Monitoring of DNA structural changes after incorporation of the phenylpyrazole insecticide fipronil.

The use of insecticides presents a risk to the environment because they can accumulate in the water, soil, air, and organisms, endangering human and animal health. It is therefore essential to investigate the effects of different groups of insecticides on individual biomacromolecules such as DNA. We studied fipronil, which belongs to the group of phenylpyrazole insecticides. The interaction of fipronil with calf thymus DNA was investigated using spectroscopic methods (absorption and fluorescence spectroscopy) complemented with infrared spectroscopy and viscosity measurement. Fluorescence emission spectroscopy showed the formation of a fipronil/DNA complex with a combined static and dynamic type of quenching. The binding constant was 4.15 × 103 L/mol. Viscosity changes were recorded to confirm/disconfirm the intercalation mode of interaction. A slight change in DNA viscosity in the presence of fipronil was observed. The phenylpyrazole insecticide does not cause significant conformational changes in DNA structure or increase of its chain length. We hypothesize that fipronil is incorporated into the minor groove of the DNA macromolecule via hydrogen interactions as indicated by FT-IR and CD measurements.

Antiadhesive, antibiofilm and dispersion activity of biosurfactants isolated from Bacillus amyloliquefaciens 3/22.

The aim of this work was to monitor the potential antibiofilm properties of biosurfactants (BS) isolated from Bacillus amyloliquefaciens 3/22 against biofilm formation of the indicator strain Staphylococcus aureus CCM 4223. In this work, the effect of BS 3/22 on biofilm growth during co-incubation, inhibition of biofilm-forming cell adhesion and biofilm dispersion was studied. BS 3/22 inhibited biofilm formation, with its formation decreasing significantly (p < 0.05; p < 0.01; p < 0.001) with increasing BS 3/22 concentration. BS 3/22 also showed antiadhesive activity, which correlated with the concentration used. The dispersing effect of isolated BS 3/22 on a 24-hour biofilm was also detected. BS 3/22 were effective in biofilm dispersion even at lower concentrations compared to antiadhesive activity and inhibition of biofilm formation.

Antiadhesive, antibiofilm and dispersion activity of biosurfactants isolated from Bacillus amyloliquefaciens 3/22.

The aim of this work was to monitor the potential antibiofilm properties of biosurfactants (BS) isolated from Bacillus amyloliquefaciens 3/22 against biofilm formation of the indicator strain Staphylococcus aureus CCM 4223. In this work, the effect of BS 3/22 on biofilm growth during co-incubation, inhibition of biofilm-forming cell adhesion and biofilm dispersion was studied. BS 3/22 inhibited biofilm formation, with its formation decreasing significantly (p < 0.05; p < 0.01; p < 0.001) with increasing BS 3/22 concentration. BS 3/22 also showed antiadhesive activity, which correlated with the concentration used. The dispersing effect of isolated BS 3/22 on a 24-hour biofilm was also detected. BS 3/22 were effective in biofilm dispersion even at lower concentrations compared to antiadhesive activity and inhibition of biofilm formation.

A Brief Overview on Antioxidant Activity Determination of Silver Nanoparticles.

Our objective in this review article is to find out relevant information about methods of determination of antioxidant activity of silver nanoparticles. There are many studies dealing with mentioned problem and herein we summarize the knowledge about methods evaluating the antioxidant activity of silver nanoparticles reported so far. Many authors declare better antioxidant activity of silver nanoparticles compared to the extract used for synthesis of them. In this review, we focused on methods of antioxidant activity determination in detail to find out novel and perspective techniques to solve the general problems associated with the determination of antioxidant activity of silver nanoparticles.

The Role of Silver Nanoparticles in the Diagnosis and Treatment of Cancer: Are There Any Perspectives for the Future?

Cancer is a fatal disease with a complex pathophysiology. Lack of specificity and cytotoxicity, as well as the multidrug resistance of traditional cancer chemotherapy, are the most common limitations that often cause treatment failure. Thus, in recent years, significant efforts have concentrated on the development of a modernistic field called nano-oncology, which provides the possibility of using nanoparticles (NPs) with the aim to detect, target, and treat cancer diseases. In comparison with conventional anticancer strategies, NPs provide a targeted approach, preventing undesirable side effects. What is more, nanoparticle-based drug delivery systems have shown good pharmacokinetics and precise targeting, as well as reduced multidrug resistance. It has been documented that, in cancer cells, NPs promote reactive oxygen species (ROS) production, induce cell cycle arrest and apoptosis, activate ER (endoplasmic reticulum) stress, modulate various signaling pathways, etc. Furthermore, their ability to inhibit tumor growth in vivo has also been documented. In this paper, we have reviewed the role of silver NPs (AgNPs) in cancer nanomedicine, discussing numerous mechanisms by which they render anticancer properties under both in vitro and in vivo conditions, as well as their potential in the diagnosis of cancer.

Antiproliferative Effect of Phellodendron amurense Rupr. Based on Angiogenesis.

Phellodendron amurense Rupr. is medicinal plant used for supplemental therapy of various diseases based on their positive biological activities. The aim of this study was evaluated the main metabolite, safety of application and anticancer potential. Berberine was determined by HPLC as main alkaloid. Harmful character was determined by irritation test in ovo. The potential cancerogenic effect was studied in vitro on a cellular level, in ovo by CAM assay and in vivo on whole organism Artemia franciscana. Extract from the bark of Phellodendron amurense showed antiproliferative and antiangiogenic effects. The results of our work showed promising anticancer effects based also on the inhibition of angiogenesis with minimum negative effects.

Green Synthesis of Silver Nanoparticles with Antibacterial Activity Using Various Medicinal Plant Extracts: Morphology and Antibacterial Efficacy.

A green synthetic route for the production of silver nanoparticles (AgNPs) using five different aqueous plant extracts, namely, Berberis vulgaris, Brassica nigra, Capsella bursa-pastoris, Lavandula angustifolia and Origanum vulgare, was investigated in this study. The present work demonstrates the influence of plant extract composition (antioxidant and total phenolic content) on the size and morphology of the produced AgNPs. The biosynthetic procedure was rapid and simple and was easily monitored via colour changes and ultraviolet and visible (UV-Vis) spectroscopy. Subsequently, measurement of zeta potential (ZP), photon cross-correlation spectroscopy (PCCS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) analysis were employed to characterise the as-synthesised nanoparticles. The XRD investigation confirmed the presence of Ag0 in the nanoparticles, and interactions between the bioactive compounds of the plants and the produced AgNPs were evident in the FTIR spectra. TEM indicated that the nanoparticles exhibited a bimodal size distribution, with the smaller particles being spherical and the larger having a truncated octahedron shape. In addition, the antimicrobial activity of the AgNPs was tested against five bacterial strains. All synthesised nanoparticles exhibited enhanced antimicrobial activity at a precursor concentration of 5 mM compared to the control substance, gentamicin sulphate, with the best results observed for AgNPs prepared with B. nigra and L. angustifolia extracts.

Bacillus amyloliquefaciens-Derived Lipopeptide Biosurfactants Inhibit Biofilm Formation and Expression of Biofilm-Related Genes of Staphylococcus aureus.

Biosurfactants (BSs) are surface-active compounds produced by diverse microorganisms, including the genus Bacillus. These bioactive compounds possess biological activities such as antiadhesive, antimicrobial and antibiofilm effects that can lead to important applications in combating many infections. Based on these findings, we decided to investigate the antibiofilm activity of BSs from the marine Bacillus amyloliquefaciens against Staphylococcus aureus CCM 4223. Expression of biofilm-related genes was also evaluated using qRT-PCR. Isolated and partially purified BSs were identified and characterized by molecular tools and by UHPLC-DAD and MALDI-TOF/MS. Bacillus amyloliquefaciens 3/22, that exhibited surfactant activity evaluated by oil spreading assay, was characterized using the 16S rRNA sequencing method. Screening by PCR detected the presence of the sfp, srfAA, fenD and ituD genes, suggesting production of the lipopeptides (LPs) surfactin, fengycin and iturin. The above findings were further supported by the results of UHPLC-DAD and MALDI-TOF/MS. As quantified by the crystal violet method, the LPs significantly (p < 0.001) reduced biofilm formation of S. aureus in a dose-dependent manner and decreased expression of biofilm-related genes fnbA, fnbB, sortaseA and icaADBC operon. Data from our investigation indicate a promising therapeutic application for LPs isolated from B. amyloliquefaciens toward prevention of S. aureus biofilm infections.

Mechanochemistry as an Alternative Method of Green Synthesis of Silver Nanoparticles with Antibacterial Activity: A Comparative Study.

This study shows mechanochemical synthesis as an alternative method to the traditional green synthesis of silver nanoparticles in a comparative manner by comparing the products obtained using both methodologies and different characterization methods. As a silver precursor, the most commonly used silver nitrate was applied and the easily accessible lavender (Lavandula angustofolia L.) plant was used as a reducing agent. Both syntheses were performed using 7 different lavender:AgNO3 mass ratios. The synthesis time was limited to 8 and 15 min in the case of green and mechanochemical synthesis, respectively, although a significant amount of unreacted silver nitrate was detected in both crude reaction mixtures at low lavender:AgNO3 ratios. This finding is of particular interest mainly for green synthesis, as the potential presence of silver nitrate in the produced nanosuspension is often overlooked. Unreacted AgNO3 has been removed from the mechanochemically synthesized samples by washing. The nanocrystalline character of the products has been confirmed by both X-ray diffraction (Rietveld refinement) and transmission electron microscopy. The latter has shown bimodal size distribution with larger particles in tens of nanometers and the smaller ones below 10 nm in size. In the case of green synthesis, the used lavender:AgNO3 ratio was found to have a decisive role on the crystallite size. Silver chloride has been detected as a side-product, mainly at high lavender:AgNO3 ratios. Both products have shown a strong antibacterial activity, being higher in the case of green synthesis, but this can be ascribed to the presence of unreacted AgNO3. Thus, one-step mechanochemical synthesis (without the need to prepare extract and performing the synthesis as separate steps) can be applied as a sustainable alternative to the traditional green synthesis of Ag nanoparticles using plants.