Concentration-dependent induction of reactive oxygen species, cell cycle arrest and apoptosis in human liver cells after nickel nanoparticles exposure

Nanoparticle Polymers Influence on Cardiac Health: Good or Bad for Cardiac Physiology?

Cardiovascular diseases (CVD) are one of the leading causes of death and morbidity worldwide. Lifestyle modifications, medications, and addressing epidemiological factors have long been at the forefront of targeting therapeutics for CVD. Treatments can be further complicated given the intersection of gender, age, unique comorbidities, and healthcare access, among many other factors. Therefore, expanding treatment and diagnostic modalities for CVD is absolutely necessary. Nanoparticles and nanomaterials are increasingly being used as therapeutic and diagnostic modalities in various disciplines of biomedicine. Nanoparticles have multiple ways of interacting with the cardiovascular system. Some of them alter cardiac physiology by impacting ion channels, whereas others influence ions directly or indirectly, improving cellular death via decreasing oxidative stress.  While embedding nanoparticles into therapeutics can help enhance healthy cardiovascular function in other scenarios, they can also impair physiology by increasing reactive oxidative species and leading to cardiotoxicity. This review explores different types of nanoparticles, their effects, and the applicable dosages to create a better foundation for understanding the current research findings.

Effective-by-method for the preparation of folic acid-coated TiO2 nanoparticles with high targeting potential for apoptosis induction against bladder cancer cells (T24)

The research's goal is to create the surfaces of titanium dioxide nanoparticles (TiO2 NPs) in a layer of folic acid (FA) that can effectively target human bladder cancer cells (T24). An efficient method for creating FA-coated TiO2 NPs was used, and many tools have been used to analyze its physicochemical properties. The cytotoxic effects of FA-coated NPs on T24 cells and the mechanisms of apoptosis generation were examined employing a variety of methodologies. The prepared FA-coated TiO2 NPs suspensions with a hydrodynamic diameter around 37 nm and a negative surface charge of -30 mV reduced T24 cell proliferation with stronger IC50 value (21.8 ± 1.9 μg/ml) than TiO2 NPs (47.8 ± 2.5 μg/ml). This toxicity resulted in apoptosis induction (16.63%) that was caused through enhanced reactive oxygen species formation and stopping the cell cycle over G2/M phase. Moreover, FA-TiO2 NPs raised the expression levels of P53, P21, BCL2L4, and cleaved Caspase-3, while decreasing Bcl-2, Cyclin B, and CDK1 in treated cells. Overall, these findings revealed efficient targeting of the FA-TiO2 NPs resulted in increasing cellular internalization caused increased apoptosis in T24 cells. As a result, FA-TiO2 NPs might be a viable treatment for human bladder cancer.

Nickel Nanoparticles Induced Hepatotoxicity in Mice via Lipid-Metabolism-Dysfunction-Regulated Inflammatory Injury

Nickel nanoparticles (NiNPs) have wide applications in industry and biomedicine due to their unique characteristics. The liver is the major organ responsible for nutrient metabolism, exogenous substance detoxification and biotransformation of medicines containing nanoparticles. Hence, it is urgent to further understand the principles and potential mechanisms of hepatic effects on NiNPs administration. In this study, we explored the liver impacts in male C57/BL6 mice through intraperitoneal injection with NiNPs at doses of 10, 20 and 40 mg/kg/day for 7 and 28 days. The results showed that NiNPs treatment increased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and induced pathological changes in liver tissues. Moreover, hepatic triglyceride (TG) content and lipid droplet deposition identified via de novo lipogenesis (DNL) progression were enhanced after NiNPs injection. Additionally, sustained NiNPs exposure induced a remarkable hepatic inflammatory response, significantly promoted endoplasmic reticulum stress (ER stress) sensors Ire1α, Perk and Atf6, and activated the occurrence of liver cell apoptosis. Overall, the research indicated that NiNPs exposure induced liver injury and disturbance of lipid metabolism. These findings revealed the public hazard from extreme exposure to NiNPs and provided new information on biological toxicity and biosafety evaluation.

Intraperitoneal hepato-renal toxicity of zinc oxide and nickel oxide nanoparticles in male rats: biochemical, hematological and histopathological studies

In recent years, zinc oxide (ZnO) and nickel oxide (NiO) nanoparticles (NPs) have become more prevalent in commercial and industrial products. However, questions have been raised regarding their potential harm to human health. Limited studies have been conducted on their intraperitoneal toxicity in rats, and their co-exposure effects remain uncertain. Therefore, this study aimed to investigate some biological responses induced by a single intraperitoneal injection of ZnO-NPs (200 mg/kg) and/or NiO-NPs (50 mg/kg) in rats over time intervals. Blood and organ samples were collected from 36 male rats for hematological, biochemical, oxidative stress, and histological analysis. Results showed that the administration of NPs reduced the body and organ weights as well as red blood cell (RBC) indices and altered white blood cell (WBC) and platelet (PLT) counts. The experimental groups exhibited elevated levels of aspartate aminotransferase (AST), alanine transaminase (ALT), creatinine (CREA), urea, lipid profile, glucose (GLU), total protein (TP), albumin (ALB) and malondialdehyde (MDA), and decreased uric acid (UA), superoxide dismutase (SOD), and glutathione (GSH). Histological observations also revealed architectural damages in liver and kidneys. These alterations were time-dependent and varied in their degree of toxicity. Co-exposure of NPs initially lessened the damage but increased it afterwards compared to individual exposure. In conclusion, intraperitoneal injection of ZnO-NPs and/or NiO-NPs alters biological processes and induces oxidative stress in rats' liver and kidneys in a time-dependent manner, with NiO-NPs being more potent than ZnO-NPs. Furthermore, co-exposed NPs initially appeared to be antagonistic to one another while further aiming toward synergism.

Nickel induces hepatotoxicity by mitochondrial biogenesis, mitochondrial dynamics, and mitophagy dysfunction

Nickel (Ni) is an important and widely hazardous chemical industrial waste. Excessive Ni exposure could cause multi-organs toxicity in human and animals. Liver is the major target organ of Ni accumulation and toxicity, however, the precise mechanism is still unclear. In this study, nickel chloride (NiCl₂ )-treatment induced hepatic histopathological changes in the mice, and, transmission electron microscopy results showed mitochondrial swollen and deformed of hepatocyte. Next, the mitochondrial damages including mitochondrial biogenesis, mitochondrial dynamics, and mitophagy were measured after NiCl₂ administration. The results showed that NiCl₂ suppressed mitochondrial biogenesis by decreasing PGC-1α, TFAM, and NRF1 protein and mRNA expression levels. Meanwhile, the proteins involved in mitochondrial fusion were reduced by NiCl₂ , such as Mfn1 and Mfn2, however, mitochondrial fission proteins Drip1 and Fis1 were significantly increased. The up-regulation of mitochondrial p62 and LC3II expression indicated that NiCl₂ increased mitophagy in the liver. Moreover, the receptor-mediated mitophagy and ubiquitin (Ub)-dependent mitophagy were detected. NiCl₂ promoted PINK1 accumulation and Parkin recruitment on mitochondria. And, the receptor proteins of mitophagy Bnip3 and FUNDC1 were increased in the NiCl₂ -treated mice liver. Overall, these results show that NiCl₂ could induce mitochondria damage in the liver of mice, and, dysfunction of mitochondrial biogenesis, mitochondrial dynamics and mitophagy involved in the molecular mechanism of NiCl₂ -induced hepatotoxicity.

Selenium nanoparticles improve nickel-induced testosterone synthesis disturbance by down-regulating miR-708-5p/p38 MAPK pathway in Leydig cells

The present study was designed to investigate the role of miR-708-5p/p38 mitogen-activated protein kinase (MAPK) pathway during the mechanism of selenium nanoparticles (Nano-Se) against nickel (Ni)-induced testosterone synthesis disorder in rat Leydig cells. We conducted all procedures based on in vitro culture of rat primary Leydig cells. After treating Leydig cells with Nano-Se and NiSO₄ alone or in combination for 24 h, we determined the cell viability, reactive oxygen species (ROS) levels, testosterone production, and the protein expression of key enzymes involved in testosterone biosynthesis: steroidogenic acute regulatory (StAR) and cytochrome P450 cholesterol side chain cleavage enzyme (CYP11A1). The results indicated that Nano-Se antagonized cytotoxicity and eliminated ROS generation induced by NiSO₄ , suppressed p38 MAPK protein phosphorylation and reduced miR-708-5p expression. Importantly, we found that Nano-Se upregulated the expression of testosterone synthase and increased testosterone production in Leydig cells. Furthermore, we investigated the effects of p38 MAPK and miR-708-5p using their specific inhibitor during Nano-Se against Ni-induced testosterone synthesis disorder. The results showed that Ni-inhibited testosterone secretion was alleviated by Nano-Se co-treatment with p38 MAPK specific inhibitor SB203580 and miR-708-5p inhibitor, respectively. In conclusion, these findings suggested Nano-Se could inhibit miR-708-5p/p38 MAPK pathway, and up-regulate the key enzymes protein expression for testosterone synthesis, thereby antagonizing Ni-induced disorder of testosterone synthesis in Leydig cells.

The HL-60 human promyelocytic cell line constitutes an effective in vitro model for evaluating toxicity, oxidative stress and necrosis/apoptosis after exposure to black carbon particles and 2.45 GHz radio frequency

The cellular and molecular mechanisms by which atmospheric pollution from particulate matter and/or electromagnetic fields (EMFs) may prove harmful to human health have not been extensively researched. We analyzed whether the combined action of EMFs and black carbon (BC) particles induced cell damage and a pro-apoptotic response in the HL-60 promyelocytic cell line when exposed to 2.45 GHz radio frequency (RF) radiation in a gigahertz transverse electromagnetic (GTEM) chamber at sub-thermal specific absorption rate (SAR) levels. RF and BC induced moderately significant levels of cell damage in the first 8 or 24 h for all exposure times/doses and much greater damage after 48 h irradiation and the higher dose of BC. We observed a clear antiproliferative effect that increased with RF exposure time and BC dose. Oxidative stress or ROS production increased with time (24 or 48 h of radiation), BC dose and the combination of both. Significant differences between the proportion of damaged and healthy cells were observed in all groups. Both radiation and BC participated separately and jointly in triggering necrosis and apoptosis in a programmed way. Oxidative-antioxidant action activated mitochondrial anti-apoptotic BCL2a gene expression after 24 h irradiation and exposure to BC. After irradiation of the cells for 48 h, expression of FASR cell death receptors was activated, precipitating the onset of pro-apoptotic phenomena and expression and intracellular activity of caspase-3 in the mitochondrial pathways, all of which can lead to cell death. Our results indicate that the interaction between BC and RF modifies the immune response in the human promyelocytic cell line and that these cells had two fates mediated by different pathways: necrosis and mitochondria-caspase dependent apoptosis. The findings may be important in regard to antimicrobial, inflammatory and autoimmune responses in humans.

Physicochemical Transformations of Silver Nanoparticles in the Oro-Gastrointestinal Tract Mildly Affect Their Toxicity to Intestinal Cells In Vitro: An AOP-Oriented Testing Approach

The widespread use of silver nanoparticles (Ag NPs) in food and consumer products suggests the relevance of human oral exposure to these nanomaterials (NMs) and raises the possibility of adverse effects in the gastrointestinal tract. The aim of this study was to investigate the toxicity of Ag NPs in a human intestinal cell line, either uncoated or coated with polyvinylpyrrolidone (Ag PVP) or hydroxyethylcellulose (Ag HEC) and digested in simulated gastrointestinal fluids. Physicochemical transformations of Ag NPs during the different stages of in vitro digestion were identified prior to toxicity assessment. The strategy for evaluating toxicity was constructed on the basis of adverse outcome pathways (AOPs) showing Ag NPs as stressors. It consisted of assessing Ag NP cytotoxicity, oxidative stress, genotoxicity, perturbation of the cell cycle and apoptosis. Ag NPs caused a concentration-dependent loss of cell viability and increased the intracellular level of reactive oxygen species as well as DNA damage and perturbation of the cell cycle. In vitro digestion of Ag NPs did not significantly modulate their toxicological impact, except for their genotoxicity. Taken together, these results indicate the potential toxicity of ingested Ag NPs, which varied depending on their coating but did not differ from that of non-digested NPs.

Decreased thioredoxin reductase 3 expression promotes nickel-induced damage to cardiac tissue via activating oxidative stress-induced apoptosis and inflammation

Thioredoxin reductase 3 (Txnrd3) plays a crucial role in antioxidant and anti-cancer activities, and sperm maturation. The damage of heavy metals, including Nickel (Ni), is the most prominent harm in social development, and hampering Txnrd3 might exacerbate Ni-induced cardiac damage. In this study, a total of 160 8-week-old C57BL/N male mice with 25-30 g weight of Txnrd3+/+ wild-type and Txnrd3-/- homozygote-type were randomly divided into eight groups. The mice in the control and Ni groups were gavaged with distilled water and a freshly prepared 10 mg/kg NiCl₂ solution. Melatonin (Mel) groups were administered at a concentration of 2 mg/kg for 21 days at the mice's 0.1 ml/10 g body weight. Ni exposure up-regulated the messenger RNA (mRNA) levels of mitochondrial apoptosis (caspase-3, caspase-9, cytochrome c, p53, and BAX), autophagy (LC3, ATG 1, ATG 7, and Beclin-1), and inflammation (TNF-α, COX 2, IL-1β, IL-2, IL-6, and IL-7)-related markers, but down-regulated the mRNA levels of BCL-2, p62 and mTOR (p < .05). Ni exposure decreased the expression of BCL-2 and p62 protein but increased the expression levels of caspase-3, caspase-9, cytochrome c, p53, BAX, ATG 7, Beclin-1, TNF-α, COX 2, IL-1β and IL-2 protein (p < .05). Ni increased the contents of glutathione disulfide (GSSG) and malondialdehyde (MDA) and decreased the activities of catalase (CAT) and total superoxide dismutase (T-SOD) (p < .05). Decreased Txnrd3 expression significantly exacerbated changes compared to the Ni exposure (p < .05). Mel significantly attenuated these changes, but the effect decreased when Txnrd3 was inhibited (p < .05). In conclusion, decreased Txnrd3 expression promoted Ni-induced mitochondrial apoptosis and inflammation via oxidative stress and aggravated heart damage in mice. Decreased Txnrd3 expression significantly reduced the protective effect of Mel to Ni exposure.

Nickel nanoparticles exert cytotoxic effects on trophoblast HTR-8/SVneo cells possibly via Nrf2/MAPK/caspase 3 pathway

Nickel nanoparticles are widely used in the industry and may affect the reproductive system. The potential molecular mechanism of exposing the first-trimester trophoblast cell line (HTR-8/SVneo) to nickel nanoparticles remains unclear. Hence, the aim of this study was to investigate the in vitro cytotoxicity of Ni NPs on HTR-8/SVneo cells. HTR-8/SVneo cells were subjected to various concentrations (0, 2.5, 5, 7.5, 10, and 12.5 μg/cm²) of Ni NPs. The toxicity of the Ni NPs was evaluated in HTR-8/SVneo cells by measuring cell viability. The underlying mechanism of nickel nanoparticles toxicity to HTR-8/SVneo cells was determined by measuring the content of intracellular reactive oxygen species, mitochondrial membrane potential, and the rate of cell apoptosis and cell cycle, by measuring adenosine triphosphate levels, intracellular lipid peroxidation malondialdehyde, total superoxide dismutase, and CuZn/Mn-SOD activities, and by determining proteins related to Nrf2, MAPK, and Cytochrome c. Our results showed that the nickel nanoparticles treatment reduced the viability of HTR-8/SVneo cells, while it increased their oxidative stress and lowered their mitochondrial respiratory capacity. Additionally, the nickel nanoparticles treatment induced cell S-phase arrest and apoptosis. These molecular events may be linked to the oxidative stress-Nrf2 pathway/MAPK/Caspase 3 cascade. Thus, nickel nanoparticles exert cytotoxic effects on HTR-8/SVneo cells, which could affect the function of the placenta in human.

Combined effect of single-walled carbon nanotubes and cadmium on human lung cancer cells

Co-exposure of widely used single-walled carbon nanotubes (SWCNTs) and ubiquitous cadmium (Cd) to humans through ambient air is unavoidable. Studies on joint toxicity of SWCNTs and Cd in human cells are scarce. We aimed to investigate the joint effects of SWCNTs and Cd in human lung epithelial (A549) cells. Results showed that SWCNTs were safe while Cd induce significant toxicity to A549 cells. Remarkably, Cd-induced cell viability reduction, lactate dehydrogenase leakage, cell cycle arrest, dysregulation of apoptotic gene (p53, bax, bcl-2, casp3, and casp9), and mitochondrial membrane potential depletion were significantly mitigated following SWCNTs co-exposure. Cd-induced intracellular level of reactive oxygen species, hydrogen peroxide, and lipid peroxidation were significantly attenuated by SWCNT co-exposure. Moreover, glutathione depletion and lower activity of antioxidant enzymes after Cd exposure were also effectively abrogated by co-exposure of SWCNTs. Inductively coupled plasma-mass spectrometry study indicated that higher adsorption of Cd on SCWNTs might decreased cellular uptake and the toxic potential of Cd in A549 cells. Our work warranted further research to explore the potential mechanism of joint effects of SWCNTs and Cd at in vivo levels.

Effects of Nickel at Environmentally Relevant Concentrations on Human Corneal Epithelial Cells: Oxidative Damage and Cellular Apoptosis

Nickel (Ni) is ubiquitous in the environment and evidence has suggested that Ni can cause ocular surface inflammation, especially in fine particulate matter and personal products. Continuous daily exposure to Ni-containing dust may adversely impact the human cornea, whereas the underlying mechanism of this phenomenon remains not fully understood. Here, human corneal epithelial cells (HCEC) were employed to analyze the toxicity of Ni via detections of cell morphology, cell viability, reactive oxygen species production, cell apoptosis rate, and apoptotic gene expression levels after exposure for 24 h to uncover the damage of Ni to the cornea. A concentration-dependent inhibition of HCECs’ viability and growth was observed. In particular, Ni at 100 μM significantly decreased cell viability to 76%, and many cells displayed an abnormal shape and even induced oxidative damage of HCEC by increasing ROS to 1.2 times, and further led to higher apoptosis (24%), evidenced by up-regulation of apoptotic genes Caspase-8, Caspase-9, NF-κB, IL-1β, and Caspase-3, posing a risk of dry eye. Our study suggested that Ni induces apoptosis of HCEC through oxidative damage. Therefore, Ni pollution should be comprehensively considered in health risks or toxic effects on the ocular surface.

A review: Systematic research approach on toxicity model of liver and kidney in laboratory animals

Therapeutic experiments are commonly performed on laboratory animals to investigate the possible mechanism(s) of action of toxic agents as well as drugs or substances under consideration. The use of toxins in laboratory animal models, including rats, is intended to cause toxicity. This study aimed to investigate different models of hepatotoxicity and nephrotoxicity in laboratory animals to help researchers advance their research goals. The current narrative review used databases such as Medline, Web of Science, Scopus, and Embase and appropriate keywords until June 2021. Nephrotoxicity and hepatotoxicity models derived from some toxic agents such as cisplatin, acetaminophen, doxorubicin, some anticancer drugs, and other materials through various signaling pathways are investigated. To understand the models of renal or hepatotoxicity in laboratory animals, we have provided a list of toxic agents and their toxicity procedures in this review.

Strontium-Doped Nickel Oxide Nanoparticles: Synthesis, Characterization, and Cytotoxicity Study in Human Lung Cancer A549 Cells

In this manuscript, the grown and annealed strontium-doped nickel oxide nanoparticles (SrNiONPs) were synthesized using a precipitation method with nickel nitrate and strontium nitrate as precursor agents with trisodium citrate. Various characterization techniques, including X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-visible, and zeta sizer, were used to thoroughly examine the samples. The XRD pattern (21 nm) was used to calculate the size, phases, and crystallinity of the material (SrNiONPs). In addition to characterization, the material was tested for cytotoxicity in lung cancer cells (A549). The viability test in A549 cells was performed using [3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide] (MTT) and Neutral Red Uptake (NRU) assay with SrNiONPs concentration ranging from 1 to 100 μg/mL. According to the MTT and NRU data, the toxicity studies are dose-dependent. SrNiONPs also increased reactive oxygen species (ROS) and were involved in apoptosis (A549 cells). Furthermore, quantitative PCR (qPCR) data revealed that the mRNA levels of apoptotic genes marker like p53, bax, and caspase-3 were upregulated, whereas bcl-2, an anti-apoptotic gene, was downregulated. As a result, apoptosis was mediated by the p53, bax, caspase3, and bcl-2 pathways, implying a potential mechanism by which SrNiONPs mediate their toxicity.

Nickel nanoparticles affect the migration and invasion of HTR-8/SVneo cells by downregulating MMP2 through the PI3K/AKT pathway

Proper migration and invasion of extravillous trophoblast cells into the endometrium in early gestation is essential for successful embryo implantation. The development of nanotechnology has led to the emergence of nickel nanoparticles (Ni NPs), for which attendant health concerns are widespread. Ni NPs are known to affect reproduction and be embryotoxic, but whether they affect the migration and invasion functions of trophoblast cells is unclear. We investigated the effects of Ni NPs on the migration and invasion of HTR-8/SVneo in extravillous trophoblast cells and explored the possible role of the PI3K/AKT/MMP2 signaling pathway in this regard. Results showed that the migration and invasion of cells was significantly inhibited by the exposure of Ni NPs. The protein and mRNA levels of PI3K/AKT/MMP2 signaling pathway were significantly reduced with the increase in Ni NPs concentration. The presence of the PI3K activator 740Y-P partially attenuated the inhibition of cell migration and invasion by Ni NPs, confirming the involvement of this pathway. Thus, Ni NPs inhibit migration and invasion of human trophoblast HTR-8/SVneo cells by downregulating the PI3K/AKT/MMP2 signaling pathway. This study is important for the development of safety evaluation criteria for Ni NPs.

Nano-selenium attenuates mitochondrial-associated apoptosis via the PI3K/AKT pathway in nickel-induced hepatotoxicity in vivo and in vitro

The aim of this study was to investigate the protective effects of Nano-Se against nickel (Ni)-induced hepatotoxicity and the potential mechanism. Hence, we constructed in vivo and in vitro models of Ni-induced hepatotoxicity. Sprague-Dawley (SD) rats were exposed to nickel sulfate (NiSO₄ , 5.0 mg/kg, i.p.) with or without Nano-Se (0.5, 1, and 2 mg/kg, oral gavage) co-administration for 14 days, and HepG2 cells were exposed to NiSO₄ (1500 μM) with or without Nano-Se (20 μM) for 24 h. Nano-Se obviously prevented Ni-induced hepatotoxicity indicated by ameliorating pathological change and decreasing Ni accumulation in rat livers. Ni induced a significant increase in hepatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GSH-Px), and malondialdehyde (MDA) level, decreased the glutathione (GSH) content while compared to those in the control group. Nano-Se administration improved the hepatic antioxidant capacity through increase hepatic GSH contents and GSH-Px activity, decrease the activities of SOD, CAT, and MDA level. Nano-Se improved the cell viability, decreased active oxygen (ROS) generation and ameliorated morphological changes of nuclear structures in Ni-treated HepG2 cells. In addition, Nano-Se inhibited the Ni-induced increases of cytochrome c, caspase-9, cleaved caspase-3, increased PI3K and AKT phosphorylation both in vivo and in vitro. Besides, the PI3K inhibitor Y294002 could inhibit the protective effects of Nano-Se on apoptosis. Thus, Nano-Se significantly activates PI3K/AKT signaling to ameliorate apoptosis in Ni-induced hepatotoxicity.

Facile green synthesis of ZnO–CuO nanocomposites using areca catechu leaves and their in vitro antidiabetic and cytotoxicity studies

The fabrication and diverse applications of mixed oxides have received immense interest due to numerous prospects for better functional performance in tuning their properties compared to the basic metal oxides. Herein, we report synthesis of ZnO-CuO nanocomposites (NCs) using a simple and green route solution combustion method. The as-prepared ZnO-CuO NCs have been characterised through x-ray diffraction (XRD), energy dispersive x-ray (EDX) with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The results revealed that as-prepared ZnO-CuO NCs have spherical and rod-shaped structures with an average size between 10 and 30 nm. Further, ZnO-CuO NCs were tested for antidiabetic and anticancer properties. Amylase inhibition and MTT assays were carried out with different concentrations of NCs. The biological results depicted that the as-prepared nanocomposites exhibited significant cytotoxic effects with IC50 value of 13.29 μg mg−1. These observations further showed that the newly synthesised ZnO–CuO NCs are interesting and promising nanomaterials in pharmaceutical and healthcare sector.

Saad G. Induction of mitochondria mediated apoptosis in human ovarian cancer cells by folic acid coated tin oxide nanoparticles

PURPOSE

This study aims to prepare folic acid coated tin oxide nanoparticles (FA-SnO2 NPs) for specifically targeting human ovarian cancer cells with minimum side effects against normal cells.

METHODS

The prepared FA-SnO2 NPs were characterized by FT-IR, UV-vis spectroscopy, XRD, SEM and TEM. The inhibition effects of FA-SnO2 NPs against SKOV3 cancer cell were tested by MTT and LDH assay. Apoptosis induction in FA-SnO2 NPs treated SKOV3 cells were investigated using Annexin V/PI, AO/EB and Comet assays and the possible mechanisms of the cytotoxic action were studied by Flow cytometry, qRT-PCR, Immunohistochemistry, and Western blotting analyses. The effects of FA-SnO2 NPs on reactive oxygen species generation in SKOV3 cells were also examined. Additionally, the safety of utilization FA-SnO2 NPs were studied in vivo using Wister rats.

RESULTS

The obtained FA-SnO2 NPs displayed amorphous spherical morphology with an average diameter of 157 nm and a zeta potential value of -24 mV. Comparing to uncoated SnO2 NPs, FA-SnO2 NPs had a superior inhibition effect towards SKOV3 cell growth that was suggested to be mediated through higher reactive oxygen species generation. It was showed that FA-SnO2 NPs increased significantly the % of apoptotic cells in the sub- G1 and G2/M phases with a higher intensity comet nucleus in SKOV3 treated cells. Furthermore, FA-SnO2 NPs was significantly increased the expression levels of P53, Bax, and cleaved Caspase-3 and accompanied with a significant decrease of Bcl-2 in the treated SKOV3 cells.

CONCLUSION

Overall, the results suggested that an increase in cellular FA-SnO2 NPs internalization resulted in a significant induced cytotoxicity in SKOV3 cancer cells in dose-dependent mode through ROS-mediated cell apoptosis that may have occurred through mitochondrial pathway. Additionally, the results confirmed the safety of utilization FA-SnO2 NPs against living systems. So, FA-SnO2 NPs with a specific targeting moiety may be a promising therapeutic candidate for human ovarian cancer.

Biogenic Synthesis of NiO Nanoparticles Using Areca catechu Leaf Extract and Their Antidiabetic and Cytotoxic Effects

Nanoworld is an attractive sphere with the potential to explore novel nanomaterials with valuable applications in medicinal science. Herein, we report an efficient and ecofriendly approach for the synthesis of Nickel oxide nanoparticles (NiO NPs) via a solution combustion method using Areca catechu leaf extract. As-prepared NiO NPs were characterized using various analytical tools such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Visible spectroscopy (UV-Vis). XRD analysis illustrates that synthesized NiO NPs are hexagonal structured crystallites with an average size of 5.46 nm and a hexagonal-shaped morphology with slight agglomeration. The morphology, size, and shape of the obtained material was further confirmed using SEM and TEM analysis. In addition, as-prepared NiO NPs have shown potential antidiabetic and anticancer properties. Our results suggest that the inhibition of α-amylase enzyme with IC 50 value 268.13 µg/mL may be one of the feasible ways through which the NiO NPs exert their hypoglycemic effect. Furthermore, cytotoxic activity performed using NiO NPs exhibited against human lung cancer cell line (A549) proved that the prepared NiO NPs have significant anticancer activity with 93.349 μg/mL at 50% inhibition concentration. The biological assay results revealed that NiO NPs exhibited significant cytotoxicity against human lung cancer cell line (A549) in a dose-dependent manner from 0–100 μg/mL, showing considerable cell viability. Further, the systematic approach deliberates the NiO NPs as a function of phenolic extracts of A. catechu with vast potential for many biological and biomedical applications.

Research progress on the carcinogenicity of metal nanomaterials

With the rapid development of nanotechnology, new nanomaterials with enormous potentials continue to emerge, especially metal nanomaterials. Metal nanomaterials possess the characteristics of metals and nanomaterials, so they are widely used in many fields. But at the same time, whether the use or release of metal nan4omaterials into the environment is toxic to human beings and animals has now attained widespread attention at home and abroad. Currently, it is an indisputable fact that cancer ranks among the top causes of death among residents worldwide. The properties of causing DNA damage and mutations possessed by these metal nanomaterials make them unpredictable influences in the body, subsequently leading to genotoxicity and carcinogenicity. Due to the increasing evidence of their roles in carcinogenicity, this article reviews the toxicological and carcinogenic effects of metal nanomaterials, including nano-metal elements (nickel nanoparticles, silver nanoparticles, and cobalt nanoparticles) and nano-metal oxides (titanium dioxide nanoparticles, silica nanoparticles, zinc oxide nanoparticles, and alumina nanoparticles). This article provides a reference for the researchers and policymakers to use metal nanomaterials rationally in modern industries and biomedicine.

Exposure to variable doses of nickel oxide nanoparticles disturbs serum biochemical parameters and oxidative stress biomarkers from vital organs of albino mice in a sex-specific manner

INTRODUCTION

This study was designed to report the biological effect of nickel oxide nanoparticles (NiO NPs) in albino mice.

MATERIAL AND METHODS

Five weeks old albino mice of both sex were intraperitoneally injected either with 20 mg (low dose) or 50 mg/mL saline/kg body weight (high dose) of NiO NPs for 14 days. Saline-treated controls were maintained in parallel. Complete blood count, selected serum biochemical parameters and oxidative stress biomarkers from vital organs were determined in all subjects.

RESULTS

Male mice treated with NiO NPS had increased blood urea nitrogen, elevated superoxide dismutase (SOD) in liver elevated MDA in liver, kidney and heart and reduced catalase activity in heart and kidney. Female mice treated with NiO NPs had significantly reduced serum albumin and total proteins, SOD in lungs and elevated MDA in liver.

DISCUSSION

We are reporting that intraperitoneal injections of NiO NPs for 14 days drastically affect blood serum parameters and oxidative stress biomarkers from vital organs of albino mice.

CONCLUSION

Toxic effects of NiO NPs were dose and sex dependent and they were more pronounced at higher dose and in male mice.

Cytotoxic, Genotoxic, and Apoptotic Effects of Nickel Oxide Nanoparticles in Intestinal Epithelial Cells

Objectives

The superior properties of nickel oxide-nanoparticles (NiO-NPs) have led to their wide use in various fields. However, there is little comprehensive knowledge about their toxicity, especially after oral exposure. The toxic effect of NiO-NPs of mean size 15.0 nm was investigated in Caco-2 (human intestinal epithelial) cells as no study has been performed on their intestinal toxicity.

Materials and Methods

Following identification of their particle size distribution and cellular uptake potential, the risk of exposure to NiO-NPs was evaluated by cellular morphologic changes, cyto- and genotoxic potentials, oxidative damage, and apoptotic induction.

Results

NiO-NPs induced a 50% reduction in cell viability at 351.6 μg/mL and caused DNA damage and oxidative damage at 30-150 μg/mL. It appears that apoptosis might be a main cell death mechanism in NiO-NP-exposed intestinal cells.

Conclusion

NiO-NPs might be hazardous to the gastrointestinal system. The results should raise concerns about using NiO-NPs in food-contact appliances and about NiO-NP-containing wastes. Further in vivo and in vitro research should be conducted to explain the specific toxicity mechanism of these particles and reduce their risk to humans.

Effect and mechanism of PI3K/AKT/mTOR signaling pathway in the apoptosis of GC-1 cells induced by nickel nanoparticles

Nickel nanoparticles (Ni NPs) have a wide range of application prospects, but there is still a lack of their safety evaluation for the reproductive system. Nowadays, male reproductive health has been widely concerned because of the increasing incidence of male infertility. Studies have shown that Ni NPs can cause male reproductive toxicity. The purpose of this study was to investigate the toxicity of Ni NPs on GC-1 cells, a mouse spermatogonia cell line, and to explore the possible mechanism underlying the induction of apoptosis via PI3K/AKT/mTOR signaling pathway. The cell ultrastructure was firstly observed under a transmission electron microscope. Then, cell proliferation, cycle and apoptosis were detected by CCK-8 and flow cytometry, respectively. Furthermore, the expression levels of related proteins and genes were determined by Western blot and Reverse transcription-polymerase chain reaction, respectively. The results showed that Ni NPs could not only cause changes in cell ultrastructure, decreased survival rate and arrested G1 phase cell cycle, but also activated apoptosis pathway by inhibiting the PI3K/AKT/mTOR signaling pathway. The results of this study provide novel insights to explore the mechanisms of reproductive toxicity of Ni NPs and are of great significance to develop safety evaluation criteria for Ni NPs.

Synergistic antibacterial activity of physical-chemical multi-mechanism by TiO2 nanorod arrays for safe biofilm eradication on implant

Treatment of implant-associated infection is becoming more challenging, especially when bacterial biofilms form on the surface of the implants. Developing multi-mechanism antibacterial methods to combat bacterial biofilm infections by the synergistic effects are superior to those based on single modality due to avoiding the adverse effects arising from the latter. In this work, TiO₂ nanorod arrays in combination with irradiation with 808 near-infrared (NIR) light are proven to eradicate single specie biofilms by combining photothermal therapy, photodynamic therapy, and physical killing of bacteria. The TiO₂ nanorod arrays possess efficient photothermal conversion ability and produce a small amount of reactive oxygen species (ROS). Physiologically, the combined actions of hyperthermia, ROS, and puncturing by nanorods give rise to excellent antibacterial properties on titanium requiring irradiation for only 15 min as demonstrated by our experiments conducted in vitro and in vivo. More importantly, bone biofilm infection is successfully treated efficiently by the synergistic antibacterial effects and at the same time, the TiO₂ nanorod arrays improve the new bone formation around implants. In this protocol, besides the biocompatible TiO₂ nanorod arrays, an extra photosensitizer is not needed and no other ions would be released. Our findings reveal a rapid bacteria-killing method based on the multiple synergetic antibacterial modalities with high biosafety that can be implemented in vivo and obviate the need for a second operation. The concept and antibacterial system described here have large clinical potential in orthopedic and dental applications.

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Various TiO₂ nanostructures were prepared on titanium.

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The TiO₂ nanorod arrays exhibited excellent antibacterial properties under the irradiation of 808 nm NIR light.

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The combined actions of hyperthermia, ROS, and puncturing produced superior antibacterial activity in vitro and in vivo.

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In this antibacterial system, besides the biocompatible TiO₂ nanorod arrays, an extra photosensitizer is not needed.

Advance on toxicity of metal nickel nanoparticles

As a kind of conventional metal nanomaterial, nickel nanoparticles (Ni NPs) have broad application prospects in the fields of magnetism, energy technology and biomedicine and have quickly attracted great interest. The potential negative effects of Ni NPs have also attracted wide attention from some researchers. Studies have shown that Ni NPs cause a variety of toxic effects on cells, animals and humans and have toxic effects of multiple systems such as respiratory system, cardiovascular system and reproductive system. Ni NPs can lead to oxidative stress, apoptosis, DNA damage and inflammation and induce the increase of intracellular reactive oxygen species. The toxicity of Ni NPs is also found to be related to the mitogen-activated protein kinase pathway and the hypoxia inducible factor-1α pathway. Therefore, the toxicity and mechanism of Ni NPs are reviewed in this paper, and the future researches in this field are also proposed.

Styrene Oxide Caused Cell Cycle Arrest and Abolished Myogenic Differentiation of C2C12 Myoblasts

Contaminations of chemicals in foods and drinks are raising public concerns. Among these, styrene, a monomer for plastic production, receives increasing interest due to its ability to leach from the packaging and contaminate in foods and drinks causing many health problems. The present study was designed to investigate the effects of styrene monomer (STR) and its metabolite styrene oxide (STO) on C2C12 myoblast proliferation and differentiation. Based on an MTT assay, both STR and STO showed no cytotoxic effect at 10-100 μM. However, at 50-100 μM STO, but not STR, significantly inhibited cell proliferation. The STO-treated cells were accumulated in S-phase of cell cycles as revealed by flow cytometry. The antioxidant enzyme (catalase and superoxide dismutase) activities and the gene expressing these enzymes of the arrested cells were decreased and ultimately led to nuclear condensation and expression of apoptotic markers such as cleaved caspase-3 and-9, but not cleaved caspase-8. In addition, STO significantly suppressed myogenic differentiation by decreasing both the number and size of differentiated myotubes. Biochemical analysis showed attenuations of total protein synthesis and myosin heavy chain (MHC) protein expression. In conclusion, a metabolite of styrene, STO, leached from plastic packaging of foods and beverages suppressed both myoblast proliferation and differentiation, which would affect skeletal muscle development and regeneration.

The damage of the Watson-Crick base pairs by nickel nanoparticles: A first-principles molecular dynamics study

The nickel nanoparticles are harmful atmospheric pollutants, and the damage caused by them in humans has become a topic of great relevance. In this study we investigate the interaction of the Ni2 and Ni3 clusters with the AT and GC Watson-Crick base pairs in an aqueous medium. Molecular dynamics in combination with density functional theory are employed. A novel method is implemented to create realistic thermodynamic conditions (NVT) in the simulations. The energies, the charges of the interacting compounds, the temperature changes, and the geometric rearrangements are reported. The results show the formation of stable organometallic compounds of the nickel nanoparticles with the DNA nucleic acid bases. In this respect, the biological processes where the DNA is implicated may be altered by the formation of such super-structures.

Supramolecular Insights into Domino Effects of Ag@ZnO-Induced Oxidative Stress in Melanoma Cancer Cells

Recent studies suggest that cancer cell death accompanied by organelle dysfunction might be a promising approach for cancer therapy. The Golgi apparatus has a key role in cell function and may initiate signaling pathways to mitigate stress and, if irreparable, start apoptosis. It has been shown that Golgi disassembly and fragmentation under oxidative stress act as indicators for stress-mediated cell death pathways through cell cycle arrest in the G2/M phase. The present study shows that UV-induced reactive oxygen species (ROS) generation by Ag@ZnO nanoparticles (NPs) transform the Golgi structures from compressed perinuclear ribbons into detached vesicle-like structures distributed in the entire cytoplasm of melanoma cells. This study also demonstrates that Ag@ZnO NP-induced Golgi fragmentation cooccurs with G2 block of cell cycle progression, preventing cells from entering the mitosis phase. Additionally, the increased intracellular ROS production triggered by Ag@ZnO NPs upon UV exposure promoted autophagy. Taken together, Ag@ZnO NPs induce stress-related Golgi fragmentation and autophagy, finally leading to melanoma cell apoptosis. Intracellular oxidative stress generated by Ag@ZnO NPs upon UV irradiation may thus represent a targeted approach to induce cancer cell death through organelle destruction in melanoma cells, while fibroblast cells remained largely unaffected.

Multifunctional Nanorobot System for Active Therapeutic Delivery and Synergistic Chemo-photothermal Therapy

Nanorobots are safe and exhibit powerful functionalities, including delivery, therapy, and diagnosis. Therefore, they are in high demand for the development of new cancer therapies. Although many studies have contributed to the progressive development of the nanorobot system for anticancer drug delivery, these systems still face some critical limitations, such as potentially toxic materials in the nanorobots, unreasonable sizes for passive targeting, and the lack of several essential functions of the nanorobot for anticancer drug delivery including sensing, active targeting, controlling drug release, and sufficient drug loading capacity. Here, we developed a multifunctional nanorobot system capable of precise magnetic control, sufficient drug loading for chemotherapy, light-triggered controlled drug release, light absorption for photothermal therapy, enhanced magnetic resonance imaging, and tumor sensing. The developed nanorobot system exhibits an in vitro synergetic antitumor effect of photothermal therapy and chemotherapy and outstanding tumor-targeting efficiency in both in vitro and in vivo environments. The results of this study encourage further explorations of an efficient active drug delivery system for cancer treatment and the development of nanorobot systems for other biomedical applications.

Long-term effects of sediment dredging on controlling cobalt, zinc, and nickel contamination determined by chemical fractionation and passive sampling

Studies of dredging effectiveness, especially the ones that last for several years, are scarce. In this study, we evaluated effectiveness of dredging performed for six years on controlling cobalt (Co), zinc (Zn), and nickel (Ni) contamination of sediments. High-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) methods were applied to analyze the non-dredged and post-dredging sediments. The soluble and DGT-labile Co and Ni content declined by 22% and 44% (soluble) and by 16% and 26% (labile) in April, July and October in the post-dredging region. In contrast, their concentrations increased by 105% and 9% (soluble) and 322% and 27% (labile) in January. These changes in the dredging effects were caused by the corresponding changes in the reducible and residual fractions of Co and the residual fraction of Ni in sediments in the dredged site, respectively. Soluble and DGT-labile Zn decreased on average by 23% and 29% in July and October and increased on average by 151% and 52% in April and January in the post-dredging region. The different Zn mobility in the post-dredging region was controlled by the reducible fraction of Zn. The results revealed positive influence of dredging engineering in summer, autumn and/or spring and negative one in winter. Therefore, an accurate assessment of dredging effectiveness should take its seasonal variation into consideration.

Mechanisms underlying nickel nanoparticle induced reproductive toxicity and chemo-protective effects of vitamin C in male rats

The purpose of this research is to go a step further study on the reproductive toxicities and the underlying mechanisms induced by nickel nanoparticles (NiNPs), and the possible protective action of vitamin C. Animal experiment was designed according to the one-generation reproductive toxicity standard, and rats were exposed to NiNPs through gavage. Ultrastructural, reactive oxygen species (ROS), oxidant and antioxidant enzymes, and cell apoptosis-related factors in the testicular tissue were analyzed. In contrast with the control group, the activity of surperoxide dismutase (SOD), catalase (CAT) and gonad-stimulating hormone (GSH) was reduced, while the content of nitric oxide (NO), malondialdehyde (MDA) and ROS was increased in the NiNPs treated animals. As the doses of NiNPs increase, the mRNA of apoptotic related factor Caspase-9, Caspase-8 and Caspase-3 showed an obviously upregulation. Protein expression of Bcl-2-associated X Protein (Bax) and apoptosis inducing factor (AIF) was significantly unregulated. After addition of antioxidants-vitamin C, the toxicity was reduced. Injured testicular tissue indicated that NiNPs exposure could damage the reproductive system. Our results suggest that NiNPs induce significant reproductive toxicities. The cellular apoptosis might be induced by caspase family proteinases, but the regulator factor (factor associated suicide (Fas), B-cell lymphoma-2 (Bcl-2), Bax, BH3-interacting domain death agonist (Bid) and AIF protein) might not be involved in this process. Thus, the mechanism of reproductive toxicity of NiNPs on rat testes involves in the induction of oxidative stress, which further results in cell apoptosis. Antioxidants-vitamin C shows a significant inhibition on the reproductive toxicities induced by NiNPs.

High-throughput transcriptomics: Insights into the pathways involved in (nano) nickel toxicity in a key invertebrate test species

Nickel nanoparticles (NiNPs) have an estimated production of ca. 20 tons per year in the US. Nickel has been risk-assessed for long in Europe, but not NiNPs, hence the concern for the environment. In the present study, we focused on investigating the mechanisms of toxicity of NiNPs and the comparison to NiNO₃. The high-throughput microarray for the soil ecotox model Enchytraeus crypticus (Oligochaeta) was used. To anchor gene to phenotype effect level, organisms were exposed to reproduction effect concentrations EC20 and EC50, for 3 and 7 days. Results showed commonly affected pathways between NiNPs and NiNO₃, including increase in proteolysis, apoptosis and inflammatory response, and interference with the nervous system. Mechanisms unique to NiNO₃ were also observed (e.g. glutathione synthesis). No specific mechanisms for NiNPs were found, which could indicate that longer exposure period (>7 days) is required to capture the peak response to NiNPs. A mechanisms scheme is assembled, showing both common and unique mechanisms to NiNO₃ and NiNPs, providing an important framework for further, more targeted, studies.

Necrotic, apoptotic and autophagic cell fates triggered by nanoparticles

Nanomaterials have gained a rapid increase in use in a variety of applications that pertain to many aspects of human life. The majority of these innovations are centered on medical applications and a range of industrial and environmental uses ranging from electronics to environmental remediation. Despite the advantages of NPs, the knowledge of their toxicological behavior and their interactions with the cellular machinery that determines cell fate is extremely limited. This review is an attempt to summarize and increase our understanding of the mechanistic basis of nanomaterial interactions with the cellular machinery that governs cell fate and activity. We review the mechanisms of NP-induced necrosis, apoptosis and autophagy and potential implications of these pathways in nanomaterial-induced outcomes. Abbreviations: Ag, silver; CdTe, cadmium telluride; CNTs, carbon nanotubes; EC, endothelial cell; GFP, green fluorescent protein; GO, graphene oxide; GSH, glutathione; HUVECs, human umbilical vein endothelial cells; NP, nanoparticle; PEI, polyethylenimine; PVP, polyvinylpyrrolidone; QD, quantum dot; ROS, reactive oxygen species; SiO2, silicon dioxide; SPIONs, superparamagnetic iron oxide nanoparticles; SWCNT, single-walled carbon nanotubes; TiO2, titanium dioxide; USPION, ultra-small super paramagnetic iron oxide; ZnO, zinc oxide.

Endophytic Fungus Isolated From Achyrocline satureioides Exhibits Selective Antiglioma Activity-The Role of Sch-642305

Glioblastoma is the most devastating primary brain tumor. Current treatment is palliative, making necessary the development of new therapeutic strategies to offer alternatives to patients. Therefore, endophytes represent an interesting source of natural metabolites with anticancer potential. These microorganisms reside in tissues of living plants and act to improve their growth. Evidence revealed that several medicinal plants are colonized by endophytic fungi producer of antitumor metabolites. Achyrocline satureioides is a Brazilian medicinal plant characterized by its properties against gastrointestinal disturbances, anticancer and antioxidant effects. However, there are no reports describing the endophytic composition of A. satureioides. The present study proposes the isolation of endophytic fungus from A. satureioides, extract preparation, phytochemical characterization and evaluation of its antiglioma potential. Our data showed that crude extracts of endophyte decreased glioma viability with IC50 values of 1.60-1.63 μg/mL to eDCM (dichloromethane extract) and 37.30-55.12 μg/mL to eEtAc (ethyl acetate extract), respectively. Crude extracts induced cell death by apoptosis with modulation of redox status. In order to bioprospect anticancer metabolites, endophytic fungus extracts were subjected to guided fractionation and purification yielded five fractions of each extract. Six of ten fractions showed selective antiproliferative activity against glioma cells, with IC50 values ranged from 0.95 to 131.3 μg/mL. F3DCM (from eDCM) and F3EtAc (from eEtAc) fractions promoted C6 glioma toxicity with IC50 of 1.0 and 27.05 μg/mL, respectively. F3EtAc fraction induced late apoptosis and arrest in G2/M stage, while F3DCM promoted apoptosis with arrest in Sub-G1 phase. Moreover, F3DCM increased antioxidant defense and decreased ROS production. Additionally, F3DCM showed no cytotoxic activity against astrocytes, revealing selective effect. Based on promising potential of F3DCM, we identified the production of Sch-642305, a lactone, which showed antiproliferative properties with IC50 values of 1.1 and 7.6 μg/mL to C6 and U138MG gliomas, respectively. Sch-642305 promoted arrest on cell cycle in G2/M inducing apoptosis. Furthermore, this lactone decreased glioma cell migration and modulated redox status, increasing superoxide dismutase and catalase activities and enhancing sulfhydryl content, consequently suppressing reactive species of oxygen generation. Taken together, these results indicate that metabolites produced by endophytic fungus isolated from A. satureioides have therapeutic potential as antiglioma agent.

Nickel and cobalt resistance properties of Sinorhizobium meliloti isolated from Medicago lupulina growing in gold mine tailing

Sinorhizobium meliloti CCNWSX0020, isolated from root nodules of Medicago lupulina growing in gold mine tailings in the northwest of China, displayed multiple heavy metal resistance and growth promotion of M. lupulina. In our previous work, the expression level of dmeR and dmeF genes were induced by Cu²⁺ through comparative transcriptome approach. Based on protein analysis, the dmeF encoded for a protein which showed a 37% similarity to the cation transporter DmeF of Cupriavidus metallidurans, whereas dmeR encoded transcriptional regulator which was highly homologous with DmeR belonging to RcnR/CsoR family metal-responsive transcriptional regulator. In addition to copper, quantitative real-time PCR analysis showed that dmeR and dmeF were also induced by nickel and cobalt. To investigate the functions of dmeR and dmeF in S. meliloti CCNWSX0020, the dmeR and dmeF deletion mutants were constructed. The dmeF mutant was more sensitive to Co^2 + and Ni^2 + than the wild type strain. Pot experiments were carried out to determine whether the growth of M. lupulina was affected when the dmeF gene was knocked out in the presence of nickel or cobalt. Results indicated that the nodule number of the host plant inoculated with the dmeF deletion mutant was significantly less than the S. meliloti CCNWSX0020 wild-type in the presence of Co^2 + or Ni^2 +. However, when standardized by nodule fresh weight, the nitrogenase activities of nodules infected by the dmeF deletion mutant was similar to nitrogenase activity of the wild type nodule.

Acetyl-l-carnitine attenuates arsenic-induced liver injury by abrogation of mitochondrial dysfunction, inflammation, and apoptosis in rats

Industrial and agricultural developments in recent years have resulted in the excessive discharge of arsenic into the environment, making arsenic toxicity a major worldwide concern. Oxidative stress is considered the primary mechanism for arsenic toxicity. The main objective of this study was to evaluate acetyl-l-carnitine's (ALC) protective ability against the arsenic-induced hepatotoxicity. For this purpose, male Wistar rats were distributed randomly into 5 groups of 8 rats each: control, arsenic (5 mg/kg) and arsenic plus ALC (5 mg/kg; 100, 200, 300 mg/kg). The animals were gavaged for 21 consecutive days. Liver tissue samples were extracted 24 h after the last treatment and were later analyzed for biochemical and histological alterations. The arsenic-induced oxidative damage was confirmed by elevation of malondialdehyde (MDA), a lipid peroxidation byproduct, as well as depletion in physiological antioxidant content such as superoxide dismutase (SOD) and catalase (CAT). Furthermore, alterations in mitochondrial functions including a significant decrease of mitochondrial outer membrane potential and reactive oxygen species (ROS) generation increase, mitochondrial swelling, release of cytochrome c and consequent activation of caspase-3 and caspase-9 and initiation of apoptosis, was observed following arsenic administration. Moreover, the inflammation was confirmed by the overexpression of inflammatory mediators such as NF-ĸB and IL-1 and IL-6. The present study demonstrated that ALC ameliorates arsenic-induced oxidative damage, mitochondrial dysfunction, apoptosis, inflammation and histological damage. ALC's protective features against arsenic hepatotoxicity may be due to this agent's antioxidant and anti-inflammatory properties as well as its stabilizing effects on mitochondrial function.

Role of oxidative stress in liver toxicity induced by nickel oxide nanoparticles in rats

The aim of the present study was to explore the role of oxidative stress in liver toxicity induced by nickel oxide nanoparticles (nano‑NiO) in rats. Male Wistar rats received saline (control), nano‑NiO [0.015, 0.06 or 0.24 mg/kg body weight (b.w.)] or micro‑NiO (0.24 mg/kg b.w.) by intratracheal instilling twice a week for 6 weeks. Liver tissues were then collected and examined for biomarkers of nitrative and oxidative stress, as well as mRNA expression of heme oxygenase (HO)‑1 and metallothionein (MT)‑1. The results demonstrated that the NiO exposure groups had increased liver wet weight and coefficient to body weight, as well as liver pathological changes, evidenced as cellular edema, hepatic sinus disappeara-nce and binucleated hepatocytes. The activities of total nitric oxide synthase and inducible nitric oxide synthase, and the nitric oxide content, were increased in the 0.24 mg/kg nano‑NiO group compared with the control group. The MT‑1 mRNA expression levels were downregulated, while HO‑1 mRNA was upregulated in the 0.24 mg/kg nano‑NiO exposure group compared with the control group. In addition, abnormal changes of hydroxyl radical, lipid peroxidation, catalase, glutathione peroxidase, total superoxide dismutase and total antioxidative capacity were observed in the liver tissues of the 0.24 mg/kg nano‑NiO exposure group, compared with the control group. The present results therefore indicated that nano‑NiO‑induced liver toxicity may be associated with nitrative and oxidative stress in rats.

Cytotoxic effect of albumin coated copper nanoparticle on human breast cancer cells of MDA-MB 231

PURPOSE

The aim of this study was to design a new nanocomposite that would have high cytotoxicity against invasive breast cancer cells and minimum side effects on normal cells.

METHODS

An albumin nano-carrier for delivery of CuNPs was developed. The ACuNPs formation was characterized by TEM, DLS and UV-Vis, fluorescence and circular dichroism spectroscopy. The cytotoxic efficacy of the ACuNPs against human breast cancer cells (MDA-MB 231) and normal cells (MCF-10A) was compared using a standard MTT assay. The mechanism of cell death induced by ACuNPs was considered by inverted and fluorescent microscopy, flow cytometry and gel electrophoresis. The effects of compounds on ROS generations in MDA-MB 231 cells were also studied.

RESULTS

It was found that the resulted ACuNPs with a diameter of 62.7 nm and zeta potential of about -10.76 mV, are suitable for extravasation into tumor cells. In ACuNPs, the 90% of the secondary structure and almost all the tertiary structure of albumin remained intact. Comparing to CuNPs, ACuNPs could significantly suppress the viability of cancer cells while they were less toxic on normal cells. Compared with the untreated cells, the MDA-MB 231 cell line showed higher levels of ROS production after treatment with ACuNPs. The increase in ROS production after 24 hours indicated that ACuNPs induce apoptosis.

CONCLUSIONS

The ACuNPs characteristics such as intact structure of albumin, high toxicity against cancer cells comparing to normal cells and apoptosis induction as the mechanism of cell death, revealed that this nanocomposite is a good candidate to be used as a chemotherapeutic agent against invasive breast cancer cells.

Nickel Oxide Nanoparticles Induce Oxidative DNA Damage and Apoptosis in Kidney Cell Line (NRK-52E)

Increasing use of nickel oxide (NiO) nanoparticles in different applications results in high occupational and environmental exposure to them. However, the effect of NiO nanoparticles on human health is still poorly documented. It was aimed to investigate the toxic potentials of NiO nanoparticles on NRK-52E kidney epithelial cells. The following assays were used: the nanoparticle characterization by transmission electron microscopy (TEM) and dynamic light scattering (DLS); the determination of cellular uptake and morphologic changes by TEM and inductively coupled plasma-mass spectrometry (ICP-MS); MTT and neutral red uptake (NRU) assays for cytotoxicity; comet assay for genotoxicity; the determination of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), protein carbonyl (PC) and glutathione (GSH) levels by enzyme-linked immune sorbent assays (ELISA) for the potential of oxidative damage; and Annexin V-FITC apoptosis detection assay with propidium iodide (PI) for apoptosis. The nanoparticles were taken up by the cells and induced dose-dependent DNA damage by comet assay and oxidative damage evidenced by increasing levels of MDA, 8-OHdG, PC and depletion of GSH. At ≥294.0 μg/mL concentration, NiO nanoparticles caused 50% inhibition in cell viability by the cytotoxicity assays. Also, they showed apoptotic/necrotic effects on the cells as well as some morphological changes. We have indicated that their cellular damage effects should raise concern about the safety associated with their applications in consumer products.

Nano NiO induced liver toxicity via activating the NF-κB signaling pathway in rats

Studies have demonstrated that nano NiO could induce liver toxicity in rats, but its mechanism remains unclear. This study aimed to explore the role of the NF-κB signaling pathway in rat liver toxicity after nano NiO exposure. Male Wistar rats were exposed to nano NiO (0.015, 0.06 and 0.24 mg per kg b.w.) and micro NiO (0.24 mg per kg b.w.) by intratracheal instillation twice a week for 6 weeks. To investigate the liver toxicity induced by nano NiO, the indicators of liver function and inflammatory response were detected, and the histopathological changes were observed. The levels of NF-κB signaling pathway related gene and protein expression were examined using RT-qPCR and western blot techniques in the liver tissue. The results showed that the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma-glutamyltranspeptidase (GGT) increased after nano NiO exposure. Cellular edema, hepatic sinus disappearance, and neutrophil and lymphocyte infiltration were observed. Nano NiO increased the concentrations of pro-inflammatory cytokines (IL-1β and IL-6), but decreased the levels of anti-inflammatory cytokines (IL-4 and IL-10). It also induced the upregulation of TNF-α, NF-κB-inducible kinase (NIK), IκB kinase alpha (IKK-α) and NF-κB mRNA, while inducing the downregulation of the inhibitor kappa B (IκB) alpha. In addition, we found that the protein content of NIK, IKK-α, p-IKK-α, p-IκB-α and NF-κB was elevated, whereas that of IκB-α was reduced. The results indicated that the NF-κB signaling pathway played an important role in rat liver toxicity induced by nano NiO.

Nickel oxide nanoparticles are highly toxic to SH-SY5Y neuronal cells

Nickel oxide nanoparticles (NiO-NPs) are used in many industrial sectors including printing inks, ceramics and catalysts, and electrical and electronics industry because of their magnetic and optical properties. However, there has been still a serious lack of information about their toxicity at the cellular and molecular levels on nervous system. For that, we aimed to investigate the in vitro toxic potentials of NiO-NPs in neuronal (SH-SY5Y) cells. The particle characterisation, cellular uptake and morphological changes were determined using Transmission Electron Microscopy, dynamic light scattering and Inductively Coupled Plasma-Mass Spectrometry. Then, the cytotoxicity was evaluated by MTT and neutral red uptake assays, the genotoxicity by comet assay, the oxidative potentials by the determination of malondialdehyde, 8-hydroxy deoxyguanosine, protein carbonyl, and glutathione levels with Enzyme-Linked Immune Sorbent Assays, and the apoptotic potentials by Annexin V-FITC apoptosis detection assay with propidium iodide. According to the results, it was observed that NiO-NPs (15.0 nm ± 4.2-38.1 nm); (i) were taken up by the cells in concentration dependent manner, (ii) caused 50% inhibition in cell viability at ≥229.34 μg/mL, (iii) induced some morphological changes, (iv) induced dose-dependent DNA damage (3.2-11.0 fold) and apoptosis (80-99%), (v) significantly induced oxidative damage. In conclusion, our results support the hypothesis that NiO-NPs affect human health especially neuronal system negatively and should raise the concern about the safety associated with their applications in consumer products.

Cytotoxic response of platinum-coated gold nanorods in human breast cancer cells at very low exposure levels

Because of unique optical behavior gold nanorods (GNRs) have attracted attention for the application in biomedical field such as bio-sensing, bio-imaging and hyperthermia. However, toxicological response of GNRs is controversial due to their different surface coating. Therefore, a comprehensive knowledge about toxicological profile of GNRs is necessary before their biomedical applications. First time, we investigated the toxic response of GNRs coated with platinum (GNRs-Pt) in human breast carcinoma (MCF-7) cells. Platinum coating further improves the optical and catalytic properties of GNRs. Assays such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT), neutral red uptake (NRU) and lactate dehydroganase (LDH) assays have shown that GNRs-Pt induced cytotoxicity at very low exposure levels (0.1-0.8 μg mL^-1 ). Accumulation of cells in SubG1 phase and low mitochondrial membrane potential (JC-1 probe) in treated cells suggest that GNRs-Pt induced cell death via apoptotic pathway. Quantitative real-time PCR data demonstrated that mRNA expression of apoptotic genes (bax, caspase-3 and caspase-9) were up-regulated while anti-apoptotic gene bcl-2 was down-regulated in cells exposed to GNRs-Pt. We further observed the higher activity of caspase-3 and caspase-9 enzymes in GNRs-Pt treated cells supporting mRNA data. Moreover, N-acetyl cysteine (NAC) significantly attenuated the ROS generation and cytotoxicity induced by GNRs-Pt in MCF-7 cells suggesting that ROS might plays a crucial role in GNRs-Pt induced toxicity. This study warns of possible toxicity of GNRs even at very low exposure levels. Further investigations needed to explore potential mechanisms of this low dose toxicity phenomenon. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1344-1356, 2016.