Effects Of AgNPs Research Articles

Investigation of Antioxidant and Cytotoxicity Effects of Silver Nanoparticles Produced by Biosynthesis Using Lactobacillus gasseri.

The biosynthesis of silver nanoparticles (AgNPs) is a new approach in nanotechnology which was optimistically implemented in medicine, food control, and pharmacology. The present study aimed to investigate the antioxidant and cytotoxicity effects of AgNPs produced by Lactobacillus gasseri filtrate. Also, changing color from yellow to brown confirmed the production of AgNPs. AgNPs were characterized using ultraviolet-visible spectroscopy, FE-SEM, and Fourier Transform Infrared Spectroscopy (FTIR). The antioxidant activity of AgNPs was tested using the DPPH assay. The scavenging test for DPPH showed 19.3%, 32.6%, 47.6%, 72%, 85.3% at concentrations (6.25, 12.5, 25, 52, 100) µg/ml, respectively, which proved that the scavenging percentage increased with increasing concentration. The effect of AgNPs on the chromosomal pattern was also studied. The results of the experiment of AgNPs against SK-GT-4 cancer cells showed the toxic activity of the used particles against the strains of these human esophageal cancer cells and failed to affect normal cells.

Mycosynthesis of Silver Nanoparticles by Candida albicans Yeast and its Biological Applications.

This study conducted a mycosynthesis of silver nanoparticles (AgNPs) by Candida albicans supernatant. The mycosynthesized AgNPs were identified by color visualization, ultraviolet-visible (UV) spectroscopy device, X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDX), field emission scanning electron microscope (FESEM), and zeta potential analysis. The UV-Vis spectroscopy examination has shown the highest absorbance (λmax) at the wavelength of 429 nanometers, which was the indicator of the creation of AgNPs. Furthermore, XRD showed the crystalline structure of AgNPs, and EDX revealed the weight percentage of silver atoms in the sample (82.4%). According to the FESEM, the morphology of AgNPs was spherical, and its size was 40.19 nanometers. Zeta potential analysis indicated that AgNPs were middling stable in the solution, and the zeta potential of AgNPs mycosynthesized by C. albicans was-23.02 mV. The cytotoxic effect of AgNPs against a human colon cancer cell line using MTT assay has shown the presence of toxic action against the cells, and no cytotoxic effect appears on the normal cells. The antioxidant activity of AgNPs using DPPH assay demonstrated 17.0%, 29.3%, 48.3%, 67.6%, and 83.6% at concentrations of 6.25, 12.5, 25, 50, and 100 µg/ml, respectively. The impact of AgNPs on the chromosomal pattern has also been studied. The importance of this study lies in the possibility of the synthesis of AgNPs using this yeast since most nanoparticle preparation methods utilize molds.

Combination of AgNPs and Domiphen is Antimicrobial Against Biofilms of Common Pathogens.

PurposeThe aim was to evaluate the antimicrobial potential of AgNPs synthesized with Artemisia argyi leaf extract and investigate the antimicrobial synergistic effects of AgNPs combined with domiphen and provide an efficient and broad-spectrum combination drug strategy.MethodsAgNPs synthesized with Artemisia argyi leaf extract were studied using UV–vis spectroscopy, FTIR spectroscopy and particle size analysis. Then, Artemisia argyi leaf extract-synthesized AgNPs and domiphen were tested against Acinetobacter baumannii (ATCC 19606), Staphylococcus aureus (ATCC 6538), Escherichia coli (8099) and Candida albicans (ATCC 10231), respectively. Then, we explore synergistic antimicrobial effect and synergistic anti-biofilm effect through combined drug susceptibility test and combined drug minimum biofilm eradication concentration (MBEC50) test.ResultsCharacteristic absorption bands of AgNPs were found near 430 nm in the UV–vis spectrum. Particle size analysis results revealed that the average particle size of Artemisia argyi leaf extract-synthesized AgNPs was 77.6 nm. Artemisia argyi leaf extract-synthesized AgNPs showed high antimicrobial activity against the above four strains. Minimum inhibitory concentration (MIC) of Artemisia argyi leaf extract-synthesized AgNPs against strains was 1 μg/mL for Acinetobacter baumannii, 2 μg/mL for Staphylococcus aureus, Escherichia coli and Candida albicans. MBEC50 of Artemisia argyi leaf extract-synthesized AgNPs against strains was 2 μg/mL for Acinetobacter baumannii, 4 μg/mL for Staphylococcus aureus, 1/2 μg/mL for Escherichia coli and 2 μg/mL for Candida albicans. The combination of Artemisia argyi leaf extract-synthesized AgNPs and domiphen has synergistic antimicrobial effect and synergistic anti-biofilm effect. Fractional inhibitory concentration (FIC) was ≤0.5.ConclusionArtemisia argyi leaf extract-synthesized AgNPs had antimicrobial activity against the above four strains. The combination of Artemisia argyi leaf extract-synthesized AgNPs and domiphen has synergistic antimicrobial effects to reduce the dosage of each antimicrobial drugs. Artemisia argyi leaf extract-synthesized AgNPs and domiphen have synergistic anti-biofilm effects.

Radio-sensitivity on MCF-7 cells of silver nanoparticles synthesized by Silybum marianum

In the green synthesis method, various plants gain importance due to the synergistic effect created by their rich phytochemical properties. In this study, SM (thistle-Silybum marianum) plant, which is known with its antioxidant and anticarcinogenic properties in the literature, forms the source of motivation. Silver nanoparticles (Ag NPs) were synthesized in SM aqueous extracts by this method. The formation of Ag NPs was confirmed by transmission electron microscopy (TEM), UV-Vis and XRD spectrophotometers. Cytotoxicity of MCF-7 cells, incubated for 24 and 48 hours with different mass concentrations of Ag NPs, was determined by MTT test. Additionally, in this study, the radio-sensitizing effects of Ag NPs synthesized via SM seeds were investigated for the first time. Moreover, MCF-7 cells incubated with Ag NPs for 1-2 and 4 hours were exposed to 6 MV energy X-ray radiation.

Silver Nanoparticles Genotoxicity on Normal Human Melanocyte Cell Line (HBF-4 cells).

Nanotechnology has been rapidly used in diverse consumer products in both medical and industrial fields; which has raised various concerns. Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials due to their excellent broad-spectrum antibacterial properties. However the studies on their cyto- and geno-toxic effects are scarce. The present study aim to evaluate the DNA damaging effects of AgNPs and estimate the release of intracellular reactive oxygen species (ROS) on HBF-4 normal human melanocyte cells. The study was conducted on HBF-4 cells, they will be treated with AgNPs at different levels (0.01 ,0.1,1, 10 and 100 μg/mL), LC50 was determined using MTT viability assay. Cells were then divided into two groups: the first was treated with the LC50 dose and the second was treated with 0.1 LC50 dose. DNA fragmentation assay using diphenylamine (DPA) technique and Intracellular ROS assay were measured and compared to control group. Significant increases in DNA damage and release of intracellular ROS were observed on treated HBF-4 cells with LC50 and its 1/10 LC50 value in comparison to the control group. Conclusion: silver nanoparticles can induce oxidative stress and DNA damage in normal human melanocyte cells with a potential carcinogenic effect to be considered. Further investigations form their genetic alterations mechanisms are required.

Effect of Silver Nanoparticles and L-Carnitine Supplement on Mixed Vaginitis Caused by Candida albicans/ Staphylococcus aureus in Mouse Models: An Experimental Study.

The evolution of antimicrobial-resistant pathogens is a global health and development threat. Nanomedicine is rapidly becoming the main driving force behind ongoing changes in antimicrobial studies. Among nanoparticles, silver (AgNPs) have attracted attention due to their versatile properties. The study aimed to investigate the effects of AgNPs and L-carnitine (LC) on mixed Candida albicans and Staphylococcus aureus in the mice vaginitis model. Study of antimicrobial activity of AgNPs evaluated by Minimum Inhibitory Concentration (MIC) and Minimum Biocidal Concentration (MBC) assays. AgNPs inhibited biofilm formation of microbial strains, which was tested by using crystal violet staining. In the current study, we evaluated the effects of AgNPs and LC in NMRI mice infected intravaginally with C. albicans/ S. aureus for two weeks. The proportion of mice in each stage of the estrous cycle (proestrus, estrus, metestrus, and diestrus) was examined. Histological properties were assessed by hematoxylin/ eosin (H&E) staining of formalin-fixed, paraffin-embedded vaginal tissue sections. Based on the results, MICs of AgNPs against S. aureus, C. albicans, and their combination were 252.3, 124.8, and 501.8ppm, and their minimum biofilm inhibitory concentration (MBIC) was 500, 250, and 1000ppm, respectively. The estrous cycle in the treated group was similar to the control. Vaginal histology and cytology showed that LC can improve tissue damages caused by vaginitis and AgNPs. This study demonstrates the promising use of AgNPs as antimicrobial agents and the combination of AgNPs/ LC could be a great future alternative in the control of vaginitis.

Toxicity and action mechanisms of silver nanoparticles against the mycotoxin-producing fungus Fusarium graminearum

IntroductionFusarium graminearum is a most destructive fungal pathogen that causes Fusarium head blight (FHB) disease in cereal crops, resulting in severe yield loss and mycotoxin contamination in food and feed. Silver nanoparticles (AgNPs) are extensively applied in multiple fields due to their strong antimicrobial activity and are considered alternatives to fungicides. However, the antifungal mechanisms and the effects of AgNPs on mycotoxin production have not been well characterized. ObjectivesThis study aimed to investigate the antifungal activity and mechanisms of AgNPs against both fungicide-resistant and fungicide-sensitive F. graminearum strains, determine their effects on mycotoxin deoxynivalenol (DON) production, and evaluate the potential of AgNPs for FHB management in the field. MethodsScanning electron microscopy (SEM), transmission electron microscopy (TEM), and fluorescence microscopy were used to examine the fungal morphological changes caused by AgNPs. In addition, RNA-Seq, qRT-PCR, and western blotting were conducted to detect gene transcription and DON levels. ResultsAgNPs with a diameter of 2 nm exhibited effective antifungal activity against both fungicide-sensitive and fungicide-resistant strains of F. graminearum. Further studies showed that AgNP application could impair the development, cell structure, cellular energy utilization, and metabolism pathways of this fungus. RNA-Seq analysis and sensitivity determination revealed that AgNP treatment significantly induced the expression of azole-related ATP-binding cassette (ABC) transporters without compromising the control efficacy of azoles in F. graminearum. AgNP treatment stimulated the generation of reactive oxygen species (ROS), subsequently induced transcription of DON biosynthesis genes, toxisome formation, and mycotoxin production. ConclusionThis study revealed the underlying mechanisms of AgNPs against F. graminearum, determined their effects on DON production, and evaluated the potential of AgNPs for controlling fungicide-resistant F. graminearum strains. Together, our findings suggest that combinations of AgNPs with DON-reducing fungicides could be used for the management of FHB in the future.

Bioengineered phytomolecules-capped silver nanoparticles using Carissa carandas leaf extract to embed on to urinary catheter to combat UTI pathogens.

Rising incidents of urinary tract infections (UTIs) among catheterized patients is a noteworthy problem in clinic due to their colonization of uropathogens on abiotic surfaces. Herein, we have examined the surface modification of urinary catheter by embedding with eco-friendly synthesized phytomolecules-capped silver nanoparticles (AgNPs) to prevent the invasion and colonization of uropathogens. The preliminary confirmation of AgNPs production in the reaction mixture was witnessed by the colour change and surface resonance plasmon (SRP) band at 410nm by UV-visible spectroscopy. The morphology, size, crystalline nature, and elemental composition of attained AgNPs were further confirmed by the transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD) technique, Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The functional groups of AgNPs with stabilization/capped phytochemicals were detected by Fourier-transform infrared spectroscopy (FTIR). Further, antibiofilm activity of synthesized AgNPs against biofilm producers such as Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were determined by viability assays and micrographically. AgNPs coated and coating-free catheters performed to treat with bacterial pathogen to analyze the mat formation and disruption of biofilm formation. Synergistic effect of AgNPs with antibiotic reveals that it can enhance the activity of antibiotics, AgNPs coated catheter revealed that, it has potential antimicrobial activity and antibiofilm activity. In summary, C. carandas leaf extract mediated synthesized AgNPs will open a new avenue and a promising template to embed on urinary catheter to control clinical pathogens.

Green synthesis of Ag nanoparticles in oil-in-water nano-emulsion and evaluation of their antibacterial and cytotoxic properties as well as molecular docking

Increasing use of silver nanoparticles (AgNPs) in various fields as mentioned recently like cosmetology, clinical nanotechnologies and medicine causes the growth of a nontoxic and green synthesis methodology. The present study provided a facile stable one-step synthesis of AgNPs in the presence of Artemisia herba-alba, Mentha, Rosmarinus and Ranunculus aqueous oil extract as reductant and stabilizer via oil-in-water nano-emulsion. Due to experimental results, in the presence of Artemisia herba-alba extract, AgNPs indicated smaller size, uniform shape and well dispersed NPs. Synthesized nanostructures characterized by using various techniques like XRD, UV–Vis, FT-IR, TEM, SEM, nano sizer and zeta potential measurements. The effect of some reaction parameters (the molar ratio of AgNO 3 , extract volume, pH and temperature) on the AgNPs investigated as well. Additionally, strong antibacterial effects of AgNPs found against four gram-negative and three gram-positive bacteria due to cell death according to increasing membrane permeability and bacterial wall integrity disruption. WST-1 exposed cytotoxicity potent index on the cancerous cell lines as established by the low IC50 value of 1 ppm. Binding energy of Ag metal with bacteria calculated by molecular docking and indicated that all bacteria have good interaction with silver NPs and confirmed antibacterial manner of Ag. Therefore, Produced AgNPs can be introduced as an effective antibacterial agent as well as a potent index of cytotoxicity effect on cancerous cell lines that leads to effective usage in nono-drug design and formulations in near future.

Spectral and structure characterization of Ferula assafoetida fabricated silver nanoparticles and evaluation of its cytotoxic, and photocatalytic competence

This study aims to develop an eco-friendly method for rapidly synthesizing silver nanoparticles (AgNPs) using Asafoetida ethanol extracts and to validate AgNPs synthesis using UV–vis spectroscopy (absorption spectrum), FTIR (functional groups), XRD (crystallinity), FE-SEM (size of the particles) and SEM-EDAX (Purity). Furthermore, to evaluate the anti-proliferative effect of Ag NPs against grown cultured L6 cell lines, studies have shown that AgNPs biosynthesis inhibits cancer cell growth compared to control cell lines. UV–vis absorption verified the existence of Ag NPs, and the spectrum was observed at 480 nm. Functional groups are present in the synthesized Ag NPs were shifted on 528.48 cm−1 confirmed using an FT-IR spectrum. Consequently, anti-cancer efficacy observed the IC50 value of As Ag NPs against L6 cells was 1.0 μg/mL for 48 h. Finally, using a halogen lamp, studies explored the photocatalytic degradation of AgNPs against the methylene blue radioactive dye and achieved a 96 percent degradation rate in 90 min. Asafoetida mediated silver nanoparticles show grater photodegradation for methylene blue dye, which is present in textile industries, when exposed to solar light, and it has a wide range of potential applications in wastewater treatment. As a whole, biosynthesized silver nanoparticles showed excellent cytotoxic, antioxidant, and photocatalytic dye degradation effects.

Silver Nanoparticles Modulate the Epithelial-to-Mesenchymal Transition in Estrogen-Dependent Breast Cancer Cells In Vitro.

Silver nanoparticles (AgNPs) are frequently detected in many convenience goods, such as cosmetics, that are applied directly to the skin. AgNPs accumulated in cells can modulate a wide range of molecular pathways, causing direct changes in cells. The aim of this study is to assess the capability of AgNPs to modulate the metastasis of breast cancer cells through the induction of epithelial-to-mesenchymal transition (EMT). The effect of the AgNPs on MCF-7 cells was investigated via the sulforhodamine B method, the wound healing test, generation of reactive oxygen species (ROS), the standard cytofluorimetric method of measuring the cell cycle, and the expression of EMT marker proteins and the MTA3 protein via Western blot. To fulfill the results, calcium flux and HDAC activity were measured. Additionally, mitochondrial membrane potential was measured to assess the direct impact of AgNPs on mitochondria. The results indicated that the MCF-7 cells are resistant to the cytotoxic effect of AgNPs and have higher mobility than the control cells. Treatment with AgNPs induced a generation of ROS; however, it did not affect the cell cycle but modulated the expression of EMT marker proteins and the MTA3 protein. Mitochondrial membrane potential and calcium flux were not altered; however, the AgNPs did modulate the total HDAC activity. The presented data support our hypothesis that AgNPs modulate the metastasis of MCF-7 cells through the EMT pathway. These results suggest that AgNPs, by inducing reactive oxygen species generation, alter the metabolism of breast cancer cells and trigger several pathways related to metastasis.

Assessment of behavioral changes and antitumor effects of silver nanoparticles synthesized using diosgenin in mice model

Silver nanoparticles (AgNPs) are widely accepted for their physical, chemical and biological properties which could relate to their applications in medicine. Hence, these particles of the nano-regime could be a potential contender in search for novel medication with psychotherapeutic and antitumor potential. Considering this background, the objective of the present study was set to comparatively assess the anxiolytic, antidepressant and antitumor effects of AgNPs synthesized using diosgenin, a plant derived saponin of Dioscorea oppositifolia. The synthesized nanoparticles were characterized by using UV–Vis, FTIR, TEM, SEM, DLS and XRD. The AgNPs after characterization were tested at varying doses for their anxiolytic and antidepressant effects in Swiss albino mice. The mice spent more time in the open arm after treatment in elevated plus maze test (EPM). Significant dose dependent reduction in immobility time was observed in forced induced swimming test (FST). Dalton's ascites lymphoma (DAL) was induced in vivo for analysing the antitumor effect of AgNPs. After treatment with AgNPs, a significant reduction was observed in the body weight of the tumor-induced mice. Analysis of hematological parameters, lipid peroxidation marker, liver and kidney function tests indicate the oncosuppressive effects of the AgNPs. This was evidently observed via the effective revival of all these parameters to near-normal after treatment with AgNPs at a dose of 10 mg/kg. To conclude, the findings of the present study indicate that AgNPs synthesized using diosgenin could be considered as a valuable candidate for use in and as anxiolytic, antidepressant and antitumor medications.

AgNPs reduce reproductive capability of female mouse for their toxic effects on mouse early embryo development.

Silver nanoparticles (AgNPs) are widely applied in the field of personal protection for their powerful toxic effects on cells, and recently, a new type of vaginal gel with AgNPs is used to protect the female reproductive tract from microbes and viruses. However, a high risk of AgNPs to the fetus and the underlying mechanism of AgNPs to interfere in embryo development still remain unclear. Thus, this study investigated the impact of two drugs of vaginal gel with AgNPs on reproductive capability of the female mouse by animal experiment. Then, kinetics of AgNPs affecting embryo development was investigated by in vitro embryos culturing, and cell membrane potential (CMP) of zygotes was analyzed by DiBAC4(3) staining. Results indicated that one of the drugs of vaginal gel certainly injured embryo development in spite of no apparent histological change found in ovaries and uteruses of drug-treated mice. In vitro embryo culturing discovered that the toxic effect of AgNPs on embryo development presented particle sizes and dose dependent, and AgNP treatment could rapidly trigger depolarization of the cell membrane of zygotes. Moreover, AgNPs changed the gene expression pattern of Oct-4 and Cdx2 in blastocysts. All these findings suggest that AgNPs can interfere with normal cellular status including cell membrane potential, which has not been noticed in previous studies on the impact of AgNPs on mammalian embryos. Thus, findings of this study alarm us the risk of applying vaginal gel with AgNPs in individual caring and protection of the female reproductive system.

Efficacy of green synthesized silver nanoparticles via ginger rhizome extract against Leishmania major in vitro.

IntroductionLeishmaniasis is a major public health problem that causes by parasite of the genus Leishmania. The pentavalent antimonial compounds that used for treatment are not safe or effective enough. The aim of the present study was preparation and evaluation of the efficacy of green synthesized silver nanoparticles against Leishmania major (L. major) in vitro.MethodsTo synthesis silver (Ag) nanoparticles (NPs), ginger extract was added to the 0.2mM AgNO3 aqueous solution (1:20). Effects of different concentrations of Ag-NPs on the number of L. major promastigotes were investigated using counting assay. The MTT test was applied to determine the toxicity of Ag-NPs on promastigotes of L. major, as well as, macrophage cells. Then, to evaluate the anti-amastigotes effects of Ag-NPs, parasites within the macrophages were counted by light microscope. Furthermore, to determine the induced apoptosis and necrotic effects of Ag-NPs on promastigotes, flow cytometry method was employed using annexin staining.ResultsThe effect of Ag-NPs on promastigotes and amastigotes of L. major was effective and has a reverse relationship with its concentration. According to the results of anti-amastigote assay, the IC50 value of this nanoparticle was estimated 2.35 ppm after 72h. Also, Ag-NPs caused Programmed Cell Death (PCD) in promastigotes of L. major and showed 60.18% of apoptosis.DiscussionBased on the mentioned results, it can be concluded that Ag NPs has a beneficial effect on promastigote and amastigote forms of L. major in vitro. Hence, these nanoparticles could be applied as promising antileishmanial agents for treatment of Leishmania infections.

Study the Synergistic Effect of AgNPs with Antibiotics on Klebsiella Pneumoniae Isolates Which Diagnosed by Molecular Methods

The current study was conducted to study the synergistic effect of AgNPs with anti-biotics on Klebsiellapneumonia isolates, where 50 samples were collected from different pathological conditions (wounds - burns- urine - ear - and excretion) on the Maconkey Agar . To the Klebsiella , it was diagnosed microscopicallyand biochemically and was also diagnosed by the Vitek2 device, whose results were identical with thebiochemical diagnosis, and the isolates were also subjected to molecular diagnosis for confirmation byusing the PCR technique based on the diagnostic gene 16SrRNA, which is characterized by being good,stable and low heterogeneity for a long time in the bacterial type Ten types of antibiotics were selectedand immersed in silver nanoparticles At a concentration of 20Mm, a test was conducted for the synergybetween the silver nanoparticles AgNPs and the antagonists towards 12 isolates of Klebsiella bacteria, asthey were applied to Muller-Hunton medium and after they dried up, the anti-saturated tablets were fixedwith a silver particle solution, and after the expiration of the incubation period, the diameter of the inhibitionarea around the tablets was measured in mm According to the standard results, the results of the statisticalanalysis showed that the interaction of silver nanoparticles with the antibiotics had a significant effect onincreasing the sensitivity of the isolates towards the synergistic antagonists, as the general rate of inhibitiondiameters of the antagonists (Impenem, Gentamicin, Amikacin Ciprofloxacillin) was (32.59, 21.6, 18.98,36.18), respectively. , This activity is due to the ability of the nanoparticles to bind to the surface of thebacterial cell The binding causes structural damage and changes such as permeability, which facilitates theentry of the antagonist into the cell and thus its death. As for the synergies with the antagonists Tetracycline,Vancomycin, Erythromycin did not show efficacy in the direction of Klebsiella isolates did not give goodresults of synergy as it has a weak effect towards negative bacteria and it is as a non-synergistic antagonistbecause it does not It has effective binding sites for silver nanoparticles.

Global gene expression signatures in response to citrate-coated silver nanoparticles exposure

Silver nanoparticles (AgNPs) are widely used in medical and commercial products for their unique antibacterial functions. However, the impact of AgNPs on human neural development is not well understood. To investigate the effect of AgNPs on human neural development, various doses of 20 nm citrate-coated AgNP (AgSC) were administered to human embryonic stem cell derived neural progenitors during the neuronal differentiation. Immunofluorescence staining with neuronal progenitor markers SOX2 (sex determining region Y-box 2) and Nestin (VI intermediate filament protein) showed that AgSC inhibited rosette formation, neuronal progenitor proliferation, and neurite outgrowth. Furthermore, AgSC promoted astrocyte activation and neuronal apoptosis. These adverse effects can be partially recovered with ascorbic acid. A genome-wide transcriptome analysis of both AgSC treated and untreated samples indicated that the most up-graduated genes were a group of Metallothionein (1F, 1E, 2A) proteins, a metal-binding protein that plays an essential role in metal homeostasis, heavy metal detoxification, and cellular anti-oxidative defence. The most significantly down-regulated genes were neuronal differentiation 6 (NEUROD6) and fork head box G1 (FOXG1). GO analyse indicated that the regulation of cholesterol biosynthetic process, neuron differentiation, synapse organization and pattern specification, oliogenesis, and neuronal apoptosis were the most impacted biological processes. KEGG pathway analyse showed that the most significantly impacted pathways were C5 isoprenoid, axon guidance, Notch, WNT, RAS-MAPK signalling pathways, lysosome, and apoptosis. Our data suggests that AgSCs interfered with metal homeostasis and cholesterol biosynthesis which induced oxidative stress, inhibited neurogenesis, axon guidance, and promoted apoptosis. Supplementation with ascorbic acid could act as an antioxidant to prevent AgSC-mediated neurotoxicity.

Silver nanoparticle-protein interactions and the role of lysozyme as an antagonistic antibacterial agent

The photoreductive synthesis and antibacterial activity of silver nanoparticles (AgNP) prepared in the presence of bovine serum albumin (BSA) and lysozyme (LZ) were evaluated. AgNP@BSA showed similar antibacterial activity to those stabilized with citrate (AgNP@CIT) and to an AgNO3 solution, suggesting the releases of Ag+ as the mechanism of death. In contrast, AgNP@LZ solutions showed no activity, although LZ behaves as a moderately antibacterial peptide. Furthermore, the addition of LZ to the AgNP@CIT or AgNP@BSA solutions induced their agglomeration and suppressed their original antibacterial efficacy. This antagonistic antibacterial effect exerted by LZ on AgNPs is associated with electrostatic interactions exerted by LZ. Specific metal-LZ interactions produce a harder protein corona on AgNP@LZ that retains Ag+, while LZ acts as a glue for AgNP@CIT or AgNP@LZ due to its opposite electrical charge, besides strong binding to Ag+avoiding the bactericide effect. Therefore, bactericidal effects of AgNP in biological media may be modulated by specific protein interactions.

Pollution- induced community tolerance framework - disc diffusion method to assess the impact of silver nanoparticles in soils: Potential relevance for risk assessment

The toxicity of silver nanoparticles (AgNPs) in soil bacterial communities (SBC) has been widely reported. However, the bacterial related endpoints have not been effectively considered in the environmental risk assessment (ERA) for nanomaterials. Thus, we aimed to study the long-term effects of AgNPs, or AgNO3 (counterpart), [5 μg (Ag) kg−1] on SBC: (1) at structural level (using denaturing gradient gel electrophoresis-DGGE) and, (2) in terms of bacterial induced tolerance (which is the foundation of the pollution-induced community tolerance - PICT) using a disc diffusion assay (0.1 μg, 1 μg or 10 μg of each silver form). After day-56 of exposure, the structure of SBC was affected by AgNPs and AgNO3, though still sharing 71.9% similarity with the non-exposed SBC. Also, the SBC homogeneity significantly decreased after exposure to silver, suggesting a possible tolerance effect. Regarding tolerance assays, AgNO3 was more effective in inhibiting the SBC growth than AgNPs, and both in a dose-dependent manner (10 μg > 1 μg > 0.1 μg). A second exposure revealed a decrease in tolerance of SBC to AgNO3. Also, a lower amount of AgNO3 is needed to change SBC tolerance. PICT analysis revealed that previous exposure to AgNPs did not increase tolerance-effect in SBC. Overall, AgNPs changes the SBC structure and tolerance, but does not increase the tolerance on a second exposure. Thus, this study highlights the usefulness of combined bacterial endpoints (DGGE, and PICT-disc diffusion tests) for potential inclusion in the ERA of AgNPs in soil ecosystems.

Biochemical Modulatory and Protective Effects of the Hydroalcoholic Extract of Scrophularia striata on the Hepatotoxicity of Silver Nanoparticles in the Rat Model

BACKGROUND: Silver nanoparticles (AgNPs) are widely used in various products. On the other hand, they can cause a variety of toxicity in living organisms, such as biochemical changes and oxidative stress in the liver. Scroph-ularia striata plant can affect the toxicity of AgNPs in diverse parts of the body due to the potent antioxidant compounds. OBJECTIVES: The present study aimed to investigate the modulatory impact of the hydroalcoholic extract of Scrophularia striata on the hepatotoxicity and oxidative stress caused by AgNPs in male Wistar rats. The measured hepatic enzymes and serum biochemical metabolites included alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, gamma-glutamyl transferase, albumin, Globulin, total protein, blood urea nitrogen, creatinine, total bilirubin, and direct bilirubin. In addition, the assessed blood oxidative stress markers entailed malondialdehyde, total antioxidant capacity, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx). METHODS: A total of 30 male rats with an average weight of 200±20 g were randomly assigned to five experi-mental groups of six. Animals in group 1 as the negative control received 2 ml distilled water and in group 2 as positive control received 200 ppm AgNPs (i.e., hepatotoxic dose). The rats in groups 3, 4, and 5 received 20, 60, and 180 mg/kg Scrophularia striata extract and 200 ppm AgNPs in 30 days, respectively. The animals were sacri-ficed under slight anesthesia 24 h after the last treatment. RESULTS: Hepatic enzymes, serum biochemical metabolites, and oxidative stress markers, mainly CAT, SOD, and GPx in groups 4 and 5 were significantly different from the positive and negative control groups (p <0.05). CONCLUSIONS: Scrophularia striata plant owing to the presence of some special ingredients, such as flavonoids can compensate for the side effects of AgNPs in the body.

Neurotoxicity of silver nanoparticles in the animal brain: a systematic review and meta-analysis.

About 30% of all nanoparticle products contain silver nanoparticles (AgNPs). With the increasing use of AgNPs in industry and medicine, concerns about the adverse effects on the environment, and the possible toxicity of these particles to primary cells and towards organs such as the brain and nervous system increased. In this paper, the toxicity of AgNPs in neurons and brain of animal models was investigated by a systematic review and meta-analysis. The full texts of 26 relevant studies were reviewed and analyzed. Data from nine separate experiments in five articles were analyzed by calculating the standardized mean differences between viability of treated animals and untreated groups. Subgroup analysis was conducted. In addition, asystematic reviewprovided a complete, exhaustive summary of all articles. The results of the meta-analysis showed that AgNPs are able to cause neuronal death after entering the brain (standardized mean difference (SMD) = 2.87; 95% confidence interval (CI) 2.1-3.61; p < 0.001). AgNPs sized smaller or larger than 10nm could both cause neuronal cell death. This effect could be observed for a long time (up to 6months). Neurons from embryonic animals whose mothers had been exposed to AgNPs during pregnancy were affected as much as animals that were themselves exposed to AgNPs. Toxic effects of AgNPs on memory and cognitive function were also observed. Studies have shown that inflammation and increased oxidative stress followed by apoptosis are likely to be the main mechanisms of AgNPs toxicity. AgNPs can enter the brain with a long half-life and it can cause neuronal death after entering the brain. AgNPs can manifest proinflammatory cascades in the CNS and BBB. Some toxic effects were detected in the cerebral cortex, hypothalamus, hippocampus and others. Studies have shown that inflammation and increased oxidative stress lead to apoptosis, the main mechanism of AgNPs neurotoxicity, which can be caused by an increase in silver ions from AgNPs.