytic properties in synthetic and biochemical reactions. A Mn (III) complex of an amidoamine ligand was synthesized using a tetradentate amidoamine ligand. In this study, the Mn (III) complex was evaluated for its biological activity by measuring its cytotoxicity in human breast adenocarcinoma cell line (MCF-7). Cytotoxic effects of the Mn (III) complex were determined using established biomarkers in an attempt to delineate the mechanism of action and the utility of the complex as a potential anticancer drug. The Mn (III) complex induces cell death in a dose- and time-dependent manner as shown by microculture tetrazolium assay, a measure of cytotoxic cell death. Our results demonstrated that cytotoxic effects were significantly increased at higher concentrations of Mn (III) complex and with longer time of treatment. The IC50 (Inhibitor concentration that results in 50% cell death) value of Mn (III) complex in MCF-7 cells was determined to be 2.5 mmol/L for 24 hours of treatment. In additional experiments, we determined the Mn (III) complex–mediated cell death was due to both apoptotic and nonspecific necrotic cell death mechanisms. This was assessed by ethidium bromide/acridine orange staining and flow cytometry techniques. The Mn (III) complex produced reactive oxygen species (ROS) triggering the expression of manganese superoxide dismutase 1 and ultimately damaging the mitochondrial function as is evident by a decline in mitochondrial membrane potential. Treatment of the cells with free radical scavenger, N, N-dimethylthiourea decreased Mn (III) complex–mediated generation of ROS and attenuated apoptosis. Together, these results suggest that the Mn (III) complex–mediated MCF-7 cell death utilizes combined mechanism involving apoptosis and necrosis perhaps due to the generation of ROS.

The role of intracellular redox imbalance in nanomaterial induced cellular damage and genotoxicity: a review

The terms oxidative stress, free radical generation, and intracellular antioxidant protection have become part of everyday nanotoxicology terminology. In recent years, an ever increasing number of in vitro and in vivo studies have implicated disruptions to the redox balance and oxidative stress as one of the main contributors to nanomaterial (NM) induced adverse effects. One of the most important and widely investigated of these effects is genotoxicity. In general, systems that defend an organism against oxidative damage to DNA are very complex and include prevention of reactive oxygen species (ROS) production, neutralizing ROS (scavengers), enzymatic nucleotide pool sanitation, and DNA repair. This review discusses the importance of the maintenance of the redox balance in this context before examining studies that have investigated engineered NM induced redox imbalance and genotoxicity. Furthermore, we identify data gaps, and highlight a number of issues that exist with the methodologies that are routinely utilized to investigate intracellular ROS production or anti-oxidant depletion. We conclude that for a large number of engineered NM types changes in the redox balance toward oxidative stress are normally associated with DNA damage.

Genotoxicity of titanium dioxide nanoparticles

Titanium dioxide nanoparticles (TiO₂-NPs, <100 nm) are increasingly being used in pharmaceuticals and cosmetics due to the unique properties derived from their small sizes. However, their large surface-area to mass ratio and high redox potential may negatively impact human health and the environment. TiO₂-NPs can cause inflammation, pulmonary damage, fibrosis, and lung tumors and they are possibly carcinogenic to humans. Because cancer is a disease involving mutation, there are a large number of studies on the genotoxicity of TiO₂-NPs. In this article, we review the results that have been reported in the literature, with a focus on data generated from the standard genotoxicity assays. The data include genotoxicity results from the Ames test, in vitro and in vivo Comet assay, in vitro and in vivo micronucleus assay, sister chromatid exchange assay, mammalian cell hypoxanthine-guanine phosphoribosyl transferase gene assay, the wing somatic mutation and recombination assay, and the mouse phosphatidylinositol glycan, class A gene assay. Inconsistent results have been found in these assays, with both positive and negative responses being reported. The in vitro systems for assessing the genotoxicity of TiO₂-NPs have generated a greater number of positive results than the in vivo systems, and tests for DNA and chromosome damage have produced more positive results than the assays measuring gene mutation. Nearly all tests for measuring the mutagenicity of TiO₂-NPs were negative. The current data indicate that the genotoxicity of TiO₂-NPs is mediated mainly through the generation of oxidative stress in cells.

Targeting 3-phosphoinositide-dependent protein kinase 1 by N-acetyl-cysteine through activation of peroxisome proliferators activated receptor alpha in human lung cancer cells, the role of p53 and p65

Background

N-Acetyl-Cysteine (NAC), a natural sulfur-containing amino acid derivative, and peroxisome proliferators activated receptor alpha (PPARα) ligand have been shown to have anticancer properties. However, the mechanisms by which these agents inhibit human non-small cell lung carcinoma (NSCLC) cell growth have not been well elucidated.

Methods

Small interfering RNAs (siRNAs) were used to knockdown 3-phosphoinositide-dependent protein kinase 1 (PDK1), PPARα, p65 and p53 genes; Western Blot was performed to detect the protein expression of PDK1, PPARα, p65 and p53; Cell viability and MTT assays were carried out to determine the cell proliferation; Transient transfection and Dual-Luciferase Reporter assays were used to transfect siRNAs or exogenous expression vectors, and to measure the gene promoter activity.

Results

We showed that NAC inhibited NSCLC cell proliferation through reduction of PDK1 expression. NAC also induced the protein expression of PPARα. While PPARα ligand enhanced, PPARα antagonist and siRNA abrogated the effect of NAC on PDK1 promoter activity, protein expression and cell growth. Overexpression of PDK1 diminished the inhibitory effect of NAC on cell proliferation. NAC induced p53 and reduced p65 protein expression through activation of PPARα. Silencing of p53 and overexpression of p65 blocked the effect of NAC on PDK1 promoter activity and protein expression.

Conclusion

Our results show that NAC inhibits PDK1 expression through PPARα-mediated induction of p53 and inhibition of p65 protein expression. PPARα ligand enhances the effect of NAC. This ultimately inhibits NSCLC cell growth. This study unveils a novel mechanism by which NAC in combination with PPARα ligand inhibits growth of human lung carcinoma cells.

N-acetylcysteine attenuates subcutaneous administration of bleomycin-induced skin fibrosis and oxidative stress in a mouse model of scleroderma

BACKGROUND

Several lines of evidence suggest that the generation of reactive oxygen species (ROS) is of major importance in the pathogenesis of scleroderma, and thus antioxidant therapy may be useful for patients with an impaired oxidative defence mechanism.

AIM

To examine the effect of N-acetylcysteine (NAC) on skin fibrosis and oxidative stress in a bleomycin (BLM)-induced mouse model of scleroderma.

METHODS

We used this mouse model to evaluate the effect of NAC on skin fibrosis and oxidative stress. Skin fibrosis was evaluated by histopathological examination and hydroxyproline content. To measure lipid peroxidation, we used a thiobarbituric acid-reactive species, malondialdehyde (MDA). Oxidative protein damage (carbonyl content) and the activities of catalase (CAT) and superoxide dismutase (SOD) were determined to evaluate oxidative stress in the skin tissue.

RESULTS

Treatment with NAC attenuated the skin fibrosis induced by BLM, significantly reducing the MDA and protein carbonyl content in these mice. SOD activity in BLM-only mice and BLM plus NAC-treated mice was increased compared with control mice. However, there was no significant difference in skin SOD activity of mice treated with both BLM and NAC compared with those treated with BLM only. In addition, CAT activity was not altered in the BLM plus NAC mice.

CONCLUSIONS

NAC treatment attenuates skin fibrosis in a BLM-induced mouse model of scleroderma, and this is associated with diminished oxidative stress. The results suggest that NAC may be a potential therapeutic agent for patients with scleroderma.

Mechanisms of genotoxicity. A review of in vitro and in vivo studies with engineered nanoparticles

Engineered nanoparticles (NPs) are widely used in different technologies but their unique properties might also cause adverse health effects. In reviewing recent in vitro and in vivo genotoxicity studies we discuss potential mechanisms of genotoxicity induced by NPs. Various factors that may influence genotoxic response, including physico-chemical properties and experimental conditions, are highlighted. From 4346 articles on NP toxicity, 112 describe genotoxicity studies (94 in vitro, 22 in vivo). The most used assays are the comet assay (58 in vitro, 9 in vivo), the micronucleus assay (31 in vitro, 14 in vivo), the chromosome aberrations test (10 in vitro, 1 in vivo) and the bacterial reverse mutation assay (13 studies). We describe advantages and potential problems with different methods and suggest the need for appropriate methodologies to be used for investigation of genotoxic effects of NPs, in vitro and in vivo.

Protective effects of erythropoietin and N-acetylcysteine on methotrexate-induced lung injury in rats

OBJECTIVE

Methotrexate (MTX) is known to have deleterious side effects on lung tissue. We aimed to investigate the effects of erythropoietin (EPO) and N-acetyl-cysteine (NAC) on MTX-induced lung injury in rats.

STUDY DESIGN

Animal experiment.

MATERIAL AND METHODS

Twenty-six female Sprague-Dawley rats were divided into 4 groups. Sham group, 0.3 mL saline; MTX group, 5 mg/kg MTX; EPO group, 5mg/kg MTX and 2000 IU/kg EPO; NAC group, 5 mg/kg MTX and 200 mg/kg NAC were administered once daily for 4 consecutive days. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and inflammation and congestion scores in lung tissues were evaluated.

RESULTS

In MTX group MDA were significantly higher, CAT and SOD were significantly lower than in sham, EPO and NAC groups (p<0.005). In EPO group MDA, CAT, and SOD were higher, but not significant than those in group NAC (p>0.005). In group MTX both scores were significantly higher than in sham (p<0.005). The congestion score of group MTX was significantly higher than those of group EPO and NAC (p<0.005).

CONCLUSION

EPO and NAC have significant preventive effects on MTX-induced lung injury in rats. Decreased antioxidant capacity and increased MDA level may cause the oxidative damage in MTX group. Also, higher antioxidant capacity and lower MDA level may be a response to oxidative stress in EPO and NAC groups.

Salusin-β accelerates inflammatory responses in vascular endothelial cells via NF-κB signaling in LDL receptor-deficient mice in vivo and HUVECs in vitro

The bioactive peptide salusin-β is highly expressed in human atheromas; additionally, infusion of antiserum against salusin-β suppresses the development of atherosclerosis in atherogenic mice. This study examined the roles of salusin-β in vascular inflammation during atherogenesis. Infusion of antiserum against salusin-β attenuated the induction of VCAM-1, monocyte chemoattractant protein (MCP)-1, and IL-1β and as well as nuclear translocation of NF-κB in aortic endothelial cells (ECs) of LDL receptor-deficient mice, which led to the prevention of monocyte adhesion to aortic ECs. In vitro experiments indicated that salusin-β directly enhances the expression levels of proinflammatory molecules, including VCAM-1, MCP-1, IL-1β, and NADPH oxidase 2, as well as THP-1 monocyte adhesion to cultured human umbilical vein ECs (HUVECs). Both salusin-β-induced VCAM-1 induction and monocyte/HUVEC adhesion were suppressed by pharmacological inhibitors of NF-κB, e.g., Bay 11-7682 and curcumin. Furthermore, the VCAM-1 induction was significantly prevented by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY-294002, whereas it was accelerated by the ERK inhibitor, U-0126. Treatment of HUVECs with salusin-β, but not with salusin-α, accelerated oxidative stress and nuclear translocation of NF-κB as well as phosphorylation and degradation of IκB-α, an endogenous inhibitor of NF-κB. Thus, salusin-β enhanced monocyte adhesion to vascular ECs through NF-κB-mediated inflammatory responses in ECs, which can be modified by PI3K or ERK signals. These findings are suggestive of a novel role of salusin-β in atherogenesis.

Peroxyacetyl nitrate-induced oxidative and calcium signaling events leading to cell death in ozone-sensitive tobacco cell-line

It has long been concerned that some secondary air pollutants such as smog components, ozone (O3) and peroxyacetyl nitrate (PAN), are highly phytotoxic even at low concentrations. Compared with the biology of O3, we largely lack the information on the toxicity model for PAN at the cellular signaling levels. Here, we studied the cell-damaging impact of PAN using suspension culture of smog-sensitive tobacco variety (Bel-W3). The cells were exposed to freshly synthesized PAN and the induced cell death was assessed under microscope after staining with Evans blue. Involvement of reactive oxygen species (ROS) in PAN toxicity was suggested by PAN-dependently increased intracellular H2O2 and also by the cell-protective effects of ROS scavengers and related inhibitors. Calcium chelator also lowered the level of PAN-induced cell death, indicating that Ca2+ is also involved. Using a transgenic cell line expressing aequorin, an increase in cytosolic Ca2+ concentration responsive to the pulse of PAN, but sensitive to Ca2+ channel blockers, was recorded, indicating that Ca2+ channels are activated by PAN or PAN-derived signals. Above data show some similarity between the signaling mechanisms responsive to O3 and PAN.