In present study, silver nanoparticles (AgNPs) were produced by employing a "green" biosynthetic method using leaf extract of Cymbopogon citratus (CCLE). The reaction between CCLE and silver nitrate produced black coloured solution inferred as the visual confirmation of nanoparticle synthesis. The UV-visible spectrum of spherical oval shaped CCLE-AgNPs reported absorbance at 420 nm with FCC crystalline lattice confirmed by XRD. The average size of CCLE-AgNPs was reported as 30.6 nm (XRD) and 13.1-30.9 nm (TEM) along with the elemental composition by EDX evaluated to be 10.79 %. The presence of numerous organic metabolites was confirmed by FTIR and validated by GC-MS inferring diverse types of organic metabolites as capping and reducing mediators. The bioactivities reported were: antibacterial (MIC and MBC ranged from 15 to 35 mu g/ml against both Gram + and - cells); anti-biofilm (70-82 %); antidiabetic (76-83 %); and anti-inflammation (60-65 %). The dye degradative kinetics of CCLE-AgNPs against dyes Rhodamine B and Methyl orange followed pseudo-first order reaction rate with % efficiency of 93 % and 95 %, respectively. Thus, our results explicated a quick, environmentally inert, economical method for CCLE-AgNPs amalgamation for viable applications as prospective nanomedicines and nanocatalysts.

The interaction of drugs with DNA is crucial for understanding their mechanism of action, particularly in the context of gene expression regulation. Erdafitinib (EDB), a pan-FGFR (fibroblast growth factor receptor) inhibitor approved by the FDA, is a potent anticancer agent used primarily in the treatment of urothelial carcinoma. In this study, the binding interaction between EDB and calf thymus DNA (ctDNA) was assessed using molecular docking, UV-absorption spectroscopy, fluorescence spectroscopy, and circular dichroism (CD) spectroscopy. The absorption spectra indicated a hypochromic effect when EDB was combined with ctDNA. The binding constant (Ka) of EDB-ctDNA complex was calculated as 7.84 x 103 M-1, corresponds to a free energy change (Delta G) value of approximately-5.06 kcal/mol, indicating a moderate binding affinity. Fluorometric analysis revealed a static binding mechanism in the ground state, with a bimolecular enhancement constant (KB) of 7.56 x 1011 M- 1 . Displacement experiments demonstrated that EDB preferentially binds to the minor groove of ctDNA, with a Ksv value of 5.14 x 104 M-1. Further, KI quenching and CD spectroscopy confirmed the minor groove binding mode, which was associated with a decrease in the Tm from 68.28 degrees C to 65.84 degrees C, reflecting a destabilizing effect on DNA helix. Molecular docking supported these findings, showing that EDB exhibits a strong affinity for the minor groove of ctDNA and hydrogen bonding and Vander Waal interactions are the major forces involved in the binding. These results suggest that EDB primarily binds to the minor groove of ctDNA, which may play a role in its anticancer activity.

Aflatoxin B-1 (AFB(1)), a potent mutagen, is synthesized by Aspergillus parasiticus and Aspergillus flavus. Human serum albumin (HSA) is a globular protein with diverse roles. As AFB(1) is ingested with food and is transported in the body via blood, it becomes pertinent to comprehend the effect of the binding of this toxin on the structure and conformation of HSA, which may help to get insight into the toxic effect of the exposure of the mycotoxin. In this study, multi-spectroscopic approaches have been used to evaluate the binding efficiency of AFB(1) with both the native HSA (nHSA) and the glycated HSA (gHSA). Steady-state fluorescence spectroscopy reveals the static type of fluorescence quenching in the fluorescence emission spectra of nHSA and gHSA in the presence of AFB(1). The binding constant (K-b) is calculated to be 6.88 x 10(4) M-1 for nHSA, while a reduced K-b value of 2.95 x 10(4) M-1 has been obtained for gHSA. The circular dichroism study confirms the change in the secondary structure of nHSA and gHSA in the presence of AFB(1), followed by alterations in the melting temperature (T-m) of nHSA and gHSA. In silico computational findings envisaged the amino acid residues and bonds involved in the binding of nHSA and gHSA with AFB(1). The comprehensive study analyzes the binding effectiveness of AFB(1) with nHSA and gHSA and shows reduced binding of AFB(1) to gHSA.Communicated by Ramaswamy H. Sarma

Pesticides have adverse effects on the cellular functionality, which may trigger myriad of health consequences. However, pesticides-mediated toxicity in the endothelial cells (ECs) is still elusive. Hence, in this study, we have used human umbilical vein endothelial cells (HUVECs) as a model to quantify the cytotoxicity and genotoxicity of four pesticides (methomyl, carbaryl, metalaxyl, and pendimethalin). In the MTT assay, HUVECs exposed to methomyl, carbaryl, metalaxyl, and pendimethalin demonstrated significant proliferation inhibition only at higher concentrations (500 and 1000 μM). Likewise, neutral red uptake (NRU) assay also showed proliferation inhibition of HUVECs at 500 and 1000 μM by the four pesticides, confirming lysosomal fragility. HUVECs exposed to the four pesticides significantly increased the level of intracellular reactive oxygen species (ROS). Comet assay and flow cytometric data exhibited DNA damage and apoptotic cell death in HUVECs after 24 h of exposure with methomyl, metalaxyl, carbaryl, and pendimethalin. This is a first study on HUVECs signifying the cytotoxic-genotoxic and apoptotic potential of carbamate insecticides (methomyl and carbaryl), fungicide (metalaxyl), and herbicide (pendimethalin). Overall, these pesticides may affect ECs functions and angiogenesis; nonetheless, mechanistic studies are warranted from the perspective of vascular biology using in vivo test models.

The current study for the first time demonstrates the interference of a free-living, N-2 -fixing, and nanoparticle (NP) tolerant Azotobacter salinestris strain ASM recovered from metal-polluted soil with tomato plant-metal oxide NPs (ZnO, CuO, Al2O3 , and TiO2) interactions in a sandy clay loam soil system with bulk materials as control. Tomato plants were grown till full maturity in soils amended with 20-2000 mg kg(-1) of each metal-oxide NP with and without seed biopriming and root-inoculation of A. salinestris. A. salinestris was found metabolically active, producing considerably high amounts of bioactive indole-3-acetic-acid, morphologically unaffected, and with low alteration of cell membrane permeability under 125-1500 mu gml(-1) of NPs. However, ZnO-NPs slightly alter bacterial membrane permeability. Besides, A. salinestris secreted significantly higher amounts of extracellular polymeric substance (EPS) even under NP exposure, which could entrap the NPs and form metal-EPS complex as revealed and quantified by SEM-EDX. NPs were also found adsorbed on bacterial biomass. EPS stabilized the NPs and provided negative zeta potential to NPs. Following soil application, A. salinestris improved the plant performance and augmented the yield of tomato fruits and lycopene content even in NPs stressed soils. Interestingly, A. salinestris inoculation enhanced photosynthetic pigment formation, flower attributes, plant and fruit biomass, and reduced proline level. Bacterial inoculation also reduced the NP's uptake and accumulation significantly in vegetative organs and fruits. The organ wise order of NP's internalization was roots > shoots > fruits. Conclusively, A. salinestris inoculation could be an alternative to increase the production of tomato in metal-oxide NPs contaminated soils. (C) 2020 Elsevier Ltd. All rights reserved.

AIMS:Globally, scientists are working to find more efficient antimicrobial drugs to treat microbial infections and kill drug-resistant bacteria.BACKGROUND:Despite the availability of numerous antimicrobial drugs, bacterial infections still pose a serious threat to global health. A constant decline in the effectiveness of antibiotics owing to their repeated exposure as well as a short-lasting antimicrobial activity led to the demand for developing novel therapeutic agents capable of controlling microbial infections.OBJECTIVE:In this study, we report the antimicrobial activity of chemically synthesized silver nanoparticles (cAgNPs) augmented with ampicillin (amp) in order to increase antimicrobial response against Escherichia coli (gram -ve), Staphylococcus aureus (gram +ve) and Streptococcus mutans (gram +ve).METHODS:Nanostructure, colloidal stability, morphology and size of cAgNPs before and after functionalization were explored by UV-vis spectroscopy, FT-IR, zeta potential and TEM. The formation and functionalization of cAgNPs were confirmed from UV-vis spectroscopy and FT-IR patterns. From TEM, the average sizes of cAgNPs and cAgNP-amp were found to be 13 and 7.8 nm, respectively, and change in colloidal stability after augmentation was confirmed from zeta potential values. The antimicrobial efficacies of cAgNP-amp and cAgNPs against E. coli S. aureus and S. mutans were studied by determining Minimum Inhibitory Concentrations (MICs), zone of inhibition, assessment of viable and non-viable bacterial cells and quantitative assessment of biofilm.RESULTS & DISCUSSION:Our results revealed cAgNP-amp to be highly bactericidal compared to cAgNPs or amp alone. The nano-toxicity studies indicated cAgNP-amp to be less toxic compared to cAgNPs alone.CONCLUSION:This study manifested that cAgNPs show synergistic antimicrobial effects when they get functionalized with amp suggesting their application in curing long-term bacterial infections.

Expanding applications of metal-based nanoparticles (NPs) in industry and agriculture have influenced agro-ecosystems. However, relatively little is known about the bioaccumulation, distribution, and phytotoxicity of ZnO-NPs, CuO-NPs, ZnO-bulk, CuO-bulk, Zn2+, or Cu2+ in maize. Plants were exposed to 0.05-2 mg ml(-1) or g(-1) of six tested materials in agar (7 days) in hydroponic medium (20 days), or sandy-clay-loam soil (20 or 40 days). Seed germination, emergence and lengths of plumules, principal and seminal roots were significantly inhibited by ZnO-NPs, CuO-NPs, Zn2+, and Cu2+. Toxicity was more pronounced in hydroponic culture than in soil, and perceptible alterations in biomolecules were evident. ICP-MS analysis exhibited progressive uptake of metals while morphological, elemental, and surface/deeper scanning showed translocation and distribution of NPs in tissues. Tested materials induced enhanced superoxide radical production, lipid peroxidation, and antioxidant enzymes and praline levels. Exposure significantly reduced P-accumulation, photosynthesis, and protein production. Zn2+ and Cu2+ were found to be more toxic than NPs. Compared to 20 days exposure in soil, toxicity slightly increased after 40 days. ZnO-NPs and CuO-NPs increased apoptotic sub-G1 population by 22.4% and 38%, respectively. These results provide a better understanding of the mechanistic aspects responsible for the nanotoxicities of ZnO- and CuO-NPs in maize.

Multi-drug resistant (MDR) bacterial cells embedded in biofilm matrices can lead to the development of chronic cariogenesis. Here, we isolated and identified three Gram-positive MDR oral cocci, (1) SJM-04, (2) SJM-38, and (3) SJM-65, and characterized them morphologically, biochemically, and by 16S rRNA gene-based phylogenetic analysis as Georgenia sp., Staphylococcus saprophyticus, and Rothia mucilaginosa, respectively. These three oral isolates exhibited antibiotic-resistance against nalidixic acid, tetracycline, cefuroxime, methicillin, and ceftazidime. Furthermore, these Gram positive MDR oral cocci showed significant (p < 0.05) variations in their biofilm forming ability under different physicochemical conditions, that is, at temperatures of 28, 30, and 42 °C, pH of 6.4, 7.4, and 8.4, and NaCl concentrations from 200 to 1000 µg/mL. Exposure of oral isolates to TiO2NPs (14.7 nm) significantly (p < 0.05) reduced planktonic cell viability and biofilm formation in a concentration-dependent manner, which was confirmed by observing biofilm architecture by scanning electron microscopy (SEM) and optical microscopy. Overall, these results have important implications for the use of tetragonal anatase phase TiO2NPs (size range 5–25 nm, crystalline size 13.7 nm, and spherical shape) as an oral antibiofilm agent against Gram positive cocci infections. We suggest that TiO2NPs pave the way for further applications in oral mouthwash formulations and antibiofilm dental coatings.

We have applied a green approach employing the Aloe vera bioactives to encapsulate the hematite nanoparticles (ALE-alpha-Fe(2)O(3)NPs), and invested its potential to kill human breast cancer cells (MCF-7). Cytotoxicity analysis by [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)] (MTT) and neutral red uptake (NRU) assays showed 36% and 33% reduction in cell viability at 100 mu g/ml of ALE-alpha-Fe(2)O(3)NPs. Relative to untreated control, flow cytometric (FCM) analysis revealed 68.97% greater internalization of ALE-alpha-Fe(2)O(3)NPs in MCF-7 cells. FCM study further confirmed ALE-alpha-Fe(2)O(3)NPs induced reduction in mitochondrial membrane potential (Delta Psi m), and increase in intracellular reactive oxygen species (ROS). MCF-7 cells treated with ALE-alpha-Fe(2)O(3)NPs demonstrated DNA damage quantified by the comet assay. MCF-7 cells explicitly showed an increase in sub-G1 peak (36.3%) at 100 mu g/ml of ALE-alpha-Fe(2)O(3)NPs, confirming apoptotic cell death. qPCR data of apoptotic genes (p53, bax, caspase-3 and caspase-9) in MCF-7 cells showed enhanced upregulation upon ALE-alpha-Fe(2)O(3)NPs exposure. Overall, our data give a comprehensive, safe, cost-effective, and scalable biogenic nano-formulation of ALE-alpha-Fe(2)O(3)NPs for its putative clinical applications as anti-cancer drug.

The unregulated discharge of nanoparticles (NPs) from various nanotechnology industries into the environment is expected to alter the composition and physiological functions of soil microbiota. Considering this knowledge gap, the impact of five NPs (Ag, ZnO, CuO, Al2O3, and TiO2) differing in size and morphology on growth behavior and physiological activity of Azotobacter chroococcum, Bacillus thuringiensis, Pseudomonas mosselii, and Sinorhizobium meliloti were investigated. Various biochemical and microscopic approaches were adopted. Interestingly, all bacterial strains were found sensitive to Ag-NPs and ZnO-NPs but showed tolerance toward CuO, Al2O3, and TiO2-NPs. The loss of cellular respiration due to NPs was coupled with a reduction in population size. ZnO-NPs at 387.5 μg mL-1 had a maximum inhibitory impact on A. chroococcum and reduced its population by 72%. Under Ag-NP stress, the reduction in IAA secretion by bacterial strains followed the order S. meliloti (74%) > P. mosselii (63%) > A. chroococcum (49%). The surface of bacterial cells had small- or large-sized aggregates of NPs. Also, numerous gaps, pits, fragmented, and disorganized cell envelopes were visible. Additionally, a treated cell surface appeared corrugated with depressions and alteration in cell length and a strong heterogeneity was noticed under atomic force microscopy (AFM). For instance, NPs induced cell roughness for P. mosselii followed the order 12.6 nm (control) > 58 nm (Ag-NPs) > 41 nm (ZnO-NPs). TEM analysis showed aberrant morphology, cracking, and disruption of the cell envelope with extracellular electron-dense materials. Increased permeability of the inner cell membrane caused cell death and lowered EPS production. Ag-NPs and ZnO-NPs also disrupted the surface adhering ability of bacteria, which varied with time and concentration of NPs. Conclusively, a plausible mechanism of NP toxicity to bacteria has been proposed to understand the mechanistic basis of ecological interaction between NPs and resourceful bacteria. These results also emphasize to develop strategies for the safe disposal of NPs.

This study demonstrates a comprehensive and cost-effective one-step rapid bio-fabrication of Eucalyptus globulus leaf extract (ELE) bio-actives functionalized copper oxide nanoparticles (CuONPs); and analyze its apoptotic and toxic effects in human breast cancer (MCF-7) cells and Aspergillus flavus. The state-of-art characterization data confirmed the thermal-stability of (i) ELE-CuONPs and (ii) surface associated ELE bio-active compounds bearing characteristic functional groups (aromatic-OH, polymeric-OH, C-O, and C=O) over a range of conventional temperatures (30 degrees C-80 degrees C), and microwave (MW) heat (140 degrees C). The MW accelerated ELE-CuONPs (16.9 nm) treated (25 - 100 mu g/ml) MCF-7 cells showed a significant (p < 0.05) reduction in viability due to the dysfunction of mitochondrial membrane potential, intracellular ROS accumulation, and disruption in normal cell cycle progression. Moreover, transcriptional up-regulation of mRNA expression of p53 (8.8 fold), bax (1.42 fold), caspase-3 (2.42 fold), and caspase-9 (3.34 fold) genes in the MCF-7 cells confirmed a mechanistic anti-cancer landscape of synthesized ELE-CuONPs. Furthermore, ELE-CuONPs inhibited sclerotia germination and growth of A. flavus. Conclusively, this study is novel in better demonstrating the formation of ELE-CuONPs that meets the principles of green chemistry. These findings can be used to develop strategies for the management of cancer and fungal infections affecting human health.

In the past two decades, increased production and usage of metallic nanoparticles (NPs) have inevitably increased their discharge into the different compartments of the environment, which ultimately paved the way for their uptake and accumulation in various trophic levels of the food chain. Due to these issues, several questions have been raised on the usage of NPs in everyday life and have become a matter of public health concern. Among the metallic NPs, Cu-based NPs have gained popularity due to their cost-effectiveness and multifarious promising uses. Several studies in the past represented the phytotoxicity of Cu-based NPs on plants. However, comprehensive knowledge is still lacking. Additionally, the impact of Cu-based NPs on soil organisms such as agriculturally important microbes, fungi, mycorrhiza, nematode, and earthworms is poorly studied. This review article critically analyses the literature data to achieve a more comprehensive knowledge on the toxicological profile of Cu-based NPs and increase our understanding of the effects of Cu-based NPs on aquatic and terrestrial plants as well as on soil microbial communities. The underlying mechanism of biotransformation of Cu-based NPs and the process of their penetration into plants have also been discussed herein. Overall, this review could provide valuable information to design rules and regulations for the safe disposal of Cu-based NPs into a sustainable environment.

Chemically synthesized copper oxide nanoparticles (CuONPs) involve the generation of toxic products, which narrowed its biological application. Hence, we have developed a one-pot, green method for CuONP production employing the leaf extract of Cymbopogon citratus (CLE). Gas chromatography-mass spectrometry (GC-MS) analysis confirmed the capping of CuONPs by CLE esters (CLE-CuONPs). Fourier-transform infrared (FTIR) showed phenolics, sugars, and proteins mediated nucleation and stability of CLE-CuONPs. X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed CLE-CuONPs between 11.4 to 14.5 nm. Staphylococcus aureus-1 (MRSA-1), Staphylococcus aureus-2 (MSSA-2) exposed to CLE-CuONPs (1500 µg/mL) showed 51.4%, 32.41% survival, while Escherichia coli-336 (E. coli-336) exposed to 1000 µg/mL CLE-CuONPs showed 45.27% survival. Scanning electron microscopy (SEM) of CLE-CuONPs treated E. coli-336, MSSA-2 and MRSA-1 showed morphological deformations. The biofilm production by E. coli-336 and MRSA-1 also declined to 33.0 ± 3.2% and 49.0 ± 3.1% at 2000 µg/mL of CLE-CuONPs. Atomic absorption spectroscopy (AAS) showed 22.80 ± 2.6%, 19.2 ± 4.2%, and 16.2 ± 3.6% accumulation of Cu2+ in E. coli-336, MSSA-2, and MRSA-1. Overall, the data exhibited excellent antibacterial and antibiofilm efficacies of esters functionalized CLE-CuONPs, indicating its putative application as a novel nano-antibiotic against multi drug resistance (MDR) pathogenic clinical isolates.

The fast-growing use of nano-based products without proper care has led to a major public health concern. Nanomaterials contaminating the environment pose serious threat to the productivity of plants and via food chain to human health. Realizing these, four vegetable crops, radish, cucumber, tomato, and alfalfa, were exposed to varying concentrations of heavy metal oxide (TiO2, ZnO, Al2O3 and CuO) submicron or bulk (BPs) and nanoparticles (NPs) to assess their impact on relative seed germination (RSG), seed surface adsorption, root/shoot tolerance index (RTI/STI), bioaccumulation, and metallothioneins (MTs) production. The results revealed a clear inhibition of RSG, RTI, and STI, which, however, varied between species of metal-specific nanoparticles and plants. SEM and EDX analyses showed significant adsorption of MONP agglomerates on seed surfaces. The concentration of metals detected by EDX differed among vegetables. Among the metals, Al, Cu, Ti, and Zn were found maximum in alfalfa (12.46%), tomato (23.2%), cucumber (6.32%) and radish (21.74%). Of the four metal oxides, ZnO was found most inhibitory to all vegetables and was followed by CuO. The absorption/accumulation of undesirable levels of MONPs in seeds and seedlings differed with variation in dose rates, and was found to be maximum (1748-2254 μg g-1 dry weight) in ZnO-NPs application. Among MONPs, the uptake of TiO2 was minimum (2 to 140 μg g-1) in radish seedlings. The concentration of MTs induced by ZnO-NPs, ZnO-BPs, and CuO-NPs ranged between 52 and 136 μ mol MTs g-1 FW in vegetal organs. Conclusively, the present findings indicated that both the nanosize and chemical composition of MONPs are equally dangerous for vegetable production. Hence, the accumulation of MONPs, specifically ZnO and CuO, in edible plant organs in reasonable amounts poses a potential environmental risk which, however, requires urgent attention to circumvent such toxic problems.