Different Concentrations Of ZnO NPs Research Articles

The Effect of Zinc Oxide Nanoparticles (ZnO NPs) on Vigna mungo L. Seedling Growth and Antioxidant Activity

Aim:The purpose of this study was to test the phytotoxicity effect of ZnONPs on Vigna mungo L. seedling growth and antioxidant activity.Methods:Vigna mungo L. Seeds were treated with to a wide range of ZnO NPs ranging 5 to25mg/100ml for 8hours. Vigna mungo seeds that were soaked in ZnO NPs solution were sown in pots (20 cm × 40 cm) filled with red soil and a layer of coco peat. The effect of ZnO NPs on morphological, biochemical and antioxidant activity in Vigna mungo L. plants was investigated after 15,30,45 and 60 days.Results:The impact of ZnO NPs on plant growth characteristics and biochemical changes in Vigna mungo L. plants was investigated after 15,30,45 and 60 days. The ZnONPs exposure significantly enhanced germination percentage by 111.3% but root length (75.25%), shoot length (89.81%), number of leaves (91.66%), length of leaves (76%), width of leaves (67.27%), fresh weight of plant (27.96%) and dry weight of plant (28.23%) decreased in the treated plants after 60 days exposure to 25mg/100ml compared to the untreated control. Interestingly, treated plants after 60 days exposure to 25mg/100ml increased significantly the chlorophyll (115.0%), reducing sugars (244.4%), total sugars (212.72%) protein (181.8%). Treatment to Vigna mungo L. seeds with ZnONPs has been found to induce the activities of antioxidant enzymes such as Guaiacol peroxidase, Glutathione Reductase, Catalase and increase in the ascorbic acid and hydrogen peroxide contents. TEM images revealed that the aggregated ZnO NPs to be deposited inside the seed.Conclusion:Vigna mungo seeds treated with different concentrations of ZnO NPs showed decreased root growth and increased germination index, shoot and leaf growth. There was a significant change in Glutathione reductase, Guaiacol peroxidase and Catalase activity and ascorbic acid and hydrogen peroxide of Vigna mungo exposed to ZnONPs. Aggregated nanoparticles penetration into the intracellular region of the seed was observed.A complete study on the toxic effects of ZnO NPs can help significantly in the safe disposal of ENPs for the reduction of adverse effects in both environmental and agricultural systems.

Green Synthesized Zinc Oxide Nanoparticles as Feed Additives to Improve Growth, Biochemical, and Hematological Parameters in Freshwater Fish Labeo rohita.

Zinc deficiency in aquatic animals affects the biological processes and physiological functions. Thus, the supplement of ZnONPs can be used as an alternative method to overcome zinc deficiency. Nanoparticles have the potential to enhance the growth and health of the fish. The main aim of this study is to evaluate the growth efficacy of ZnONP-supplemented diet with fingerlings of Labeo rohita. The green synthesized ZnONPs were characterized by ultraviolet-visible (UV-Vis) spectroscopy, Fourier transformer infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Different concentrations of ZnONPs (5, 7.5, and 10 mg/kg) were administered in the basal diet of freshwater fish Labeo rohita for 45 days to observe the growth and metabolic functions of the body. However, the fish fed with 10 mg/kg ZnONP-supplemented diet shows that the growth performance was highly increased followed by 7.5 mg/kg and 5 mg/kg ZnONPs when compared with the control. The biochemical, hematological, and digestive enzyme activities were also significantly increased with different concentrations of ZnONPs. The effects of zinc oxide nanoparticles show the higher improvement of growth and metabolic functions in Labeo rohita. These results suggest that the nanotechnology could apply for feed formulation technology and pave the way for the dietary supplementation of zinc oxide nanoparticles as safe ingredients for aquatic animals to overcome the zinc deficiency.

ZnO nanoparticles inhibit the activity of Porphyromonas gingivalis and Actinomyces naeslundii and promote the mineralization of the cementum

BackgroundZinc oxide nanoparticles (ZnONPs) have been widely studied as bactericidal reagents. However, it is still challenging to use ZnONPs as a root canal sealant to eliminate infecting microorganisms in the root canal system. This study aimed at understanding the antibacterial and biofilm effects of ZnONPs in the infected root canal and their effect on cell function.MethodsThis study aimed to develop a better understanding of the antibacterial effects of ZnONPs in the infected root canal and their effect on cell function. Experiments were performed in two stages; the first stage included inhibition zone tests and the minimum inhibitory concentration (MIC) test, which were performed to examine the antibacterial activity of ZnONPs against Porphyromonas gingivalis (P. gingivalis) and Actinomyces Naeslundii (A. naeslundii) bacteria in vitro. ZnONPs were further evaluated for their biocompatibility using normal mouse NIH3T3 and OCCM-30 cells by the cell-based MTT assay. In addition, the influence of ZnONPs on matrix metalloproteinases in NIH3T3 cells and their inhibiting factors (Mmp13 and Timp1) were measured using the real-time PCR technique and western blot method.ResultsThe MIC of ZnONPs against P. gingivalis and A. naeslundii were confirmed to be 10 μg/mL and 40 μg/mL, respectively. The MTT assay showed that ZnONPs were nontoxic. The RT-PCR and western blotting results showed that Mmp13 was downregulated and Timp1 expression was increased. Meanwhile, ZnONPs were shown to increase the expression of the OCCM-30 osteogenesis-related factors Bsp and Runx2. Finally, there was no significant change in the morphology of NIH3T3 and OCCM-30 cells after the addition of different concentrations of ZnONPs for different periods of time.ConclusionZnONPs have excellent antibacterial activity against P. gingivalis and A. naeslundii and have low cell cytotoxicity in vitro.

Antioxidant activity of endogenously produced nitric oxide against the zinc oxide nanoparticle-induced oxidative stress in primary hepatocytes of air-breathing catfish, Clarias magur

The facultative air-breathing magur catfish (Clarias magur) regularly encounter various environmental challenges including the exposure to nanomaterials discarded as industrial wastes in water bodies. The present investigation aimed at determining the possible ZnO NP-induced oxidative stress and also the antioxidant strategy of nitric oxide (NO), generated endogenously, in primary hepatocytes of magur catfish. Exposure of primary hepatocytes to different concentrations of ZnO NPs (5 and 10 μg/mL) led to a sharp rise of intracellular concentrations of hydrogen peroxide (H2O2) and malondialdehyde (MDA) within 6 h, which decreased gradually at later stages. This phenomenon was accompanied by an initial decrease of superoxide dismutase (SOD) and catalase (CAT) activities, the expression of their corresponding genes and the enzyme protein levels, with a subsequent significant increase of all these parameters at later stages. Most interestingly, exposure to ZnO NPs also stimulated the NO production by the primary hepatocytes as a consequence of induction of inducible nitric oxide synthase (iNOS) activity, higher expression of nos2 gene and iNOS protein. Furthermore, when the NO production by the hepatocytes was inhibited by either aminoguanidine (inhibitor for iNOS) or BAY (inhibitor for NFκB) in the presence of ZnO NPs, the intracellular concentrations of H2O2 and MDA was significantly elevated. This elevation was accompanied by a subsequent decrease of sod and cat genes expression, thereby suggesting that the inhibition of NO production leads to oxidative stress. Thus, it is believed that the magur catfish uses the strategy of stimulation of endogenous NO production by inducing the nos2 gene and simultaneous NO-mediated induction of sod and cat genes to defend against the NP-induced oxidative stress. It is the first report of such NO-mediated antioxidant strategy in any teleost fish to defend against the NP-induced oxidative stress and corresponding cellular damages.

Molecular and Biochemical Evidences for Beneficial Effects of Zinc Oxide Nanoparticles in Modulation of Chlorpyrifos Toxicity in Human Lymphocytes.

Chlorpyrifos (CP), an acetylcholinesterase (AChE) inhibitor, is used throughout the world as an insecticide in agriculture and an eradicating agent for termites around homes. In the present study, we examined the protective role of zinc oxide nanoparticles (ZnO NPs) in human CP-treated lymphocytes. Lymphocytes isolated by Ficoll and exposed to 75 µg/mL CP either alone or in combination with logarithmic doses of ZnO NPs (0/1, 1, 10, 100 µg/mL). After a 3-day incubation period, the viability and oxidative stress markers were determined. Then, the levels of tumor necrosis factor-α (TNF-α), as an inflammatory index along with AChE activity and cell death were evaluated. Our results showed that incubation with CP significantly increases the percent of cell death, activities of caspase-3 and -9, level of TNF-α and also promotes the levels of biomarkers which play important role in oxidative stress. On the other hand, the activity of AChE and levels of the total antioxidant power (TAP) decreased in CP-treated lymphocytes. In contrast, lymphocytes treated with different concentrations of ZnO NPs showed a significant decrease in the percent of mortality as well as the levels of TNF-α, as compared with CP-treated lymphocytes. Besides, ZnO NPs increased the levels of AChE and TAP at 1 µg/mL. In conclusion, the results indicate the protective effects of ZnO NPs in the prevention of cytotoxic activity of CP in the lymphocytes.

Zinc Oxide Nanoparticles Influence Microflora in Ileal Digesta and Correlate Well with Blood Metabolites.

Zinc oxide nanoparticles (ZnO NPs) are used widely in consumer and industrial products, however, their influence on gut microbiota and metabolism and their mutual interactions are not fully understood. In this study, the effects of ZnO NPs on ileal bacterial communities, plasma metabolites, and correlations between them were investigated. Hens were fed with different concentrations of ZnO NPs [based on Zn; 0 mg/kg (control), 25 mg/kg, 50 mg/kg, and 100 mg/kg] for 9 weeks. Subsequently, ileal digesta and blood plasma were collected for analysis of microflora and metabolites, respectively. The V3-V4 region of the 16S rRNA gene of ileal digesta microbiota was sequenced using the Illumina HiSeq 2500 platform. The predominant bacterial community in the ileum belongs to the phylum Firmicutes. The richness of the bacterial community was negatively correlated with increasing amounts of ZnO NPs (r = -0.636, P < 0.01); when ZnO NP levels were at 100 mg/kg, microbiota diversity was significantly decreased (P < 0.05). The community structure determined by LEfSe analysis indicated that Bacilli, Fusobacteria, and Proteobacteria were changed, and Lactobacillus was reduced by ZnO NPs. Moreover, metabolism as analyzed by nuclear magnetic resonance (NMR) indicated that glucose, some amino acids, and other metabolites were changed by ZnO NPs. Choline, lactate, and methionine were positively correlated with bacterial richness. In summary, ZnO NPs could influence the levels of microflora in ileal digesta, particularly Lactobacillus. Furthermore, the richness of the microbiota was related to changes in choline, lactate, and methionine metabolism.

ZnO nanoparticles (ZnO-NPs) and their antifungal activity against coffee fungus Erythricium salmonicolor

In this work, a methodology of synthesis was designed to obtain ZnO nanoparticles (ZnO NPs) in a controlled and reproducible manner. The nanoparticles obtained were characterized using infrared spectroscopy, X-ray diffraction, and transmission electron microscopy (TEM). Also, we determined the antifungal capacity in vitro of zinc oxide nanoparticles synthesized, examining their action on Erythricium salmonicolor fungy causal of pink disease. To determine the effect of the quantity of zinc precursor used during ZnO NPs synthesis on the antifungal capacity, 0.1 and 0.15 M concentrations of zinc acetate were examined. To study the inactivation of the mycelial growth of the fungus, different concentrations of ZnO NPs of the two types of synthesized samples were used. The inhibitory effect on the growth of the fungus was determined by measuring the growth area as a function of time. The morphological change was observed with high-resolution optical microscopy (HROM), while TEM was used to observe changes in its ultrastructure. The results showed that a concentration of 9 mmol L−1 for the sample obtained from the 0.15 M and at 12 mmol L−1 for the 0.1 M system significantly inhibited growth of E. salmonicolor. In the HROM images a deformation was observed in the growth pattern: notable thinning of the fibers of the hyphae and a clumping tendency. The TEM images showed a liquefaction of the cytoplasmic content, making it less electron-dense, with the presence of a number of vacuoles and significant detachment of the cell wall.

Insecticidal effects of zinc oxide nanoparticles and Beauveria bassiana TS11 on Trialeurodes vaporariorum (Westwood, 1856) (Hemiptera: Aleyrodidae)

Greenhouse whitefly, Trialeurodes vaporariorum is a major pest of horticultural and ornamental plants and is usually controlled with insecticides or biological control agents. In the current study, we examined the effects of synthesized zinc oxide nanoparticles (ZnO NPs) and Beauveria bassiana TS11 on T. vaporariorum adults. ZnO NPs were synthesized by precipitation method. Field emission scanning electron microscope images indicated that ZnO NPs were non-compacted uniformly. X-ray diffraction results confirmed the hexagonal wurtzite structure of ZnO NPs. Fourier transform infrared analysis showed an intense absorption peak at a range of 434-555 cm-1 related to Zn-O bond. In bioassays, adults were exposed to different concentrations of ZnO NPs (3, 5, 10, 15, 20 mg l-1) and fungi (104, 105, 106, 107, 108 spores ml-1). LC50 values for ZnO NPs and fungi were 7.35 mg l-1and 3.28×105 spores ml-1, respectively. Mortality rates obtained with ZnO NPs and fungi at the highest concentration were 91.6 % and 88.8 %, respectively. The results indicate a positive effect of ZnO NPs and B. bassiana TS11on adults. The current study was conducted under laboratory conditions, therefore, more studies are needed in field.

Chronic exposure to zinc oxide nanoparticles increases ischemic-reperfusion injuries in isolated rat hearts

The use of zinc oxide nanoparticles (ZnO NPs) in numerous products is increasing, although possible negative implications of their long-term consumption are not known yet. Our aim was to evaluate the chronic, 6-week oral exposure to two different concentrations of ZnO NPs on isolated rat hearts exposed to ischemic-reperfusion injury and on small intestine morphology. Wistar rats of both sexes (n = 18) were randomly divided into three groups: (1) 4 mg/kg ZnO NPs, (2) 40 mg/kg ZnO NPs, and (3) control. After 6 weeks of treatment, the hearts were isolated, the left ventricular pressure (LVP), the coronary flow (CF), the duration of arrhythmias and the lactate dehydrogenase release rate (LDH) were measured. A histological investigation of the small intestine was performed. Chronic exposure to ZnO NPs acted cardiotoxic dose-dependently. ZnO NPs in dosage 40 mg/kg maximally decreased LVP (3.3-fold) and CF (2.5-fold) and increased the duration of ventricular tachycardia (all P < 0.01) compared to control, whereas ZnO NPs in dosage 4 mg/kg acted less cardiotoxic. Goblet cells in the small intestine epithelium of rats, treated with 40 mg ZnO NPs/kg, were enlarged, swollen and numerous, the intestinal epithelium width was increased. Unexpectedly, ZnO NPs in both dosages significantly decreased LDH. A 6-week oral exposure to ZnO NPs dose-dependently increased heart injuries and caused irritation of the intestinal mucosa. A prolonged exposure to ZnO NPs might cause functional damage to the heart even with exposures to the recommended daily doses, which should be tested in future studies.

Sublethal effects of zinc oxide nanoparticles on male reproductive cells

Environmental exposure to nanomaterials is inevitable as nanomaterials become part of our daily life, and as a result, nanotoxicity research is gaining attention. Most investigators focused on the effects of zinc oxide nanoparticles (ZnO NPs) on human health, while limited information was available on the male reproductive system. Herein, mouse Sertoli cell line (TM-4) and spermatocyte cell line (GC2-spd) were used as in vitro models to explore the reproductive effects of ZnO NPs at sublethal dose and its underlying mechanisms. Cells were treated with different concentrations of ZnO NPs. By cell viability assay, a dose of 8μg/mL was found as a sublethal dose and increased the ROS levels in both cells. The decreased glutathione level and increased MDA level were also found in ZnO NPs treated group. In TM4 cells, the expressions of BTB proteins (ZO-1, occludin, claudin-5, and connexin-43) were lower in the ZnO NPs group. The increased cell permeability and increased TNF-α secretion were also observed in ZnO NPs group. In GC2-spd cells, S phase arrest and DNA damage occurred in ZnO NPs group, which could be partially rescued by NAC. Our findings demonstrated that exposure to ZnO NPs induced ROS generation, caused DNA damage of germ cells, and down-regulated the expression of BTB proteins in Sertoli cells which could compromise the integrity of the blood-testis barrier. All these contributed to the male reproductive cytotoxic effects of ZnO NPs that could be partially rescued by anti-oxidants.

Zinc oxide nanoparticles induce renal toxicity through reactive oxygen species

Nanoparticles of zinc oxide (ZnO NPs) are applied in many fields nowadays. Consequently, concerns have been raised about its potential harmful effects. The present study focuses on its toxic effect on podocytes and rats. In vitro study, podocytes were treated with different concentrations of ZnO NPs (10, 50 and 100 μg/ml), the viability of cells was decreased as time prolonged according to MTT assay. Meantime, flow cytometry analysis indicated that ZnO NPs induced intracellular accumulation of reactive oxygen species (ROS) and apoptosis. The measurement of superoxide dismutase (SOD) and malondialdehyde (MDA) showed that ZnO NPs decreased SOD level and increased MDA level. Interestingly, pretreatment with N-mercaptopropionyl-glycine, known as a type of ROS scavenger, could inhibit podocyte apoptosis induced by ZnO NPs. Meantime, a loss of nephrin can be detected, which may result in a direct damage to slit diaphragms. In vivo study, adult male Wistar rats were administrated with 3mg/kg/day ZnO NPs for 5 days, body weight and kidney index were significantly reduced. In addition, ZnO NPs decreased the activity of catalase and SOD in kidney cortex in vivo. It could be concluded that ZnO NPs present toxic effect on podocytes and Wistar rats, which was related with oxidative stress.

The Effect of Zinc Oxide Nanoparticles on Streptococcus Mutans of Human Saliva : In Vitro Study

Background: Nanotechnology represents a new science that promises to provide a broad range of uses and improved technologies for biological and biomedical applications. One of the reasons behind the intense interest is that nanotechnology permits synthesis of materials that have structure is less than 100 nanometers. The present work revealed the effect of zinc oxide nanoparticles (ZnO NPs) on Streptococcus mutans of Human Saliva in comparison to de-ionized water. Materials and methods: Streptococcus mutans were isolated from saliva of forty eight volunteers of both sexes their age range between 18-22 years and then purified and diagnosed according to morphological characteristic and biochemical tests. Different concentrations of ZnO NPs were prepared from the stock solution; all the experiments were conducted in vitro. Disk diffusion method was used to study the sensitivity of Streptococcus mutans to different concentrations of zinc oxide nanoparticles in comparison to effect of de-ionized water. Results: Streptococcus mutans were sensitive to concentrations (0.05, 0.1, 0.5, 1, 3 and 5.8) mg / ml of the zinc oxide nanoparticles solution in comparison to de-ionized water, revealing a highly significant difference in all concentrations except for concentration (0.01) mg / ml which was showed no significant difference in comparison to de-ionized water. Conclusion: This study revealed that zinc oxide nanoparticles were effective against Streptococcus mutans.

Zinc oxide nanoparticles induce eosinophilic airway inflammation in mice

Zinc oxide nanoparticles (ZnO NPs) have been widely used in industry. The metal composition of PM2.5 might contribute to the higher prevalence of asthma. To investigate the effects of ZnO NPs on allergic airway inflammation, mice were first exposed to different concentrations of ZnO NPs (0.1mg/kg, 0.5mg/kg) or to a combination of ZnO NPs and chicken egg ovalbumin (OVA) by oropharyngeal aspiration on day 0 and day 7 and then were sacrificed 5 days later. The subsequent time course of airway inflammation in the mice after ZnO NPs exposure was evaluated on days 1, 7, and 14. To further determine the role of zinc ions, ZnCl2 was also administered. The inflammatory cell count, cytokine levels in the bronchoalveolar lavage fluid (BALF), and lung histopathology were examined. We found significant neutrophilia after exposure to high-dose ZnO NPs on day 1 and significant eosinophilia in the BALF at 7 days. However, the expression levels of the T helper 2 (Th2) cytokines IL-4, IL-5, and IL-13 increased significantly after 24h of exposure to only ZnO NPs and then decreased gradually. These results suggested that ZnO NPs could cause eosinophilic airway inflammation in the absence of allergens.

Effects of pH and Temperature on Antibacterial Activity of Zinc Oxide Nanofluid Against Escherichia coli O157: H7 and Staphylococcus aureus.

Background:Zinc oxide nanoparticles (ZnO NPs) are known as one of the important inorganic materials used in research and health-related applications with effective antibacterial activities. Although the toxic effects of ZnO NPs have already been evaluated, more information is required to understand the possible mechanisms.Objectives:The aim of the present study was to determine the influences of pH and temperature on antibacterial activity of ZnO NPs against some strains of pathogenic bacteria. Identifying the interrelationship between toxicity and cultural conditions helps us to have a better understanding of the optimum reaction conditions for maximum antimicrobial activity.Materials and Methods:ZnO NPs were prepared and characterized and then dispersed in glycerol with the help of ammonium citrate as the dispersant. The antibacterial tests were performed by measuring the growth of Escherichia coli O157:H7 and Staphylococcus aureus with different concentrations of ZnO NPs in glycerol. All the experiments were conducted at different incubation temperatures (25-42°C) and pH levels (4-10 for E. coli O157:H7 and 5-10 for S. aureus).Results:The results showed that ZnO nanofluid have antibacterial activity against E. coli O157:H7 and S. aureus and the inhibitory effect increases with increasing the nanofluid concentration. The experiments showed that the antibacterial activity of ZnO NPs was influenced by temperature and pH. Higher antibacterial activity was observed at acidic pH levels with the maximum toxicity at pH = 4 and pH = 5 for E. coli O157: H7 and S. aureus, respectively. By raising the temperature, the toxicity of ZnO nanofluid increased, with the highest antibacterial activity at 42°C for both bacterial types in comparison with positive controls under the same conditions.Conclusions:Analysis of the results demonstrated that exposure media of ZnO NPs and cultural factors play a role in their cytotoxic effects. It could be attributed to the principal mechanism at different reaction conditions.

Evaluation of growth and biochemical indicators of Salvinia natans exposed to zinc oxide nanoparticles and zinc accumulation in plants

The adverse effects of zinc oxide nanoparticles (ZnO NPs) with an average diameter of 25nm on the aquatic plant Salvinia natans (L.) All. were determined. Growth, superoxide dismutase (SOD) activity, catalase (CAT) activity, peroxidase activity, and chlorophyll content of the plants were measured after 7days of exposure to different concentrations of ZnO NPs (1 to 50mgL(-1)). The particle distribution in the culture medium (without plants) during the first 24h was determined using a Nanotrac 250 particle analyzer. We also investigated the zinc accumulation in leaves and roots of the plant after 7days of exposure. Exposure to 50mgL(-1) ZnO NPs significantly increased SOD and CAT activities (P < 0.05) and significantly depressed photosynthetic pigments (P < 0.05). However, plant growth was not significantly affected (P > 0.05). NPs completely precipitated at the bottom of the container at 8h except for the portions of dissolution and aggregation on the roots. ZnO NPs at a concentration of 50mgL(-1) can adversely affect S. natans, and their stress is affected by their aggregation and dissolution.