The Toxicity of Synthetic and Biogenic Selenium Nanoparticles on Human Brain Glioblastoma Cell Line: An in vitro Comparison

Background: Brain tumors can be serious and life-threatening when they are treated effectively. Many therapeutic approaches, such as chemotherapy, radiotherapy, and surgery have been used to treat brain tumors. In this regard, selenium supplements have been reported effective.Methods: Selenium Nanoparticles (SeNPs) were produced in two forms of synthetic and biogenic to evaluate their cytotoxicity on brain glioblastoma cell lines. A-172 cell line was cultured in DMEM medium. The cytotoxicity of the synthetic and biogenic SeNP was assessed by MTT assay. Results: There was a significant difference between the group treated with biogenic and synthetic SeNP compared with non-treated cells after 24, 48, and 72 h. Both biogenic and synthetic SeNP increased Bax gene and decreased Bcl-2 gene expression. Conclusion: It seems that biogenic SeNP was more lethal than its synthetic form. Therefore, it should be considered that the method of NP construction may be an important parameter for its bioactivity

Novel inhibitor discovery against aromatase through virtual screening and molecular dynamic simulation

Inhibition of aromatase (CYTP450) as a key enzyme in the estrogen biosynthesis could result in regression of estrogen-dependent tumors and even preventing the promotion of breast cancer. Although today potent steroid and non-steroid inhibitors of aromatase are available, isoflavanone derivatives as natural compounds with least side effects have been described as the candidate for a new generation of aromatase inhibitors. 2a as an isoflavanone derivative is the most potent inhibitor of aromatase, synthesized by Bonfield et al. (2012). In our computational study, the mentioned compound was used as the template for virtual screening. Between 286 selected compounds with 70 % of structural similarity to 2a, 150 of them showed lower docking energy in comparison with 2a. Compound 2a_1 with 11.2 kcal/mol had the lowest docking energy. Interaction of 2a_1 with aromatase was further investigated and compared with 2a and androstenedione (ASD) as a natural substrate of aromatase, through 20 ns of molecular dynamic simulation. Analysis of trajectories showed, while ASD interacts with aromatase through hydrogen bonds and 2a just interacts via hydrophobic forces, 2a_1 not only accommodates in the hydrophobic active site of aromatase in a suitable manner but it also makes a stable coordination with iron atom of aromatase heme group via OB

Acute and subacute toxicity of novel biogenic selenium nanoparticles in mice

Context: In the present investigation, acute and subacute toxicity of the biogenic Se nanoparticles (Se NPs) has been reported. Objective: To characterize the Se NPs produced by a bacterium species and to evaluate their toxicity and impact on clinical chemistry and hematological parameters of NMRI mice. Materials and methods: The Se NPs were prepared by Bacillus sp. MSh-1 in a culture medium containing SeO2 (1.26 mM) and their physiochemical properties investigated using TEM, XRD and FT-IR. The LD50 of Se NPs and SeO2 were determined and the subacute toxicity evaluated by orally administration of 0, 2.5, 5, 10 and 20 mg kg−1 of Se NPs to male mice for 14 consecutive days. Parameters of blood cells, AST, ALT, ALP, creatinine, BUN, cholesterol, bilirubin, triglyceride and CPK were experimentally measured. Results: The XRD and TEM analyses showed that the spherical NPs were amorphous, in the size range of 80–220 nm. The toxicological evaluation showed that the LD50 values of SeO2 and Se NPs were 7.3 and 198.1 mg kg−1, respectively. No biochemical changes were observed from the administration of 2.5, 5 and 10 mg kg−1 of Se NPs, but a dose of 20 mg kg−1 was accompanied with signs of toxicity including lower body weight and changes in clinical chemistry and hematological parameters. Conclusion: The biogenic Se NPs were less toxic than synthetic Se NPs and much less (26-fold) toxic than the SeO2, which demonstrates the important role of Bacillus sp. MSh-1 in conversion of a highly toxic Se compound to the less toxic Se NPs. Keywords: L

In Vitro Antiparasitic and Apoptotic Effects of Antimony Sulfide Nanoparticles on Leishmania infantum

Visceral leishmaniasis is one of the most important sever diseases in tropical and subtropical countries. In the present study the effects of antimony sulfide nanoparticles on Leishmania infantum in vitro were evaluated. Antimony sulfide NPs (Sb2S5) were synthesized by biologicalmethod fromSerratia marcescens bacteria. Then the cytotoxicity effects of different concentrations (5, 10, 25, 50, and 100 μg/mL) of this nanoparticle were assessed on promastigote and amastigote stages of L. infantum. MTTmethodwas used for verification results of promastigote assay. Finally, the percentages of apoptotic, necrotic, and viable cells were determined by flow cytometry. The results indicated the positive effectiveness of antimony sulfide NPs on proliferation of promastigote form. The IC50 (50% inhibitory concentration) of antimony sulfide NPs on promastigotes was calculated 50 μg/mL. The cytotoxicity effect was dose-dependent means by increasing the concentration of antimony sulfide NPs, the cytotoxicity curve was raised and the viability curve of the parasite dropped simultaneously. Moreover, the IC50 of antimony sulfide NPs on amastigote stage was calculated 25 μg/mL. On the other hand, however, antimony sulfide NPs have a low cytotoxicity effect on uninfected macrophages but it can induce apoptosis in promastigote stage at 3 of 4 concentrations

Effect of selenium supplementation with sodium selenite and selenium nanoparticles on iron homeostasis and transferrin gene expression in sheep: A preliminary study

The present research aimed at evaluating the effects of sodium selenite and selenium nanoparticles (Se NPs) on iron homeostasis and the expression of transferrin and its receptor-binding protein genes. Twenty one Lori–Bakhtiary sheep were randomly allocated into 3 groups. Groups 1 and 2 orally received Se NPs and sodium selenite (1 mg kg�1) for 10 consecutive days, respectively. Group 3 served as the control. Blood and sternal bone marrow samples were collected at different supplementation intervals. Various factors such as serum iron concentration, total iron binding capacity (TIBC), and transferrin saturation percent were determined. The expression of transferrin and transferrin binding receptor genes was also studied. Results showed a decreasing trend in serum iron concentration particularly during the early and middle stages of supplementation (0–20 days) with Se NPs or selenium ions. Conversely, the TIBC level increased in sera especially during these periods (0–20 days) in animals that received selenium NPs or selenium ions. Our results also showed that expression of transferrin and its receptor genes was considerably increased during supplementation of the animals by both selenium compounds for 10 or 20 days. After this period, the expression of the mentioned genes significantly decreased, especially in animals that received selenium ions

Biosynthesis and recovery of rod-shaped tellurium nanoparticles and their bactericidal activities

In this study, a tellurium-transforming Bacillus sp. BZ was isolated from the Caspian Sea in northern Iran. The isolate was identified by various tests and 16S rDNA analysis, and then used to prepare elemental tellurium nanoparticles. The isolate was subsequently used for the intracellular biosynthesis of elemental tellurium nanoparticles. The biogenic nanoparticles were released by liquid nitrogen and purified by an n-octyl alcohol water extraction system. The shape, size, and composition of the extracted nanoparticles were characterized. The transmission electron micrograph showed rod-shaped nanoparticles with dimensions of about 20 nm � 180 nm. The energy dispersive X-ray and X-ray diffraction spectra respectively demonstrated that the extracted nanoparticles consisted of only tellurium and have a hexagonal crystal structure. This is the first study to demonstrate a biological method for synthesizing rod-shaped elemental tellurium by a Bacillus sp., its extraction and its antibacterial activity against different clinical isolates

Synthesis and antibacterial activity of a Fe3O4–AgCl nanocomposite against Escherichia coli

In this investigation, Fe3O4 magnetic nanoparticles (MNPs) were prepared by the alkalinization of an aqueous medium containing ferrous sulfate and ferric chloride. In the next step, a Fe3O4–AgCl magnetic nanocomposite was fabricated by the drop-by-drop addition of silver nitrate solution into a NaCl solution containing Fe3O4 MNPs. All prepared nanoparticles were characterized by transition electron microscopy (TEM), X-ray diffraction (XRD), and energydispersive X-ray spectroscopy (EDS). Both particle types varied in size from 2.5 to 20 nm, with an average size of 7.5 nm for Fe3O4 MNPs and 12.5nm for Fe3O4– AgCl nanocomposites. The antibacterial effect of the Fe3O4 MNPs and fabricated Fe3O4–AgCl nanocomposites against Escherichia coli (ATCC 35218) were investigated by conventional serial agar dilution method using the Mu¨ ller– Hinton Agar medium. The minimum inhibitory concentration was 4 mgmL�1 for Fe3O4 MNPs and 2mgmL�1 for the Fe3O4–AgCl magnetic nanocomposites. Time-kill course assays showed that the Fe3O4–AgCl magnetic nanocomposites successfully killed all inoculated bacterial cells during an exposure time of 60 min. The antibacterial activity of recycled Fe3O4–AgCl magnetic nanocomposites over four 60 min cycles of antibacterial treatment was further tested against E. coli by the colony-forming unit (CFU) method. The antibacterial efficiency of the nanocomposites was constant over two cycles of antibacterial testing

Efficacy of biogenic selenium nanoparticles against Leishmania major: In vitro andin vivo studies

Project: This study investigated the in vitro and in vivo effectiveness of biogenic selenium nanoparticles(Se NPs), biosynthesized by Bacillus sp. MSh-1, against Leishmania major (MRHO/IR/75/ER). Procedure:The 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to evaluatethe cytotoxicity effects of the biogenic Se NPs against both promastigote and amastigote forms of L.major. In a separate in vivo experiment, we also determined the preventive and therapeutic effects ofbiogenic Se NPs in BALB/c mice following subcutaneous infected with L. major. Results: The MTT assaysshowed that the highest toxicity occurred after 72 h against both promastigote and amastigote formsof L. major. The cytotoxicity of Se NPs was higher at all incubation times (24, 48, and 72 h) against thepromastigote than the amastigote form (p < 0.05). The 50% inhibitory concentrations (IC50) of the Se NPswere 1.62 ± 0.6 and 4.4 ± 0.6 �g ml−1against the promastigote and amastigote forms, respectively, aftera 72-h incubation period. Apoptosis assays showed DNA fragmentation in promastigotes treated with SeNPs. In an animal challenge, prophylactic doses of biogenic Se NPs delayed the development of localizedcutaneous lesions. Moreover, daily administration of Se NPs (5 or 10 mg kg−1day−1) in similarly infectedBALB/c mice that had not received prophylactic doses of Se NPs also abolished the localized lesions after14 days. Conclusion: Based on these in vitro and in vivo studies, biogenic Se NPs can be considered as anovel therapeutic agent for treatment of the localized lesions typical of cutaneous leishmaniasis

Green synthesis of gold nanoparticles by the marine microalga Tetraselmis suecica

The application of green-synthesis principles is one of the most impressive research fields for the production of nanoparticles. Different kinds of biological systems have been used for this purpose. In the present study, AuNPs (gold nanoparticles) were prepared within a short time period using a fresh cell extract of the marine microalga Tetraselmis suecica as a reducing agent of HAuCl4 (chloroauric acid) solution. The UV–visible spectrum of the aqueous medium containing AuNPs indicated a peak at 530 nm, corresponding to the surface plasmon absorbance of AuNPs. The X-ray diffraction pattern also showed a Bragg reflection related to AuNPs. Fourier-transform infrared spectroscopy was performed for analysis of surface functional groups of AuNPs. Transmission electron microscopy and particle-size-distribution patterns determined by the laser-light-scattering method confirmed the formation of well-dispersed AuNPs. The most frequent size of particles was 79 nm

Isolation, characterization and complete genome sequence of PhaxI: a phage of Escherichia coli O157 :H7

Bacteriophages are considered as promising biological agents for the control of infectious diseases. Sequencing of their genomes can ascertain the absence of antibiotic resistance, toxin or virulence genes. The anti-O157 :H7 coliphage, PhaxI, was isolated from a sewage sample in Iran. Morphological studies by transmission electron microscopy showed that it has an icosahedral capsid of 85–86 nm and a contractile tail of 115�15 nm. PhaxI contains dsDNA composed of 156 628 nt with a G+C content of 44.5 mol% that encodes 209 putative proteins. In MS analysis of phage particles, 92 structural proteins were identified. PhaxI lyses Escherichia coli O157 :H7 in Luria-Bertani medium and milk, has an eclipse period of 20 min and a latent period of 40 min, and has a burst size of about 420 particles per cell. PhaxI is a member of the genus ‘Viunalikevirus’ of the family Myoviridae and is specific for E. coli O157 : H7