Role of proteins in the biosynthesis and functioning of metallic nanoparticles.

Proteins are known to play important roles in the biosynthesis of metallic nanoparticles (NPs), which are biological substitutes for conventionally used chemical capping and stabilizing agents. When a pristine nanoparticle comes in contact with a biological media or system, a bimolecular layer is formed on the surface of the nanoparticle and is primarily composed of proteins. The role of proteins in the biosynthesis and further uptake, translocation, and bio-recognition of nanoparticles is documented in the literature. But, a complete understanding has not been achieved concerning the mechanism for protein-mediated nanoparticle biosynthesis and the role proteins play in the interaction and recognition of nanoparticles, aiding its uptake and assimilation into the biological system. This review critically evaluates the knowledge and gaps in the protein-mediated biosynthesis of nanoparticles. In particular, we review the role of proteins in multiple facets of metallic nanoparticle biosynthesis, the interaction of proteins with metallic nanoparticles for recognition and interaction with cells, and the toxic potential of protein-nanoparticle complexes when presented to the cell.

Nano-Enabled sensors for detection of arsenic in water.

The elevated cases of arsenic contamination reported across the globe have made its early detection and remediation an active area of research. Although, the World Health Organisation has set the maximum provisional value for arsenic in drinking water at 10 parts per billion, yet concentrations as high as 5000 parts per billion are still reported. In human beings, chronic arsenic exposure can culminate into lethal diseases such as cancer. Thus, there is a need for urgent emergence of efficient and reliable detection system. This paper offers an overview of the state-of-art knowledge on current arsenic detection mechanisms. The central agenda of this paper is to develop an understanding into the nano-enabled methods for arsenic detection with an emphasis on strategic fabrication of nanostructures and the modulation of nanomaterial chemistry in order to strengthen the knowledge into novel nano-enabled solutions for arsenic contamination. Towards the end prospects for arsenic detection in water are also prompted.

Non-Toxic and Ultra-Small Biosilver Nanoclusters Trigger Apoptotic Cell Death in Fluconazole-Resistant Candida albicans via Ras Signaling.

Silver-based nanostructures are suitable for many biomedical applications, but to be useful therapeutic agents, the high toxicity of these nanomaterials must be eliminated. Here, we biosynthesize nontoxic and ultra-small silver nanoclusters (rsAg@NCs) using metabolites of usnioid lichen (a symbiotic association of algae and fungi) that exhibit excellent antimicrobial activity against fluconazole (FCZ)-resistant Candida albicans that is many times higher than chemically synthesized silver nanoparticles (AgNPs) and FCZ. The rsAg@NCs trigger apoptosis via reactive oxygen species accumulation that leads to the loss of mitochondrial membrane potential, DNA fragmentation, chromosomal condensation, and the activation of metacaspases. The proteomic analysis clearly demonstrates that rsAg@NCs exposure significantly alters protein expression. Most remarkable among the down-regulated proteins are those related to glycolysis, metabolism, free radical scavenging, anti-apoptosis, and mitochondrial function. In contrast, proteins involved in plasma membrane function, oxidative stress, cell death, and apoptosis were upregulated. Eventually, we also established that the apoptosis-inducing potential of rsAg@NCs is due to the activation of Ras signaling, which confirms their application in combating FCZ-resistant C. albicans infections.

Effect of cabergoline alginate nanocomposite on the transgenic Drosophila melanogaster model of Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra of the midbrain. Dopamine agonists help the patients with PD by reversing the dopamine depletion and related motor deficits. In the present work, cabergoline, a potent ergot dopamine agonist, was given in the form of cabergoline alginate nanocomposite (CANC) to the PD model flies to study its effects on climbing ability, activity pattern, life span, lipid peroxidation, glutathione (GSH) content, glutathione-S-transferase (GST) activity, dopamine content, protein carbonyl content, mean gray-scale values, and caspase-3 and caspase-9 activities. Cabergoline alginate nanocomposite was synthesized by adding the cabergoline solution in the warm aqueous solution of sodium alginate; The synthesized CANC was characterized using fourier transform (FTIR) infrared spectroscopy, transmission electron microscopy (TEM), and UV-Visible spectroscopic techniques. The synthesized CANC having the final doses of 1, 2, and 3 µM was supplemented with diet and the flies were allowed to feed on it for 24 days. Cabergoline alginate nanocomposite significantly increases climbing ability, reduces lipid peroxidation, GST activity, protein carbonyl content, caspase 3/9 activity, mean gray-scale values, and increases the GSH as well as dopamine content in a dose-dependent manner. The results of this study suggest that CANC is potent in delaying and reducing the symptoms of PD.

Development of a novel myconanomining approach for the recovery of agriculturally important elements from jarosite waste.

In this study, an ecofriendly and economically viable waste management approach have been attempted towards the biosynthesis of agriculturally important nanoparticles from jarosite waste. Aspergillus terreus strain J4 isolated from jarosite (waste from Debari Zinc Smelter, Udaipur, India), showed good leaching efficiency along with nanoparticles (NPs) formation under ambient conditions. Fourier-transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM) confirmed the formation of NPs. Energy dispersive X-ray spectroscopy (EDX analysis) showed strong signals for zinc, iron, calcium and magnesium, with these materials being leached out. TEM analysis and high resolution transmission electron microscopy (HRTEM) showed semi-quasi spherical particles having average size of 10-50nm. Thus, a novel biomethodology was developed using fungal cell-free extract for bioleaching and subsequently nanoconversion of the waste materials into nanostructured form. These biosynthesized nanoparticles were tested for their efficacy on seed emergence activity of wheat (Triticum aestivum) seeds and showed enhanced growth at concentration of 20ppm. These nanomaterials are expected to enhance plant growth properties and being targeted as additives in soil fertility and crop productivity enhancement.

An Aspergillus aculateus strain was capable of producing agriculturally useful nanoparticles via bioremediation of iron ore tailings.

Mining waste such as iron ore tailing is environmentally hazardous, encouraging researchers to develop effective bioremediation technologies. Among the microbial isolates collected from iron ore tailings, Aspergillus aculeatus (strain T6) showed good leaching efficiency and produced iron-containing nanoparticles under ambient conditions. This strain can convert iron ore tailing waste into agriculturally useful nanoparticles. Fourier-transform Infrared Spectroscopy (FT-IR analysis) established the at the particles are protein coated, with energy dispersive X-ray Spectroscopy (EDX analysis) showing strong signals for iron. Transmission Electron Microscopy (TEM analysis) showed semi-quasi spherical particles having average size of 15 ±â€¯5 nm. These biosynthesized nanoparticles when tested for their efficacy on seed emergence activity of mungbean (Vigna radiata) seeds, and enhanced plant growth at 10 and 20 ppm.

Intracellular Synthesis of Gold Nanoparticles Using an Ectomycorrhizal Strain EM-1083 of Laccaria fraterna and Its Nanoanti-quorum Sensing Potential Against Pseudomonas aeruginosa.

In this research work different shapes and sizes of gold nanoparticles (AuNPs) were synthesized through an intracellular biogenic approach, exploiting the chloroauric acid reducing and Au0 stabilizing potential of Laccaria fraterna EM-1083 mycelia. The intracellularly synthesized AuNPs exhibits anti-quorum sensing inhibitory potential against Pseudomonas aeruginosa. The synthesized AuNPs were characterized using UV-visible spectroscopy; transmission electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The characterization proved that the successful synthesis of highly stable crystalline AuNPs with various shapes. Here we tested inhibitory activity of AuNPs on QS-regulated biofilm development and pyocyanin production traits of P. aeruginosa. The qualitative and quantitative data demonstrated that AuNPs significantly inhibited the biofilm formation and pyocyanin production. In summary, our results signify the future use of intracellularly synthesized AuNPs in P. aeruginosa mediated diseases.

Potential of biosynthesized silver nanoparticles using Stenotrophomonas sp. BHU-S7 (MTCC 5978) for management of soil-borne and foliar phytopathogens.

Stenotrophomonas sp. is emerging as a popular microbe of global concern with various potential ecological roles. Biosynthesis of gold and silver nanoparticles (AgNPs) using this bacterial strain has shown promising applications in life sciences. However, there is no report on efficient agricultural applications of biosynthesized AgNPs using Stenotrophomonas sp. In this regard, successful biosynthesis of AgNPs using Stenotrophomonas sp. BHU-S7 (MTCC 5978) was monitored by Uv-visible spectrum showing surface plasmon resonance (SPR) peak at 440 nm. The biosynthesized AgNPs were spherical with an average mean size of ~12 nm. The antifungal efficacy of biosynthesized AgNPs against foliar and soil-borne phytopathogens was observed. The inhibitory impact of AgNPs (2, 4, 10 µg/ml) on conidial germination was recorded under in vitro conditions. Interestingly, sclerotia of Sclerotium rolfsii exposed to AgNPs failed to germinate on PDA medium and in soil system. Moreover, AgNPs treatment successfully managed collar rot of chickpea caused by S. rolfsii under greenhouse conditions. The reduced sclerotia germination, phenolic acids induction, altered lignification and H2O2 production was observed to be the probable mechanisms providing protection to chickpea against S. rolfsii. Our data revealed that AgNPs treated plants are better equipped to cope with pathogen challenge pointing towards their robust applications in plant disease management.

Bactericidal, quorum quenching and anti-biofilm nanofactories: a new niche for nanotechnologists.

Despite several conventional potent antibacterial therapies, bacterial infections pose a significant threat to human health because they are emerging as the leading cause of death worldwide. Due to the development of antibiotic resistance in bacteria, there is a pressing demand to discover novel approaches for developing more effective therapies to treat multidrug-resistant bacterial strains and biofilm-associated infections. Therefore, attention has been especially devoted to a new and emerging branch of science "nanotechnology" to design non-conventional antimicrobial chemotherapies. A range of nanomaterials and nano-sized carriers for conventional antimicrobial agents have fully justified their potential to combat bacterial diseases by reducing cell viability, by attenuating quorum sensing, and by inhibiting/or eradicating biofilms. This communication summarizes emerging nano-antimicrobial therapies in treating bacterial infections, particularly using antibacterial, quorum quenching, and anti-biofilm nanomaterials as new approaches to tackle the current challenges in combating infectious diseases.

Bactericidal, quorum quenching and anti-biofilm nanofactories: a new niche for nanotechnologists

Despite several conventional potent antibacterial therapies, bacterial infections pose a significant threat to human health because they are emerging as the leading cause of death worldwide. Due to the development of antibiotic resistance in bacteria, there is a pressing demand to discover novel approaches for developing more effective therapies to treat multidrug-resistant bacterial strains and biofilm-associated infections. Therefore, attention has been especially devoted to a new and emerging branch of science "nanotechnology" to design non-conventional antimicrobial chemotherapies. A range of nanomaterials and nano-sized carriers for conventional antimicrobial agents have fully justified their potential to combat bacterial diseases by reducing cell viability, by attenuating quorum sensing, and by inhibiting/or eradicating biofilms. This communication summarizes emerging nano-antimicrobial therapies in treating bacterial infections, particularly using antibacterial, quorum quenching, and anti-biofilm nanomaterials as new approaches to tackle the current challenges in combating infectious diseases.

Effect of bromocriptine alginate nanocomposite (BANC) on a transgenic Drosophila model of Parkinson's disease.

The effect of bromocriptine, a dopamine agonist, administered in the form of bromocriptine alginate nanocomposite (BANC) was studied on Parkinson's disease (PD) model flies. The synthesized BANC was subject to characterization and, at a final concentration of 0.5, 1.0 and 1.5 µM, was mixed in diet. The PD flies were allowed to feed on it for 24 days. A significant dose-dependent delay in the loss of climbing activity and activity pattern was observed in PD flies exposed to 0.5, 1.0 and 1.5 µM BANC. The PD flies exposed to BANC also showed a significant reduction in lipid peroxidation and glutathione-S-transferase activity, and an increase in glutathione content. However, no gross morphological changes were observed in the brains of PD flies compared with controls. The results suggest that BANC is effective in reducing the PD symptoms in these transgenic flies.

Kinetic Study on Mutagenic Chemical Degradation through Three Pot Synthesiszed Graphene@ZnO Nanocomposite.

The study was taken up with the objective to synthesize graphene-zinc oxide nano particles (NPs) nanocomposite (Gr@ZnO-Nc) via In-situ synthesis method. The structural, optical, thermal, electrical and photocatalytic properties of the synthesized Gr@ZnO-Nc were studied. The characterization data confirmed that the ZnO NPs were successfully incorporated into the graphene sheets. Further, TGA/DTA results exhibited an enhanced thermal stability of the Gr@ZnO-Nc compared with the graphene. The Gr@ZnO-Nc, graphene sheets were uniformly wrapped by ZnO NPs, which can protect graphene and delay their oxidation in air. The synthesized Gr@ZnO-Nc was used for the efficient photodegradation of a carcinogenic methyl orange (MO) dye. The results exhibited promising photodegradation of the MO dye under UV light irradiation through the production of reactive oxygen species (ROS). The promising effect of Gr@ZnO-Nc on the photodegradation properties was conferred by the large surface area which increased adsorption capacity, and the strong electron transfer ability. Thus, it is encouraging to conclude that the synthesized Gr@ZnO-Nc has environmental significance with its utility in remediation in the hazardous MO dye.

Anthelmintic Effect of Biocompatible Zinc Oxide Nanoparticles (ZnO NPs) on Gigantocotyle explanatum, a Neglected Parasite of Indian Water Buffalo.

Helminth parasites of veterinary importance cause huge revenue losses to agrarian economy worldwide. With the emergence of drug resistance against the current formulations, there is a need to focus on the alternative approaches in order to control this menace. In the present study, biocompatible zinc oxide nanoparticles (ZnO NPs) were used to see their in vitro effect on the biliary amphistomes, Gigantocotyle explanatum, infecting Bubalus bubalis because these nanoparticles are involved in generation of free radicals that induce oxidative stress, resulting in disruption of cellular machinery. The ZnO NPs were synthesized by using egg albumin as a biotemplate and subsequently characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction and Spectrophotometrical, which showed that ZnO NPs were highly purified wurtzite type polycrystals, with a mean size of 16.7 nm. When the parasites were treated with lower concentrations (0.004% and 0.008%) of the ZnO NPs, the worms mounted a protective response by stimulating the antioxidant system but the treatment of G. explanatum with 0.012% ZnO NPs produced significant inhibition of the antioxidant enzymes like superoxide dismutase (SOD) (p< 0.05) and glutathione S- transferase (GST) (p<0.01), while the level of malondialdehyde (MDA), a lipid peroxidation marker, was significantly (p< 0.01) elevated. SEM and histopathology revealed pronounced tegumental damage showing the disruption of surface papillae and the annulations, particularly in the posterior region near acetabulum. The under expression of a number of polypeptides, loss of worm motility in a time dependent manner, further reflect strong anthelmintic potential of ZnO NPs. It can be concluded that the anthelmintic effect might be due to the production of reactive oxygen species that target a variety of macromolecules such as nucleic acid, protein and lipids which are involved in different cellular processes.

Toxic potential of copper-doped ZnO nanoparticles in Drosophila melanogaster (Oregon R).

AIMS: In the present study, copper-doped ZnO nanoparticles (doped ZnO NPs Cu) were synthesized, characterized and evaluated for their possible toxic effects in Drosophila melanogaster (Oregon R). METHODS AND RESULTS: X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectrometry confirm the formation of doped ZnO NPs Cu. Doped ZnO NPs Cu (3%) were mixed in the diet at final concentrations of 1, 2, 4 and 8 µg/µl. The starved male flies were allowed to feed on it for 4 days. After completion of the desired duration, climbing ability, activity pattern, activity of acetylcholinesterase (AChE), glutathione (GSH), glutathione-S-transferase (GST), lipid peroxidation (LPO), total protein content and caspases were studied. SDS-PAGE was also performed for whole fly homogenate of control as well as treated flies. No loss in the climbing and activity pattern was observed at the selected doses of doped ZnO NPs Cu. No significant change in the levels of AChE, GSH, GST, LPO, caspase 9/3 and total protein content was observed. The brain sections showed no gross changes in the structure and SDS-PAGE patterns also revealed no change in the protein expression. CONCLUSIONS: The results suggest that doped ZnO NPs Cu are non-toxic at 1, 2, 4 and 8 µg/µl of concentration in D. melanogaster.

Magnetically recyclable Ni0.5Zn0.5Fe2O4/Zn0.95Ni0.05O nano-photocatalyst: structural, optical, magnetic and photocatalytic properties.

A novel visible light active and magnetically separable nanophotocatalyst, Ni0.5Zn0.5Fe2O4/Zn0.95Ni0.05O (denoted as NZF@Z), with varying amount of Ni0.5Zn0.5Fe2O4, has been synthesized by egg albumen assisted sol gel technique. The structural, optical, magnetic, and photocatalytic properties have been studied by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), fourier transform infrared spectroscopy (FTIR), UV-visible (UV-Vis) spectroscopy, and vibrating sample magnetometry (VSM) techniques. Powder XRD, TEM, FTIR and energy dispersive spectroscopic (EDS) analyses confirm coexistence of Ni0.5Zn0.5Fe2O4 and Zn0.95Ni0.05O phases in the catalyst. Crystallite sizes of Ni0.5Zn0.5Fe2O4 and Zn0.95Ni0.05O in pure phases and nanocomposites, estimated from Debye-Scherrer equation, are found to be around 15-25 nm. The estimated particle sizes from TEM and FESEM data are ∼(22±6) nm. The calculated energy band gaps, obtained by Tauc relation from UV-Vis absorption spectra, of Zn0.95Ni0.05O, 15%NZF@Z, 40%NZF@Z and 60%NZF@Z are 2.95, 2.72, 2.64, and 2.54 eV respectively. Magnetic measurements (field (H) dependent magnetization (M)) show all samples to be super-paramagnetic in nature and saturation magnetizations (Ms) decrease with decreasing ferrite content in the nanocomposites. These novel nanocomposites show excellent photocatalytic activities on Rhodamin Dye.

Biosynthesis of stable antioxidant ZnO nanoparticles by Pseudomonas aeruginosa rhamnolipids.

During the last several years, various chemical methods have been used for synthesis of a variety of metal nanoparticles. Most of these methods pose severe environmental problems and biological risks; therefore the present study reports a biological route for synthesis of zinc oxide nanoparticles using Pseudomonas aeruginosa rhamnolipids (RLs) (denoted as RL@ZnO) and their antioxidant property. Formation of stable RL@ZnO nanoparticles gave mostly spherical particles with a particle size ranging from 35 to 80 nm. The RL@ZnO nanoparticles were characterized by UV-visible (UV-vis) spectroscopy, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and thermal gravimetric analysis. The UV-vis spectra presented a characteristic absorbance peak at ∼ 360 nm for synthesized RL@ZnO nanoparticles. The XRD spectrum showed that RL@ZnO nanoparticles are crystalline in nature and have typical wurtzite type polycrystals. Antioxidant potential of RL@ZnO nanoparticles was assessed through 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, and superoxide anion free radicals with varying concentration and time of the storage up to 15 months, while it was found to decline in bare ZnO nanoparticles. Similarly, the inhibitory effects on ß-carotene oxidation and lipid peroxidation were also observed. These results elucidate the significance of P. aeruginosa RL as effective stabilizing agents to develop surface protective ZnO nanoparticles, which can be used as promising antioxidants in biological system.

Toxic potential of synthesized graphene zinc oxide nanocomposite in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg9.

In the present study the graphene zinc oxide nanocomposite (GZNC) was synthesized, characterized, and evaluated for its toxic potential on third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9). The synthesized GZNC was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The GZNC in 0.1% dimethyl sulphoxide (DMSO) was sonicated for 10 minutes and the final concentrations 0.033, 0.099, 0.199, and 3.996 µg/µL of diet were established. The third instar larvae were allowed to feed on it separately for 24 and 48 hr. The hsp70 expression was measured by o-nitrophenyl-ß-D-galactopyranoside assay, tissue damage was measured by trypan blue exclusion test, and ß-galactosidase activity was monitored by in situ histochemical ß-galactosidase staining. Oxidative stress was monitored by performing lipid peroxidation assay and total protein estimation. Ethidium bromide/acridine orange staining was performed on midgut cells for apoptotic index and the comet assay was performed for the DNA damage. The results of the present study showed that the exposure of 0.199 and 3.996 µg/µL of GZNC was toxic for both 24 hr and 48 hr of exposure. The doses of 0.033 µg/µL and 0.099 of GZNC showed no toxic effects on its exposure to the third instar larvae for 24 hr as well as 48 hr of duration.

Biofabricated silver nanoparticles act as a strong fungicide against Bipolaris sorokiniana causing spot blotch disease in wheat.

The present study is focused on the extracellular synthesis of silver nanoparticles (AgNPs) using culture supernatant of an agriculturally important bacterium, Serratia sp. BHU-S4 and demonstrates its effective application for the management of spot blotch disease in wheat. The biosynthesis of AgNPs by Serratia sp. BHU-S4 (denoted as bsAgNPs) was monitored by UV-visible spectrum that showed the surface plasmon resonance (SPR) peak at 410 nm, an important characteristic of AgNPs. Furthermore, the structural, morphological, elemental, functional and thermal characterization of bsAgNPs was carried out using the X-ray diffraction (XRD), electron and atomic microscopies, energy dispersive X-ray (EDAX) spectrometer, FTIR spectroscopy and thermogravimetric analyzer (TGA), respectively. The bsAgNPs were spherical in shape with size range of ∼10 to 20 nm. The XRD and EDAX analysis confirmed successful biosynthesis and crystalline nature of AgNPs. The bsAgNPs exhibited strong antifungal activity against Bipolaris sorokiniana, the spot blotch pathogen of wheat. Interestingly, 2, 4 and 10 µg/ml concentrations of bsAgNPs accounted for complete inhibition of conidial germination, whereas in the absence of bsAgNPs, conidial germination was 100%. A detached leaf bioassay revealed prominent conidial germination on wheat leaves infected with B. sorokiniana conidial suspension alone, while the germination of conidia was totally inhibited when the leaves were treated with bsAgNPs. The results were further authenticated under green house conditions, where application of bsAgNPs significantly reduced B. sorokiniana infection in wheat plants. Histochemical staining revealed a significant role of bsAgNPs treatment in inducing lignin deposition in vascular bundles. In summary, our findings represent the efficient application of bsAgNPs in plant disease management, indicating the exciting possibilities of nanofungicide employing agriculturally important bacteria.

Dietary phytochemicals alter epigenetic events and signaling pathways for inhibition of metastasis cascade: phytoblockers of metastasis cascade.

Cancer metastasis is a multistep process in which a cancer cell spreads from the site of the primary lesion, passes through the circulatory system, and establishes a secondary tumor at a new nonadjacent organ or part. Inhibition of cancer progression by dietary phytochemicals (DPs) offers significant promise for reducing the incidence and mortality of cancer. Consumption of DPs in the diet has been linked to a decrease in the rate of metastatic cancer in a number of preclinical animal models and human epidemiological studies. DPs have been reported to modulate the numerous biological events including epigenetic events (noncoding micro-RNAs, histone modification, and DNA methylation) and multiple signaling transduction pathways (Wnt/ß-catenin, Notch, Sonic hedgehog, COX-2, EGFR, MAPK-ERK, JAK-STAT, Akt/PI3K/mTOR, NF-κB, AP-1, etc.), which can play a key role in regulation of metastasis cascade. Extensive studies have also been performed to determine the molecular mechanisms underlying antimetastatic activity of DPs, with results indicating that these DPs have significant inhibitory activity at nearly every step of the metastatic cascade. DPs have anticancer effects by inducing apoptosis and by inhibiting cell growth, migration, invasion, and angiogenesis. Growing evidence has also shown that these natural agents potentiate the efficacy of chemotherapy and radiotherapy through the regulation of multiple signaling pathways. In this review, we discuss the variety of molecular mechanisms by which DPs regulate metastatic cascade and highlight the potentials of these DPs as promising therapeutic inhibitors of cancer.

Evaluation of the toxic potential of graphene copper nanocomposite (GCNC) in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9.).

Graphene, a two-dimensional carbon sheet with single-atom thickness, have attracted the scientific world for its potential applications in various field including the biomedical areas. In the present study the graphene copper nanocomposite (GCNC) was synthesized, characterized and evaluated for its toxic potential on third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9) . The synthesized GCNC was analyzed by X-ray diffraction (XRD), scanning/transmission electron microscopy (SEM/TEM), atomic force microscopy (AFM), and fourier transform infrared spectroscopy (FTIR). The GCNC in 0.1% DMSO was sonicated for 10 min and the final concentration of 0.033, 0.099, 0.199 and 3.996 µg/µl of diet were established. The third instar larvae were allowed to feed on it separately for 24 and 48 hrs. The hsp70 expression was measured by O-nitrophenyl-ß-D-galactopyranoside assay, tissue damage by trypan blue exclusion test and ß-galactosidase activity was monitored by in situ histochemical ß-galactosidase staining. Oxidative stress was monitored by performing lipid peroxidation assay and total protein estimation. Ethidium bromide/acridine orange staining was performed on midgut cells for apoptotic index and the comet assay was performed for the DNA damage. The results of the present study showed that the exposure of 0.199 and 3.996 µg/µl of GCNC were toxic for 24 hr of exposure and for 48 hr of exposure: 0.099, 0.199 and 3.996 µg/µl of GCNC was toxic. The dose of 0.033 µg/µl of GCNC showed no toxic effects on its exposure to the third instar larvae for 24 hr as well as 48 hrs. This dose can be considered as No Observed Adverse Effect Level (NOAEL).