Argovit™ Silver Nanoparticles Effects on Allium cepa: Plant Growth Promotion without Cyto Genotoxic Damage (original) (raw)
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Cytotoxic and Genotoxic effects of Silver Nanoparticles on Allium cepa
Several mutagenic agents may be present in substances released in the environment, which may cause serious environmental impacts. Among these substances, there is a special concern regarding the widespread use of silver nanoparticles (AgNP) in several products due to their widely known bactericidal properties, including in the medical field and the food industry (e.g., active packaging). The assessment of the effects of AgNP released in the environment, having different concentrations, sizes, and being associated or not to other types of materials, including polymers, is therefore essential. In this research, the objective was to evaluate the genotoxic and cytotoxic effects of AgNP (size range between 2 and 8 nm) on root meristematic cells of Allium cepa (A. cepa). Tests were carried out in the presence of colloidal solution of AgNP and AgNP mixed with carboxymethylcellulose (CMC), using distinct concentrations of AgNP. As a result, when compared to control samples, AgNP induced a mitotic index decrease and an increase of chromosomal aberration number for two studied concentrations. When AgNP was in the presence of CMC, no cytotoxic potential was verified, but only the genotoxic potential for AgNP dispersion having concentration of 12.4 ppm.
Genotoxicity of silver nanoparticles in Allium cepa
Science of The Total Environment, 2009
Potential health and environmental effects of nanoparticles need to be thoroughly assessed before their widespread commercialization. Though there are few studies on cytotoxicity of nanoparticles on mammalian and human cell lines, there are hardly any reports on genotoxic and cytotoxic behavior of nanoparticles in plant cells. This study aims to investigate cytotoxic and genotoxic impacts of silver nanoparticles using root tip cells of Allium cepa as an indicator organism. A.cepa root tip cells were treated with four different concentrations (25, 20, 75, and 100 ppm) of engineered silver nanoparticles (below 100 nm size) dispersion, to study endpoints like mitotic index, distribution of cells in mitotic phases, different types of chromosomal aberrations, disturbed metaphase, sticky chromosome, cell wall disintegration, and breaks. For each concentration five sets of microscopic observations were carried out. No chromosomal aberration was observed in the control (untreated onion root tips) and the mitotic index (MI) value was 60.3%. With increasing concentration of the nanoparticles decrease in the mitotic index was noticed (60.30% to 27.62%). The different cytological effects including the chromosomal aberrations were studied in detail for the treated cells as well as control. We infer from this study that silver nanoparticles could penetrate plant system and may impair stages of cell division causing chromatin bridge, stickiness, disturbed metaphase, multiple chromosomal breaks and cell disintegration. The findings also suggest that plants as an important component of the ecosystems need to be included when evaluating the overall toxicological impact of the nanoparticles in the environment.
Cytological and Molecular Effects of Silver Nanoparticles (AgNPs) on Vicia faba M1 Plants
Journal of Agricultural Chemistry and Biotechnology
Silver nanoparticles (AgNPs) are among the most widely used nanoparticles and are found in various types of products. In the past few years, these nanoparticles have received significant attention as pesticides for agricultural applications. Utility of AgNPs as efficient pesticides would become a reality if the researches provided some understanding of toxicity of these nanoparticles. Evaluation of the potential genotoxic effects of AgNPs on Vicia faba M 1 plants was the main goal in this study. Seeds of V. faba (Sakha 1 variety) were treated with three concentrations of AgNPs (25, 50 and 75 ppm) and M 1 populations raised from these seeds were investigated at different levels. Results indicated that all the three concentrations were able to induce significant increase in seed germination percentage (G) and germination rate index (GRI) in addition to root length and seedling vigor index (SVI) compared to control, while no significant differences were detected among the three AgNPs concentrations and control for shoot length. The maximum germination percentage (99.00 %) was found at the 50 ppm concentration while the highest values of root length (15.57 cm) and seedling vigor index (43.77) were recorded at the 25 ppm concentration. Cytological analysis showed that only the concentration of 25 ppm significantly reduced mitotic index (83.47 %) compared to control (91.38 %). Moreover, all treatments caused significantly increase in the percentage of abnormal cells, while the lower concentration (25 ppm) induced the highest percentage of abnormalities (6.90 %) compared to the other treatments. On the molecular level, the effects of AgNPs on genomic template stability (GTS) were measured based on RAPD-PCR analysis using 16 arbitrary primers. All AgNPs concentrations caused reduction in GTS % values; compared to control, which showed decrease in GTS % values as AgNPs concentrations increased. These results indicated that AgNPs had toxic effects on V. faba M 1 plants at cytological and molecular levels.
Journal of Environmental Chemical Engineering, 2019
Green and High throughput production of silver nanoparticles (AgNPs) having controlled size suitable for industrial applications were obtained. Rice starch was used in this study for the production of AgNPs, as it acts as reducing of Ag + to Ag 0 , as well as stabilizing for the obtainable AgNPs. Two concentrations of AgNPs coded as AgNPs-2000 and AgNPs-4000 ppm were successfully prepared. The AgNPs attained were characterized via UV-vis, TEM, EDX, and zeta potential (ζ-potential). The average particle size of AgNPs (2000ppm) was 8nm with PDI=0.01 which affirm the monodispersity and homogeneity of the formed AgNPs while, the average size for the other concentration of AgNPs (4000ppm) was 24nm with PDI=0.021. The as prepared AgNPs of high concentration (4000ppm) together with the commercialized ZnNPs were used for the genotoxicity study. Root-tips was used for cytogenetic studies using onion (Allium cepa L.) which are excellent materials for cytological and genotoxicity studies. Genotoxicity results explored that, by using AgNPs ≥ 40 ppm, the abnormalities disturbed chromosomes were observed and detected, that reflects the genotoxicity effect of these nanoparticles at this dose. In addition, the commercial available ZnNPs with the recommended dose (2 g/L) displayed also severe genotoxicity on A. cepa L. root meristem cells.
In vitro and in vivo genotoxicity of silver nanoparticles
The biocidal effect of silver nanoparticles (Ag-np) has resulted in their incorporation into consumer products. While the population exposed to Ag-np continues to increase with ever new applications, Ag-np remains a controversial research area with regard to their toxicity in biological systems. Here a genotoxic and cytotoxic approach was employed to elucidate the activity of Ag-np in vitro and in vivo. Characterization of Ag-np using scanning electron microscopy revealed a size range of 90-180 nm. Cytotoxic potential of Ag-np was evaluated in human lymphocytes via cell viability assay (Trypan blue dye exclusion method, MTT and WST assay). The uptake and incorporation of Ag-np into the lymphocytes was confirmed by flow cytometry. Additionally apoptosis (AnnexinV-FITC-PI staining) and DNA strand breaks (comet assay) in human lymphocytes revealed that Ag-np at concentration 25 g/ml can cause genotoxicity. In vivo experiments on plants (Allium cepa and Nicotiana tabacum) and animal (Swiss albino male mice) showed impairment of nuclear DNA. Induction of oxidative stress was also studied. The DNA damage and chromosomal aberrations raise the concern about the safety associated with applications of the Ag-np. A single ip administration of Ag-np gave a significant (P ≤ 0.05) increase in the frequency of aberrant cells and Tail DNA percent at concentrations 10 mg/kg body weight and above. Results of comet assay in A. cepa and N. tabacum demonstrated that the genotoxic effect of Ag-np was more pronounced in root than shoot/leaf of the plants. The present study indicated a good correlation between the in vitro and in vivo experiments. Therefore the biological applications employing Ag-np should be given special attention besides adapting the antimicrobial potential. (A. Mukherjee). which cause problems during the toxicological assessment of novel 35 nanomaterials [2]. 36 Many classes of silver nanoparticles (Ag-np) have been syn-37 thesized and widely applied for their bactericidal and viricidal 38 properties [3,4]. Worldwide an extensive growth is projected in 39 the Ag-np market [5] and it is unclear whether the exposure of 40 humans, animals and plants to Ag-np through industrial or domes-41 tic waste could produce harmful biological responses [6]. There are 42 a significant number of studies on the genotoxicity and cytotox-43 icity of silver nanoparticles on mammalian and human cell lines 44 [7-18] and a few reports on plant systems [19,20]. Majority of nan-45 otoxicity research has focused on cell culture systems and to assess 46 nanotoxicity accurately. Fischer and Chan [21] in their review arti-47 cle mentioned the need for in vivo studies. Therefore, we examined 48 the genotoxic potential of Ag-np in both in vitro (in human lympho-49 cyte) and in vivo (mouse bone marrow cells, Allium and Nicotiana) 50 systems. Apart from animal system, plants are an important 51 component of the ecosystem that needs to be included when eval-52 uating the overall toxicological impact of the nanoparticles in the 53 1383-5718/$ -see front matter G Model MUTGEN 402222 1-10 2 M. Ghosh et al. / Mutation Research xxx (2012) xxx-xxx environment. The plants selected for the study (Allium cepa and 54 Nicotiana tabacum) are efficient test systems for screening chem-55 icals and in situ monitoring for genotoxicity of environmental 56 contaminants [22-26]. They have been used successfully in our 57 laboratory as a biomarker of genotoxicity of nanomaterials [27,28]. 58 Ag-np (≤100 nm) was purchased and characterized using trans-59 mission electron microscopy (TEM), scanning electron microscope 60 (SEM) and X-ray diffraction (XRD), diffraction light scattering (DLS) 61 and UV visible spectrophotometry for size and dispersion. Prior to 62 its genotoxicity evaluation, the nanoparticle was dispersed in solu-63 tion by sonication. For in vitro study, human lymphocytes were used 64 for cytotoxicity (trypan blue dye exclusion, MTT and WST assays) 65 and genotoxicity (comet assay) studies. In addition, flow cytometry 66 was performed to measure the mode of cell death and uptake of Ag-67 np in human lymphocytes. TEM was performed to study structural 68 modifications and uptake of Ag-np in cells. The in vitro results were 69 further substantiated by in vivo studies. Bone marrow cells of mice 70 and root or leaf tissues of Allium and Nicotiana plants were used in 71 the comet assay. 72 The study provides evidence of genotoxicity of Ag-np in plant 73 and mammalian systems and the results demonstrate that there is 74 good correlation between the in vitro and in vivo effects of Ag-np. 75 2. Materials and methods 76 2.1. Ag-np preparation 77 Ag-np was obtained from Sigma-Aldrich, St. Louis, MO, USA. The physical char-78 acteristics of the particles according to the manufacturers data are; size (≤100 nm), 79 purity (99.5%), trace metal basis, surface area (5.0 m 2 /g), density (10.49 g/cc). Ag-80 nps were suspended in PBS or water and dispersed by ultrasonic vibrations (100 W, 81 30 kHz) for 30 min. Ag-np were serially diluted at different concentrations according 82 to the test performed. 83 2.2. Characterization of Ag-np 84 Ag-np powder was characterized using transmission electron microscopy (Jeol 85 JEM-2100 LaB6, 200 kV), scanning electron microscopy, energy-dispersive X-ray 86 spectroscopy (EDX) (Hitachi S-415A Electron Microscope, Tokyo, Japan at 25 kV) 87 and by X-ray diffraction (XRD) analysis. The spectra were recorded in a PW. 3040/60 88 PANalytical X-ray diffractometer Almelo, Netherlands (Cu K␣ radiation, 1.54443) 89 running at 45 kV and 30 mA. The diffracted intensities were recorded from 2 • to 99 • 90 2Â angles. Zeta potential of Ag-np in solution was measured by laser diffractometry 91 using a Nano Size Particle Analyzer (Zen 1600 Malvern, USA). Absorption maxima 92 of Ag-np in solution were scanned by UV-Vis spectrophotometer (Beckman Coulter 93 DU 700, California, USA) for agglomeration at the wavelength of 200-800 nm. 94 2.3. In vitro cytotoxicity and genotoxicity of Ag-np 95 2.3.1. Cell preparation and materials 96 Human blood was obtained from 3 healthy male volunteers between 20 and 97 30 years of age (non smokers and not under any medications), after their con-98 sent. The lymphocytes were obtained by centrifuging blood overlaid on Histopaque 99 (Sigma-Aldrich, St. Louis, MO, USA) according to the method of Boyum [29]. Cell 100 viability was checked by Trypan blue exclusion method [30] and was found to be 101 approximately 95%. All experiments were approved by the Research Ethics Com-102 concentrations of Ag-np (0, 25, 50, 100, 150 and 200 g/ml). Positive control was 105 maintained with methyl methanesulphonate (MMS, 100 M).
The Pharma Innovation Journal, 2018
Background: The silver nanoparticles (AgNPs) are known for their antimicrobial activity against several pathogens. The AgNPs might entered into the environment that could adversely affect the herbs and plants. Purpose: The purpose of the undertaken study was to synthesize AgNPs from Vitex negundo leaf extract and evaluate their effects on different growth parameters of Cassia occidentalis. Methods: The AgNPs were synthesized by treating silver nitrate solution with aqueous solution of Vitex nigundo leaves extract. AgNPs were characterized by the analysis of UV-Visible absorptions spectra. The phytotoxic effects of these synthesized AgNPs on seed germination, shoot and root lengths, fresh weight and dry weight of seedlings and leaf surface area of Cassia occidentalis was evaluated in presterilized petri dishes exposed to different concentration of AgNPs. Results: The AgNPs from Vitex nigundo leaves extract were successfully synthesized and characterized. The results indicated that ex...
Inspite of very wide application of different types of nanoparticles in different commercial fields including pharmaceutical and food industries, the toxic effects of these nanoparticles on living systems have not been clearly established. Increased applications of nanoparticles by human beings lead to accumulation of more and more nanoparticles in the environment which ultimately affect the ecosystem. The current study focused on phytotoxicity of silver nanoparticles to V.radiata and B.campestris crop plants. Effect on seedling growth by nanoparticles is comparatively more than ions solution during treatment period. The test plants exposed to nanoparticle shows that the average particle size was about 25.3 nm which was determined by X-Ray Diffractions spectrophotometer. In addition, result from Fourier Transform Infrared spectrometer reported no change in chemical composition on the basis of vibrations of functional group of molecules in treated root samples. However, Scanning Electron Microscope images revealed depositions of isolated small and spherical nanoparticles in root cells. The nanoparticles appeared to be either filling the epidermal crypt or adhering onto the root surface of test plants.
Background: The industrial production of silver nanoparticles (AgNPs) and its commercial applications are being considerably increased in recent times, resulting in the release of AgNPs in the environment and enhanced probability of contaminations and their adverse effects on living systems. Based on this, the present study was conducted to evaluate the in vitro cytotoxicity of actinomycete-synthesized AgNPs on Allium cepa (A. cepa) root tip cells. A green synthesis method was employed for biosynthesis of AgNPs from Streptomyces sp. NS-33. However, morphological, physiological, biochemical, and molecular analysis were carried out to characterize the strain NS-33. Later, the synthesized AgNPs were characterized and antibacterial activity was also carried out against pathogenic bacteria. Finally, cytotoxic activity was evaluated on A. cepa root tip cells.
In vitro biosynthesis and genotoxicity bioassay of silver nanoparticles using plants
Toxicology in Vitro, 2011
Silver nanoparticles (AgNP-P) from AgNO 3 were synthesized by using the broth prepared from the aromatic spath of male inflorescence of screw pine, Pandanus odorifer (Forssk.) Kuntze AgNP-P was then characterized by UV-visible spectroscopy, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). Functional groups in the broth were analyzed by Fourier Transform infrared spectroscopy (FTIR). Genotoxicity of AgNP-P was assessed by utilizing our well-established Allium cepa assay system with biomarkers including the generation reactive oxygen species (ROS: O ÁÀ 2 and H 2 O 2 ), cell death, mitotic index, micronucleus, mitotic aberrations; and DNA damage by Comet assay. Other chemical forms of silver such as Ag + ion, colloidal AgCl, and AgNP-S at doses 0-80 mg L À1 were included for comparison with AgNP-P. The results revealed that AgNP-P and AgNP-S exhibited similar biological effects in causing lesser extent of cytotoxicity and greater extent of genotoxicity than that was exhibited by Ag + ion alone. Among different tested chemical forms of silver, colloidal AgCl was identified to be the least cytotoxic and genotoxic. Cell death and DNA-damage induced by AgNP-P were prevented by Tiron and dimethyl thiourea that scavenge O ÁÀ 2 and H 2 O 2 , respectively. The present findings demonstrated the role of ROS in the AgNP-induced cell death and DNA damage.